1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/kernel.h> 20 #include <linux/bio.h> 21 #include <linux/buffer_head.h> 22 #include <linux/file.h> 23 #include <linux/fs.h> 24 #include <linux/pagemap.h> 25 #include <linux/highmem.h> 26 #include <linux/time.h> 27 #include <linux/init.h> 28 #include <linux/string.h> 29 #include <linux/backing-dev.h> 30 #include <linux/mpage.h> 31 #include <linux/swap.h> 32 #include <linux/writeback.h> 33 #include <linux/compat.h> 34 #include <linux/bit_spinlock.h> 35 #include <linux/xattr.h> 36 #include <linux/posix_acl.h> 37 #include <linux/falloc.h> 38 #include <linux/slab.h> 39 #include <linux/ratelimit.h> 40 #include <linux/mount.h> 41 #include <linux/btrfs.h> 42 #include <linux/blkdev.h> 43 #include <linux/posix_acl_xattr.h> 44 #include <linux/uio.h> 45 #include "ctree.h" 46 #include "disk-io.h" 47 #include "transaction.h" 48 #include "btrfs_inode.h" 49 #include "print-tree.h" 50 #include "ordered-data.h" 51 #include "xattr.h" 52 #include "tree-log.h" 53 #include "volumes.h" 54 #include "compression.h" 55 #include "locking.h" 56 #include "free-space-cache.h" 57 #include "inode-map.h" 58 #include "backref.h" 59 #include "hash.h" 60 #include "props.h" 61 #include "qgroup.h" 62 #include "dedupe.h" 63 64 struct btrfs_iget_args { 65 struct btrfs_key *location; 66 struct btrfs_root *root; 67 }; 68 69 struct btrfs_dio_data { 70 u64 outstanding_extents; 71 u64 reserve; 72 u64 unsubmitted_oe_range_start; 73 u64 unsubmitted_oe_range_end; 74 int overwrite; 75 }; 76 77 static const struct inode_operations btrfs_dir_inode_operations; 78 static const struct inode_operations btrfs_symlink_inode_operations; 79 static const struct inode_operations btrfs_dir_ro_inode_operations; 80 static const struct inode_operations btrfs_special_inode_operations; 81 static const struct inode_operations btrfs_file_inode_operations; 82 static const struct address_space_operations btrfs_aops; 83 static const struct address_space_operations btrfs_symlink_aops; 84 static const struct file_operations btrfs_dir_file_operations; 85 static const struct extent_io_ops btrfs_extent_io_ops; 86 87 static struct kmem_cache *btrfs_inode_cachep; 88 struct kmem_cache *btrfs_trans_handle_cachep; 89 struct kmem_cache *btrfs_transaction_cachep; 90 struct kmem_cache *btrfs_path_cachep; 91 struct kmem_cache *btrfs_free_space_cachep; 92 93 #define S_SHIFT 12 94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { 95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, 96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, 97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, 98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, 99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, 100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, 101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, 102 }; 103 104 static int btrfs_setsize(struct inode *inode, struct iattr *attr); 105 static int btrfs_truncate(struct inode *inode); 106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); 107 static noinline int cow_file_range(struct inode *inode, 108 struct page *locked_page, 109 u64 start, u64 end, u64 delalloc_end, 110 int *page_started, unsigned long *nr_written, 111 int unlock, struct btrfs_dedupe_hash *hash); 112 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len, 113 u64 orig_start, u64 block_start, 114 u64 block_len, u64 orig_block_len, 115 u64 ram_bytes, int compress_type, 116 int type); 117 118 static int btrfs_dirty_inode(struct inode *inode); 119 120 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 121 void btrfs_test_inode_set_ops(struct inode *inode) 122 { 123 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 124 } 125 #endif 126 127 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, 128 struct inode *inode, struct inode *dir, 129 const struct qstr *qstr) 130 { 131 int err; 132 133 err = btrfs_init_acl(trans, inode, dir); 134 if (!err) 135 err = btrfs_xattr_security_init(trans, inode, dir, qstr); 136 return err; 137 } 138 139 /* 140 * this does all the hard work for inserting an inline extent into 141 * the btree. The caller should have done a btrfs_drop_extents so that 142 * no overlapping inline items exist in the btree 143 */ 144 static int insert_inline_extent(struct btrfs_trans_handle *trans, 145 struct btrfs_path *path, int extent_inserted, 146 struct btrfs_root *root, struct inode *inode, 147 u64 start, size_t size, size_t compressed_size, 148 int compress_type, 149 struct page **compressed_pages) 150 { 151 struct extent_buffer *leaf; 152 struct page *page = NULL; 153 char *kaddr; 154 unsigned long ptr; 155 struct btrfs_file_extent_item *ei; 156 int err = 0; 157 int ret; 158 size_t cur_size = size; 159 unsigned long offset; 160 161 if (compressed_size && compressed_pages) 162 cur_size = compressed_size; 163 164 inode_add_bytes(inode, size); 165 166 if (!extent_inserted) { 167 struct btrfs_key key; 168 size_t datasize; 169 170 key.objectid = btrfs_ino(BTRFS_I(inode)); 171 key.offset = start; 172 key.type = BTRFS_EXTENT_DATA_KEY; 173 174 datasize = btrfs_file_extent_calc_inline_size(cur_size); 175 path->leave_spinning = 1; 176 ret = btrfs_insert_empty_item(trans, root, path, &key, 177 datasize); 178 if (ret) { 179 err = ret; 180 goto fail; 181 } 182 } 183 leaf = path->nodes[0]; 184 ei = btrfs_item_ptr(leaf, path->slots[0], 185 struct btrfs_file_extent_item); 186 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 187 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 188 btrfs_set_file_extent_encryption(leaf, ei, 0); 189 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 190 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 191 ptr = btrfs_file_extent_inline_start(ei); 192 193 if (compress_type != BTRFS_COMPRESS_NONE) { 194 struct page *cpage; 195 int i = 0; 196 while (compressed_size > 0) { 197 cpage = compressed_pages[i]; 198 cur_size = min_t(unsigned long, compressed_size, 199 PAGE_SIZE); 200 201 kaddr = kmap_atomic(cpage); 202 write_extent_buffer(leaf, kaddr, ptr, cur_size); 203 kunmap_atomic(kaddr); 204 205 i++; 206 ptr += cur_size; 207 compressed_size -= cur_size; 208 } 209 btrfs_set_file_extent_compression(leaf, ei, 210 compress_type); 211 } else { 212 page = find_get_page(inode->i_mapping, 213 start >> PAGE_SHIFT); 214 btrfs_set_file_extent_compression(leaf, ei, 0); 215 kaddr = kmap_atomic(page); 216 offset = start & (PAGE_SIZE - 1); 217 write_extent_buffer(leaf, kaddr + offset, ptr, size); 218 kunmap_atomic(kaddr); 219 put_page(page); 220 } 221 btrfs_mark_buffer_dirty(leaf); 222 btrfs_release_path(path); 223 224 /* 225 * we're an inline extent, so nobody can 226 * extend the file past i_size without locking 227 * a page we already have locked. 228 * 229 * We must do any isize and inode updates 230 * before we unlock the pages. Otherwise we 231 * could end up racing with unlink. 232 */ 233 BTRFS_I(inode)->disk_i_size = inode->i_size; 234 ret = btrfs_update_inode(trans, root, inode); 235 236 return ret; 237 fail: 238 return err; 239 } 240 241 242 /* 243 * conditionally insert an inline extent into the file. This 244 * does the checks required to make sure the data is small enough 245 * to fit as an inline extent. 246 */ 247 static noinline int cow_file_range_inline(struct btrfs_root *root, 248 struct inode *inode, u64 start, 249 u64 end, size_t compressed_size, 250 int compress_type, 251 struct page **compressed_pages) 252 { 253 struct btrfs_fs_info *fs_info = root->fs_info; 254 struct btrfs_trans_handle *trans; 255 u64 isize = i_size_read(inode); 256 u64 actual_end = min(end + 1, isize); 257 u64 inline_len = actual_end - start; 258 u64 aligned_end = ALIGN(end, fs_info->sectorsize); 259 u64 data_len = inline_len; 260 int ret; 261 struct btrfs_path *path; 262 int extent_inserted = 0; 263 u32 extent_item_size; 264 265 if (compressed_size) 266 data_len = compressed_size; 267 268 if (start > 0 || 269 actual_end > fs_info->sectorsize || 270 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) || 271 (!compressed_size && 272 (actual_end & (fs_info->sectorsize - 1)) == 0) || 273 end + 1 < isize || 274 data_len > fs_info->max_inline) { 275 return 1; 276 } 277 278 path = btrfs_alloc_path(); 279 if (!path) 280 return -ENOMEM; 281 282 trans = btrfs_join_transaction(root); 283 if (IS_ERR(trans)) { 284 btrfs_free_path(path); 285 return PTR_ERR(trans); 286 } 287 trans->block_rsv = &fs_info->delalloc_block_rsv; 288 289 if (compressed_size && compressed_pages) 290 extent_item_size = btrfs_file_extent_calc_inline_size( 291 compressed_size); 292 else 293 extent_item_size = btrfs_file_extent_calc_inline_size( 294 inline_len); 295 296 ret = __btrfs_drop_extents(trans, root, inode, path, 297 start, aligned_end, NULL, 298 1, 1, extent_item_size, &extent_inserted); 299 if (ret) { 300 btrfs_abort_transaction(trans, ret); 301 goto out; 302 } 303 304 if (isize > actual_end) 305 inline_len = min_t(u64, isize, actual_end); 306 ret = insert_inline_extent(trans, path, extent_inserted, 307 root, inode, start, 308 inline_len, compressed_size, 309 compress_type, compressed_pages); 310 if (ret && ret != -ENOSPC) { 311 btrfs_abort_transaction(trans, ret); 312 goto out; 313 } else if (ret == -ENOSPC) { 314 ret = 1; 315 goto out; 316 } 317 318 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 319 btrfs_delalloc_release_metadata(BTRFS_I(inode), end + 1 - start); 320 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0); 321 out: 322 /* 323 * Don't forget to free the reserved space, as for inlined extent 324 * it won't count as data extent, free them directly here. 325 * And at reserve time, it's always aligned to page size, so 326 * just free one page here. 327 */ 328 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE); 329 btrfs_free_path(path); 330 btrfs_end_transaction(trans); 331 return ret; 332 } 333 334 struct async_extent { 335 u64 start; 336 u64 ram_size; 337 u64 compressed_size; 338 struct page **pages; 339 unsigned long nr_pages; 340 int compress_type; 341 struct list_head list; 342 }; 343 344 struct async_cow { 345 struct inode *inode; 346 struct btrfs_root *root; 347 struct page *locked_page; 348 u64 start; 349 u64 end; 350 struct list_head extents; 351 struct btrfs_work work; 352 }; 353 354 static noinline int add_async_extent(struct async_cow *cow, 355 u64 start, u64 ram_size, 356 u64 compressed_size, 357 struct page **pages, 358 unsigned long nr_pages, 359 int compress_type) 360 { 361 struct async_extent *async_extent; 362 363 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 364 BUG_ON(!async_extent); /* -ENOMEM */ 365 async_extent->start = start; 366 async_extent->ram_size = ram_size; 367 async_extent->compressed_size = compressed_size; 368 async_extent->pages = pages; 369 async_extent->nr_pages = nr_pages; 370 async_extent->compress_type = compress_type; 371 list_add_tail(&async_extent->list, &cow->extents); 372 return 0; 373 } 374 375 static inline int inode_need_compress(struct inode *inode) 376 { 377 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 378 379 /* force compress */ 380 if (btrfs_test_opt(fs_info, FORCE_COMPRESS)) 381 return 1; 382 /* bad compression ratios */ 383 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 384 return 0; 385 if (btrfs_test_opt(fs_info, COMPRESS) || 386 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS || 387 BTRFS_I(inode)->force_compress) 388 return 1; 389 return 0; 390 } 391 392 static inline void inode_should_defrag(struct btrfs_inode *inode, 393 u64 start, u64 end, u64 num_bytes, u64 small_write) 394 { 395 /* If this is a small write inside eof, kick off a defrag */ 396 if (num_bytes < small_write && 397 (start > 0 || end + 1 < inode->disk_i_size)) 398 btrfs_add_inode_defrag(NULL, inode); 399 } 400 401 /* 402 * we create compressed extents in two phases. The first 403 * phase compresses a range of pages that have already been 404 * locked (both pages and state bits are locked). 405 * 406 * This is done inside an ordered work queue, and the compression 407 * is spread across many cpus. The actual IO submission is step 408 * two, and the ordered work queue takes care of making sure that 409 * happens in the same order things were put onto the queue by 410 * writepages and friends. 411 * 412 * If this code finds it can't get good compression, it puts an 413 * entry onto the work queue to write the uncompressed bytes. This 414 * makes sure that both compressed inodes and uncompressed inodes 415 * are written in the same order that the flusher thread sent them 416 * down. 417 */ 418 static noinline void compress_file_range(struct inode *inode, 419 struct page *locked_page, 420 u64 start, u64 end, 421 struct async_cow *async_cow, 422 int *num_added) 423 { 424 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 425 struct btrfs_root *root = BTRFS_I(inode)->root; 426 u64 num_bytes; 427 u64 blocksize = fs_info->sectorsize; 428 u64 actual_end; 429 u64 isize = i_size_read(inode); 430 int ret = 0; 431 struct page **pages = NULL; 432 unsigned long nr_pages; 433 unsigned long total_compressed = 0; 434 unsigned long total_in = 0; 435 int i; 436 int will_compress; 437 int compress_type = fs_info->compress_type; 438 int redirty = 0; 439 440 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1, 441 SZ_16K); 442 443 actual_end = min_t(u64, isize, end + 1); 444 again: 445 will_compress = 0; 446 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1; 447 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0); 448 nr_pages = min_t(unsigned long, nr_pages, 449 BTRFS_MAX_COMPRESSED / PAGE_SIZE); 450 451 /* 452 * we don't want to send crud past the end of i_size through 453 * compression, that's just a waste of CPU time. So, if the 454 * end of the file is before the start of our current 455 * requested range of bytes, we bail out to the uncompressed 456 * cleanup code that can deal with all of this. 457 * 458 * It isn't really the fastest way to fix things, but this is a 459 * very uncommon corner. 460 */ 461 if (actual_end <= start) 462 goto cleanup_and_bail_uncompressed; 463 464 total_compressed = actual_end - start; 465 466 /* 467 * skip compression for a small file range(<=blocksize) that 468 * isn't an inline extent, since it doesn't save disk space at all. 469 */ 470 if (total_compressed <= blocksize && 471 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 472 goto cleanup_and_bail_uncompressed; 473 474 total_compressed = min_t(unsigned long, total_compressed, 475 BTRFS_MAX_UNCOMPRESSED); 476 num_bytes = ALIGN(end - start + 1, blocksize); 477 num_bytes = max(blocksize, num_bytes); 478 total_in = 0; 479 ret = 0; 480 481 /* 482 * we do compression for mount -o compress and when the 483 * inode has not been flagged as nocompress. This flag can 484 * change at any time if we discover bad compression ratios. 485 */ 486 if (inode_need_compress(inode)) { 487 WARN_ON(pages); 488 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); 489 if (!pages) { 490 /* just bail out to the uncompressed code */ 491 goto cont; 492 } 493 494 if (BTRFS_I(inode)->force_compress) 495 compress_type = BTRFS_I(inode)->force_compress; 496 497 /* 498 * we need to call clear_page_dirty_for_io on each 499 * page in the range. Otherwise applications with the file 500 * mmap'd can wander in and change the page contents while 501 * we are compressing them. 502 * 503 * If the compression fails for any reason, we set the pages 504 * dirty again later on. 505 */ 506 extent_range_clear_dirty_for_io(inode, start, end); 507 redirty = 1; 508 ret = btrfs_compress_pages(compress_type, 509 inode->i_mapping, start, 510 pages, 511 &nr_pages, 512 &total_in, 513 &total_compressed); 514 515 if (!ret) { 516 unsigned long offset = total_compressed & 517 (PAGE_SIZE - 1); 518 struct page *page = pages[nr_pages - 1]; 519 char *kaddr; 520 521 /* zero the tail end of the last page, we might be 522 * sending it down to disk 523 */ 524 if (offset) { 525 kaddr = kmap_atomic(page); 526 memset(kaddr + offset, 0, 527 PAGE_SIZE - offset); 528 kunmap_atomic(kaddr); 529 } 530 will_compress = 1; 531 } 532 } 533 cont: 534 if (start == 0) { 535 /* lets try to make an inline extent */ 536 if (ret || total_in < (actual_end - start)) { 537 /* we didn't compress the entire range, try 538 * to make an uncompressed inline extent. 539 */ 540 ret = cow_file_range_inline(root, inode, start, end, 541 0, BTRFS_COMPRESS_NONE, NULL); 542 } else { 543 /* try making a compressed inline extent */ 544 ret = cow_file_range_inline(root, inode, start, end, 545 total_compressed, 546 compress_type, pages); 547 } 548 if (ret <= 0) { 549 unsigned long clear_flags = EXTENT_DELALLOC | 550 EXTENT_DEFRAG; 551 unsigned long page_error_op; 552 553 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0; 554 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0; 555 556 /* 557 * inline extent creation worked or returned error, 558 * we don't need to create any more async work items. 559 * Unlock and free up our temp pages. 560 */ 561 extent_clear_unlock_delalloc(inode, start, end, end, 562 NULL, clear_flags, 563 PAGE_UNLOCK | 564 PAGE_CLEAR_DIRTY | 565 PAGE_SET_WRITEBACK | 566 page_error_op | 567 PAGE_END_WRITEBACK); 568 btrfs_free_reserved_data_space_noquota(inode, start, 569 end - start + 1); 570 goto free_pages_out; 571 } 572 } 573 574 if (will_compress) { 575 /* 576 * we aren't doing an inline extent round the compressed size 577 * up to a block size boundary so the allocator does sane 578 * things 579 */ 580 total_compressed = ALIGN(total_compressed, blocksize); 581 582 /* 583 * one last check to make sure the compression is really a 584 * win, compare the page count read with the blocks on disk 585 */ 586 total_in = ALIGN(total_in, PAGE_SIZE); 587 if (total_compressed >= total_in) { 588 will_compress = 0; 589 } else { 590 num_bytes = total_in; 591 *num_added += 1; 592 593 /* 594 * The async work queues will take care of doing actual 595 * allocation on disk for these compressed pages, and 596 * will submit them to the elevator. 597 */ 598 add_async_extent(async_cow, start, num_bytes, 599 total_compressed, pages, nr_pages, 600 compress_type); 601 602 if (start + num_bytes < end) { 603 start += num_bytes; 604 pages = NULL; 605 cond_resched(); 606 goto again; 607 } 608 return; 609 } 610 } 611 if (pages) { 612 /* 613 * the compression code ran but failed to make things smaller, 614 * free any pages it allocated and our page pointer array 615 */ 616 for (i = 0; i < nr_pages; i++) { 617 WARN_ON(pages[i]->mapping); 618 put_page(pages[i]); 619 } 620 kfree(pages); 621 pages = NULL; 622 total_compressed = 0; 623 nr_pages = 0; 624 625 /* flag the file so we don't compress in the future */ 626 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) && 627 !(BTRFS_I(inode)->force_compress)) { 628 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 629 } 630 } 631 cleanup_and_bail_uncompressed: 632 /* 633 * No compression, but we still need to write the pages in the file 634 * we've been given so far. redirty the locked page if it corresponds 635 * to our extent and set things up for the async work queue to run 636 * cow_file_range to do the normal delalloc dance. 637 */ 638 if (page_offset(locked_page) >= start && 639 page_offset(locked_page) <= end) 640 __set_page_dirty_nobuffers(locked_page); 641 /* unlocked later on in the async handlers */ 642 643 if (redirty) 644 extent_range_redirty_for_io(inode, start, end); 645 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0, 646 BTRFS_COMPRESS_NONE); 647 *num_added += 1; 648 649 return; 650 651 free_pages_out: 652 for (i = 0; i < nr_pages; i++) { 653 WARN_ON(pages[i]->mapping); 654 put_page(pages[i]); 655 } 656 kfree(pages); 657 } 658 659 static void free_async_extent_pages(struct async_extent *async_extent) 660 { 661 int i; 662 663 if (!async_extent->pages) 664 return; 665 666 for (i = 0; i < async_extent->nr_pages; i++) { 667 WARN_ON(async_extent->pages[i]->mapping); 668 put_page(async_extent->pages[i]); 669 } 670 kfree(async_extent->pages); 671 async_extent->nr_pages = 0; 672 async_extent->pages = NULL; 673 } 674 675 /* 676 * phase two of compressed writeback. This is the ordered portion 677 * of the code, which only gets called in the order the work was 678 * queued. We walk all the async extents created by compress_file_range 679 * and send them down to the disk. 680 */ 681 static noinline void submit_compressed_extents(struct inode *inode, 682 struct async_cow *async_cow) 683 { 684 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 685 struct async_extent *async_extent; 686 u64 alloc_hint = 0; 687 struct btrfs_key ins; 688 struct extent_map *em; 689 struct btrfs_root *root = BTRFS_I(inode)->root; 690 struct extent_io_tree *io_tree; 691 int ret = 0; 692 693 again: 694 while (!list_empty(&async_cow->extents)) { 695 async_extent = list_entry(async_cow->extents.next, 696 struct async_extent, list); 697 list_del(&async_extent->list); 698 699 io_tree = &BTRFS_I(inode)->io_tree; 700 701 retry: 702 /* did the compression code fall back to uncompressed IO? */ 703 if (!async_extent->pages) { 704 int page_started = 0; 705 unsigned long nr_written = 0; 706 707 lock_extent(io_tree, async_extent->start, 708 async_extent->start + 709 async_extent->ram_size - 1); 710 711 /* allocate blocks */ 712 ret = cow_file_range(inode, async_cow->locked_page, 713 async_extent->start, 714 async_extent->start + 715 async_extent->ram_size - 1, 716 async_extent->start + 717 async_extent->ram_size - 1, 718 &page_started, &nr_written, 0, 719 NULL); 720 721 /* JDM XXX */ 722 723 /* 724 * if page_started, cow_file_range inserted an 725 * inline extent and took care of all the unlocking 726 * and IO for us. Otherwise, we need to submit 727 * all those pages down to the drive. 728 */ 729 if (!page_started && !ret) 730 extent_write_locked_range(io_tree, 731 inode, async_extent->start, 732 async_extent->start + 733 async_extent->ram_size - 1, 734 btrfs_get_extent, 735 WB_SYNC_ALL); 736 else if (ret) 737 unlock_page(async_cow->locked_page); 738 kfree(async_extent); 739 cond_resched(); 740 continue; 741 } 742 743 lock_extent(io_tree, async_extent->start, 744 async_extent->start + async_extent->ram_size - 1); 745 746 ret = btrfs_reserve_extent(root, async_extent->ram_size, 747 async_extent->compressed_size, 748 async_extent->compressed_size, 749 0, alloc_hint, &ins, 1, 1); 750 if (ret) { 751 free_async_extent_pages(async_extent); 752 753 if (ret == -ENOSPC) { 754 unlock_extent(io_tree, async_extent->start, 755 async_extent->start + 756 async_extent->ram_size - 1); 757 758 /* 759 * we need to redirty the pages if we decide to 760 * fallback to uncompressed IO, otherwise we 761 * will not submit these pages down to lower 762 * layers. 763 */ 764 extent_range_redirty_for_io(inode, 765 async_extent->start, 766 async_extent->start + 767 async_extent->ram_size - 1); 768 769 goto retry; 770 } 771 goto out_free; 772 } 773 /* 774 * here we're doing allocation and writeback of the 775 * compressed pages 776 */ 777 em = create_io_em(inode, async_extent->start, 778 async_extent->ram_size, /* len */ 779 async_extent->start, /* orig_start */ 780 ins.objectid, /* block_start */ 781 ins.offset, /* block_len */ 782 ins.offset, /* orig_block_len */ 783 async_extent->ram_size, /* ram_bytes */ 784 async_extent->compress_type, 785 BTRFS_ORDERED_COMPRESSED); 786 if (IS_ERR(em)) 787 /* ret value is not necessary due to void function */ 788 goto out_free_reserve; 789 free_extent_map(em); 790 791 ret = btrfs_add_ordered_extent_compress(inode, 792 async_extent->start, 793 ins.objectid, 794 async_extent->ram_size, 795 ins.offset, 796 BTRFS_ORDERED_COMPRESSED, 797 async_extent->compress_type); 798 if (ret) { 799 btrfs_drop_extent_cache(BTRFS_I(inode), 800 async_extent->start, 801 async_extent->start + 802 async_extent->ram_size - 1, 0); 803 goto out_free_reserve; 804 } 805 btrfs_dec_block_group_reservations(fs_info, ins.objectid); 806 807 /* 808 * clear dirty, set writeback and unlock the pages. 809 */ 810 extent_clear_unlock_delalloc(inode, async_extent->start, 811 async_extent->start + 812 async_extent->ram_size - 1, 813 async_extent->start + 814 async_extent->ram_size - 1, 815 NULL, EXTENT_LOCKED | EXTENT_DELALLOC, 816 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 817 PAGE_SET_WRITEBACK); 818 ret = btrfs_submit_compressed_write(inode, 819 async_extent->start, 820 async_extent->ram_size, 821 ins.objectid, 822 ins.offset, async_extent->pages, 823 async_extent->nr_pages); 824 if (ret) { 825 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; 826 struct page *p = async_extent->pages[0]; 827 const u64 start = async_extent->start; 828 const u64 end = start + async_extent->ram_size - 1; 829 830 p->mapping = inode->i_mapping; 831 tree->ops->writepage_end_io_hook(p, start, end, 832 NULL, 0); 833 p->mapping = NULL; 834 extent_clear_unlock_delalloc(inode, start, end, end, 835 NULL, 0, 836 PAGE_END_WRITEBACK | 837 PAGE_SET_ERROR); 838 free_async_extent_pages(async_extent); 839 } 840 alloc_hint = ins.objectid + ins.offset; 841 kfree(async_extent); 842 cond_resched(); 843 } 844 return; 845 out_free_reserve: 846 btrfs_dec_block_group_reservations(fs_info, ins.objectid); 847 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1); 848 out_free: 849 extent_clear_unlock_delalloc(inode, async_extent->start, 850 async_extent->start + 851 async_extent->ram_size - 1, 852 async_extent->start + 853 async_extent->ram_size - 1, 854 NULL, EXTENT_LOCKED | EXTENT_DELALLOC | 855 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, 856 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 857 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | 858 PAGE_SET_ERROR); 859 free_async_extent_pages(async_extent); 860 kfree(async_extent); 861 goto again; 862 } 863 864 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 865 u64 num_bytes) 866 { 867 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 868 struct extent_map *em; 869 u64 alloc_hint = 0; 870 871 read_lock(&em_tree->lock); 872 em = search_extent_mapping(em_tree, start, num_bytes); 873 if (em) { 874 /* 875 * if block start isn't an actual block number then find the 876 * first block in this inode and use that as a hint. If that 877 * block is also bogus then just don't worry about it. 878 */ 879 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 880 free_extent_map(em); 881 em = search_extent_mapping(em_tree, 0, 0); 882 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 883 alloc_hint = em->block_start; 884 if (em) 885 free_extent_map(em); 886 } else { 887 alloc_hint = em->block_start; 888 free_extent_map(em); 889 } 890 } 891 read_unlock(&em_tree->lock); 892 893 return alloc_hint; 894 } 895 896 /* 897 * when extent_io.c finds a delayed allocation range in the file, 898 * the call backs end up in this code. The basic idea is to 899 * allocate extents on disk for the range, and create ordered data structs 900 * in ram to track those extents. 901 * 902 * locked_page is the page that writepage had locked already. We use 903 * it to make sure we don't do extra locks or unlocks. 904 * 905 * *page_started is set to one if we unlock locked_page and do everything 906 * required to start IO on it. It may be clean and already done with 907 * IO when we return. 908 */ 909 static noinline int cow_file_range(struct inode *inode, 910 struct page *locked_page, 911 u64 start, u64 end, u64 delalloc_end, 912 int *page_started, unsigned long *nr_written, 913 int unlock, struct btrfs_dedupe_hash *hash) 914 { 915 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 916 struct btrfs_root *root = BTRFS_I(inode)->root; 917 u64 alloc_hint = 0; 918 u64 num_bytes; 919 unsigned long ram_size; 920 u64 disk_num_bytes; 921 u64 cur_alloc_size; 922 u64 blocksize = fs_info->sectorsize; 923 struct btrfs_key ins; 924 struct extent_map *em; 925 int ret = 0; 926 927 if (btrfs_is_free_space_inode(BTRFS_I(inode))) { 928 WARN_ON_ONCE(1); 929 ret = -EINVAL; 930 goto out_unlock; 931 } 932 933 num_bytes = ALIGN(end - start + 1, blocksize); 934 num_bytes = max(blocksize, num_bytes); 935 disk_num_bytes = num_bytes; 936 937 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K); 938 939 if (start == 0) { 940 /* lets try to make an inline extent */ 941 ret = cow_file_range_inline(root, inode, start, end, 0, 942 BTRFS_COMPRESS_NONE, NULL); 943 if (ret == 0) { 944 extent_clear_unlock_delalloc(inode, start, end, 945 delalloc_end, NULL, 946 EXTENT_LOCKED | EXTENT_DELALLOC | 947 EXTENT_DEFRAG, PAGE_UNLOCK | 948 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | 949 PAGE_END_WRITEBACK); 950 btrfs_free_reserved_data_space_noquota(inode, start, 951 end - start + 1); 952 *nr_written = *nr_written + 953 (end - start + PAGE_SIZE) / PAGE_SIZE; 954 *page_started = 1; 955 goto out; 956 } else if (ret < 0) { 957 goto out_unlock; 958 } 959 } 960 961 BUG_ON(disk_num_bytes > 962 btrfs_super_total_bytes(fs_info->super_copy)); 963 964 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 965 btrfs_drop_extent_cache(BTRFS_I(inode), start, 966 start + num_bytes - 1, 0); 967 968 while (disk_num_bytes > 0) { 969 unsigned long op; 970 971 cur_alloc_size = disk_num_bytes; 972 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size, 973 fs_info->sectorsize, 0, alloc_hint, 974 &ins, 1, 1); 975 if (ret < 0) 976 goto out_unlock; 977 978 ram_size = ins.offset; 979 em = create_io_em(inode, start, ins.offset, /* len */ 980 start, /* orig_start */ 981 ins.objectid, /* block_start */ 982 ins.offset, /* block_len */ 983 ins.offset, /* orig_block_len */ 984 ram_size, /* ram_bytes */ 985 BTRFS_COMPRESS_NONE, /* compress_type */ 986 BTRFS_ORDERED_REGULAR /* type */); 987 if (IS_ERR(em)) 988 goto out_reserve; 989 free_extent_map(em); 990 991 cur_alloc_size = ins.offset; 992 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 993 ram_size, cur_alloc_size, 0); 994 if (ret) 995 goto out_drop_extent_cache; 996 997 if (root->root_key.objectid == 998 BTRFS_DATA_RELOC_TREE_OBJECTID) { 999 ret = btrfs_reloc_clone_csums(inode, start, 1000 cur_alloc_size); 1001 if (ret) 1002 goto out_drop_extent_cache; 1003 } 1004 1005 btrfs_dec_block_group_reservations(fs_info, ins.objectid); 1006 1007 if (disk_num_bytes < cur_alloc_size) 1008 break; 1009 1010 /* we're not doing compressed IO, don't unlock the first 1011 * page (which the caller expects to stay locked), don't 1012 * clear any dirty bits and don't set any writeback bits 1013 * 1014 * Do set the Private2 bit so we know this page was properly 1015 * setup for writepage 1016 */ 1017 op = unlock ? PAGE_UNLOCK : 0; 1018 op |= PAGE_SET_PRIVATE2; 1019 1020 extent_clear_unlock_delalloc(inode, start, 1021 start + ram_size - 1, 1022 delalloc_end, locked_page, 1023 EXTENT_LOCKED | EXTENT_DELALLOC, 1024 op); 1025 disk_num_bytes -= cur_alloc_size; 1026 num_bytes -= cur_alloc_size; 1027 alloc_hint = ins.objectid + ins.offset; 1028 start += cur_alloc_size; 1029 } 1030 out: 1031 return ret; 1032 1033 out_drop_extent_cache: 1034 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0); 1035 out_reserve: 1036 btrfs_dec_block_group_reservations(fs_info, ins.objectid); 1037 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1); 1038 out_unlock: 1039 extent_clear_unlock_delalloc(inode, start, end, delalloc_end, 1040 locked_page, 1041 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 1042 EXTENT_DELALLOC | EXTENT_DEFRAG, 1043 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 1044 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 1045 goto out; 1046 } 1047 1048 /* 1049 * work queue call back to started compression on a file and pages 1050 */ 1051 static noinline void async_cow_start(struct btrfs_work *work) 1052 { 1053 struct async_cow *async_cow; 1054 int num_added = 0; 1055 async_cow = container_of(work, struct async_cow, work); 1056 1057 compress_file_range(async_cow->inode, async_cow->locked_page, 1058 async_cow->start, async_cow->end, async_cow, 1059 &num_added); 1060 if (num_added == 0) { 1061 btrfs_add_delayed_iput(async_cow->inode); 1062 async_cow->inode = NULL; 1063 } 1064 } 1065 1066 /* 1067 * work queue call back to submit previously compressed pages 1068 */ 1069 static noinline void async_cow_submit(struct btrfs_work *work) 1070 { 1071 struct btrfs_fs_info *fs_info; 1072 struct async_cow *async_cow; 1073 struct btrfs_root *root; 1074 unsigned long nr_pages; 1075 1076 async_cow = container_of(work, struct async_cow, work); 1077 1078 root = async_cow->root; 1079 fs_info = root->fs_info; 1080 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >> 1081 PAGE_SHIFT; 1082 1083 /* 1084 * atomic_sub_return implies a barrier for waitqueue_active 1085 */ 1086 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) < 1087 5 * SZ_1M && 1088 waitqueue_active(&fs_info->async_submit_wait)) 1089 wake_up(&fs_info->async_submit_wait); 1090 1091 if (async_cow->inode) 1092 submit_compressed_extents(async_cow->inode, async_cow); 1093 } 1094 1095 static noinline void async_cow_free(struct btrfs_work *work) 1096 { 1097 struct async_cow *async_cow; 1098 async_cow = container_of(work, struct async_cow, work); 1099 if (async_cow->inode) 1100 btrfs_add_delayed_iput(async_cow->inode); 1101 kfree(async_cow); 1102 } 1103 1104 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1105 u64 start, u64 end, int *page_started, 1106 unsigned long *nr_written) 1107 { 1108 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1109 struct async_cow *async_cow; 1110 struct btrfs_root *root = BTRFS_I(inode)->root; 1111 unsigned long nr_pages; 1112 u64 cur_end; 1113 1114 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1115 1, 0, NULL, GFP_NOFS); 1116 while (start < end) { 1117 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1118 BUG_ON(!async_cow); /* -ENOMEM */ 1119 async_cow->inode = igrab(inode); 1120 async_cow->root = root; 1121 async_cow->locked_page = locked_page; 1122 async_cow->start = start; 1123 1124 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS && 1125 !btrfs_test_opt(fs_info, FORCE_COMPRESS)) 1126 cur_end = end; 1127 else 1128 cur_end = min(end, start + SZ_512K - 1); 1129 1130 async_cow->end = cur_end; 1131 INIT_LIST_HEAD(&async_cow->extents); 1132 1133 btrfs_init_work(&async_cow->work, 1134 btrfs_delalloc_helper, 1135 async_cow_start, async_cow_submit, 1136 async_cow_free); 1137 1138 nr_pages = (cur_end - start + PAGE_SIZE) >> 1139 PAGE_SHIFT; 1140 atomic_add(nr_pages, &fs_info->async_delalloc_pages); 1141 1142 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work); 1143 1144 while (atomic_read(&fs_info->async_submit_draining) && 1145 atomic_read(&fs_info->async_delalloc_pages)) { 1146 wait_event(fs_info->async_submit_wait, 1147 (atomic_read(&fs_info->async_delalloc_pages) == 1148 0)); 1149 } 1150 1151 *nr_written += nr_pages; 1152 start = cur_end + 1; 1153 } 1154 *page_started = 1; 1155 return 0; 1156 } 1157 1158 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info, 1159 u64 bytenr, u64 num_bytes) 1160 { 1161 int ret; 1162 struct btrfs_ordered_sum *sums; 1163 LIST_HEAD(list); 1164 1165 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr, 1166 bytenr + num_bytes - 1, &list, 0); 1167 if (ret == 0 && list_empty(&list)) 1168 return 0; 1169 1170 while (!list_empty(&list)) { 1171 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1172 list_del(&sums->list); 1173 kfree(sums); 1174 } 1175 return 1; 1176 } 1177 1178 /* 1179 * when nowcow writeback call back. This checks for snapshots or COW copies 1180 * of the extents that exist in the file, and COWs the file as required. 1181 * 1182 * If no cow copies or snapshots exist, we write directly to the existing 1183 * blocks on disk 1184 */ 1185 static noinline int run_delalloc_nocow(struct inode *inode, 1186 struct page *locked_page, 1187 u64 start, u64 end, int *page_started, int force, 1188 unsigned long *nr_written) 1189 { 1190 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1191 struct btrfs_root *root = BTRFS_I(inode)->root; 1192 struct extent_buffer *leaf; 1193 struct btrfs_path *path; 1194 struct btrfs_file_extent_item *fi; 1195 struct btrfs_key found_key; 1196 struct extent_map *em; 1197 u64 cow_start; 1198 u64 cur_offset; 1199 u64 extent_end; 1200 u64 extent_offset; 1201 u64 disk_bytenr; 1202 u64 num_bytes; 1203 u64 disk_num_bytes; 1204 u64 ram_bytes; 1205 int extent_type; 1206 int ret, err; 1207 int type; 1208 int nocow; 1209 int check_prev = 1; 1210 bool nolock; 1211 u64 ino = btrfs_ino(BTRFS_I(inode)); 1212 1213 path = btrfs_alloc_path(); 1214 if (!path) { 1215 extent_clear_unlock_delalloc(inode, start, end, end, 1216 locked_page, 1217 EXTENT_LOCKED | EXTENT_DELALLOC | 1218 EXTENT_DO_ACCOUNTING | 1219 EXTENT_DEFRAG, PAGE_UNLOCK | 1220 PAGE_CLEAR_DIRTY | 1221 PAGE_SET_WRITEBACK | 1222 PAGE_END_WRITEBACK); 1223 return -ENOMEM; 1224 } 1225 1226 nolock = btrfs_is_free_space_inode(BTRFS_I(inode)); 1227 1228 cow_start = (u64)-1; 1229 cur_offset = start; 1230 while (1) { 1231 ret = btrfs_lookup_file_extent(NULL, root, path, ino, 1232 cur_offset, 0); 1233 if (ret < 0) 1234 goto error; 1235 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1236 leaf = path->nodes[0]; 1237 btrfs_item_key_to_cpu(leaf, &found_key, 1238 path->slots[0] - 1); 1239 if (found_key.objectid == ino && 1240 found_key.type == BTRFS_EXTENT_DATA_KEY) 1241 path->slots[0]--; 1242 } 1243 check_prev = 0; 1244 next_slot: 1245 leaf = path->nodes[0]; 1246 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1247 ret = btrfs_next_leaf(root, path); 1248 if (ret < 0) 1249 goto error; 1250 if (ret > 0) 1251 break; 1252 leaf = path->nodes[0]; 1253 } 1254 1255 nocow = 0; 1256 disk_bytenr = 0; 1257 num_bytes = 0; 1258 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1259 1260 if (found_key.objectid > ino) 1261 break; 1262 if (WARN_ON_ONCE(found_key.objectid < ino) || 1263 found_key.type < BTRFS_EXTENT_DATA_KEY) { 1264 path->slots[0]++; 1265 goto next_slot; 1266 } 1267 if (found_key.type > BTRFS_EXTENT_DATA_KEY || 1268 found_key.offset > end) 1269 break; 1270 1271 if (found_key.offset > cur_offset) { 1272 extent_end = found_key.offset; 1273 extent_type = 0; 1274 goto out_check; 1275 } 1276 1277 fi = btrfs_item_ptr(leaf, path->slots[0], 1278 struct btrfs_file_extent_item); 1279 extent_type = btrfs_file_extent_type(leaf, fi); 1280 1281 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1282 if (extent_type == BTRFS_FILE_EXTENT_REG || 1283 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1284 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1285 extent_offset = btrfs_file_extent_offset(leaf, fi); 1286 extent_end = found_key.offset + 1287 btrfs_file_extent_num_bytes(leaf, fi); 1288 disk_num_bytes = 1289 btrfs_file_extent_disk_num_bytes(leaf, fi); 1290 if (extent_end <= start) { 1291 path->slots[0]++; 1292 goto next_slot; 1293 } 1294 if (disk_bytenr == 0) 1295 goto out_check; 1296 if (btrfs_file_extent_compression(leaf, fi) || 1297 btrfs_file_extent_encryption(leaf, fi) || 1298 btrfs_file_extent_other_encoding(leaf, fi)) 1299 goto out_check; 1300 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1301 goto out_check; 1302 if (btrfs_extent_readonly(fs_info, disk_bytenr)) 1303 goto out_check; 1304 if (btrfs_cross_ref_exist(root, ino, 1305 found_key.offset - 1306 extent_offset, disk_bytenr)) 1307 goto out_check; 1308 disk_bytenr += extent_offset; 1309 disk_bytenr += cur_offset - found_key.offset; 1310 num_bytes = min(end + 1, extent_end) - cur_offset; 1311 /* 1312 * if there are pending snapshots for this root, 1313 * we fall into common COW way. 1314 */ 1315 if (!nolock) { 1316 err = btrfs_start_write_no_snapshoting(root); 1317 if (!err) 1318 goto out_check; 1319 } 1320 /* 1321 * force cow if csum exists in the range. 1322 * this ensure that csum for a given extent are 1323 * either valid or do not exist. 1324 */ 1325 if (csum_exist_in_range(fs_info, disk_bytenr, 1326 num_bytes)) { 1327 if (!nolock) 1328 btrfs_end_write_no_snapshoting(root); 1329 goto out_check; 1330 } 1331 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) { 1332 if (!nolock) 1333 btrfs_end_write_no_snapshoting(root); 1334 goto out_check; 1335 } 1336 nocow = 1; 1337 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1338 extent_end = found_key.offset + 1339 btrfs_file_extent_inline_len(leaf, 1340 path->slots[0], fi); 1341 extent_end = ALIGN(extent_end, 1342 fs_info->sectorsize); 1343 } else { 1344 BUG_ON(1); 1345 } 1346 out_check: 1347 if (extent_end <= start) { 1348 path->slots[0]++; 1349 if (!nolock && nocow) 1350 btrfs_end_write_no_snapshoting(root); 1351 if (nocow) 1352 btrfs_dec_nocow_writers(fs_info, disk_bytenr); 1353 goto next_slot; 1354 } 1355 if (!nocow) { 1356 if (cow_start == (u64)-1) 1357 cow_start = cur_offset; 1358 cur_offset = extent_end; 1359 if (cur_offset > end) 1360 break; 1361 path->slots[0]++; 1362 goto next_slot; 1363 } 1364 1365 btrfs_release_path(path); 1366 if (cow_start != (u64)-1) { 1367 ret = cow_file_range(inode, locked_page, 1368 cow_start, found_key.offset - 1, 1369 end, page_started, nr_written, 1, 1370 NULL); 1371 if (ret) { 1372 if (!nolock && nocow) 1373 btrfs_end_write_no_snapshoting(root); 1374 if (nocow) 1375 btrfs_dec_nocow_writers(fs_info, 1376 disk_bytenr); 1377 goto error; 1378 } 1379 cow_start = (u64)-1; 1380 } 1381 1382 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1383 u64 orig_start = found_key.offset - extent_offset; 1384 1385 em = create_io_em(inode, cur_offset, num_bytes, 1386 orig_start, 1387 disk_bytenr, /* block_start */ 1388 num_bytes, /* block_len */ 1389 disk_num_bytes, /* orig_block_len */ 1390 ram_bytes, BTRFS_COMPRESS_NONE, 1391 BTRFS_ORDERED_PREALLOC); 1392 if (IS_ERR(em)) { 1393 if (!nolock && nocow) 1394 btrfs_end_write_no_snapshoting(root); 1395 if (nocow) 1396 btrfs_dec_nocow_writers(fs_info, 1397 disk_bytenr); 1398 ret = PTR_ERR(em); 1399 goto error; 1400 } 1401 free_extent_map(em); 1402 } 1403 1404 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1405 type = BTRFS_ORDERED_PREALLOC; 1406 } else { 1407 type = BTRFS_ORDERED_NOCOW; 1408 } 1409 1410 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1411 num_bytes, num_bytes, type); 1412 if (nocow) 1413 btrfs_dec_nocow_writers(fs_info, disk_bytenr); 1414 BUG_ON(ret); /* -ENOMEM */ 1415 1416 if (root->root_key.objectid == 1417 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1418 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1419 num_bytes); 1420 if (ret) { 1421 if (!nolock && nocow) 1422 btrfs_end_write_no_snapshoting(root); 1423 goto error; 1424 } 1425 } 1426 1427 extent_clear_unlock_delalloc(inode, cur_offset, 1428 cur_offset + num_bytes - 1, end, 1429 locked_page, EXTENT_LOCKED | 1430 EXTENT_DELALLOC | 1431 EXTENT_CLEAR_DATA_RESV, 1432 PAGE_UNLOCK | PAGE_SET_PRIVATE2); 1433 1434 if (!nolock && nocow) 1435 btrfs_end_write_no_snapshoting(root); 1436 cur_offset = extent_end; 1437 if (cur_offset > end) 1438 break; 1439 } 1440 btrfs_release_path(path); 1441 1442 if (cur_offset <= end && cow_start == (u64)-1) { 1443 cow_start = cur_offset; 1444 cur_offset = end; 1445 } 1446 1447 if (cow_start != (u64)-1) { 1448 ret = cow_file_range(inode, locked_page, cow_start, end, end, 1449 page_started, nr_written, 1, NULL); 1450 if (ret) 1451 goto error; 1452 } 1453 1454 error: 1455 if (ret && cur_offset < end) 1456 extent_clear_unlock_delalloc(inode, cur_offset, end, end, 1457 locked_page, EXTENT_LOCKED | 1458 EXTENT_DELALLOC | EXTENT_DEFRAG | 1459 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | 1460 PAGE_CLEAR_DIRTY | 1461 PAGE_SET_WRITEBACK | 1462 PAGE_END_WRITEBACK); 1463 btrfs_free_path(path); 1464 return ret; 1465 } 1466 1467 static inline int need_force_cow(struct inode *inode, u64 start, u64 end) 1468 { 1469 1470 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 1471 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) 1472 return 0; 1473 1474 /* 1475 * @defrag_bytes is a hint value, no spinlock held here, 1476 * if is not zero, it means the file is defragging. 1477 * Force cow if given extent needs to be defragged. 1478 */ 1479 if (BTRFS_I(inode)->defrag_bytes && 1480 test_range_bit(&BTRFS_I(inode)->io_tree, start, end, 1481 EXTENT_DEFRAG, 0, NULL)) 1482 return 1; 1483 1484 return 0; 1485 } 1486 1487 /* 1488 * extent_io.c call back to do delayed allocation processing 1489 */ 1490 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1491 u64 start, u64 end, int *page_started, 1492 unsigned long *nr_written) 1493 { 1494 int ret; 1495 int force_cow = need_force_cow(inode, start, end); 1496 1497 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) { 1498 ret = run_delalloc_nocow(inode, locked_page, start, end, 1499 page_started, 1, nr_written); 1500 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) { 1501 ret = run_delalloc_nocow(inode, locked_page, start, end, 1502 page_started, 0, nr_written); 1503 } else if (!inode_need_compress(inode)) { 1504 ret = cow_file_range(inode, locked_page, start, end, end, 1505 page_started, nr_written, 1, NULL); 1506 } else { 1507 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1508 &BTRFS_I(inode)->runtime_flags); 1509 ret = cow_file_range_async(inode, locked_page, start, end, 1510 page_started, nr_written); 1511 } 1512 return ret; 1513 } 1514 1515 static void btrfs_split_extent_hook(struct inode *inode, 1516 struct extent_state *orig, u64 split) 1517 { 1518 u64 size; 1519 1520 /* not delalloc, ignore it */ 1521 if (!(orig->state & EXTENT_DELALLOC)) 1522 return; 1523 1524 size = orig->end - orig->start + 1; 1525 if (size > BTRFS_MAX_EXTENT_SIZE) { 1526 u32 num_extents; 1527 u64 new_size; 1528 1529 /* 1530 * See the explanation in btrfs_merge_extent_hook, the same 1531 * applies here, just in reverse. 1532 */ 1533 new_size = orig->end - split + 1; 1534 num_extents = count_max_extents(new_size); 1535 new_size = split - orig->start; 1536 num_extents += count_max_extents(new_size); 1537 if (count_max_extents(size) >= num_extents) 1538 return; 1539 } 1540 1541 spin_lock(&BTRFS_I(inode)->lock); 1542 BTRFS_I(inode)->outstanding_extents++; 1543 spin_unlock(&BTRFS_I(inode)->lock); 1544 } 1545 1546 /* 1547 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1548 * extents so we can keep track of new extents that are just merged onto old 1549 * extents, such as when we are doing sequential writes, so we can properly 1550 * account for the metadata space we'll need. 1551 */ 1552 static void btrfs_merge_extent_hook(struct inode *inode, 1553 struct extent_state *new, 1554 struct extent_state *other) 1555 { 1556 u64 new_size, old_size; 1557 u32 num_extents; 1558 1559 /* not delalloc, ignore it */ 1560 if (!(other->state & EXTENT_DELALLOC)) 1561 return; 1562 1563 if (new->start > other->start) 1564 new_size = new->end - other->start + 1; 1565 else 1566 new_size = other->end - new->start + 1; 1567 1568 /* we're not bigger than the max, unreserve the space and go */ 1569 if (new_size <= BTRFS_MAX_EXTENT_SIZE) { 1570 spin_lock(&BTRFS_I(inode)->lock); 1571 BTRFS_I(inode)->outstanding_extents--; 1572 spin_unlock(&BTRFS_I(inode)->lock); 1573 return; 1574 } 1575 1576 /* 1577 * We have to add up either side to figure out how many extents were 1578 * accounted for before we merged into one big extent. If the number of 1579 * extents we accounted for is <= the amount we need for the new range 1580 * then we can return, otherwise drop. Think of it like this 1581 * 1582 * [ 4k][MAX_SIZE] 1583 * 1584 * So we've grown the extent by a MAX_SIZE extent, this would mean we 1585 * need 2 outstanding extents, on one side we have 1 and the other side 1586 * we have 1 so they are == and we can return. But in this case 1587 * 1588 * [MAX_SIZE+4k][MAX_SIZE+4k] 1589 * 1590 * Each range on their own accounts for 2 extents, but merged together 1591 * they are only 3 extents worth of accounting, so we need to drop in 1592 * this case. 1593 */ 1594 old_size = other->end - other->start + 1; 1595 num_extents = count_max_extents(old_size); 1596 old_size = new->end - new->start + 1; 1597 num_extents += count_max_extents(old_size); 1598 if (count_max_extents(new_size) >= num_extents) 1599 return; 1600 1601 spin_lock(&BTRFS_I(inode)->lock); 1602 BTRFS_I(inode)->outstanding_extents--; 1603 spin_unlock(&BTRFS_I(inode)->lock); 1604 } 1605 1606 static void btrfs_add_delalloc_inodes(struct btrfs_root *root, 1607 struct inode *inode) 1608 { 1609 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1610 1611 spin_lock(&root->delalloc_lock); 1612 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1613 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1614 &root->delalloc_inodes); 1615 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1616 &BTRFS_I(inode)->runtime_flags); 1617 root->nr_delalloc_inodes++; 1618 if (root->nr_delalloc_inodes == 1) { 1619 spin_lock(&fs_info->delalloc_root_lock); 1620 BUG_ON(!list_empty(&root->delalloc_root)); 1621 list_add_tail(&root->delalloc_root, 1622 &fs_info->delalloc_roots); 1623 spin_unlock(&fs_info->delalloc_root_lock); 1624 } 1625 } 1626 spin_unlock(&root->delalloc_lock); 1627 } 1628 1629 static void btrfs_del_delalloc_inode(struct btrfs_root *root, 1630 struct btrfs_inode *inode) 1631 { 1632 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); 1633 1634 spin_lock(&root->delalloc_lock); 1635 if (!list_empty(&inode->delalloc_inodes)) { 1636 list_del_init(&inode->delalloc_inodes); 1637 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1638 &inode->runtime_flags); 1639 root->nr_delalloc_inodes--; 1640 if (!root->nr_delalloc_inodes) { 1641 spin_lock(&fs_info->delalloc_root_lock); 1642 BUG_ON(list_empty(&root->delalloc_root)); 1643 list_del_init(&root->delalloc_root); 1644 spin_unlock(&fs_info->delalloc_root_lock); 1645 } 1646 } 1647 spin_unlock(&root->delalloc_lock); 1648 } 1649 1650 /* 1651 * extent_io.c set_bit_hook, used to track delayed allocation 1652 * bytes in this file, and to maintain the list of inodes that 1653 * have pending delalloc work to be done. 1654 */ 1655 static void btrfs_set_bit_hook(struct inode *inode, 1656 struct extent_state *state, unsigned *bits) 1657 { 1658 1659 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1660 1661 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) 1662 WARN_ON(1); 1663 /* 1664 * set_bit and clear bit hooks normally require _irqsave/restore 1665 * but in this case, we are only testing for the DELALLOC 1666 * bit, which is only set or cleared with irqs on 1667 */ 1668 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1669 struct btrfs_root *root = BTRFS_I(inode)->root; 1670 u64 len = state->end + 1 - state->start; 1671 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode)); 1672 1673 if (*bits & EXTENT_FIRST_DELALLOC) { 1674 *bits &= ~EXTENT_FIRST_DELALLOC; 1675 } else { 1676 spin_lock(&BTRFS_I(inode)->lock); 1677 BTRFS_I(inode)->outstanding_extents++; 1678 spin_unlock(&BTRFS_I(inode)->lock); 1679 } 1680 1681 /* For sanity tests */ 1682 if (btrfs_is_testing(fs_info)) 1683 return; 1684 1685 __percpu_counter_add(&fs_info->delalloc_bytes, len, 1686 fs_info->delalloc_batch); 1687 spin_lock(&BTRFS_I(inode)->lock); 1688 BTRFS_I(inode)->delalloc_bytes += len; 1689 if (*bits & EXTENT_DEFRAG) 1690 BTRFS_I(inode)->defrag_bytes += len; 1691 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1692 &BTRFS_I(inode)->runtime_flags)) 1693 btrfs_add_delalloc_inodes(root, inode); 1694 spin_unlock(&BTRFS_I(inode)->lock); 1695 } 1696 } 1697 1698 /* 1699 * extent_io.c clear_bit_hook, see set_bit_hook for why 1700 */ 1701 static void btrfs_clear_bit_hook(struct btrfs_inode *inode, 1702 struct extent_state *state, 1703 unsigned *bits) 1704 { 1705 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); 1706 u64 len = state->end + 1 - state->start; 1707 u32 num_extents = count_max_extents(len); 1708 1709 spin_lock(&inode->lock); 1710 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) 1711 inode->defrag_bytes -= len; 1712 spin_unlock(&inode->lock); 1713 1714 /* 1715 * set_bit and clear bit hooks normally require _irqsave/restore 1716 * but in this case, we are only testing for the DELALLOC 1717 * bit, which is only set or cleared with irqs on 1718 */ 1719 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1720 struct btrfs_root *root = inode->root; 1721 bool do_list = !btrfs_is_free_space_inode(inode); 1722 1723 if (*bits & EXTENT_FIRST_DELALLOC) { 1724 *bits &= ~EXTENT_FIRST_DELALLOC; 1725 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1726 spin_lock(&inode->lock); 1727 inode->outstanding_extents -= num_extents; 1728 spin_unlock(&inode->lock); 1729 } 1730 1731 /* 1732 * We don't reserve metadata space for space cache inodes so we 1733 * don't need to call dellalloc_release_metadata if there is an 1734 * error. 1735 */ 1736 if (*bits & EXTENT_DO_ACCOUNTING && 1737 root != fs_info->tree_root) 1738 btrfs_delalloc_release_metadata(inode, len); 1739 1740 /* For sanity tests. */ 1741 if (btrfs_is_testing(fs_info)) 1742 return; 1743 1744 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1745 && do_list && !(state->state & EXTENT_NORESERVE) 1746 && (*bits & (EXTENT_DO_ACCOUNTING | 1747 EXTENT_CLEAR_DATA_RESV))) 1748 btrfs_free_reserved_data_space_noquota( 1749 &inode->vfs_inode, 1750 state->start, len); 1751 1752 __percpu_counter_add(&fs_info->delalloc_bytes, -len, 1753 fs_info->delalloc_batch); 1754 spin_lock(&inode->lock); 1755 inode->delalloc_bytes -= len; 1756 if (do_list && inode->delalloc_bytes == 0 && 1757 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1758 &inode->runtime_flags)) 1759 btrfs_del_delalloc_inode(root, inode); 1760 spin_unlock(&inode->lock); 1761 } 1762 } 1763 1764 /* 1765 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1766 * we don't create bios that span stripes or chunks 1767 * 1768 * return 1 if page cannot be merged to bio 1769 * return 0 if page can be merged to bio 1770 * return error otherwise 1771 */ 1772 int btrfs_merge_bio_hook(struct page *page, unsigned long offset, 1773 size_t size, struct bio *bio, 1774 unsigned long bio_flags) 1775 { 1776 struct inode *inode = page->mapping->host; 1777 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1778 u64 logical = (u64)bio->bi_iter.bi_sector << 9; 1779 u64 length = 0; 1780 u64 map_length; 1781 int ret; 1782 1783 if (bio_flags & EXTENT_BIO_COMPRESSED) 1784 return 0; 1785 1786 length = bio->bi_iter.bi_size; 1787 map_length = length; 1788 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length, 1789 NULL, 0); 1790 if (ret < 0) 1791 return ret; 1792 if (map_length < length + size) 1793 return 1; 1794 return 0; 1795 } 1796 1797 /* 1798 * in order to insert checksums into the metadata in large chunks, 1799 * we wait until bio submission time. All the pages in the bio are 1800 * checksummed and sums are attached onto the ordered extent record. 1801 * 1802 * At IO completion time the cums attached on the ordered extent record 1803 * are inserted into the btree 1804 */ 1805 static int __btrfs_submit_bio_start(struct inode *inode, struct bio *bio, 1806 int mirror_num, unsigned long bio_flags, 1807 u64 bio_offset) 1808 { 1809 int ret = 0; 1810 1811 ret = btrfs_csum_one_bio(inode, bio, 0, 0); 1812 BUG_ON(ret); /* -ENOMEM */ 1813 return 0; 1814 } 1815 1816 /* 1817 * in order to insert checksums into the metadata in large chunks, 1818 * we wait until bio submission time. All the pages in the bio are 1819 * checksummed and sums are attached onto the ordered extent record. 1820 * 1821 * At IO completion time the cums attached on the ordered extent record 1822 * are inserted into the btree 1823 */ 1824 static int __btrfs_submit_bio_done(struct inode *inode, struct bio *bio, 1825 int mirror_num, unsigned long bio_flags, 1826 u64 bio_offset) 1827 { 1828 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1829 int ret; 1830 1831 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1); 1832 if (ret) { 1833 bio->bi_error = ret; 1834 bio_endio(bio); 1835 } 1836 return ret; 1837 } 1838 1839 /* 1840 * extent_io.c submission hook. This does the right thing for csum calculation 1841 * on write, or reading the csums from the tree before a read 1842 */ 1843 static int btrfs_submit_bio_hook(struct inode *inode, struct bio *bio, 1844 int mirror_num, unsigned long bio_flags, 1845 u64 bio_offset) 1846 { 1847 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1848 struct btrfs_root *root = BTRFS_I(inode)->root; 1849 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA; 1850 int ret = 0; 1851 int skip_sum; 1852 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1853 1854 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1855 1856 if (btrfs_is_free_space_inode(BTRFS_I(inode))) 1857 metadata = BTRFS_WQ_ENDIO_FREE_SPACE; 1858 1859 if (bio_op(bio) != REQ_OP_WRITE) { 1860 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata); 1861 if (ret) 1862 goto out; 1863 1864 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1865 ret = btrfs_submit_compressed_read(inode, bio, 1866 mirror_num, 1867 bio_flags); 1868 goto out; 1869 } else if (!skip_sum) { 1870 ret = btrfs_lookup_bio_sums(inode, bio, NULL); 1871 if (ret) 1872 goto out; 1873 } 1874 goto mapit; 1875 } else if (async && !skip_sum) { 1876 /* csum items have already been cloned */ 1877 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1878 goto mapit; 1879 /* we're doing a write, do the async checksumming */ 1880 ret = btrfs_wq_submit_bio(fs_info, inode, bio, mirror_num, 1881 bio_flags, bio_offset, 1882 __btrfs_submit_bio_start, 1883 __btrfs_submit_bio_done); 1884 goto out; 1885 } else if (!skip_sum) { 1886 ret = btrfs_csum_one_bio(inode, bio, 0, 0); 1887 if (ret) 1888 goto out; 1889 } 1890 1891 mapit: 1892 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0); 1893 1894 out: 1895 if (ret < 0) { 1896 bio->bi_error = ret; 1897 bio_endio(bio); 1898 } 1899 return ret; 1900 } 1901 1902 /* 1903 * given a list of ordered sums record them in the inode. This happens 1904 * at IO completion time based on sums calculated at bio submission time. 1905 */ 1906 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1907 struct inode *inode, struct list_head *list) 1908 { 1909 struct btrfs_ordered_sum *sum; 1910 1911 list_for_each_entry(sum, list, list) { 1912 trans->adding_csums = 1; 1913 btrfs_csum_file_blocks(trans, 1914 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1915 trans->adding_csums = 0; 1916 } 1917 return 0; 1918 } 1919 1920 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1921 struct extent_state **cached_state, int dedupe) 1922 { 1923 WARN_ON((end & (PAGE_SIZE - 1)) == 0); 1924 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1925 cached_state); 1926 } 1927 1928 /* see btrfs_writepage_start_hook for details on why this is required */ 1929 struct btrfs_writepage_fixup { 1930 struct page *page; 1931 struct btrfs_work work; 1932 }; 1933 1934 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1935 { 1936 struct btrfs_writepage_fixup *fixup; 1937 struct btrfs_ordered_extent *ordered; 1938 struct extent_state *cached_state = NULL; 1939 struct page *page; 1940 struct inode *inode; 1941 u64 page_start; 1942 u64 page_end; 1943 int ret; 1944 1945 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1946 page = fixup->page; 1947 again: 1948 lock_page(page); 1949 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1950 ClearPageChecked(page); 1951 goto out_page; 1952 } 1953 1954 inode = page->mapping->host; 1955 page_start = page_offset(page); 1956 page_end = page_offset(page) + PAGE_SIZE - 1; 1957 1958 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 1959 &cached_state); 1960 1961 /* already ordered? We're done */ 1962 if (PagePrivate2(page)) 1963 goto out; 1964 1965 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start, 1966 PAGE_SIZE); 1967 if (ordered) { 1968 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 1969 page_end, &cached_state, GFP_NOFS); 1970 unlock_page(page); 1971 btrfs_start_ordered_extent(inode, ordered, 1); 1972 btrfs_put_ordered_extent(ordered); 1973 goto again; 1974 } 1975 1976 ret = btrfs_delalloc_reserve_space(inode, page_start, 1977 PAGE_SIZE); 1978 if (ret) { 1979 mapping_set_error(page->mapping, ret); 1980 end_extent_writepage(page, ret, page_start, page_end); 1981 ClearPageChecked(page); 1982 goto out; 1983 } 1984 1985 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state, 1986 0); 1987 ClearPageChecked(page); 1988 set_page_dirty(page); 1989 out: 1990 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 1991 &cached_state, GFP_NOFS); 1992 out_page: 1993 unlock_page(page); 1994 put_page(page); 1995 kfree(fixup); 1996 } 1997 1998 /* 1999 * There are a few paths in the higher layers of the kernel that directly 2000 * set the page dirty bit without asking the filesystem if it is a 2001 * good idea. This causes problems because we want to make sure COW 2002 * properly happens and the data=ordered rules are followed. 2003 * 2004 * In our case any range that doesn't have the ORDERED bit set 2005 * hasn't been properly setup for IO. We kick off an async process 2006 * to fix it up. The async helper will wait for ordered extents, set 2007 * the delalloc bit and make it safe to write the page. 2008 */ 2009 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 2010 { 2011 struct inode *inode = page->mapping->host; 2012 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2013 struct btrfs_writepage_fixup *fixup; 2014 2015 /* this page is properly in the ordered list */ 2016 if (TestClearPagePrivate2(page)) 2017 return 0; 2018 2019 if (PageChecked(page)) 2020 return -EAGAIN; 2021 2022 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 2023 if (!fixup) 2024 return -EAGAIN; 2025 2026 SetPageChecked(page); 2027 get_page(page); 2028 btrfs_init_work(&fixup->work, btrfs_fixup_helper, 2029 btrfs_writepage_fixup_worker, NULL, NULL); 2030 fixup->page = page; 2031 btrfs_queue_work(fs_info->fixup_workers, &fixup->work); 2032 return -EBUSY; 2033 } 2034 2035 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 2036 struct inode *inode, u64 file_pos, 2037 u64 disk_bytenr, u64 disk_num_bytes, 2038 u64 num_bytes, u64 ram_bytes, 2039 u8 compression, u8 encryption, 2040 u16 other_encoding, int extent_type) 2041 { 2042 struct btrfs_root *root = BTRFS_I(inode)->root; 2043 struct btrfs_file_extent_item *fi; 2044 struct btrfs_path *path; 2045 struct extent_buffer *leaf; 2046 struct btrfs_key ins; 2047 int extent_inserted = 0; 2048 int ret; 2049 2050 path = btrfs_alloc_path(); 2051 if (!path) 2052 return -ENOMEM; 2053 2054 /* 2055 * we may be replacing one extent in the tree with another. 2056 * The new extent is pinned in the extent map, and we don't want 2057 * to drop it from the cache until it is completely in the btree. 2058 * 2059 * So, tell btrfs_drop_extents to leave this extent in the cache. 2060 * the caller is expected to unpin it and allow it to be merged 2061 * with the others. 2062 */ 2063 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, 2064 file_pos + num_bytes, NULL, 0, 2065 1, sizeof(*fi), &extent_inserted); 2066 if (ret) 2067 goto out; 2068 2069 if (!extent_inserted) { 2070 ins.objectid = btrfs_ino(BTRFS_I(inode)); 2071 ins.offset = file_pos; 2072 ins.type = BTRFS_EXTENT_DATA_KEY; 2073 2074 path->leave_spinning = 1; 2075 ret = btrfs_insert_empty_item(trans, root, path, &ins, 2076 sizeof(*fi)); 2077 if (ret) 2078 goto out; 2079 } 2080 leaf = path->nodes[0]; 2081 fi = btrfs_item_ptr(leaf, path->slots[0], 2082 struct btrfs_file_extent_item); 2083 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 2084 btrfs_set_file_extent_type(leaf, fi, extent_type); 2085 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 2086 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 2087 btrfs_set_file_extent_offset(leaf, fi, 0); 2088 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 2089 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 2090 btrfs_set_file_extent_compression(leaf, fi, compression); 2091 btrfs_set_file_extent_encryption(leaf, fi, encryption); 2092 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 2093 2094 btrfs_mark_buffer_dirty(leaf); 2095 btrfs_release_path(path); 2096 2097 inode_add_bytes(inode, num_bytes); 2098 2099 ins.objectid = disk_bytenr; 2100 ins.offset = disk_num_bytes; 2101 ins.type = BTRFS_EXTENT_ITEM_KEY; 2102 ret = btrfs_alloc_reserved_file_extent(trans, root->root_key.objectid, 2103 btrfs_ino(BTRFS_I(inode)), file_pos, ram_bytes, &ins); 2104 /* 2105 * Release the reserved range from inode dirty range map, as it is 2106 * already moved into delayed_ref_head 2107 */ 2108 btrfs_qgroup_release_data(inode, file_pos, ram_bytes); 2109 out: 2110 btrfs_free_path(path); 2111 2112 return ret; 2113 } 2114 2115 /* snapshot-aware defrag */ 2116 struct sa_defrag_extent_backref { 2117 struct rb_node node; 2118 struct old_sa_defrag_extent *old; 2119 u64 root_id; 2120 u64 inum; 2121 u64 file_pos; 2122 u64 extent_offset; 2123 u64 num_bytes; 2124 u64 generation; 2125 }; 2126 2127 struct old_sa_defrag_extent { 2128 struct list_head list; 2129 struct new_sa_defrag_extent *new; 2130 2131 u64 extent_offset; 2132 u64 bytenr; 2133 u64 offset; 2134 u64 len; 2135 int count; 2136 }; 2137 2138 struct new_sa_defrag_extent { 2139 struct rb_root root; 2140 struct list_head head; 2141 struct btrfs_path *path; 2142 struct inode *inode; 2143 u64 file_pos; 2144 u64 len; 2145 u64 bytenr; 2146 u64 disk_len; 2147 u8 compress_type; 2148 }; 2149 2150 static int backref_comp(struct sa_defrag_extent_backref *b1, 2151 struct sa_defrag_extent_backref *b2) 2152 { 2153 if (b1->root_id < b2->root_id) 2154 return -1; 2155 else if (b1->root_id > b2->root_id) 2156 return 1; 2157 2158 if (b1->inum < b2->inum) 2159 return -1; 2160 else if (b1->inum > b2->inum) 2161 return 1; 2162 2163 if (b1->file_pos < b2->file_pos) 2164 return -1; 2165 else if (b1->file_pos > b2->file_pos) 2166 return 1; 2167 2168 /* 2169 * [------------------------------] ===> (a range of space) 2170 * |<--->| |<---->| =============> (fs/file tree A) 2171 * |<---------------------------->| ===> (fs/file tree B) 2172 * 2173 * A range of space can refer to two file extents in one tree while 2174 * refer to only one file extent in another tree. 2175 * 2176 * So we may process a disk offset more than one time(two extents in A) 2177 * and locate at the same extent(one extent in B), then insert two same 2178 * backrefs(both refer to the extent in B). 2179 */ 2180 return 0; 2181 } 2182 2183 static void backref_insert(struct rb_root *root, 2184 struct sa_defrag_extent_backref *backref) 2185 { 2186 struct rb_node **p = &root->rb_node; 2187 struct rb_node *parent = NULL; 2188 struct sa_defrag_extent_backref *entry; 2189 int ret; 2190 2191 while (*p) { 2192 parent = *p; 2193 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2194 2195 ret = backref_comp(backref, entry); 2196 if (ret < 0) 2197 p = &(*p)->rb_left; 2198 else 2199 p = &(*p)->rb_right; 2200 } 2201 2202 rb_link_node(&backref->node, parent, p); 2203 rb_insert_color(&backref->node, root); 2204 } 2205 2206 /* 2207 * Note the backref might has changed, and in this case we just return 0. 2208 */ 2209 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2210 void *ctx) 2211 { 2212 struct btrfs_file_extent_item *extent; 2213 struct old_sa_defrag_extent *old = ctx; 2214 struct new_sa_defrag_extent *new = old->new; 2215 struct btrfs_path *path = new->path; 2216 struct btrfs_key key; 2217 struct btrfs_root *root; 2218 struct sa_defrag_extent_backref *backref; 2219 struct extent_buffer *leaf; 2220 struct inode *inode = new->inode; 2221 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2222 int slot; 2223 int ret; 2224 u64 extent_offset; 2225 u64 num_bytes; 2226 2227 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2228 inum == btrfs_ino(BTRFS_I(inode))) 2229 return 0; 2230 2231 key.objectid = root_id; 2232 key.type = BTRFS_ROOT_ITEM_KEY; 2233 key.offset = (u64)-1; 2234 2235 root = btrfs_read_fs_root_no_name(fs_info, &key); 2236 if (IS_ERR(root)) { 2237 if (PTR_ERR(root) == -ENOENT) 2238 return 0; 2239 WARN_ON(1); 2240 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu", 2241 inum, offset, root_id); 2242 return PTR_ERR(root); 2243 } 2244 2245 key.objectid = inum; 2246 key.type = BTRFS_EXTENT_DATA_KEY; 2247 if (offset > (u64)-1 << 32) 2248 key.offset = 0; 2249 else 2250 key.offset = offset; 2251 2252 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2253 if (WARN_ON(ret < 0)) 2254 return ret; 2255 ret = 0; 2256 2257 while (1) { 2258 cond_resched(); 2259 2260 leaf = path->nodes[0]; 2261 slot = path->slots[0]; 2262 2263 if (slot >= btrfs_header_nritems(leaf)) { 2264 ret = btrfs_next_leaf(root, path); 2265 if (ret < 0) { 2266 goto out; 2267 } else if (ret > 0) { 2268 ret = 0; 2269 goto out; 2270 } 2271 continue; 2272 } 2273 2274 path->slots[0]++; 2275 2276 btrfs_item_key_to_cpu(leaf, &key, slot); 2277 2278 if (key.objectid > inum) 2279 goto out; 2280 2281 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2282 continue; 2283 2284 extent = btrfs_item_ptr(leaf, slot, 2285 struct btrfs_file_extent_item); 2286 2287 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2288 continue; 2289 2290 /* 2291 * 'offset' refers to the exact key.offset, 2292 * NOT the 'offset' field in btrfs_extent_data_ref, ie. 2293 * (key.offset - extent_offset). 2294 */ 2295 if (key.offset != offset) 2296 continue; 2297 2298 extent_offset = btrfs_file_extent_offset(leaf, extent); 2299 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2300 2301 if (extent_offset >= old->extent_offset + old->offset + 2302 old->len || extent_offset + num_bytes <= 2303 old->extent_offset + old->offset) 2304 continue; 2305 break; 2306 } 2307 2308 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2309 if (!backref) { 2310 ret = -ENOENT; 2311 goto out; 2312 } 2313 2314 backref->root_id = root_id; 2315 backref->inum = inum; 2316 backref->file_pos = offset; 2317 backref->num_bytes = num_bytes; 2318 backref->extent_offset = extent_offset; 2319 backref->generation = btrfs_file_extent_generation(leaf, extent); 2320 backref->old = old; 2321 backref_insert(&new->root, backref); 2322 old->count++; 2323 out: 2324 btrfs_release_path(path); 2325 WARN_ON(ret); 2326 return ret; 2327 } 2328 2329 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2330 struct new_sa_defrag_extent *new) 2331 { 2332 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb); 2333 struct old_sa_defrag_extent *old, *tmp; 2334 int ret; 2335 2336 new->path = path; 2337 2338 list_for_each_entry_safe(old, tmp, &new->head, list) { 2339 ret = iterate_inodes_from_logical(old->bytenr + 2340 old->extent_offset, fs_info, 2341 path, record_one_backref, 2342 old); 2343 if (ret < 0 && ret != -ENOENT) 2344 return false; 2345 2346 /* no backref to be processed for this extent */ 2347 if (!old->count) { 2348 list_del(&old->list); 2349 kfree(old); 2350 } 2351 } 2352 2353 if (list_empty(&new->head)) 2354 return false; 2355 2356 return true; 2357 } 2358 2359 static int relink_is_mergable(struct extent_buffer *leaf, 2360 struct btrfs_file_extent_item *fi, 2361 struct new_sa_defrag_extent *new) 2362 { 2363 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) 2364 return 0; 2365 2366 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2367 return 0; 2368 2369 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) 2370 return 0; 2371 2372 if (btrfs_file_extent_encryption(leaf, fi) || 2373 btrfs_file_extent_other_encoding(leaf, fi)) 2374 return 0; 2375 2376 return 1; 2377 } 2378 2379 /* 2380 * Note the backref might has changed, and in this case we just return 0. 2381 */ 2382 static noinline int relink_extent_backref(struct btrfs_path *path, 2383 struct sa_defrag_extent_backref *prev, 2384 struct sa_defrag_extent_backref *backref) 2385 { 2386 struct btrfs_file_extent_item *extent; 2387 struct btrfs_file_extent_item *item; 2388 struct btrfs_ordered_extent *ordered; 2389 struct btrfs_trans_handle *trans; 2390 struct btrfs_root *root; 2391 struct btrfs_key key; 2392 struct extent_buffer *leaf; 2393 struct old_sa_defrag_extent *old = backref->old; 2394 struct new_sa_defrag_extent *new = old->new; 2395 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb); 2396 struct inode *inode; 2397 struct extent_state *cached = NULL; 2398 int ret = 0; 2399 u64 start; 2400 u64 len; 2401 u64 lock_start; 2402 u64 lock_end; 2403 bool merge = false; 2404 int index; 2405 2406 if (prev && prev->root_id == backref->root_id && 2407 prev->inum == backref->inum && 2408 prev->file_pos + prev->num_bytes == backref->file_pos) 2409 merge = true; 2410 2411 /* step 1: get root */ 2412 key.objectid = backref->root_id; 2413 key.type = BTRFS_ROOT_ITEM_KEY; 2414 key.offset = (u64)-1; 2415 2416 index = srcu_read_lock(&fs_info->subvol_srcu); 2417 2418 root = btrfs_read_fs_root_no_name(fs_info, &key); 2419 if (IS_ERR(root)) { 2420 srcu_read_unlock(&fs_info->subvol_srcu, index); 2421 if (PTR_ERR(root) == -ENOENT) 2422 return 0; 2423 return PTR_ERR(root); 2424 } 2425 2426 if (btrfs_root_readonly(root)) { 2427 srcu_read_unlock(&fs_info->subvol_srcu, index); 2428 return 0; 2429 } 2430 2431 /* step 2: get inode */ 2432 key.objectid = backref->inum; 2433 key.type = BTRFS_INODE_ITEM_KEY; 2434 key.offset = 0; 2435 2436 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2437 if (IS_ERR(inode)) { 2438 srcu_read_unlock(&fs_info->subvol_srcu, index); 2439 return 0; 2440 } 2441 2442 srcu_read_unlock(&fs_info->subvol_srcu, index); 2443 2444 /* step 3: relink backref */ 2445 lock_start = backref->file_pos; 2446 lock_end = backref->file_pos + backref->num_bytes - 1; 2447 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2448 &cached); 2449 2450 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2451 if (ordered) { 2452 btrfs_put_ordered_extent(ordered); 2453 goto out_unlock; 2454 } 2455 2456 trans = btrfs_join_transaction(root); 2457 if (IS_ERR(trans)) { 2458 ret = PTR_ERR(trans); 2459 goto out_unlock; 2460 } 2461 2462 key.objectid = backref->inum; 2463 key.type = BTRFS_EXTENT_DATA_KEY; 2464 key.offset = backref->file_pos; 2465 2466 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2467 if (ret < 0) { 2468 goto out_free_path; 2469 } else if (ret > 0) { 2470 ret = 0; 2471 goto out_free_path; 2472 } 2473 2474 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2475 struct btrfs_file_extent_item); 2476 2477 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2478 backref->generation) 2479 goto out_free_path; 2480 2481 btrfs_release_path(path); 2482 2483 start = backref->file_pos; 2484 if (backref->extent_offset < old->extent_offset + old->offset) 2485 start += old->extent_offset + old->offset - 2486 backref->extent_offset; 2487 2488 len = min(backref->extent_offset + backref->num_bytes, 2489 old->extent_offset + old->offset + old->len); 2490 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2491 2492 ret = btrfs_drop_extents(trans, root, inode, start, 2493 start + len, 1); 2494 if (ret) 2495 goto out_free_path; 2496 again: 2497 key.objectid = btrfs_ino(BTRFS_I(inode)); 2498 key.type = BTRFS_EXTENT_DATA_KEY; 2499 key.offset = start; 2500 2501 path->leave_spinning = 1; 2502 if (merge) { 2503 struct btrfs_file_extent_item *fi; 2504 u64 extent_len; 2505 struct btrfs_key found_key; 2506 2507 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 2508 if (ret < 0) 2509 goto out_free_path; 2510 2511 path->slots[0]--; 2512 leaf = path->nodes[0]; 2513 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2514 2515 fi = btrfs_item_ptr(leaf, path->slots[0], 2516 struct btrfs_file_extent_item); 2517 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2518 2519 if (extent_len + found_key.offset == start && 2520 relink_is_mergable(leaf, fi, new)) { 2521 btrfs_set_file_extent_num_bytes(leaf, fi, 2522 extent_len + len); 2523 btrfs_mark_buffer_dirty(leaf); 2524 inode_add_bytes(inode, len); 2525 2526 ret = 1; 2527 goto out_free_path; 2528 } else { 2529 merge = false; 2530 btrfs_release_path(path); 2531 goto again; 2532 } 2533 } 2534 2535 ret = btrfs_insert_empty_item(trans, root, path, &key, 2536 sizeof(*extent)); 2537 if (ret) { 2538 btrfs_abort_transaction(trans, ret); 2539 goto out_free_path; 2540 } 2541 2542 leaf = path->nodes[0]; 2543 item = btrfs_item_ptr(leaf, path->slots[0], 2544 struct btrfs_file_extent_item); 2545 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2546 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2547 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2548 btrfs_set_file_extent_num_bytes(leaf, item, len); 2549 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2550 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2551 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2552 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2553 btrfs_set_file_extent_encryption(leaf, item, 0); 2554 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2555 2556 btrfs_mark_buffer_dirty(leaf); 2557 inode_add_bytes(inode, len); 2558 btrfs_release_path(path); 2559 2560 ret = btrfs_inc_extent_ref(trans, fs_info, new->bytenr, 2561 new->disk_len, 0, 2562 backref->root_id, backref->inum, 2563 new->file_pos); /* start - extent_offset */ 2564 if (ret) { 2565 btrfs_abort_transaction(trans, ret); 2566 goto out_free_path; 2567 } 2568 2569 ret = 1; 2570 out_free_path: 2571 btrfs_release_path(path); 2572 path->leave_spinning = 0; 2573 btrfs_end_transaction(trans); 2574 out_unlock: 2575 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2576 &cached, GFP_NOFS); 2577 iput(inode); 2578 return ret; 2579 } 2580 2581 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) 2582 { 2583 struct old_sa_defrag_extent *old, *tmp; 2584 2585 if (!new) 2586 return; 2587 2588 list_for_each_entry_safe(old, tmp, &new->head, list) { 2589 kfree(old); 2590 } 2591 kfree(new); 2592 } 2593 2594 static void relink_file_extents(struct new_sa_defrag_extent *new) 2595 { 2596 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb); 2597 struct btrfs_path *path; 2598 struct sa_defrag_extent_backref *backref; 2599 struct sa_defrag_extent_backref *prev = NULL; 2600 struct inode *inode; 2601 struct btrfs_root *root; 2602 struct rb_node *node; 2603 int ret; 2604 2605 inode = new->inode; 2606 root = BTRFS_I(inode)->root; 2607 2608 path = btrfs_alloc_path(); 2609 if (!path) 2610 return; 2611 2612 if (!record_extent_backrefs(path, new)) { 2613 btrfs_free_path(path); 2614 goto out; 2615 } 2616 btrfs_release_path(path); 2617 2618 while (1) { 2619 node = rb_first(&new->root); 2620 if (!node) 2621 break; 2622 rb_erase(node, &new->root); 2623 2624 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2625 2626 ret = relink_extent_backref(path, prev, backref); 2627 WARN_ON(ret < 0); 2628 2629 kfree(prev); 2630 2631 if (ret == 1) 2632 prev = backref; 2633 else 2634 prev = NULL; 2635 cond_resched(); 2636 } 2637 kfree(prev); 2638 2639 btrfs_free_path(path); 2640 out: 2641 free_sa_defrag_extent(new); 2642 2643 atomic_dec(&fs_info->defrag_running); 2644 wake_up(&fs_info->transaction_wait); 2645 } 2646 2647 static struct new_sa_defrag_extent * 2648 record_old_file_extents(struct inode *inode, 2649 struct btrfs_ordered_extent *ordered) 2650 { 2651 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2652 struct btrfs_root *root = BTRFS_I(inode)->root; 2653 struct btrfs_path *path; 2654 struct btrfs_key key; 2655 struct old_sa_defrag_extent *old; 2656 struct new_sa_defrag_extent *new; 2657 int ret; 2658 2659 new = kmalloc(sizeof(*new), GFP_NOFS); 2660 if (!new) 2661 return NULL; 2662 2663 new->inode = inode; 2664 new->file_pos = ordered->file_offset; 2665 new->len = ordered->len; 2666 new->bytenr = ordered->start; 2667 new->disk_len = ordered->disk_len; 2668 new->compress_type = ordered->compress_type; 2669 new->root = RB_ROOT; 2670 INIT_LIST_HEAD(&new->head); 2671 2672 path = btrfs_alloc_path(); 2673 if (!path) 2674 goto out_kfree; 2675 2676 key.objectid = btrfs_ino(BTRFS_I(inode)); 2677 key.type = BTRFS_EXTENT_DATA_KEY; 2678 key.offset = new->file_pos; 2679 2680 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2681 if (ret < 0) 2682 goto out_free_path; 2683 if (ret > 0 && path->slots[0] > 0) 2684 path->slots[0]--; 2685 2686 /* find out all the old extents for the file range */ 2687 while (1) { 2688 struct btrfs_file_extent_item *extent; 2689 struct extent_buffer *l; 2690 int slot; 2691 u64 num_bytes; 2692 u64 offset; 2693 u64 end; 2694 u64 disk_bytenr; 2695 u64 extent_offset; 2696 2697 l = path->nodes[0]; 2698 slot = path->slots[0]; 2699 2700 if (slot >= btrfs_header_nritems(l)) { 2701 ret = btrfs_next_leaf(root, path); 2702 if (ret < 0) 2703 goto out_free_path; 2704 else if (ret > 0) 2705 break; 2706 continue; 2707 } 2708 2709 btrfs_item_key_to_cpu(l, &key, slot); 2710 2711 if (key.objectid != btrfs_ino(BTRFS_I(inode))) 2712 break; 2713 if (key.type != BTRFS_EXTENT_DATA_KEY) 2714 break; 2715 if (key.offset >= new->file_pos + new->len) 2716 break; 2717 2718 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2719 2720 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2721 if (key.offset + num_bytes < new->file_pos) 2722 goto next; 2723 2724 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2725 if (!disk_bytenr) 2726 goto next; 2727 2728 extent_offset = btrfs_file_extent_offset(l, extent); 2729 2730 old = kmalloc(sizeof(*old), GFP_NOFS); 2731 if (!old) 2732 goto out_free_path; 2733 2734 offset = max(new->file_pos, key.offset); 2735 end = min(new->file_pos + new->len, key.offset + num_bytes); 2736 2737 old->bytenr = disk_bytenr; 2738 old->extent_offset = extent_offset; 2739 old->offset = offset - key.offset; 2740 old->len = end - offset; 2741 old->new = new; 2742 old->count = 0; 2743 list_add_tail(&old->list, &new->head); 2744 next: 2745 path->slots[0]++; 2746 cond_resched(); 2747 } 2748 2749 btrfs_free_path(path); 2750 atomic_inc(&fs_info->defrag_running); 2751 2752 return new; 2753 2754 out_free_path: 2755 btrfs_free_path(path); 2756 out_kfree: 2757 free_sa_defrag_extent(new); 2758 return NULL; 2759 } 2760 2761 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info, 2762 u64 start, u64 len) 2763 { 2764 struct btrfs_block_group_cache *cache; 2765 2766 cache = btrfs_lookup_block_group(fs_info, start); 2767 ASSERT(cache); 2768 2769 spin_lock(&cache->lock); 2770 cache->delalloc_bytes -= len; 2771 spin_unlock(&cache->lock); 2772 2773 btrfs_put_block_group(cache); 2774 } 2775 2776 /* as ordered data IO finishes, this gets called so we can finish 2777 * an ordered extent if the range of bytes in the file it covers are 2778 * fully written. 2779 */ 2780 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2781 { 2782 struct inode *inode = ordered_extent->inode; 2783 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2784 struct btrfs_root *root = BTRFS_I(inode)->root; 2785 struct btrfs_trans_handle *trans = NULL; 2786 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2787 struct extent_state *cached_state = NULL; 2788 struct new_sa_defrag_extent *new = NULL; 2789 int compress_type = 0; 2790 int ret = 0; 2791 u64 logical_len = ordered_extent->len; 2792 bool nolock; 2793 bool truncated = false; 2794 2795 nolock = btrfs_is_free_space_inode(BTRFS_I(inode)); 2796 2797 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2798 ret = -EIO; 2799 goto out; 2800 } 2801 2802 btrfs_free_io_failure_record(BTRFS_I(inode), 2803 ordered_extent->file_offset, 2804 ordered_extent->file_offset + 2805 ordered_extent->len - 1); 2806 2807 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { 2808 truncated = true; 2809 logical_len = ordered_extent->truncated_len; 2810 /* Truncated the entire extent, don't bother adding */ 2811 if (!logical_len) 2812 goto out; 2813 } 2814 2815 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2816 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2817 2818 /* 2819 * For mwrite(mmap + memset to write) case, we still reserve 2820 * space for NOCOW range. 2821 * As NOCOW won't cause a new delayed ref, just free the space 2822 */ 2823 btrfs_qgroup_free_data(inode, ordered_extent->file_offset, 2824 ordered_extent->len); 2825 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2826 if (nolock) 2827 trans = btrfs_join_transaction_nolock(root); 2828 else 2829 trans = btrfs_join_transaction(root); 2830 if (IS_ERR(trans)) { 2831 ret = PTR_ERR(trans); 2832 trans = NULL; 2833 goto out; 2834 } 2835 trans->block_rsv = &fs_info->delalloc_block_rsv; 2836 ret = btrfs_update_inode_fallback(trans, root, inode); 2837 if (ret) /* -ENOMEM or corruption */ 2838 btrfs_abort_transaction(trans, ret); 2839 goto out; 2840 } 2841 2842 lock_extent_bits(io_tree, ordered_extent->file_offset, 2843 ordered_extent->file_offset + ordered_extent->len - 1, 2844 &cached_state); 2845 2846 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2847 ordered_extent->file_offset + ordered_extent->len - 1, 2848 EXTENT_DEFRAG, 1, cached_state); 2849 if (ret) { 2850 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2851 if (0 && last_snapshot >= BTRFS_I(inode)->generation) 2852 /* the inode is shared */ 2853 new = record_old_file_extents(inode, ordered_extent); 2854 2855 clear_extent_bit(io_tree, ordered_extent->file_offset, 2856 ordered_extent->file_offset + ordered_extent->len - 1, 2857 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2858 } 2859 2860 if (nolock) 2861 trans = btrfs_join_transaction_nolock(root); 2862 else 2863 trans = btrfs_join_transaction(root); 2864 if (IS_ERR(trans)) { 2865 ret = PTR_ERR(trans); 2866 trans = NULL; 2867 goto out_unlock; 2868 } 2869 2870 trans->block_rsv = &fs_info->delalloc_block_rsv; 2871 2872 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2873 compress_type = ordered_extent->compress_type; 2874 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2875 BUG_ON(compress_type); 2876 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode), 2877 ordered_extent->file_offset, 2878 ordered_extent->file_offset + 2879 logical_len); 2880 } else { 2881 BUG_ON(root == fs_info->tree_root); 2882 ret = insert_reserved_file_extent(trans, inode, 2883 ordered_extent->file_offset, 2884 ordered_extent->start, 2885 ordered_extent->disk_len, 2886 logical_len, logical_len, 2887 compress_type, 0, 0, 2888 BTRFS_FILE_EXTENT_REG); 2889 if (!ret) 2890 btrfs_release_delalloc_bytes(fs_info, 2891 ordered_extent->start, 2892 ordered_extent->disk_len); 2893 } 2894 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2895 ordered_extent->file_offset, ordered_extent->len, 2896 trans->transid); 2897 if (ret < 0) { 2898 btrfs_abort_transaction(trans, ret); 2899 goto out_unlock; 2900 } 2901 2902 add_pending_csums(trans, inode, &ordered_extent->list); 2903 2904 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2905 ret = btrfs_update_inode_fallback(trans, root, inode); 2906 if (ret) { /* -ENOMEM or corruption */ 2907 btrfs_abort_transaction(trans, ret); 2908 goto out_unlock; 2909 } 2910 ret = 0; 2911 out_unlock: 2912 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2913 ordered_extent->file_offset + 2914 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2915 out: 2916 if (root != fs_info->tree_root) 2917 btrfs_delalloc_release_metadata(BTRFS_I(inode), 2918 ordered_extent->len); 2919 if (trans) 2920 btrfs_end_transaction(trans); 2921 2922 if (ret || truncated) { 2923 u64 start, end; 2924 2925 if (truncated) 2926 start = ordered_extent->file_offset + logical_len; 2927 else 2928 start = ordered_extent->file_offset; 2929 end = ordered_extent->file_offset + ordered_extent->len - 1; 2930 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); 2931 2932 /* Drop the cache for the part of the extent we didn't write. */ 2933 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0); 2934 2935 /* 2936 * If the ordered extent had an IOERR or something else went 2937 * wrong we need to return the space for this ordered extent 2938 * back to the allocator. We only free the extent in the 2939 * truncated case if we didn't write out the extent at all. 2940 */ 2941 if ((ret || !logical_len) && 2942 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2943 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2944 btrfs_free_reserved_extent(fs_info, 2945 ordered_extent->start, 2946 ordered_extent->disk_len, 1); 2947 } 2948 2949 2950 /* 2951 * This needs to be done to make sure anybody waiting knows we are done 2952 * updating everything for this ordered extent. 2953 */ 2954 btrfs_remove_ordered_extent(inode, ordered_extent); 2955 2956 /* for snapshot-aware defrag */ 2957 if (new) { 2958 if (ret) { 2959 free_sa_defrag_extent(new); 2960 atomic_dec(&fs_info->defrag_running); 2961 } else { 2962 relink_file_extents(new); 2963 } 2964 } 2965 2966 /* once for us */ 2967 btrfs_put_ordered_extent(ordered_extent); 2968 /* once for the tree */ 2969 btrfs_put_ordered_extent(ordered_extent); 2970 2971 return ret; 2972 } 2973 2974 static void finish_ordered_fn(struct btrfs_work *work) 2975 { 2976 struct btrfs_ordered_extent *ordered_extent; 2977 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 2978 btrfs_finish_ordered_io(ordered_extent); 2979 } 2980 2981 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 2982 struct extent_state *state, int uptodate) 2983 { 2984 struct inode *inode = page->mapping->host; 2985 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2986 struct btrfs_ordered_extent *ordered_extent = NULL; 2987 struct btrfs_workqueue *wq; 2988 btrfs_work_func_t func; 2989 2990 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 2991 2992 ClearPagePrivate2(page); 2993 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 2994 end - start + 1, uptodate)) 2995 return; 2996 2997 if (btrfs_is_free_space_inode(BTRFS_I(inode))) { 2998 wq = fs_info->endio_freespace_worker; 2999 func = btrfs_freespace_write_helper; 3000 } else { 3001 wq = fs_info->endio_write_workers; 3002 func = btrfs_endio_write_helper; 3003 } 3004 3005 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL, 3006 NULL); 3007 btrfs_queue_work(wq, &ordered_extent->work); 3008 } 3009 3010 static int __readpage_endio_check(struct inode *inode, 3011 struct btrfs_io_bio *io_bio, 3012 int icsum, struct page *page, 3013 int pgoff, u64 start, size_t len) 3014 { 3015 char *kaddr; 3016 u32 csum_expected; 3017 u32 csum = ~(u32)0; 3018 3019 csum_expected = *(((u32 *)io_bio->csum) + icsum); 3020 3021 kaddr = kmap_atomic(page); 3022 csum = btrfs_csum_data(kaddr + pgoff, csum, len); 3023 btrfs_csum_final(csum, (u8 *)&csum); 3024 if (csum != csum_expected) 3025 goto zeroit; 3026 3027 kunmap_atomic(kaddr); 3028 return 0; 3029 zeroit: 3030 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected, 3031 io_bio->mirror_num); 3032 memset(kaddr + pgoff, 1, len); 3033 flush_dcache_page(page); 3034 kunmap_atomic(kaddr); 3035 if (csum_expected == 0) 3036 return 0; 3037 return -EIO; 3038 } 3039 3040 /* 3041 * when reads are done, we need to check csums to verify the data is correct 3042 * if there's a match, we allow the bio to finish. If not, the code in 3043 * extent_io.c will try to find good copies for us. 3044 */ 3045 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 3046 u64 phy_offset, struct page *page, 3047 u64 start, u64 end, int mirror) 3048 { 3049 size_t offset = start - page_offset(page); 3050 struct inode *inode = page->mapping->host; 3051 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 3052 struct btrfs_root *root = BTRFS_I(inode)->root; 3053 3054 if (PageChecked(page)) { 3055 ClearPageChecked(page); 3056 return 0; 3057 } 3058 3059 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 3060 return 0; 3061 3062 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 3063 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 3064 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM); 3065 return 0; 3066 } 3067 3068 phy_offset >>= inode->i_sb->s_blocksize_bits; 3069 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset, 3070 start, (size_t)(end - start + 1)); 3071 } 3072 3073 void btrfs_add_delayed_iput(struct inode *inode) 3074 { 3075 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 3076 struct btrfs_inode *binode = BTRFS_I(inode); 3077 3078 if (atomic_add_unless(&inode->i_count, -1, 1)) 3079 return; 3080 3081 spin_lock(&fs_info->delayed_iput_lock); 3082 if (binode->delayed_iput_count == 0) { 3083 ASSERT(list_empty(&binode->delayed_iput)); 3084 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs); 3085 } else { 3086 binode->delayed_iput_count++; 3087 } 3088 spin_unlock(&fs_info->delayed_iput_lock); 3089 } 3090 3091 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info) 3092 { 3093 3094 spin_lock(&fs_info->delayed_iput_lock); 3095 while (!list_empty(&fs_info->delayed_iputs)) { 3096 struct btrfs_inode *inode; 3097 3098 inode = list_first_entry(&fs_info->delayed_iputs, 3099 struct btrfs_inode, delayed_iput); 3100 if (inode->delayed_iput_count) { 3101 inode->delayed_iput_count--; 3102 list_move_tail(&inode->delayed_iput, 3103 &fs_info->delayed_iputs); 3104 } else { 3105 list_del_init(&inode->delayed_iput); 3106 } 3107 spin_unlock(&fs_info->delayed_iput_lock); 3108 iput(&inode->vfs_inode); 3109 spin_lock(&fs_info->delayed_iput_lock); 3110 } 3111 spin_unlock(&fs_info->delayed_iput_lock); 3112 } 3113 3114 /* 3115 * This is called in transaction commit time. If there are no orphan 3116 * files in the subvolume, it removes orphan item and frees block_rsv 3117 * structure. 3118 */ 3119 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 3120 struct btrfs_root *root) 3121 { 3122 struct btrfs_fs_info *fs_info = root->fs_info; 3123 struct btrfs_block_rsv *block_rsv; 3124 int ret; 3125 3126 if (atomic_read(&root->orphan_inodes) || 3127 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 3128 return; 3129 3130 spin_lock(&root->orphan_lock); 3131 if (atomic_read(&root->orphan_inodes)) { 3132 spin_unlock(&root->orphan_lock); 3133 return; 3134 } 3135 3136 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 3137 spin_unlock(&root->orphan_lock); 3138 return; 3139 } 3140 3141 block_rsv = root->orphan_block_rsv; 3142 root->orphan_block_rsv = NULL; 3143 spin_unlock(&root->orphan_lock); 3144 3145 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) && 3146 btrfs_root_refs(&root->root_item) > 0) { 3147 ret = btrfs_del_orphan_item(trans, fs_info->tree_root, 3148 root->root_key.objectid); 3149 if (ret) 3150 btrfs_abort_transaction(trans, ret); 3151 else 3152 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, 3153 &root->state); 3154 } 3155 3156 if (block_rsv) { 3157 WARN_ON(block_rsv->size > 0); 3158 btrfs_free_block_rsv(fs_info, block_rsv); 3159 } 3160 } 3161 3162 /* 3163 * This creates an orphan entry for the given inode in case something goes 3164 * wrong in the middle of an unlink/truncate. 3165 * 3166 * NOTE: caller of this function should reserve 5 units of metadata for 3167 * this function. 3168 */ 3169 int btrfs_orphan_add(struct btrfs_trans_handle *trans, 3170 struct btrfs_inode *inode) 3171 { 3172 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); 3173 struct btrfs_root *root = inode->root; 3174 struct btrfs_block_rsv *block_rsv = NULL; 3175 int reserve = 0; 3176 int insert = 0; 3177 int ret; 3178 3179 if (!root->orphan_block_rsv) { 3180 block_rsv = btrfs_alloc_block_rsv(fs_info, 3181 BTRFS_BLOCK_RSV_TEMP); 3182 if (!block_rsv) 3183 return -ENOMEM; 3184 } 3185 3186 spin_lock(&root->orphan_lock); 3187 if (!root->orphan_block_rsv) { 3188 root->orphan_block_rsv = block_rsv; 3189 } else if (block_rsv) { 3190 btrfs_free_block_rsv(fs_info, block_rsv); 3191 block_rsv = NULL; 3192 } 3193 3194 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3195 &inode->runtime_flags)) { 3196 #if 0 3197 /* 3198 * For proper ENOSPC handling, we should do orphan 3199 * cleanup when mounting. But this introduces backward 3200 * compatibility issue. 3201 */ 3202 if (!xchg(&root->orphan_item_inserted, 1)) 3203 insert = 2; 3204 else 3205 insert = 1; 3206 #endif 3207 insert = 1; 3208 atomic_inc(&root->orphan_inodes); 3209 } 3210 3211 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3212 &inode->runtime_flags)) 3213 reserve = 1; 3214 spin_unlock(&root->orphan_lock); 3215 3216 /* grab metadata reservation from transaction handle */ 3217 if (reserve) { 3218 ret = btrfs_orphan_reserve_metadata(trans, inode); 3219 ASSERT(!ret); 3220 if (ret) { 3221 atomic_dec(&root->orphan_inodes); 3222 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3223 &inode->runtime_flags); 3224 if (insert) 3225 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3226 &inode->runtime_flags); 3227 return ret; 3228 } 3229 } 3230 3231 /* insert an orphan item to track this unlinked/truncated file */ 3232 if (insert >= 1) { 3233 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 3234 if (ret) { 3235 atomic_dec(&root->orphan_inodes); 3236 if (reserve) { 3237 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3238 &inode->runtime_flags); 3239 btrfs_orphan_release_metadata(inode); 3240 } 3241 if (ret != -EEXIST) { 3242 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3243 &inode->runtime_flags); 3244 btrfs_abort_transaction(trans, ret); 3245 return ret; 3246 } 3247 } 3248 ret = 0; 3249 } 3250 3251 /* insert an orphan item to track subvolume contains orphan files */ 3252 if (insert >= 2) { 3253 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root, 3254 root->root_key.objectid); 3255 if (ret && ret != -EEXIST) { 3256 btrfs_abort_transaction(trans, ret); 3257 return ret; 3258 } 3259 } 3260 return 0; 3261 } 3262 3263 /* 3264 * We have done the truncate/delete so we can go ahead and remove the orphan 3265 * item for this particular inode. 3266 */ 3267 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3268 struct btrfs_inode *inode) 3269 { 3270 struct btrfs_root *root = inode->root; 3271 int delete_item = 0; 3272 int release_rsv = 0; 3273 int ret = 0; 3274 3275 spin_lock(&root->orphan_lock); 3276 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3277 &inode->runtime_flags)) 3278 delete_item = 1; 3279 3280 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3281 &inode->runtime_flags)) 3282 release_rsv = 1; 3283 spin_unlock(&root->orphan_lock); 3284 3285 if (delete_item) { 3286 atomic_dec(&root->orphan_inodes); 3287 if (trans) 3288 ret = btrfs_del_orphan_item(trans, root, 3289 btrfs_ino(inode)); 3290 } 3291 3292 if (release_rsv) 3293 btrfs_orphan_release_metadata(inode); 3294 3295 return ret; 3296 } 3297 3298 /* 3299 * this cleans up any orphans that may be left on the list from the last use 3300 * of this root. 3301 */ 3302 int btrfs_orphan_cleanup(struct btrfs_root *root) 3303 { 3304 struct btrfs_fs_info *fs_info = root->fs_info; 3305 struct btrfs_path *path; 3306 struct extent_buffer *leaf; 3307 struct btrfs_key key, found_key; 3308 struct btrfs_trans_handle *trans; 3309 struct inode *inode; 3310 u64 last_objectid = 0; 3311 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3312 3313 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3314 return 0; 3315 3316 path = btrfs_alloc_path(); 3317 if (!path) { 3318 ret = -ENOMEM; 3319 goto out; 3320 } 3321 path->reada = READA_BACK; 3322 3323 key.objectid = BTRFS_ORPHAN_OBJECTID; 3324 key.type = BTRFS_ORPHAN_ITEM_KEY; 3325 key.offset = (u64)-1; 3326 3327 while (1) { 3328 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3329 if (ret < 0) 3330 goto out; 3331 3332 /* 3333 * if ret == 0 means we found what we were searching for, which 3334 * is weird, but possible, so only screw with path if we didn't 3335 * find the key and see if we have stuff that matches 3336 */ 3337 if (ret > 0) { 3338 ret = 0; 3339 if (path->slots[0] == 0) 3340 break; 3341 path->slots[0]--; 3342 } 3343 3344 /* pull out the item */ 3345 leaf = path->nodes[0]; 3346 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3347 3348 /* make sure the item matches what we want */ 3349 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3350 break; 3351 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY) 3352 break; 3353 3354 /* release the path since we're done with it */ 3355 btrfs_release_path(path); 3356 3357 /* 3358 * this is where we are basically btrfs_lookup, without the 3359 * crossing root thing. we store the inode number in the 3360 * offset of the orphan item. 3361 */ 3362 3363 if (found_key.offset == last_objectid) { 3364 btrfs_err(fs_info, 3365 "Error removing orphan entry, stopping orphan cleanup"); 3366 ret = -EINVAL; 3367 goto out; 3368 } 3369 3370 last_objectid = found_key.offset; 3371 3372 found_key.objectid = found_key.offset; 3373 found_key.type = BTRFS_INODE_ITEM_KEY; 3374 found_key.offset = 0; 3375 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL); 3376 ret = PTR_ERR_OR_ZERO(inode); 3377 if (ret && ret != -ENOENT) 3378 goto out; 3379 3380 if (ret == -ENOENT && root == fs_info->tree_root) { 3381 struct btrfs_root *dead_root; 3382 struct btrfs_fs_info *fs_info = root->fs_info; 3383 int is_dead_root = 0; 3384 3385 /* 3386 * this is an orphan in the tree root. Currently these 3387 * could come from 2 sources: 3388 * a) a snapshot deletion in progress 3389 * b) a free space cache inode 3390 * We need to distinguish those two, as the snapshot 3391 * orphan must not get deleted. 3392 * find_dead_roots already ran before us, so if this 3393 * is a snapshot deletion, we should find the root 3394 * in the dead_roots list 3395 */ 3396 spin_lock(&fs_info->trans_lock); 3397 list_for_each_entry(dead_root, &fs_info->dead_roots, 3398 root_list) { 3399 if (dead_root->root_key.objectid == 3400 found_key.objectid) { 3401 is_dead_root = 1; 3402 break; 3403 } 3404 } 3405 spin_unlock(&fs_info->trans_lock); 3406 if (is_dead_root) { 3407 /* prevent this orphan from being found again */ 3408 key.offset = found_key.objectid - 1; 3409 continue; 3410 } 3411 } 3412 /* 3413 * Inode is already gone but the orphan item is still there, 3414 * kill the orphan item. 3415 */ 3416 if (ret == -ENOENT) { 3417 trans = btrfs_start_transaction(root, 1); 3418 if (IS_ERR(trans)) { 3419 ret = PTR_ERR(trans); 3420 goto out; 3421 } 3422 btrfs_debug(fs_info, "auto deleting %Lu", 3423 found_key.objectid); 3424 ret = btrfs_del_orphan_item(trans, root, 3425 found_key.objectid); 3426 btrfs_end_transaction(trans); 3427 if (ret) 3428 goto out; 3429 continue; 3430 } 3431 3432 /* 3433 * add this inode to the orphan list so btrfs_orphan_del does 3434 * the proper thing when we hit it 3435 */ 3436 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3437 &BTRFS_I(inode)->runtime_flags); 3438 atomic_inc(&root->orphan_inodes); 3439 3440 /* if we have links, this was a truncate, lets do that */ 3441 if (inode->i_nlink) { 3442 if (WARN_ON(!S_ISREG(inode->i_mode))) { 3443 iput(inode); 3444 continue; 3445 } 3446 nr_truncate++; 3447 3448 /* 1 for the orphan item deletion. */ 3449 trans = btrfs_start_transaction(root, 1); 3450 if (IS_ERR(trans)) { 3451 iput(inode); 3452 ret = PTR_ERR(trans); 3453 goto out; 3454 } 3455 ret = btrfs_orphan_add(trans, BTRFS_I(inode)); 3456 btrfs_end_transaction(trans); 3457 if (ret) { 3458 iput(inode); 3459 goto out; 3460 } 3461 3462 ret = btrfs_truncate(inode); 3463 if (ret) 3464 btrfs_orphan_del(NULL, BTRFS_I(inode)); 3465 } else { 3466 nr_unlink++; 3467 } 3468 3469 /* this will do delete_inode and everything for us */ 3470 iput(inode); 3471 if (ret) 3472 goto out; 3473 } 3474 /* release the path since we're done with it */ 3475 btrfs_release_path(path); 3476 3477 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3478 3479 if (root->orphan_block_rsv) 3480 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv, 3481 (u64)-1); 3482 3483 if (root->orphan_block_rsv || 3484 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) { 3485 trans = btrfs_join_transaction(root); 3486 if (!IS_ERR(trans)) 3487 btrfs_end_transaction(trans); 3488 } 3489 3490 if (nr_unlink) 3491 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink); 3492 if (nr_truncate) 3493 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate); 3494 3495 out: 3496 if (ret) 3497 btrfs_err(fs_info, "could not do orphan cleanup %d", ret); 3498 btrfs_free_path(path); 3499 return ret; 3500 } 3501 3502 /* 3503 * very simple check to peek ahead in the leaf looking for xattrs. If we 3504 * don't find any xattrs, we know there can't be any acls. 3505 * 3506 * slot is the slot the inode is in, objectid is the objectid of the inode 3507 */ 3508 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3509 int slot, u64 objectid, 3510 int *first_xattr_slot) 3511 { 3512 u32 nritems = btrfs_header_nritems(leaf); 3513 struct btrfs_key found_key; 3514 static u64 xattr_access = 0; 3515 static u64 xattr_default = 0; 3516 int scanned = 0; 3517 3518 if (!xattr_access) { 3519 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS, 3520 strlen(XATTR_NAME_POSIX_ACL_ACCESS)); 3521 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT, 3522 strlen(XATTR_NAME_POSIX_ACL_DEFAULT)); 3523 } 3524 3525 slot++; 3526 *first_xattr_slot = -1; 3527 while (slot < nritems) { 3528 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3529 3530 /* we found a different objectid, there must not be acls */ 3531 if (found_key.objectid != objectid) 3532 return 0; 3533 3534 /* we found an xattr, assume we've got an acl */ 3535 if (found_key.type == BTRFS_XATTR_ITEM_KEY) { 3536 if (*first_xattr_slot == -1) 3537 *first_xattr_slot = slot; 3538 if (found_key.offset == xattr_access || 3539 found_key.offset == xattr_default) 3540 return 1; 3541 } 3542 3543 /* 3544 * we found a key greater than an xattr key, there can't 3545 * be any acls later on 3546 */ 3547 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3548 return 0; 3549 3550 slot++; 3551 scanned++; 3552 3553 /* 3554 * it goes inode, inode backrefs, xattrs, extents, 3555 * so if there are a ton of hard links to an inode there can 3556 * be a lot of backrefs. Don't waste time searching too hard, 3557 * this is just an optimization 3558 */ 3559 if (scanned >= 8) 3560 break; 3561 } 3562 /* we hit the end of the leaf before we found an xattr or 3563 * something larger than an xattr. We have to assume the inode 3564 * has acls 3565 */ 3566 if (*first_xattr_slot == -1) 3567 *first_xattr_slot = slot; 3568 return 1; 3569 } 3570 3571 /* 3572 * read an inode from the btree into the in-memory inode 3573 */ 3574 static int btrfs_read_locked_inode(struct inode *inode) 3575 { 3576 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 3577 struct btrfs_path *path; 3578 struct extent_buffer *leaf; 3579 struct btrfs_inode_item *inode_item; 3580 struct btrfs_root *root = BTRFS_I(inode)->root; 3581 struct btrfs_key location; 3582 unsigned long ptr; 3583 int maybe_acls; 3584 u32 rdev; 3585 int ret; 3586 bool filled = false; 3587 int first_xattr_slot; 3588 3589 ret = btrfs_fill_inode(inode, &rdev); 3590 if (!ret) 3591 filled = true; 3592 3593 path = btrfs_alloc_path(); 3594 if (!path) { 3595 ret = -ENOMEM; 3596 goto make_bad; 3597 } 3598 3599 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3600 3601 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3602 if (ret) { 3603 if (ret > 0) 3604 ret = -ENOENT; 3605 goto make_bad; 3606 } 3607 3608 leaf = path->nodes[0]; 3609 3610 if (filled) 3611 goto cache_index; 3612 3613 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3614 struct btrfs_inode_item); 3615 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3616 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3617 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3618 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3619 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item)); 3620 3621 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime); 3622 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime); 3623 3624 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime); 3625 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime); 3626 3627 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime); 3628 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime); 3629 3630 BTRFS_I(inode)->i_otime.tv_sec = 3631 btrfs_timespec_sec(leaf, &inode_item->otime); 3632 BTRFS_I(inode)->i_otime.tv_nsec = 3633 btrfs_timespec_nsec(leaf, &inode_item->otime); 3634 3635 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3636 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3637 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3638 3639 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3640 inode->i_generation = BTRFS_I(inode)->generation; 3641 inode->i_rdev = 0; 3642 rdev = btrfs_inode_rdev(leaf, inode_item); 3643 3644 BTRFS_I(inode)->index_cnt = (u64)-1; 3645 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3646 3647 cache_index: 3648 /* 3649 * If we were modified in the current generation and evicted from memory 3650 * and then re-read we need to do a full sync since we don't have any 3651 * idea about which extents were modified before we were evicted from 3652 * cache. 3653 * 3654 * This is required for both inode re-read from disk and delayed inode 3655 * in delayed_nodes_tree. 3656 */ 3657 if (BTRFS_I(inode)->last_trans == fs_info->generation) 3658 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3659 &BTRFS_I(inode)->runtime_flags); 3660 3661 /* 3662 * We don't persist the id of the transaction where an unlink operation 3663 * against the inode was last made. So here we assume the inode might 3664 * have been evicted, and therefore the exact value of last_unlink_trans 3665 * lost, and set it to last_trans to avoid metadata inconsistencies 3666 * between the inode and its parent if the inode is fsync'ed and the log 3667 * replayed. For example, in the scenario: 3668 * 3669 * touch mydir/foo 3670 * ln mydir/foo mydir/bar 3671 * sync 3672 * unlink mydir/bar 3673 * echo 2 > /proc/sys/vm/drop_caches # evicts inode 3674 * xfs_io -c fsync mydir/foo 3675 * <power failure> 3676 * mount fs, triggers fsync log replay 3677 * 3678 * We must make sure that when we fsync our inode foo we also log its 3679 * parent inode, otherwise after log replay the parent still has the 3680 * dentry with the "bar" name but our inode foo has a link count of 1 3681 * and doesn't have an inode ref with the name "bar" anymore. 3682 * 3683 * Setting last_unlink_trans to last_trans is a pessimistic approach, 3684 * but it guarantees correctness at the expense of occasional full 3685 * transaction commits on fsync if our inode is a directory, or if our 3686 * inode is not a directory, logging its parent unnecessarily. 3687 */ 3688 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans; 3689 3690 path->slots[0]++; 3691 if (inode->i_nlink != 1 || 3692 path->slots[0] >= btrfs_header_nritems(leaf)) 3693 goto cache_acl; 3694 3695 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); 3696 if (location.objectid != btrfs_ino(BTRFS_I(inode))) 3697 goto cache_acl; 3698 3699 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 3700 if (location.type == BTRFS_INODE_REF_KEY) { 3701 struct btrfs_inode_ref *ref; 3702 3703 ref = (struct btrfs_inode_ref *)ptr; 3704 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); 3705 } else if (location.type == BTRFS_INODE_EXTREF_KEY) { 3706 struct btrfs_inode_extref *extref; 3707 3708 extref = (struct btrfs_inode_extref *)ptr; 3709 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, 3710 extref); 3711 } 3712 cache_acl: 3713 /* 3714 * try to precache a NULL acl entry for files that don't have 3715 * any xattrs or acls 3716 */ 3717 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3718 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot); 3719 if (first_xattr_slot != -1) { 3720 path->slots[0] = first_xattr_slot; 3721 ret = btrfs_load_inode_props(inode, path); 3722 if (ret) 3723 btrfs_err(fs_info, 3724 "error loading props for ino %llu (root %llu): %d", 3725 btrfs_ino(BTRFS_I(inode)), 3726 root->root_key.objectid, ret); 3727 } 3728 btrfs_free_path(path); 3729 3730 if (!maybe_acls) 3731 cache_no_acl(inode); 3732 3733 switch (inode->i_mode & S_IFMT) { 3734 case S_IFREG: 3735 inode->i_mapping->a_ops = &btrfs_aops; 3736 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3737 inode->i_fop = &btrfs_file_operations; 3738 inode->i_op = &btrfs_file_inode_operations; 3739 break; 3740 case S_IFDIR: 3741 inode->i_fop = &btrfs_dir_file_operations; 3742 inode->i_op = &btrfs_dir_inode_operations; 3743 break; 3744 case S_IFLNK: 3745 inode->i_op = &btrfs_symlink_inode_operations; 3746 inode_nohighmem(inode); 3747 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3748 break; 3749 default: 3750 inode->i_op = &btrfs_special_inode_operations; 3751 init_special_inode(inode, inode->i_mode, rdev); 3752 break; 3753 } 3754 3755 btrfs_update_iflags(inode); 3756 return 0; 3757 3758 make_bad: 3759 btrfs_free_path(path); 3760 make_bad_inode(inode); 3761 return ret; 3762 } 3763 3764 /* 3765 * given a leaf and an inode, copy the inode fields into the leaf 3766 */ 3767 static void fill_inode_item(struct btrfs_trans_handle *trans, 3768 struct extent_buffer *leaf, 3769 struct btrfs_inode_item *item, 3770 struct inode *inode) 3771 { 3772 struct btrfs_map_token token; 3773 3774 btrfs_init_map_token(&token); 3775 3776 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3777 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3778 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3779 &token); 3780 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3781 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3782 3783 btrfs_set_token_timespec_sec(leaf, &item->atime, 3784 inode->i_atime.tv_sec, &token); 3785 btrfs_set_token_timespec_nsec(leaf, &item->atime, 3786 inode->i_atime.tv_nsec, &token); 3787 3788 btrfs_set_token_timespec_sec(leaf, &item->mtime, 3789 inode->i_mtime.tv_sec, &token); 3790 btrfs_set_token_timespec_nsec(leaf, &item->mtime, 3791 inode->i_mtime.tv_nsec, &token); 3792 3793 btrfs_set_token_timespec_sec(leaf, &item->ctime, 3794 inode->i_ctime.tv_sec, &token); 3795 btrfs_set_token_timespec_nsec(leaf, &item->ctime, 3796 inode->i_ctime.tv_nsec, &token); 3797 3798 btrfs_set_token_timespec_sec(leaf, &item->otime, 3799 BTRFS_I(inode)->i_otime.tv_sec, &token); 3800 btrfs_set_token_timespec_nsec(leaf, &item->otime, 3801 BTRFS_I(inode)->i_otime.tv_nsec, &token); 3802 3803 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3804 &token); 3805 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3806 &token); 3807 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3808 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3809 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3810 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3811 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3812 } 3813 3814 /* 3815 * copy everything in the in-memory inode into the btree. 3816 */ 3817 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3818 struct btrfs_root *root, struct inode *inode) 3819 { 3820 struct btrfs_inode_item *inode_item; 3821 struct btrfs_path *path; 3822 struct extent_buffer *leaf; 3823 int ret; 3824 3825 path = btrfs_alloc_path(); 3826 if (!path) 3827 return -ENOMEM; 3828 3829 path->leave_spinning = 1; 3830 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3831 1); 3832 if (ret) { 3833 if (ret > 0) 3834 ret = -ENOENT; 3835 goto failed; 3836 } 3837 3838 leaf = path->nodes[0]; 3839 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3840 struct btrfs_inode_item); 3841 3842 fill_inode_item(trans, leaf, inode_item, inode); 3843 btrfs_mark_buffer_dirty(leaf); 3844 btrfs_set_inode_last_trans(trans, inode); 3845 ret = 0; 3846 failed: 3847 btrfs_free_path(path); 3848 return ret; 3849 } 3850 3851 /* 3852 * copy everything in the in-memory inode into the btree. 3853 */ 3854 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3855 struct btrfs_root *root, struct inode *inode) 3856 { 3857 struct btrfs_fs_info *fs_info = root->fs_info; 3858 int ret; 3859 3860 /* 3861 * If the inode is a free space inode, we can deadlock during commit 3862 * if we put it into the delayed code. 3863 * 3864 * The data relocation inode should also be directly updated 3865 * without delay 3866 */ 3867 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) 3868 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 3869 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) { 3870 btrfs_update_root_times(trans, root); 3871 3872 ret = btrfs_delayed_update_inode(trans, root, inode); 3873 if (!ret) 3874 btrfs_set_inode_last_trans(trans, inode); 3875 return ret; 3876 } 3877 3878 return btrfs_update_inode_item(trans, root, inode); 3879 } 3880 3881 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3882 struct btrfs_root *root, 3883 struct inode *inode) 3884 { 3885 int ret; 3886 3887 ret = btrfs_update_inode(trans, root, inode); 3888 if (ret == -ENOSPC) 3889 return btrfs_update_inode_item(trans, root, inode); 3890 return ret; 3891 } 3892 3893 /* 3894 * unlink helper that gets used here in inode.c and in the tree logging 3895 * recovery code. It remove a link in a directory with a given name, and 3896 * also drops the back refs in the inode to the directory 3897 */ 3898 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3899 struct btrfs_root *root, 3900 struct btrfs_inode *dir, 3901 struct btrfs_inode *inode, 3902 const char *name, int name_len) 3903 { 3904 struct btrfs_fs_info *fs_info = root->fs_info; 3905 struct btrfs_path *path; 3906 int ret = 0; 3907 struct extent_buffer *leaf; 3908 struct btrfs_dir_item *di; 3909 struct btrfs_key key; 3910 u64 index; 3911 u64 ino = btrfs_ino(inode); 3912 u64 dir_ino = btrfs_ino(dir); 3913 3914 path = btrfs_alloc_path(); 3915 if (!path) { 3916 ret = -ENOMEM; 3917 goto out; 3918 } 3919 3920 path->leave_spinning = 1; 3921 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3922 name, name_len, -1); 3923 if (IS_ERR(di)) { 3924 ret = PTR_ERR(di); 3925 goto err; 3926 } 3927 if (!di) { 3928 ret = -ENOENT; 3929 goto err; 3930 } 3931 leaf = path->nodes[0]; 3932 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3933 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3934 if (ret) 3935 goto err; 3936 btrfs_release_path(path); 3937 3938 /* 3939 * If we don't have dir index, we have to get it by looking up 3940 * the inode ref, since we get the inode ref, remove it directly, 3941 * it is unnecessary to do delayed deletion. 3942 * 3943 * But if we have dir index, needn't search inode ref to get it. 3944 * Since the inode ref is close to the inode item, it is better 3945 * that we delay to delete it, and just do this deletion when 3946 * we update the inode item. 3947 */ 3948 if (inode->dir_index) { 3949 ret = btrfs_delayed_delete_inode_ref(inode); 3950 if (!ret) { 3951 index = inode->dir_index; 3952 goto skip_backref; 3953 } 3954 } 3955 3956 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3957 dir_ino, &index); 3958 if (ret) { 3959 btrfs_info(fs_info, 3960 "failed to delete reference to %.*s, inode %llu parent %llu", 3961 name_len, name, ino, dir_ino); 3962 btrfs_abort_transaction(trans, ret); 3963 goto err; 3964 } 3965 skip_backref: 3966 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index); 3967 if (ret) { 3968 btrfs_abort_transaction(trans, ret); 3969 goto err; 3970 } 3971 3972 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode, 3973 dir_ino); 3974 if (ret != 0 && ret != -ENOENT) { 3975 btrfs_abort_transaction(trans, ret); 3976 goto err; 3977 } 3978 3979 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir, 3980 index); 3981 if (ret == -ENOENT) 3982 ret = 0; 3983 else if (ret) 3984 btrfs_abort_transaction(trans, ret); 3985 err: 3986 btrfs_free_path(path); 3987 if (ret) 3988 goto out; 3989 3990 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2); 3991 inode_inc_iversion(&inode->vfs_inode); 3992 inode_inc_iversion(&dir->vfs_inode); 3993 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime = 3994 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode); 3995 ret = btrfs_update_inode(trans, root, &dir->vfs_inode); 3996 out: 3997 return ret; 3998 } 3999 4000 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 4001 struct btrfs_root *root, 4002 struct btrfs_inode *dir, struct btrfs_inode *inode, 4003 const char *name, int name_len) 4004 { 4005 int ret; 4006 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 4007 if (!ret) { 4008 drop_nlink(&inode->vfs_inode); 4009 ret = btrfs_update_inode(trans, root, &inode->vfs_inode); 4010 } 4011 return ret; 4012 } 4013 4014 /* 4015 * helper to start transaction for unlink and rmdir. 4016 * 4017 * unlink and rmdir are special in btrfs, they do not always free space, so 4018 * if we cannot make our reservations the normal way try and see if there is 4019 * plenty of slack room in the global reserve to migrate, otherwise we cannot 4020 * allow the unlink to occur. 4021 */ 4022 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) 4023 { 4024 struct btrfs_root *root = BTRFS_I(dir)->root; 4025 4026 /* 4027 * 1 for the possible orphan item 4028 * 1 for the dir item 4029 * 1 for the dir index 4030 * 1 for the inode ref 4031 * 1 for the inode 4032 */ 4033 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5); 4034 } 4035 4036 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 4037 { 4038 struct btrfs_root *root = BTRFS_I(dir)->root; 4039 struct btrfs_trans_handle *trans; 4040 struct inode *inode = d_inode(dentry); 4041 int ret; 4042 4043 trans = __unlink_start_trans(dir); 4044 if (IS_ERR(trans)) 4045 return PTR_ERR(trans); 4046 4047 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)), 4048 0); 4049 4050 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), 4051 BTRFS_I(d_inode(dentry)), dentry->d_name.name, 4052 dentry->d_name.len); 4053 if (ret) 4054 goto out; 4055 4056 if (inode->i_nlink == 0) { 4057 ret = btrfs_orphan_add(trans, BTRFS_I(inode)); 4058 if (ret) 4059 goto out; 4060 } 4061 4062 out: 4063 btrfs_end_transaction(trans); 4064 btrfs_btree_balance_dirty(root->fs_info); 4065 return ret; 4066 } 4067 4068 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 4069 struct btrfs_root *root, 4070 struct inode *dir, u64 objectid, 4071 const char *name, int name_len) 4072 { 4073 struct btrfs_fs_info *fs_info = root->fs_info; 4074 struct btrfs_path *path; 4075 struct extent_buffer *leaf; 4076 struct btrfs_dir_item *di; 4077 struct btrfs_key key; 4078 u64 index; 4079 int ret; 4080 u64 dir_ino = btrfs_ino(BTRFS_I(dir)); 4081 4082 path = btrfs_alloc_path(); 4083 if (!path) 4084 return -ENOMEM; 4085 4086 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 4087 name, name_len, -1); 4088 if (IS_ERR_OR_NULL(di)) { 4089 if (!di) 4090 ret = -ENOENT; 4091 else 4092 ret = PTR_ERR(di); 4093 goto out; 4094 } 4095 4096 leaf = path->nodes[0]; 4097 btrfs_dir_item_key_to_cpu(leaf, di, &key); 4098 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 4099 ret = btrfs_delete_one_dir_name(trans, root, path, di); 4100 if (ret) { 4101 btrfs_abort_transaction(trans, ret); 4102 goto out; 4103 } 4104 btrfs_release_path(path); 4105 4106 ret = btrfs_del_root_ref(trans, fs_info, objectid, 4107 root->root_key.objectid, dir_ino, 4108 &index, name, name_len); 4109 if (ret < 0) { 4110 if (ret != -ENOENT) { 4111 btrfs_abort_transaction(trans, ret); 4112 goto out; 4113 } 4114 di = btrfs_search_dir_index_item(root, path, dir_ino, 4115 name, name_len); 4116 if (IS_ERR_OR_NULL(di)) { 4117 if (!di) 4118 ret = -ENOENT; 4119 else 4120 ret = PTR_ERR(di); 4121 btrfs_abort_transaction(trans, ret); 4122 goto out; 4123 } 4124 4125 leaf = path->nodes[0]; 4126 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4127 btrfs_release_path(path); 4128 index = key.offset; 4129 } 4130 btrfs_release_path(path); 4131 4132 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index); 4133 if (ret) { 4134 btrfs_abort_transaction(trans, ret); 4135 goto out; 4136 } 4137 4138 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2); 4139 inode_inc_iversion(dir); 4140 dir->i_mtime = dir->i_ctime = current_time(dir); 4141 ret = btrfs_update_inode_fallback(trans, root, dir); 4142 if (ret) 4143 btrfs_abort_transaction(trans, ret); 4144 out: 4145 btrfs_free_path(path); 4146 return ret; 4147 } 4148 4149 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 4150 { 4151 struct inode *inode = d_inode(dentry); 4152 int err = 0; 4153 struct btrfs_root *root = BTRFS_I(dir)->root; 4154 struct btrfs_trans_handle *trans; 4155 u64 last_unlink_trans; 4156 4157 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 4158 return -ENOTEMPTY; 4159 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID) 4160 return -EPERM; 4161 4162 trans = __unlink_start_trans(dir); 4163 if (IS_ERR(trans)) 4164 return PTR_ERR(trans); 4165 4166 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 4167 err = btrfs_unlink_subvol(trans, root, dir, 4168 BTRFS_I(inode)->location.objectid, 4169 dentry->d_name.name, 4170 dentry->d_name.len); 4171 goto out; 4172 } 4173 4174 err = btrfs_orphan_add(trans, BTRFS_I(inode)); 4175 if (err) 4176 goto out; 4177 4178 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans; 4179 4180 /* now the directory is empty */ 4181 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir), 4182 BTRFS_I(d_inode(dentry)), dentry->d_name.name, 4183 dentry->d_name.len); 4184 if (!err) { 4185 btrfs_i_size_write(BTRFS_I(inode), 0); 4186 /* 4187 * Propagate the last_unlink_trans value of the deleted dir to 4188 * its parent directory. This is to prevent an unrecoverable 4189 * log tree in the case we do something like this: 4190 * 1) create dir foo 4191 * 2) create snapshot under dir foo 4192 * 3) delete the snapshot 4193 * 4) rmdir foo 4194 * 5) mkdir foo 4195 * 6) fsync foo or some file inside foo 4196 */ 4197 if (last_unlink_trans >= trans->transid) 4198 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans; 4199 } 4200 out: 4201 btrfs_end_transaction(trans); 4202 btrfs_btree_balance_dirty(root->fs_info); 4203 4204 return err; 4205 } 4206 4207 static int truncate_space_check(struct btrfs_trans_handle *trans, 4208 struct btrfs_root *root, 4209 u64 bytes_deleted) 4210 { 4211 struct btrfs_fs_info *fs_info = root->fs_info; 4212 int ret; 4213 4214 /* 4215 * This is only used to apply pressure to the enospc system, we don't 4216 * intend to use this reservation at all. 4217 */ 4218 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted); 4219 bytes_deleted *= fs_info->nodesize; 4220 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv, 4221 bytes_deleted, BTRFS_RESERVE_NO_FLUSH); 4222 if (!ret) { 4223 trace_btrfs_space_reservation(fs_info, "transaction", 4224 trans->transid, 4225 bytes_deleted, 1); 4226 trans->bytes_reserved += bytes_deleted; 4227 } 4228 return ret; 4229 4230 } 4231 4232 static int truncate_inline_extent(struct inode *inode, 4233 struct btrfs_path *path, 4234 struct btrfs_key *found_key, 4235 const u64 item_end, 4236 const u64 new_size) 4237 { 4238 struct extent_buffer *leaf = path->nodes[0]; 4239 int slot = path->slots[0]; 4240 struct btrfs_file_extent_item *fi; 4241 u32 size = (u32)(new_size - found_key->offset); 4242 struct btrfs_root *root = BTRFS_I(inode)->root; 4243 4244 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 4245 4246 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) { 4247 loff_t offset = new_size; 4248 loff_t page_end = ALIGN(offset, PAGE_SIZE); 4249 4250 /* 4251 * Zero out the remaining of the last page of our inline extent, 4252 * instead of directly truncating our inline extent here - that 4253 * would be much more complex (decompressing all the data, then 4254 * compressing the truncated data, which might be bigger than 4255 * the size of the inline extent, resize the extent, etc). 4256 * We release the path because to get the page we might need to 4257 * read the extent item from disk (data not in the page cache). 4258 */ 4259 btrfs_release_path(path); 4260 return btrfs_truncate_block(inode, offset, page_end - offset, 4261 0); 4262 } 4263 4264 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 4265 size = btrfs_file_extent_calc_inline_size(size); 4266 btrfs_truncate_item(root->fs_info, path, size, 1); 4267 4268 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 4269 inode_sub_bytes(inode, item_end + 1 - new_size); 4270 4271 return 0; 4272 } 4273 4274 /* 4275 * this can truncate away extent items, csum items and directory items. 4276 * It starts at a high offset and removes keys until it can't find 4277 * any higher than new_size 4278 * 4279 * csum items that cross the new i_size are truncated to the new size 4280 * as well. 4281 * 4282 * min_type is the minimum key type to truncate down to. If set to 0, this 4283 * will kill all the items on this inode, including the INODE_ITEM_KEY. 4284 */ 4285 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 4286 struct btrfs_root *root, 4287 struct inode *inode, 4288 u64 new_size, u32 min_type) 4289 { 4290 struct btrfs_fs_info *fs_info = root->fs_info; 4291 struct btrfs_path *path; 4292 struct extent_buffer *leaf; 4293 struct btrfs_file_extent_item *fi; 4294 struct btrfs_key key; 4295 struct btrfs_key found_key; 4296 u64 extent_start = 0; 4297 u64 extent_num_bytes = 0; 4298 u64 extent_offset = 0; 4299 u64 item_end = 0; 4300 u64 last_size = new_size; 4301 u32 found_type = (u8)-1; 4302 int found_extent; 4303 int del_item; 4304 int pending_del_nr = 0; 4305 int pending_del_slot = 0; 4306 int extent_type = -1; 4307 int ret; 4308 int err = 0; 4309 u64 ino = btrfs_ino(BTRFS_I(inode)); 4310 u64 bytes_deleted = 0; 4311 bool be_nice = 0; 4312 bool should_throttle = 0; 4313 bool should_end = 0; 4314 4315 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 4316 4317 /* 4318 * for non-free space inodes and ref cows, we want to back off from 4319 * time to time 4320 */ 4321 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) && 4322 test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 4323 be_nice = 1; 4324 4325 path = btrfs_alloc_path(); 4326 if (!path) 4327 return -ENOMEM; 4328 path->reada = READA_BACK; 4329 4330 /* 4331 * We want to drop from the next block forward in case this new size is 4332 * not block aligned since we will be keeping the last block of the 4333 * extent just the way it is. 4334 */ 4335 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 4336 root == fs_info->tree_root) 4337 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size, 4338 fs_info->sectorsize), 4339 (u64)-1, 0); 4340 4341 /* 4342 * This function is also used to drop the items in the log tree before 4343 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 4344 * it is used to drop the loged items. So we shouldn't kill the delayed 4345 * items. 4346 */ 4347 if (min_type == 0 && root == BTRFS_I(inode)->root) 4348 btrfs_kill_delayed_inode_items(BTRFS_I(inode)); 4349 4350 key.objectid = ino; 4351 key.offset = (u64)-1; 4352 key.type = (u8)-1; 4353 4354 search_again: 4355 /* 4356 * with a 16K leaf size and 128MB extents, you can actually queue 4357 * up a huge file in a single leaf. Most of the time that 4358 * bytes_deleted is > 0, it will be huge by the time we get here 4359 */ 4360 if (be_nice && bytes_deleted > SZ_32M) { 4361 if (btrfs_should_end_transaction(trans)) { 4362 err = -EAGAIN; 4363 goto error; 4364 } 4365 } 4366 4367 4368 path->leave_spinning = 1; 4369 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 4370 if (ret < 0) { 4371 err = ret; 4372 goto out; 4373 } 4374 4375 if (ret > 0) { 4376 /* there are no items in the tree for us to truncate, we're 4377 * done 4378 */ 4379 if (path->slots[0] == 0) 4380 goto out; 4381 path->slots[0]--; 4382 } 4383 4384 while (1) { 4385 fi = NULL; 4386 leaf = path->nodes[0]; 4387 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4388 found_type = found_key.type; 4389 4390 if (found_key.objectid != ino) 4391 break; 4392 4393 if (found_type < min_type) 4394 break; 4395 4396 item_end = found_key.offset; 4397 if (found_type == BTRFS_EXTENT_DATA_KEY) { 4398 fi = btrfs_item_ptr(leaf, path->slots[0], 4399 struct btrfs_file_extent_item); 4400 extent_type = btrfs_file_extent_type(leaf, fi); 4401 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4402 item_end += 4403 btrfs_file_extent_num_bytes(leaf, fi); 4404 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4405 item_end += btrfs_file_extent_inline_len(leaf, 4406 path->slots[0], fi); 4407 } 4408 item_end--; 4409 } 4410 if (found_type > min_type) { 4411 del_item = 1; 4412 } else { 4413 if (item_end < new_size) 4414 break; 4415 if (found_key.offset >= new_size) 4416 del_item = 1; 4417 else 4418 del_item = 0; 4419 } 4420 found_extent = 0; 4421 /* FIXME, shrink the extent if the ref count is only 1 */ 4422 if (found_type != BTRFS_EXTENT_DATA_KEY) 4423 goto delete; 4424 4425 if (del_item) 4426 last_size = found_key.offset; 4427 else 4428 last_size = new_size; 4429 4430 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4431 u64 num_dec; 4432 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4433 if (!del_item) { 4434 u64 orig_num_bytes = 4435 btrfs_file_extent_num_bytes(leaf, fi); 4436 extent_num_bytes = ALIGN(new_size - 4437 found_key.offset, 4438 fs_info->sectorsize); 4439 btrfs_set_file_extent_num_bytes(leaf, fi, 4440 extent_num_bytes); 4441 num_dec = (orig_num_bytes - 4442 extent_num_bytes); 4443 if (test_bit(BTRFS_ROOT_REF_COWS, 4444 &root->state) && 4445 extent_start != 0) 4446 inode_sub_bytes(inode, num_dec); 4447 btrfs_mark_buffer_dirty(leaf); 4448 } else { 4449 extent_num_bytes = 4450 btrfs_file_extent_disk_num_bytes(leaf, 4451 fi); 4452 extent_offset = found_key.offset - 4453 btrfs_file_extent_offset(leaf, fi); 4454 4455 /* FIXME blocksize != 4096 */ 4456 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4457 if (extent_start != 0) { 4458 found_extent = 1; 4459 if (test_bit(BTRFS_ROOT_REF_COWS, 4460 &root->state)) 4461 inode_sub_bytes(inode, num_dec); 4462 } 4463 } 4464 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4465 /* 4466 * we can't truncate inline items that have had 4467 * special encodings 4468 */ 4469 if (!del_item && 4470 btrfs_file_extent_encryption(leaf, fi) == 0 && 4471 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4472 4473 /* 4474 * Need to release path in order to truncate a 4475 * compressed extent. So delete any accumulated 4476 * extent items so far. 4477 */ 4478 if (btrfs_file_extent_compression(leaf, fi) != 4479 BTRFS_COMPRESS_NONE && pending_del_nr) { 4480 err = btrfs_del_items(trans, root, path, 4481 pending_del_slot, 4482 pending_del_nr); 4483 if (err) { 4484 btrfs_abort_transaction(trans, 4485 err); 4486 goto error; 4487 } 4488 pending_del_nr = 0; 4489 } 4490 4491 err = truncate_inline_extent(inode, path, 4492 &found_key, 4493 item_end, 4494 new_size); 4495 if (err) { 4496 btrfs_abort_transaction(trans, err); 4497 goto error; 4498 } 4499 } else if (test_bit(BTRFS_ROOT_REF_COWS, 4500 &root->state)) { 4501 inode_sub_bytes(inode, item_end + 1 - new_size); 4502 } 4503 } 4504 delete: 4505 if (del_item) { 4506 if (!pending_del_nr) { 4507 /* no pending yet, add ourselves */ 4508 pending_del_slot = path->slots[0]; 4509 pending_del_nr = 1; 4510 } else if (pending_del_nr && 4511 path->slots[0] + 1 == pending_del_slot) { 4512 /* hop on the pending chunk */ 4513 pending_del_nr++; 4514 pending_del_slot = path->slots[0]; 4515 } else { 4516 BUG(); 4517 } 4518 } else { 4519 break; 4520 } 4521 should_throttle = 0; 4522 4523 if (found_extent && 4524 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 4525 root == fs_info->tree_root)) { 4526 btrfs_set_path_blocking(path); 4527 bytes_deleted += extent_num_bytes; 4528 ret = btrfs_free_extent(trans, fs_info, extent_start, 4529 extent_num_bytes, 0, 4530 btrfs_header_owner(leaf), 4531 ino, extent_offset); 4532 BUG_ON(ret); 4533 if (btrfs_should_throttle_delayed_refs(trans, fs_info)) 4534 btrfs_async_run_delayed_refs(fs_info, 4535 trans->delayed_ref_updates * 2, 4536 trans->transid, 0); 4537 if (be_nice) { 4538 if (truncate_space_check(trans, root, 4539 extent_num_bytes)) { 4540 should_end = 1; 4541 } 4542 if (btrfs_should_throttle_delayed_refs(trans, 4543 fs_info)) 4544 should_throttle = 1; 4545 } 4546 } 4547 4548 if (found_type == BTRFS_INODE_ITEM_KEY) 4549 break; 4550 4551 if (path->slots[0] == 0 || 4552 path->slots[0] != pending_del_slot || 4553 should_throttle || should_end) { 4554 if (pending_del_nr) { 4555 ret = btrfs_del_items(trans, root, path, 4556 pending_del_slot, 4557 pending_del_nr); 4558 if (ret) { 4559 btrfs_abort_transaction(trans, ret); 4560 goto error; 4561 } 4562 pending_del_nr = 0; 4563 } 4564 btrfs_release_path(path); 4565 if (should_throttle) { 4566 unsigned long updates = trans->delayed_ref_updates; 4567 if (updates) { 4568 trans->delayed_ref_updates = 0; 4569 ret = btrfs_run_delayed_refs(trans, 4570 fs_info, 4571 updates * 2); 4572 if (ret && !err) 4573 err = ret; 4574 } 4575 } 4576 /* 4577 * if we failed to refill our space rsv, bail out 4578 * and let the transaction restart 4579 */ 4580 if (should_end) { 4581 err = -EAGAIN; 4582 goto error; 4583 } 4584 goto search_again; 4585 } else { 4586 path->slots[0]--; 4587 } 4588 } 4589 out: 4590 if (pending_del_nr) { 4591 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4592 pending_del_nr); 4593 if (ret) 4594 btrfs_abort_transaction(trans, ret); 4595 } 4596 error: 4597 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { 4598 ASSERT(last_size >= new_size); 4599 if (!err && last_size > new_size) 4600 last_size = new_size; 4601 btrfs_ordered_update_i_size(inode, last_size, NULL); 4602 } 4603 4604 btrfs_free_path(path); 4605 4606 if (err == 0) { 4607 /* only inline file may have last_size != new_size */ 4608 if (new_size >= fs_info->sectorsize || 4609 new_size > fs_info->max_inline) 4610 ASSERT(last_size == new_size); 4611 } 4612 4613 if (be_nice && bytes_deleted > SZ_32M) { 4614 unsigned long updates = trans->delayed_ref_updates; 4615 if (updates) { 4616 trans->delayed_ref_updates = 0; 4617 ret = btrfs_run_delayed_refs(trans, fs_info, 4618 updates * 2); 4619 if (ret && !err) 4620 err = ret; 4621 } 4622 } 4623 return err; 4624 } 4625 4626 /* 4627 * btrfs_truncate_block - read, zero a chunk and write a block 4628 * @inode - inode that we're zeroing 4629 * @from - the offset to start zeroing 4630 * @len - the length to zero, 0 to zero the entire range respective to the 4631 * offset 4632 * @front - zero up to the offset instead of from the offset on 4633 * 4634 * This will find the block for the "from" offset and cow the block and zero the 4635 * part we want to zero. This is used with truncate and hole punching. 4636 */ 4637 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len, 4638 int front) 4639 { 4640 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 4641 struct address_space *mapping = inode->i_mapping; 4642 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4643 struct btrfs_ordered_extent *ordered; 4644 struct extent_state *cached_state = NULL; 4645 char *kaddr; 4646 u32 blocksize = fs_info->sectorsize; 4647 pgoff_t index = from >> PAGE_SHIFT; 4648 unsigned offset = from & (blocksize - 1); 4649 struct page *page; 4650 gfp_t mask = btrfs_alloc_write_mask(mapping); 4651 int ret = 0; 4652 u64 block_start; 4653 u64 block_end; 4654 4655 if ((offset & (blocksize - 1)) == 0 && 4656 (!len || ((len & (blocksize - 1)) == 0))) 4657 goto out; 4658 4659 ret = btrfs_delalloc_reserve_space(inode, 4660 round_down(from, blocksize), blocksize); 4661 if (ret) 4662 goto out; 4663 4664 again: 4665 page = find_or_create_page(mapping, index, mask); 4666 if (!page) { 4667 btrfs_delalloc_release_space(inode, 4668 round_down(from, blocksize), 4669 blocksize); 4670 ret = -ENOMEM; 4671 goto out; 4672 } 4673 4674 block_start = round_down(from, blocksize); 4675 block_end = block_start + blocksize - 1; 4676 4677 if (!PageUptodate(page)) { 4678 ret = btrfs_readpage(NULL, page); 4679 lock_page(page); 4680 if (page->mapping != mapping) { 4681 unlock_page(page); 4682 put_page(page); 4683 goto again; 4684 } 4685 if (!PageUptodate(page)) { 4686 ret = -EIO; 4687 goto out_unlock; 4688 } 4689 } 4690 wait_on_page_writeback(page); 4691 4692 lock_extent_bits(io_tree, block_start, block_end, &cached_state); 4693 set_page_extent_mapped(page); 4694 4695 ordered = btrfs_lookup_ordered_extent(inode, block_start); 4696 if (ordered) { 4697 unlock_extent_cached(io_tree, block_start, block_end, 4698 &cached_state, GFP_NOFS); 4699 unlock_page(page); 4700 put_page(page); 4701 btrfs_start_ordered_extent(inode, ordered, 1); 4702 btrfs_put_ordered_extent(ordered); 4703 goto again; 4704 } 4705 4706 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end, 4707 EXTENT_DIRTY | EXTENT_DELALLOC | 4708 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4709 0, 0, &cached_state, GFP_NOFS); 4710 4711 ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 4712 &cached_state, 0); 4713 if (ret) { 4714 unlock_extent_cached(io_tree, block_start, block_end, 4715 &cached_state, GFP_NOFS); 4716 goto out_unlock; 4717 } 4718 4719 if (offset != blocksize) { 4720 if (!len) 4721 len = blocksize - offset; 4722 kaddr = kmap(page); 4723 if (front) 4724 memset(kaddr + (block_start - page_offset(page)), 4725 0, offset); 4726 else 4727 memset(kaddr + (block_start - page_offset(page)) + offset, 4728 0, len); 4729 flush_dcache_page(page); 4730 kunmap(page); 4731 } 4732 ClearPageChecked(page); 4733 set_page_dirty(page); 4734 unlock_extent_cached(io_tree, block_start, block_end, &cached_state, 4735 GFP_NOFS); 4736 4737 out_unlock: 4738 if (ret) 4739 btrfs_delalloc_release_space(inode, block_start, 4740 blocksize); 4741 unlock_page(page); 4742 put_page(page); 4743 out: 4744 return ret; 4745 } 4746 4747 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, 4748 u64 offset, u64 len) 4749 { 4750 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 4751 struct btrfs_trans_handle *trans; 4752 int ret; 4753 4754 /* 4755 * Still need to make sure the inode looks like it's been updated so 4756 * that any holes get logged if we fsync. 4757 */ 4758 if (btrfs_fs_incompat(fs_info, NO_HOLES)) { 4759 BTRFS_I(inode)->last_trans = fs_info->generation; 4760 BTRFS_I(inode)->last_sub_trans = root->log_transid; 4761 BTRFS_I(inode)->last_log_commit = root->last_log_commit; 4762 return 0; 4763 } 4764 4765 /* 4766 * 1 - for the one we're dropping 4767 * 1 - for the one we're adding 4768 * 1 - for updating the inode. 4769 */ 4770 trans = btrfs_start_transaction(root, 3); 4771 if (IS_ERR(trans)) 4772 return PTR_ERR(trans); 4773 4774 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); 4775 if (ret) { 4776 btrfs_abort_transaction(trans, ret); 4777 btrfs_end_transaction(trans); 4778 return ret; 4779 } 4780 4781 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)), 4782 offset, 0, 0, len, 0, len, 0, 0, 0); 4783 if (ret) 4784 btrfs_abort_transaction(trans, ret); 4785 else 4786 btrfs_update_inode(trans, root, inode); 4787 btrfs_end_transaction(trans); 4788 return ret; 4789 } 4790 4791 /* 4792 * This function puts in dummy file extents for the area we're creating a hole 4793 * for. So if we are truncating this file to a larger size we need to insert 4794 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4795 * the range between oldsize and size 4796 */ 4797 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4798 { 4799 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 4800 struct btrfs_root *root = BTRFS_I(inode)->root; 4801 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4802 struct extent_map *em = NULL; 4803 struct extent_state *cached_state = NULL; 4804 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4805 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize); 4806 u64 block_end = ALIGN(size, fs_info->sectorsize); 4807 u64 last_byte; 4808 u64 cur_offset; 4809 u64 hole_size; 4810 int err = 0; 4811 4812 /* 4813 * If our size started in the middle of a block we need to zero out the 4814 * rest of the block before we expand the i_size, otherwise we could 4815 * expose stale data. 4816 */ 4817 err = btrfs_truncate_block(inode, oldsize, 0, 0); 4818 if (err) 4819 return err; 4820 4821 if (size <= hole_start) 4822 return 0; 4823 4824 while (1) { 4825 struct btrfs_ordered_extent *ordered; 4826 4827 lock_extent_bits(io_tree, hole_start, block_end - 1, 4828 &cached_state); 4829 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start, 4830 block_end - hole_start); 4831 if (!ordered) 4832 break; 4833 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4834 &cached_state, GFP_NOFS); 4835 btrfs_start_ordered_extent(inode, ordered, 1); 4836 btrfs_put_ordered_extent(ordered); 4837 } 4838 4839 cur_offset = hole_start; 4840 while (1) { 4841 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset, 4842 block_end - cur_offset, 0); 4843 if (IS_ERR(em)) { 4844 err = PTR_ERR(em); 4845 em = NULL; 4846 break; 4847 } 4848 last_byte = min(extent_map_end(em), block_end); 4849 last_byte = ALIGN(last_byte, fs_info->sectorsize); 4850 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4851 struct extent_map *hole_em; 4852 hole_size = last_byte - cur_offset; 4853 4854 err = maybe_insert_hole(root, inode, cur_offset, 4855 hole_size); 4856 if (err) 4857 break; 4858 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset, 4859 cur_offset + hole_size - 1, 0); 4860 hole_em = alloc_extent_map(); 4861 if (!hole_em) { 4862 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4863 &BTRFS_I(inode)->runtime_flags); 4864 goto next; 4865 } 4866 hole_em->start = cur_offset; 4867 hole_em->len = hole_size; 4868 hole_em->orig_start = cur_offset; 4869 4870 hole_em->block_start = EXTENT_MAP_HOLE; 4871 hole_em->block_len = 0; 4872 hole_em->orig_block_len = 0; 4873 hole_em->ram_bytes = hole_size; 4874 hole_em->bdev = fs_info->fs_devices->latest_bdev; 4875 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4876 hole_em->generation = fs_info->generation; 4877 4878 while (1) { 4879 write_lock(&em_tree->lock); 4880 err = add_extent_mapping(em_tree, hole_em, 1); 4881 write_unlock(&em_tree->lock); 4882 if (err != -EEXIST) 4883 break; 4884 btrfs_drop_extent_cache(BTRFS_I(inode), 4885 cur_offset, 4886 cur_offset + 4887 hole_size - 1, 0); 4888 } 4889 free_extent_map(hole_em); 4890 } 4891 next: 4892 free_extent_map(em); 4893 em = NULL; 4894 cur_offset = last_byte; 4895 if (cur_offset >= block_end) 4896 break; 4897 } 4898 free_extent_map(em); 4899 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4900 GFP_NOFS); 4901 return err; 4902 } 4903 4904 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4905 { 4906 struct btrfs_root *root = BTRFS_I(inode)->root; 4907 struct btrfs_trans_handle *trans; 4908 loff_t oldsize = i_size_read(inode); 4909 loff_t newsize = attr->ia_size; 4910 int mask = attr->ia_valid; 4911 int ret; 4912 4913 /* 4914 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4915 * special case where we need to update the times despite not having 4916 * these flags set. For all other operations the VFS set these flags 4917 * explicitly if it wants a timestamp update. 4918 */ 4919 if (newsize != oldsize) { 4920 inode_inc_iversion(inode); 4921 if (!(mask & (ATTR_CTIME | ATTR_MTIME))) 4922 inode->i_ctime = inode->i_mtime = 4923 current_time(inode); 4924 } 4925 4926 if (newsize > oldsize) { 4927 /* 4928 * Don't do an expanding truncate while snapshoting is ongoing. 4929 * This is to ensure the snapshot captures a fully consistent 4930 * state of this file - if the snapshot captures this expanding 4931 * truncation, it must capture all writes that happened before 4932 * this truncation. 4933 */ 4934 btrfs_wait_for_snapshot_creation(root); 4935 ret = btrfs_cont_expand(inode, oldsize, newsize); 4936 if (ret) { 4937 btrfs_end_write_no_snapshoting(root); 4938 return ret; 4939 } 4940 4941 trans = btrfs_start_transaction(root, 1); 4942 if (IS_ERR(trans)) { 4943 btrfs_end_write_no_snapshoting(root); 4944 return PTR_ERR(trans); 4945 } 4946 4947 i_size_write(inode, newsize); 4948 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4949 pagecache_isize_extended(inode, oldsize, newsize); 4950 ret = btrfs_update_inode(trans, root, inode); 4951 btrfs_end_write_no_snapshoting(root); 4952 btrfs_end_transaction(trans); 4953 } else { 4954 4955 /* 4956 * We're truncating a file that used to have good data down to 4957 * zero. Make sure it gets into the ordered flush list so that 4958 * any new writes get down to disk quickly. 4959 */ 4960 if (newsize == 0) 4961 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4962 &BTRFS_I(inode)->runtime_flags); 4963 4964 /* 4965 * 1 for the orphan item we're going to add 4966 * 1 for the orphan item deletion. 4967 */ 4968 trans = btrfs_start_transaction(root, 2); 4969 if (IS_ERR(trans)) 4970 return PTR_ERR(trans); 4971 4972 /* 4973 * We need to do this in case we fail at _any_ point during the 4974 * actual truncate. Once we do the truncate_setsize we could 4975 * invalidate pages which forces any outstanding ordered io to 4976 * be instantly completed which will give us extents that need 4977 * to be truncated. If we fail to get an orphan inode down we 4978 * could have left over extents that were never meant to live, 4979 * so we need to guarantee from this point on that everything 4980 * will be consistent. 4981 */ 4982 ret = btrfs_orphan_add(trans, BTRFS_I(inode)); 4983 btrfs_end_transaction(trans); 4984 if (ret) 4985 return ret; 4986 4987 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4988 truncate_setsize(inode, newsize); 4989 4990 /* Disable nonlocked read DIO to avoid the end less truncate */ 4991 btrfs_inode_block_unlocked_dio(BTRFS_I(inode)); 4992 inode_dio_wait(inode); 4993 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode)); 4994 4995 ret = btrfs_truncate(inode); 4996 if (ret && inode->i_nlink) { 4997 int err; 4998 4999 /* To get a stable disk_i_size */ 5000 err = btrfs_wait_ordered_range(inode, 0, (u64)-1); 5001 if (err) { 5002 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5003 return err; 5004 } 5005 5006 /* 5007 * failed to truncate, disk_i_size is only adjusted down 5008 * as we remove extents, so it should represent the true 5009 * size of the inode, so reset the in memory size and 5010 * delete our orphan entry. 5011 */ 5012 trans = btrfs_join_transaction(root); 5013 if (IS_ERR(trans)) { 5014 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5015 return ret; 5016 } 5017 i_size_write(inode, BTRFS_I(inode)->disk_i_size); 5018 err = btrfs_orphan_del(trans, BTRFS_I(inode)); 5019 if (err) 5020 btrfs_abort_transaction(trans, err); 5021 btrfs_end_transaction(trans); 5022 } 5023 } 5024 5025 return ret; 5026 } 5027 5028 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 5029 { 5030 struct inode *inode = d_inode(dentry); 5031 struct btrfs_root *root = BTRFS_I(inode)->root; 5032 int err; 5033 5034 if (btrfs_root_readonly(root)) 5035 return -EROFS; 5036 5037 err = setattr_prepare(dentry, attr); 5038 if (err) 5039 return err; 5040 5041 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 5042 err = btrfs_setsize(inode, attr); 5043 if (err) 5044 return err; 5045 } 5046 5047 if (attr->ia_valid) { 5048 setattr_copy(inode, attr); 5049 inode_inc_iversion(inode); 5050 err = btrfs_dirty_inode(inode); 5051 5052 if (!err && attr->ia_valid & ATTR_MODE) 5053 err = posix_acl_chmod(inode, inode->i_mode); 5054 } 5055 5056 return err; 5057 } 5058 5059 /* 5060 * While truncating the inode pages during eviction, we get the VFS calling 5061 * btrfs_invalidatepage() against each page of the inode. This is slow because 5062 * the calls to btrfs_invalidatepage() result in a huge amount of calls to 5063 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting 5064 * extent_state structures over and over, wasting lots of time. 5065 * 5066 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all 5067 * those expensive operations on a per page basis and do only the ordered io 5068 * finishing, while we release here the extent_map and extent_state structures, 5069 * without the excessive merging and splitting. 5070 */ 5071 static void evict_inode_truncate_pages(struct inode *inode) 5072 { 5073 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 5074 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; 5075 struct rb_node *node; 5076 5077 ASSERT(inode->i_state & I_FREEING); 5078 truncate_inode_pages_final(&inode->i_data); 5079 5080 write_lock(&map_tree->lock); 5081 while (!RB_EMPTY_ROOT(&map_tree->map)) { 5082 struct extent_map *em; 5083 5084 node = rb_first(&map_tree->map); 5085 em = rb_entry(node, struct extent_map, rb_node); 5086 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 5087 clear_bit(EXTENT_FLAG_LOGGING, &em->flags); 5088 remove_extent_mapping(map_tree, em); 5089 free_extent_map(em); 5090 if (need_resched()) { 5091 write_unlock(&map_tree->lock); 5092 cond_resched(); 5093 write_lock(&map_tree->lock); 5094 } 5095 } 5096 write_unlock(&map_tree->lock); 5097 5098 /* 5099 * Keep looping until we have no more ranges in the io tree. 5100 * We can have ongoing bios started by readpages (called from readahead) 5101 * that have their endio callback (extent_io.c:end_bio_extent_readpage) 5102 * still in progress (unlocked the pages in the bio but did not yet 5103 * unlocked the ranges in the io tree). Therefore this means some 5104 * ranges can still be locked and eviction started because before 5105 * submitting those bios, which are executed by a separate task (work 5106 * queue kthread), inode references (inode->i_count) were not taken 5107 * (which would be dropped in the end io callback of each bio). 5108 * Therefore here we effectively end up waiting for those bios and 5109 * anyone else holding locked ranges without having bumped the inode's 5110 * reference count - if we don't do it, when they access the inode's 5111 * io_tree to unlock a range it may be too late, leading to an 5112 * use-after-free issue. 5113 */ 5114 spin_lock(&io_tree->lock); 5115 while (!RB_EMPTY_ROOT(&io_tree->state)) { 5116 struct extent_state *state; 5117 struct extent_state *cached_state = NULL; 5118 u64 start; 5119 u64 end; 5120 5121 node = rb_first(&io_tree->state); 5122 state = rb_entry(node, struct extent_state, rb_node); 5123 start = state->start; 5124 end = state->end; 5125 spin_unlock(&io_tree->lock); 5126 5127 lock_extent_bits(io_tree, start, end, &cached_state); 5128 5129 /* 5130 * If still has DELALLOC flag, the extent didn't reach disk, 5131 * and its reserved space won't be freed by delayed_ref. 5132 * So we need to free its reserved space here. 5133 * (Refer to comment in btrfs_invalidatepage, case 2) 5134 * 5135 * Note, end is the bytenr of last byte, so we need + 1 here. 5136 */ 5137 if (state->state & EXTENT_DELALLOC) 5138 btrfs_qgroup_free_data(inode, start, end - start + 1); 5139 5140 clear_extent_bit(io_tree, start, end, 5141 EXTENT_LOCKED | EXTENT_DIRTY | 5142 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 5143 EXTENT_DEFRAG, 1, 1, 5144 &cached_state, GFP_NOFS); 5145 5146 cond_resched(); 5147 spin_lock(&io_tree->lock); 5148 } 5149 spin_unlock(&io_tree->lock); 5150 } 5151 5152 void btrfs_evict_inode(struct inode *inode) 5153 { 5154 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 5155 struct btrfs_trans_handle *trans; 5156 struct btrfs_root *root = BTRFS_I(inode)->root; 5157 struct btrfs_block_rsv *rsv, *global_rsv; 5158 int steal_from_global = 0; 5159 u64 min_size; 5160 int ret; 5161 5162 trace_btrfs_inode_evict(inode); 5163 5164 if (!root) { 5165 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 5166 return; 5167 } 5168 5169 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1); 5170 5171 evict_inode_truncate_pages(inode); 5172 5173 if (inode->i_nlink && 5174 ((btrfs_root_refs(&root->root_item) != 0 && 5175 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || 5176 btrfs_is_free_space_inode(BTRFS_I(inode)))) 5177 goto no_delete; 5178 5179 if (is_bad_inode(inode)) { 5180 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5181 goto no_delete; 5182 } 5183 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 5184 if (!special_file(inode->i_mode)) 5185 btrfs_wait_ordered_range(inode, 0, (u64)-1); 5186 5187 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1); 5188 5189 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) { 5190 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 5191 &BTRFS_I(inode)->runtime_flags)); 5192 goto no_delete; 5193 } 5194 5195 if (inode->i_nlink > 0) { 5196 BUG_ON(btrfs_root_refs(&root->root_item) != 0 && 5197 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); 5198 goto no_delete; 5199 } 5200 5201 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode)); 5202 if (ret) { 5203 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5204 goto no_delete; 5205 } 5206 5207 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); 5208 if (!rsv) { 5209 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5210 goto no_delete; 5211 } 5212 rsv->size = min_size; 5213 rsv->failfast = 1; 5214 global_rsv = &fs_info->global_block_rsv; 5215 5216 btrfs_i_size_write(BTRFS_I(inode), 0); 5217 5218 /* 5219 * This is a bit simpler than btrfs_truncate since we've already 5220 * reserved our space for our orphan item in the unlink, so we just 5221 * need to reserve some slack space in case we add bytes and update 5222 * inode item when doing the truncate. 5223 */ 5224 while (1) { 5225 ret = btrfs_block_rsv_refill(root, rsv, min_size, 5226 BTRFS_RESERVE_FLUSH_LIMIT); 5227 5228 /* 5229 * Try and steal from the global reserve since we will 5230 * likely not use this space anyway, we want to try as 5231 * hard as possible to get this to work. 5232 */ 5233 if (ret) 5234 steal_from_global++; 5235 else 5236 steal_from_global = 0; 5237 ret = 0; 5238 5239 /* 5240 * steal_from_global == 0: we reserved stuff, hooray! 5241 * steal_from_global == 1: we didn't reserve stuff, boo! 5242 * steal_from_global == 2: we've committed, still not a lot of 5243 * room but maybe we'll have room in the global reserve this 5244 * time. 5245 * steal_from_global == 3: abandon all hope! 5246 */ 5247 if (steal_from_global > 2) { 5248 btrfs_warn(fs_info, 5249 "Could not get space for a delete, will truncate on mount %d", 5250 ret); 5251 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5252 btrfs_free_block_rsv(fs_info, rsv); 5253 goto no_delete; 5254 } 5255 5256 trans = btrfs_join_transaction(root); 5257 if (IS_ERR(trans)) { 5258 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5259 btrfs_free_block_rsv(fs_info, rsv); 5260 goto no_delete; 5261 } 5262 5263 /* 5264 * We can't just steal from the global reserve, we need to make 5265 * sure there is room to do it, if not we need to commit and try 5266 * again. 5267 */ 5268 if (steal_from_global) { 5269 if (!btrfs_check_space_for_delayed_refs(trans, fs_info)) 5270 ret = btrfs_block_rsv_migrate(global_rsv, rsv, 5271 min_size, 0); 5272 else 5273 ret = -ENOSPC; 5274 } 5275 5276 /* 5277 * Couldn't steal from the global reserve, we have too much 5278 * pending stuff built up, commit the transaction and try it 5279 * again. 5280 */ 5281 if (ret) { 5282 ret = btrfs_commit_transaction(trans); 5283 if (ret) { 5284 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5285 btrfs_free_block_rsv(fs_info, rsv); 5286 goto no_delete; 5287 } 5288 continue; 5289 } else { 5290 steal_from_global = 0; 5291 } 5292 5293 trans->block_rsv = rsv; 5294 5295 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 5296 if (ret != -ENOSPC && ret != -EAGAIN) 5297 break; 5298 5299 trans->block_rsv = &fs_info->trans_block_rsv; 5300 btrfs_end_transaction(trans); 5301 trans = NULL; 5302 btrfs_btree_balance_dirty(fs_info); 5303 } 5304 5305 btrfs_free_block_rsv(fs_info, rsv); 5306 5307 /* 5308 * Errors here aren't a big deal, it just means we leave orphan items 5309 * in the tree. They will be cleaned up on the next mount. 5310 */ 5311 if (ret == 0) { 5312 trans->block_rsv = root->orphan_block_rsv; 5313 btrfs_orphan_del(trans, BTRFS_I(inode)); 5314 } else { 5315 btrfs_orphan_del(NULL, BTRFS_I(inode)); 5316 } 5317 5318 trans->block_rsv = &fs_info->trans_block_rsv; 5319 if (!(root == fs_info->tree_root || 5320 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 5321 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode))); 5322 5323 btrfs_end_transaction(trans); 5324 btrfs_btree_balance_dirty(fs_info); 5325 no_delete: 5326 btrfs_remove_delayed_node(BTRFS_I(inode)); 5327 clear_inode(inode); 5328 } 5329 5330 /* 5331 * this returns the key found in the dir entry in the location pointer. 5332 * If no dir entries were found, location->objectid is 0. 5333 */ 5334 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 5335 struct btrfs_key *location) 5336 { 5337 const char *name = dentry->d_name.name; 5338 int namelen = dentry->d_name.len; 5339 struct btrfs_dir_item *di; 5340 struct btrfs_path *path; 5341 struct btrfs_root *root = BTRFS_I(dir)->root; 5342 int ret = 0; 5343 5344 path = btrfs_alloc_path(); 5345 if (!path) 5346 return -ENOMEM; 5347 5348 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)), 5349 name, namelen, 0); 5350 if (IS_ERR(di)) 5351 ret = PTR_ERR(di); 5352 5353 if (IS_ERR_OR_NULL(di)) 5354 goto out_err; 5355 5356 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 5357 out: 5358 btrfs_free_path(path); 5359 return ret; 5360 out_err: 5361 location->objectid = 0; 5362 goto out; 5363 } 5364 5365 /* 5366 * when we hit a tree root in a directory, the btrfs part of the inode 5367 * needs to be changed to reflect the root directory of the tree root. This 5368 * is kind of like crossing a mount point. 5369 */ 5370 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info, 5371 struct inode *dir, 5372 struct dentry *dentry, 5373 struct btrfs_key *location, 5374 struct btrfs_root **sub_root) 5375 { 5376 struct btrfs_path *path; 5377 struct btrfs_root *new_root; 5378 struct btrfs_root_ref *ref; 5379 struct extent_buffer *leaf; 5380 struct btrfs_key key; 5381 int ret; 5382 int err = 0; 5383 5384 path = btrfs_alloc_path(); 5385 if (!path) { 5386 err = -ENOMEM; 5387 goto out; 5388 } 5389 5390 err = -ENOENT; 5391 key.objectid = BTRFS_I(dir)->root->root_key.objectid; 5392 key.type = BTRFS_ROOT_REF_KEY; 5393 key.offset = location->objectid; 5394 5395 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0); 5396 if (ret) { 5397 if (ret < 0) 5398 err = ret; 5399 goto out; 5400 } 5401 5402 leaf = path->nodes[0]; 5403 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 5404 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) || 5405 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 5406 goto out; 5407 5408 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 5409 (unsigned long)(ref + 1), 5410 dentry->d_name.len); 5411 if (ret) 5412 goto out; 5413 5414 btrfs_release_path(path); 5415 5416 new_root = btrfs_read_fs_root_no_name(fs_info, location); 5417 if (IS_ERR(new_root)) { 5418 err = PTR_ERR(new_root); 5419 goto out; 5420 } 5421 5422 *sub_root = new_root; 5423 location->objectid = btrfs_root_dirid(&new_root->root_item); 5424 location->type = BTRFS_INODE_ITEM_KEY; 5425 location->offset = 0; 5426 err = 0; 5427 out: 5428 btrfs_free_path(path); 5429 return err; 5430 } 5431 5432 static void inode_tree_add(struct inode *inode) 5433 { 5434 struct btrfs_root *root = BTRFS_I(inode)->root; 5435 struct btrfs_inode *entry; 5436 struct rb_node **p; 5437 struct rb_node *parent; 5438 struct rb_node *new = &BTRFS_I(inode)->rb_node; 5439 u64 ino = btrfs_ino(BTRFS_I(inode)); 5440 5441 if (inode_unhashed(inode)) 5442 return; 5443 parent = NULL; 5444 spin_lock(&root->inode_lock); 5445 p = &root->inode_tree.rb_node; 5446 while (*p) { 5447 parent = *p; 5448 entry = rb_entry(parent, struct btrfs_inode, rb_node); 5449 5450 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode))) 5451 p = &parent->rb_left; 5452 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode))) 5453 p = &parent->rb_right; 5454 else { 5455 WARN_ON(!(entry->vfs_inode.i_state & 5456 (I_WILL_FREE | I_FREEING))); 5457 rb_replace_node(parent, new, &root->inode_tree); 5458 RB_CLEAR_NODE(parent); 5459 spin_unlock(&root->inode_lock); 5460 return; 5461 } 5462 } 5463 rb_link_node(new, parent, p); 5464 rb_insert_color(new, &root->inode_tree); 5465 spin_unlock(&root->inode_lock); 5466 } 5467 5468 static void inode_tree_del(struct inode *inode) 5469 { 5470 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 5471 struct btrfs_root *root = BTRFS_I(inode)->root; 5472 int empty = 0; 5473 5474 spin_lock(&root->inode_lock); 5475 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 5476 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 5477 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 5478 empty = RB_EMPTY_ROOT(&root->inode_tree); 5479 } 5480 spin_unlock(&root->inode_lock); 5481 5482 if (empty && btrfs_root_refs(&root->root_item) == 0) { 5483 synchronize_srcu(&fs_info->subvol_srcu); 5484 spin_lock(&root->inode_lock); 5485 empty = RB_EMPTY_ROOT(&root->inode_tree); 5486 spin_unlock(&root->inode_lock); 5487 if (empty) 5488 btrfs_add_dead_root(root); 5489 } 5490 } 5491 5492 void btrfs_invalidate_inodes(struct btrfs_root *root) 5493 { 5494 struct btrfs_fs_info *fs_info = root->fs_info; 5495 struct rb_node *node; 5496 struct rb_node *prev; 5497 struct btrfs_inode *entry; 5498 struct inode *inode; 5499 u64 objectid = 0; 5500 5501 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 5502 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 5503 5504 spin_lock(&root->inode_lock); 5505 again: 5506 node = root->inode_tree.rb_node; 5507 prev = NULL; 5508 while (node) { 5509 prev = node; 5510 entry = rb_entry(node, struct btrfs_inode, rb_node); 5511 5512 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode))) 5513 node = node->rb_left; 5514 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode))) 5515 node = node->rb_right; 5516 else 5517 break; 5518 } 5519 if (!node) { 5520 while (prev) { 5521 entry = rb_entry(prev, struct btrfs_inode, rb_node); 5522 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) { 5523 node = prev; 5524 break; 5525 } 5526 prev = rb_next(prev); 5527 } 5528 } 5529 while (node) { 5530 entry = rb_entry(node, struct btrfs_inode, rb_node); 5531 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1; 5532 inode = igrab(&entry->vfs_inode); 5533 if (inode) { 5534 spin_unlock(&root->inode_lock); 5535 if (atomic_read(&inode->i_count) > 1) 5536 d_prune_aliases(inode); 5537 /* 5538 * btrfs_drop_inode will have it removed from 5539 * the inode cache when its usage count 5540 * hits zero. 5541 */ 5542 iput(inode); 5543 cond_resched(); 5544 spin_lock(&root->inode_lock); 5545 goto again; 5546 } 5547 5548 if (cond_resched_lock(&root->inode_lock)) 5549 goto again; 5550 5551 node = rb_next(node); 5552 } 5553 spin_unlock(&root->inode_lock); 5554 } 5555 5556 static int btrfs_init_locked_inode(struct inode *inode, void *p) 5557 { 5558 struct btrfs_iget_args *args = p; 5559 inode->i_ino = args->location->objectid; 5560 memcpy(&BTRFS_I(inode)->location, args->location, 5561 sizeof(*args->location)); 5562 BTRFS_I(inode)->root = args->root; 5563 return 0; 5564 } 5565 5566 static int btrfs_find_actor(struct inode *inode, void *opaque) 5567 { 5568 struct btrfs_iget_args *args = opaque; 5569 return args->location->objectid == BTRFS_I(inode)->location.objectid && 5570 args->root == BTRFS_I(inode)->root; 5571 } 5572 5573 static struct inode *btrfs_iget_locked(struct super_block *s, 5574 struct btrfs_key *location, 5575 struct btrfs_root *root) 5576 { 5577 struct inode *inode; 5578 struct btrfs_iget_args args; 5579 unsigned long hashval = btrfs_inode_hash(location->objectid, root); 5580 5581 args.location = location; 5582 args.root = root; 5583 5584 inode = iget5_locked(s, hashval, btrfs_find_actor, 5585 btrfs_init_locked_inode, 5586 (void *)&args); 5587 return inode; 5588 } 5589 5590 /* Get an inode object given its location and corresponding root. 5591 * Returns in *is_new if the inode was read from disk 5592 */ 5593 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 5594 struct btrfs_root *root, int *new) 5595 { 5596 struct inode *inode; 5597 5598 inode = btrfs_iget_locked(s, location, root); 5599 if (!inode) 5600 return ERR_PTR(-ENOMEM); 5601 5602 if (inode->i_state & I_NEW) { 5603 int ret; 5604 5605 ret = btrfs_read_locked_inode(inode); 5606 if (!is_bad_inode(inode)) { 5607 inode_tree_add(inode); 5608 unlock_new_inode(inode); 5609 if (new) 5610 *new = 1; 5611 } else { 5612 unlock_new_inode(inode); 5613 iput(inode); 5614 ASSERT(ret < 0); 5615 inode = ERR_PTR(ret < 0 ? ret : -ESTALE); 5616 } 5617 } 5618 5619 return inode; 5620 } 5621 5622 static struct inode *new_simple_dir(struct super_block *s, 5623 struct btrfs_key *key, 5624 struct btrfs_root *root) 5625 { 5626 struct inode *inode = new_inode(s); 5627 5628 if (!inode) 5629 return ERR_PTR(-ENOMEM); 5630 5631 BTRFS_I(inode)->root = root; 5632 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 5633 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 5634 5635 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 5636 inode->i_op = &btrfs_dir_ro_inode_operations; 5637 inode->i_opflags &= ~IOP_XATTR; 5638 inode->i_fop = &simple_dir_operations; 5639 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 5640 inode->i_mtime = current_time(inode); 5641 inode->i_atime = inode->i_mtime; 5642 inode->i_ctime = inode->i_mtime; 5643 BTRFS_I(inode)->i_otime = inode->i_mtime; 5644 5645 return inode; 5646 } 5647 5648 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 5649 { 5650 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 5651 struct inode *inode; 5652 struct btrfs_root *root = BTRFS_I(dir)->root; 5653 struct btrfs_root *sub_root = root; 5654 struct btrfs_key location; 5655 int index; 5656 int ret = 0; 5657 5658 if (dentry->d_name.len > BTRFS_NAME_LEN) 5659 return ERR_PTR(-ENAMETOOLONG); 5660 5661 ret = btrfs_inode_by_name(dir, dentry, &location); 5662 if (ret < 0) 5663 return ERR_PTR(ret); 5664 5665 if (location.objectid == 0) 5666 return ERR_PTR(-ENOENT); 5667 5668 if (location.type == BTRFS_INODE_ITEM_KEY) { 5669 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 5670 return inode; 5671 } 5672 5673 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 5674 5675 index = srcu_read_lock(&fs_info->subvol_srcu); 5676 ret = fixup_tree_root_location(fs_info, dir, dentry, 5677 &location, &sub_root); 5678 if (ret < 0) { 5679 if (ret != -ENOENT) 5680 inode = ERR_PTR(ret); 5681 else 5682 inode = new_simple_dir(dir->i_sb, &location, sub_root); 5683 } else { 5684 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 5685 } 5686 srcu_read_unlock(&fs_info->subvol_srcu, index); 5687 5688 if (!IS_ERR(inode) && root != sub_root) { 5689 down_read(&fs_info->cleanup_work_sem); 5690 if (!(inode->i_sb->s_flags & MS_RDONLY)) 5691 ret = btrfs_orphan_cleanup(sub_root); 5692 up_read(&fs_info->cleanup_work_sem); 5693 if (ret) { 5694 iput(inode); 5695 inode = ERR_PTR(ret); 5696 } 5697 } 5698 5699 return inode; 5700 } 5701 5702 static int btrfs_dentry_delete(const struct dentry *dentry) 5703 { 5704 struct btrfs_root *root; 5705 struct inode *inode = d_inode(dentry); 5706 5707 if (!inode && !IS_ROOT(dentry)) 5708 inode = d_inode(dentry->d_parent); 5709 5710 if (inode) { 5711 root = BTRFS_I(inode)->root; 5712 if (btrfs_root_refs(&root->root_item) == 0) 5713 return 1; 5714 5715 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 5716 return 1; 5717 } 5718 return 0; 5719 } 5720 5721 static void btrfs_dentry_release(struct dentry *dentry) 5722 { 5723 kfree(dentry->d_fsdata); 5724 } 5725 5726 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5727 unsigned int flags) 5728 { 5729 struct inode *inode; 5730 5731 inode = btrfs_lookup_dentry(dir, dentry); 5732 if (IS_ERR(inode)) { 5733 if (PTR_ERR(inode) == -ENOENT) 5734 inode = NULL; 5735 else 5736 return ERR_CAST(inode); 5737 } 5738 5739 return d_splice_alias(inode, dentry); 5740 } 5741 5742 unsigned char btrfs_filetype_table[] = { 5743 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5744 }; 5745 5746 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) 5747 { 5748 struct inode *inode = file_inode(file); 5749 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 5750 struct btrfs_root *root = BTRFS_I(inode)->root; 5751 struct btrfs_item *item; 5752 struct btrfs_dir_item *di; 5753 struct btrfs_key key; 5754 struct btrfs_key found_key; 5755 struct btrfs_path *path; 5756 struct list_head ins_list; 5757 struct list_head del_list; 5758 int ret; 5759 struct extent_buffer *leaf; 5760 int slot; 5761 unsigned char d_type; 5762 int over = 0; 5763 char tmp_name[32]; 5764 char *name_ptr; 5765 int name_len; 5766 bool put = false; 5767 struct btrfs_key location; 5768 5769 if (!dir_emit_dots(file, ctx)) 5770 return 0; 5771 5772 path = btrfs_alloc_path(); 5773 if (!path) 5774 return -ENOMEM; 5775 5776 path->reada = READA_FORWARD; 5777 5778 INIT_LIST_HEAD(&ins_list); 5779 INIT_LIST_HEAD(&del_list); 5780 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list); 5781 5782 key.type = BTRFS_DIR_INDEX_KEY; 5783 key.offset = ctx->pos; 5784 key.objectid = btrfs_ino(BTRFS_I(inode)); 5785 5786 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5787 if (ret < 0) 5788 goto err; 5789 5790 while (1) { 5791 leaf = path->nodes[0]; 5792 slot = path->slots[0]; 5793 if (slot >= btrfs_header_nritems(leaf)) { 5794 ret = btrfs_next_leaf(root, path); 5795 if (ret < 0) 5796 goto err; 5797 else if (ret > 0) 5798 break; 5799 continue; 5800 } 5801 5802 item = btrfs_item_nr(slot); 5803 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5804 5805 if (found_key.objectid != key.objectid) 5806 break; 5807 if (found_key.type != BTRFS_DIR_INDEX_KEY) 5808 break; 5809 if (found_key.offset < ctx->pos) 5810 goto next; 5811 if (btrfs_should_delete_dir_index(&del_list, found_key.offset)) 5812 goto next; 5813 5814 ctx->pos = found_key.offset; 5815 5816 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5817 if (verify_dir_item(fs_info, leaf, di)) 5818 goto next; 5819 5820 name_len = btrfs_dir_name_len(leaf, di); 5821 if (name_len <= sizeof(tmp_name)) { 5822 name_ptr = tmp_name; 5823 } else { 5824 name_ptr = kmalloc(name_len, GFP_KERNEL); 5825 if (!name_ptr) { 5826 ret = -ENOMEM; 5827 goto err; 5828 } 5829 } 5830 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1), 5831 name_len); 5832 5833 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5834 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5835 5836 over = !dir_emit(ctx, name_ptr, name_len, location.objectid, 5837 d_type); 5838 5839 if (name_ptr != tmp_name) 5840 kfree(name_ptr); 5841 5842 if (over) 5843 goto nopos; 5844 ctx->pos++; 5845 next: 5846 path->slots[0]++; 5847 } 5848 5849 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); 5850 if (ret) 5851 goto nopos; 5852 5853 /* 5854 * Stop new entries from being returned after we return the last 5855 * entry. 5856 * 5857 * New directory entries are assigned a strictly increasing 5858 * offset. This means that new entries created during readdir 5859 * are *guaranteed* to be seen in the future by that readdir. 5860 * This has broken buggy programs which operate on names as 5861 * they're returned by readdir. Until we re-use freed offsets 5862 * we have this hack to stop new entries from being returned 5863 * under the assumption that they'll never reach this huge 5864 * offset. 5865 * 5866 * This is being careful not to overflow 32bit loff_t unless the 5867 * last entry requires it because doing so has broken 32bit apps 5868 * in the past. 5869 */ 5870 if (ctx->pos >= INT_MAX) 5871 ctx->pos = LLONG_MAX; 5872 else 5873 ctx->pos = INT_MAX; 5874 nopos: 5875 ret = 0; 5876 err: 5877 if (put) 5878 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list); 5879 btrfs_free_path(path); 5880 return ret; 5881 } 5882 5883 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5884 { 5885 struct btrfs_root *root = BTRFS_I(inode)->root; 5886 struct btrfs_trans_handle *trans; 5887 int ret = 0; 5888 bool nolock = false; 5889 5890 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5891 return 0; 5892 5893 if (btrfs_fs_closing(root->fs_info) && 5894 btrfs_is_free_space_inode(BTRFS_I(inode))) 5895 nolock = true; 5896 5897 if (wbc->sync_mode == WB_SYNC_ALL) { 5898 if (nolock) 5899 trans = btrfs_join_transaction_nolock(root); 5900 else 5901 trans = btrfs_join_transaction(root); 5902 if (IS_ERR(trans)) 5903 return PTR_ERR(trans); 5904 ret = btrfs_commit_transaction(trans); 5905 } 5906 return ret; 5907 } 5908 5909 /* 5910 * This is somewhat expensive, updating the tree every time the 5911 * inode changes. But, it is most likely to find the inode in cache. 5912 * FIXME, needs more benchmarking...there are no reasons other than performance 5913 * to keep or drop this code. 5914 */ 5915 static int btrfs_dirty_inode(struct inode *inode) 5916 { 5917 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 5918 struct btrfs_root *root = BTRFS_I(inode)->root; 5919 struct btrfs_trans_handle *trans; 5920 int ret; 5921 5922 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5923 return 0; 5924 5925 trans = btrfs_join_transaction(root); 5926 if (IS_ERR(trans)) 5927 return PTR_ERR(trans); 5928 5929 ret = btrfs_update_inode(trans, root, inode); 5930 if (ret && ret == -ENOSPC) { 5931 /* whoops, lets try again with the full transaction */ 5932 btrfs_end_transaction(trans); 5933 trans = btrfs_start_transaction(root, 1); 5934 if (IS_ERR(trans)) 5935 return PTR_ERR(trans); 5936 5937 ret = btrfs_update_inode(trans, root, inode); 5938 } 5939 btrfs_end_transaction(trans); 5940 if (BTRFS_I(inode)->delayed_node) 5941 btrfs_balance_delayed_items(fs_info); 5942 5943 return ret; 5944 } 5945 5946 /* 5947 * This is a copy of file_update_time. We need this so we can return error on 5948 * ENOSPC for updating the inode in the case of file write and mmap writes. 5949 */ 5950 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5951 int flags) 5952 { 5953 struct btrfs_root *root = BTRFS_I(inode)->root; 5954 5955 if (btrfs_root_readonly(root)) 5956 return -EROFS; 5957 5958 if (flags & S_VERSION) 5959 inode_inc_iversion(inode); 5960 if (flags & S_CTIME) 5961 inode->i_ctime = *now; 5962 if (flags & S_MTIME) 5963 inode->i_mtime = *now; 5964 if (flags & S_ATIME) 5965 inode->i_atime = *now; 5966 return btrfs_dirty_inode(inode); 5967 } 5968 5969 /* 5970 * find the highest existing sequence number in a directory 5971 * and then set the in-memory index_cnt variable to reflect 5972 * free sequence numbers 5973 */ 5974 static int btrfs_set_inode_index_count(struct btrfs_inode *inode) 5975 { 5976 struct btrfs_root *root = inode->root; 5977 struct btrfs_key key, found_key; 5978 struct btrfs_path *path; 5979 struct extent_buffer *leaf; 5980 int ret; 5981 5982 key.objectid = btrfs_ino(inode); 5983 key.type = BTRFS_DIR_INDEX_KEY; 5984 key.offset = (u64)-1; 5985 5986 path = btrfs_alloc_path(); 5987 if (!path) 5988 return -ENOMEM; 5989 5990 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5991 if (ret < 0) 5992 goto out; 5993 /* FIXME: we should be able to handle this */ 5994 if (ret == 0) 5995 goto out; 5996 ret = 0; 5997 5998 /* 5999 * MAGIC NUMBER EXPLANATION: 6000 * since we search a directory based on f_pos we have to start at 2 6001 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 6002 * else has to start at 2 6003 */ 6004 if (path->slots[0] == 0) { 6005 inode->index_cnt = 2; 6006 goto out; 6007 } 6008 6009 path->slots[0]--; 6010 6011 leaf = path->nodes[0]; 6012 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6013 6014 if (found_key.objectid != btrfs_ino(inode) || 6015 found_key.type != BTRFS_DIR_INDEX_KEY) { 6016 inode->index_cnt = 2; 6017 goto out; 6018 } 6019 6020 inode->index_cnt = found_key.offset + 1; 6021 out: 6022 btrfs_free_path(path); 6023 return ret; 6024 } 6025 6026 /* 6027 * helper to find a free sequence number in a given directory. This current 6028 * code is very simple, later versions will do smarter things in the btree 6029 */ 6030 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index) 6031 { 6032 int ret = 0; 6033 6034 if (dir->index_cnt == (u64)-1) { 6035 ret = btrfs_inode_delayed_dir_index_count(dir); 6036 if (ret) { 6037 ret = btrfs_set_inode_index_count(dir); 6038 if (ret) 6039 return ret; 6040 } 6041 } 6042 6043 *index = dir->index_cnt; 6044 dir->index_cnt++; 6045 6046 return ret; 6047 } 6048 6049 static int btrfs_insert_inode_locked(struct inode *inode) 6050 { 6051 struct btrfs_iget_args args; 6052 args.location = &BTRFS_I(inode)->location; 6053 args.root = BTRFS_I(inode)->root; 6054 6055 return insert_inode_locked4(inode, 6056 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root), 6057 btrfs_find_actor, &args); 6058 } 6059 6060 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 6061 struct btrfs_root *root, 6062 struct inode *dir, 6063 const char *name, int name_len, 6064 u64 ref_objectid, u64 objectid, 6065 umode_t mode, u64 *index) 6066 { 6067 struct btrfs_fs_info *fs_info = root->fs_info; 6068 struct inode *inode; 6069 struct btrfs_inode_item *inode_item; 6070 struct btrfs_key *location; 6071 struct btrfs_path *path; 6072 struct btrfs_inode_ref *ref; 6073 struct btrfs_key key[2]; 6074 u32 sizes[2]; 6075 int nitems = name ? 2 : 1; 6076 unsigned long ptr; 6077 int ret; 6078 6079 path = btrfs_alloc_path(); 6080 if (!path) 6081 return ERR_PTR(-ENOMEM); 6082 6083 inode = new_inode(fs_info->sb); 6084 if (!inode) { 6085 btrfs_free_path(path); 6086 return ERR_PTR(-ENOMEM); 6087 } 6088 6089 /* 6090 * O_TMPFILE, set link count to 0, so that after this point, 6091 * we fill in an inode item with the correct link count. 6092 */ 6093 if (!name) 6094 set_nlink(inode, 0); 6095 6096 /* 6097 * we have to initialize this early, so we can reclaim the inode 6098 * number if we fail afterwards in this function. 6099 */ 6100 inode->i_ino = objectid; 6101 6102 if (dir && name) { 6103 trace_btrfs_inode_request(dir); 6104 6105 ret = btrfs_set_inode_index(BTRFS_I(dir), index); 6106 if (ret) { 6107 btrfs_free_path(path); 6108 iput(inode); 6109 return ERR_PTR(ret); 6110 } 6111 } else if (dir) { 6112 *index = 0; 6113 } 6114 /* 6115 * index_cnt is ignored for everything but a dir, 6116 * btrfs_get_inode_index_count has an explanation for the magic 6117 * number 6118 */ 6119 BTRFS_I(inode)->index_cnt = 2; 6120 BTRFS_I(inode)->dir_index = *index; 6121 BTRFS_I(inode)->root = root; 6122 BTRFS_I(inode)->generation = trans->transid; 6123 inode->i_generation = BTRFS_I(inode)->generation; 6124 6125 /* 6126 * We could have gotten an inode number from somebody who was fsynced 6127 * and then removed in this same transaction, so let's just set full 6128 * sync since it will be a full sync anyway and this will blow away the 6129 * old info in the log. 6130 */ 6131 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 6132 6133 key[0].objectid = objectid; 6134 key[0].type = BTRFS_INODE_ITEM_KEY; 6135 key[0].offset = 0; 6136 6137 sizes[0] = sizeof(struct btrfs_inode_item); 6138 6139 if (name) { 6140 /* 6141 * Start new inodes with an inode_ref. This is slightly more 6142 * efficient for small numbers of hard links since they will 6143 * be packed into one item. Extended refs will kick in if we 6144 * add more hard links than can fit in the ref item. 6145 */ 6146 key[1].objectid = objectid; 6147 key[1].type = BTRFS_INODE_REF_KEY; 6148 key[1].offset = ref_objectid; 6149 6150 sizes[1] = name_len + sizeof(*ref); 6151 } 6152 6153 location = &BTRFS_I(inode)->location; 6154 location->objectid = objectid; 6155 location->offset = 0; 6156 location->type = BTRFS_INODE_ITEM_KEY; 6157 6158 ret = btrfs_insert_inode_locked(inode); 6159 if (ret < 0) 6160 goto fail; 6161 6162 path->leave_spinning = 1; 6163 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems); 6164 if (ret != 0) 6165 goto fail_unlock; 6166 6167 inode_init_owner(inode, dir, mode); 6168 inode_set_bytes(inode, 0); 6169 6170 inode->i_mtime = current_time(inode); 6171 inode->i_atime = inode->i_mtime; 6172 inode->i_ctime = inode->i_mtime; 6173 BTRFS_I(inode)->i_otime = inode->i_mtime; 6174 6175 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 6176 struct btrfs_inode_item); 6177 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item, 6178 sizeof(*inode_item)); 6179 fill_inode_item(trans, path->nodes[0], inode_item, inode); 6180 6181 if (name) { 6182 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 6183 struct btrfs_inode_ref); 6184 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 6185 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 6186 ptr = (unsigned long)(ref + 1); 6187 write_extent_buffer(path->nodes[0], name, ptr, name_len); 6188 } 6189 6190 btrfs_mark_buffer_dirty(path->nodes[0]); 6191 btrfs_free_path(path); 6192 6193 btrfs_inherit_iflags(inode, dir); 6194 6195 if (S_ISREG(mode)) { 6196 if (btrfs_test_opt(fs_info, NODATASUM)) 6197 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 6198 if (btrfs_test_opt(fs_info, NODATACOW)) 6199 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 6200 BTRFS_INODE_NODATASUM; 6201 } 6202 6203 inode_tree_add(inode); 6204 6205 trace_btrfs_inode_new(inode); 6206 btrfs_set_inode_last_trans(trans, inode); 6207 6208 btrfs_update_root_times(trans, root); 6209 6210 ret = btrfs_inode_inherit_props(trans, inode, dir); 6211 if (ret) 6212 btrfs_err(fs_info, 6213 "error inheriting props for ino %llu (root %llu): %d", 6214 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret); 6215 6216 return inode; 6217 6218 fail_unlock: 6219 unlock_new_inode(inode); 6220 fail: 6221 if (dir && name) 6222 BTRFS_I(dir)->index_cnt--; 6223 btrfs_free_path(path); 6224 iput(inode); 6225 return ERR_PTR(ret); 6226 } 6227 6228 static inline u8 btrfs_inode_type(struct inode *inode) 6229 { 6230 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 6231 } 6232 6233 /* 6234 * utility function to add 'inode' into 'parent_inode' with 6235 * a give name and a given sequence number. 6236 * if 'add_backref' is true, also insert a backref from the 6237 * inode to the parent directory. 6238 */ 6239 int btrfs_add_link(struct btrfs_trans_handle *trans, 6240 struct btrfs_inode *parent_inode, struct btrfs_inode *inode, 6241 const char *name, int name_len, int add_backref, u64 index) 6242 { 6243 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); 6244 int ret = 0; 6245 struct btrfs_key key; 6246 struct btrfs_root *root = parent_inode->root; 6247 u64 ino = btrfs_ino(inode); 6248 u64 parent_ino = btrfs_ino(parent_inode); 6249 6250 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6251 memcpy(&key, &inode->root->root_key, sizeof(key)); 6252 } else { 6253 key.objectid = ino; 6254 key.type = BTRFS_INODE_ITEM_KEY; 6255 key.offset = 0; 6256 } 6257 6258 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6259 ret = btrfs_add_root_ref(trans, fs_info, key.objectid, 6260 root->root_key.objectid, parent_ino, 6261 index, name, name_len); 6262 } else if (add_backref) { 6263 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 6264 parent_ino, index); 6265 } 6266 6267 /* Nothing to clean up yet */ 6268 if (ret) 6269 return ret; 6270 6271 ret = btrfs_insert_dir_item(trans, root, name, name_len, 6272 parent_inode, &key, 6273 btrfs_inode_type(&inode->vfs_inode), index); 6274 if (ret == -EEXIST || ret == -EOVERFLOW) 6275 goto fail_dir_item; 6276 else if (ret) { 6277 btrfs_abort_transaction(trans, ret); 6278 return ret; 6279 } 6280 6281 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size + 6282 name_len * 2); 6283 inode_inc_iversion(&parent_inode->vfs_inode); 6284 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime = 6285 current_time(&parent_inode->vfs_inode); 6286 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode); 6287 if (ret) 6288 btrfs_abort_transaction(trans, ret); 6289 return ret; 6290 6291 fail_dir_item: 6292 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6293 u64 local_index; 6294 int err; 6295 err = btrfs_del_root_ref(trans, fs_info, key.objectid, 6296 root->root_key.objectid, parent_ino, 6297 &local_index, name, name_len); 6298 6299 } else if (add_backref) { 6300 u64 local_index; 6301 int err; 6302 6303 err = btrfs_del_inode_ref(trans, root, name, name_len, 6304 ino, parent_ino, &local_index); 6305 } 6306 return ret; 6307 } 6308 6309 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 6310 struct btrfs_inode *dir, struct dentry *dentry, 6311 struct btrfs_inode *inode, int backref, u64 index) 6312 { 6313 int err = btrfs_add_link(trans, dir, inode, 6314 dentry->d_name.name, dentry->d_name.len, 6315 backref, index); 6316 if (err > 0) 6317 err = -EEXIST; 6318 return err; 6319 } 6320 6321 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 6322 umode_t mode, dev_t rdev) 6323 { 6324 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 6325 struct btrfs_trans_handle *trans; 6326 struct btrfs_root *root = BTRFS_I(dir)->root; 6327 struct inode *inode = NULL; 6328 int err; 6329 int drop_inode = 0; 6330 u64 objectid; 6331 u64 index = 0; 6332 6333 /* 6334 * 2 for inode item and ref 6335 * 2 for dir items 6336 * 1 for xattr if selinux is on 6337 */ 6338 trans = btrfs_start_transaction(root, 5); 6339 if (IS_ERR(trans)) 6340 return PTR_ERR(trans); 6341 6342 err = btrfs_find_free_ino(root, &objectid); 6343 if (err) 6344 goto out_unlock; 6345 6346 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6347 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid, 6348 mode, &index); 6349 if (IS_ERR(inode)) { 6350 err = PTR_ERR(inode); 6351 goto out_unlock; 6352 } 6353 6354 /* 6355 * If the active LSM wants to access the inode during 6356 * d_instantiate it needs these. Smack checks to see 6357 * if the filesystem supports xattrs by looking at the 6358 * ops vector. 6359 */ 6360 inode->i_op = &btrfs_special_inode_operations; 6361 init_special_inode(inode, inode->i_mode, rdev); 6362 6363 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6364 if (err) 6365 goto out_unlock_inode; 6366 6367 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode), 6368 0, index); 6369 if (err) { 6370 goto out_unlock_inode; 6371 } else { 6372 btrfs_update_inode(trans, root, inode); 6373 unlock_new_inode(inode); 6374 d_instantiate(dentry, inode); 6375 } 6376 6377 out_unlock: 6378 btrfs_end_transaction(trans); 6379 btrfs_balance_delayed_items(fs_info); 6380 btrfs_btree_balance_dirty(fs_info); 6381 if (drop_inode) { 6382 inode_dec_link_count(inode); 6383 iput(inode); 6384 } 6385 return err; 6386 6387 out_unlock_inode: 6388 drop_inode = 1; 6389 unlock_new_inode(inode); 6390 goto out_unlock; 6391 6392 } 6393 6394 static int btrfs_create(struct inode *dir, struct dentry *dentry, 6395 umode_t mode, bool excl) 6396 { 6397 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 6398 struct btrfs_trans_handle *trans; 6399 struct btrfs_root *root = BTRFS_I(dir)->root; 6400 struct inode *inode = NULL; 6401 int drop_inode_on_err = 0; 6402 int err; 6403 u64 objectid; 6404 u64 index = 0; 6405 6406 /* 6407 * 2 for inode item and ref 6408 * 2 for dir items 6409 * 1 for xattr if selinux is on 6410 */ 6411 trans = btrfs_start_transaction(root, 5); 6412 if (IS_ERR(trans)) 6413 return PTR_ERR(trans); 6414 6415 err = btrfs_find_free_ino(root, &objectid); 6416 if (err) 6417 goto out_unlock; 6418 6419 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6420 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid, 6421 mode, &index); 6422 if (IS_ERR(inode)) { 6423 err = PTR_ERR(inode); 6424 goto out_unlock; 6425 } 6426 drop_inode_on_err = 1; 6427 /* 6428 * If the active LSM wants to access the inode during 6429 * d_instantiate it needs these. Smack checks to see 6430 * if the filesystem supports xattrs by looking at the 6431 * ops vector. 6432 */ 6433 inode->i_fop = &btrfs_file_operations; 6434 inode->i_op = &btrfs_file_inode_operations; 6435 inode->i_mapping->a_ops = &btrfs_aops; 6436 6437 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6438 if (err) 6439 goto out_unlock_inode; 6440 6441 err = btrfs_update_inode(trans, root, inode); 6442 if (err) 6443 goto out_unlock_inode; 6444 6445 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode), 6446 0, index); 6447 if (err) 6448 goto out_unlock_inode; 6449 6450 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 6451 unlock_new_inode(inode); 6452 d_instantiate(dentry, inode); 6453 6454 out_unlock: 6455 btrfs_end_transaction(trans); 6456 if (err && drop_inode_on_err) { 6457 inode_dec_link_count(inode); 6458 iput(inode); 6459 } 6460 btrfs_balance_delayed_items(fs_info); 6461 btrfs_btree_balance_dirty(fs_info); 6462 return err; 6463 6464 out_unlock_inode: 6465 unlock_new_inode(inode); 6466 goto out_unlock; 6467 6468 } 6469 6470 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 6471 struct dentry *dentry) 6472 { 6473 struct btrfs_trans_handle *trans = NULL; 6474 struct btrfs_root *root = BTRFS_I(dir)->root; 6475 struct inode *inode = d_inode(old_dentry); 6476 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 6477 u64 index; 6478 int err; 6479 int drop_inode = 0; 6480 6481 /* do not allow sys_link's with other subvols of the same device */ 6482 if (root->objectid != BTRFS_I(inode)->root->objectid) 6483 return -EXDEV; 6484 6485 if (inode->i_nlink >= BTRFS_LINK_MAX) 6486 return -EMLINK; 6487 6488 err = btrfs_set_inode_index(BTRFS_I(dir), &index); 6489 if (err) 6490 goto fail; 6491 6492 /* 6493 * 2 items for inode and inode ref 6494 * 2 items for dir items 6495 * 1 item for parent inode 6496 */ 6497 trans = btrfs_start_transaction(root, 5); 6498 if (IS_ERR(trans)) { 6499 err = PTR_ERR(trans); 6500 trans = NULL; 6501 goto fail; 6502 } 6503 6504 /* There are several dir indexes for this inode, clear the cache. */ 6505 BTRFS_I(inode)->dir_index = 0ULL; 6506 inc_nlink(inode); 6507 inode_inc_iversion(inode); 6508 inode->i_ctime = current_time(inode); 6509 ihold(inode); 6510 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 6511 6512 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode), 6513 1, index); 6514 6515 if (err) { 6516 drop_inode = 1; 6517 } else { 6518 struct dentry *parent = dentry->d_parent; 6519 err = btrfs_update_inode(trans, root, inode); 6520 if (err) 6521 goto fail; 6522 if (inode->i_nlink == 1) { 6523 /* 6524 * If new hard link count is 1, it's a file created 6525 * with open(2) O_TMPFILE flag. 6526 */ 6527 err = btrfs_orphan_del(trans, BTRFS_I(inode)); 6528 if (err) 6529 goto fail; 6530 } 6531 d_instantiate(dentry, inode); 6532 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent); 6533 } 6534 6535 btrfs_balance_delayed_items(fs_info); 6536 fail: 6537 if (trans) 6538 btrfs_end_transaction(trans); 6539 if (drop_inode) { 6540 inode_dec_link_count(inode); 6541 iput(inode); 6542 } 6543 btrfs_btree_balance_dirty(fs_info); 6544 return err; 6545 } 6546 6547 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 6548 { 6549 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 6550 struct inode *inode = NULL; 6551 struct btrfs_trans_handle *trans; 6552 struct btrfs_root *root = BTRFS_I(dir)->root; 6553 int err = 0; 6554 int drop_on_err = 0; 6555 u64 objectid = 0; 6556 u64 index = 0; 6557 6558 /* 6559 * 2 items for inode and ref 6560 * 2 items for dir items 6561 * 1 for xattr if selinux is on 6562 */ 6563 trans = btrfs_start_transaction(root, 5); 6564 if (IS_ERR(trans)) 6565 return PTR_ERR(trans); 6566 6567 err = btrfs_find_free_ino(root, &objectid); 6568 if (err) 6569 goto out_fail; 6570 6571 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6572 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid, 6573 S_IFDIR | mode, &index); 6574 if (IS_ERR(inode)) { 6575 err = PTR_ERR(inode); 6576 goto out_fail; 6577 } 6578 6579 drop_on_err = 1; 6580 /* these must be set before we unlock the inode */ 6581 inode->i_op = &btrfs_dir_inode_operations; 6582 inode->i_fop = &btrfs_dir_file_operations; 6583 6584 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6585 if (err) 6586 goto out_fail_inode; 6587 6588 btrfs_i_size_write(BTRFS_I(inode), 0); 6589 err = btrfs_update_inode(trans, root, inode); 6590 if (err) 6591 goto out_fail_inode; 6592 6593 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), 6594 dentry->d_name.name, 6595 dentry->d_name.len, 0, index); 6596 if (err) 6597 goto out_fail_inode; 6598 6599 d_instantiate(dentry, inode); 6600 /* 6601 * mkdir is special. We're unlocking after we call d_instantiate 6602 * to avoid a race with nfsd calling d_instantiate. 6603 */ 6604 unlock_new_inode(inode); 6605 drop_on_err = 0; 6606 6607 out_fail: 6608 btrfs_end_transaction(trans); 6609 if (drop_on_err) { 6610 inode_dec_link_count(inode); 6611 iput(inode); 6612 } 6613 btrfs_balance_delayed_items(fs_info); 6614 btrfs_btree_balance_dirty(fs_info); 6615 return err; 6616 6617 out_fail_inode: 6618 unlock_new_inode(inode); 6619 goto out_fail; 6620 } 6621 6622 /* Find next extent map of a given extent map, caller needs to ensure locks */ 6623 static struct extent_map *next_extent_map(struct extent_map *em) 6624 { 6625 struct rb_node *next; 6626 6627 next = rb_next(&em->rb_node); 6628 if (!next) 6629 return NULL; 6630 return container_of(next, struct extent_map, rb_node); 6631 } 6632 6633 static struct extent_map *prev_extent_map(struct extent_map *em) 6634 { 6635 struct rb_node *prev; 6636 6637 prev = rb_prev(&em->rb_node); 6638 if (!prev) 6639 return NULL; 6640 return container_of(prev, struct extent_map, rb_node); 6641 } 6642 6643 /* helper for btfs_get_extent. Given an existing extent in the tree, 6644 * the existing extent is the nearest extent to map_start, 6645 * and an extent that you want to insert, deal with overlap and insert 6646 * the best fitted new extent into the tree. 6647 */ 6648 static int merge_extent_mapping(struct extent_map_tree *em_tree, 6649 struct extent_map *existing, 6650 struct extent_map *em, 6651 u64 map_start) 6652 { 6653 struct extent_map *prev; 6654 struct extent_map *next; 6655 u64 start; 6656 u64 end; 6657 u64 start_diff; 6658 6659 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 6660 6661 if (existing->start > map_start) { 6662 next = existing; 6663 prev = prev_extent_map(next); 6664 } else { 6665 prev = existing; 6666 next = next_extent_map(prev); 6667 } 6668 6669 start = prev ? extent_map_end(prev) : em->start; 6670 start = max_t(u64, start, em->start); 6671 end = next ? next->start : extent_map_end(em); 6672 end = min_t(u64, end, extent_map_end(em)); 6673 start_diff = start - em->start; 6674 em->start = start; 6675 em->len = end - start; 6676 if (em->block_start < EXTENT_MAP_LAST_BYTE && 6677 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 6678 em->block_start += start_diff; 6679 em->block_len -= start_diff; 6680 } 6681 return add_extent_mapping(em_tree, em, 0); 6682 } 6683 6684 static noinline int uncompress_inline(struct btrfs_path *path, 6685 struct page *page, 6686 size_t pg_offset, u64 extent_offset, 6687 struct btrfs_file_extent_item *item) 6688 { 6689 int ret; 6690 struct extent_buffer *leaf = path->nodes[0]; 6691 char *tmp; 6692 size_t max_size; 6693 unsigned long inline_size; 6694 unsigned long ptr; 6695 int compress_type; 6696 6697 WARN_ON(pg_offset != 0); 6698 compress_type = btrfs_file_extent_compression(leaf, item); 6699 max_size = btrfs_file_extent_ram_bytes(leaf, item); 6700 inline_size = btrfs_file_extent_inline_item_len(leaf, 6701 btrfs_item_nr(path->slots[0])); 6702 tmp = kmalloc(inline_size, GFP_NOFS); 6703 if (!tmp) 6704 return -ENOMEM; 6705 ptr = btrfs_file_extent_inline_start(item); 6706 6707 read_extent_buffer(leaf, tmp, ptr, inline_size); 6708 6709 max_size = min_t(unsigned long, PAGE_SIZE, max_size); 6710 ret = btrfs_decompress(compress_type, tmp, page, 6711 extent_offset, inline_size, max_size); 6712 6713 /* 6714 * decompression code contains a memset to fill in any space between the end 6715 * of the uncompressed data and the end of max_size in case the decompressed 6716 * data ends up shorter than ram_bytes. That doesn't cover the hole between 6717 * the end of an inline extent and the beginning of the next block, so we 6718 * cover that region here. 6719 */ 6720 6721 if (max_size + pg_offset < PAGE_SIZE) { 6722 char *map = kmap(page); 6723 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset); 6724 kunmap(page); 6725 } 6726 kfree(tmp); 6727 return ret; 6728 } 6729 6730 /* 6731 * a bit scary, this does extent mapping from logical file offset to the disk. 6732 * the ugly parts come from merging extents from the disk with the in-ram 6733 * representation. This gets more complex because of the data=ordered code, 6734 * where the in-ram extents might be locked pending data=ordered completion. 6735 * 6736 * This also copies inline extents directly into the page. 6737 */ 6738 6739 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, 6740 struct page *page, 6741 size_t pg_offset, u64 start, u64 len, 6742 int create) 6743 { 6744 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); 6745 int ret; 6746 int err = 0; 6747 u64 extent_start = 0; 6748 u64 extent_end = 0; 6749 u64 objectid = btrfs_ino(inode); 6750 u32 found_type; 6751 struct btrfs_path *path = NULL; 6752 struct btrfs_root *root = inode->root; 6753 struct btrfs_file_extent_item *item; 6754 struct extent_buffer *leaf; 6755 struct btrfs_key found_key; 6756 struct extent_map *em = NULL; 6757 struct extent_map_tree *em_tree = &inode->extent_tree; 6758 struct extent_io_tree *io_tree = &inode->io_tree; 6759 struct btrfs_trans_handle *trans = NULL; 6760 const bool new_inline = !page || create; 6761 6762 again: 6763 read_lock(&em_tree->lock); 6764 em = lookup_extent_mapping(em_tree, start, len); 6765 if (em) 6766 em->bdev = fs_info->fs_devices->latest_bdev; 6767 read_unlock(&em_tree->lock); 6768 6769 if (em) { 6770 if (em->start > start || em->start + em->len <= start) 6771 free_extent_map(em); 6772 else if (em->block_start == EXTENT_MAP_INLINE && page) 6773 free_extent_map(em); 6774 else 6775 goto out; 6776 } 6777 em = alloc_extent_map(); 6778 if (!em) { 6779 err = -ENOMEM; 6780 goto out; 6781 } 6782 em->bdev = fs_info->fs_devices->latest_bdev; 6783 em->start = EXTENT_MAP_HOLE; 6784 em->orig_start = EXTENT_MAP_HOLE; 6785 em->len = (u64)-1; 6786 em->block_len = (u64)-1; 6787 6788 if (!path) { 6789 path = btrfs_alloc_path(); 6790 if (!path) { 6791 err = -ENOMEM; 6792 goto out; 6793 } 6794 /* 6795 * Chances are we'll be called again, so go ahead and do 6796 * readahead 6797 */ 6798 path->reada = READA_FORWARD; 6799 } 6800 6801 ret = btrfs_lookup_file_extent(trans, root, path, 6802 objectid, start, trans != NULL); 6803 if (ret < 0) { 6804 err = ret; 6805 goto out; 6806 } 6807 6808 if (ret != 0) { 6809 if (path->slots[0] == 0) 6810 goto not_found; 6811 path->slots[0]--; 6812 } 6813 6814 leaf = path->nodes[0]; 6815 item = btrfs_item_ptr(leaf, path->slots[0], 6816 struct btrfs_file_extent_item); 6817 /* are we inside the extent that was found? */ 6818 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6819 found_type = found_key.type; 6820 if (found_key.objectid != objectid || 6821 found_type != BTRFS_EXTENT_DATA_KEY) { 6822 /* 6823 * If we backup past the first extent we want to move forward 6824 * and see if there is an extent in front of us, otherwise we'll 6825 * say there is a hole for our whole search range which can 6826 * cause problems. 6827 */ 6828 extent_end = start; 6829 goto next; 6830 } 6831 6832 found_type = btrfs_file_extent_type(leaf, item); 6833 extent_start = found_key.offset; 6834 if (found_type == BTRFS_FILE_EXTENT_REG || 6835 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6836 extent_end = extent_start + 6837 btrfs_file_extent_num_bytes(leaf, item); 6838 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6839 size_t size; 6840 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6841 extent_end = ALIGN(extent_start + size, 6842 fs_info->sectorsize); 6843 } 6844 next: 6845 if (start >= extent_end) { 6846 path->slots[0]++; 6847 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6848 ret = btrfs_next_leaf(root, path); 6849 if (ret < 0) { 6850 err = ret; 6851 goto out; 6852 } 6853 if (ret > 0) 6854 goto not_found; 6855 leaf = path->nodes[0]; 6856 } 6857 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6858 if (found_key.objectid != objectid || 6859 found_key.type != BTRFS_EXTENT_DATA_KEY) 6860 goto not_found; 6861 if (start + len <= found_key.offset) 6862 goto not_found; 6863 if (start > found_key.offset) 6864 goto next; 6865 em->start = start; 6866 em->orig_start = start; 6867 em->len = found_key.offset - start; 6868 goto not_found_em; 6869 } 6870 6871 btrfs_extent_item_to_extent_map(inode, path, item, 6872 new_inline, em); 6873 6874 if (found_type == BTRFS_FILE_EXTENT_REG || 6875 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6876 goto insert; 6877 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6878 unsigned long ptr; 6879 char *map; 6880 size_t size; 6881 size_t extent_offset; 6882 size_t copy_size; 6883 6884 if (new_inline) 6885 goto out; 6886 6887 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6888 extent_offset = page_offset(page) + pg_offset - extent_start; 6889 copy_size = min_t(u64, PAGE_SIZE - pg_offset, 6890 size - extent_offset); 6891 em->start = extent_start + extent_offset; 6892 em->len = ALIGN(copy_size, fs_info->sectorsize); 6893 em->orig_block_len = em->len; 6894 em->orig_start = em->start; 6895 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6896 if (create == 0 && !PageUptodate(page)) { 6897 if (btrfs_file_extent_compression(leaf, item) != 6898 BTRFS_COMPRESS_NONE) { 6899 ret = uncompress_inline(path, page, pg_offset, 6900 extent_offset, item); 6901 if (ret) { 6902 err = ret; 6903 goto out; 6904 } 6905 } else { 6906 map = kmap(page); 6907 read_extent_buffer(leaf, map + pg_offset, ptr, 6908 copy_size); 6909 if (pg_offset + copy_size < PAGE_SIZE) { 6910 memset(map + pg_offset + copy_size, 0, 6911 PAGE_SIZE - pg_offset - 6912 copy_size); 6913 } 6914 kunmap(page); 6915 } 6916 flush_dcache_page(page); 6917 } else if (create && PageUptodate(page)) { 6918 BUG(); 6919 if (!trans) { 6920 kunmap(page); 6921 free_extent_map(em); 6922 em = NULL; 6923 6924 btrfs_release_path(path); 6925 trans = btrfs_join_transaction(root); 6926 6927 if (IS_ERR(trans)) 6928 return ERR_CAST(trans); 6929 goto again; 6930 } 6931 map = kmap(page); 6932 write_extent_buffer(leaf, map + pg_offset, ptr, 6933 copy_size); 6934 kunmap(page); 6935 btrfs_mark_buffer_dirty(leaf); 6936 } 6937 set_extent_uptodate(io_tree, em->start, 6938 extent_map_end(em) - 1, NULL, GFP_NOFS); 6939 goto insert; 6940 } 6941 not_found: 6942 em->start = start; 6943 em->orig_start = start; 6944 em->len = len; 6945 not_found_em: 6946 em->block_start = EXTENT_MAP_HOLE; 6947 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6948 insert: 6949 btrfs_release_path(path); 6950 if (em->start > start || extent_map_end(em) <= start) { 6951 btrfs_err(fs_info, 6952 "bad extent! em: [%llu %llu] passed [%llu %llu]", 6953 em->start, em->len, start, len); 6954 err = -EIO; 6955 goto out; 6956 } 6957 6958 err = 0; 6959 write_lock(&em_tree->lock); 6960 ret = add_extent_mapping(em_tree, em, 0); 6961 /* it is possible that someone inserted the extent into the tree 6962 * while we had the lock dropped. It is also possible that 6963 * an overlapping map exists in the tree 6964 */ 6965 if (ret == -EEXIST) { 6966 struct extent_map *existing; 6967 6968 ret = 0; 6969 6970 existing = search_extent_mapping(em_tree, start, len); 6971 /* 6972 * existing will always be non-NULL, since there must be 6973 * extent causing the -EEXIST. 6974 */ 6975 if (existing->start == em->start && 6976 extent_map_end(existing) >= extent_map_end(em) && 6977 em->block_start == existing->block_start) { 6978 /* 6979 * The existing extent map already encompasses the 6980 * entire extent map we tried to add. 6981 */ 6982 free_extent_map(em); 6983 em = existing; 6984 err = 0; 6985 6986 } else if (start >= extent_map_end(existing) || 6987 start <= existing->start) { 6988 /* 6989 * The existing extent map is the one nearest to 6990 * the [start, start + len) range which overlaps 6991 */ 6992 err = merge_extent_mapping(em_tree, existing, 6993 em, start); 6994 free_extent_map(existing); 6995 if (err) { 6996 free_extent_map(em); 6997 em = NULL; 6998 } 6999 } else { 7000 free_extent_map(em); 7001 em = existing; 7002 err = 0; 7003 } 7004 } 7005 write_unlock(&em_tree->lock); 7006 out: 7007 7008 trace_btrfs_get_extent(root, inode, em); 7009 7010 btrfs_free_path(path); 7011 if (trans) { 7012 ret = btrfs_end_transaction(trans); 7013 if (!err) 7014 err = ret; 7015 } 7016 if (err) { 7017 free_extent_map(em); 7018 return ERR_PTR(err); 7019 } 7020 BUG_ON(!em); /* Error is always set */ 7021 return em; 7022 } 7023 7024 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode, 7025 struct page *page, 7026 size_t pg_offset, u64 start, u64 len, 7027 int create) 7028 { 7029 struct extent_map *em; 7030 struct extent_map *hole_em = NULL; 7031 u64 range_start = start; 7032 u64 end; 7033 u64 found; 7034 u64 found_end; 7035 int err = 0; 7036 7037 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 7038 if (IS_ERR(em)) 7039 return em; 7040 if (em) { 7041 /* 7042 * if our em maps to 7043 * - a hole or 7044 * - a pre-alloc extent, 7045 * there might actually be delalloc bytes behind it. 7046 */ 7047 if (em->block_start != EXTENT_MAP_HOLE && 7048 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7049 return em; 7050 else 7051 hole_em = em; 7052 } 7053 7054 /* check to see if we've wrapped (len == -1 or similar) */ 7055 end = start + len; 7056 if (end < start) 7057 end = (u64)-1; 7058 else 7059 end -= 1; 7060 7061 em = NULL; 7062 7063 /* ok, we didn't find anything, lets look for delalloc */ 7064 found = count_range_bits(&inode->io_tree, &range_start, 7065 end, len, EXTENT_DELALLOC, 1); 7066 found_end = range_start + found; 7067 if (found_end < range_start) 7068 found_end = (u64)-1; 7069 7070 /* 7071 * we didn't find anything useful, return 7072 * the original results from get_extent() 7073 */ 7074 if (range_start > end || found_end <= start) { 7075 em = hole_em; 7076 hole_em = NULL; 7077 goto out; 7078 } 7079 7080 /* adjust the range_start to make sure it doesn't 7081 * go backwards from the start they passed in 7082 */ 7083 range_start = max(start, range_start); 7084 found = found_end - range_start; 7085 7086 if (found > 0) { 7087 u64 hole_start = start; 7088 u64 hole_len = len; 7089 7090 em = alloc_extent_map(); 7091 if (!em) { 7092 err = -ENOMEM; 7093 goto out; 7094 } 7095 /* 7096 * when btrfs_get_extent can't find anything it 7097 * returns one huge hole 7098 * 7099 * make sure what it found really fits our range, and 7100 * adjust to make sure it is based on the start from 7101 * the caller 7102 */ 7103 if (hole_em) { 7104 u64 calc_end = extent_map_end(hole_em); 7105 7106 if (calc_end <= start || (hole_em->start > end)) { 7107 free_extent_map(hole_em); 7108 hole_em = NULL; 7109 } else { 7110 hole_start = max(hole_em->start, start); 7111 hole_len = calc_end - hole_start; 7112 } 7113 } 7114 em->bdev = NULL; 7115 if (hole_em && range_start > hole_start) { 7116 /* our hole starts before our delalloc, so we 7117 * have to return just the parts of the hole 7118 * that go until the delalloc starts 7119 */ 7120 em->len = min(hole_len, 7121 range_start - hole_start); 7122 em->start = hole_start; 7123 em->orig_start = hole_start; 7124 /* 7125 * don't adjust block start at all, 7126 * it is fixed at EXTENT_MAP_HOLE 7127 */ 7128 em->block_start = hole_em->block_start; 7129 em->block_len = hole_len; 7130 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 7131 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 7132 } else { 7133 em->start = range_start; 7134 em->len = found; 7135 em->orig_start = range_start; 7136 em->block_start = EXTENT_MAP_DELALLOC; 7137 em->block_len = found; 7138 } 7139 } else if (hole_em) { 7140 return hole_em; 7141 } 7142 out: 7143 7144 free_extent_map(hole_em); 7145 if (err) { 7146 free_extent_map(em); 7147 return ERR_PTR(err); 7148 } 7149 return em; 7150 } 7151 7152 static struct extent_map *btrfs_create_dio_extent(struct inode *inode, 7153 const u64 start, 7154 const u64 len, 7155 const u64 orig_start, 7156 const u64 block_start, 7157 const u64 block_len, 7158 const u64 orig_block_len, 7159 const u64 ram_bytes, 7160 const int type) 7161 { 7162 struct extent_map *em = NULL; 7163 int ret; 7164 7165 if (type != BTRFS_ORDERED_NOCOW) { 7166 em = create_io_em(inode, start, len, orig_start, 7167 block_start, block_len, orig_block_len, 7168 ram_bytes, 7169 BTRFS_COMPRESS_NONE, /* compress_type */ 7170 type); 7171 if (IS_ERR(em)) 7172 goto out; 7173 } 7174 ret = btrfs_add_ordered_extent_dio(inode, start, block_start, 7175 len, block_len, type); 7176 if (ret) { 7177 if (em) { 7178 free_extent_map(em); 7179 btrfs_drop_extent_cache(BTRFS_I(inode), start, 7180 start + len - 1, 0); 7181 } 7182 em = ERR_PTR(ret); 7183 } 7184 out: 7185 7186 return em; 7187 } 7188 7189 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 7190 u64 start, u64 len) 7191 { 7192 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 7193 struct btrfs_root *root = BTRFS_I(inode)->root; 7194 struct extent_map *em; 7195 struct btrfs_key ins; 7196 u64 alloc_hint; 7197 int ret; 7198 7199 alloc_hint = get_extent_allocation_hint(inode, start, len); 7200 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize, 7201 0, alloc_hint, &ins, 1, 1); 7202 if (ret) 7203 return ERR_PTR(ret); 7204 7205 em = btrfs_create_dio_extent(inode, start, ins.offset, start, 7206 ins.objectid, ins.offset, ins.offset, 7207 ins.offset, BTRFS_ORDERED_REGULAR); 7208 btrfs_dec_block_group_reservations(fs_info, ins.objectid); 7209 if (IS_ERR(em)) 7210 btrfs_free_reserved_extent(fs_info, ins.objectid, 7211 ins.offset, 1); 7212 7213 return em; 7214 } 7215 7216 /* 7217 * returns 1 when the nocow is safe, < 1 on error, 0 if the 7218 * block must be cow'd 7219 */ 7220 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, 7221 u64 *orig_start, u64 *orig_block_len, 7222 u64 *ram_bytes) 7223 { 7224 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 7225 struct btrfs_path *path; 7226 int ret; 7227 struct extent_buffer *leaf; 7228 struct btrfs_root *root = BTRFS_I(inode)->root; 7229 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7230 struct btrfs_file_extent_item *fi; 7231 struct btrfs_key key; 7232 u64 disk_bytenr; 7233 u64 backref_offset; 7234 u64 extent_end; 7235 u64 num_bytes; 7236 int slot; 7237 int found_type; 7238 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); 7239 7240 path = btrfs_alloc_path(); 7241 if (!path) 7242 return -ENOMEM; 7243 7244 ret = btrfs_lookup_file_extent(NULL, root, path, 7245 btrfs_ino(BTRFS_I(inode)), offset, 0); 7246 if (ret < 0) 7247 goto out; 7248 7249 slot = path->slots[0]; 7250 if (ret == 1) { 7251 if (slot == 0) { 7252 /* can't find the item, must cow */ 7253 ret = 0; 7254 goto out; 7255 } 7256 slot--; 7257 } 7258 ret = 0; 7259 leaf = path->nodes[0]; 7260 btrfs_item_key_to_cpu(leaf, &key, slot); 7261 if (key.objectid != btrfs_ino(BTRFS_I(inode)) || 7262 key.type != BTRFS_EXTENT_DATA_KEY) { 7263 /* not our file or wrong item type, must cow */ 7264 goto out; 7265 } 7266 7267 if (key.offset > offset) { 7268 /* Wrong offset, must cow */ 7269 goto out; 7270 } 7271 7272 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 7273 found_type = btrfs_file_extent_type(leaf, fi); 7274 if (found_type != BTRFS_FILE_EXTENT_REG && 7275 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 7276 /* not a regular extent, must cow */ 7277 goto out; 7278 } 7279 7280 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) 7281 goto out; 7282 7283 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 7284 if (extent_end <= offset) 7285 goto out; 7286 7287 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 7288 if (disk_bytenr == 0) 7289 goto out; 7290 7291 if (btrfs_file_extent_compression(leaf, fi) || 7292 btrfs_file_extent_encryption(leaf, fi) || 7293 btrfs_file_extent_other_encoding(leaf, fi)) 7294 goto out; 7295 7296 backref_offset = btrfs_file_extent_offset(leaf, fi); 7297 7298 if (orig_start) { 7299 *orig_start = key.offset - backref_offset; 7300 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 7301 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 7302 } 7303 7304 if (btrfs_extent_readonly(fs_info, disk_bytenr)) 7305 goto out; 7306 7307 num_bytes = min(offset + *len, extent_end) - offset; 7308 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { 7309 u64 range_end; 7310 7311 range_end = round_up(offset + num_bytes, 7312 root->fs_info->sectorsize) - 1; 7313 ret = test_range_bit(io_tree, offset, range_end, 7314 EXTENT_DELALLOC, 0, NULL); 7315 if (ret) { 7316 ret = -EAGAIN; 7317 goto out; 7318 } 7319 } 7320 7321 btrfs_release_path(path); 7322 7323 /* 7324 * look for other files referencing this extent, if we 7325 * find any we must cow 7326 */ 7327 7328 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)), 7329 key.offset - backref_offset, disk_bytenr); 7330 if (ret) { 7331 ret = 0; 7332 goto out; 7333 } 7334 7335 /* 7336 * adjust disk_bytenr and num_bytes to cover just the bytes 7337 * in this extent we are about to write. If there 7338 * are any csums in that range we have to cow in order 7339 * to keep the csums correct 7340 */ 7341 disk_bytenr += backref_offset; 7342 disk_bytenr += offset - key.offset; 7343 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes)) 7344 goto out; 7345 /* 7346 * all of the above have passed, it is safe to overwrite this extent 7347 * without cow 7348 */ 7349 *len = num_bytes; 7350 ret = 1; 7351 out: 7352 btrfs_free_path(path); 7353 return ret; 7354 } 7355 7356 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end) 7357 { 7358 struct radix_tree_root *root = &inode->i_mapping->page_tree; 7359 int found = false; 7360 void **pagep = NULL; 7361 struct page *page = NULL; 7362 int start_idx; 7363 int end_idx; 7364 7365 start_idx = start >> PAGE_SHIFT; 7366 7367 /* 7368 * end is the last byte in the last page. end == start is legal 7369 */ 7370 end_idx = end >> PAGE_SHIFT; 7371 7372 rcu_read_lock(); 7373 7374 /* Most of the code in this while loop is lifted from 7375 * find_get_page. It's been modified to begin searching from a 7376 * page and return just the first page found in that range. If the 7377 * found idx is less than or equal to the end idx then we know that 7378 * a page exists. If no pages are found or if those pages are 7379 * outside of the range then we're fine (yay!) */ 7380 while (page == NULL && 7381 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) { 7382 page = radix_tree_deref_slot(pagep); 7383 if (unlikely(!page)) 7384 break; 7385 7386 if (radix_tree_exception(page)) { 7387 if (radix_tree_deref_retry(page)) { 7388 page = NULL; 7389 continue; 7390 } 7391 /* 7392 * Otherwise, shmem/tmpfs must be storing a swap entry 7393 * here as an exceptional entry: so return it without 7394 * attempting to raise page count. 7395 */ 7396 page = NULL; 7397 break; /* TODO: Is this relevant for this use case? */ 7398 } 7399 7400 if (!page_cache_get_speculative(page)) { 7401 page = NULL; 7402 continue; 7403 } 7404 7405 /* 7406 * Has the page moved? 7407 * This is part of the lockless pagecache protocol. See 7408 * include/linux/pagemap.h for details. 7409 */ 7410 if (unlikely(page != *pagep)) { 7411 put_page(page); 7412 page = NULL; 7413 } 7414 } 7415 7416 if (page) { 7417 if (page->index <= end_idx) 7418 found = true; 7419 put_page(page); 7420 } 7421 7422 rcu_read_unlock(); 7423 return found; 7424 } 7425 7426 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 7427 struct extent_state **cached_state, int writing) 7428 { 7429 struct btrfs_ordered_extent *ordered; 7430 int ret = 0; 7431 7432 while (1) { 7433 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7434 cached_state); 7435 /* 7436 * We're concerned with the entire range that we're going to be 7437 * doing DIO to, so we need to make sure there's no ordered 7438 * extents in this range. 7439 */ 7440 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart, 7441 lockend - lockstart + 1); 7442 7443 /* 7444 * We need to make sure there are no buffered pages in this 7445 * range either, we could have raced between the invalidate in 7446 * generic_file_direct_write and locking the extent. The 7447 * invalidate needs to happen so that reads after a write do not 7448 * get stale data. 7449 */ 7450 if (!ordered && 7451 (!writing || 7452 !btrfs_page_exists_in_range(inode, lockstart, lockend))) 7453 break; 7454 7455 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7456 cached_state, GFP_NOFS); 7457 7458 if (ordered) { 7459 /* 7460 * If we are doing a DIO read and the ordered extent we 7461 * found is for a buffered write, we can not wait for it 7462 * to complete and retry, because if we do so we can 7463 * deadlock with concurrent buffered writes on page 7464 * locks. This happens only if our DIO read covers more 7465 * than one extent map, if at this point has already 7466 * created an ordered extent for a previous extent map 7467 * and locked its range in the inode's io tree, and a 7468 * concurrent write against that previous extent map's 7469 * range and this range started (we unlock the ranges 7470 * in the io tree only when the bios complete and 7471 * buffered writes always lock pages before attempting 7472 * to lock range in the io tree). 7473 */ 7474 if (writing || 7475 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) 7476 btrfs_start_ordered_extent(inode, ordered, 1); 7477 else 7478 ret = -ENOTBLK; 7479 btrfs_put_ordered_extent(ordered); 7480 } else { 7481 /* 7482 * We could trigger writeback for this range (and wait 7483 * for it to complete) and then invalidate the pages for 7484 * this range (through invalidate_inode_pages2_range()), 7485 * but that can lead us to a deadlock with a concurrent 7486 * call to readpages() (a buffered read or a defrag call 7487 * triggered a readahead) on a page lock due to an 7488 * ordered dio extent we created before but did not have 7489 * yet a corresponding bio submitted (whence it can not 7490 * complete), which makes readpages() wait for that 7491 * ordered extent to complete while holding a lock on 7492 * that page. 7493 */ 7494 ret = -ENOTBLK; 7495 } 7496 7497 if (ret) 7498 break; 7499 7500 cond_resched(); 7501 } 7502 7503 return ret; 7504 } 7505 7506 /* The callers of this must take lock_extent() */ 7507 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len, 7508 u64 orig_start, u64 block_start, 7509 u64 block_len, u64 orig_block_len, 7510 u64 ram_bytes, int compress_type, 7511 int type) 7512 { 7513 struct extent_map_tree *em_tree; 7514 struct extent_map *em; 7515 struct btrfs_root *root = BTRFS_I(inode)->root; 7516 int ret; 7517 7518 ASSERT(type == BTRFS_ORDERED_PREALLOC || 7519 type == BTRFS_ORDERED_COMPRESSED || 7520 type == BTRFS_ORDERED_NOCOW || 7521 type == BTRFS_ORDERED_REGULAR); 7522 7523 em_tree = &BTRFS_I(inode)->extent_tree; 7524 em = alloc_extent_map(); 7525 if (!em) 7526 return ERR_PTR(-ENOMEM); 7527 7528 em->start = start; 7529 em->orig_start = orig_start; 7530 em->len = len; 7531 em->block_len = block_len; 7532 em->block_start = block_start; 7533 em->bdev = root->fs_info->fs_devices->latest_bdev; 7534 em->orig_block_len = orig_block_len; 7535 em->ram_bytes = ram_bytes; 7536 em->generation = -1; 7537 set_bit(EXTENT_FLAG_PINNED, &em->flags); 7538 if (type == BTRFS_ORDERED_PREALLOC) { 7539 set_bit(EXTENT_FLAG_FILLING, &em->flags); 7540 } else if (type == BTRFS_ORDERED_COMPRESSED) { 7541 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 7542 em->compress_type = compress_type; 7543 } 7544 7545 do { 7546 btrfs_drop_extent_cache(BTRFS_I(inode), em->start, 7547 em->start + em->len - 1, 0); 7548 write_lock(&em_tree->lock); 7549 ret = add_extent_mapping(em_tree, em, 1); 7550 write_unlock(&em_tree->lock); 7551 /* 7552 * The caller has taken lock_extent(), who could race with us 7553 * to add em? 7554 */ 7555 } while (ret == -EEXIST); 7556 7557 if (ret) { 7558 free_extent_map(em); 7559 return ERR_PTR(ret); 7560 } 7561 7562 /* em got 2 refs now, callers needs to do free_extent_map once. */ 7563 return em; 7564 } 7565 7566 static void adjust_dio_outstanding_extents(struct inode *inode, 7567 struct btrfs_dio_data *dio_data, 7568 const u64 len) 7569 { 7570 unsigned num_extents = count_max_extents(len); 7571 7572 /* 7573 * If we have an outstanding_extents count still set then we're 7574 * within our reservation, otherwise we need to adjust our inode 7575 * counter appropriately. 7576 */ 7577 if (dio_data->outstanding_extents >= num_extents) { 7578 dio_data->outstanding_extents -= num_extents; 7579 } else { 7580 /* 7581 * If dio write length has been split due to no large enough 7582 * contiguous space, we need to compensate our inode counter 7583 * appropriately. 7584 */ 7585 u64 num_needed = num_extents - dio_data->outstanding_extents; 7586 7587 spin_lock(&BTRFS_I(inode)->lock); 7588 BTRFS_I(inode)->outstanding_extents += num_needed; 7589 spin_unlock(&BTRFS_I(inode)->lock); 7590 } 7591 } 7592 7593 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 7594 struct buffer_head *bh_result, int create) 7595 { 7596 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 7597 struct extent_map *em; 7598 struct extent_state *cached_state = NULL; 7599 struct btrfs_dio_data *dio_data = NULL; 7600 u64 start = iblock << inode->i_blkbits; 7601 u64 lockstart, lockend; 7602 u64 len = bh_result->b_size; 7603 int unlock_bits = EXTENT_LOCKED; 7604 int ret = 0; 7605 7606 if (create) 7607 unlock_bits |= EXTENT_DIRTY; 7608 else 7609 len = min_t(u64, len, fs_info->sectorsize); 7610 7611 lockstart = start; 7612 lockend = start + len - 1; 7613 7614 if (current->journal_info) { 7615 /* 7616 * Need to pull our outstanding extents and set journal_info to NULL so 7617 * that anything that needs to check if there's a transaction doesn't get 7618 * confused. 7619 */ 7620 dio_data = current->journal_info; 7621 current->journal_info = NULL; 7622 } 7623 7624 /* 7625 * If this errors out it's because we couldn't invalidate pagecache for 7626 * this range and we need to fallback to buffered. 7627 */ 7628 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, 7629 create)) { 7630 ret = -ENOTBLK; 7631 goto err; 7632 } 7633 7634 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0); 7635 if (IS_ERR(em)) { 7636 ret = PTR_ERR(em); 7637 goto unlock_err; 7638 } 7639 7640 /* 7641 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 7642 * io. INLINE is special, and we could probably kludge it in here, but 7643 * it's still buffered so for safety lets just fall back to the generic 7644 * buffered path. 7645 * 7646 * For COMPRESSED we _have_ to read the entire extent in so we can 7647 * decompress it, so there will be buffering required no matter what we 7648 * do, so go ahead and fallback to buffered. 7649 * 7650 * We return -ENOTBLK because that's what makes DIO go ahead and go back 7651 * to buffered IO. Don't blame me, this is the price we pay for using 7652 * the generic code. 7653 */ 7654 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 7655 em->block_start == EXTENT_MAP_INLINE) { 7656 free_extent_map(em); 7657 ret = -ENOTBLK; 7658 goto unlock_err; 7659 } 7660 7661 /* Just a good old fashioned hole, return */ 7662 if (!create && (em->block_start == EXTENT_MAP_HOLE || 7663 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 7664 free_extent_map(em); 7665 goto unlock_err; 7666 } 7667 7668 /* 7669 * We don't allocate a new extent in the following cases 7670 * 7671 * 1) The inode is marked as NODATACOW. In this case we'll just use the 7672 * existing extent. 7673 * 2) The extent is marked as PREALLOC. We're good to go here and can 7674 * just use the extent. 7675 * 7676 */ 7677 if (!create) { 7678 len = min(len, em->len - (start - em->start)); 7679 lockstart = start + len; 7680 goto unlock; 7681 } 7682 7683 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 7684 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 7685 em->block_start != EXTENT_MAP_HOLE)) { 7686 int type; 7687 u64 block_start, orig_start, orig_block_len, ram_bytes; 7688 7689 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7690 type = BTRFS_ORDERED_PREALLOC; 7691 else 7692 type = BTRFS_ORDERED_NOCOW; 7693 len = min(len, em->len - (start - em->start)); 7694 block_start = em->block_start + (start - em->start); 7695 7696 if (can_nocow_extent(inode, start, &len, &orig_start, 7697 &orig_block_len, &ram_bytes) == 1 && 7698 btrfs_inc_nocow_writers(fs_info, block_start)) { 7699 struct extent_map *em2; 7700 7701 em2 = btrfs_create_dio_extent(inode, start, len, 7702 orig_start, block_start, 7703 len, orig_block_len, 7704 ram_bytes, type); 7705 btrfs_dec_nocow_writers(fs_info, block_start); 7706 if (type == BTRFS_ORDERED_PREALLOC) { 7707 free_extent_map(em); 7708 em = em2; 7709 } 7710 if (em2 && IS_ERR(em2)) { 7711 ret = PTR_ERR(em2); 7712 goto unlock_err; 7713 } 7714 /* 7715 * For inode marked NODATACOW or extent marked PREALLOC, 7716 * use the existing or preallocated extent, so does not 7717 * need to adjust btrfs_space_info's bytes_may_use. 7718 */ 7719 btrfs_free_reserved_data_space_noquota(inode, 7720 start, len); 7721 goto unlock; 7722 } 7723 } 7724 7725 /* 7726 * this will cow the extent, reset the len in case we changed 7727 * it above 7728 */ 7729 len = bh_result->b_size; 7730 free_extent_map(em); 7731 em = btrfs_new_extent_direct(inode, start, len); 7732 if (IS_ERR(em)) { 7733 ret = PTR_ERR(em); 7734 goto unlock_err; 7735 } 7736 len = min(len, em->len - (start - em->start)); 7737 unlock: 7738 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 7739 inode->i_blkbits; 7740 bh_result->b_size = len; 7741 bh_result->b_bdev = em->bdev; 7742 set_buffer_mapped(bh_result); 7743 if (create) { 7744 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7745 set_buffer_new(bh_result); 7746 7747 /* 7748 * Need to update the i_size under the extent lock so buffered 7749 * readers will get the updated i_size when we unlock. 7750 */ 7751 if (!dio_data->overwrite && start + len > i_size_read(inode)) 7752 i_size_write(inode, start + len); 7753 7754 adjust_dio_outstanding_extents(inode, dio_data, len); 7755 WARN_ON(dio_data->reserve < len); 7756 dio_data->reserve -= len; 7757 dio_data->unsubmitted_oe_range_end = start + len; 7758 current->journal_info = dio_data; 7759 } 7760 7761 /* 7762 * In the case of write we need to clear and unlock the entire range, 7763 * in the case of read we need to unlock only the end area that we 7764 * aren't using if there is any left over space. 7765 */ 7766 if (lockstart < lockend) { 7767 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 7768 lockend, unlock_bits, 1, 0, 7769 &cached_state, GFP_NOFS); 7770 } else { 7771 free_extent_state(cached_state); 7772 } 7773 7774 free_extent_map(em); 7775 7776 return 0; 7777 7778 unlock_err: 7779 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7780 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 7781 err: 7782 if (dio_data) 7783 current->journal_info = dio_data; 7784 /* 7785 * Compensate the delalloc release we do in btrfs_direct_IO() when we 7786 * write less data then expected, so that we don't underflow our inode's 7787 * outstanding extents counter. 7788 */ 7789 if (create && dio_data) 7790 adjust_dio_outstanding_extents(inode, dio_data, len); 7791 7792 return ret; 7793 } 7794 7795 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio, 7796 int mirror_num) 7797 { 7798 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 7799 int ret; 7800 7801 BUG_ON(bio_op(bio) == REQ_OP_WRITE); 7802 7803 bio_get(bio); 7804 7805 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR); 7806 if (ret) 7807 goto err; 7808 7809 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0); 7810 err: 7811 bio_put(bio); 7812 return ret; 7813 } 7814 7815 static int btrfs_check_dio_repairable(struct inode *inode, 7816 struct bio *failed_bio, 7817 struct io_failure_record *failrec, 7818 int failed_mirror) 7819 { 7820 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 7821 int num_copies; 7822 7823 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len); 7824 if (num_copies == 1) { 7825 /* 7826 * we only have a single copy of the data, so don't bother with 7827 * all the retry and error correction code that follows. no 7828 * matter what the error is, it is very likely to persist. 7829 */ 7830 btrfs_debug(fs_info, 7831 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d", 7832 num_copies, failrec->this_mirror, failed_mirror); 7833 return 0; 7834 } 7835 7836 failrec->failed_mirror = failed_mirror; 7837 failrec->this_mirror++; 7838 if (failrec->this_mirror == failed_mirror) 7839 failrec->this_mirror++; 7840 7841 if (failrec->this_mirror > num_copies) { 7842 btrfs_debug(fs_info, 7843 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d", 7844 num_copies, failrec->this_mirror, failed_mirror); 7845 return 0; 7846 } 7847 7848 return 1; 7849 } 7850 7851 static int dio_read_error(struct inode *inode, struct bio *failed_bio, 7852 struct page *page, unsigned int pgoff, 7853 u64 start, u64 end, int failed_mirror, 7854 bio_end_io_t *repair_endio, void *repair_arg) 7855 { 7856 struct io_failure_record *failrec; 7857 struct bio *bio; 7858 int isector; 7859 int read_mode = 0; 7860 int ret; 7861 7862 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE); 7863 7864 ret = btrfs_get_io_failure_record(inode, start, end, &failrec); 7865 if (ret) 7866 return ret; 7867 7868 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec, 7869 failed_mirror); 7870 if (!ret) { 7871 free_io_failure(BTRFS_I(inode), failrec); 7872 return -EIO; 7873 } 7874 7875 if ((failed_bio->bi_vcnt > 1) 7876 || (failed_bio->bi_io_vec->bv_len 7877 > btrfs_inode_sectorsize(inode))) 7878 read_mode |= REQ_FAILFAST_DEV; 7879 7880 isector = start - btrfs_io_bio(failed_bio)->logical; 7881 isector >>= inode->i_sb->s_blocksize_bits; 7882 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, 7883 pgoff, isector, repair_endio, repair_arg); 7884 if (!bio) { 7885 free_io_failure(BTRFS_I(inode), failrec); 7886 return -EIO; 7887 } 7888 bio_set_op_attrs(bio, REQ_OP_READ, read_mode); 7889 7890 btrfs_debug(BTRFS_I(inode)->root->fs_info, 7891 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n", 7892 read_mode, failrec->this_mirror, failrec->in_validation); 7893 7894 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror); 7895 if (ret) { 7896 free_io_failure(BTRFS_I(inode), failrec); 7897 bio_put(bio); 7898 } 7899 7900 return ret; 7901 } 7902 7903 struct btrfs_retry_complete { 7904 struct completion done; 7905 struct inode *inode; 7906 u64 start; 7907 int uptodate; 7908 }; 7909 7910 static void btrfs_retry_endio_nocsum(struct bio *bio) 7911 { 7912 struct btrfs_retry_complete *done = bio->bi_private; 7913 struct bio_vec *bvec; 7914 int i; 7915 7916 if (bio->bi_error) 7917 goto end; 7918 7919 ASSERT(bio->bi_vcnt == 1); 7920 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode)); 7921 7922 done->uptodate = 1; 7923 bio_for_each_segment_all(bvec, bio, i) 7924 clean_io_failure(BTRFS_I(done->inode), done->start, 7925 bvec->bv_page, 0); 7926 end: 7927 complete(&done->done); 7928 bio_put(bio); 7929 } 7930 7931 static int __btrfs_correct_data_nocsum(struct inode *inode, 7932 struct btrfs_io_bio *io_bio) 7933 { 7934 struct btrfs_fs_info *fs_info; 7935 struct bio_vec *bvec; 7936 struct btrfs_retry_complete done; 7937 u64 start; 7938 unsigned int pgoff; 7939 u32 sectorsize; 7940 int nr_sectors; 7941 int i; 7942 int ret; 7943 7944 fs_info = BTRFS_I(inode)->root->fs_info; 7945 sectorsize = fs_info->sectorsize; 7946 7947 start = io_bio->logical; 7948 done.inode = inode; 7949 7950 bio_for_each_segment_all(bvec, &io_bio->bio, i) { 7951 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len); 7952 pgoff = bvec->bv_offset; 7953 7954 next_block_or_try_again: 7955 done.uptodate = 0; 7956 done.start = start; 7957 init_completion(&done.done); 7958 7959 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, 7960 pgoff, start, start + sectorsize - 1, 7961 io_bio->mirror_num, 7962 btrfs_retry_endio_nocsum, &done); 7963 if (ret) 7964 return ret; 7965 7966 wait_for_completion(&done.done); 7967 7968 if (!done.uptodate) { 7969 /* We might have another mirror, so try again */ 7970 goto next_block_or_try_again; 7971 } 7972 7973 start += sectorsize; 7974 7975 nr_sectors--; 7976 if (nr_sectors) { 7977 pgoff += sectorsize; 7978 ASSERT(pgoff < PAGE_SIZE); 7979 goto next_block_or_try_again; 7980 } 7981 } 7982 7983 return 0; 7984 } 7985 7986 static void btrfs_retry_endio(struct bio *bio) 7987 { 7988 struct btrfs_retry_complete *done = bio->bi_private; 7989 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 7990 struct bio_vec *bvec; 7991 int uptodate; 7992 int ret; 7993 int i; 7994 7995 if (bio->bi_error) 7996 goto end; 7997 7998 uptodate = 1; 7999 8000 ASSERT(bio->bi_vcnt == 1); 8001 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode)); 8002 8003 bio_for_each_segment_all(bvec, bio, i) { 8004 ret = __readpage_endio_check(done->inode, io_bio, i, 8005 bvec->bv_page, bvec->bv_offset, 8006 done->start, bvec->bv_len); 8007 if (!ret) 8008 clean_io_failure(BTRFS_I(done->inode), done->start, 8009 bvec->bv_page, bvec->bv_offset); 8010 else 8011 uptodate = 0; 8012 } 8013 8014 done->uptodate = uptodate; 8015 end: 8016 complete(&done->done); 8017 bio_put(bio); 8018 } 8019 8020 static int __btrfs_subio_endio_read(struct inode *inode, 8021 struct btrfs_io_bio *io_bio, int err) 8022 { 8023 struct btrfs_fs_info *fs_info; 8024 struct bio_vec *bvec; 8025 struct btrfs_retry_complete done; 8026 u64 start; 8027 u64 offset = 0; 8028 u32 sectorsize; 8029 int nr_sectors; 8030 unsigned int pgoff; 8031 int csum_pos; 8032 int i; 8033 int ret; 8034 8035 fs_info = BTRFS_I(inode)->root->fs_info; 8036 sectorsize = fs_info->sectorsize; 8037 8038 err = 0; 8039 start = io_bio->logical; 8040 done.inode = inode; 8041 8042 bio_for_each_segment_all(bvec, &io_bio->bio, i) { 8043 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len); 8044 8045 pgoff = bvec->bv_offset; 8046 next_block: 8047 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset); 8048 ret = __readpage_endio_check(inode, io_bio, csum_pos, 8049 bvec->bv_page, pgoff, start, 8050 sectorsize); 8051 if (likely(!ret)) 8052 goto next; 8053 try_again: 8054 done.uptodate = 0; 8055 done.start = start; 8056 init_completion(&done.done); 8057 8058 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, 8059 pgoff, start, start + sectorsize - 1, 8060 io_bio->mirror_num, 8061 btrfs_retry_endio, &done); 8062 if (ret) { 8063 err = ret; 8064 goto next; 8065 } 8066 8067 wait_for_completion(&done.done); 8068 8069 if (!done.uptodate) { 8070 /* We might have another mirror, so try again */ 8071 goto try_again; 8072 } 8073 next: 8074 offset += sectorsize; 8075 start += sectorsize; 8076 8077 ASSERT(nr_sectors); 8078 8079 nr_sectors--; 8080 if (nr_sectors) { 8081 pgoff += sectorsize; 8082 ASSERT(pgoff < PAGE_SIZE); 8083 goto next_block; 8084 } 8085 } 8086 8087 return err; 8088 } 8089 8090 static int btrfs_subio_endio_read(struct inode *inode, 8091 struct btrfs_io_bio *io_bio, int err) 8092 { 8093 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 8094 8095 if (skip_csum) { 8096 if (unlikely(err)) 8097 return __btrfs_correct_data_nocsum(inode, io_bio); 8098 else 8099 return 0; 8100 } else { 8101 return __btrfs_subio_endio_read(inode, io_bio, err); 8102 } 8103 } 8104 8105 static void btrfs_endio_direct_read(struct bio *bio) 8106 { 8107 struct btrfs_dio_private *dip = bio->bi_private; 8108 struct inode *inode = dip->inode; 8109 struct bio *dio_bio; 8110 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 8111 int err = bio->bi_error; 8112 8113 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) 8114 err = btrfs_subio_endio_read(inode, io_bio, err); 8115 8116 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 8117 dip->logical_offset + dip->bytes - 1); 8118 dio_bio = dip->dio_bio; 8119 8120 kfree(dip); 8121 8122 dio_bio->bi_error = bio->bi_error; 8123 dio_end_io(dio_bio, bio->bi_error); 8124 8125 if (io_bio->end_io) 8126 io_bio->end_io(io_bio, err); 8127 bio_put(bio); 8128 } 8129 8130 static void btrfs_endio_direct_write_update_ordered(struct inode *inode, 8131 const u64 offset, 8132 const u64 bytes, 8133 const int uptodate) 8134 { 8135 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 8136 struct btrfs_ordered_extent *ordered = NULL; 8137 u64 ordered_offset = offset; 8138 u64 ordered_bytes = bytes; 8139 int ret; 8140 8141 again: 8142 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 8143 &ordered_offset, 8144 ordered_bytes, 8145 uptodate); 8146 if (!ret) 8147 goto out_test; 8148 8149 btrfs_init_work(&ordered->work, btrfs_endio_write_helper, 8150 finish_ordered_fn, NULL, NULL); 8151 btrfs_queue_work(fs_info->endio_write_workers, &ordered->work); 8152 out_test: 8153 /* 8154 * our bio might span multiple ordered extents. If we haven't 8155 * completed the accounting for the whole dio, go back and try again 8156 */ 8157 if (ordered_offset < offset + bytes) { 8158 ordered_bytes = offset + bytes - ordered_offset; 8159 ordered = NULL; 8160 goto again; 8161 } 8162 } 8163 8164 static void btrfs_endio_direct_write(struct bio *bio) 8165 { 8166 struct btrfs_dio_private *dip = bio->bi_private; 8167 struct bio *dio_bio = dip->dio_bio; 8168 8169 btrfs_endio_direct_write_update_ordered(dip->inode, 8170 dip->logical_offset, 8171 dip->bytes, 8172 !bio->bi_error); 8173 8174 kfree(dip); 8175 8176 dio_bio->bi_error = bio->bi_error; 8177 dio_end_io(dio_bio, bio->bi_error); 8178 bio_put(bio); 8179 } 8180 8181 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, 8182 struct bio *bio, int mirror_num, 8183 unsigned long bio_flags, u64 offset) 8184 { 8185 int ret; 8186 ret = btrfs_csum_one_bio(inode, bio, offset, 1); 8187 BUG_ON(ret); /* -ENOMEM */ 8188 return 0; 8189 } 8190 8191 static void btrfs_end_dio_bio(struct bio *bio) 8192 { 8193 struct btrfs_dio_private *dip = bio->bi_private; 8194 int err = bio->bi_error; 8195 8196 if (err) 8197 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info, 8198 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d", 8199 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio), 8200 bio->bi_opf, 8201 (unsigned long long)bio->bi_iter.bi_sector, 8202 bio->bi_iter.bi_size, err); 8203 8204 if (dip->subio_endio) 8205 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err); 8206 8207 if (err) { 8208 dip->errors = 1; 8209 8210 /* 8211 * before atomic variable goto zero, we must make sure 8212 * dip->errors is perceived to be set. 8213 */ 8214 smp_mb__before_atomic(); 8215 } 8216 8217 /* if there are more bios still pending for this dio, just exit */ 8218 if (!atomic_dec_and_test(&dip->pending_bios)) 8219 goto out; 8220 8221 if (dip->errors) { 8222 bio_io_error(dip->orig_bio); 8223 } else { 8224 dip->dio_bio->bi_error = 0; 8225 bio_endio(dip->orig_bio); 8226 } 8227 out: 8228 bio_put(bio); 8229 } 8230 8231 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 8232 u64 first_sector, gfp_t gfp_flags) 8233 { 8234 struct bio *bio; 8235 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags); 8236 if (bio) 8237 bio_associate_current(bio); 8238 return bio; 8239 } 8240 8241 static inline int btrfs_lookup_and_bind_dio_csum(struct inode *inode, 8242 struct btrfs_dio_private *dip, 8243 struct bio *bio, 8244 u64 file_offset) 8245 { 8246 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 8247 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio); 8248 int ret; 8249 8250 /* 8251 * We load all the csum data we need when we submit 8252 * the first bio to reduce the csum tree search and 8253 * contention. 8254 */ 8255 if (dip->logical_offset == file_offset) { 8256 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio, 8257 file_offset); 8258 if (ret) 8259 return ret; 8260 } 8261 8262 if (bio == dip->orig_bio) 8263 return 0; 8264 8265 file_offset -= dip->logical_offset; 8266 file_offset >>= inode->i_sb->s_blocksize_bits; 8267 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset); 8268 8269 return 0; 8270 } 8271 8272 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 8273 u64 file_offset, int skip_sum, 8274 int async_submit) 8275 { 8276 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 8277 struct btrfs_dio_private *dip = bio->bi_private; 8278 bool write = bio_op(bio) == REQ_OP_WRITE; 8279 int ret; 8280 8281 if (async_submit) 8282 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 8283 8284 bio_get(bio); 8285 8286 if (!write) { 8287 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); 8288 if (ret) 8289 goto err; 8290 } 8291 8292 if (skip_sum) 8293 goto map; 8294 8295 if (write && async_submit) { 8296 ret = btrfs_wq_submit_bio(fs_info, inode, bio, 0, 0, 8297 file_offset, 8298 __btrfs_submit_bio_start_direct_io, 8299 __btrfs_submit_bio_done); 8300 goto err; 8301 } else if (write) { 8302 /* 8303 * If we aren't doing async submit, calculate the csum of the 8304 * bio now. 8305 */ 8306 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1); 8307 if (ret) 8308 goto err; 8309 } else { 8310 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio, 8311 file_offset); 8312 if (ret) 8313 goto err; 8314 } 8315 map: 8316 ret = btrfs_map_bio(fs_info, bio, 0, async_submit); 8317 err: 8318 bio_put(bio); 8319 return ret; 8320 } 8321 8322 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip, 8323 int skip_sum) 8324 { 8325 struct inode *inode = dip->inode; 8326 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 8327 struct btrfs_root *root = BTRFS_I(inode)->root; 8328 struct bio *bio; 8329 struct bio *orig_bio = dip->orig_bio; 8330 struct bio_vec *bvec; 8331 u64 start_sector = orig_bio->bi_iter.bi_sector; 8332 u64 file_offset = dip->logical_offset; 8333 u64 submit_len = 0; 8334 u64 map_length; 8335 u32 blocksize = fs_info->sectorsize; 8336 int async_submit = 0; 8337 int nr_sectors; 8338 int ret; 8339 int i, j; 8340 8341 map_length = orig_bio->bi_iter.bi_size; 8342 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9, 8343 &map_length, NULL, 0); 8344 if (ret) 8345 return -EIO; 8346 8347 if (map_length >= orig_bio->bi_iter.bi_size) { 8348 bio = orig_bio; 8349 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED; 8350 goto submit; 8351 } 8352 8353 /* async crcs make it difficult to collect full stripe writes. */ 8354 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK) 8355 async_submit = 0; 8356 else 8357 async_submit = 1; 8358 8359 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 8360 if (!bio) 8361 return -ENOMEM; 8362 8363 bio->bi_opf = orig_bio->bi_opf; 8364 bio->bi_private = dip; 8365 bio->bi_end_io = btrfs_end_dio_bio; 8366 btrfs_io_bio(bio)->logical = file_offset; 8367 atomic_inc(&dip->pending_bios); 8368 8369 bio_for_each_segment_all(bvec, orig_bio, j) { 8370 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len); 8371 i = 0; 8372 next_block: 8373 if (unlikely(map_length < submit_len + blocksize || 8374 bio_add_page(bio, bvec->bv_page, blocksize, 8375 bvec->bv_offset + (i * blocksize)) < blocksize)) { 8376 /* 8377 * inc the count before we submit the bio so 8378 * we know the end IO handler won't happen before 8379 * we inc the count. Otherwise, the dip might get freed 8380 * before we're done setting it up 8381 */ 8382 atomic_inc(&dip->pending_bios); 8383 ret = __btrfs_submit_dio_bio(bio, inode, 8384 file_offset, skip_sum, 8385 async_submit); 8386 if (ret) { 8387 bio_put(bio); 8388 atomic_dec(&dip->pending_bios); 8389 goto out_err; 8390 } 8391 8392 start_sector += submit_len >> 9; 8393 file_offset += submit_len; 8394 8395 submit_len = 0; 8396 8397 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 8398 start_sector, GFP_NOFS); 8399 if (!bio) 8400 goto out_err; 8401 bio->bi_opf = orig_bio->bi_opf; 8402 bio->bi_private = dip; 8403 bio->bi_end_io = btrfs_end_dio_bio; 8404 btrfs_io_bio(bio)->logical = file_offset; 8405 8406 map_length = orig_bio->bi_iter.bi_size; 8407 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), 8408 start_sector << 9, 8409 &map_length, NULL, 0); 8410 if (ret) { 8411 bio_put(bio); 8412 goto out_err; 8413 } 8414 8415 goto next_block; 8416 } else { 8417 submit_len += blocksize; 8418 if (--nr_sectors) { 8419 i++; 8420 goto next_block; 8421 } 8422 } 8423 } 8424 8425 submit: 8426 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum, 8427 async_submit); 8428 if (!ret) 8429 return 0; 8430 8431 bio_put(bio); 8432 out_err: 8433 dip->errors = 1; 8434 /* 8435 * before atomic variable goto zero, we must 8436 * make sure dip->errors is perceived to be set. 8437 */ 8438 smp_mb__before_atomic(); 8439 if (atomic_dec_and_test(&dip->pending_bios)) 8440 bio_io_error(dip->orig_bio); 8441 8442 /* bio_end_io() will handle error, so we needn't return it */ 8443 return 0; 8444 } 8445 8446 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, 8447 loff_t file_offset) 8448 { 8449 struct btrfs_dio_private *dip = NULL; 8450 struct bio *io_bio = NULL; 8451 struct btrfs_io_bio *btrfs_bio; 8452 int skip_sum; 8453 bool write = (bio_op(dio_bio) == REQ_OP_WRITE); 8454 int ret = 0; 8455 8456 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 8457 8458 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); 8459 if (!io_bio) { 8460 ret = -ENOMEM; 8461 goto free_ordered; 8462 } 8463 8464 dip = kzalloc(sizeof(*dip), GFP_NOFS); 8465 if (!dip) { 8466 ret = -ENOMEM; 8467 goto free_ordered; 8468 } 8469 8470 dip->private = dio_bio->bi_private; 8471 dip->inode = inode; 8472 dip->logical_offset = file_offset; 8473 dip->bytes = dio_bio->bi_iter.bi_size; 8474 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; 8475 io_bio->bi_private = dip; 8476 dip->orig_bio = io_bio; 8477 dip->dio_bio = dio_bio; 8478 atomic_set(&dip->pending_bios, 0); 8479 btrfs_bio = btrfs_io_bio(io_bio); 8480 btrfs_bio->logical = file_offset; 8481 8482 if (write) { 8483 io_bio->bi_end_io = btrfs_endio_direct_write; 8484 } else { 8485 io_bio->bi_end_io = btrfs_endio_direct_read; 8486 dip->subio_endio = btrfs_subio_endio_read; 8487 } 8488 8489 /* 8490 * Reset the range for unsubmitted ordered extents (to a 0 length range) 8491 * even if we fail to submit a bio, because in such case we do the 8492 * corresponding error handling below and it must not be done a second 8493 * time by btrfs_direct_IO(). 8494 */ 8495 if (write) { 8496 struct btrfs_dio_data *dio_data = current->journal_info; 8497 8498 dio_data->unsubmitted_oe_range_end = dip->logical_offset + 8499 dip->bytes; 8500 dio_data->unsubmitted_oe_range_start = 8501 dio_data->unsubmitted_oe_range_end; 8502 } 8503 8504 ret = btrfs_submit_direct_hook(dip, skip_sum); 8505 if (!ret) 8506 return; 8507 8508 if (btrfs_bio->end_io) 8509 btrfs_bio->end_io(btrfs_bio, ret); 8510 8511 free_ordered: 8512 /* 8513 * If we arrived here it means either we failed to submit the dip 8514 * or we either failed to clone the dio_bio or failed to allocate the 8515 * dip. If we cloned the dio_bio and allocated the dip, we can just 8516 * call bio_endio against our io_bio so that we get proper resource 8517 * cleanup if we fail to submit the dip, otherwise, we must do the 8518 * same as btrfs_endio_direct_[write|read] because we can't call these 8519 * callbacks - they require an allocated dip and a clone of dio_bio. 8520 */ 8521 if (io_bio && dip) { 8522 io_bio->bi_error = -EIO; 8523 bio_endio(io_bio); 8524 /* 8525 * The end io callbacks free our dip, do the final put on io_bio 8526 * and all the cleanup and final put for dio_bio (through 8527 * dio_end_io()). 8528 */ 8529 dip = NULL; 8530 io_bio = NULL; 8531 } else { 8532 if (write) 8533 btrfs_endio_direct_write_update_ordered(inode, 8534 file_offset, 8535 dio_bio->bi_iter.bi_size, 8536 0); 8537 else 8538 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset, 8539 file_offset + dio_bio->bi_iter.bi_size - 1); 8540 8541 dio_bio->bi_error = -EIO; 8542 /* 8543 * Releases and cleans up our dio_bio, no need to bio_put() 8544 * nor bio_endio()/bio_io_error() against dio_bio. 8545 */ 8546 dio_end_io(dio_bio, ret); 8547 } 8548 if (io_bio) 8549 bio_put(io_bio); 8550 kfree(dip); 8551 } 8552 8553 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, 8554 struct kiocb *iocb, 8555 const struct iov_iter *iter, loff_t offset) 8556 { 8557 int seg; 8558 int i; 8559 unsigned int blocksize_mask = fs_info->sectorsize - 1; 8560 ssize_t retval = -EINVAL; 8561 8562 if (offset & blocksize_mask) 8563 goto out; 8564 8565 if (iov_iter_alignment(iter) & blocksize_mask) 8566 goto out; 8567 8568 /* If this is a write we don't need to check anymore */ 8569 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter)) 8570 return 0; 8571 /* 8572 * Check to make sure we don't have duplicate iov_base's in this 8573 * iovec, if so return EINVAL, otherwise we'll get csum errors 8574 * when reading back. 8575 */ 8576 for (seg = 0; seg < iter->nr_segs; seg++) { 8577 for (i = seg + 1; i < iter->nr_segs; i++) { 8578 if (iter->iov[seg].iov_base == iter->iov[i].iov_base) 8579 goto out; 8580 } 8581 } 8582 retval = 0; 8583 out: 8584 return retval; 8585 } 8586 8587 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 8588 { 8589 struct file *file = iocb->ki_filp; 8590 struct inode *inode = file->f_mapping->host; 8591 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 8592 struct btrfs_dio_data dio_data = { 0 }; 8593 loff_t offset = iocb->ki_pos; 8594 size_t count = 0; 8595 int flags = 0; 8596 bool wakeup = true; 8597 bool relock = false; 8598 ssize_t ret; 8599 8600 if (check_direct_IO(fs_info, iocb, iter, offset)) 8601 return 0; 8602 8603 inode_dio_begin(inode); 8604 smp_mb__after_atomic(); 8605 8606 /* 8607 * The generic stuff only does filemap_write_and_wait_range, which 8608 * isn't enough if we've written compressed pages to this area, so 8609 * we need to flush the dirty pages again to make absolutely sure 8610 * that any outstanding dirty pages are on disk. 8611 */ 8612 count = iov_iter_count(iter); 8613 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 8614 &BTRFS_I(inode)->runtime_flags)) 8615 filemap_fdatawrite_range(inode->i_mapping, offset, 8616 offset + count - 1); 8617 8618 if (iov_iter_rw(iter) == WRITE) { 8619 /* 8620 * If the write DIO is beyond the EOF, we need update 8621 * the isize, but it is protected by i_mutex. So we can 8622 * not unlock the i_mutex at this case. 8623 */ 8624 if (offset + count <= inode->i_size) { 8625 dio_data.overwrite = 1; 8626 inode_unlock(inode); 8627 relock = true; 8628 } 8629 ret = btrfs_delalloc_reserve_space(inode, offset, count); 8630 if (ret) 8631 goto out; 8632 dio_data.outstanding_extents = count_max_extents(count); 8633 8634 /* 8635 * We need to know how many extents we reserved so that we can 8636 * do the accounting properly if we go over the number we 8637 * originally calculated. Abuse current->journal_info for this. 8638 */ 8639 dio_data.reserve = round_up(count, 8640 fs_info->sectorsize); 8641 dio_data.unsubmitted_oe_range_start = (u64)offset; 8642 dio_data.unsubmitted_oe_range_end = (u64)offset; 8643 current->journal_info = &dio_data; 8644 down_read(&BTRFS_I(inode)->dio_sem); 8645 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 8646 &BTRFS_I(inode)->runtime_flags)) { 8647 inode_dio_end(inode); 8648 flags = DIO_LOCKING | DIO_SKIP_HOLES; 8649 wakeup = false; 8650 } 8651 8652 ret = __blockdev_direct_IO(iocb, inode, 8653 fs_info->fs_devices->latest_bdev, 8654 iter, btrfs_get_blocks_direct, NULL, 8655 btrfs_submit_direct, flags); 8656 if (iov_iter_rw(iter) == WRITE) { 8657 up_read(&BTRFS_I(inode)->dio_sem); 8658 current->journal_info = NULL; 8659 if (ret < 0 && ret != -EIOCBQUEUED) { 8660 if (dio_data.reserve) 8661 btrfs_delalloc_release_space(inode, offset, 8662 dio_data.reserve); 8663 /* 8664 * On error we might have left some ordered extents 8665 * without submitting corresponding bios for them, so 8666 * cleanup them up to avoid other tasks getting them 8667 * and waiting for them to complete forever. 8668 */ 8669 if (dio_data.unsubmitted_oe_range_start < 8670 dio_data.unsubmitted_oe_range_end) 8671 btrfs_endio_direct_write_update_ordered(inode, 8672 dio_data.unsubmitted_oe_range_start, 8673 dio_data.unsubmitted_oe_range_end - 8674 dio_data.unsubmitted_oe_range_start, 8675 0); 8676 } else if (ret >= 0 && (size_t)ret < count) 8677 btrfs_delalloc_release_space(inode, offset, 8678 count - (size_t)ret); 8679 } 8680 out: 8681 if (wakeup) 8682 inode_dio_end(inode); 8683 if (relock) 8684 inode_lock(inode); 8685 8686 return ret; 8687 } 8688 8689 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 8690 8691 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 8692 __u64 start, __u64 len) 8693 { 8694 int ret; 8695 8696 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 8697 if (ret) 8698 return ret; 8699 8700 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 8701 } 8702 8703 int btrfs_readpage(struct file *file, struct page *page) 8704 { 8705 struct extent_io_tree *tree; 8706 tree = &BTRFS_I(page->mapping->host)->io_tree; 8707 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 8708 } 8709 8710 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 8711 { 8712 struct extent_io_tree *tree; 8713 struct inode *inode = page->mapping->host; 8714 int ret; 8715 8716 if (current->flags & PF_MEMALLOC) { 8717 redirty_page_for_writepage(wbc, page); 8718 unlock_page(page); 8719 return 0; 8720 } 8721 8722 /* 8723 * If we are under memory pressure we will call this directly from the 8724 * VM, we need to make sure we have the inode referenced for the ordered 8725 * extent. If not just return like we didn't do anything. 8726 */ 8727 if (!igrab(inode)) { 8728 redirty_page_for_writepage(wbc, page); 8729 return AOP_WRITEPAGE_ACTIVATE; 8730 } 8731 tree = &BTRFS_I(page->mapping->host)->io_tree; 8732 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc); 8733 btrfs_add_delayed_iput(inode); 8734 return ret; 8735 } 8736 8737 static int btrfs_writepages(struct address_space *mapping, 8738 struct writeback_control *wbc) 8739 { 8740 struct extent_io_tree *tree; 8741 8742 tree = &BTRFS_I(mapping->host)->io_tree; 8743 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 8744 } 8745 8746 static int 8747 btrfs_readpages(struct file *file, struct address_space *mapping, 8748 struct list_head *pages, unsigned nr_pages) 8749 { 8750 struct extent_io_tree *tree; 8751 tree = &BTRFS_I(mapping->host)->io_tree; 8752 return extent_readpages(tree, mapping, pages, nr_pages, 8753 btrfs_get_extent); 8754 } 8755 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 8756 { 8757 struct extent_io_tree *tree; 8758 struct extent_map_tree *map; 8759 int ret; 8760 8761 tree = &BTRFS_I(page->mapping->host)->io_tree; 8762 map = &BTRFS_I(page->mapping->host)->extent_tree; 8763 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 8764 if (ret == 1) { 8765 ClearPagePrivate(page); 8766 set_page_private(page, 0); 8767 put_page(page); 8768 } 8769 return ret; 8770 } 8771 8772 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 8773 { 8774 if (PageWriteback(page) || PageDirty(page)) 8775 return 0; 8776 return __btrfs_releasepage(page, gfp_flags); 8777 } 8778 8779 static void btrfs_invalidatepage(struct page *page, unsigned int offset, 8780 unsigned int length) 8781 { 8782 struct inode *inode = page->mapping->host; 8783 struct extent_io_tree *tree; 8784 struct btrfs_ordered_extent *ordered; 8785 struct extent_state *cached_state = NULL; 8786 u64 page_start = page_offset(page); 8787 u64 page_end = page_start + PAGE_SIZE - 1; 8788 u64 start; 8789 u64 end; 8790 int inode_evicting = inode->i_state & I_FREEING; 8791 8792 /* 8793 * we have the page locked, so new writeback can't start, 8794 * and the dirty bit won't be cleared while we are here. 8795 * 8796 * Wait for IO on this page so that we can safely clear 8797 * the PagePrivate2 bit and do ordered accounting 8798 */ 8799 wait_on_page_writeback(page); 8800 8801 tree = &BTRFS_I(inode)->io_tree; 8802 if (offset) { 8803 btrfs_releasepage(page, GFP_NOFS); 8804 return; 8805 } 8806 8807 if (!inode_evicting) 8808 lock_extent_bits(tree, page_start, page_end, &cached_state); 8809 again: 8810 start = page_start; 8811 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start, 8812 page_end - start + 1); 8813 if (ordered) { 8814 end = min(page_end, ordered->file_offset + ordered->len - 1); 8815 /* 8816 * IO on this page will never be started, so we need 8817 * to account for any ordered extents now 8818 */ 8819 if (!inode_evicting) 8820 clear_extent_bit(tree, start, end, 8821 EXTENT_DIRTY | EXTENT_DELALLOC | 8822 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 8823 EXTENT_DEFRAG, 1, 0, &cached_state, 8824 GFP_NOFS); 8825 /* 8826 * whoever cleared the private bit is responsible 8827 * for the finish_ordered_io 8828 */ 8829 if (TestClearPagePrivate2(page)) { 8830 struct btrfs_ordered_inode_tree *tree; 8831 u64 new_len; 8832 8833 tree = &BTRFS_I(inode)->ordered_tree; 8834 8835 spin_lock_irq(&tree->lock); 8836 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); 8837 new_len = start - ordered->file_offset; 8838 if (new_len < ordered->truncated_len) 8839 ordered->truncated_len = new_len; 8840 spin_unlock_irq(&tree->lock); 8841 8842 if (btrfs_dec_test_ordered_pending(inode, &ordered, 8843 start, 8844 end - start + 1, 1)) 8845 btrfs_finish_ordered_io(ordered); 8846 } 8847 btrfs_put_ordered_extent(ordered); 8848 if (!inode_evicting) { 8849 cached_state = NULL; 8850 lock_extent_bits(tree, start, end, 8851 &cached_state); 8852 } 8853 8854 start = end + 1; 8855 if (start < page_end) 8856 goto again; 8857 } 8858 8859 /* 8860 * Qgroup reserved space handler 8861 * Page here will be either 8862 * 1) Already written to disk 8863 * In this case, its reserved space is released from data rsv map 8864 * and will be freed by delayed_ref handler finally. 8865 * So even we call qgroup_free_data(), it won't decrease reserved 8866 * space. 8867 * 2) Not written to disk 8868 * This means the reserved space should be freed here. However, 8869 * if a truncate invalidates the page (by clearing PageDirty) 8870 * and the page is accounted for while allocating extent 8871 * in btrfs_check_data_free_space() we let delayed_ref to 8872 * free the entire extent. 8873 */ 8874 if (PageDirty(page)) 8875 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE); 8876 if (!inode_evicting) { 8877 clear_extent_bit(tree, page_start, page_end, 8878 EXTENT_LOCKED | EXTENT_DIRTY | 8879 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 8880 EXTENT_DEFRAG, 1, 1, 8881 &cached_state, GFP_NOFS); 8882 8883 __btrfs_releasepage(page, GFP_NOFS); 8884 } 8885 8886 ClearPageChecked(page); 8887 if (PagePrivate(page)) { 8888 ClearPagePrivate(page); 8889 set_page_private(page, 0); 8890 put_page(page); 8891 } 8892 } 8893 8894 /* 8895 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 8896 * called from a page fault handler when a page is first dirtied. Hence we must 8897 * be careful to check for EOF conditions here. We set the page up correctly 8898 * for a written page which means we get ENOSPC checking when writing into 8899 * holes and correct delalloc and unwritten extent mapping on filesystems that 8900 * support these features. 8901 * 8902 * We are not allowed to take the i_mutex here so we have to play games to 8903 * protect against truncate races as the page could now be beyond EOF. Because 8904 * vmtruncate() writes the inode size before removing pages, once we have the 8905 * page lock we can determine safely if the page is beyond EOF. If it is not 8906 * beyond EOF, then the page is guaranteed safe against truncation until we 8907 * unlock the page. 8908 */ 8909 int btrfs_page_mkwrite(struct vm_fault *vmf) 8910 { 8911 struct page *page = vmf->page; 8912 struct inode *inode = file_inode(vmf->vma->vm_file); 8913 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 8914 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 8915 struct btrfs_ordered_extent *ordered; 8916 struct extent_state *cached_state = NULL; 8917 char *kaddr; 8918 unsigned long zero_start; 8919 loff_t size; 8920 int ret; 8921 int reserved = 0; 8922 u64 reserved_space; 8923 u64 page_start; 8924 u64 page_end; 8925 u64 end; 8926 8927 reserved_space = PAGE_SIZE; 8928 8929 sb_start_pagefault(inode->i_sb); 8930 page_start = page_offset(page); 8931 page_end = page_start + PAGE_SIZE - 1; 8932 end = page_end; 8933 8934 /* 8935 * Reserving delalloc space after obtaining the page lock can lead to 8936 * deadlock. For example, if a dirty page is locked by this function 8937 * and the call to btrfs_delalloc_reserve_space() ends up triggering 8938 * dirty page write out, then the btrfs_writepage() function could 8939 * end up waiting indefinitely to get a lock on the page currently 8940 * being processed by btrfs_page_mkwrite() function. 8941 */ 8942 ret = btrfs_delalloc_reserve_space(inode, page_start, 8943 reserved_space); 8944 if (!ret) { 8945 ret = file_update_time(vmf->vma->vm_file); 8946 reserved = 1; 8947 } 8948 if (ret) { 8949 if (ret == -ENOMEM) 8950 ret = VM_FAULT_OOM; 8951 else /* -ENOSPC, -EIO, etc */ 8952 ret = VM_FAULT_SIGBUS; 8953 if (reserved) 8954 goto out; 8955 goto out_noreserve; 8956 } 8957 8958 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 8959 again: 8960 lock_page(page); 8961 size = i_size_read(inode); 8962 8963 if ((page->mapping != inode->i_mapping) || 8964 (page_start >= size)) { 8965 /* page got truncated out from underneath us */ 8966 goto out_unlock; 8967 } 8968 wait_on_page_writeback(page); 8969 8970 lock_extent_bits(io_tree, page_start, page_end, &cached_state); 8971 set_page_extent_mapped(page); 8972 8973 /* 8974 * we can't set the delalloc bits if there are pending ordered 8975 * extents. Drop our locks and wait for them to finish 8976 */ 8977 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start, 8978 PAGE_SIZE); 8979 if (ordered) { 8980 unlock_extent_cached(io_tree, page_start, page_end, 8981 &cached_state, GFP_NOFS); 8982 unlock_page(page); 8983 btrfs_start_ordered_extent(inode, ordered, 1); 8984 btrfs_put_ordered_extent(ordered); 8985 goto again; 8986 } 8987 8988 if (page->index == ((size - 1) >> PAGE_SHIFT)) { 8989 reserved_space = round_up(size - page_start, 8990 fs_info->sectorsize); 8991 if (reserved_space < PAGE_SIZE) { 8992 end = page_start + reserved_space - 1; 8993 spin_lock(&BTRFS_I(inode)->lock); 8994 BTRFS_I(inode)->outstanding_extents++; 8995 spin_unlock(&BTRFS_I(inode)->lock); 8996 btrfs_delalloc_release_space(inode, page_start, 8997 PAGE_SIZE - reserved_space); 8998 } 8999 } 9000 9001 /* 9002 * page_mkwrite gets called when the page is firstly dirtied after it's 9003 * faulted in, but write(2) could also dirty a page and set delalloc 9004 * bits, thus in this case for space account reason, we still need to 9005 * clear any delalloc bits within this page range since we have to 9006 * reserve data&meta space before lock_page() (see above comments). 9007 */ 9008 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end, 9009 EXTENT_DIRTY | EXTENT_DELALLOC | 9010 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 9011 0, 0, &cached_state, GFP_NOFS); 9012 9013 ret = btrfs_set_extent_delalloc(inode, page_start, end, 9014 &cached_state, 0); 9015 if (ret) { 9016 unlock_extent_cached(io_tree, page_start, page_end, 9017 &cached_state, GFP_NOFS); 9018 ret = VM_FAULT_SIGBUS; 9019 goto out_unlock; 9020 } 9021 ret = 0; 9022 9023 /* page is wholly or partially inside EOF */ 9024 if (page_start + PAGE_SIZE > size) 9025 zero_start = size & ~PAGE_MASK; 9026 else 9027 zero_start = PAGE_SIZE; 9028 9029 if (zero_start != PAGE_SIZE) { 9030 kaddr = kmap(page); 9031 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start); 9032 flush_dcache_page(page); 9033 kunmap(page); 9034 } 9035 ClearPageChecked(page); 9036 set_page_dirty(page); 9037 SetPageUptodate(page); 9038 9039 BTRFS_I(inode)->last_trans = fs_info->generation; 9040 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 9041 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 9042 9043 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 9044 9045 out_unlock: 9046 if (!ret) { 9047 sb_end_pagefault(inode->i_sb); 9048 return VM_FAULT_LOCKED; 9049 } 9050 unlock_page(page); 9051 out: 9052 btrfs_delalloc_release_space(inode, page_start, reserved_space); 9053 out_noreserve: 9054 sb_end_pagefault(inode->i_sb); 9055 return ret; 9056 } 9057 9058 static int btrfs_truncate(struct inode *inode) 9059 { 9060 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 9061 struct btrfs_root *root = BTRFS_I(inode)->root; 9062 struct btrfs_block_rsv *rsv; 9063 int ret = 0; 9064 int err = 0; 9065 struct btrfs_trans_handle *trans; 9066 u64 mask = fs_info->sectorsize - 1; 9067 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1); 9068 9069 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), 9070 (u64)-1); 9071 if (ret) 9072 return ret; 9073 9074 /* 9075 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have 9076 * 3 things going on here 9077 * 9078 * 1) We need to reserve space for our orphan item and the space to 9079 * delete our orphan item. Lord knows we don't want to have a dangling 9080 * orphan item because we didn't reserve space to remove it. 9081 * 9082 * 2) We need to reserve space to update our inode. 9083 * 9084 * 3) We need to have something to cache all the space that is going to 9085 * be free'd up by the truncate operation, but also have some slack 9086 * space reserved in case it uses space during the truncate (thank you 9087 * very much snapshotting). 9088 * 9089 * And we need these to all be separate. The fact is we can use a lot of 9090 * space doing the truncate, and we have no earthly idea how much space 9091 * we will use, so we need the truncate reservation to be separate so it 9092 * doesn't end up using space reserved for updating the inode or 9093 * removing the orphan item. We also need to be able to stop the 9094 * transaction and start a new one, which means we need to be able to 9095 * update the inode several times, and we have no idea of knowing how 9096 * many times that will be, so we can't just reserve 1 item for the 9097 * entirety of the operation, so that has to be done separately as well. 9098 * Then there is the orphan item, which does indeed need to be held on 9099 * to for the whole operation, and we need nobody to touch this reserved 9100 * space except the orphan code. 9101 * 9102 * So that leaves us with 9103 * 9104 * 1) root->orphan_block_rsv - for the orphan deletion. 9105 * 2) rsv - for the truncate reservation, which we will steal from the 9106 * transaction reservation. 9107 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 9108 * updating the inode. 9109 */ 9110 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); 9111 if (!rsv) 9112 return -ENOMEM; 9113 rsv->size = min_size; 9114 rsv->failfast = 1; 9115 9116 /* 9117 * 1 for the truncate slack space 9118 * 1 for updating the inode. 9119 */ 9120 trans = btrfs_start_transaction(root, 2); 9121 if (IS_ERR(trans)) { 9122 err = PTR_ERR(trans); 9123 goto out; 9124 } 9125 9126 /* Migrate the slack space for the truncate to our reserve */ 9127 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, 9128 min_size, 0); 9129 BUG_ON(ret); 9130 9131 /* 9132 * So if we truncate and then write and fsync we normally would just 9133 * write the extents that changed, which is a problem if we need to 9134 * first truncate that entire inode. So set this flag so we write out 9135 * all of the extents in the inode to the sync log so we're completely 9136 * safe. 9137 */ 9138 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 9139 trans->block_rsv = rsv; 9140 9141 while (1) { 9142 ret = btrfs_truncate_inode_items(trans, root, inode, 9143 inode->i_size, 9144 BTRFS_EXTENT_DATA_KEY); 9145 if (ret != -ENOSPC && ret != -EAGAIN) { 9146 err = ret; 9147 break; 9148 } 9149 9150 trans->block_rsv = &fs_info->trans_block_rsv; 9151 ret = btrfs_update_inode(trans, root, inode); 9152 if (ret) { 9153 err = ret; 9154 break; 9155 } 9156 9157 btrfs_end_transaction(trans); 9158 btrfs_btree_balance_dirty(fs_info); 9159 9160 trans = btrfs_start_transaction(root, 2); 9161 if (IS_ERR(trans)) { 9162 ret = err = PTR_ERR(trans); 9163 trans = NULL; 9164 break; 9165 } 9166 9167 btrfs_block_rsv_release(fs_info, rsv, -1); 9168 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, 9169 rsv, min_size, 0); 9170 BUG_ON(ret); /* shouldn't happen */ 9171 trans->block_rsv = rsv; 9172 } 9173 9174 if (ret == 0 && inode->i_nlink > 0) { 9175 trans->block_rsv = root->orphan_block_rsv; 9176 ret = btrfs_orphan_del(trans, BTRFS_I(inode)); 9177 if (ret) 9178 err = ret; 9179 } 9180 9181 if (trans) { 9182 trans->block_rsv = &fs_info->trans_block_rsv; 9183 ret = btrfs_update_inode(trans, root, inode); 9184 if (ret && !err) 9185 err = ret; 9186 9187 ret = btrfs_end_transaction(trans); 9188 btrfs_btree_balance_dirty(fs_info); 9189 } 9190 out: 9191 btrfs_free_block_rsv(fs_info, rsv); 9192 9193 if (ret && !err) 9194 err = ret; 9195 9196 return err; 9197 } 9198 9199 /* 9200 * create a new subvolume directory/inode (helper for the ioctl). 9201 */ 9202 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 9203 struct btrfs_root *new_root, 9204 struct btrfs_root *parent_root, 9205 u64 new_dirid) 9206 { 9207 struct inode *inode; 9208 int err; 9209 u64 index = 0; 9210 9211 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 9212 new_dirid, new_dirid, 9213 S_IFDIR | (~current_umask() & S_IRWXUGO), 9214 &index); 9215 if (IS_ERR(inode)) 9216 return PTR_ERR(inode); 9217 inode->i_op = &btrfs_dir_inode_operations; 9218 inode->i_fop = &btrfs_dir_file_operations; 9219 9220 set_nlink(inode, 1); 9221 btrfs_i_size_write(BTRFS_I(inode), 0); 9222 unlock_new_inode(inode); 9223 9224 err = btrfs_subvol_inherit_props(trans, new_root, parent_root); 9225 if (err) 9226 btrfs_err(new_root->fs_info, 9227 "error inheriting subvolume %llu properties: %d", 9228 new_root->root_key.objectid, err); 9229 9230 err = btrfs_update_inode(trans, new_root, inode); 9231 9232 iput(inode); 9233 return err; 9234 } 9235 9236 struct inode *btrfs_alloc_inode(struct super_block *sb) 9237 { 9238 struct btrfs_inode *ei; 9239 struct inode *inode; 9240 9241 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 9242 if (!ei) 9243 return NULL; 9244 9245 ei->root = NULL; 9246 ei->generation = 0; 9247 ei->last_trans = 0; 9248 ei->last_sub_trans = 0; 9249 ei->logged_trans = 0; 9250 ei->delalloc_bytes = 0; 9251 ei->defrag_bytes = 0; 9252 ei->disk_i_size = 0; 9253 ei->flags = 0; 9254 ei->csum_bytes = 0; 9255 ei->index_cnt = (u64)-1; 9256 ei->dir_index = 0; 9257 ei->last_unlink_trans = 0; 9258 ei->last_log_commit = 0; 9259 ei->delayed_iput_count = 0; 9260 9261 spin_lock_init(&ei->lock); 9262 ei->outstanding_extents = 0; 9263 ei->reserved_extents = 0; 9264 9265 ei->runtime_flags = 0; 9266 ei->force_compress = BTRFS_COMPRESS_NONE; 9267 9268 ei->delayed_node = NULL; 9269 9270 ei->i_otime.tv_sec = 0; 9271 ei->i_otime.tv_nsec = 0; 9272 9273 inode = &ei->vfs_inode; 9274 extent_map_tree_init(&ei->extent_tree); 9275 extent_io_tree_init(&ei->io_tree, &inode->i_data); 9276 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 9277 ei->io_tree.track_uptodate = 1; 9278 ei->io_failure_tree.track_uptodate = 1; 9279 atomic_set(&ei->sync_writers, 0); 9280 mutex_init(&ei->log_mutex); 9281 mutex_init(&ei->delalloc_mutex); 9282 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 9283 INIT_LIST_HEAD(&ei->delalloc_inodes); 9284 INIT_LIST_HEAD(&ei->delayed_iput); 9285 RB_CLEAR_NODE(&ei->rb_node); 9286 init_rwsem(&ei->dio_sem); 9287 9288 return inode; 9289 } 9290 9291 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 9292 void btrfs_test_destroy_inode(struct inode *inode) 9293 { 9294 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0); 9295 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 9296 } 9297 #endif 9298 9299 static void btrfs_i_callback(struct rcu_head *head) 9300 { 9301 struct inode *inode = container_of(head, struct inode, i_rcu); 9302 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 9303 } 9304 9305 void btrfs_destroy_inode(struct inode *inode) 9306 { 9307 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 9308 struct btrfs_ordered_extent *ordered; 9309 struct btrfs_root *root = BTRFS_I(inode)->root; 9310 9311 WARN_ON(!hlist_empty(&inode->i_dentry)); 9312 WARN_ON(inode->i_data.nrpages); 9313 WARN_ON(BTRFS_I(inode)->outstanding_extents); 9314 WARN_ON(BTRFS_I(inode)->reserved_extents); 9315 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 9316 WARN_ON(BTRFS_I(inode)->csum_bytes); 9317 WARN_ON(BTRFS_I(inode)->defrag_bytes); 9318 9319 /* 9320 * This can happen where we create an inode, but somebody else also 9321 * created the same inode and we need to destroy the one we already 9322 * created. 9323 */ 9324 if (!root) 9325 goto free; 9326 9327 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 9328 &BTRFS_I(inode)->runtime_flags)) { 9329 btrfs_info(fs_info, "inode %llu still on the orphan list", 9330 btrfs_ino(BTRFS_I(inode))); 9331 atomic_dec(&root->orphan_inodes); 9332 } 9333 9334 while (1) { 9335 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 9336 if (!ordered) 9337 break; 9338 else { 9339 btrfs_err(fs_info, 9340 "found ordered extent %llu %llu on inode cleanup", 9341 ordered->file_offset, ordered->len); 9342 btrfs_remove_ordered_extent(inode, ordered); 9343 btrfs_put_ordered_extent(ordered); 9344 btrfs_put_ordered_extent(ordered); 9345 } 9346 } 9347 btrfs_qgroup_check_reserved_leak(inode); 9348 inode_tree_del(inode); 9349 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0); 9350 free: 9351 call_rcu(&inode->i_rcu, btrfs_i_callback); 9352 } 9353 9354 int btrfs_drop_inode(struct inode *inode) 9355 { 9356 struct btrfs_root *root = BTRFS_I(inode)->root; 9357 9358 if (root == NULL) 9359 return 1; 9360 9361 /* the snap/subvol tree is on deleting */ 9362 if (btrfs_root_refs(&root->root_item) == 0) 9363 return 1; 9364 else 9365 return generic_drop_inode(inode); 9366 } 9367 9368 static void init_once(void *foo) 9369 { 9370 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 9371 9372 inode_init_once(&ei->vfs_inode); 9373 } 9374 9375 void btrfs_destroy_cachep(void) 9376 { 9377 /* 9378 * Make sure all delayed rcu free inodes are flushed before we 9379 * destroy cache. 9380 */ 9381 rcu_barrier(); 9382 kmem_cache_destroy(btrfs_inode_cachep); 9383 kmem_cache_destroy(btrfs_trans_handle_cachep); 9384 kmem_cache_destroy(btrfs_transaction_cachep); 9385 kmem_cache_destroy(btrfs_path_cachep); 9386 kmem_cache_destroy(btrfs_free_space_cachep); 9387 } 9388 9389 int btrfs_init_cachep(void) 9390 { 9391 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 9392 sizeof(struct btrfs_inode), 0, 9393 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT, 9394 init_once); 9395 if (!btrfs_inode_cachep) 9396 goto fail; 9397 9398 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 9399 sizeof(struct btrfs_trans_handle), 0, 9400 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL); 9401 if (!btrfs_trans_handle_cachep) 9402 goto fail; 9403 9404 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 9405 sizeof(struct btrfs_transaction), 0, 9406 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL); 9407 if (!btrfs_transaction_cachep) 9408 goto fail; 9409 9410 btrfs_path_cachep = kmem_cache_create("btrfs_path", 9411 sizeof(struct btrfs_path), 0, 9412 SLAB_MEM_SPREAD, NULL); 9413 if (!btrfs_path_cachep) 9414 goto fail; 9415 9416 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 9417 sizeof(struct btrfs_free_space), 0, 9418 SLAB_MEM_SPREAD, NULL); 9419 if (!btrfs_free_space_cachep) 9420 goto fail; 9421 9422 return 0; 9423 fail: 9424 btrfs_destroy_cachep(); 9425 return -ENOMEM; 9426 } 9427 9428 static int btrfs_getattr(const struct path *path, struct kstat *stat, 9429 u32 request_mask, unsigned int flags) 9430 { 9431 u64 delalloc_bytes; 9432 struct inode *inode = d_inode(path->dentry); 9433 u32 blocksize = inode->i_sb->s_blocksize; 9434 9435 generic_fillattr(inode, stat); 9436 stat->dev = BTRFS_I(inode)->root->anon_dev; 9437 9438 spin_lock(&BTRFS_I(inode)->lock); 9439 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 9440 spin_unlock(&BTRFS_I(inode)->lock); 9441 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 9442 ALIGN(delalloc_bytes, blocksize)) >> 9; 9443 return 0; 9444 } 9445 9446 static int btrfs_rename_exchange(struct inode *old_dir, 9447 struct dentry *old_dentry, 9448 struct inode *new_dir, 9449 struct dentry *new_dentry) 9450 { 9451 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb); 9452 struct btrfs_trans_handle *trans; 9453 struct btrfs_root *root = BTRFS_I(old_dir)->root; 9454 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 9455 struct inode *new_inode = new_dentry->d_inode; 9456 struct inode *old_inode = old_dentry->d_inode; 9457 struct timespec ctime = current_time(old_inode); 9458 struct dentry *parent; 9459 u64 old_ino = btrfs_ino(BTRFS_I(old_inode)); 9460 u64 new_ino = btrfs_ino(BTRFS_I(new_inode)); 9461 u64 old_idx = 0; 9462 u64 new_idx = 0; 9463 u64 root_objectid; 9464 int ret; 9465 bool root_log_pinned = false; 9466 bool dest_log_pinned = false; 9467 9468 /* we only allow rename subvolume link between subvolumes */ 9469 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 9470 return -EXDEV; 9471 9472 /* close the race window with snapshot create/destroy ioctl */ 9473 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9474 down_read(&fs_info->subvol_sem); 9475 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) 9476 down_read(&fs_info->subvol_sem); 9477 9478 /* 9479 * We want to reserve the absolute worst case amount of items. So if 9480 * both inodes are subvols and we need to unlink them then that would 9481 * require 4 item modifications, but if they are both normal inodes it 9482 * would require 5 item modifications, so we'll assume their normal 9483 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items 9484 * should cover the worst case number of items we'll modify. 9485 */ 9486 trans = btrfs_start_transaction(root, 12); 9487 if (IS_ERR(trans)) { 9488 ret = PTR_ERR(trans); 9489 goto out_notrans; 9490 } 9491 9492 /* 9493 * We need to find a free sequence number both in the source and 9494 * in the destination directory for the exchange. 9495 */ 9496 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx); 9497 if (ret) 9498 goto out_fail; 9499 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx); 9500 if (ret) 9501 goto out_fail; 9502 9503 BTRFS_I(old_inode)->dir_index = 0ULL; 9504 BTRFS_I(new_inode)->dir_index = 0ULL; 9505 9506 /* Reference for the source. */ 9507 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) { 9508 /* force full log commit if subvolume involved. */ 9509 btrfs_set_log_full_commit(fs_info, trans); 9510 } else { 9511 btrfs_pin_log_trans(root); 9512 root_log_pinned = true; 9513 ret = btrfs_insert_inode_ref(trans, dest, 9514 new_dentry->d_name.name, 9515 new_dentry->d_name.len, 9516 old_ino, 9517 btrfs_ino(BTRFS_I(new_dir)), 9518 old_idx); 9519 if (ret) 9520 goto out_fail; 9521 } 9522 9523 /* And now for the dest. */ 9524 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) { 9525 /* force full log commit if subvolume involved. */ 9526 btrfs_set_log_full_commit(fs_info, trans); 9527 } else { 9528 btrfs_pin_log_trans(dest); 9529 dest_log_pinned = true; 9530 ret = btrfs_insert_inode_ref(trans, root, 9531 old_dentry->d_name.name, 9532 old_dentry->d_name.len, 9533 new_ino, 9534 btrfs_ino(BTRFS_I(old_dir)), 9535 new_idx); 9536 if (ret) 9537 goto out_fail; 9538 } 9539 9540 /* Update inode version and ctime/mtime. */ 9541 inode_inc_iversion(old_dir); 9542 inode_inc_iversion(new_dir); 9543 inode_inc_iversion(old_inode); 9544 inode_inc_iversion(new_inode); 9545 old_dir->i_ctime = old_dir->i_mtime = ctime; 9546 new_dir->i_ctime = new_dir->i_mtime = ctime; 9547 old_inode->i_ctime = ctime; 9548 new_inode->i_ctime = ctime; 9549 9550 if (old_dentry->d_parent != new_dentry->d_parent) { 9551 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir), 9552 BTRFS_I(old_inode), 1); 9553 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir), 9554 BTRFS_I(new_inode), 1); 9555 } 9556 9557 /* src is a subvolume */ 9558 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) { 9559 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 9560 ret = btrfs_unlink_subvol(trans, root, old_dir, 9561 root_objectid, 9562 old_dentry->d_name.name, 9563 old_dentry->d_name.len); 9564 } else { /* src is an inode */ 9565 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir), 9566 BTRFS_I(old_dentry->d_inode), 9567 old_dentry->d_name.name, 9568 old_dentry->d_name.len); 9569 if (!ret) 9570 ret = btrfs_update_inode(trans, root, old_inode); 9571 } 9572 if (ret) { 9573 btrfs_abort_transaction(trans, ret); 9574 goto out_fail; 9575 } 9576 9577 /* dest is a subvolume */ 9578 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) { 9579 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid; 9580 ret = btrfs_unlink_subvol(trans, dest, new_dir, 9581 root_objectid, 9582 new_dentry->d_name.name, 9583 new_dentry->d_name.len); 9584 } else { /* dest is an inode */ 9585 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir), 9586 BTRFS_I(new_dentry->d_inode), 9587 new_dentry->d_name.name, 9588 new_dentry->d_name.len); 9589 if (!ret) 9590 ret = btrfs_update_inode(trans, dest, new_inode); 9591 } 9592 if (ret) { 9593 btrfs_abort_transaction(trans, ret); 9594 goto out_fail; 9595 } 9596 9597 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode), 9598 new_dentry->d_name.name, 9599 new_dentry->d_name.len, 0, old_idx); 9600 if (ret) { 9601 btrfs_abort_transaction(trans, ret); 9602 goto out_fail; 9603 } 9604 9605 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode), 9606 old_dentry->d_name.name, 9607 old_dentry->d_name.len, 0, new_idx); 9608 if (ret) { 9609 btrfs_abort_transaction(trans, ret); 9610 goto out_fail; 9611 } 9612 9613 if (old_inode->i_nlink == 1) 9614 BTRFS_I(old_inode)->dir_index = old_idx; 9615 if (new_inode->i_nlink == 1) 9616 BTRFS_I(new_inode)->dir_index = new_idx; 9617 9618 if (root_log_pinned) { 9619 parent = new_dentry->d_parent; 9620 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir), 9621 parent); 9622 btrfs_end_log_trans(root); 9623 root_log_pinned = false; 9624 } 9625 if (dest_log_pinned) { 9626 parent = old_dentry->d_parent; 9627 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir), 9628 parent); 9629 btrfs_end_log_trans(dest); 9630 dest_log_pinned = false; 9631 } 9632 out_fail: 9633 /* 9634 * If we have pinned a log and an error happened, we unpin tasks 9635 * trying to sync the log and force them to fallback to a transaction 9636 * commit if the log currently contains any of the inodes involved in 9637 * this rename operation (to ensure we do not persist a log with an 9638 * inconsistent state for any of these inodes or leading to any 9639 * inconsistencies when replayed). If the transaction was aborted, the 9640 * abortion reason is propagated to userspace when attempting to commit 9641 * the transaction. If the log does not contain any of these inodes, we 9642 * allow the tasks to sync it. 9643 */ 9644 if (ret && (root_log_pinned || dest_log_pinned)) { 9645 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) || 9646 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) || 9647 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) || 9648 (new_inode && 9649 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))) 9650 btrfs_set_log_full_commit(fs_info, trans); 9651 9652 if (root_log_pinned) { 9653 btrfs_end_log_trans(root); 9654 root_log_pinned = false; 9655 } 9656 if (dest_log_pinned) { 9657 btrfs_end_log_trans(dest); 9658 dest_log_pinned = false; 9659 } 9660 } 9661 ret = btrfs_end_transaction(trans); 9662 out_notrans: 9663 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) 9664 up_read(&fs_info->subvol_sem); 9665 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9666 up_read(&fs_info->subvol_sem); 9667 9668 return ret; 9669 } 9670 9671 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans, 9672 struct btrfs_root *root, 9673 struct inode *dir, 9674 struct dentry *dentry) 9675 { 9676 int ret; 9677 struct inode *inode; 9678 u64 objectid; 9679 u64 index; 9680 9681 ret = btrfs_find_free_ino(root, &objectid); 9682 if (ret) 9683 return ret; 9684 9685 inode = btrfs_new_inode(trans, root, dir, 9686 dentry->d_name.name, 9687 dentry->d_name.len, 9688 btrfs_ino(BTRFS_I(dir)), 9689 objectid, 9690 S_IFCHR | WHITEOUT_MODE, 9691 &index); 9692 9693 if (IS_ERR(inode)) { 9694 ret = PTR_ERR(inode); 9695 return ret; 9696 } 9697 9698 inode->i_op = &btrfs_special_inode_operations; 9699 init_special_inode(inode, inode->i_mode, 9700 WHITEOUT_DEV); 9701 9702 ret = btrfs_init_inode_security(trans, inode, dir, 9703 &dentry->d_name); 9704 if (ret) 9705 goto out; 9706 9707 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, 9708 BTRFS_I(inode), 0, index); 9709 if (ret) 9710 goto out; 9711 9712 ret = btrfs_update_inode(trans, root, inode); 9713 out: 9714 unlock_new_inode(inode); 9715 if (ret) 9716 inode_dec_link_count(inode); 9717 iput(inode); 9718 9719 return ret; 9720 } 9721 9722 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 9723 struct inode *new_dir, struct dentry *new_dentry, 9724 unsigned int flags) 9725 { 9726 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb); 9727 struct btrfs_trans_handle *trans; 9728 unsigned int trans_num_items; 9729 struct btrfs_root *root = BTRFS_I(old_dir)->root; 9730 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 9731 struct inode *new_inode = d_inode(new_dentry); 9732 struct inode *old_inode = d_inode(old_dentry); 9733 u64 index = 0; 9734 u64 root_objectid; 9735 int ret; 9736 u64 old_ino = btrfs_ino(BTRFS_I(old_inode)); 9737 bool log_pinned = false; 9738 9739 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 9740 return -EPERM; 9741 9742 /* we only allow rename subvolume link between subvolumes */ 9743 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 9744 return -EXDEV; 9745 9746 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 9747 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID)) 9748 return -ENOTEMPTY; 9749 9750 if (S_ISDIR(old_inode->i_mode) && new_inode && 9751 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 9752 return -ENOTEMPTY; 9753 9754 9755 /* check for collisions, even if the name isn't there */ 9756 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, 9757 new_dentry->d_name.name, 9758 new_dentry->d_name.len); 9759 9760 if (ret) { 9761 if (ret == -EEXIST) { 9762 /* we shouldn't get 9763 * eexist without a new_inode */ 9764 if (WARN_ON(!new_inode)) { 9765 return ret; 9766 } 9767 } else { 9768 /* maybe -EOVERFLOW */ 9769 return ret; 9770 } 9771 } 9772 ret = 0; 9773 9774 /* 9775 * we're using rename to replace one file with another. Start IO on it 9776 * now so we don't add too much work to the end of the transaction 9777 */ 9778 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size) 9779 filemap_flush(old_inode->i_mapping); 9780 9781 /* close the racy window with snapshot create/destroy ioctl */ 9782 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9783 down_read(&fs_info->subvol_sem); 9784 /* 9785 * We want to reserve the absolute worst case amount of items. So if 9786 * both inodes are subvols and we need to unlink them then that would 9787 * require 4 item modifications, but if they are both normal inodes it 9788 * would require 5 item modifications, so we'll assume they are normal 9789 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 9790 * should cover the worst case number of items we'll modify. 9791 * If our rename has the whiteout flag, we need more 5 units for the 9792 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item 9793 * when selinux is enabled). 9794 */ 9795 trans_num_items = 11; 9796 if (flags & RENAME_WHITEOUT) 9797 trans_num_items += 5; 9798 trans = btrfs_start_transaction(root, trans_num_items); 9799 if (IS_ERR(trans)) { 9800 ret = PTR_ERR(trans); 9801 goto out_notrans; 9802 } 9803 9804 if (dest != root) 9805 btrfs_record_root_in_trans(trans, dest); 9806 9807 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index); 9808 if (ret) 9809 goto out_fail; 9810 9811 BTRFS_I(old_inode)->dir_index = 0ULL; 9812 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 9813 /* force full log commit if subvolume involved. */ 9814 btrfs_set_log_full_commit(fs_info, trans); 9815 } else { 9816 btrfs_pin_log_trans(root); 9817 log_pinned = true; 9818 ret = btrfs_insert_inode_ref(trans, dest, 9819 new_dentry->d_name.name, 9820 new_dentry->d_name.len, 9821 old_ino, 9822 btrfs_ino(BTRFS_I(new_dir)), index); 9823 if (ret) 9824 goto out_fail; 9825 } 9826 9827 inode_inc_iversion(old_dir); 9828 inode_inc_iversion(new_dir); 9829 inode_inc_iversion(old_inode); 9830 old_dir->i_ctime = old_dir->i_mtime = 9831 new_dir->i_ctime = new_dir->i_mtime = 9832 old_inode->i_ctime = current_time(old_dir); 9833 9834 if (old_dentry->d_parent != new_dentry->d_parent) 9835 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir), 9836 BTRFS_I(old_inode), 1); 9837 9838 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 9839 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 9840 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 9841 old_dentry->d_name.name, 9842 old_dentry->d_name.len); 9843 } else { 9844 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir), 9845 BTRFS_I(d_inode(old_dentry)), 9846 old_dentry->d_name.name, 9847 old_dentry->d_name.len); 9848 if (!ret) 9849 ret = btrfs_update_inode(trans, root, old_inode); 9850 } 9851 if (ret) { 9852 btrfs_abort_transaction(trans, ret); 9853 goto out_fail; 9854 } 9855 9856 if (new_inode) { 9857 inode_inc_iversion(new_inode); 9858 new_inode->i_ctime = current_time(new_inode); 9859 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) == 9860 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 9861 root_objectid = BTRFS_I(new_inode)->location.objectid; 9862 ret = btrfs_unlink_subvol(trans, dest, new_dir, 9863 root_objectid, 9864 new_dentry->d_name.name, 9865 new_dentry->d_name.len); 9866 BUG_ON(new_inode->i_nlink == 0); 9867 } else { 9868 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir), 9869 BTRFS_I(d_inode(new_dentry)), 9870 new_dentry->d_name.name, 9871 new_dentry->d_name.len); 9872 } 9873 if (!ret && new_inode->i_nlink == 0) 9874 ret = btrfs_orphan_add(trans, 9875 BTRFS_I(d_inode(new_dentry))); 9876 if (ret) { 9877 btrfs_abort_transaction(trans, ret); 9878 goto out_fail; 9879 } 9880 } 9881 9882 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode), 9883 new_dentry->d_name.name, 9884 new_dentry->d_name.len, 0, index); 9885 if (ret) { 9886 btrfs_abort_transaction(trans, ret); 9887 goto out_fail; 9888 } 9889 9890 if (old_inode->i_nlink == 1) 9891 BTRFS_I(old_inode)->dir_index = index; 9892 9893 if (log_pinned) { 9894 struct dentry *parent = new_dentry->d_parent; 9895 9896 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir), 9897 parent); 9898 btrfs_end_log_trans(root); 9899 log_pinned = false; 9900 } 9901 9902 if (flags & RENAME_WHITEOUT) { 9903 ret = btrfs_whiteout_for_rename(trans, root, old_dir, 9904 old_dentry); 9905 9906 if (ret) { 9907 btrfs_abort_transaction(trans, ret); 9908 goto out_fail; 9909 } 9910 } 9911 out_fail: 9912 /* 9913 * If we have pinned the log and an error happened, we unpin tasks 9914 * trying to sync the log and force them to fallback to a transaction 9915 * commit if the log currently contains any of the inodes involved in 9916 * this rename operation (to ensure we do not persist a log with an 9917 * inconsistent state for any of these inodes or leading to any 9918 * inconsistencies when replayed). If the transaction was aborted, the 9919 * abortion reason is propagated to userspace when attempting to commit 9920 * the transaction. If the log does not contain any of these inodes, we 9921 * allow the tasks to sync it. 9922 */ 9923 if (ret && log_pinned) { 9924 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) || 9925 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) || 9926 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) || 9927 (new_inode && 9928 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))) 9929 btrfs_set_log_full_commit(fs_info, trans); 9930 9931 btrfs_end_log_trans(root); 9932 log_pinned = false; 9933 } 9934 btrfs_end_transaction(trans); 9935 out_notrans: 9936 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9937 up_read(&fs_info->subvol_sem); 9938 9939 return ret; 9940 } 9941 9942 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, 9943 struct inode *new_dir, struct dentry *new_dentry, 9944 unsigned int flags) 9945 { 9946 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 9947 return -EINVAL; 9948 9949 if (flags & RENAME_EXCHANGE) 9950 return btrfs_rename_exchange(old_dir, old_dentry, new_dir, 9951 new_dentry); 9952 9953 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 9954 } 9955 9956 static void btrfs_run_delalloc_work(struct btrfs_work *work) 9957 { 9958 struct btrfs_delalloc_work *delalloc_work; 9959 struct inode *inode; 9960 9961 delalloc_work = container_of(work, struct btrfs_delalloc_work, 9962 work); 9963 inode = delalloc_work->inode; 9964 filemap_flush(inode->i_mapping); 9965 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 9966 &BTRFS_I(inode)->runtime_flags)) 9967 filemap_flush(inode->i_mapping); 9968 9969 if (delalloc_work->delay_iput) 9970 btrfs_add_delayed_iput(inode); 9971 else 9972 iput(inode); 9973 complete(&delalloc_work->completion); 9974 } 9975 9976 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 9977 int delay_iput) 9978 { 9979 struct btrfs_delalloc_work *work; 9980 9981 work = kmalloc(sizeof(*work), GFP_NOFS); 9982 if (!work) 9983 return NULL; 9984 9985 init_completion(&work->completion); 9986 INIT_LIST_HEAD(&work->list); 9987 work->inode = inode; 9988 work->delay_iput = delay_iput; 9989 WARN_ON_ONCE(!inode); 9990 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper, 9991 btrfs_run_delalloc_work, NULL, NULL); 9992 9993 return work; 9994 } 9995 9996 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 9997 { 9998 wait_for_completion(&work->completion); 9999 kfree(work); 10000 } 10001 10002 /* 10003 * some fairly slow code that needs optimization. This walks the list 10004 * of all the inodes with pending delalloc and forces them to disk. 10005 */ 10006 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput, 10007 int nr) 10008 { 10009 struct btrfs_inode *binode; 10010 struct inode *inode; 10011 struct btrfs_delalloc_work *work, *next; 10012 struct list_head works; 10013 struct list_head splice; 10014 int ret = 0; 10015 10016 INIT_LIST_HEAD(&works); 10017 INIT_LIST_HEAD(&splice); 10018 10019 mutex_lock(&root->delalloc_mutex); 10020 spin_lock(&root->delalloc_lock); 10021 list_splice_init(&root->delalloc_inodes, &splice); 10022 while (!list_empty(&splice)) { 10023 binode = list_entry(splice.next, struct btrfs_inode, 10024 delalloc_inodes); 10025 10026 list_move_tail(&binode->delalloc_inodes, 10027 &root->delalloc_inodes); 10028 inode = igrab(&binode->vfs_inode); 10029 if (!inode) { 10030 cond_resched_lock(&root->delalloc_lock); 10031 continue; 10032 } 10033 spin_unlock(&root->delalloc_lock); 10034 10035 work = btrfs_alloc_delalloc_work(inode, delay_iput); 10036 if (!work) { 10037 if (delay_iput) 10038 btrfs_add_delayed_iput(inode); 10039 else 10040 iput(inode); 10041 ret = -ENOMEM; 10042 goto out; 10043 } 10044 list_add_tail(&work->list, &works); 10045 btrfs_queue_work(root->fs_info->flush_workers, 10046 &work->work); 10047 ret++; 10048 if (nr != -1 && ret >= nr) 10049 goto out; 10050 cond_resched(); 10051 spin_lock(&root->delalloc_lock); 10052 } 10053 spin_unlock(&root->delalloc_lock); 10054 10055 out: 10056 list_for_each_entry_safe(work, next, &works, list) { 10057 list_del_init(&work->list); 10058 btrfs_wait_and_free_delalloc_work(work); 10059 } 10060 10061 if (!list_empty_careful(&splice)) { 10062 spin_lock(&root->delalloc_lock); 10063 list_splice_tail(&splice, &root->delalloc_inodes); 10064 spin_unlock(&root->delalloc_lock); 10065 } 10066 mutex_unlock(&root->delalloc_mutex); 10067 return ret; 10068 } 10069 10070 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 10071 { 10072 struct btrfs_fs_info *fs_info = root->fs_info; 10073 int ret; 10074 10075 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 10076 return -EROFS; 10077 10078 ret = __start_delalloc_inodes(root, delay_iput, -1); 10079 if (ret > 0) 10080 ret = 0; 10081 /* 10082 * the filemap_flush will queue IO into the worker threads, but 10083 * we have to make sure the IO is actually started and that 10084 * ordered extents get created before we return 10085 */ 10086 atomic_inc(&fs_info->async_submit_draining); 10087 while (atomic_read(&fs_info->nr_async_submits) || 10088 atomic_read(&fs_info->async_delalloc_pages)) { 10089 wait_event(fs_info->async_submit_wait, 10090 (atomic_read(&fs_info->nr_async_submits) == 0 && 10091 atomic_read(&fs_info->async_delalloc_pages) == 0)); 10092 } 10093 atomic_dec(&fs_info->async_submit_draining); 10094 return ret; 10095 } 10096 10097 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput, 10098 int nr) 10099 { 10100 struct btrfs_root *root; 10101 struct list_head splice; 10102 int ret; 10103 10104 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 10105 return -EROFS; 10106 10107 INIT_LIST_HEAD(&splice); 10108 10109 mutex_lock(&fs_info->delalloc_root_mutex); 10110 spin_lock(&fs_info->delalloc_root_lock); 10111 list_splice_init(&fs_info->delalloc_roots, &splice); 10112 while (!list_empty(&splice) && nr) { 10113 root = list_first_entry(&splice, struct btrfs_root, 10114 delalloc_root); 10115 root = btrfs_grab_fs_root(root); 10116 BUG_ON(!root); 10117 list_move_tail(&root->delalloc_root, 10118 &fs_info->delalloc_roots); 10119 spin_unlock(&fs_info->delalloc_root_lock); 10120 10121 ret = __start_delalloc_inodes(root, delay_iput, nr); 10122 btrfs_put_fs_root(root); 10123 if (ret < 0) 10124 goto out; 10125 10126 if (nr != -1) { 10127 nr -= ret; 10128 WARN_ON(nr < 0); 10129 } 10130 spin_lock(&fs_info->delalloc_root_lock); 10131 } 10132 spin_unlock(&fs_info->delalloc_root_lock); 10133 10134 ret = 0; 10135 atomic_inc(&fs_info->async_submit_draining); 10136 while (atomic_read(&fs_info->nr_async_submits) || 10137 atomic_read(&fs_info->async_delalloc_pages)) { 10138 wait_event(fs_info->async_submit_wait, 10139 (atomic_read(&fs_info->nr_async_submits) == 0 && 10140 atomic_read(&fs_info->async_delalloc_pages) == 0)); 10141 } 10142 atomic_dec(&fs_info->async_submit_draining); 10143 out: 10144 if (!list_empty_careful(&splice)) { 10145 spin_lock(&fs_info->delalloc_root_lock); 10146 list_splice_tail(&splice, &fs_info->delalloc_roots); 10147 spin_unlock(&fs_info->delalloc_root_lock); 10148 } 10149 mutex_unlock(&fs_info->delalloc_root_mutex); 10150 return ret; 10151 } 10152 10153 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 10154 const char *symname) 10155 { 10156 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 10157 struct btrfs_trans_handle *trans; 10158 struct btrfs_root *root = BTRFS_I(dir)->root; 10159 struct btrfs_path *path; 10160 struct btrfs_key key; 10161 struct inode *inode = NULL; 10162 int err; 10163 int drop_inode = 0; 10164 u64 objectid; 10165 u64 index = 0; 10166 int name_len; 10167 int datasize; 10168 unsigned long ptr; 10169 struct btrfs_file_extent_item *ei; 10170 struct extent_buffer *leaf; 10171 10172 name_len = strlen(symname); 10173 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info)) 10174 return -ENAMETOOLONG; 10175 10176 /* 10177 * 2 items for inode item and ref 10178 * 2 items for dir items 10179 * 1 item for updating parent inode item 10180 * 1 item for the inline extent item 10181 * 1 item for xattr if selinux is on 10182 */ 10183 trans = btrfs_start_transaction(root, 7); 10184 if (IS_ERR(trans)) 10185 return PTR_ERR(trans); 10186 10187 err = btrfs_find_free_ino(root, &objectid); 10188 if (err) 10189 goto out_unlock; 10190 10191 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 10192 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), 10193 objectid, S_IFLNK|S_IRWXUGO, &index); 10194 if (IS_ERR(inode)) { 10195 err = PTR_ERR(inode); 10196 goto out_unlock; 10197 } 10198 10199 /* 10200 * If the active LSM wants to access the inode during 10201 * d_instantiate it needs these. Smack checks to see 10202 * if the filesystem supports xattrs by looking at the 10203 * ops vector. 10204 */ 10205 inode->i_fop = &btrfs_file_operations; 10206 inode->i_op = &btrfs_file_inode_operations; 10207 inode->i_mapping->a_ops = &btrfs_aops; 10208 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 10209 10210 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 10211 if (err) 10212 goto out_unlock_inode; 10213 10214 path = btrfs_alloc_path(); 10215 if (!path) { 10216 err = -ENOMEM; 10217 goto out_unlock_inode; 10218 } 10219 key.objectid = btrfs_ino(BTRFS_I(inode)); 10220 key.offset = 0; 10221 key.type = BTRFS_EXTENT_DATA_KEY; 10222 datasize = btrfs_file_extent_calc_inline_size(name_len); 10223 err = btrfs_insert_empty_item(trans, root, path, &key, 10224 datasize); 10225 if (err) { 10226 btrfs_free_path(path); 10227 goto out_unlock_inode; 10228 } 10229 leaf = path->nodes[0]; 10230 ei = btrfs_item_ptr(leaf, path->slots[0], 10231 struct btrfs_file_extent_item); 10232 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 10233 btrfs_set_file_extent_type(leaf, ei, 10234 BTRFS_FILE_EXTENT_INLINE); 10235 btrfs_set_file_extent_encryption(leaf, ei, 0); 10236 btrfs_set_file_extent_compression(leaf, ei, 0); 10237 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 10238 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 10239 10240 ptr = btrfs_file_extent_inline_start(ei); 10241 write_extent_buffer(leaf, symname, ptr, name_len); 10242 btrfs_mark_buffer_dirty(leaf); 10243 btrfs_free_path(path); 10244 10245 inode->i_op = &btrfs_symlink_inode_operations; 10246 inode_nohighmem(inode); 10247 inode->i_mapping->a_ops = &btrfs_symlink_aops; 10248 inode_set_bytes(inode, name_len); 10249 btrfs_i_size_write(BTRFS_I(inode), name_len); 10250 err = btrfs_update_inode(trans, root, inode); 10251 /* 10252 * Last step, add directory indexes for our symlink inode. This is the 10253 * last step to avoid extra cleanup of these indexes if an error happens 10254 * elsewhere above. 10255 */ 10256 if (!err) 10257 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, 10258 BTRFS_I(inode), 0, index); 10259 if (err) { 10260 drop_inode = 1; 10261 goto out_unlock_inode; 10262 } 10263 10264 unlock_new_inode(inode); 10265 d_instantiate(dentry, inode); 10266 10267 out_unlock: 10268 btrfs_end_transaction(trans); 10269 if (drop_inode) { 10270 inode_dec_link_count(inode); 10271 iput(inode); 10272 } 10273 btrfs_btree_balance_dirty(fs_info); 10274 return err; 10275 10276 out_unlock_inode: 10277 drop_inode = 1; 10278 unlock_new_inode(inode); 10279 goto out_unlock; 10280 } 10281 10282 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 10283 u64 start, u64 num_bytes, u64 min_size, 10284 loff_t actual_len, u64 *alloc_hint, 10285 struct btrfs_trans_handle *trans) 10286 { 10287 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 10288 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 10289 struct extent_map *em; 10290 struct btrfs_root *root = BTRFS_I(inode)->root; 10291 struct btrfs_key ins; 10292 u64 cur_offset = start; 10293 u64 i_size; 10294 u64 cur_bytes; 10295 u64 last_alloc = (u64)-1; 10296 int ret = 0; 10297 bool own_trans = true; 10298 u64 end = start + num_bytes - 1; 10299 10300 if (trans) 10301 own_trans = false; 10302 while (num_bytes > 0) { 10303 if (own_trans) { 10304 trans = btrfs_start_transaction(root, 3); 10305 if (IS_ERR(trans)) { 10306 ret = PTR_ERR(trans); 10307 break; 10308 } 10309 } 10310 10311 cur_bytes = min_t(u64, num_bytes, SZ_256M); 10312 cur_bytes = max(cur_bytes, min_size); 10313 /* 10314 * If we are severely fragmented we could end up with really 10315 * small allocations, so if the allocator is returning small 10316 * chunks lets make its job easier by only searching for those 10317 * sized chunks. 10318 */ 10319 cur_bytes = min(cur_bytes, last_alloc); 10320 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes, 10321 min_size, 0, *alloc_hint, &ins, 1, 0); 10322 if (ret) { 10323 if (own_trans) 10324 btrfs_end_transaction(trans); 10325 break; 10326 } 10327 btrfs_dec_block_group_reservations(fs_info, ins.objectid); 10328 10329 last_alloc = ins.offset; 10330 ret = insert_reserved_file_extent(trans, inode, 10331 cur_offset, ins.objectid, 10332 ins.offset, ins.offset, 10333 ins.offset, 0, 0, 0, 10334 BTRFS_FILE_EXTENT_PREALLOC); 10335 if (ret) { 10336 btrfs_free_reserved_extent(fs_info, ins.objectid, 10337 ins.offset, 0); 10338 btrfs_abort_transaction(trans, ret); 10339 if (own_trans) 10340 btrfs_end_transaction(trans); 10341 break; 10342 } 10343 10344 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset, 10345 cur_offset + ins.offset -1, 0); 10346 10347 em = alloc_extent_map(); 10348 if (!em) { 10349 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 10350 &BTRFS_I(inode)->runtime_flags); 10351 goto next; 10352 } 10353 10354 em->start = cur_offset; 10355 em->orig_start = cur_offset; 10356 em->len = ins.offset; 10357 em->block_start = ins.objectid; 10358 em->block_len = ins.offset; 10359 em->orig_block_len = ins.offset; 10360 em->ram_bytes = ins.offset; 10361 em->bdev = fs_info->fs_devices->latest_bdev; 10362 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 10363 em->generation = trans->transid; 10364 10365 while (1) { 10366 write_lock(&em_tree->lock); 10367 ret = add_extent_mapping(em_tree, em, 1); 10368 write_unlock(&em_tree->lock); 10369 if (ret != -EEXIST) 10370 break; 10371 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset, 10372 cur_offset + ins.offset - 1, 10373 0); 10374 } 10375 free_extent_map(em); 10376 next: 10377 num_bytes -= ins.offset; 10378 cur_offset += ins.offset; 10379 *alloc_hint = ins.objectid + ins.offset; 10380 10381 inode_inc_iversion(inode); 10382 inode->i_ctime = current_time(inode); 10383 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 10384 if (!(mode & FALLOC_FL_KEEP_SIZE) && 10385 (actual_len > inode->i_size) && 10386 (cur_offset > inode->i_size)) { 10387 if (cur_offset > actual_len) 10388 i_size = actual_len; 10389 else 10390 i_size = cur_offset; 10391 i_size_write(inode, i_size); 10392 btrfs_ordered_update_i_size(inode, i_size, NULL); 10393 } 10394 10395 ret = btrfs_update_inode(trans, root, inode); 10396 10397 if (ret) { 10398 btrfs_abort_transaction(trans, ret); 10399 if (own_trans) 10400 btrfs_end_transaction(trans); 10401 break; 10402 } 10403 10404 if (own_trans) 10405 btrfs_end_transaction(trans); 10406 } 10407 if (cur_offset < end) 10408 btrfs_free_reserved_data_space(inode, cur_offset, 10409 end - cur_offset + 1); 10410 return ret; 10411 } 10412 10413 int btrfs_prealloc_file_range(struct inode *inode, int mode, 10414 u64 start, u64 num_bytes, u64 min_size, 10415 loff_t actual_len, u64 *alloc_hint) 10416 { 10417 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 10418 min_size, actual_len, alloc_hint, 10419 NULL); 10420 } 10421 10422 int btrfs_prealloc_file_range_trans(struct inode *inode, 10423 struct btrfs_trans_handle *trans, int mode, 10424 u64 start, u64 num_bytes, u64 min_size, 10425 loff_t actual_len, u64 *alloc_hint) 10426 { 10427 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 10428 min_size, actual_len, alloc_hint, trans); 10429 } 10430 10431 static int btrfs_set_page_dirty(struct page *page) 10432 { 10433 return __set_page_dirty_nobuffers(page); 10434 } 10435 10436 static int btrfs_permission(struct inode *inode, int mask) 10437 { 10438 struct btrfs_root *root = BTRFS_I(inode)->root; 10439 umode_t mode = inode->i_mode; 10440 10441 if (mask & MAY_WRITE && 10442 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 10443 if (btrfs_root_readonly(root)) 10444 return -EROFS; 10445 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 10446 return -EACCES; 10447 } 10448 return generic_permission(inode, mask); 10449 } 10450 10451 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 10452 { 10453 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 10454 struct btrfs_trans_handle *trans; 10455 struct btrfs_root *root = BTRFS_I(dir)->root; 10456 struct inode *inode = NULL; 10457 u64 objectid; 10458 u64 index; 10459 int ret = 0; 10460 10461 /* 10462 * 5 units required for adding orphan entry 10463 */ 10464 trans = btrfs_start_transaction(root, 5); 10465 if (IS_ERR(trans)) 10466 return PTR_ERR(trans); 10467 10468 ret = btrfs_find_free_ino(root, &objectid); 10469 if (ret) 10470 goto out; 10471 10472 inode = btrfs_new_inode(trans, root, dir, NULL, 0, 10473 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index); 10474 if (IS_ERR(inode)) { 10475 ret = PTR_ERR(inode); 10476 inode = NULL; 10477 goto out; 10478 } 10479 10480 inode->i_fop = &btrfs_file_operations; 10481 inode->i_op = &btrfs_file_inode_operations; 10482 10483 inode->i_mapping->a_ops = &btrfs_aops; 10484 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 10485 10486 ret = btrfs_init_inode_security(trans, inode, dir, NULL); 10487 if (ret) 10488 goto out_inode; 10489 10490 ret = btrfs_update_inode(trans, root, inode); 10491 if (ret) 10492 goto out_inode; 10493 ret = btrfs_orphan_add(trans, BTRFS_I(inode)); 10494 if (ret) 10495 goto out_inode; 10496 10497 /* 10498 * We set number of links to 0 in btrfs_new_inode(), and here we set 10499 * it to 1 because d_tmpfile() will issue a warning if the count is 0, 10500 * through: 10501 * 10502 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink() 10503 */ 10504 set_nlink(inode, 1); 10505 unlock_new_inode(inode); 10506 d_tmpfile(dentry, inode); 10507 mark_inode_dirty(inode); 10508 10509 out: 10510 btrfs_end_transaction(trans); 10511 if (ret) 10512 iput(inode); 10513 btrfs_balance_delayed_items(fs_info); 10514 btrfs_btree_balance_dirty(fs_info); 10515 return ret; 10516 10517 out_inode: 10518 unlock_new_inode(inode); 10519 goto out; 10520 10521 } 10522 10523 __attribute__((const)) 10524 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror) 10525 { 10526 return -EAGAIN; 10527 } 10528 10529 static const struct inode_operations btrfs_dir_inode_operations = { 10530 .getattr = btrfs_getattr, 10531 .lookup = btrfs_lookup, 10532 .create = btrfs_create, 10533 .unlink = btrfs_unlink, 10534 .link = btrfs_link, 10535 .mkdir = btrfs_mkdir, 10536 .rmdir = btrfs_rmdir, 10537 .rename = btrfs_rename2, 10538 .symlink = btrfs_symlink, 10539 .setattr = btrfs_setattr, 10540 .mknod = btrfs_mknod, 10541 .listxattr = btrfs_listxattr, 10542 .permission = btrfs_permission, 10543 .get_acl = btrfs_get_acl, 10544 .set_acl = btrfs_set_acl, 10545 .update_time = btrfs_update_time, 10546 .tmpfile = btrfs_tmpfile, 10547 }; 10548 static const struct inode_operations btrfs_dir_ro_inode_operations = { 10549 .lookup = btrfs_lookup, 10550 .permission = btrfs_permission, 10551 .update_time = btrfs_update_time, 10552 }; 10553 10554 static const struct file_operations btrfs_dir_file_operations = { 10555 .llseek = generic_file_llseek, 10556 .read = generic_read_dir, 10557 .iterate_shared = btrfs_real_readdir, 10558 .unlocked_ioctl = btrfs_ioctl, 10559 #ifdef CONFIG_COMPAT 10560 .compat_ioctl = btrfs_compat_ioctl, 10561 #endif 10562 .release = btrfs_release_file, 10563 .fsync = btrfs_sync_file, 10564 }; 10565 10566 static const struct extent_io_ops btrfs_extent_io_ops = { 10567 /* mandatory callbacks */ 10568 .submit_bio_hook = btrfs_submit_bio_hook, 10569 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 10570 .merge_bio_hook = btrfs_merge_bio_hook, 10571 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook, 10572 10573 /* optional callbacks */ 10574 .fill_delalloc = run_delalloc_range, 10575 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 10576 .writepage_start_hook = btrfs_writepage_start_hook, 10577 .set_bit_hook = btrfs_set_bit_hook, 10578 .clear_bit_hook = btrfs_clear_bit_hook, 10579 .merge_extent_hook = btrfs_merge_extent_hook, 10580 .split_extent_hook = btrfs_split_extent_hook, 10581 }; 10582 10583 /* 10584 * btrfs doesn't support the bmap operation because swapfiles 10585 * use bmap to make a mapping of extents in the file. They assume 10586 * these extents won't change over the life of the file and they 10587 * use the bmap result to do IO directly to the drive. 10588 * 10589 * the btrfs bmap call would return logical addresses that aren't 10590 * suitable for IO and they also will change frequently as COW 10591 * operations happen. So, swapfile + btrfs == corruption. 10592 * 10593 * For now we're avoiding this by dropping bmap. 10594 */ 10595 static const struct address_space_operations btrfs_aops = { 10596 .readpage = btrfs_readpage, 10597 .writepage = btrfs_writepage, 10598 .writepages = btrfs_writepages, 10599 .readpages = btrfs_readpages, 10600 .direct_IO = btrfs_direct_IO, 10601 .invalidatepage = btrfs_invalidatepage, 10602 .releasepage = btrfs_releasepage, 10603 .set_page_dirty = btrfs_set_page_dirty, 10604 .error_remove_page = generic_error_remove_page, 10605 }; 10606 10607 static const struct address_space_operations btrfs_symlink_aops = { 10608 .readpage = btrfs_readpage, 10609 .writepage = btrfs_writepage, 10610 .invalidatepage = btrfs_invalidatepage, 10611 .releasepage = btrfs_releasepage, 10612 }; 10613 10614 static const struct inode_operations btrfs_file_inode_operations = { 10615 .getattr = btrfs_getattr, 10616 .setattr = btrfs_setattr, 10617 .listxattr = btrfs_listxattr, 10618 .permission = btrfs_permission, 10619 .fiemap = btrfs_fiemap, 10620 .get_acl = btrfs_get_acl, 10621 .set_acl = btrfs_set_acl, 10622 .update_time = btrfs_update_time, 10623 }; 10624 static const struct inode_operations btrfs_special_inode_operations = { 10625 .getattr = btrfs_getattr, 10626 .setattr = btrfs_setattr, 10627 .permission = btrfs_permission, 10628 .listxattr = btrfs_listxattr, 10629 .get_acl = btrfs_get_acl, 10630 .set_acl = btrfs_set_acl, 10631 .update_time = btrfs_update_time, 10632 }; 10633 static const struct inode_operations btrfs_symlink_inode_operations = { 10634 .get_link = page_get_link, 10635 .getattr = btrfs_getattr, 10636 .setattr = btrfs_setattr, 10637 .permission = btrfs_permission, 10638 .listxattr = btrfs_listxattr, 10639 .update_time = btrfs_update_time, 10640 }; 10641 10642 const struct dentry_operations btrfs_dentry_operations = { 10643 .d_delete = btrfs_dentry_delete, 10644 .d_release = btrfs_dentry_release, 10645 }; 10646