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/statfs.h> 34 #include <linux/compat.h> 35 #include <linux/bit_spinlock.h> 36 #include <linux/xattr.h> 37 #include <linux/posix_acl.h> 38 #include <linux/falloc.h> 39 #include <linux/slab.h> 40 #include <linux/ratelimit.h> 41 #include <linux/mount.h> 42 #include <linux/btrfs.h> 43 #include <linux/blkdev.h> 44 #include <linux/posix_acl_xattr.h> 45 #include <linux/uio.h> 46 #include "ctree.h" 47 #include "disk-io.h" 48 #include "transaction.h" 49 #include "btrfs_inode.h" 50 #include "print-tree.h" 51 #include "ordered-data.h" 52 #include "xattr.h" 53 #include "tree-log.h" 54 #include "volumes.h" 55 #include "compression.h" 56 #include "locking.h" 57 #include "free-space-cache.h" 58 #include "inode-map.h" 59 #include "backref.h" 60 #include "hash.h" 61 #include "props.h" 62 #include "qgroup.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 }; 75 76 static const struct inode_operations btrfs_dir_inode_operations; 77 static const struct inode_operations btrfs_symlink_inode_operations; 78 static const struct inode_operations btrfs_dir_ro_inode_operations; 79 static const struct inode_operations btrfs_special_inode_operations; 80 static const struct inode_operations btrfs_file_inode_operations; 81 static const struct address_space_operations btrfs_aops; 82 static const struct address_space_operations btrfs_symlink_aops; 83 static const struct file_operations btrfs_dir_file_operations; 84 static const struct extent_io_ops btrfs_extent_io_ops; 85 86 static struct kmem_cache *btrfs_inode_cachep; 87 struct kmem_cache *btrfs_trans_handle_cachep; 88 struct kmem_cache *btrfs_transaction_cachep; 89 struct kmem_cache *btrfs_path_cachep; 90 struct kmem_cache *btrfs_free_space_cachep; 91 92 #define S_SHIFT 12 93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { 94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, 95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, 96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, 97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, 98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, 99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, 100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, 101 }; 102 103 static int btrfs_setsize(struct inode *inode, struct iattr *attr); 104 static int btrfs_truncate(struct inode *inode); 105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); 106 static noinline int cow_file_range(struct inode *inode, 107 struct page *locked_page, 108 u64 start, u64 end, int *page_started, 109 unsigned long *nr_written, int unlock); 110 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 111 u64 len, u64 orig_start, 112 u64 block_start, u64 block_len, 113 u64 orig_block_len, u64 ram_bytes, 114 int type); 115 116 static int btrfs_dirty_inode(struct inode *inode); 117 118 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 119 void btrfs_test_inode_set_ops(struct inode *inode) 120 { 121 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 122 } 123 #endif 124 125 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, 126 struct inode *inode, struct inode *dir, 127 const struct qstr *qstr) 128 { 129 int err; 130 131 err = btrfs_init_acl(trans, inode, dir); 132 if (!err) 133 err = btrfs_xattr_security_init(trans, inode, dir, qstr); 134 return err; 135 } 136 137 /* 138 * this does all the hard work for inserting an inline extent into 139 * the btree. The caller should have done a btrfs_drop_extents so that 140 * no overlapping inline items exist in the btree 141 */ 142 static int insert_inline_extent(struct btrfs_trans_handle *trans, 143 struct btrfs_path *path, int extent_inserted, 144 struct btrfs_root *root, struct inode *inode, 145 u64 start, size_t size, size_t compressed_size, 146 int compress_type, 147 struct page **compressed_pages) 148 { 149 struct extent_buffer *leaf; 150 struct page *page = NULL; 151 char *kaddr; 152 unsigned long ptr; 153 struct btrfs_file_extent_item *ei; 154 int err = 0; 155 int ret; 156 size_t cur_size = size; 157 unsigned long offset; 158 159 if (compressed_size && compressed_pages) 160 cur_size = compressed_size; 161 162 inode_add_bytes(inode, size); 163 164 if (!extent_inserted) { 165 struct btrfs_key key; 166 size_t datasize; 167 168 key.objectid = btrfs_ino(inode); 169 key.offset = start; 170 key.type = BTRFS_EXTENT_DATA_KEY; 171 172 datasize = btrfs_file_extent_calc_inline_size(cur_size); 173 path->leave_spinning = 1; 174 ret = btrfs_insert_empty_item(trans, root, path, &key, 175 datasize); 176 if (ret) { 177 err = ret; 178 goto fail; 179 } 180 } 181 leaf = path->nodes[0]; 182 ei = btrfs_item_ptr(leaf, path->slots[0], 183 struct btrfs_file_extent_item); 184 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 185 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 186 btrfs_set_file_extent_encryption(leaf, ei, 0); 187 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 188 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 189 ptr = btrfs_file_extent_inline_start(ei); 190 191 if (compress_type != BTRFS_COMPRESS_NONE) { 192 struct page *cpage; 193 int i = 0; 194 while (compressed_size > 0) { 195 cpage = compressed_pages[i]; 196 cur_size = min_t(unsigned long, compressed_size, 197 PAGE_CACHE_SIZE); 198 199 kaddr = kmap_atomic(cpage); 200 write_extent_buffer(leaf, kaddr, ptr, cur_size); 201 kunmap_atomic(kaddr); 202 203 i++; 204 ptr += cur_size; 205 compressed_size -= cur_size; 206 } 207 btrfs_set_file_extent_compression(leaf, ei, 208 compress_type); 209 } else { 210 page = find_get_page(inode->i_mapping, 211 start >> PAGE_CACHE_SHIFT); 212 btrfs_set_file_extent_compression(leaf, ei, 0); 213 kaddr = kmap_atomic(page); 214 offset = start & (PAGE_CACHE_SIZE - 1); 215 write_extent_buffer(leaf, kaddr + offset, ptr, size); 216 kunmap_atomic(kaddr); 217 page_cache_release(page); 218 } 219 btrfs_mark_buffer_dirty(leaf); 220 btrfs_release_path(path); 221 222 /* 223 * we're an inline extent, so nobody can 224 * extend the file past i_size without locking 225 * a page we already have locked. 226 * 227 * We must do any isize and inode updates 228 * before we unlock the pages. Otherwise we 229 * could end up racing with unlink. 230 */ 231 BTRFS_I(inode)->disk_i_size = inode->i_size; 232 ret = btrfs_update_inode(trans, root, inode); 233 234 return ret; 235 fail: 236 return err; 237 } 238 239 240 /* 241 * conditionally insert an inline extent into the file. This 242 * does the checks required to make sure the data is small enough 243 * to fit as an inline extent. 244 */ 245 static noinline int cow_file_range_inline(struct btrfs_root *root, 246 struct inode *inode, u64 start, 247 u64 end, size_t compressed_size, 248 int compress_type, 249 struct page **compressed_pages) 250 { 251 struct btrfs_trans_handle *trans; 252 u64 isize = i_size_read(inode); 253 u64 actual_end = min(end + 1, isize); 254 u64 inline_len = actual_end - start; 255 u64 aligned_end = ALIGN(end, root->sectorsize); 256 u64 data_len = inline_len; 257 int ret; 258 struct btrfs_path *path; 259 int extent_inserted = 0; 260 u32 extent_item_size; 261 262 if (compressed_size) 263 data_len = compressed_size; 264 265 if (start > 0 || 266 actual_end > PAGE_CACHE_SIZE || 267 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) || 268 (!compressed_size && 269 (actual_end & (root->sectorsize - 1)) == 0) || 270 end + 1 < isize || 271 data_len > root->fs_info->max_inline) { 272 return 1; 273 } 274 275 path = btrfs_alloc_path(); 276 if (!path) 277 return -ENOMEM; 278 279 trans = btrfs_join_transaction(root); 280 if (IS_ERR(trans)) { 281 btrfs_free_path(path); 282 return PTR_ERR(trans); 283 } 284 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 285 286 if (compressed_size && compressed_pages) 287 extent_item_size = btrfs_file_extent_calc_inline_size( 288 compressed_size); 289 else 290 extent_item_size = btrfs_file_extent_calc_inline_size( 291 inline_len); 292 293 ret = __btrfs_drop_extents(trans, root, inode, path, 294 start, aligned_end, NULL, 295 1, 1, extent_item_size, &extent_inserted); 296 if (ret) { 297 btrfs_abort_transaction(trans, root, ret); 298 goto out; 299 } 300 301 if (isize > actual_end) 302 inline_len = min_t(u64, isize, actual_end); 303 ret = insert_inline_extent(trans, path, extent_inserted, 304 root, inode, start, 305 inline_len, compressed_size, 306 compress_type, compressed_pages); 307 if (ret && ret != -ENOSPC) { 308 btrfs_abort_transaction(trans, root, ret); 309 goto out; 310 } else if (ret == -ENOSPC) { 311 ret = 1; 312 goto out; 313 } 314 315 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 316 btrfs_delalloc_release_metadata(inode, end + 1 - start); 317 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); 318 out: 319 /* 320 * Don't forget to free the reserved space, as for inlined extent 321 * it won't count as data extent, free them directly here. 322 * And at reserve time, it's always aligned to page size, so 323 * just free one page here. 324 */ 325 btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE); 326 btrfs_free_path(path); 327 btrfs_end_transaction(trans, root); 328 return ret; 329 } 330 331 struct async_extent { 332 u64 start; 333 u64 ram_size; 334 u64 compressed_size; 335 struct page **pages; 336 unsigned long nr_pages; 337 int compress_type; 338 struct list_head list; 339 }; 340 341 struct async_cow { 342 struct inode *inode; 343 struct btrfs_root *root; 344 struct page *locked_page; 345 u64 start; 346 u64 end; 347 struct list_head extents; 348 struct btrfs_work work; 349 }; 350 351 static noinline int add_async_extent(struct async_cow *cow, 352 u64 start, u64 ram_size, 353 u64 compressed_size, 354 struct page **pages, 355 unsigned long nr_pages, 356 int compress_type) 357 { 358 struct async_extent *async_extent; 359 360 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 361 BUG_ON(!async_extent); /* -ENOMEM */ 362 async_extent->start = start; 363 async_extent->ram_size = ram_size; 364 async_extent->compressed_size = compressed_size; 365 async_extent->pages = pages; 366 async_extent->nr_pages = nr_pages; 367 async_extent->compress_type = compress_type; 368 list_add_tail(&async_extent->list, &cow->extents); 369 return 0; 370 } 371 372 static inline int inode_need_compress(struct inode *inode) 373 { 374 struct btrfs_root *root = BTRFS_I(inode)->root; 375 376 /* force compress */ 377 if (btrfs_test_opt(root, FORCE_COMPRESS)) 378 return 1; 379 /* bad compression ratios */ 380 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 381 return 0; 382 if (btrfs_test_opt(root, COMPRESS) || 383 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS || 384 BTRFS_I(inode)->force_compress) 385 return 1; 386 return 0; 387 } 388 389 /* 390 * we create compressed extents in two phases. The first 391 * phase compresses a range of pages that have already been 392 * locked (both pages and state bits are locked). 393 * 394 * This is done inside an ordered work queue, and the compression 395 * is spread across many cpus. The actual IO submission is step 396 * two, and the ordered work queue takes care of making sure that 397 * happens in the same order things were put onto the queue by 398 * writepages and friends. 399 * 400 * If this code finds it can't get good compression, it puts an 401 * entry onto the work queue to write the uncompressed bytes. This 402 * makes sure that both compressed inodes and uncompressed inodes 403 * are written in the same order that the flusher thread sent them 404 * down. 405 */ 406 static noinline void compress_file_range(struct inode *inode, 407 struct page *locked_page, 408 u64 start, u64 end, 409 struct async_cow *async_cow, 410 int *num_added) 411 { 412 struct btrfs_root *root = BTRFS_I(inode)->root; 413 u64 num_bytes; 414 u64 blocksize = root->sectorsize; 415 u64 actual_end; 416 u64 isize = i_size_read(inode); 417 int ret = 0; 418 struct page **pages = NULL; 419 unsigned long nr_pages; 420 unsigned long nr_pages_ret = 0; 421 unsigned long total_compressed = 0; 422 unsigned long total_in = 0; 423 unsigned long max_compressed = SZ_128K; 424 unsigned long max_uncompressed = SZ_128K; 425 int i; 426 int will_compress; 427 int compress_type = root->fs_info->compress_type; 428 int redirty = 0; 429 430 /* if this is a small write inside eof, kick off a defrag */ 431 if ((end - start + 1) < SZ_16K && 432 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 433 btrfs_add_inode_defrag(NULL, inode); 434 435 actual_end = min_t(u64, isize, end + 1); 436 again: 437 will_compress = 0; 438 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; 439 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_CACHE_SIZE); 440 441 /* 442 * we don't want to send crud past the end of i_size through 443 * compression, that's just a waste of CPU time. So, if the 444 * end of the file is before the start of our current 445 * requested range of bytes, we bail out to the uncompressed 446 * cleanup code that can deal with all of this. 447 * 448 * It isn't really the fastest way to fix things, but this is a 449 * very uncommon corner. 450 */ 451 if (actual_end <= start) 452 goto cleanup_and_bail_uncompressed; 453 454 total_compressed = actual_end - start; 455 456 /* 457 * skip compression for a small file range(<=blocksize) that 458 * isn't an inline extent, since it dosen't save disk space at all. 459 */ 460 if (total_compressed <= blocksize && 461 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 462 goto cleanup_and_bail_uncompressed; 463 464 /* we want to make sure that amount of ram required to uncompress 465 * an extent is reasonable, so we limit the total size in ram 466 * of a compressed extent to 128k. This is a crucial number 467 * because it also controls how easily we can spread reads across 468 * cpus for decompression. 469 * 470 * We also want to make sure the amount of IO required to do 471 * a random read is reasonably small, so we limit the size of 472 * a compressed extent to 128k. 473 */ 474 total_compressed = min(total_compressed, max_uncompressed); 475 num_bytes = ALIGN(end - start + 1, blocksize); 476 num_bytes = max(blocksize, num_bytes); 477 total_in = 0; 478 ret = 0; 479 480 /* 481 * we do compression for mount -o compress and when the 482 * inode has not been flagged as nocompress. This flag can 483 * change at any time if we discover bad compression ratios. 484 */ 485 if (inode_need_compress(inode)) { 486 WARN_ON(pages); 487 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); 488 if (!pages) { 489 /* just bail out to the uncompressed code */ 490 goto cont; 491 } 492 493 if (BTRFS_I(inode)->force_compress) 494 compress_type = BTRFS_I(inode)->force_compress; 495 496 /* 497 * we need to call clear_page_dirty_for_io on each 498 * page in the range. Otherwise applications with the file 499 * mmap'd can wander in and change the page contents while 500 * we are compressing them. 501 * 502 * If the compression fails for any reason, we set the pages 503 * dirty again later on. 504 */ 505 extent_range_clear_dirty_for_io(inode, start, end); 506 redirty = 1; 507 ret = btrfs_compress_pages(compress_type, 508 inode->i_mapping, start, 509 total_compressed, pages, 510 nr_pages, &nr_pages_ret, 511 &total_in, 512 &total_compressed, 513 max_compressed); 514 515 if (!ret) { 516 unsigned long offset = total_compressed & 517 (PAGE_CACHE_SIZE - 1); 518 struct page *page = pages[nr_pages_ret - 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_CACHE_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, 0, 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, NULL, 562 clear_flags, PAGE_UNLOCK | 563 PAGE_CLEAR_DIRTY | 564 PAGE_SET_WRITEBACK | 565 page_error_op | 566 PAGE_END_WRITEBACK); 567 goto free_pages_out; 568 } 569 } 570 571 if (will_compress) { 572 /* 573 * we aren't doing an inline extent round the compressed size 574 * up to a block size boundary so the allocator does sane 575 * things 576 */ 577 total_compressed = ALIGN(total_compressed, blocksize); 578 579 /* 580 * one last check to make sure the compression is really a 581 * win, compare the page count read with the blocks on disk 582 */ 583 total_in = ALIGN(total_in, PAGE_CACHE_SIZE); 584 if (total_compressed >= total_in) { 585 will_compress = 0; 586 } else { 587 num_bytes = total_in; 588 } 589 } 590 if (!will_compress && pages) { 591 /* 592 * the compression code ran but failed to make things smaller, 593 * free any pages it allocated and our page pointer array 594 */ 595 for (i = 0; i < nr_pages_ret; i++) { 596 WARN_ON(pages[i]->mapping); 597 page_cache_release(pages[i]); 598 } 599 kfree(pages); 600 pages = NULL; 601 total_compressed = 0; 602 nr_pages_ret = 0; 603 604 /* flag the file so we don't compress in the future */ 605 if (!btrfs_test_opt(root, FORCE_COMPRESS) && 606 !(BTRFS_I(inode)->force_compress)) { 607 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 608 } 609 } 610 if (will_compress) { 611 *num_added += 1; 612 613 /* the async work queues will take care of doing actual 614 * allocation on disk for these compressed pages, 615 * and will submit them to the elevator. 616 */ 617 add_async_extent(async_cow, start, num_bytes, 618 total_compressed, pages, nr_pages_ret, 619 compress_type); 620 621 if (start + num_bytes < end) { 622 start += num_bytes; 623 pages = NULL; 624 cond_resched(); 625 goto again; 626 } 627 } else { 628 cleanup_and_bail_uncompressed: 629 /* 630 * No compression, but we still need to write the pages in 631 * the file we've been given so far. redirty the locked 632 * page if it corresponds to our extent and set things up 633 * for the async work queue to run cow_file_range to do 634 * the normal delalloc dance 635 */ 636 if (page_offset(locked_page) >= start && 637 page_offset(locked_page) <= end) { 638 __set_page_dirty_nobuffers(locked_page); 639 /* unlocked later on in the async handlers */ 640 } 641 if (redirty) 642 extent_range_redirty_for_io(inode, start, end); 643 add_async_extent(async_cow, start, end - start + 1, 644 0, NULL, 0, BTRFS_COMPRESS_NONE); 645 *num_added += 1; 646 } 647 648 return; 649 650 free_pages_out: 651 for (i = 0; i < nr_pages_ret; i++) { 652 WARN_ON(pages[i]->mapping); 653 page_cache_release(pages[i]); 654 } 655 kfree(pages); 656 } 657 658 static void free_async_extent_pages(struct async_extent *async_extent) 659 { 660 int i; 661 662 if (!async_extent->pages) 663 return; 664 665 for (i = 0; i < async_extent->nr_pages; i++) { 666 WARN_ON(async_extent->pages[i]->mapping); 667 page_cache_release(async_extent->pages[i]); 668 } 669 kfree(async_extent->pages); 670 async_extent->nr_pages = 0; 671 async_extent->pages = NULL; 672 } 673 674 /* 675 * phase two of compressed writeback. This is the ordered portion 676 * of the code, which only gets called in the order the work was 677 * queued. We walk all the async extents created by compress_file_range 678 * and send them down to the disk. 679 */ 680 static noinline void submit_compressed_extents(struct inode *inode, 681 struct async_cow *async_cow) 682 { 683 struct async_extent *async_extent; 684 u64 alloc_hint = 0; 685 struct btrfs_key ins; 686 struct extent_map *em; 687 struct btrfs_root *root = BTRFS_I(inode)->root; 688 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 689 struct extent_io_tree *io_tree; 690 int ret = 0; 691 692 again: 693 while (!list_empty(&async_cow->extents)) { 694 async_extent = list_entry(async_cow->extents.next, 695 struct async_extent, list); 696 list_del(&async_extent->list); 697 698 io_tree = &BTRFS_I(inode)->io_tree; 699 700 retry: 701 /* did the compression code fall back to uncompressed IO? */ 702 if (!async_extent->pages) { 703 int page_started = 0; 704 unsigned long nr_written = 0; 705 706 lock_extent(io_tree, async_extent->start, 707 async_extent->start + 708 async_extent->ram_size - 1); 709 710 /* allocate blocks */ 711 ret = cow_file_range(inode, async_cow->locked_page, 712 async_extent->start, 713 async_extent->start + 714 async_extent->ram_size - 1, 715 &page_started, &nr_written, 0); 716 717 /* JDM XXX */ 718 719 /* 720 * if page_started, cow_file_range inserted an 721 * inline extent and took care of all the unlocking 722 * and IO for us. Otherwise, we need to submit 723 * all those pages down to the drive. 724 */ 725 if (!page_started && !ret) 726 extent_write_locked_range(io_tree, 727 inode, async_extent->start, 728 async_extent->start + 729 async_extent->ram_size - 1, 730 btrfs_get_extent, 731 WB_SYNC_ALL); 732 else if (ret) 733 unlock_page(async_cow->locked_page); 734 kfree(async_extent); 735 cond_resched(); 736 continue; 737 } 738 739 lock_extent(io_tree, async_extent->start, 740 async_extent->start + async_extent->ram_size - 1); 741 742 ret = btrfs_reserve_extent(root, 743 async_extent->compressed_size, 744 async_extent->compressed_size, 745 0, alloc_hint, &ins, 1, 1); 746 if (ret) { 747 free_async_extent_pages(async_extent); 748 749 if (ret == -ENOSPC) { 750 unlock_extent(io_tree, async_extent->start, 751 async_extent->start + 752 async_extent->ram_size - 1); 753 754 /* 755 * we need to redirty the pages if we decide to 756 * fallback to uncompressed IO, otherwise we 757 * will not submit these pages down to lower 758 * layers. 759 */ 760 extent_range_redirty_for_io(inode, 761 async_extent->start, 762 async_extent->start + 763 async_extent->ram_size - 1); 764 765 goto retry; 766 } 767 goto out_free; 768 } 769 /* 770 * here we're doing allocation and writeback of the 771 * compressed pages 772 */ 773 btrfs_drop_extent_cache(inode, async_extent->start, 774 async_extent->start + 775 async_extent->ram_size - 1, 0); 776 777 em = alloc_extent_map(); 778 if (!em) { 779 ret = -ENOMEM; 780 goto out_free_reserve; 781 } 782 em->start = async_extent->start; 783 em->len = async_extent->ram_size; 784 em->orig_start = em->start; 785 em->mod_start = em->start; 786 em->mod_len = em->len; 787 788 em->block_start = ins.objectid; 789 em->block_len = ins.offset; 790 em->orig_block_len = ins.offset; 791 em->ram_bytes = async_extent->ram_size; 792 em->bdev = root->fs_info->fs_devices->latest_bdev; 793 em->compress_type = async_extent->compress_type; 794 set_bit(EXTENT_FLAG_PINNED, &em->flags); 795 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 796 em->generation = -1; 797 798 while (1) { 799 write_lock(&em_tree->lock); 800 ret = add_extent_mapping(em_tree, em, 1); 801 write_unlock(&em_tree->lock); 802 if (ret != -EEXIST) { 803 free_extent_map(em); 804 break; 805 } 806 btrfs_drop_extent_cache(inode, async_extent->start, 807 async_extent->start + 808 async_extent->ram_size - 1, 0); 809 } 810 811 if (ret) 812 goto out_free_reserve; 813 814 ret = btrfs_add_ordered_extent_compress(inode, 815 async_extent->start, 816 ins.objectid, 817 async_extent->ram_size, 818 ins.offset, 819 BTRFS_ORDERED_COMPRESSED, 820 async_extent->compress_type); 821 if (ret) { 822 btrfs_drop_extent_cache(inode, async_extent->start, 823 async_extent->start + 824 async_extent->ram_size - 1, 0); 825 goto out_free_reserve; 826 } 827 828 /* 829 * clear dirty, set writeback and unlock the pages. 830 */ 831 extent_clear_unlock_delalloc(inode, async_extent->start, 832 async_extent->start + 833 async_extent->ram_size - 1, 834 NULL, EXTENT_LOCKED | EXTENT_DELALLOC, 835 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 836 PAGE_SET_WRITEBACK); 837 ret = btrfs_submit_compressed_write(inode, 838 async_extent->start, 839 async_extent->ram_size, 840 ins.objectid, 841 ins.offset, async_extent->pages, 842 async_extent->nr_pages); 843 if (ret) { 844 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; 845 struct page *p = async_extent->pages[0]; 846 const u64 start = async_extent->start; 847 const u64 end = start + async_extent->ram_size - 1; 848 849 p->mapping = inode->i_mapping; 850 tree->ops->writepage_end_io_hook(p, start, end, 851 NULL, 0); 852 p->mapping = NULL; 853 extent_clear_unlock_delalloc(inode, start, end, NULL, 0, 854 PAGE_END_WRITEBACK | 855 PAGE_SET_ERROR); 856 free_async_extent_pages(async_extent); 857 } 858 alloc_hint = ins.objectid + ins.offset; 859 kfree(async_extent); 860 cond_resched(); 861 } 862 return; 863 out_free_reserve: 864 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 865 out_free: 866 extent_clear_unlock_delalloc(inode, async_extent->start, 867 async_extent->start + 868 async_extent->ram_size - 1, 869 NULL, EXTENT_LOCKED | EXTENT_DELALLOC | 870 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, 871 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 872 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | 873 PAGE_SET_ERROR); 874 free_async_extent_pages(async_extent); 875 kfree(async_extent); 876 goto again; 877 } 878 879 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 880 u64 num_bytes) 881 { 882 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 883 struct extent_map *em; 884 u64 alloc_hint = 0; 885 886 read_lock(&em_tree->lock); 887 em = search_extent_mapping(em_tree, start, num_bytes); 888 if (em) { 889 /* 890 * if block start isn't an actual block number then find the 891 * first block in this inode and use that as a hint. If that 892 * block is also bogus then just don't worry about it. 893 */ 894 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 895 free_extent_map(em); 896 em = search_extent_mapping(em_tree, 0, 0); 897 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 898 alloc_hint = em->block_start; 899 if (em) 900 free_extent_map(em); 901 } else { 902 alloc_hint = em->block_start; 903 free_extent_map(em); 904 } 905 } 906 read_unlock(&em_tree->lock); 907 908 return alloc_hint; 909 } 910 911 /* 912 * when extent_io.c finds a delayed allocation range in the file, 913 * the call backs end up in this code. The basic idea is to 914 * allocate extents on disk for the range, and create ordered data structs 915 * in ram to track those extents. 916 * 917 * locked_page is the page that writepage had locked already. We use 918 * it to make sure we don't do extra locks or unlocks. 919 * 920 * *page_started is set to one if we unlock locked_page and do everything 921 * required to start IO on it. It may be clean and already done with 922 * IO when we return. 923 */ 924 static noinline int cow_file_range(struct inode *inode, 925 struct page *locked_page, 926 u64 start, u64 end, int *page_started, 927 unsigned long *nr_written, 928 int unlock) 929 { 930 struct btrfs_root *root = BTRFS_I(inode)->root; 931 u64 alloc_hint = 0; 932 u64 num_bytes; 933 unsigned long ram_size; 934 u64 disk_num_bytes; 935 u64 cur_alloc_size; 936 u64 blocksize = root->sectorsize; 937 struct btrfs_key ins; 938 struct extent_map *em; 939 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 940 int ret = 0; 941 942 if (btrfs_is_free_space_inode(inode)) { 943 WARN_ON_ONCE(1); 944 ret = -EINVAL; 945 goto out_unlock; 946 } 947 948 num_bytes = ALIGN(end - start + 1, blocksize); 949 num_bytes = max(blocksize, num_bytes); 950 disk_num_bytes = num_bytes; 951 952 /* if this is a small write inside eof, kick off defrag */ 953 if (num_bytes < SZ_64K && 954 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 955 btrfs_add_inode_defrag(NULL, inode); 956 957 if (start == 0) { 958 /* lets try to make an inline extent */ 959 ret = cow_file_range_inline(root, inode, start, end, 0, 0, 960 NULL); 961 if (ret == 0) { 962 extent_clear_unlock_delalloc(inode, start, end, NULL, 963 EXTENT_LOCKED | EXTENT_DELALLOC | 964 EXTENT_DEFRAG, PAGE_UNLOCK | 965 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | 966 PAGE_END_WRITEBACK); 967 968 *nr_written = *nr_written + 969 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; 970 *page_started = 1; 971 goto out; 972 } else if (ret < 0) { 973 goto out_unlock; 974 } 975 } 976 977 BUG_ON(disk_num_bytes > 978 btrfs_super_total_bytes(root->fs_info->super_copy)); 979 980 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 981 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); 982 983 while (disk_num_bytes > 0) { 984 unsigned long op; 985 986 cur_alloc_size = disk_num_bytes; 987 ret = btrfs_reserve_extent(root, cur_alloc_size, 988 root->sectorsize, 0, alloc_hint, 989 &ins, 1, 1); 990 if (ret < 0) 991 goto out_unlock; 992 993 em = alloc_extent_map(); 994 if (!em) { 995 ret = -ENOMEM; 996 goto out_reserve; 997 } 998 em->start = start; 999 em->orig_start = em->start; 1000 ram_size = ins.offset; 1001 em->len = ins.offset; 1002 em->mod_start = em->start; 1003 em->mod_len = em->len; 1004 1005 em->block_start = ins.objectid; 1006 em->block_len = ins.offset; 1007 em->orig_block_len = ins.offset; 1008 em->ram_bytes = ram_size; 1009 em->bdev = root->fs_info->fs_devices->latest_bdev; 1010 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1011 em->generation = -1; 1012 1013 while (1) { 1014 write_lock(&em_tree->lock); 1015 ret = add_extent_mapping(em_tree, em, 1); 1016 write_unlock(&em_tree->lock); 1017 if (ret != -EEXIST) { 1018 free_extent_map(em); 1019 break; 1020 } 1021 btrfs_drop_extent_cache(inode, start, 1022 start + ram_size - 1, 0); 1023 } 1024 if (ret) 1025 goto out_reserve; 1026 1027 cur_alloc_size = ins.offset; 1028 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 1029 ram_size, cur_alloc_size, 0); 1030 if (ret) 1031 goto out_drop_extent_cache; 1032 1033 if (root->root_key.objectid == 1034 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1035 ret = btrfs_reloc_clone_csums(inode, start, 1036 cur_alloc_size); 1037 if (ret) 1038 goto out_drop_extent_cache; 1039 } 1040 1041 if (disk_num_bytes < cur_alloc_size) 1042 break; 1043 1044 /* we're not doing compressed IO, don't unlock the first 1045 * page (which the caller expects to stay locked), don't 1046 * clear any dirty bits and don't set any writeback bits 1047 * 1048 * Do set the Private2 bit so we know this page was properly 1049 * setup for writepage 1050 */ 1051 op = unlock ? PAGE_UNLOCK : 0; 1052 op |= PAGE_SET_PRIVATE2; 1053 1054 extent_clear_unlock_delalloc(inode, start, 1055 start + ram_size - 1, locked_page, 1056 EXTENT_LOCKED | EXTENT_DELALLOC, 1057 op); 1058 disk_num_bytes -= cur_alloc_size; 1059 num_bytes -= cur_alloc_size; 1060 alloc_hint = ins.objectid + ins.offset; 1061 start += cur_alloc_size; 1062 } 1063 out: 1064 return ret; 1065 1066 out_drop_extent_cache: 1067 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); 1068 out_reserve: 1069 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 1070 out_unlock: 1071 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1072 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 1073 EXTENT_DELALLOC | EXTENT_DEFRAG, 1074 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 1075 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 1076 goto out; 1077 } 1078 1079 /* 1080 * work queue call back to started compression on a file and pages 1081 */ 1082 static noinline void async_cow_start(struct btrfs_work *work) 1083 { 1084 struct async_cow *async_cow; 1085 int num_added = 0; 1086 async_cow = container_of(work, struct async_cow, work); 1087 1088 compress_file_range(async_cow->inode, async_cow->locked_page, 1089 async_cow->start, async_cow->end, async_cow, 1090 &num_added); 1091 if (num_added == 0) { 1092 btrfs_add_delayed_iput(async_cow->inode); 1093 async_cow->inode = NULL; 1094 } 1095 } 1096 1097 /* 1098 * work queue call back to submit previously compressed pages 1099 */ 1100 static noinline void async_cow_submit(struct btrfs_work *work) 1101 { 1102 struct async_cow *async_cow; 1103 struct btrfs_root *root; 1104 unsigned long nr_pages; 1105 1106 async_cow = container_of(work, struct async_cow, work); 1107 1108 root = async_cow->root; 1109 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> 1110 PAGE_CACHE_SHIFT; 1111 1112 /* 1113 * atomic_sub_return implies a barrier for waitqueue_active 1114 */ 1115 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 1116 5 * SZ_1M && 1117 waitqueue_active(&root->fs_info->async_submit_wait)) 1118 wake_up(&root->fs_info->async_submit_wait); 1119 1120 if (async_cow->inode) 1121 submit_compressed_extents(async_cow->inode, async_cow); 1122 } 1123 1124 static noinline void async_cow_free(struct btrfs_work *work) 1125 { 1126 struct async_cow *async_cow; 1127 async_cow = container_of(work, struct async_cow, work); 1128 if (async_cow->inode) 1129 btrfs_add_delayed_iput(async_cow->inode); 1130 kfree(async_cow); 1131 } 1132 1133 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1134 u64 start, u64 end, int *page_started, 1135 unsigned long *nr_written) 1136 { 1137 struct async_cow *async_cow; 1138 struct btrfs_root *root = BTRFS_I(inode)->root; 1139 unsigned long nr_pages; 1140 u64 cur_end; 1141 int limit = 10 * SZ_1M; 1142 1143 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1144 1, 0, NULL, GFP_NOFS); 1145 while (start < end) { 1146 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1147 BUG_ON(!async_cow); /* -ENOMEM */ 1148 async_cow->inode = igrab(inode); 1149 async_cow->root = root; 1150 async_cow->locked_page = locked_page; 1151 async_cow->start = start; 1152 1153 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS && 1154 !btrfs_test_opt(root, FORCE_COMPRESS)) 1155 cur_end = end; 1156 else 1157 cur_end = min(end, start + SZ_512K - 1); 1158 1159 async_cow->end = cur_end; 1160 INIT_LIST_HEAD(&async_cow->extents); 1161 1162 btrfs_init_work(&async_cow->work, 1163 btrfs_delalloc_helper, 1164 async_cow_start, async_cow_submit, 1165 async_cow_free); 1166 1167 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> 1168 PAGE_CACHE_SHIFT; 1169 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); 1170 1171 btrfs_queue_work(root->fs_info->delalloc_workers, 1172 &async_cow->work); 1173 1174 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { 1175 wait_event(root->fs_info->async_submit_wait, 1176 (atomic_read(&root->fs_info->async_delalloc_pages) < 1177 limit)); 1178 } 1179 1180 while (atomic_read(&root->fs_info->async_submit_draining) && 1181 atomic_read(&root->fs_info->async_delalloc_pages)) { 1182 wait_event(root->fs_info->async_submit_wait, 1183 (atomic_read(&root->fs_info->async_delalloc_pages) == 1184 0)); 1185 } 1186 1187 *nr_written += nr_pages; 1188 start = cur_end + 1; 1189 } 1190 *page_started = 1; 1191 return 0; 1192 } 1193 1194 static noinline int csum_exist_in_range(struct btrfs_root *root, 1195 u64 bytenr, u64 num_bytes) 1196 { 1197 int ret; 1198 struct btrfs_ordered_sum *sums; 1199 LIST_HEAD(list); 1200 1201 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, 1202 bytenr + num_bytes - 1, &list, 0); 1203 if (ret == 0 && list_empty(&list)) 1204 return 0; 1205 1206 while (!list_empty(&list)) { 1207 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1208 list_del(&sums->list); 1209 kfree(sums); 1210 } 1211 return 1; 1212 } 1213 1214 /* 1215 * when nowcow writeback call back. This checks for snapshots or COW copies 1216 * of the extents that exist in the file, and COWs the file as required. 1217 * 1218 * If no cow copies or snapshots exist, we write directly to the existing 1219 * blocks on disk 1220 */ 1221 static noinline int run_delalloc_nocow(struct inode *inode, 1222 struct page *locked_page, 1223 u64 start, u64 end, int *page_started, int force, 1224 unsigned long *nr_written) 1225 { 1226 struct btrfs_root *root = BTRFS_I(inode)->root; 1227 struct btrfs_trans_handle *trans; 1228 struct extent_buffer *leaf; 1229 struct btrfs_path *path; 1230 struct btrfs_file_extent_item *fi; 1231 struct btrfs_key found_key; 1232 u64 cow_start; 1233 u64 cur_offset; 1234 u64 extent_end; 1235 u64 extent_offset; 1236 u64 disk_bytenr; 1237 u64 num_bytes; 1238 u64 disk_num_bytes; 1239 u64 ram_bytes; 1240 int extent_type; 1241 int ret, err; 1242 int type; 1243 int nocow; 1244 int check_prev = 1; 1245 bool nolock; 1246 u64 ino = btrfs_ino(inode); 1247 1248 path = btrfs_alloc_path(); 1249 if (!path) { 1250 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1251 EXTENT_LOCKED | EXTENT_DELALLOC | 1252 EXTENT_DO_ACCOUNTING | 1253 EXTENT_DEFRAG, PAGE_UNLOCK | 1254 PAGE_CLEAR_DIRTY | 1255 PAGE_SET_WRITEBACK | 1256 PAGE_END_WRITEBACK); 1257 return -ENOMEM; 1258 } 1259 1260 nolock = btrfs_is_free_space_inode(inode); 1261 1262 if (nolock) 1263 trans = btrfs_join_transaction_nolock(root); 1264 else 1265 trans = btrfs_join_transaction(root); 1266 1267 if (IS_ERR(trans)) { 1268 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1269 EXTENT_LOCKED | EXTENT_DELALLOC | 1270 EXTENT_DO_ACCOUNTING | 1271 EXTENT_DEFRAG, PAGE_UNLOCK | 1272 PAGE_CLEAR_DIRTY | 1273 PAGE_SET_WRITEBACK | 1274 PAGE_END_WRITEBACK); 1275 btrfs_free_path(path); 1276 return PTR_ERR(trans); 1277 } 1278 1279 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1280 1281 cow_start = (u64)-1; 1282 cur_offset = start; 1283 while (1) { 1284 ret = btrfs_lookup_file_extent(trans, root, path, ino, 1285 cur_offset, 0); 1286 if (ret < 0) 1287 goto error; 1288 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1289 leaf = path->nodes[0]; 1290 btrfs_item_key_to_cpu(leaf, &found_key, 1291 path->slots[0] - 1); 1292 if (found_key.objectid == ino && 1293 found_key.type == BTRFS_EXTENT_DATA_KEY) 1294 path->slots[0]--; 1295 } 1296 check_prev = 0; 1297 next_slot: 1298 leaf = path->nodes[0]; 1299 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1300 ret = btrfs_next_leaf(root, path); 1301 if (ret < 0) 1302 goto error; 1303 if (ret > 0) 1304 break; 1305 leaf = path->nodes[0]; 1306 } 1307 1308 nocow = 0; 1309 disk_bytenr = 0; 1310 num_bytes = 0; 1311 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1312 1313 if (found_key.objectid > ino) 1314 break; 1315 if (WARN_ON_ONCE(found_key.objectid < ino) || 1316 found_key.type < BTRFS_EXTENT_DATA_KEY) { 1317 path->slots[0]++; 1318 goto next_slot; 1319 } 1320 if (found_key.type > BTRFS_EXTENT_DATA_KEY || 1321 found_key.offset > end) 1322 break; 1323 1324 if (found_key.offset > cur_offset) { 1325 extent_end = found_key.offset; 1326 extent_type = 0; 1327 goto out_check; 1328 } 1329 1330 fi = btrfs_item_ptr(leaf, path->slots[0], 1331 struct btrfs_file_extent_item); 1332 extent_type = btrfs_file_extent_type(leaf, fi); 1333 1334 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1335 if (extent_type == BTRFS_FILE_EXTENT_REG || 1336 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1337 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1338 extent_offset = btrfs_file_extent_offset(leaf, fi); 1339 extent_end = found_key.offset + 1340 btrfs_file_extent_num_bytes(leaf, fi); 1341 disk_num_bytes = 1342 btrfs_file_extent_disk_num_bytes(leaf, fi); 1343 if (extent_end <= start) { 1344 path->slots[0]++; 1345 goto next_slot; 1346 } 1347 if (disk_bytenr == 0) 1348 goto out_check; 1349 if (btrfs_file_extent_compression(leaf, fi) || 1350 btrfs_file_extent_encryption(leaf, fi) || 1351 btrfs_file_extent_other_encoding(leaf, fi)) 1352 goto out_check; 1353 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1354 goto out_check; 1355 if (btrfs_extent_readonly(root, disk_bytenr)) 1356 goto out_check; 1357 if (btrfs_cross_ref_exist(trans, root, ino, 1358 found_key.offset - 1359 extent_offset, disk_bytenr)) 1360 goto out_check; 1361 disk_bytenr += extent_offset; 1362 disk_bytenr += cur_offset - found_key.offset; 1363 num_bytes = min(end + 1, extent_end) - cur_offset; 1364 /* 1365 * if there are pending snapshots for this root, 1366 * we fall into common COW way. 1367 */ 1368 if (!nolock) { 1369 err = btrfs_start_write_no_snapshoting(root); 1370 if (!err) 1371 goto out_check; 1372 } 1373 /* 1374 * force cow if csum exists in the range. 1375 * this ensure that csum for a given extent are 1376 * either valid or do not exist. 1377 */ 1378 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 1379 goto out_check; 1380 nocow = 1; 1381 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1382 extent_end = found_key.offset + 1383 btrfs_file_extent_inline_len(leaf, 1384 path->slots[0], fi); 1385 extent_end = ALIGN(extent_end, root->sectorsize); 1386 } else { 1387 BUG_ON(1); 1388 } 1389 out_check: 1390 if (extent_end <= start) { 1391 path->slots[0]++; 1392 if (!nolock && nocow) 1393 btrfs_end_write_no_snapshoting(root); 1394 goto next_slot; 1395 } 1396 if (!nocow) { 1397 if (cow_start == (u64)-1) 1398 cow_start = cur_offset; 1399 cur_offset = extent_end; 1400 if (cur_offset > end) 1401 break; 1402 path->slots[0]++; 1403 goto next_slot; 1404 } 1405 1406 btrfs_release_path(path); 1407 if (cow_start != (u64)-1) { 1408 ret = cow_file_range(inode, locked_page, 1409 cow_start, found_key.offset - 1, 1410 page_started, nr_written, 1); 1411 if (ret) { 1412 if (!nolock && nocow) 1413 btrfs_end_write_no_snapshoting(root); 1414 goto error; 1415 } 1416 cow_start = (u64)-1; 1417 } 1418 1419 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1420 struct extent_map *em; 1421 struct extent_map_tree *em_tree; 1422 em_tree = &BTRFS_I(inode)->extent_tree; 1423 em = alloc_extent_map(); 1424 BUG_ON(!em); /* -ENOMEM */ 1425 em->start = cur_offset; 1426 em->orig_start = found_key.offset - extent_offset; 1427 em->len = num_bytes; 1428 em->block_len = num_bytes; 1429 em->block_start = disk_bytenr; 1430 em->orig_block_len = disk_num_bytes; 1431 em->ram_bytes = ram_bytes; 1432 em->bdev = root->fs_info->fs_devices->latest_bdev; 1433 em->mod_start = em->start; 1434 em->mod_len = em->len; 1435 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1436 set_bit(EXTENT_FLAG_FILLING, &em->flags); 1437 em->generation = -1; 1438 while (1) { 1439 write_lock(&em_tree->lock); 1440 ret = add_extent_mapping(em_tree, em, 1); 1441 write_unlock(&em_tree->lock); 1442 if (ret != -EEXIST) { 1443 free_extent_map(em); 1444 break; 1445 } 1446 btrfs_drop_extent_cache(inode, em->start, 1447 em->start + em->len - 1, 0); 1448 } 1449 type = BTRFS_ORDERED_PREALLOC; 1450 } else { 1451 type = BTRFS_ORDERED_NOCOW; 1452 } 1453 1454 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1455 num_bytes, num_bytes, type); 1456 BUG_ON(ret); /* -ENOMEM */ 1457 1458 if (root->root_key.objectid == 1459 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1460 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1461 num_bytes); 1462 if (ret) { 1463 if (!nolock && nocow) 1464 btrfs_end_write_no_snapshoting(root); 1465 goto error; 1466 } 1467 } 1468 1469 extent_clear_unlock_delalloc(inode, cur_offset, 1470 cur_offset + num_bytes - 1, 1471 locked_page, EXTENT_LOCKED | 1472 EXTENT_DELALLOC, PAGE_UNLOCK | 1473 PAGE_SET_PRIVATE2); 1474 if (!nolock && nocow) 1475 btrfs_end_write_no_snapshoting(root); 1476 cur_offset = extent_end; 1477 if (cur_offset > end) 1478 break; 1479 } 1480 btrfs_release_path(path); 1481 1482 if (cur_offset <= end && cow_start == (u64)-1) { 1483 cow_start = cur_offset; 1484 cur_offset = end; 1485 } 1486 1487 if (cow_start != (u64)-1) { 1488 ret = cow_file_range(inode, locked_page, cow_start, end, 1489 page_started, nr_written, 1); 1490 if (ret) 1491 goto error; 1492 } 1493 1494 error: 1495 err = btrfs_end_transaction(trans, root); 1496 if (!ret) 1497 ret = err; 1498 1499 if (ret && cur_offset < end) 1500 extent_clear_unlock_delalloc(inode, cur_offset, end, 1501 locked_page, EXTENT_LOCKED | 1502 EXTENT_DELALLOC | EXTENT_DEFRAG | 1503 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | 1504 PAGE_CLEAR_DIRTY | 1505 PAGE_SET_WRITEBACK | 1506 PAGE_END_WRITEBACK); 1507 btrfs_free_path(path); 1508 return ret; 1509 } 1510 1511 static inline int need_force_cow(struct inode *inode, u64 start, u64 end) 1512 { 1513 1514 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 1515 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) 1516 return 0; 1517 1518 /* 1519 * @defrag_bytes is a hint value, no spinlock held here, 1520 * if is not zero, it means the file is defragging. 1521 * Force cow if given extent needs to be defragged. 1522 */ 1523 if (BTRFS_I(inode)->defrag_bytes && 1524 test_range_bit(&BTRFS_I(inode)->io_tree, start, end, 1525 EXTENT_DEFRAG, 0, NULL)) 1526 return 1; 1527 1528 return 0; 1529 } 1530 1531 /* 1532 * extent_io.c call back to do delayed allocation processing 1533 */ 1534 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1535 u64 start, u64 end, int *page_started, 1536 unsigned long *nr_written) 1537 { 1538 int ret; 1539 int force_cow = need_force_cow(inode, start, end); 1540 1541 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) { 1542 ret = run_delalloc_nocow(inode, locked_page, start, end, 1543 page_started, 1, nr_written); 1544 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) { 1545 ret = run_delalloc_nocow(inode, locked_page, start, end, 1546 page_started, 0, nr_written); 1547 } else if (!inode_need_compress(inode)) { 1548 ret = cow_file_range(inode, locked_page, start, end, 1549 page_started, nr_written, 1); 1550 } else { 1551 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1552 &BTRFS_I(inode)->runtime_flags); 1553 ret = cow_file_range_async(inode, locked_page, start, end, 1554 page_started, nr_written); 1555 } 1556 return ret; 1557 } 1558 1559 static void btrfs_split_extent_hook(struct inode *inode, 1560 struct extent_state *orig, u64 split) 1561 { 1562 u64 size; 1563 1564 /* not delalloc, ignore it */ 1565 if (!(orig->state & EXTENT_DELALLOC)) 1566 return; 1567 1568 size = orig->end - orig->start + 1; 1569 if (size > BTRFS_MAX_EXTENT_SIZE) { 1570 u64 num_extents; 1571 u64 new_size; 1572 1573 /* 1574 * See the explanation in btrfs_merge_extent_hook, the same 1575 * applies here, just in reverse. 1576 */ 1577 new_size = orig->end - split + 1; 1578 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, 1579 BTRFS_MAX_EXTENT_SIZE); 1580 new_size = split - orig->start; 1581 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, 1582 BTRFS_MAX_EXTENT_SIZE); 1583 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, 1584 BTRFS_MAX_EXTENT_SIZE) >= num_extents) 1585 return; 1586 } 1587 1588 spin_lock(&BTRFS_I(inode)->lock); 1589 BTRFS_I(inode)->outstanding_extents++; 1590 spin_unlock(&BTRFS_I(inode)->lock); 1591 } 1592 1593 /* 1594 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1595 * extents so we can keep track of new extents that are just merged onto old 1596 * extents, such as when we are doing sequential writes, so we can properly 1597 * account for the metadata space we'll need. 1598 */ 1599 static void btrfs_merge_extent_hook(struct inode *inode, 1600 struct extent_state *new, 1601 struct extent_state *other) 1602 { 1603 u64 new_size, old_size; 1604 u64 num_extents; 1605 1606 /* not delalloc, ignore it */ 1607 if (!(other->state & EXTENT_DELALLOC)) 1608 return; 1609 1610 if (new->start > other->start) 1611 new_size = new->end - other->start + 1; 1612 else 1613 new_size = other->end - new->start + 1; 1614 1615 /* we're not bigger than the max, unreserve the space and go */ 1616 if (new_size <= BTRFS_MAX_EXTENT_SIZE) { 1617 spin_lock(&BTRFS_I(inode)->lock); 1618 BTRFS_I(inode)->outstanding_extents--; 1619 spin_unlock(&BTRFS_I(inode)->lock); 1620 return; 1621 } 1622 1623 /* 1624 * We have to add up either side to figure out how many extents were 1625 * accounted for before we merged into one big extent. If the number of 1626 * extents we accounted for is <= the amount we need for the new range 1627 * then we can return, otherwise drop. Think of it like this 1628 * 1629 * [ 4k][MAX_SIZE] 1630 * 1631 * So we've grown the extent by a MAX_SIZE extent, this would mean we 1632 * need 2 outstanding extents, on one side we have 1 and the other side 1633 * we have 1 so they are == and we can return. But in this case 1634 * 1635 * [MAX_SIZE+4k][MAX_SIZE+4k] 1636 * 1637 * Each range on their own accounts for 2 extents, but merged together 1638 * they are only 3 extents worth of accounting, so we need to drop in 1639 * this case. 1640 */ 1641 old_size = other->end - other->start + 1; 1642 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, 1643 BTRFS_MAX_EXTENT_SIZE); 1644 old_size = new->end - new->start + 1; 1645 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, 1646 BTRFS_MAX_EXTENT_SIZE); 1647 1648 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, 1649 BTRFS_MAX_EXTENT_SIZE) >= num_extents) 1650 return; 1651 1652 spin_lock(&BTRFS_I(inode)->lock); 1653 BTRFS_I(inode)->outstanding_extents--; 1654 spin_unlock(&BTRFS_I(inode)->lock); 1655 } 1656 1657 static void btrfs_add_delalloc_inodes(struct btrfs_root *root, 1658 struct inode *inode) 1659 { 1660 spin_lock(&root->delalloc_lock); 1661 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1662 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1663 &root->delalloc_inodes); 1664 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1665 &BTRFS_I(inode)->runtime_flags); 1666 root->nr_delalloc_inodes++; 1667 if (root->nr_delalloc_inodes == 1) { 1668 spin_lock(&root->fs_info->delalloc_root_lock); 1669 BUG_ON(!list_empty(&root->delalloc_root)); 1670 list_add_tail(&root->delalloc_root, 1671 &root->fs_info->delalloc_roots); 1672 spin_unlock(&root->fs_info->delalloc_root_lock); 1673 } 1674 } 1675 spin_unlock(&root->delalloc_lock); 1676 } 1677 1678 static void btrfs_del_delalloc_inode(struct btrfs_root *root, 1679 struct inode *inode) 1680 { 1681 spin_lock(&root->delalloc_lock); 1682 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1683 list_del_init(&BTRFS_I(inode)->delalloc_inodes); 1684 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1685 &BTRFS_I(inode)->runtime_flags); 1686 root->nr_delalloc_inodes--; 1687 if (!root->nr_delalloc_inodes) { 1688 spin_lock(&root->fs_info->delalloc_root_lock); 1689 BUG_ON(list_empty(&root->delalloc_root)); 1690 list_del_init(&root->delalloc_root); 1691 spin_unlock(&root->fs_info->delalloc_root_lock); 1692 } 1693 } 1694 spin_unlock(&root->delalloc_lock); 1695 } 1696 1697 /* 1698 * extent_io.c set_bit_hook, used to track delayed allocation 1699 * bytes in this file, and to maintain the list of inodes that 1700 * have pending delalloc work to be done. 1701 */ 1702 static void btrfs_set_bit_hook(struct inode *inode, 1703 struct extent_state *state, unsigned *bits) 1704 { 1705 1706 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) 1707 WARN_ON(1); 1708 /* 1709 * set_bit and clear bit hooks normally require _irqsave/restore 1710 * but in this case, we are only testing for the DELALLOC 1711 * bit, which is only set or cleared with irqs on 1712 */ 1713 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1714 struct btrfs_root *root = BTRFS_I(inode)->root; 1715 u64 len = state->end + 1 - state->start; 1716 bool do_list = !btrfs_is_free_space_inode(inode); 1717 1718 if (*bits & EXTENT_FIRST_DELALLOC) { 1719 *bits &= ~EXTENT_FIRST_DELALLOC; 1720 } else { 1721 spin_lock(&BTRFS_I(inode)->lock); 1722 BTRFS_I(inode)->outstanding_extents++; 1723 spin_unlock(&BTRFS_I(inode)->lock); 1724 } 1725 1726 /* For sanity tests */ 1727 if (btrfs_test_is_dummy_root(root)) 1728 return; 1729 1730 __percpu_counter_add(&root->fs_info->delalloc_bytes, len, 1731 root->fs_info->delalloc_batch); 1732 spin_lock(&BTRFS_I(inode)->lock); 1733 BTRFS_I(inode)->delalloc_bytes += len; 1734 if (*bits & EXTENT_DEFRAG) 1735 BTRFS_I(inode)->defrag_bytes += len; 1736 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1737 &BTRFS_I(inode)->runtime_flags)) 1738 btrfs_add_delalloc_inodes(root, inode); 1739 spin_unlock(&BTRFS_I(inode)->lock); 1740 } 1741 } 1742 1743 /* 1744 * extent_io.c clear_bit_hook, see set_bit_hook for why 1745 */ 1746 static void btrfs_clear_bit_hook(struct inode *inode, 1747 struct extent_state *state, 1748 unsigned *bits) 1749 { 1750 u64 len = state->end + 1 - state->start; 1751 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1, 1752 BTRFS_MAX_EXTENT_SIZE); 1753 1754 spin_lock(&BTRFS_I(inode)->lock); 1755 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) 1756 BTRFS_I(inode)->defrag_bytes -= len; 1757 spin_unlock(&BTRFS_I(inode)->lock); 1758 1759 /* 1760 * set_bit and clear bit hooks normally require _irqsave/restore 1761 * but in this case, we are only testing for the DELALLOC 1762 * bit, which is only set or cleared with irqs on 1763 */ 1764 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1765 struct btrfs_root *root = BTRFS_I(inode)->root; 1766 bool do_list = !btrfs_is_free_space_inode(inode); 1767 1768 if (*bits & EXTENT_FIRST_DELALLOC) { 1769 *bits &= ~EXTENT_FIRST_DELALLOC; 1770 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1771 spin_lock(&BTRFS_I(inode)->lock); 1772 BTRFS_I(inode)->outstanding_extents -= num_extents; 1773 spin_unlock(&BTRFS_I(inode)->lock); 1774 } 1775 1776 /* 1777 * We don't reserve metadata space for space cache inodes so we 1778 * don't need to call dellalloc_release_metadata if there is an 1779 * error. 1780 */ 1781 if (*bits & EXTENT_DO_ACCOUNTING && 1782 root != root->fs_info->tree_root) 1783 btrfs_delalloc_release_metadata(inode, len); 1784 1785 /* For sanity tests. */ 1786 if (btrfs_test_is_dummy_root(root)) 1787 return; 1788 1789 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1790 && do_list && !(state->state & EXTENT_NORESERVE)) 1791 btrfs_free_reserved_data_space_noquota(inode, 1792 state->start, len); 1793 1794 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, 1795 root->fs_info->delalloc_batch); 1796 spin_lock(&BTRFS_I(inode)->lock); 1797 BTRFS_I(inode)->delalloc_bytes -= len; 1798 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && 1799 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1800 &BTRFS_I(inode)->runtime_flags)) 1801 btrfs_del_delalloc_inode(root, inode); 1802 spin_unlock(&BTRFS_I(inode)->lock); 1803 } 1804 } 1805 1806 /* 1807 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1808 * we don't create bios that span stripes or chunks 1809 */ 1810 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, 1811 size_t size, struct bio *bio, 1812 unsigned long bio_flags) 1813 { 1814 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 1815 u64 logical = (u64)bio->bi_iter.bi_sector << 9; 1816 u64 length = 0; 1817 u64 map_length; 1818 int ret; 1819 1820 if (bio_flags & EXTENT_BIO_COMPRESSED) 1821 return 0; 1822 1823 length = bio->bi_iter.bi_size; 1824 map_length = length; 1825 ret = btrfs_map_block(root->fs_info, rw, logical, 1826 &map_length, NULL, 0); 1827 /* Will always return 0 with map_multi == NULL */ 1828 BUG_ON(ret < 0); 1829 if (map_length < length + size) 1830 return 1; 1831 return 0; 1832 } 1833 1834 /* 1835 * in order to insert checksums into the metadata in large chunks, 1836 * we wait until bio submission time. All the pages in the bio are 1837 * checksummed and sums are attached onto the ordered extent record. 1838 * 1839 * At IO completion time the cums attached on the ordered extent record 1840 * are inserted into the btree 1841 */ 1842 static int __btrfs_submit_bio_start(struct inode *inode, int rw, 1843 struct bio *bio, int mirror_num, 1844 unsigned long bio_flags, 1845 u64 bio_offset) 1846 { 1847 struct btrfs_root *root = BTRFS_I(inode)->root; 1848 int ret = 0; 1849 1850 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1851 BUG_ON(ret); /* -ENOMEM */ 1852 return 0; 1853 } 1854 1855 /* 1856 * in order to insert checksums into the metadata in large chunks, 1857 * we wait until bio submission time. All the pages in the bio are 1858 * checksummed and sums are attached onto the ordered extent record. 1859 * 1860 * At IO completion time the cums attached on the ordered extent record 1861 * are inserted into the btree 1862 */ 1863 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 1864 int mirror_num, unsigned long bio_flags, 1865 u64 bio_offset) 1866 { 1867 struct btrfs_root *root = BTRFS_I(inode)->root; 1868 int ret; 1869 1870 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); 1871 if (ret) { 1872 bio->bi_error = ret; 1873 bio_endio(bio); 1874 } 1875 return ret; 1876 } 1877 1878 /* 1879 * extent_io.c submission hook. This does the right thing for csum calculation 1880 * on write, or reading the csums from the tree before a read 1881 */ 1882 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 1883 int mirror_num, unsigned long bio_flags, 1884 u64 bio_offset) 1885 { 1886 struct btrfs_root *root = BTRFS_I(inode)->root; 1887 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA; 1888 int ret = 0; 1889 int skip_sum; 1890 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1891 1892 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1893 1894 if (btrfs_is_free_space_inode(inode)) 1895 metadata = BTRFS_WQ_ENDIO_FREE_SPACE; 1896 1897 if (!(rw & REQ_WRITE)) { 1898 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); 1899 if (ret) 1900 goto out; 1901 1902 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1903 ret = btrfs_submit_compressed_read(inode, bio, 1904 mirror_num, 1905 bio_flags); 1906 goto out; 1907 } else if (!skip_sum) { 1908 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); 1909 if (ret) 1910 goto out; 1911 } 1912 goto mapit; 1913 } else if (async && !skip_sum) { 1914 /* csum items have already been cloned */ 1915 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1916 goto mapit; 1917 /* we're doing a write, do the async checksumming */ 1918 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 1919 inode, rw, bio, mirror_num, 1920 bio_flags, bio_offset, 1921 __btrfs_submit_bio_start, 1922 __btrfs_submit_bio_done); 1923 goto out; 1924 } else if (!skip_sum) { 1925 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1926 if (ret) 1927 goto out; 1928 } 1929 1930 mapit: 1931 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 1932 1933 out: 1934 if (ret < 0) { 1935 bio->bi_error = ret; 1936 bio_endio(bio); 1937 } 1938 return ret; 1939 } 1940 1941 /* 1942 * given a list of ordered sums record them in the inode. This happens 1943 * at IO completion time based on sums calculated at bio submission time. 1944 */ 1945 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1946 struct inode *inode, u64 file_offset, 1947 struct list_head *list) 1948 { 1949 struct btrfs_ordered_sum *sum; 1950 1951 list_for_each_entry(sum, list, list) { 1952 trans->adding_csums = 1; 1953 btrfs_csum_file_blocks(trans, 1954 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1955 trans->adding_csums = 0; 1956 } 1957 return 0; 1958 } 1959 1960 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1961 struct extent_state **cached_state) 1962 { 1963 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); 1964 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1965 cached_state, GFP_NOFS); 1966 } 1967 1968 /* see btrfs_writepage_start_hook for details on why this is required */ 1969 struct btrfs_writepage_fixup { 1970 struct page *page; 1971 struct btrfs_work work; 1972 }; 1973 1974 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1975 { 1976 struct btrfs_writepage_fixup *fixup; 1977 struct btrfs_ordered_extent *ordered; 1978 struct extent_state *cached_state = NULL; 1979 struct page *page; 1980 struct inode *inode; 1981 u64 page_start; 1982 u64 page_end; 1983 int ret; 1984 1985 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1986 page = fixup->page; 1987 again: 1988 lock_page(page); 1989 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1990 ClearPageChecked(page); 1991 goto out_page; 1992 } 1993 1994 inode = page->mapping->host; 1995 page_start = page_offset(page); 1996 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; 1997 1998 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 1999 &cached_state); 2000 2001 /* already ordered? We're done */ 2002 if (PagePrivate2(page)) 2003 goto out; 2004 2005 ordered = btrfs_lookup_ordered_extent(inode, page_start); 2006 if (ordered) { 2007 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 2008 page_end, &cached_state, GFP_NOFS); 2009 unlock_page(page); 2010 btrfs_start_ordered_extent(inode, ordered, 1); 2011 btrfs_put_ordered_extent(ordered); 2012 goto again; 2013 } 2014 2015 ret = btrfs_delalloc_reserve_space(inode, page_start, 2016 PAGE_CACHE_SIZE); 2017 if (ret) { 2018 mapping_set_error(page->mapping, ret); 2019 end_extent_writepage(page, ret, page_start, page_end); 2020 ClearPageChecked(page); 2021 goto out; 2022 } 2023 2024 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); 2025 ClearPageChecked(page); 2026 set_page_dirty(page); 2027 out: 2028 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 2029 &cached_state, GFP_NOFS); 2030 out_page: 2031 unlock_page(page); 2032 page_cache_release(page); 2033 kfree(fixup); 2034 } 2035 2036 /* 2037 * There are a few paths in the higher layers of the kernel that directly 2038 * set the page dirty bit without asking the filesystem if it is a 2039 * good idea. This causes problems because we want to make sure COW 2040 * properly happens and the data=ordered rules are followed. 2041 * 2042 * In our case any range that doesn't have the ORDERED bit set 2043 * hasn't been properly setup for IO. We kick off an async process 2044 * to fix it up. The async helper will wait for ordered extents, set 2045 * the delalloc bit and make it safe to write the page. 2046 */ 2047 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 2048 { 2049 struct inode *inode = page->mapping->host; 2050 struct btrfs_writepage_fixup *fixup; 2051 struct btrfs_root *root = BTRFS_I(inode)->root; 2052 2053 /* this page is properly in the ordered list */ 2054 if (TestClearPagePrivate2(page)) 2055 return 0; 2056 2057 if (PageChecked(page)) 2058 return -EAGAIN; 2059 2060 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 2061 if (!fixup) 2062 return -EAGAIN; 2063 2064 SetPageChecked(page); 2065 page_cache_get(page); 2066 btrfs_init_work(&fixup->work, btrfs_fixup_helper, 2067 btrfs_writepage_fixup_worker, NULL, NULL); 2068 fixup->page = page; 2069 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work); 2070 return -EBUSY; 2071 } 2072 2073 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 2074 struct inode *inode, u64 file_pos, 2075 u64 disk_bytenr, u64 disk_num_bytes, 2076 u64 num_bytes, u64 ram_bytes, 2077 u8 compression, u8 encryption, 2078 u16 other_encoding, int extent_type) 2079 { 2080 struct btrfs_root *root = BTRFS_I(inode)->root; 2081 struct btrfs_file_extent_item *fi; 2082 struct btrfs_path *path; 2083 struct extent_buffer *leaf; 2084 struct btrfs_key ins; 2085 int extent_inserted = 0; 2086 int ret; 2087 2088 path = btrfs_alloc_path(); 2089 if (!path) 2090 return -ENOMEM; 2091 2092 /* 2093 * we may be replacing one extent in the tree with another. 2094 * The new extent is pinned in the extent map, and we don't want 2095 * to drop it from the cache until it is completely in the btree. 2096 * 2097 * So, tell btrfs_drop_extents to leave this extent in the cache. 2098 * the caller is expected to unpin it and allow it to be merged 2099 * with the others. 2100 */ 2101 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, 2102 file_pos + num_bytes, NULL, 0, 2103 1, sizeof(*fi), &extent_inserted); 2104 if (ret) 2105 goto out; 2106 2107 if (!extent_inserted) { 2108 ins.objectid = btrfs_ino(inode); 2109 ins.offset = file_pos; 2110 ins.type = BTRFS_EXTENT_DATA_KEY; 2111 2112 path->leave_spinning = 1; 2113 ret = btrfs_insert_empty_item(trans, root, path, &ins, 2114 sizeof(*fi)); 2115 if (ret) 2116 goto out; 2117 } 2118 leaf = path->nodes[0]; 2119 fi = btrfs_item_ptr(leaf, path->slots[0], 2120 struct btrfs_file_extent_item); 2121 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 2122 btrfs_set_file_extent_type(leaf, fi, extent_type); 2123 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 2124 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 2125 btrfs_set_file_extent_offset(leaf, fi, 0); 2126 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 2127 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 2128 btrfs_set_file_extent_compression(leaf, fi, compression); 2129 btrfs_set_file_extent_encryption(leaf, fi, encryption); 2130 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 2131 2132 btrfs_mark_buffer_dirty(leaf); 2133 btrfs_release_path(path); 2134 2135 inode_add_bytes(inode, num_bytes); 2136 2137 ins.objectid = disk_bytenr; 2138 ins.offset = disk_num_bytes; 2139 ins.type = BTRFS_EXTENT_ITEM_KEY; 2140 ret = btrfs_alloc_reserved_file_extent(trans, root, 2141 root->root_key.objectid, 2142 btrfs_ino(inode), file_pos, 2143 ram_bytes, &ins); 2144 /* 2145 * Release the reserved range from inode dirty range map, as it is 2146 * already moved into delayed_ref_head 2147 */ 2148 btrfs_qgroup_release_data(inode, file_pos, ram_bytes); 2149 out: 2150 btrfs_free_path(path); 2151 2152 return ret; 2153 } 2154 2155 /* snapshot-aware defrag */ 2156 struct sa_defrag_extent_backref { 2157 struct rb_node node; 2158 struct old_sa_defrag_extent *old; 2159 u64 root_id; 2160 u64 inum; 2161 u64 file_pos; 2162 u64 extent_offset; 2163 u64 num_bytes; 2164 u64 generation; 2165 }; 2166 2167 struct old_sa_defrag_extent { 2168 struct list_head list; 2169 struct new_sa_defrag_extent *new; 2170 2171 u64 extent_offset; 2172 u64 bytenr; 2173 u64 offset; 2174 u64 len; 2175 int count; 2176 }; 2177 2178 struct new_sa_defrag_extent { 2179 struct rb_root root; 2180 struct list_head head; 2181 struct btrfs_path *path; 2182 struct inode *inode; 2183 u64 file_pos; 2184 u64 len; 2185 u64 bytenr; 2186 u64 disk_len; 2187 u8 compress_type; 2188 }; 2189 2190 static int backref_comp(struct sa_defrag_extent_backref *b1, 2191 struct sa_defrag_extent_backref *b2) 2192 { 2193 if (b1->root_id < b2->root_id) 2194 return -1; 2195 else if (b1->root_id > b2->root_id) 2196 return 1; 2197 2198 if (b1->inum < b2->inum) 2199 return -1; 2200 else if (b1->inum > b2->inum) 2201 return 1; 2202 2203 if (b1->file_pos < b2->file_pos) 2204 return -1; 2205 else if (b1->file_pos > b2->file_pos) 2206 return 1; 2207 2208 /* 2209 * [------------------------------] ===> (a range of space) 2210 * |<--->| |<---->| =============> (fs/file tree A) 2211 * |<---------------------------->| ===> (fs/file tree B) 2212 * 2213 * A range of space can refer to two file extents in one tree while 2214 * refer to only one file extent in another tree. 2215 * 2216 * So we may process a disk offset more than one time(two extents in A) 2217 * and locate at the same extent(one extent in B), then insert two same 2218 * backrefs(both refer to the extent in B). 2219 */ 2220 return 0; 2221 } 2222 2223 static void backref_insert(struct rb_root *root, 2224 struct sa_defrag_extent_backref *backref) 2225 { 2226 struct rb_node **p = &root->rb_node; 2227 struct rb_node *parent = NULL; 2228 struct sa_defrag_extent_backref *entry; 2229 int ret; 2230 2231 while (*p) { 2232 parent = *p; 2233 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2234 2235 ret = backref_comp(backref, entry); 2236 if (ret < 0) 2237 p = &(*p)->rb_left; 2238 else 2239 p = &(*p)->rb_right; 2240 } 2241 2242 rb_link_node(&backref->node, parent, p); 2243 rb_insert_color(&backref->node, root); 2244 } 2245 2246 /* 2247 * Note the backref might has changed, and in this case we just return 0. 2248 */ 2249 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2250 void *ctx) 2251 { 2252 struct btrfs_file_extent_item *extent; 2253 struct btrfs_fs_info *fs_info; 2254 struct old_sa_defrag_extent *old = ctx; 2255 struct new_sa_defrag_extent *new = old->new; 2256 struct btrfs_path *path = new->path; 2257 struct btrfs_key key; 2258 struct btrfs_root *root; 2259 struct sa_defrag_extent_backref *backref; 2260 struct extent_buffer *leaf; 2261 struct inode *inode = new->inode; 2262 int slot; 2263 int ret; 2264 u64 extent_offset; 2265 u64 num_bytes; 2266 2267 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2268 inum == btrfs_ino(inode)) 2269 return 0; 2270 2271 key.objectid = root_id; 2272 key.type = BTRFS_ROOT_ITEM_KEY; 2273 key.offset = (u64)-1; 2274 2275 fs_info = BTRFS_I(inode)->root->fs_info; 2276 root = btrfs_read_fs_root_no_name(fs_info, &key); 2277 if (IS_ERR(root)) { 2278 if (PTR_ERR(root) == -ENOENT) 2279 return 0; 2280 WARN_ON(1); 2281 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", 2282 inum, offset, root_id); 2283 return PTR_ERR(root); 2284 } 2285 2286 key.objectid = inum; 2287 key.type = BTRFS_EXTENT_DATA_KEY; 2288 if (offset > (u64)-1 << 32) 2289 key.offset = 0; 2290 else 2291 key.offset = offset; 2292 2293 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2294 if (WARN_ON(ret < 0)) 2295 return ret; 2296 ret = 0; 2297 2298 while (1) { 2299 cond_resched(); 2300 2301 leaf = path->nodes[0]; 2302 slot = path->slots[0]; 2303 2304 if (slot >= btrfs_header_nritems(leaf)) { 2305 ret = btrfs_next_leaf(root, path); 2306 if (ret < 0) { 2307 goto out; 2308 } else if (ret > 0) { 2309 ret = 0; 2310 goto out; 2311 } 2312 continue; 2313 } 2314 2315 path->slots[0]++; 2316 2317 btrfs_item_key_to_cpu(leaf, &key, slot); 2318 2319 if (key.objectid > inum) 2320 goto out; 2321 2322 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2323 continue; 2324 2325 extent = btrfs_item_ptr(leaf, slot, 2326 struct btrfs_file_extent_item); 2327 2328 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2329 continue; 2330 2331 /* 2332 * 'offset' refers to the exact key.offset, 2333 * NOT the 'offset' field in btrfs_extent_data_ref, ie. 2334 * (key.offset - extent_offset). 2335 */ 2336 if (key.offset != offset) 2337 continue; 2338 2339 extent_offset = btrfs_file_extent_offset(leaf, extent); 2340 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2341 2342 if (extent_offset >= old->extent_offset + old->offset + 2343 old->len || extent_offset + num_bytes <= 2344 old->extent_offset + old->offset) 2345 continue; 2346 break; 2347 } 2348 2349 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2350 if (!backref) { 2351 ret = -ENOENT; 2352 goto out; 2353 } 2354 2355 backref->root_id = root_id; 2356 backref->inum = inum; 2357 backref->file_pos = offset; 2358 backref->num_bytes = num_bytes; 2359 backref->extent_offset = extent_offset; 2360 backref->generation = btrfs_file_extent_generation(leaf, extent); 2361 backref->old = old; 2362 backref_insert(&new->root, backref); 2363 old->count++; 2364 out: 2365 btrfs_release_path(path); 2366 WARN_ON(ret); 2367 return ret; 2368 } 2369 2370 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2371 struct new_sa_defrag_extent *new) 2372 { 2373 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; 2374 struct old_sa_defrag_extent *old, *tmp; 2375 int ret; 2376 2377 new->path = path; 2378 2379 list_for_each_entry_safe(old, tmp, &new->head, list) { 2380 ret = iterate_inodes_from_logical(old->bytenr + 2381 old->extent_offset, fs_info, 2382 path, record_one_backref, 2383 old); 2384 if (ret < 0 && ret != -ENOENT) 2385 return false; 2386 2387 /* no backref to be processed for this extent */ 2388 if (!old->count) { 2389 list_del(&old->list); 2390 kfree(old); 2391 } 2392 } 2393 2394 if (list_empty(&new->head)) 2395 return false; 2396 2397 return true; 2398 } 2399 2400 static int relink_is_mergable(struct extent_buffer *leaf, 2401 struct btrfs_file_extent_item *fi, 2402 struct new_sa_defrag_extent *new) 2403 { 2404 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) 2405 return 0; 2406 2407 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2408 return 0; 2409 2410 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) 2411 return 0; 2412 2413 if (btrfs_file_extent_encryption(leaf, fi) || 2414 btrfs_file_extent_other_encoding(leaf, fi)) 2415 return 0; 2416 2417 return 1; 2418 } 2419 2420 /* 2421 * Note the backref might has changed, and in this case we just return 0. 2422 */ 2423 static noinline int relink_extent_backref(struct btrfs_path *path, 2424 struct sa_defrag_extent_backref *prev, 2425 struct sa_defrag_extent_backref *backref) 2426 { 2427 struct btrfs_file_extent_item *extent; 2428 struct btrfs_file_extent_item *item; 2429 struct btrfs_ordered_extent *ordered; 2430 struct btrfs_trans_handle *trans; 2431 struct btrfs_fs_info *fs_info; 2432 struct btrfs_root *root; 2433 struct btrfs_key key; 2434 struct extent_buffer *leaf; 2435 struct old_sa_defrag_extent *old = backref->old; 2436 struct new_sa_defrag_extent *new = old->new; 2437 struct inode *src_inode = new->inode; 2438 struct inode *inode; 2439 struct extent_state *cached = NULL; 2440 int ret = 0; 2441 u64 start; 2442 u64 len; 2443 u64 lock_start; 2444 u64 lock_end; 2445 bool merge = false; 2446 int index; 2447 2448 if (prev && prev->root_id == backref->root_id && 2449 prev->inum == backref->inum && 2450 prev->file_pos + prev->num_bytes == backref->file_pos) 2451 merge = true; 2452 2453 /* step 1: get root */ 2454 key.objectid = backref->root_id; 2455 key.type = BTRFS_ROOT_ITEM_KEY; 2456 key.offset = (u64)-1; 2457 2458 fs_info = BTRFS_I(src_inode)->root->fs_info; 2459 index = srcu_read_lock(&fs_info->subvol_srcu); 2460 2461 root = btrfs_read_fs_root_no_name(fs_info, &key); 2462 if (IS_ERR(root)) { 2463 srcu_read_unlock(&fs_info->subvol_srcu, index); 2464 if (PTR_ERR(root) == -ENOENT) 2465 return 0; 2466 return PTR_ERR(root); 2467 } 2468 2469 if (btrfs_root_readonly(root)) { 2470 srcu_read_unlock(&fs_info->subvol_srcu, index); 2471 return 0; 2472 } 2473 2474 /* step 2: get inode */ 2475 key.objectid = backref->inum; 2476 key.type = BTRFS_INODE_ITEM_KEY; 2477 key.offset = 0; 2478 2479 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2480 if (IS_ERR(inode)) { 2481 srcu_read_unlock(&fs_info->subvol_srcu, index); 2482 return 0; 2483 } 2484 2485 srcu_read_unlock(&fs_info->subvol_srcu, index); 2486 2487 /* step 3: relink backref */ 2488 lock_start = backref->file_pos; 2489 lock_end = backref->file_pos + backref->num_bytes - 1; 2490 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2491 &cached); 2492 2493 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2494 if (ordered) { 2495 btrfs_put_ordered_extent(ordered); 2496 goto out_unlock; 2497 } 2498 2499 trans = btrfs_join_transaction(root); 2500 if (IS_ERR(trans)) { 2501 ret = PTR_ERR(trans); 2502 goto out_unlock; 2503 } 2504 2505 key.objectid = backref->inum; 2506 key.type = BTRFS_EXTENT_DATA_KEY; 2507 key.offset = backref->file_pos; 2508 2509 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2510 if (ret < 0) { 2511 goto out_free_path; 2512 } else if (ret > 0) { 2513 ret = 0; 2514 goto out_free_path; 2515 } 2516 2517 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2518 struct btrfs_file_extent_item); 2519 2520 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2521 backref->generation) 2522 goto out_free_path; 2523 2524 btrfs_release_path(path); 2525 2526 start = backref->file_pos; 2527 if (backref->extent_offset < old->extent_offset + old->offset) 2528 start += old->extent_offset + old->offset - 2529 backref->extent_offset; 2530 2531 len = min(backref->extent_offset + backref->num_bytes, 2532 old->extent_offset + old->offset + old->len); 2533 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2534 2535 ret = btrfs_drop_extents(trans, root, inode, start, 2536 start + len, 1); 2537 if (ret) 2538 goto out_free_path; 2539 again: 2540 key.objectid = btrfs_ino(inode); 2541 key.type = BTRFS_EXTENT_DATA_KEY; 2542 key.offset = start; 2543 2544 path->leave_spinning = 1; 2545 if (merge) { 2546 struct btrfs_file_extent_item *fi; 2547 u64 extent_len; 2548 struct btrfs_key found_key; 2549 2550 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 2551 if (ret < 0) 2552 goto out_free_path; 2553 2554 path->slots[0]--; 2555 leaf = path->nodes[0]; 2556 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2557 2558 fi = btrfs_item_ptr(leaf, path->slots[0], 2559 struct btrfs_file_extent_item); 2560 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2561 2562 if (extent_len + found_key.offset == start && 2563 relink_is_mergable(leaf, fi, new)) { 2564 btrfs_set_file_extent_num_bytes(leaf, fi, 2565 extent_len + len); 2566 btrfs_mark_buffer_dirty(leaf); 2567 inode_add_bytes(inode, len); 2568 2569 ret = 1; 2570 goto out_free_path; 2571 } else { 2572 merge = false; 2573 btrfs_release_path(path); 2574 goto again; 2575 } 2576 } 2577 2578 ret = btrfs_insert_empty_item(trans, root, path, &key, 2579 sizeof(*extent)); 2580 if (ret) { 2581 btrfs_abort_transaction(trans, root, ret); 2582 goto out_free_path; 2583 } 2584 2585 leaf = path->nodes[0]; 2586 item = btrfs_item_ptr(leaf, path->slots[0], 2587 struct btrfs_file_extent_item); 2588 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2589 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2590 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2591 btrfs_set_file_extent_num_bytes(leaf, item, len); 2592 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2593 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2594 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2595 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2596 btrfs_set_file_extent_encryption(leaf, item, 0); 2597 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2598 2599 btrfs_mark_buffer_dirty(leaf); 2600 inode_add_bytes(inode, len); 2601 btrfs_release_path(path); 2602 2603 ret = btrfs_inc_extent_ref(trans, root, new->bytenr, 2604 new->disk_len, 0, 2605 backref->root_id, backref->inum, 2606 new->file_pos); /* start - extent_offset */ 2607 if (ret) { 2608 btrfs_abort_transaction(trans, root, ret); 2609 goto out_free_path; 2610 } 2611 2612 ret = 1; 2613 out_free_path: 2614 btrfs_release_path(path); 2615 path->leave_spinning = 0; 2616 btrfs_end_transaction(trans, root); 2617 out_unlock: 2618 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2619 &cached, GFP_NOFS); 2620 iput(inode); 2621 return ret; 2622 } 2623 2624 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) 2625 { 2626 struct old_sa_defrag_extent *old, *tmp; 2627 2628 if (!new) 2629 return; 2630 2631 list_for_each_entry_safe(old, tmp, &new->head, list) { 2632 kfree(old); 2633 } 2634 kfree(new); 2635 } 2636 2637 static void relink_file_extents(struct new_sa_defrag_extent *new) 2638 { 2639 struct btrfs_path *path; 2640 struct sa_defrag_extent_backref *backref; 2641 struct sa_defrag_extent_backref *prev = NULL; 2642 struct inode *inode; 2643 struct btrfs_root *root; 2644 struct rb_node *node; 2645 int ret; 2646 2647 inode = new->inode; 2648 root = BTRFS_I(inode)->root; 2649 2650 path = btrfs_alloc_path(); 2651 if (!path) 2652 return; 2653 2654 if (!record_extent_backrefs(path, new)) { 2655 btrfs_free_path(path); 2656 goto out; 2657 } 2658 btrfs_release_path(path); 2659 2660 while (1) { 2661 node = rb_first(&new->root); 2662 if (!node) 2663 break; 2664 rb_erase(node, &new->root); 2665 2666 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2667 2668 ret = relink_extent_backref(path, prev, backref); 2669 WARN_ON(ret < 0); 2670 2671 kfree(prev); 2672 2673 if (ret == 1) 2674 prev = backref; 2675 else 2676 prev = NULL; 2677 cond_resched(); 2678 } 2679 kfree(prev); 2680 2681 btrfs_free_path(path); 2682 out: 2683 free_sa_defrag_extent(new); 2684 2685 atomic_dec(&root->fs_info->defrag_running); 2686 wake_up(&root->fs_info->transaction_wait); 2687 } 2688 2689 static struct new_sa_defrag_extent * 2690 record_old_file_extents(struct inode *inode, 2691 struct btrfs_ordered_extent *ordered) 2692 { 2693 struct btrfs_root *root = BTRFS_I(inode)->root; 2694 struct btrfs_path *path; 2695 struct btrfs_key key; 2696 struct old_sa_defrag_extent *old; 2697 struct new_sa_defrag_extent *new; 2698 int ret; 2699 2700 new = kmalloc(sizeof(*new), GFP_NOFS); 2701 if (!new) 2702 return NULL; 2703 2704 new->inode = inode; 2705 new->file_pos = ordered->file_offset; 2706 new->len = ordered->len; 2707 new->bytenr = ordered->start; 2708 new->disk_len = ordered->disk_len; 2709 new->compress_type = ordered->compress_type; 2710 new->root = RB_ROOT; 2711 INIT_LIST_HEAD(&new->head); 2712 2713 path = btrfs_alloc_path(); 2714 if (!path) 2715 goto out_kfree; 2716 2717 key.objectid = btrfs_ino(inode); 2718 key.type = BTRFS_EXTENT_DATA_KEY; 2719 key.offset = new->file_pos; 2720 2721 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2722 if (ret < 0) 2723 goto out_free_path; 2724 if (ret > 0 && path->slots[0] > 0) 2725 path->slots[0]--; 2726 2727 /* find out all the old extents for the file range */ 2728 while (1) { 2729 struct btrfs_file_extent_item *extent; 2730 struct extent_buffer *l; 2731 int slot; 2732 u64 num_bytes; 2733 u64 offset; 2734 u64 end; 2735 u64 disk_bytenr; 2736 u64 extent_offset; 2737 2738 l = path->nodes[0]; 2739 slot = path->slots[0]; 2740 2741 if (slot >= btrfs_header_nritems(l)) { 2742 ret = btrfs_next_leaf(root, path); 2743 if (ret < 0) 2744 goto out_free_path; 2745 else if (ret > 0) 2746 break; 2747 continue; 2748 } 2749 2750 btrfs_item_key_to_cpu(l, &key, slot); 2751 2752 if (key.objectid != btrfs_ino(inode)) 2753 break; 2754 if (key.type != BTRFS_EXTENT_DATA_KEY) 2755 break; 2756 if (key.offset >= new->file_pos + new->len) 2757 break; 2758 2759 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2760 2761 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2762 if (key.offset + num_bytes < new->file_pos) 2763 goto next; 2764 2765 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2766 if (!disk_bytenr) 2767 goto next; 2768 2769 extent_offset = btrfs_file_extent_offset(l, extent); 2770 2771 old = kmalloc(sizeof(*old), GFP_NOFS); 2772 if (!old) 2773 goto out_free_path; 2774 2775 offset = max(new->file_pos, key.offset); 2776 end = min(new->file_pos + new->len, key.offset + num_bytes); 2777 2778 old->bytenr = disk_bytenr; 2779 old->extent_offset = extent_offset; 2780 old->offset = offset - key.offset; 2781 old->len = end - offset; 2782 old->new = new; 2783 old->count = 0; 2784 list_add_tail(&old->list, &new->head); 2785 next: 2786 path->slots[0]++; 2787 cond_resched(); 2788 } 2789 2790 btrfs_free_path(path); 2791 atomic_inc(&root->fs_info->defrag_running); 2792 2793 return new; 2794 2795 out_free_path: 2796 btrfs_free_path(path); 2797 out_kfree: 2798 free_sa_defrag_extent(new); 2799 return NULL; 2800 } 2801 2802 static void btrfs_release_delalloc_bytes(struct btrfs_root *root, 2803 u64 start, u64 len) 2804 { 2805 struct btrfs_block_group_cache *cache; 2806 2807 cache = btrfs_lookup_block_group(root->fs_info, start); 2808 ASSERT(cache); 2809 2810 spin_lock(&cache->lock); 2811 cache->delalloc_bytes -= len; 2812 spin_unlock(&cache->lock); 2813 2814 btrfs_put_block_group(cache); 2815 } 2816 2817 /* as ordered data IO finishes, this gets called so we can finish 2818 * an ordered extent if the range of bytes in the file it covers are 2819 * fully written. 2820 */ 2821 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2822 { 2823 struct inode *inode = ordered_extent->inode; 2824 struct btrfs_root *root = BTRFS_I(inode)->root; 2825 struct btrfs_trans_handle *trans = NULL; 2826 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2827 struct extent_state *cached_state = NULL; 2828 struct new_sa_defrag_extent *new = NULL; 2829 int compress_type = 0; 2830 int ret = 0; 2831 u64 logical_len = ordered_extent->len; 2832 bool nolock; 2833 bool truncated = false; 2834 2835 nolock = btrfs_is_free_space_inode(inode); 2836 2837 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2838 ret = -EIO; 2839 goto out; 2840 } 2841 2842 btrfs_free_io_failure_record(inode, ordered_extent->file_offset, 2843 ordered_extent->file_offset + 2844 ordered_extent->len - 1); 2845 2846 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { 2847 truncated = true; 2848 logical_len = ordered_extent->truncated_len; 2849 /* Truncated the entire extent, don't bother adding */ 2850 if (!logical_len) 2851 goto out; 2852 } 2853 2854 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2855 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2856 2857 /* 2858 * For mwrite(mmap + memset to write) case, we still reserve 2859 * space for NOCOW range. 2860 * As NOCOW won't cause a new delayed ref, just free the space 2861 */ 2862 btrfs_qgroup_free_data(inode, ordered_extent->file_offset, 2863 ordered_extent->len); 2864 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2865 if (nolock) 2866 trans = btrfs_join_transaction_nolock(root); 2867 else 2868 trans = btrfs_join_transaction(root); 2869 if (IS_ERR(trans)) { 2870 ret = PTR_ERR(trans); 2871 trans = NULL; 2872 goto out; 2873 } 2874 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2875 ret = btrfs_update_inode_fallback(trans, root, inode); 2876 if (ret) /* -ENOMEM or corruption */ 2877 btrfs_abort_transaction(trans, root, ret); 2878 goto out; 2879 } 2880 2881 lock_extent_bits(io_tree, ordered_extent->file_offset, 2882 ordered_extent->file_offset + ordered_extent->len - 1, 2883 &cached_state); 2884 2885 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2886 ordered_extent->file_offset + ordered_extent->len - 1, 2887 EXTENT_DEFRAG, 1, cached_state); 2888 if (ret) { 2889 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2890 if (0 && last_snapshot >= BTRFS_I(inode)->generation) 2891 /* the inode is shared */ 2892 new = record_old_file_extents(inode, ordered_extent); 2893 2894 clear_extent_bit(io_tree, ordered_extent->file_offset, 2895 ordered_extent->file_offset + ordered_extent->len - 1, 2896 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2897 } 2898 2899 if (nolock) 2900 trans = btrfs_join_transaction_nolock(root); 2901 else 2902 trans = btrfs_join_transaction(root); 2903 if (IS_ERR(trans)) { 2904 ret = PTR_ERR(trans); 2905 trans = NULL; 2906 goto out_unlock; 2907 } 2908 2909 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2910 2911 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2912 compress_type = ordered_extent->compress_type; 2913 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2914 BUG_ON(compress_type); 2915 ret = btrfs_mark_extent_written(trans, inode, 2916 ordered_extent->file_offset, 2917 ordered_extent->file_offset + 2918 logical_len); 2919 } else { 2920 BUG_ON(root == root->fs_info->tree_root); 2921 ret = insert_reserved_file_extent(trans, inode, 2922 ordered_extent->file_offset, 2923 ordered_extent->start, 2924 ordered_extent->disk_len, 2925 logical_len, logical_len, 2926 compress_type, 0, 0, 2927 BTRFS_FILE_EXTENT_REG); 2928 if (!ret) 2929 btrfs_release_delalloc_bytes(root, 2930 ordered_extent->start, 2931 ordered_extent->disk_len); 2932 } 2933 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2934 ordered_extent->file_offset, ordered_extent->len, 2935 trans->transid); 2936 if (ret < 0) { 2937 btrfs_abort_transaction(trans, root, ret); 2938 goto out_unlock; 2939 } 2940 2941 add_pending_csums(trans, inode, ordered_extent->file_offset, 2942 &ordered_extent->list); 2943 2944 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2945 ret = btrfs_update_inode_fallback(trans, root, inode); 2946 if (ret) { /* -ENOMEM or corruption */ 2947 btrfs_abort_transaction(trans, root, ret); 2948 goto out_unlock; 2949 } 2950 ret = 0; 2951 out_unlock: 2952 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2953 ordered_extent->file_offset + 2954 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2955 out: 2956 if (root != root->fs_info->tree_root) 2957 btrfs_delalloc_release_metadata(inode, ordered_extent->len); 2958 if (trans) 2959 btrfs_end_transaction(trans, root); 2960 2961 if (ret || truncated) { 2962 u64 start, end; 2963 2964 if (truncated) 2965 start = ordered_extent->file_offset + logical_len; 2966 else 2967 start = ordered_extent->file_offset; 2968 end = ordered_extent->file_offset + ordered_extent->len - 1; 2969 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); 2970 2971 /* Drop the cache for the part of the extent we didn't write. */ 2972 btrfs_drop_extent_cache(inode, start, end, 0); 2973 2974 /* 2975 * If the ordered extent had an IOERR or something else went 2976 * wrong we need to return the space for this ordered extent 2977 * back to the allocator. We only free the extent in the 2978 * truncated case if we didn't write out the extent at all. 2979 */ 2980 if ((ret || !logical_len) && 2981 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2982 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2983 btrfs_free_reserved_extent(root, ordered_extent->start, 2984 ordered_extent->disk_len, 1); 2985 } 2986 2987 2988 /* 2989 * This needs to be done to make sure anybody waiting knows we are done 2990 * updating everything for this ordered extent. 2991 */ 2992 btrfs_remove_ordered_extent(inode, ordered_extent); 2993 2994 /* for snapshot-aware defrag */ 2995 if (new) { 2996 if (ret) { 2997 free_sa_defrag_extent(new); 2998 atomic_dec(&root->fs_info->defrag_running); 2999 } else { 3000 relink_file_extents(new); 3001 } 3002 } 3003 3004 /* once for us */ 3005 btrfs_put_ordered_extent(ordered_extent); 3006 /* once for the tree */ 3007 btrfs_put_ordered_extent(ordered_extent); 3008 3009 return ret; 3010 } 3011 3012 static void finish_ordered_fn(struct btrfs_work *work) 3013 { 3014 struct btrfs_ordered_extent *ordered_extent; 3015 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 3016 btrfs_finish_ordered_io(ordered_extent); 3017 } 3018 3019 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 3020 struct extent_state *state, int uptodate) 3021 { 3022 struct inode *inode = page->mapping->host; 3023 struct btrfs_root *root = BTRFS_I(inode)->root; 3024 struct btrfs_ordered_extent *ordered_extent = NULL; 3025 struct btrfs_workqueue *wq; 3026 btrfs_work_func_t func; 3027 3028 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 3029 3030 ClearPagePrivate2(page); 3031 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 3032 end - start + 1, uptodate)) 3033 return 0; 3034 3035 if (btrfs_is_free_space_inode(inode)) { 3036 wq = root->fs_info->endio_freespace_worker; 3037 func = btrfs_freespace_write_helper; 3038 } else { 3039 wq = root->fs_info->endio_write_workers; 3040 func = btrfs_endio_write_helper; 3041 } 3042 3043 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL, 3044 NULL); 3045 btrfs_queue_work(wq, &ordered_extent->work); 3046 3047 return 0; 3048 } 3049 3050 static int __readpage_endio_check(struct inode *inode, 3051 struct btrfs_io_bio *io_bio, 3052 int icsum, struct page *page, 3053 int pgoff, u64 start, size_t len) 3054 { 3055 char *kaddr; 3056 u32 csum_expected; 3057 u32 csum = ~(u32)0; 3058 3059 csum_expected = *(((u32 *)io_bio->csum) + icsum); 3060 3061 kaddr = kmap_atomic(page); 3062 csum = btrfs_csum_data(kaddr + pgoff, csum, len); 3063 btrfs_csum_final(csum, (char *)&csum); 3064 if (csum != csum_expected) 3065 goto zeroit; 3066 3067 kunmap_atomic(kaddr); 3068 return 0; 3069 zeroit: 3070 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info, 3071 "csum failed ino %llu off %llu csum %u expected csum %u", 3072 btrfs_ino(inode), start, csum, csum_expected); 3073 memset(kaddr + pgoff, 1, len); 3074 flush_dcache_page(page); 3075 kunmap_atomic(kaddr); 3076 if (csum_expected == 0) 3077 return 0; 3078 return -EIO; 3079 } 3080 3081 /* 3082 * when reads are done, we need to check csums to verify the data is correct 3083 * if there's a match, we allow the bio to finish. If not, the code in 3084 * extent_io.c will try to find good copies for us. 3085 */ 3086 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 3087 u64 phy_offset, struct page *page, 3088 u64 start, u64 end, int mirror) 3089 { 3090 size_t offset = start - page_offset(page); 3091 struct inode *inode = page->mapping->host; 3092 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 3093 struct btrfs_root *root = BTRFS_I(inode)->root; 3094 3095 if (PageChecked(page)) { 3096 ClearPageChecked(page); 3097 return 0; 3098 } 3099 3100 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 3101 return 0; 3102 3103 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 3104 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 3105 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, 3106 GFP_NOFS); 3107 return 0; 3108 } 3109 3110 phy_offset >>= inode->i_sb->s_blocksize_bits; 3111 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset, 3112 start, (size_t)(end - start + 1)); 3113 } 3114 3115 void btrfs_add_delayed_iput(struct inode *inode) 3116 { 3117 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; 3118 struct btrfs_inode *binode = BTRFS_I(inode); 3119 3120 if (atomic_add_unless(&inode->i_count, -1, 1)) 3121 return; 3122 3123 spin_lock(&fs_info->delayed_iput_lock); 3124 if (binode->delayed_iput_count == 0) { 3125 ASSERT(list_empty(&binode->delayed_iput)); 3126 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs); 3127 } else { 3128 binode->delayed_iput_count++; 3129 } 3130 spin_unlock(&fs_info->delayed_iput_lock); 3131 } 3132 3133 void btrfs_run_delayed_iputs(struct btrfs_root *root) 3134 { 3135 struct btrfs_fs_info *fs_info = root->fs_info; 3136 3137 spin_lock(&fs_info->delayed_iput_lock); 3138 while (!list_empty(&fs_info->delayed_iputs)) { 3139 struct btrfs_inode *inode; 3140 3141 inode = list_first_entry(&fs_info->delayed_iputs, 3142 struct btrfs_inode, delayed_iput); 3143 if (inode->delayed_iput_count) { 3144 inode->delayed_iput_count--; 3145 list_move_tail(&inode->delayed_iput, 3146 &fs_info->delayed_iputs); 3147 } else { 3148 list_del_init(&inode->delayed_iput); 3149 } 3150 spin_unlock(&fs_info->delayed_iput_lock); 3151 iput(&inode->vfs_inode); 3152 spin_lock(&fs_info->delayed_iput_lock); 3153 } 3154 spin_unlock(&fs_info->delayed_iput_lock); 3155 } 3156 3157 /* 3158 * This is called in transaction commit time. If there are no orphan 3159 * files in the subvolume, it removes orphan item and frees block_rsv 3160 * structure. 3161 */ 3162 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 3163 struct btrfs_root *root) 3164 { 3165 struct btrfs_block_rsv *block_rsv; 3166 int ret; 3167 3168 if (atomic_read(&root->orphan_inodes) || 3169 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 3170 return; 3171 3172 spin_lock(&root->orphan_lock); 3173 if (atomic_read(&root->orphan_inodes)) { 3174 spin_unlock(&root->orphan_lock); 3175 return; 3176 } 3177 3178 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 3179 spin_unlock(&root->orphan_lock); 3180 return; 3181 } 3182 3183 block_rsv = root->orphan_block_rsv; 3184 root->orphan_block_rsv = NULL; 3185 spin_unlock(&root->orphan_lock); 3186 3187 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) && 3188 btrfs_root_refs(&root->root_item) > 0) { 3189 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, 3190 root->root_key.objectid); 3191 if (ret) 3192 btrfs_abort_transaction(trans, root, ret); 3193 else 3194 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, 3195 &root->state); 3196 } 3197 3198 if (block_rsv) { 3199 WARN_ON(block_rsv->size > 0); 3200 btrfs_free_block_rsv(root, block_rsv); 3201 } 3202 } 3203 3204 /* 3205 * This creates an orphan entry for the given inode in case something goes 3206 * wrong in the middle of an unlink/truncate. 3207 * 3208 * NOTE: caller of this function should reserve 5 units of metadata for 3209 * this function. 3210 */ 3211 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) 3212 { 3213 struct btrfs_root *root = BTRFS_I(inode)->root; 3214 struct btrfs_block_rsv *block_rsv = NULL; 3215 int reserve = 0; 3216 int insert = 0; 3217 int ret; 3218 3219 if (!root->orphan_block_rsv) { 3220 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 3221 if (!block_rsv) 3222 return -ENOMEM; 3223 } 3224 3225 spin_lock(&root->orphan_lock); 3226 if (!root->orphan_block_rsv) { 3227 root->orphan_block_rsv = block_rsv; 3228 } else if (block_rsv) { 3229 btrfs_free_block_rsv(root, block_rsv); 3230 block_rsv = NULL; 3231 } 3232 3233 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3234 &BTRFS_I(inode)->runtime_flags)) { 3235 #if 0 3236 /* 3237 * For proper ENOSPC handling, we should do orphan 3238 * cleanup when mounting. But this introduces backward 3239 * compatibility issue. 3240 */ 3241 if (!xchg(&root->orphan_item_inserted, 1)) 3242 insert = 2; 3243 else 3244 insert = 1; 3245 #endif 3246 insert = 1; 3247 atomic_inc(&root->orphan_inodes); 3248 } 3249 3250 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3251 &BTRFS_I(inode)->runtime_flags)) 3252 reserve = 1; 3253 spin_unlock(&root->orphan_lock); 3254 3255 /* grab metadata reservation from transaction handle */ 3256 if (reserve) { 3257 ret = btrfs_orphan_reserve_metadata(trans, inode); 3258 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ 3259 } 3260 3261 /* insert an orphan item to track this unlinked/truncated file */ 3262 if (insert >= 1) { 3263 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 3264 if (ret) { 3265 atomic_dec(&root->orphan_inodes); 3266 if (reserve) { 3267 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3268 &BTRFS_I(inode)->runtime_flags); 3269 btrfs_orphan_release_metadata(inode); 3270 } 3271 if (ret != -EEXIST) { 3272 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3273 &BTRFS_I(inode)->runtime_flags); 3274 btrfs_abort_transaction(trans, root, ret); 3275 return ret; 3276 } 3277 } 3278 ret = 0; 3279 } 3280 3281 /* insert an orphan item to track subvolume contains orphan files */ 3282 if (insert >= 2) { 3283 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, 3284 root->root_key.objectid); 3285 if (ret && ret != -EEXIST) { 3286 btrfs_abort_transaction(trans, root, ret); 3287 return ret; 3288 } 3289 } 3290 return 0; 3291 } 3292 3293 /* 3294 * We have done the truncate/delete so we can go ahead and remove the orphan 3295 * item for this particular inode. 3296 */ 3297 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3298 struct inode *inode) 3299 { 3300 struct btrfs_root *root = BTRFS_I(inode)->root; 3301 int delete_item = 0; 3302 int release_rsv = 0; 3303 int ret = 0; 3304 3305 spin_lock(&root->orphan_lock); 3306 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3307 &BTRFS_I(inode)->runtime_flags)) 3308 delete_item = 1; 3309 3310 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3311 &BTRFS_I(inode)->runtime_flags)) 3312 release_rsv = 1; 3313 spin_unlock(&root->orphan_lock); 3314 3315 if (delete_item) { 3316 atomic_dec(&root->orphan_inodes); 3317 if (trans) 3318 ret = btrfs_del_orphan_item(trans, root, 3319 btrfs_ino(inode)); 3320 } 3321 3322 if (release_rsv) 3323 btrfs_orphan_release_metadata(inode); 3324 3325 return ret; 3326 } 3327 3328 /* 3329 * this cleans up any orphans that may be left on the list from the last use 3330 * of this root. 3331 */ 3332 int btrfs_orphan_cleanup(struct btrfs_root *root) 3333 { 3334 struct btrfs_path *path; 3335 struct extent_buffer *leaf; 3336 struct btrfs_key key, found_key; 3337 struct btrfs_trans_handle *trans; 3338 struct inode *inode; 3339 u64 last_objectid = 0; 3340 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3341 3342 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3343 return 0; 3344 3345 path = btrfs_alloc_path(); 3346 if (!path) { 3347 ret = -ENOMEM; 3348 goto out; 3349 } 3350 path->reada = READA_BACK; 3351 3352 key.objectid = BTRFS_ORPHAN_OBJECTID; 3353 key.type = BTRFS_ORPHAN_ITEM_KEY; 3354 key.offset = (u64)-1; 3355 3356 while (1) { 3357 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3358 if (ret < 0) 3359 goto out; 3360 3361 /* 3362 * if ret == 0 means we found what we were searching for, which 3363 * is weird, but possible, so only screw with path if we didn't 3364 * find the key and see if we have stuff that matches 3365 */ 3366 if (ret > 0) { 3367 ret = 0; 3368 if (path->slots[0] == 0) 3369 break; 3370 path->slots[0]--; 3371 } 3372 3373 /* pull out the item */ 3374 leaf = path->nodes[0]; 3375 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3376 3377 /* make sure the item matches what we want */ 3378 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3379 break; 3380 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY) 3381 break; 3382 3383 /* release the path since we're done with it */ 3384 btrfs_release_path(path); 3385 3386 /* 3387 * this is where we are basically btrfs_lookup, without the 3388 * crossing root thing. we store the inode number in the 3389 * offset of the orphan item. 3390 */ 3391 3392 if (found_key.offset == last_objectid) { 3393 btrfs_err(root->fs_info, 3394 "Error removing orphan entry, stopping orphan cleanup"); 3395 ret = -EINVAL; 3396 goto out; 3397 } 3398 3399 last_objectid = found_key.offset; 3400 3401 found_key.objectid = found_key.offset; 3402 found_key.type = BTRFS_INODE_ITEM_KEY; 3403 found_key.offset = 0; 3404 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); 3405 ret = PTR_ERR_OR_ZERO(inode); 3406 if (ret && ret != -ESTALE) 3407 goto out; 3408 3409 if (ret == -ESTALE && root == root->fs_info->tree_root) { 3410 struct btrfs_root *dead_root; 3411 struct btrfs_fs_info *fs_info = root->fs_info; 3412 int is_dead_root = 0; 3413 3414 /* 3415 * this is an orphan in the tree root. Currently these 3416 * could come from 2 sources: 3417 * a) a snapshot deletion in progress 3418 * b) a free space cache inode 3419 * We need to distinguish those two, as the snapshot 3420 * orphan must not get deleted. 3421 * find_dead_roots already ran before us, so if this 3422 * is a snapshot deletion, we should find the root 3423 * in the dead_roots list 3424 */ 3425 spin_lock(&fs_info->trans_lock); 3426 list_for_each_entry(dead_root, &fs_info->dead_roots, 3427 root_list) { 3428 if (dead_root->root_key.objectid == 3429 found_key.objectid) { 3430 is_dead_root = 1; 3431 break; 3432 } 3433 } 3434 spin_unlock(&fs_info->trans_lock); 3435 if (is_dead_root) { 3436 /* prevent this orphan from being found again */ 3437 key.offset = found_key.objectid - 1; 3438 continue; 3439 } 3440 } 3441 /* 3442 * Inode is already gone but the orphan item is still there, 3443 * kill the orphan item. 3444 */ 3445 if (ret == -ESTALE) { 3446 trans = btrfs_start_transaction(root, 1); 3447 if (IS_ERR(trans)) { 3448 ret = PTR_ERR(trans); 3449 goto out; 3450 } 3451 btrfs_debug(root->fs_info, "auto deleting %Lu", 3452 found_key.objectid); 3453 ret = btrfs_del_orphan_item(trans, root, 3454 found_key.objectid); 3455 btrfs_end_transaction(trans, root); 3456 if (ret) 3457 goto out; 3458 continue; 3459 } 3460 3461 /* 3462 * add this inode to the orphan list so btrfs_orphan_del does 3463 * the proper thing when we hit it 3464 */ 3465 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3466 &BTRFS_I(inode)->runtime_flags); 3467 atomic_inc(&root->orphan_inodes); 3468 3469 /* if we have links, this was a truncate, lets do that */ 3470 if (inode->i_nlink) { 3471 if (WARN_ON(!S_ISREG(inode->i_mode))) { 3472 iput(inode); 3473 continue; 3474 } 3475 nr_truncate++; 3476 3477 /* 1 for the orphan item deletion. */ 3478 trans = btrfs_start_transaction(root, 1); 3479 if (IS_ERR(trans)) { 3480 iput(inode); 3481 ret = PTR_ERR(trans); 3482 goto out; 3483 } 3484 ret = btrfs_orphan_add(trans, inode); 3485 btrfs_end_transaction(trans, root); 3486 if (ret) { 3487 iput(inode); 3488 goto out; 3489 } 3490 3491 ret = btrfs_truncate(inode); 3492 if (ret) 3493 btrfs_orphan_del(NULL, inode); 3494 } else { 3495 nr_unlink++; 3496 } 3497 3498 /* this will do delete_inode and everything for us */ 3499 iput(inode); 3500 if (ret) 3501 goto out; 3502 } 3503 /* release the path since we're done with it */ 3504 btrfs_release_path(path); 3505 3506 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3507 3508 if (root->orphan_block_rsv) 3509 btrfs_block_rsv_release(root, root->orphan_block_rsv, 3510 (u64)-1); 3511 3512 if (root->orphan_block_rsv || 3513 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) { 3514 trans = btrfs_join_transaction(root); 3515 if (!IS_ERR(trans)) 3516 btrfs_end_transaction(trans, root); 3517 } 3518 3519 if (nr_unlink) 3520 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); 3521 if (nr_truncate) 3522 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); 3523 3524 out: 3525 if (ret) 3526 btrfs_err(root->fs_info, 3527 "could not do orphan cleanup %d", ret); 3528 btrfs_free_path(path); 3529 return ret; 3530 } 3531 3532 /* 3533 * very simple check to peek ahead in the leaf looking for xattrs. If we 3534 * don't find any xattrs, we know there can't be any acls. 3535 * 3536 * slot is the slot the inode is in, objectid is the objectid of the inode 3537 */ 3538 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3539 int slot, u64 objectid, 3540 int *first_xattr_slot) 3541 { 3542 u32 nritems = btrfs_header_nritems(leaf); 3543 struct btrfs_key found_key; 3544 static u64 xattr_access = 0; 3545 static u64 xattr_default = 0; 3546 int scanned = 0; 3547 3548 if (!xattr_access) { 3549 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS, 3550 strlen(XATTR_NAME_POSIX_ACL_ACCESS)); 3551 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT, 3552 strlen(XATTR_NAME_POSIX_ACL_DEFAULT)); 3553 } 3554 3555 slot++; 3556 *first_xattr_slot = -1; 3557 while (slot < nritems) { 3558 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3559 3560 /* we found a different objectid, there must not be acls */ 3561 if (found_key.objectid != objectid) 3562 return 0; 3563 3564 /* we found an xattr, assume we've got an acl */ 3565 if (found_key.type == BTRFS_XATTR_ITEM_KEY) { 3566 if (*first_xattr_slot == -1) 3567 *first_xattr_slot = slot; 3568 if (found_key.offset == xattr_access || 3569 found_key.offset == xattr_default) 3570 return 1; 3571 } 3572 3573 /* 3574 * we found a key greater than an xattr key, there can't 3575 * be any acls later on 3576 */ 3577 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3578 return 0; 3579 3580 slot++; 3581 scanned++; 3582 3583 /* 3584 * it goes inode, inode backrefs, xattrs, extents, 3585 * so if there are a ton of hard links to an inode there can 3586 * be a lot of backrefs. Don't waste time searching too hard, 3587 * this is just an optimization 3588 */ 3589 if (scanned >= 8) 3590 break; 3591 } 3592 /* we hit the end of the leaf before we found an xattr or 3593 * something larger than an xattr. We have to assume the inode 3594 * has acls 3595 */ 3596 if (*first_xattr_slot == -1) 3597 *first_xattr_slot = slot; 3598 return 1; 3599 } 3600 3601 /* 3602 * read an inode from the btree into the in-memory inode 3603 */ 3604 static void btrfs_read_locked_inode(struct inode *inode) 3605 { 3606 struct btrfs_path *path; 3607 struct extent_buffer *leaf; 3608 struct btrfs_inode_item *inode_item; 3609 struct btrfs_root *root = BTRFS_I(inode)->root; 3610 struct btrfs_key location; 3611 unsigned long ptr; 3612 int maybe_acls; 3613 u32 rdev; 3614 int ret; 3615 bool filled = false; 3616 int first_xattr_slot; 3617 3618 ret = btrfs_fill_inode(inode, &rdev); 3619 if (!ret) 3620 filled = true; 3621 3622 path = btrfs_alloc_path(); 3623 if (!path) 3624 goto make_bad; 3625 3626 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3627 3628 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3629 if (ret) 3630 goto make_bad; 3631 3632 leaf = path->nodes[0]; 3633 3634 if (filled) 3635 goto cache_index; 3636 3637 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3638 struct btrfs_inode_item); 3639 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3640 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3641 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3642 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3643 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); 3644 3645 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime); 3646 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime); 3647 3648 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime); 3649 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime); 3650 3651 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime); 3652 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime); 3653 3654 BTRFS_I(inode)->i_otime.tv_sec = 3655 btrfs_timespec_sec(leaf, &inode_item->otime); 3656 BTRFS_I(inode)->i_otime.tv_nsec = 3657 btrfs_timespec_nsec(leaf, &inode_item->otime); 3658 3659 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3660 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3661 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3662 3663 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3664 inode->i_generation = BTRFS_I(inode)->generation; 3665 inode->i_rdev = 0; 3666 rdev = btrfs_inode_rdev(leaf, inode_item); 3667 3668 BTRFS_I(inode)->index_cnt = (u64)-1; 3669 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3670 3671 cache_index: 3672 /* 3673 * If we were modified in the current generation and evicted from memory 3674 * and then re-read we need to do a full sync since we don't have any 3675 * idea about which extents were modified before we were evicted from 3676 * cache. 3677 * 3678 * This is required for both inode re-read from disk and delayed inode 3679 * in delayed_nodes_tree. 3680 */ 3681 if (BTRFS_I(inode)->last_trans == root->fs_info->generation) 3682 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3683 &BTRFS_I(inode)->runtime_flags); 3684 3685 /* 3686 * We don't persist the id of the transaction where an unlink operation 3687 * against the inode was last made. So here we assume the inode might 3688 * have been evicted, and therefore the exact value of last_unlink_trans 3689 * lost, and set it to last_trans to avoid metadata inconsistencies 3690 * between the inode and its parent if the inode is fsync'ed and the log 3691 * replayed. For example, in the scenario: 3692 * 3693 * touch mydir/foo 3694 * ln mydir/foo mydir/bar 3695 * sync 3696 * unlink mydir/bar 3697 * echo 2 > /proc/sys/vm/drop_caches # evicts inode 3698 * xfs_io -c fsync mydir/foo 3699 * <power failure> 3700 * mount fs, triggers fsync log replay 3701 * 3702 * We must make sure that when we fsync our inode foo we also log its 3703 * parent inode, otherwise after log replay the parent still has the 3704 * dentry with the "bar" name but our inode foo has a link count of 1 3705 * and doesn't have an inode ref with the name "bar" anymore. 3706 * 3707 * Setting last_unlink_trans to last_trans is a pessimistic approach, 3708 * but it guarantees correctness at the expense of ocassional full 3709 * transaction commits on fsync if our inode is a directory, or if our 3710 * inode is not a directory, logging its parent unnecessarily. 3711 */ 3712 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans; 3713 3714 path->slots[0]++; 3715 if (inode->i_nlink != 1 || 3716 path->slots[0] >= btrfs_header_nritems(leaf)) 3717 goto cache_acl; 3718 3719 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); 3720 if (location.objectid != btrfs_ino(inode)) 3721 goto cache_acl; 3722 3723 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 3724 if (location.type == BTRFS_INODE_REF_KEY) { 3725 struct btrfs_inode_ref *ref; 3726 3727 ref = (struct btrfs_inode_ref *)ptr; 3728 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); 3729 } else if (location.type == BTRFS_INODE_EXTREF_KEY) { 3730 struct btrfs_inode_extref *extref; 3731 3732 extref = (struct btrfs_inode_extref *)ptr; 3733 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, 3734 extref); 3735 } 3736 cache_acl: 3737 /* 3738 * try to precache a NULL acl entry for files that don't have 3739 * any xattrs or acls 3740 */ 3741 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3742 btrfs_ino(inode), &first_xattr_slot); 3743 if (first_xattr_slot != -1) { 3744 path->slots[0] = first_xattr_slot; 3745 ret = btrfs_load_inode_props(inode, path); 3746 if (ret) 3747 btrfs_err(root->fs_info, 3748 "error loading props for ino %llu (root %llu): %d", 3749 btrfs_ino(inode), 3750 root->root_key.objectid, ret); 3751 } 3752 btrfs_free_path(path); 3753 3754 if (!maybe_acls) 3755 cache_no_acl(inode); 3756 3757 switch (inode->i_mode & S_IFMT) { 3758 case S_IFREG: 3759 inode->i_mapping->a_ops = &btrfs_aops; 3760 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3761 inode->i_fop = &btrfs_file_operations; 3762 inode->i_op = &btrfs_file_inode_operations; 3763 break; 3764 case S_IFDIR: 3765 inode->i_fop = &btrfs_dir_file_operations; 3766 if (root == root->fs_info->tree_root) 3767 inode->i_op = &btrfs_dir_ro_inode_operations; 3768 else 3769 inode->i_op = &btrfs_dir_inode_operations; 3770 break; 3771 case S_IFLNK: 3772 inode->i_op = &btrfs_symlink_inode_operations; 3773 inode_nohighmem(inode); 3774 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3775 break; 3776 default: 3777 inode->i_op = &btrfs_special_inode_operations; 3778 init_special_inode(inode, inode->i_mode, rdev); 3779 break; 3780 } 3781 3782 btrfs_update_iflags(inode); 3783 return; 3784 3785 make_bad: 3786 btrfs_free_path(path); 3787 make_bad_inode(inode); 3788 } 3789 3790 /* 3791 * given a leaf and an inode, copy the inode fields into the leaf 3792 */ 3793 static void fill_inode_item(struct btrfs_trans_handle *trans, 3794 struct extent_buffer *leaf, 3795 struct btrfs_inode_item *item, 3796 struct inode *inode) 3797 { 3798 struct btrfs_map_token token; 3799 3800 btrfs_init_map_token(&token); 3801 3802 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3803 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3804 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3805 &token); 3806 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3807 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3808 3809 btrfs_set_token_timespec_sec(leaf, &item->atime, 3810 inode->i_atime.tv_sec, &token); 3811 btrfs_set_token_timespec_nsec(leaf, &item->atime, 3812 inode->i_atime.tv_nsec, &token); 3813 3814 btrfs_set_token_timespec_sec(leaf, &item->mtime, 3815 inode->i_mtime.tv_sec, &token); 3816 btrfs_set_token_timespec_nsec(leaf, &item->mtime, 3817 inode->i_mtime.tv_nsec, &token); 3818 3819 btrfs_set_token_timespec_sec(leaf, &item->ctime, 3820 inode->i_ctime.tv_sec, &token); 3821 btrfs_set_token_timespec_nsec(leaf, &item->ctime, 3822 inode->i_ctime.tv_nsec, &token); 3823 3824 btrfs_set_token_timespec_sec(leaf, &item->otime, 3825 BTRFS_I(inode)->i_otime.tv_sec, &token); 3826 btrfs_set_token_timespec_nsec(leaf, &item->otime, 3827 BTRFS_I(inode)->i_otime.tv_nsec, &token); 3828 3829 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3830 &token); 3831 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3832 &token); 3833 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3834 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3835 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3836 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3837 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3838 } 3839 3840 /* 3841 * copy everything in the in-memory inode into the btree. 3842 */ 3843 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3844 struct btrfs_root *root, struct inode *inode) 3845 { 3846 struct btrfs_inode_item *inode_item; 3847 struct btrfs_path *path; 3848 struct extent_buffer *leaf; 3849 int ret; 3850 3851 path = btrfs_alloc_path(); 3852 if (!path) 3853 return -ENOMEM; 3854 3855 path->leave_spinning = 1; 3856 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3857 1); 3858 if (ret) { 3859 if (ret > 0) 3860 ret = -ENOENT; 3861 goto failed; 3862 } 3863 3864 leaf = path->nodes[0]; 3865 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3866 struct btrfs_inode_item); 3867 3868 fill_inode_item(trans, leaf, inode_item, inode); 3869 btrfs_mark_buffer_dirty(leaf); 3870 btrfs_set_inode_last_trans(trans, inode); 3871 ret = 0; 3872 failed: 3873 btrfs_free_path(path); 3874 return ret; 3875 } 3876 3877 /* 3878 * copy everything in the in-memory inode into the btree. 3879 */ 3880 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3881 struct btrfs_root *root, struct inode *inode) 3882 { 3883 int ret; 3884 3885 /* 3886 * If the inode is a free space inode, we can deadlock during commit 3887 * if we put it into the delayed code. 3888 * 3889 * The data relocation inode should also be directly updated 3890 * without delay 3891 */ 3892 if (!btrfs_is_free_space_inode(inode) 3893 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 3894 && !root->fs_info->log_root_recovering) { 3895 btrfs_update_root_times(trans, root); 3896 3897 ret = btrfs_delayed_update_inode(trans, root, inode); 3898 if (!ret) 3899 btrfs_set_inode_last_trans(trans, inode); 3900 return ret; 3901 } 3902 3903 return btrfs_update_inode_item(trans, root, inode); 3904 } 3905 3906 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3907 struct btrfs_root *root, 3908 struct inode *inode) 3909 { 3910 int ret; 3911 3912 ret = btrfs_update_inode(trans, root, inode); 3913 if (ret == -ENOSPC) 3914 return btrfs_update_inode_item(trans, root, inode); 3915 return ret; 3916 } 3917 3918 /* 3919 * unlink helper that gets used here in inode.c and in the tree logging 3920 * recovery code. It remove a link in a directory with a given name, and 3921 * also drops the back refs in the inode to the directory 3922 */ 3923 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3924 struct btrfs_root *root, 3925 struct inode *dir, struct inode *inode, 3926 const char *name, int name_len) 3927 { 3928 struct btrfs_path *path; 3929 int ret = 0; 3930 struct extent_buffer *leaf; 3931 struct btrfs_dir_item *di; 3932 struct btrfs_key key; 3933 u64 index; 3934 u64 ino = btrfs_ino(inode); 3935 u64 dir_ino = btrfs_ino(dir); 3936 3937 path = btrfs_alloc_path(); 3938 if (!path) { 3939 ret = -ENOMEM; 3940 goto out; 3941 } 3942 3943 path->leave_spinning = 1; 3944 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3945 name, name_len, -1); 3946 if (IS_ERR(di)) { 3947 ret = PTR_ERR(di); 3948 goto err; 3949 } 3950 if (!di) { 3951 ret = -ENOENT; 3952 goto err; 3953 } 3954 leaf = path->nodes[0]; 3955 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3956 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3957 if (ret) 3958 goto err; 3959 btrfs_release_path(path); 3960 3961 /* 3962 * If we don't have dir index, we have to get it by looking up 3963 * the inode ref, since we get the inode ref, remove it directly, 3964 * it is unnecessary to do delayed deletion. 3965 * 3966 * But if we have dir index, needn't search inode ref to get it. 3967 * Since the inode ref is close to the inode item, it is better 3968 * that we delay to delete it, and just do this deletion when 3969 * we update the inode item. 3970 */ 3971 if (BTRFS_I(inode)->dir_index) { 3972 ret = btrfs_delayed_delete_inode_ref(inode); 3973 if (!ret) { 3974 index = BTRFS_I(inode)->dir_index; 3975 goto skip_backref; 3976 } 3977 } 3978 3979 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3980 dir_ino, &index); 3981 if (ret) { 3982 btrfs_info(root->fs_info, 3983 "failed to delete reference to %.*s, inode %llu parent %llu", 3984 name_len, name, ino, dir_ino); 3985 btrfs_abort_transaction(trans, root, ret); 3986 goto err; 3987 } 3988 skip_backref: 3989 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3990 if (ret) { 3991 btrfs_abort_transaction(trans, root, ret); 3992 goto err; 3993 } 3994 3995 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, 3996 inode, dir_ino); 3997 if (ret != 0 && ret != -ENOENT) { 3998 btrfs_abort_transaction(trans, root, ret); 3999 goto err; 4000 } 4001 4002 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, 4003 dir, index); 4004 if (ret == -ENOENT) 4005 ret = 0; 4006 else if (ret) 4007 btrfs_abort_transaction(trans, root, ret); 4008 err: 4009 btrfs_free_path(path); 4010 if (ret) 4011 goto out; 4012 4013 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 4014 inode_inc_iversion(inode); 4015 inode_inc_iversion(dir); 4016 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; 4017 ret = btrfs_update_inode(trans, root, dir); 4018 out: 4019 return ret; 4020 } 4021 4022 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 4023 struct btrfs_root *root, 4024 struct inode *dir, struct inode *inode, 4025 const char *name, int name_len) 4026 { 4027 int ret; 4028 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 4029 if (!ret) { 4030 drop_nlink(inode); 4031 ret = btrfs_update_inode(trans, root, inode); 4032 } 4033 return ret; 4034 } 4035 4036 /* 4037 * helper to start transaction for unlink and rmdir. 4038 * 4039 * unlink and rmdir are special in btrfs, they do not always free space, so 4040 * if we cannot make our reservations the normal way try and see if there is 4041 * plenty of slack room in the global reserve to migrate, otherwise we cannot 4042 * allow the unlink to occur. 4043 */ 4044 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) 4045 { 4046 struct btrfs_root *root = BTRFS_I(dir)->root; 4047 4048 /* 4049 * 1 for the possible orphan item 4050 * 1 for the dir item 4051 * 1 for the dir index 4052 * 1 for the inode ref 4053 * 1 for the inode 4054 */ 4055 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5); 4056 } 4057 4058 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 4059 { 4060 struct btrfs_root *root = BTRFS_I(dir)->root; 4061 struct btrfs_trans_handle *trans; 4062 struct inode *inode = d_inode(dentry); 4063 int ret; 4064 4065 trans = __unlink_start_trans(dir); 4066 if (IS_ERR(trans)) 4067 return PTR_ERR(trans); 4068 4069 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0); 4070 4071 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), 4072 dentry->d_name.name, dentry->d_name.len); 4073 if (ret) 4074 goto out; 4075 4076 if (inode->i_nlink == 0) { 4077 ret = btrfs_orphan_add(trans, inode); 4078 if (ret) 4079 goto out; 4080 } 4081 4082 out: 4083 btrfs_end_transaction(trans, root); 4084 btrfs_btree_balance_dirty(root); 4085 return ret; 4086 } 4087 4088 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 4089 struct btrfs_root *root, 4090 struct inode *dir, u64 objectid, 4091 const char *name, int name_len) 4092 { 4093 struct btrfs_path *path; 4094 struct extent_buffer *leaf; 4095 struct btrfs_dir_item *di; 4096 struct btrfs_key key; 4097 u64 index; 4098 int ret; 4099 u64 dir_ino = btrfs_ino(dir); 4100 4101 path = btrfs_alloc_path(); 4102 if (!path) 4103 return -ENOMEM; 4104 4105 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 4106 name, name_len, -1); 4107 if (IS_ERR_OR_NULL(di)) { 4108 if (!di) 4109 ret = -ENOENT; 4110 else 4111 ret = PTR_ERR(di); 4112 goto out; 4113 } 4114 4115 leaf = path->nodes[0]; 4116 btrfs_dir_item_key_to_cpu(leaf, di, &key); 4117 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 4118 ret = btrfs_delete_one_dir_name(trans, root, path, di); 4119 if (ret) { 4120 btrfs_abort_transaction(trans, root, ret); 4121 goto out; 4122 } 4123 btrfs_release_path(path); 4124 4125 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, 4126 objectid, root->root_key.objectid, 4127 dir_ino, &index, name, name_len); 4128 if (ret < 0) { 4129 if (ret != -ENOENT) { 4130 btrfs_abort_transaction(trans, root, ret); 4131 goto out; 4132 } 4133 di = btrfs_search_dir_index_item(root, path, dir_ino, 4134 name, name_len); 4135 if (IS_ERR_OR_NULL(di)) { 4136 if (!di) 4137 ret = -ENOENT; 4138 else 4139 ret = PTR_ERR(di); 4140 btrfs_abort_transaction(trans, root, ret); 4141 goto out; 4142 } 4143 4144 leaf = path->nodes[0]; 4145 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4146 btrfs_release_path(path); 4147 index = key.offset; 4148 } 4149 btrfs_release_path(path); 4150 4151 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 4152 if (ret) { 4153 btrfs_abort_transaction(trans, root, ret); 4154 goto out; 4155 } 4156 4157 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 4158 inode_inc_iversion(dir); 4159 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 4160 ret = btrfs_update_inode_fallback(trans, root, dir); 4161 if (ret) 4162 btrfs_abort_transaction(trans, root, ret); 4163 out: 4164 btrfs_free_path(path); 4165 return ret; 4166 } 4167 4168 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 4169 { 4170 struct inode *inode = d_inode(dentry); 4171 int err = 0; 4172 struct btrfs_root *root = BTRFS_I(dir)->root; 4173 struct btrfs_trans_handle *trans; 4174 4175 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 4176 return -ENOTEMPTY; 4177 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) 4178 return -EPERM; 4179 4180 trans = __unlink_start_trans(dir); 4181 if (IS_ERR(trans)) 4182 return PTR_ERR(trans); 4183 4184 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 4185 err = btrfs_unlink_subvol(trans, root, dir, 4186 BTRFS_I(inode)->location.objectid, 4187 dentry->d_name.name, 4188 dentry->d_name.len); 4189 goto out; 4190 } 4191 4192 err = btrfs_orphan_add(trans, inode); 4193 if (err) 4194 goto out; 4195 4196 /* now the directory is empty */ 4197 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), 4198 dentry->d_name.name, dentry->d_name.len); 4199 if (!err) 4200 btrfs_i_size_write(inode, 0); 4201 out: 4202 btrfs_end_transaction(trans, root); 4203 btrfs_btree_balance_dirty(root); 4204 4205 return err; 4206 } 4207 4208 static int truncate_space_check(struct btrfs_trans_handle *trans, 4209 struct btrfs_root *root, 4210 u64 bytes_deleted) 4211 { 4212 int ret; 4213 4214 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted); 4215 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv, 4216 bytes_deleted, BTRFS_RESERVE_NO_FLUSH); 4217 if (!ret) 4218 trans->bytes_reserved += bytes_deleted; 4219 return ret; 4220 4221 } 4222 4223 static int truncate_inline_extent(struct inode *inode, 4224 struct btrfs_path *path, 4225 struct btrfs_key *found_key, 4226 const u64 item_end, 4227 const u64 new_size) 4228 { 4229 struct extent_buffer *leaf = path->nodes[0]; 4230 int slot = path->slots[0]; 4231 struct btrfs_file_extent_item *fi; 4232 u32 size = (u32)(new_size - found_key->offset); 4233 struct btrfs_root *root = BTRFS_I(inode)->root; 4234 4235 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 4236 4237 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) { 4238 loff_t offset = new_size; 4239 loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE); 4240 4241 /* 4242 * Zero out the remaining of the last page of our inline extent, 4243 * instead of directly truncating our inline extent here - that 4244 * would be much more complex (decompressing all the data, then 4245 * compressing the truncated data, which might be bigger than 4246 * the size of the inline extent, resize the extent, etc). 4247 * We release the path because to get the page we might need to 4248 * read the extent item from disk (data not in the page cache). 4249 */ 4250 btrfs_release_path(path); 4251 return btrfs_truncate_page(inode, offset, page_end - offset, 0); 4252 } 4253 4254 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 4255 size = btrfs_file_extent_calc_inline_size(size); 4256 btrfs_truncate_item(root, path, size, 1); 4257 4258 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 4259 inode_sub_bytes(inode, item_end + 1 - new_size); 4260 4261 return 0; 4262 } 4263 4264 /* 4265 * this can truncate away extent items, csum items and directory items. 4266 * It starts at a high offset and removes keys until it can't find 4267 * any higher than new_size 4268 * 4269 * csum items that cross the new i_size are truncated to the new size 4270 * as well. 4271 * 4272 * min_type is the minimum key type to truncate down to. If set to 0, this 4273 * will kill all the items on this inode, including the INODE_ITEM_KEY. 4274 */ 4275 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 4276 struct btrfs_root *root, 4277 struct inode *inode, 4278 u64 new_size, u32 min_type) 4279 { 4280 struct btrfs_path *path; 4281 struct extent_buffer *leaf; 4282 struct btrfs_file_extent_item *fi; 4283 struct btrfs_key key; 4284 struct btrfs_key found_key; 4285 u64 extent_start = 0; 4286 u64 extent_num_bytes = 0; 4287 u64 extent_offset = 0; 4288 u64 item_end = 0; 4289 u64 last_size = new_size; 4290 u32 found_type = (u8)-1; 4291 int found_extent; 4292 int del_item; 4293 int pending_del_nr = 0; 4294 int pending_del_slot = 0; 4295 int extent_type = -1; 4296 int ret; 4297 int err = 0; 4298 u64 ino = btrfs_ino(inode); 4299 u64 bytes_deleted = 0; 4300 bool be_nice = 0; 4301 bool should_throttle = 0; 4302 bool should_end = 0; 4303 4304 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 4305 4306 /* 4307 * for non-free space inodes and ref cows, we want to back off from 4308 * time to time 4309 */ 4310 if (!btrfs_is_free_space_inode(inode) && 4311 test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 4312 be_nice = 1; 4313 4314 path = btrfs_alloc_path(); 4315 if (!path) 4316 return -ENOMEM; 4317 path->reada = READA_BACK; 4318 4319 /* 4320 * We want to drop from the next block forward in case this new size is 4321 * not block aligned since we will be keeping the last block of the 4322 * extent just the way it is. 4323 */ 4324 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 4325 root == root->fs_info->tree_root) 4326 btrfs_drop_extent_cache(inode, ALIGN(new_size, 4327 root->sectorsize), (u64)-1, 0); 4328 4329 /* 4330 * This function is also used to drop the items in the log tree before 4331 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 4332 * it is used to drop the loged items. So we shouldn't kill the delayed 4333 * items. 4334 */ 4335 if (min_type == 0 && root == BTRFS_I(inode)->root) 4336 btrfs_kill_delayed_inode_items(inode); 4337 4338 key.objectid = ino; 4339 key.offset = (u64)-1; 4340 key.type = (u8)-1; 4341 4342 search_again: 4343 /* 4344 * with a 16K leaf size and 128MB extents, you can actually queue 4345 * up a huge file in a single leaf. Most of the time that 4346 * bytes_deleted is > 0, it will be huge by the time we get here 4347 */ 4348 if (be_nice && bytes_deleted > SZ_32M) { 4349 if (btrfs_should_end_transaction(trans, root)) { 4350 err = -EAGAIN; 4351 goto error; 4352 } 4353 } 4354 4355 4356 path->leave_spinning = 1; 4357 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 4358 if (ret < 0) { 4359 err = ret; 4360 goto out; 4361 } 4362 4363 if (ret > 0) { 4364 /* there are no items in the tree for us to truncate, we're 4365 * done 4366 */ 4367 if (path->slots[0] == 0) 4368 goto out; 4369 path->slots[0]--; 4370 } 4371 4372 while (1) { 4373 fi = NULL; 4374 leaf = path->nodes[0]; 4375 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4376 found_type = found_key.type; 4377 4378 if (found_key.objectid != ino) 4379 break; 4380 4381 if (found_type < min_type) 4382 break; 4383 4384 item_end = found_key.offset; 4385 if (found_type == BTRFS_EXTENT_DATA_KEY) { 4386 fi = btrfs_item_ptr(leaf, path->slots[0], 4387 struct btrfs_file_extent_item); 4388 extent_type = btrfs_file_extent_type(leaf, fi); 4389 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4390 item_end += 4391 btrfs_file_extent_num_bytes(leaf, fi); 4392 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4393 item_end += btrfs_file_extent_inline_len(leaf, 4394 path->slots[0], fi); 4395 } 4396 item_end--; 4397 } 4398 if (found_type > min_type) { 4399 del_item = 1; 4400 } else { 4401 if (item_end < new_size) 4402 break; 4403 if (found_key.offset >= new_size) 4404 del_item = 1; 4405 else 4406 del_item = 0; 4407 } 4408 found_extent = 0; 4409 /* FIXME, shrink the extent if the ref count is only 1 */ 4410 if (found_type != BTRFS_EXTENT_DATA_KEY) 4411 goto delete; 4412 4413 if (del_item) 4414 last_size = found_key.offset; 4415 else 4416 last_size = new_size; 4417 4418 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4419 u64 num_dec; 4420 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4421 if (!del_item) { 4422 u64 orig_num_bytes = 4423 btrfs_file_extent_num_bytes(leaf, fi); 4424 extent_num_bytes = ALIGN(new_size - 4425 found_key.offset, 4426 root->sectorsize); 4427 btrfs_set_file_extent_num_bytes(leaf, fi, 4428 extent_num_bytes); 4429 num_dec = (orig_num_bytes - 4430 extent_num_bytes); 4431 if (test_bit(BTRFS_ROOT_REF_COWS, 4432 &root->state) && 4433 extent_start != 0) 4434 inode_sub_bytes(inode, num_dec); 4435 btrfs_mark_buffer_dirty(leaf); 4436 } else { 4437 extent_num_bytes = 4438 btrfs_file_extent_disk_num_bytes(leaf, 4439 fi); 4440 extent_offset = found_key.offset - 4441 btrfs_file_extent_offset(leaf, fi); 4442 4443 /* FIXME blocksize != 4096 */ 4444 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4445 if (extent_start != 0) { 4446 found_extent = 1; 4447 if (test_bit(BTRFS_ROOT_REF_COWS, 4448 &root->state)) 4449 inode_sub_bytes(inode, num_dec); 4450 } 4451 } 4452 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4453 /* 4454 * we can't truncate inline items that have had 4455 * special encodings 4456 */ 4457 if (!del_item && 4458 btrfs_file_extent_encryption(leaf, fi) == 0 && 4459 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4460 4461 /* 4462 * Need to release path in order to truncate a 4463 * compressed extent. So delete any accumulated 4464 * extent items so far. 4465 */ 4466 if (btrfs_file_extent_compression(leaf, fi) != 4467 BTRFS_COMPRESS_NONE && pending_del_nr) { 4468 err = btrfs_del_items(trans, root, path, 4469 pending_del_slot, 4470 pending_del_nr); 4471 if (err) { 4472 btrfs_abort_transaction(trans, 4473 root, 4474 err); 4475 goto error; 4476 } 4477 pending_del_nr = 0; 4478 } 4479 4480 err = truncate_inline_extent(inode, path, 4481 &found_key, 4482 item_end, 4483 new_size); 4484 if (err) { 4485 btrfs_abort_transaction(trans, 4486 root, err); 4487 goto error; 4488 } 4489 } else if (test_bit(BTRFS_ROOT_REF_COWS, 4490 &root->state)) { 4491 inode_sub_bytes(inode, item_end + 1 - new_size); 4492 } 4493 } 4494 delete: 4495 if (del_item) { 4496 if (!pending_del_nr) { 4497 /* no pending yet, add ourselves */ 4498 pending_del_slot = path->slots[0]; 4499 pending_del_nr = 1; 4500 } else if (pending_del_nr && 4501 path->slots[0] + 1 == pending_del_slot) { 4502 /* hop on the pending chunk */ 4503 pending_del_nr++; 4504 pending_del_slot = path->slots[0]; 4505 } else { 4506 BUG(); 4507 } 4508 } else { 4509 break; 4510 } 4511 should_throttle = 0; 4512 4513 if (found_extent && 4514 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 4515 root == root->fs_info->tree_root)) { 4516 btrfs_set_path_blocking(path); 4517 bytes_deleted += extent_num_bytes; 4518 ret = btrfs_free_extent(trans, root, extent_start, 4519 extent_num_bytes, 0, 4520 btrfs_header_owner(leaf), 4521 ino, extent_offset); 4522 BUG_ON(ret); 4523 if (btrfs_should_throttle_delayed_refs(trans, root)) 4524 btrfs_async_run_delayed_refs(root, 4525 trans->delayed_ref_updates * 2, 0); 4526 if (be_nice) { 4527 if (truncate_space_check(trans, root, 4528 extent_num_bytes)) { 4529 should_end = 1; 4530 } 4531 if (btrfs_should_throttle_delayed_refs(trans, 4532 root)) { 4533 should_throttle = 1; 4534 } 4535 } 4536 } 4537 4538 if (found_type == BTRFS_INODE_ITEM_KEY) 4539 break; 4540 4541 if (path->slots[0] == 0 || 4542 path->slots[0] != pending_del_slot || 4543 should_throttle || should_end) { 4544 if (pending_del_nr) { 4545 ret = btrfs_del_items(trans, root, path, 4546 pending_del_slot, 4547 pending_del_nr); 4548 if (ret) { 4549 btrfs_abort_transaction(trans, 4550 root, ret); 4551 goto error; 4552 } 4553 pending_del_nr = 0; 4554 } 4555 btrfs_release_path(path); 4556 if (should_throttle) { 4557 unsigned long updates = trans->delayed_ref_updates; 4558 if (updates) { 4559 trans->delayed_ref_updates = 0; 4560 ret = btrfs_run_delayed_refs(trans, root, updates * 2); 4561 if (ret && !err) 4562 err = ret; 4563 } 4564 } 4565 /* 4566 * if we failed to refill our space rsv, bail out 4567 * and let the transaction restart 4568 */ 4569 if (should_end) { 4570 err = -EAGAIN; 4571 goto error; 4572 } 4573 goto search_again; 4574 } else { 4575 path->slots[0]--; 4576 } 4577 } 4578 out: 4579 if (pending_del_nr) { 4580 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4581 pending_del_nr); 4582 if (ret) 4583 btrfs_abort_transaction(trans, root, ret); 4584 } 4585 error: 4586 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) 4587 btrfs_ordered_update_i_size(inode, last_size, NULL); 4588 4589 btrfs_free_path(path); 4590 4591 if (be_nice && bytes_deleted > SZ_32M) { 4592 unsigned long updates = trans->delayed_ref_updates; 4593 if (updates) { 4594 trans->delayed_ref_updates = 0; 4595 ret = btrfs_run_delayed_refs(trans, root, updates * 2); 4596 if (ret && !err) 4597 err = ret; 4598 } 4599 } 4600 return err; 4601 } 4602 4603 /* 4604 * btrfs_truncate_page - read, zero a chunk and write a page 4605 * @inode - inode that we're zeroing 4606 * @from - the offset to start zeroing 4607 * @len - the length to zero, 0 to zero the entire range respective to the 4608 * offset 4609 * @front - zero up to the offset instead of from the offset on 4610 * 4611 * This will find the page for the "from" offset and cow the page and zero the 4612 * part we want to zero. This is used with truncate and hole punching. 4613 */ 4614 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, 4615 int front) 4616 { 4617 struct address_space *mapping = inode->i_mapping; 4618 struct btrfs_root *root = BTRFS_I(inode)->root; 4619 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4620 struct btrfs_ordered_extent *ordered; 4621 struct extent_state *cached_state = NULL; 4622 char *kaddr; 4623 u32 blocksize = root->sectorsize; 4624 pgoff_t index = from >> PAGE_CACHE_SHIFT; 4625 unsigned offset = from & (PAGE_CACHE_SIZE-1); 4626 struct page *page; 4627 gfp_t mask = btrfs_alloc_write_mask(mapping); 4628 int ret = 0; 4629 u64 page_start; 4630 u64 page_end; 4631 4632 if ((offset & (blocksize - 1)) == 0 && 4633 (!len || ((len & (blocksize - 1)) == 0))) 4634 goto out; 4635 ret = btrfs_delalloc_reserve_space(inode, 4636 round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE); 4637 if (ret) 4638 goto out; 4639 4640 again: 4641 page = find_or_create_page(mapping, index, mask); 4642 if (!page) { 4643 btrfs_delalloc_release_space(inode, 4644 round_down(from, PAGE_CACHE_SIZE), 4645 PAGE_CACHE_SIZE); 4646 ret = -ENOMEM; 4647 goto out; 4648 } 4649 4650 page_start = page_offset(page); 4651 page_end = page_start + PAGE_CACHE_SIZE - 1; 4652 4653 if (!PageUptodate(page)) { 4654 ret = btrfs_readpage(NULL, page); 4655 lock_page(page); 4656 if (page->mapping != mapping) { 4657 unlock_page(page); 4658 page_cache_release(page); 4659 goto again; 4660 } 4661 if (!PageUptodate(page)) { 4662 ret = -EIO; 4663 goto out_unlock; 4664 } 4665 } 4666 wait_on_page_writeback(page); 4667 4668 lock_extent_bits(io_tree, page_start, page_end, &cached_state); 4669 set_page_extent_mapped(page); 4670 4671 ordered = btrfs_lookup_ordered_extent(inode, page_start); 4672 if (ordered) { 4673 unlock_extent_cached(io_tree, page_start, page_end, 4674 &cached_state, GFP_NOFS); 4675 unlock_page(page); 4676 page_cache_release(page); 4677 btrfs_start_ordered_extent(inode, ordered, 1); 4678 btrfs_put_ordered_extent(ordered); 4679 goto again; 4680 } 4681 4682 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 4683 EXTENT_DIRTY | EXTENT_DELALLOC | 4684 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4685 0, 0, &cached_state, GFP_NOFS); 4686 4687 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 4688 &cached_state); 4689 if (ret) { 4690 unlock_extent_cached(io_tree, page_start, page_end, 4691 &cached_state, GFP_NOFS); 4692 goto out_unlock; 4693 } 4694 4695 if (offset != PAGE_CACHE_SIZE) { 4696 if (!len) 4697 len = PAGE_CACHE_SIZE - offset; 4698 kaddr = kmap(page); 4699 if (front) 4700 memset(kaddr, 0, offset); 4701 else 4702 memset(kaddr + offset, 0, len); 4703 flush_dcache_page(page); 4704 kunmap(page); 4705 } 4706 ClearPageChecked(page); 4707 set_page_dirty(page); 4708 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, 4709 GFP_NOFS); 4710 4711 out_unlock: 4712 if (ret) 4713 btrfs_delalloc_release_space(inode, page_start, 4714 PAGE_CACHE_SIZE); 4715 unlock_page(page); 4716 page_cache_release(page); 4717 out: 4718 return ret; 4719 } 4720 4721 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, 4722 u64 offset, u64 len) 4723 { 4724 struct btrfs_trans_handle *trans; 4725 int ret; 4726 4727 /* 4728 * Still need to make sure the inode looks like it's been updated so 4729 * that any holes get logged if we fsync. 4730 */ 4731 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) { 4732 BTRFS_I(inode)->last_trans = root->fs_info->generation; 4733 BTRFS_I(inode)->last_sub_trans = root->log_transid; 4734 BTRFS_I(inode)->last_log_commit = root->last_log_commit; 4735 return 0; 4736 } 4737 4738 /* 4739 * 1 - for the one we're dropping 4740 * 1 - for the one we're adding 4741 * 1 - for updating the inode. 4742 */ 4743 trans = btrfs_start_transaction(root, 3); 4744 if (IS_ERR(trans)) 4745 return PTR_ERR(trans); 4746 4747 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); 4748 if (ret) { 4749 btrfs_abort_transaction(trans, root, ret); 4750 btrfs_end_transaction(trans, root); 4751 return ret; 4752 } 4753 4754 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, 4755 0, 0, len, 0, len, 0, 0, 0); 4756 if (ret) 4757 btrfs_abort_transaction(trans, root, ret); 4758 else 4759 btrfs_update_inode(trans, root, inode); 4760 btrfs_end_transaction(trans, root); 4761 return ret; 4762 } 4763 4764 /* 4765 * This function puts in dummy file extents for the area we're creating a hole 4766 * for. So if we are truncating this file to a larger size we need to insert 4767 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4768 * the range between oldsize and size 4769 */ 4770 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4771 { 4772 struct btrfs_root *root = BTRFS_I(inode)->root; 4773 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4774 struct extent_map *em = NULL; 4775 struct extent_state *cached_state = NULL; 4776 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4777 u64 hole_start = ALIGN(oldsize, root->sectorsize); 4778 u64 block_end = ALIGN(size, root->sectorsize); 4779 u64 last_byte; 4780 u64 cur_offset; 4781 u64 hole_size; 4782 int err = 0; 4783 4784 /* 4785 * If our size started in the middle of a page we need to zero out the 4786 * rest of the page before we expand the i_size, otherwise we could 4787 * expose stale data. 4788 */ 4789 err = btrfs_truncate_page(inode, oldsize, 0, 0); 4790 if (err) 4791 return err; 4792 4793 if (size <= hole_start) 4794 return 0; 4795 4796 while (1) { 4797 struct btrfs_ordered_extent *ordered; 4798 4799 lock_extent_bits(io_tree, hole_start, block_end - 1, 4800 &cached_state); 4801 ordered = btrfs_lookup_ordered_range(inode, hole_start, 4802 block_end - hole_start); 4803 if (!ordered) 4804 break; 4805 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4806 &cached_state, GFP_NOFS); 4807 btrfs_start_ordered_extent(inode, ordered, 1); 4808 btrfs_put_ordered_extent(ordered); 4809 } 4810 4811 cur_offset = hole_start; 4812 while (1) { 4813 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 4814 block_end - cur_offset, 0); 4815 if (IS_ERR(em)) { 4816 err = PTR_ERR(em); 4817 em = NULL; 4818 break; 4819 } 4820 last_byte = min(extent_map_end(em), block_end); 4821 last_byte = ALIGN(last_byte , root->sectorsize); 4822 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4823 struct extent_map *hole_em; 4824 hole_size = last_byte - cur_offset; 4825 4826 err = maybe_insert_hole(root, inode, cur_offset, 4827 hole_size); 4828 if (err) 4829 break; 4830 btrfs_drop_extent_cache(inode, cur_offset, 4831 cur_offset + hole_size - 1, 0); 4832 hole_em = alloc_extent_map(); 4833 if (!hole_em) { 4834 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4835 &BTRFS_I(inode)->runtime_flags); 4836 goto next; 4837 } 4838 hole_em->start = cur_offset; 4839 hole_em->len = hole_size; 4840 hole_em->orig_start = cur_offset; 4841 4842 hole_em->block_start = EXTENT_MAP_HOLE; 4843 hole_em->block_len = 0; 4844 hole_em->orig_block_len = 0; 4845 hole_em->ram_bytes = hole_size; 4846 hole_em->bdev = root->fs_info->fs_devices->latest_bdev; 4847 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4848 hole_em->generation = root->fs_info->generation; 4849 4850 while (1) { 4851 write_lock(&em_tree->lock); 4852 err = add_extent_mapping(em_tree, hole_em, 1); 4853 write_unlock(&em_tree->lock); 4854 if (err != -EEXIST) 4855 break; 4856 btrfs_drop_extent_cache(inode, cur_offset, 4857 cur_offset + 4858 hole_size - 1, 0); 4859 } 4860 free_extent_map(hole_em); 4861 } 4862 next: 4863 free_extent_map(em); 4864 em = NULL; 4865 cur_offset = last_byte; 4866 if (cur_offset >= block_end) 4867 break; 4868 } 4869 free_extent_map(em); 4870 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4871 GFP_NOFS); 4872 return err; 4873 } 4874 4875 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4876 { 4877 struct btrfs_root *root = BTRFS_I(inode)->root; 4878 struct btrfs_trans_handle *trans; 4879 loff_t oldsize = i_size_read(inode); 4880 loff_t newsize = attr->ia_size; 4881 int mask = attr->ia_valid; 4882 int ret; 4883 4884 /* 4885 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4886 * special case where we need to update the times despite not having 4887 * these flags set. For all other operations the VFS set these flags 4888 * explicitly if it wants a timestamp update. 4889 */ 4890 if (newsize != oldsize) { 4891 inode_inc_iversion(inode); 4892 if (!(mask & (ATTR_CTIME | ATTR_MTIME))) 4893 inode->i_ctime = inode->i_mtime = 4894 current_fs_time(inode->i_sb); 4895 } 4896 4897 if (newsize > oldsize) { 4898 truncate_pagecache(inode, newsize); 4899 /* 4900 * Don't do an expanding truncate while snapshoting is ongoing. 4901 * This is to ensure the snapshot captures a fully consistent 4902 * state of this file - if the snapshot captures this expanding 4903 * truncation, it must capture all writes that happened before 4904 * this truncation. 4905 */ 4906 btrfs_wait_for_snapshot_creation(root); 4907 ret = btrfs_cont_expand(inode, oldsize, newsize); 4908 if (ret) { 4909 btrfs_end_write_no_snapshoting(root); 4910 return ret; 4911 } 4912 4913 trans = btrfs_start_transaction(root, 1); 4914 if (IS_ERR(trans)) { 4915 btrfs_end_write_no_snapshoting(root); 4916 return PTR_ERR(trans); 4917 } 4918 4919 i_size_write(inode, newsize); 4920 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4921 ret = btrfs_update_inode(trans, root, inode); 4922 btrfs_end_write_no_snapshoting(root); 4923 btrfs_end_transaction(trans, root); 4924 } else { 4925 4926 /* 4927 * We're truncating a file that used to have good data down to 4928 * zero. Make sure it gets into the ordered flush list so that 4929 * any new writes get down to disk quickly. 4930 */ 4931 if (newsize == 0) 4932 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4933 &BTRFS_I(inode)->runtime_flags); 4934 4935 /* 4936 * 1 for the orphan item we're going to add 4937 * 1 for the orphan item deletion. 4938 */ 4939 trans = btrfs_start_transaction(root, 2); 4940 if (IS_ERR(trans)) 4941 return PTR_ERR(trans); 4942 4943 /* 4944 * We need to do this in case we fail at _any_ point during the 4945 * actual truncate. Once we do the truncate_setsize we could 4946 * invalidate pages which forces any outstanding ordered io to 4947 * be instantly completed which will give us extents that need 4948 * to be truncated. If we fail to get an orphan inode down we 4949 * could have left over extents that were never meant to live, 4950 * so we need to garuntee from this point on that everything 4951 * will be consistent. 4952 */ 4953 ret = btrfs_orphan_add(trans, inode); 4954 btrfs_end_transaction(trans, root); 4955 if (ret) 4956 return ret; 4957 4958 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4959 truncate_setsize(inode, newsize); 4960 4961 /* Disable nonlocked read DIO to avoid the end less truncate */ 4962 btrfs_inode_block_unlocked_dio(inode); 4963 inode_dio_wait(inode); 4964 btrfs_inode_resume_unlocked_dio(inode); 4965 4966 ret = btrfs_truncate(inode); 4967 if (ret && inode->i_nlink) { 4968 int err; 4969 4970 /* 4971 * failed to truncate, disk_i_size is only adjusted down 4972 * as we remove extents, so it should represent the true 4973 * size of the inode, so reset the in memory size and 4974 * delete our orphan entry. 4975 */ 4976 trans = btrfs_join_transaction(root); 4977 if (IS_ERR(trans)) { 4978 btrfs_orphan_del(NULL, inode); 4979 return ret; 4980 } 4981 i_size_write(inode, BTRFS_I(inode)->disk_i_size); 4982 err = btrfs_orphan_del(trans, inode); 4983 if (err) 4984 btrfs_abort_transaction(trans, root, err); 4985 btrfs_end_transaction(trans, root); 4986 } 4987 } 4988 4989 return ret; 4990 } 4991 4992 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 4993 { 4994 struct inode *inode = d_inode(dentry); 4995 struct btrfs_root *root = BTRFS_I(inode)->root; 4996 int err; 4997 4998 if (btrfs_root_readonly(root)) 4999 return -EROFS; 5000 5001 err = inode_change_ok(inode, attr); 5002 if (err) 5003 return err; 5004 5005 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 5006 err = btrfs_setsize(inode, attr); 5007 if (err) 5008 return err; 5009 } 5010 5011 if (attr->ia_valid) { 5012 setattr_copy(inode, attr); 5013 inode_inc_iversion(inode); 5014 err = btrfs_dirty_inode(inode); 5015 5016 if (!err && attr->ia_valid & ATTR_MODE) 5017 err = posix_acl_chmod(inode, inode->i_mode); 5018 } 5019 5020 return err; 5021 } 5022 5023 /* 5024 * While truncating the inode pages during eviction, we get the VFS calling 5025 * btrfs_invalidatepage() against each page of the inode. This is slow because 5026 * the calls to btrfs_invalidatepage() result in a huge amount of calls to 5027 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting 5028 * extent_state structures over and over, wasting lots of time. 5029 * 5030 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all 5031 * those expensive operations on a per page basis and do only the ordered io 5032 * finishing, while we release here the extent_map and extent_state structures, 5033 * without the excessive merging and splitting. 5034 */ 5035 static void evict_inode_truncate_pages(struct inode *inode) 5036 { 5037 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 5038 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; 5039 struct rb_node *node; 5040 5041 ASSERT(inode->i_state & I_FREEING); 5042 truncate_inode_pages_final(&inode->i_data); 5043 5044 write_lock(&map_tree->lock); 5045 while (!RB_EMPTY_ROOT(&map_tree->map)) { 5046 struct extent_map *em; 5047 5048 node = rb_first(&map_tree->map); 5049 em = rb_entry(node, struct extent_map, rb_node); 5050 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 5051 clear_bit(EXTENT_FLAG_LOGGING, &em->flags); 5052 remove_extent_mapping(map_tree, em); 5053 free_extent_map(em); 5054 if (need_resched()) { 5055 write_unlock(&map_tree->lock); 5056 cond_resched(); 5057 write_lock(&map_tree->lock); 5058 } 5059 } 5060 write_unlock(&map_tree->lock); 5061 5062 /* 5063 * Keep looping until we have no more ranges in the io tree. 5064 * We can have ongoing bios started by readpages (called from readahead) 5065 * that have their endio callback (extent_io.c:end_bio_extent_readpage) 5066 * still in progress (unlocked the pages in the bio but did not yet 5067 * unlocked the ranges in the io tree). Therefore this means some 5068 * ranges can still be locked and eviction started because before 5069 * submitting those bios, which are executed by a separate task (work 5070 * queue kthread), inode references (inode->i_count) were not taken 5071 * (which would be dropped in the end io callback of each bio). 5072 * Therefore here we effectively end up waiting for those bios and 5073 * anyone else holding locked ranges without having bumped the inode's 5074 * reference count - if we don't do it, when they access the inode's 5075 * io_tree to unlock a range it may be too late, leading to an 5076 * use-after-free issue. 5077 */ 5078 spin_lock(&io_tree->lock); 5079 while (!RB_EMPTY_ROOT(&io_tree->state)) { 5080 struct extent_state *state; 5081 struct extent_state *cached_state = NULL; 5082 u64 start; 5083 u64 end; 5084 5085 node = rb_first(&io_tree->state); 5086 state = rb_entry(node, struct extent_state, rb_node); 5087 start = state->start; 5088 end = state->end; 5089 spin_unlock(&io_tree->lock); 5090 5091 lock_extent_bits(io_tree, start, end, &cached_state); 5092 5093 /* 5094 * If still has DELALLOC flag, the extent didn't reach disk, 5095 * and its reserved space won't be freed by delayed_ref. 5096 * So we need to free its reserved space here. 5097 * (Refer to comment in btrfs_invalidatepage, case 2) 5098 * 5099 * Note, end is the bytenr of last byte, so we need + 1 here. 5100 */ 5101 if (state->state & EXTENT_DELALLOC) 5102 btrfs_qgroup_free_data(inode, start, end - start + 1); 5103 5104 clear_extent_bit(io_tree, start, end, 5105 EXTENT_LOCKED | EXTENT_DIRTY | 5106 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 5107 EXTENT_DEFRAG, 1, 1, 5108 &cached_state, GFP_NOFS); 5109 5110 cond_resched(); 5111 spin_lock(&io_tree->lock); 5112 } 5113 spin_unlock(&io_tree->lock); 5114 } 5115 5116 void btrfs_evict_inode(struct inode *inode) 5117 { 5118 struct btrfs_trans_handle *trans; 5119 struct btrfs_root *root = BTRFS_I(inode)->root; 5120 struct btrfs_block_rsv *rsv, *global_rsv; 5121 int steal_from_global = 0; 5122 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 5123 int ret; 5124 5125 trace_btrfs_inode_evict(inode); 5126 5127 evict_inode_truncate_pages(inode); 5128 5129 if (inode->i_nlink && 5130 ((btrfs_root_refs(&root->root_item) != 0 && 5131 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || 5132 btrfs_is_free_space_inode(inode))) 5133 goto no_delete; 5134 5135 if (is_bad_inode(inode)) { 5136 btrfs_orphan_del(NULL, inode); 5137 goto no_delete; 5138 } 5139 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 5140 if (!special_file(inode->i_mode)) 5141 btrfs_wait_ordered_range(inode, 0, (u64)-1); 5142 5143 btrfs_free_io_failure_record(inode, 0, (u64)-1); 5144 5145 if (root->fs_info->log_root_recovering) { 5146 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 5147 &BTRFS_I(inode)->runtime_flags)); 5148 goto no_delete; 5149 } 5150 5151 if (inode->i_nlink > 0) { 5152 BUG_ON(btrfs_root_refs(&root->root_item) != 0 && 5153 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); 5154 goto no_delete; 5155 } 5156 5157 ret = btrfs_commit_inode_delayed_inode(inode); 5158 if (ret) { 5159 btrfs_orphan_del(NULL, inode); 5160 goto no_delete; 5161 } 5162 5163 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 5164 if (!rsv) { 5165 btrfs_orphan_del(NULL, inode); 5166 goto no_delete; 5167 } 5168 rsv->size = min_size; 5169 rsv->failfast = 1; 5170 global_rsv = &root->fs_info->global_block_rsv; 5171 5172 btrfs_i_size_write(inode, 0); 5173 5174 /* 5175 * This is a bit simpler than btrfs_truncate since we've already 5176 * reserved our space for our orphan item in the unlink, so we just 5177 * need to reserve some slack space in case we add bytes and update 5178 * inode item when doing the truncate. 5179 */ 5180 while (1) { 5181 ret = btrfs_block_rsv_refill(root, rsv, min_size, 5182 BTRFS_RESERVE_FLUSH_LIMIT); 5183 5184 /* 5185 * Try and steal from the global reserve since we will 5186 * likely not use this space anyway, we want to try as 5187 * hard as possible to get this to work. 5188 */ 5189 if (ret) 5190 steal_from_global++; 5191 else 5192 steal_from_global = 0; 5193 ret = 0; 5194 5195 /* 5196 * steal_from_global == 0: we reserved stuff, hooray! 5197 * steal_from_global == 1: we didn't reserve stuff, boo! 5198 * steal_from_global == 2: we've committed, still not a lot of 5199 * room but maybe we'll have room in the global reserve this 5200 * time. 5201 * steal_from_global == 3: abandon all hope! 5202 */ 5203 if (steal_from_global > 2) { 5204 btrfs_warn(root->fs_info, 5205 "Could not get space for a delete, will truncate on mount %d", 5206 ret); 5207 btrfs_orphan_del(NULL, inode); 5208 btrfs_free_block_rsv(root, rsv); 5209 goto no_delete; 5210 } 5211 5212 trans = btrfs_join_transaction(root); 5213 if (IS_ERR(trans)) { 5214 btrfs_orphan_del(NULL, inode); 5215 btrfs_free_block_rsv(root, rsv); 5216 goto no_delete; 5217 } 5218 5219 /* 5220 * We can't just steal from the global reserve, we need tomake 5221 * sure there is room to do it, if not we need to commit and try 5222 * again. 5223 */ 5224 if (steal_from_global) { 5225 if (!btrfs_check_space_for_delayed_refs(trans, root)) 5226 ret = btrfs_block_rsv_migrate(global_rsv, rsv, 5227 min_size); 5228 else 5229 ret = -ENOSPC; 5230 } 5231 5232 /* 5233 * Couldn't steal from the global reserve, we have too much 5234 * pending stuff built up, commit the transaction and try it 5235 * again. 5236 */ 5237 if (ret) { 5238 ret = btrfs_commit_transaction(trans, root); 5239 if (ret) { 5240 btrfs_orphan_del(NULL, inode); 5241 btrfs_free_block_rsv(root, rsv); 5242 goto no_delete; 5243 } 5244 continue; 5245 } else { 5246 steal_from_global = 0; 5247 } 5248 5249 trans->block_rsv = rsv; 5250 5251 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 5252 if (ret != -ENOSPC && ret != -EAGAIN) 5253 break; 5254 5255 trans->block_rsv = &root->fs_info->trans_block_rsv; 5256 btrfs_end_transaction(trans, root); 5257 trans = NULL; 5258 btrfs_btree_balance_dirty(root); 5259 } 5260 5261 btrfs_free_block_rsv(root, rsv); 5262 5263 /* 5264 * Errors here aren't a big deal, it just means we leave orphan items 5265 * in the tree. They will be cleaned up on the next mount. 5266 */ 5267 if (ret == 0) { 5268 trans->block_rsv = root->orphan_block_rsv; 5269 btrfs_orphan_del(trans, inode); 5270 } else { 5271 btrfs_orphan_del(NULL, inode); 5272 } 5273 5274 trans->block_rsv = &root->fs_info->trans_block_rsv; 5275 if (!(root == root->fs_info->tree_root || 5276 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 5277 btrfs_return_ino(root, btrfs_ino(inode)); 5278 5279 btrfs_end_transaction(trans, root); 5280 btrfs_btree_balance_dirty(root); 5281 no_delete: 5282 btrfs_remove_delayed_node(inode); 5283 clear_inode(inode); 5284 } 5285 5286 /* 5287 * this returns the key found in the dir entry in the location pointer. 5288 * If no dir entries were found, location->objectid is 0. 5289 */ 5290 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 5291 struct btrfs_key *location) 5292 { 5293 const char *name = dentry->d_name.name; 5294 int namelen = dentry->d_name.len; 5295 struct btrfs_dir_item *di; 5296 struct btrfs_path *path; 5297 struct btrfs_root *root = BTRFS_I(dir)->root; 5298 int ret = 0; 5299 5300 path = btrfs_alloc_path(); 5301 if (!path) 5302 return -ENOMEM; 5303 5304 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, 5305 namelen, 0); 5306 if (IS_ERR(di)) 5307 ret = PTR_ERR(di); 5308 5309 if (IS_ERR_OR_NULL(di)) 5310 goto out_err; 5311 5312 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 5313 out: 5314 btrfs_free_path(path); 5315 return ret; 5316 out_err: 5317 location->objectid = 0; 5318 goto out; 5319 } 5320 5321 /* 5322 * when we hit a tree root in a directory, the btrfs part of the inode 5323 * needs to be changed to reflect the root directory of the tree root. This 5324 * is kind of like crossing a mount point. 5325 */ 5326 static int fixup_tree_root_location(struct btrfs_root *root, 5327 struct inode *dir, 5328 struct dentry *dentry, 5329 struct btrfs_key *location, 5330 struct btrfs_root **sub_root) 5331 { 5332 struct btrfs_path *path; 5333 struct btrfs_root *new_root; 5334 struct btrfs_root_ref *ref; 5335 struct extent_buffer *leaf; 5336 struct btrfs_key key; 5337 int ret; 5338 int err = 0; 5339 5340 path = btrfs_alloc_path(); 5341 if (!path) { 5342 err = -ENOMEM; 5343 goto out; 5344 } 5345 5346 err = -ENOENT; 5347 key.objectid = BTRFS_I(dir)->root->root_key.objectid; 5348 key.type = BTRFS_ROOT_REF_KEY; 5349 key.offset = location->objectid; 5350 5351 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path, 5352 0, 0); 5353 if (ret) { 5354 if (ret < 0) 5355 err = ret; 5356 goto out; 5357 } 5358 5359 leaf = path->nodes[0]; 5360 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 5361 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || 5362 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 5363 goto out; 5364 5365 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 5366 (unsigned long)(ref + 1), 5367 dentry->d_name.len); 5368 if (ret) 5369 goto out; 5370 5371 btrfs_release_path(path); 5372 5373 new_root = btrfs_read_fs_root_no_name(root->fs_info, location); 5374 if (IS_ERR(new_root)) { 5375 err = PTR_ERR(new_root); 5376 goto out; 5377 } 5378 5379 *sub_root = new_root; 5380 location->objectid = btrfs_root_dirid(&new_root->root_item); 5381 location->type = BTRFS_INODE_ITEM_KEY; 5382 location->offset = 0; 5383 err = 0; 5384 out: 5385 btrfs_free_path(path); 5386 return err; 5387 } 5388 5389 static void inode_tree_add(struct inode *inode) 5390 { 5391 struct btrfs_root *root = BTRFS_I(inode)->root; 5392 struct btrfs_inode *entry; 5393 struct rb_node **p; 5394 struct rb_node *parent; 5395 struct rb_node *new = &BTRFS_I(inode)->rb_node; 5396 u64 ino = btrfs_ino(inode); 5397 5398 if (inode_unhashed(inode)) 5399 return; 5400 parent = NULL; 5401 spin_lock(&root->inode_lock); 5402 p = &root->inode_tree.rb_node; 5403 while (*p) { 5404 parent = *p; 5405 entry = rb_entry(parent, struct btrfs_inode, rb_node); 5406 5407 if (ino < btrfs_ino(&entry->vfs_inode)) 5408 p = &parent->rb_left; 5409 else if (ino > btrfs_ino(&entry->vfs_inode)) 5410 p = &parent->rb_right; 5411 else { 5412 WARN_ON(!(entry->vfs_inode.i_state & 5413 (I_WILL_FREE | I_FREEING))); 5414 rb_replace_node(parent, new, &root->inode_tree); 5415 RB_CLEAR_NODE(parent); 5416 spin_unlock(&root->inode_lock); 5417 return; 5418 } 5419 } 5420 rb_link_node(new, parent, p); 5421 rb_insert_color(new, &root->inode_tree); 5422 spin_unlock(&root->inode_lock); 5423 } 5424 5425 static void inode_tree_del(struct inode *inode) 5426 { 5427 struct btrfs_root *root = BTRFS_I(inode)->root; 5428 int empty = 0; 5429 5430 spin_lock(&root->inode_lock); 5431 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 5432 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 5433 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 5434 empty = RB_EMPTY_ROOT(&root->inode_tree); 5435 } 5436 spin_unlock(&root->inode_lock); 5437 5438 if (empty && btrfs_root_refs(&root->root_item) == 0) { 5439 synchronize_srcu(&root->fs_info->subvol_srcu); 5440 spin_lock(&root->inode_lock); 5441 empty = RB_EMPTY_ROOT(&root->inode_tree); 5442 spin_unlock(&root->inode_lock); 5443 if (empty) 5444 btrfs_add_dead_root(root); 5445 } 5446 } 5447 5448 void btrfs_invalidate_inodes(struct btrfs_root *root) 5449 { 5450 struct rb_node *node; 5451 struct rb_node *prev; 5452 struct btrfs_inode *entry; 5453 struct inode *inode; 5454 u64 objectid = 0; 5455 5456 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 5457 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 5458 5459 spin_lock(&root->inode_lock); 5460 again: 5461 node = root->inode_tree.rb_node; 5462 prev = NULL; 5463 while (node) { 5464 prev = node; 5465 entry = rb_entry(node, struct btrfs_inode, rb_node); 5466 5467 if (objectid < btrfs_ino(&entry->vfs_inode)) 5468 node = node->rb_left; 5469 else if (objectid > btrfs_ino(&entry->vfs_inode)) 5470 node = node->rb_right; 5471 else 5472 break; 5473 } 5474 if (!node) { 5475 while (prev) { 5476 entry = rb_entry(prev, struct btrfs_inode, rb_node); 5477 if (objectid <= btrfs_ino(&entry->vfs_inode)) { 5478 node = prev; 5479 break; 5480 } 5481 prev = rb_next(prev); 5482 } 5483 } 5484 while (node) { 5485 entry = rb_entry(node, struct btrfs_inode, rb_node); 5486 objectid = btrfs_ino(&entry->vfs_inode) + 1; 5487 inode = igrab(&entry->vfs_inode); 5488 if (inode) { 5489 spin_unlock(&root->inode_lock); 5490 if (atomic_read(&inode->i_count) > 1) 5491 d_prune_aliases(inode); 5492 /* 5493 * btrfs_drop_inode will have it removed from 5494 * the inode cache when its usage count 5495 * hits zero. 5496 */ 5497 iput(inode); 5498 cond_resched(); 5499 spin_lock(&root->inode_lock); 5500 goto again; 5501 } 5502 5503 if (cond_resched_lock(&root->inode_lock)) 5504 goto again; 5505 5506 node = rb_next(node); 5507 } 5508 spin_unlock(&root->inode_lock); 5509 } 5510 5511 static int btrfs_init_locked_inode(struct inode *inode, void *p) 5512 { 5513 struct btrfs_iget_args *args = p; 5514 inode->i_ino = args->location->objectid; 5515 memcpy(&BTRFS_I(inode)->location, args->location, 5516 sizeof(*args->location)); 5517 BTRFS_I(inode)->root = args->root; 5518 return 0; 5519 } 5520 5521 static int btrfs_find_actor(struct inode *inode, void *opaque) 5522 { 5523 struct btrfs_iget_args *args = opaque; 5524 return args->location->objectid == BTRFS_I(inode)->location.objectid && 5525 args->root == BTRFS_I(inode)->root; 5526 } 5527 5528 static struct inode *btrfs_iget_locked(struct super_block *s, 5529 struct btrfs_key *location, 5530 struct btrfs_root *root) 5531 { 5532 struct inode *inode; 5533 struct btrfs_iget_args args; 5534 unsigned long hashval = btrfs_inode_hash(location->objectid, root); 5535 5536 args.location = location; 5537 args.root = root; 5538 5539 inode = iget5_locked(s, hashval, btrfs_find_actor, 5540 btrfs_init_locked_inode, 5541 (void *)&args); 5542 return inode; 5543 } 5544 5545 /* Get an inode object given its location and corresponding root. 5546 * Returns in *is_new if the inode was read from disk 5547 */ 5548 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 5549 struct btrfs_root *root, int *new) 5550 { 5551 struct inode *inode; 5552 5553 inode = btrfs_iget_locked(s, location, root); 5554 if (!inode) 5555 return ERR_PTR(-ENOMEM); 5556 5557 if (inode->i_state & I_NEW) { 5558 btrfs_read_locked_inode(inode); 5559 if (!is_bad_inode(inode)) { 5560 inode_tree_add(inode); 5561 unlock_new_inode(inode); 5562 if (new) 5563 *new = 1; 5564 } else { 5565 unlock_new_inode(inode); 5566 iput(inode); 5567 inode = ERR_PTR(-ESTALE); 5568 } 5569 } 5570 5571 return inode; 5572 } 5573 5574 static struct inode *new_simple_dir(struct super_block *s, 5575 struct btrfs_key *key, 5576 struct btrfs_root *root) 5577 { 5578 struct inode *inode = new_inode(s); 5579 5580 if (!inode) 5581 return ERR_PTR(-ENOMEM); 5582 5583 BTRFS_I(inode)->root = root; 5584 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 5585 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 5586 5587 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 5588 inode->i_op = &btrfs_dir_ro_inode_operations; 5589 inode->i_fop = &simple_dir_operations; 5590 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 5591 inode->i_mtime = CURRENT_TIME; 5592 inode->i_atime = inode->i_mtime; 5593 inode->i_ctime = inode->i_mtime; 5594 BTRFS_I(inode)->i_otime = inode->i_mtime; 5595 5596 return inode; 5597 } 5598 5599 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 5600 { 5601 struct inode *inode; 5602 struct btrfs_root *root = BTRFS_I(dir)->root; 5603 struct btrfs_root *sub_root = root; 5604 struct btrfs_key location; 5605 int index; 5606 int ret = 0; 5607 5608 if (dentry->d_name.len > BTRFS_NAME_LEN) 5609 return ERR_PTR(-ENAMETOOLONG); 5610 5611 ret = btrfs_inode_by_name(dir, dentry, &location); 5612 if (ret < 0) 5613 return ERR_PTR(ret); 5614 5615 if (location.objectid == 0) 5616 return ERR_PTR(-ENOENT); 5617 5618 if (location.type == BTRFS_INODE_ITEM_KEY) { 5619 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 5620 return inode; 5621 } 5622 5623 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 5624 5625 index = srcu_read_lock(&root->fs_info->subvol_srcu); 5626 ret = fixup_tree_root_location(root, dir, dentry, 5627 &location, &sub_root); 5628 if (ret < 0) { 5629 if (ret != -ENOENT) 5630 inode = ERR_PTR(ret); 5631 else 5632 inode = new_simple_dir(dir->i_sb, &location, sub_root); 5633 } else { 5634 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 5635 } 5636 srcu_read_unlock(&root->fs_info->subvol_srcu, index); 5637 5638 if (!IS_ERR(inode) && root != sub_root) { 5639 down_read(&root->fs_info->cleanup_work_sem); 5640 if (!(inode->i_sb->s_flags & MS_RDONLY)) 5641 ret = btrfs_orphan_cleanup(sub_root); 5642 up_read(&root->fs_info->cleanup_work_sem); 5643 if (ret) { 5644 iput(inode); 5645 inode = ERR_PTR(ret); 5646 } 5647 } 5648 5649 return inode; 5650 } 5651 5652 static int btrfs_dentry_delete(const struct dentry *dentry) 5653 { 5654 struct btrfs_root *root; 5655 struct inode *inode = d_inode(dentry); 5656 5657 if (!inode && !IS_ROOT(dentry)) 5658 inode = d_inode(dentry->d_parent); 5659 5660 if (inode) { 5661 root = BTRFS_I(inode)->root; 5662 if (btrfs_root_refs(&root->root_item) == 0) 5663 return 1; 5664 5665 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 5666 return 1; 5667 } 5668 return 0; 5669 } 5670 5671 static void btrfs_dentry_release(struct dentry *dentry) 5672 { 5673 kfree(dentry->d_fsdata); 5674 } 5675 5676 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5677 unsigned int flags) 5678 { 5679 struct inode *inode; 5680 5681 inode = btrfs_lookup_dentry(dir, dentry); 5682 if (IS_ERR(inode)) { 5683 if (PTR_ERR(inode) == -ENOENT) 5684 inode = NULL; 5685 else 5686 return ERR_CAST(inode); 5687 } 5688 5689 return d_splice_alias(inode, dentry); 5690 } 5691 5692 unsigned char btrfs_filetype_table[] = { 5693 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5694 }; 5695 5696 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) 5697 { 5698 struct inode *inode = file_inode(file); 5699 struct btrfs_root *root = BTRFS_I(inode)->root; 5700 struct btrfs_item *item; 5701 struct btrfs_dir_item *di; 5702 struct btrfs_key key; 5703 struct btrfs_key found_key; 5704 struct btrfs_path *path; 5705 struct list_head ins_list; 5706 struct list_head del_list; 5707 int ret; 5708 struct extent_buffer *leaf; 5709 int slot; 5710 unsigned char d_type; 5711 int over = 0; 5712 u32 di_cur; 5713 u32 di_total; 5714 u32 di_len; 5715 int key_type = BTRFS_DIR_INDEX_KEY; 5716 char tmp_name[32]; 5717 char *name_ptr; 5718 int name_len; 5719 int is_curr = 0; /* ctx->pos points to the current index? */ 5720 5721 /* FIXME, use a real flag for deciding about the key type */ 5722 if (root->fs_info->tree_root == root) 5723 key_type = BTRFS_DIR_ITEM_KEY; 5724 5725 if (!dir_emit_dots(file, ctx)) 5726 return 0; 5727 5728 path = btrfs_alloc_path(); 5729 if (!path) 5730 return -ENOMEM; 5731 5732 path->reada = READA_FORWARD; 5733 5734 if (key_type == BTRFS_DIR_INDEX_KEY) { 5735 INIT_LIST_HEAD(&ins_list); 5736 INIT_LIST_HEAD(&del_list); 5737 btrfs_get_delayed_items(inode, &ins_list, &del_list); 5738 } 5739 5740 key.type = key_type; 5741 key.offset = ctx->pos; 5742 key.objectid = btrfs_ino(inode); 5743 5744 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5745 if (ret < 0) 5746 goto err; 5747 5748 while (1) { 5749 leaf = path->nodes[0]; 5750 slot = path->slots[0]; 5751 if (slot >= btrfs_header_nritems(leaf)) { 5752 ret = btrfs_next_leaf(root, path); 5753 if (ret < 0) 5754 goto err; 5755 else if (ret > 0) 5756 break; 5757 continue; 5758 } 5759 5760 item = btrfs_item_nr(slot); 5761 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5762 5763 if (found_key.objectid != key.objectid) 5764 break; 5765 if (found_key.type != key_type) 5766 break; 5767 if (found_key.offset < ctx->pos) 5768 goto next; 5769 if (key_type == BTRFS_DIR_INDEX_KEY && 5770 btrfs_should_delete_dir_index(&del_list, 5771 found_key.offset)) 5772 goto next; 5773 5774 ctx->pos = found_key.offset; 5775 is_curr = 1; 5776 5777 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5778 di_cur = 0; 5779 di_total = btrfs_item_size(leaf, item); 5780 5781 while (di_cur < di_total) { 5782 struct btrfs_key location; 5783 5784 if (verify_dir_item(root, leaf, di)) 5785 break; 5786 5787 name_len = btrfs_dir_name_len(leaf, di); 5788 if (name_len <= sizeof(tmp_name)) { 5789 name_ptr = tmp_name; 5790 } else { 5791 name_ptr = kmalloc(name_len, GFP_NOFS); 5792 if (!name_ptr) { 5793 ret = -ENOMEM; 5794 goto err; 5795 } 5796 } 5797 read_extent_buffer(leaf, name_ptr, 5798 (unsigned long)(di + 1), name_len); 5799 5800 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5801 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5802 5803 5804 /* is this a reference to our own snapshot? If so 5805 * skip it. 5806 * 5807 * In contrast to old kernels, we insert the snapshot's 5808 * dir item and dir index after it has been created, so 5809 * we won't find a reference to our own snapshot. We 5810 * still keep the following code for backward 5811 * compatibility. 5812 */ 5813 if (location.type == BTRFS_ROOT_ITEM_KEY && 5814 location.objectid == root->root_key.objectid) { 5815 over = 0; 5816 goto skip; 5817 } 5818 over = !dir_emit(ctx, name_ptr, name_len, 5819 location.objectid, d_type); 5820 5821 skip: 5822 if (name_ptr != tmp_name) 5823 kfree(name_ptr); 5824 5825 if (over) 5826 goto nopos; 5827 di_len = btrfs_dir_name_len(leaf, di) + 5828 btrfs_dir_data_len(leaf, di) + sizeof(*di); 5829 di_cur += di_len; 5830 di = (struct btrfs_dir_item *)((char *)di + di_len); 5831 } 5832 next: 5833 path->slots[0]++; 5834 } 5835 5836 if (key_type == BTRFS_DIR_INDEX_KEY) { 5837 if (is_curr) 5838 ctx->pos++; 5839 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); 5840 if (ret) 5841 goto nopos; 5842 } 5843 5844 /* Reached end of directory/root. Bump pos past the last item. */ 5845 ctx->pos++; 5846 5847 /* 5848 * Stop new entries from being returned after we return the last 5849 * entry. 5850 * 5851 * New directory entries are assigned a strictly increasing 5852 * offset. This means that new entries created during readdir 5853 * are *guaranteed* to be seen in the future by that readdir. 5854 * This has broken buggy programs which operate on names as 5855 * they're returned by readdir. Until we re-use freed offsets 5856 * we have this hack to stop new entries from being returned 5857 * under the assumption that they'll never reach this huge 5858 * offset. 5859 * 5860 * This is being careful not to overflow 32bit loff_t unless the 5861 * last entry requires it because doing so has broken 32bit apps 5862 * in the past. 5863 */ 5864 if (key_type == BTRFS_DIR_INDEX_KEY) { 5865 if (ctx->pos >= INT_MAX) 5866 ctx->pos = LLONG_MAX; 5867 else 5868 ctx->pos = INT_MAX; 5869 } 5870 nopos: 5871 ret = 0; 5872 err: 5873 if (key_type == BTRFS_DIR_INDEX_KEY) 5874 btrfs_put_delayed_items(&ins_list, &del_list); 5875 btrfs_free_path(path); 5876 return ret; 5877 } 5878 5879 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5880 { 5881 struct btrfs_root *root = BTRFS_I(inode)->root; 5882 struct btrfs_trans_handle *trans; 5883 int ret = 0; 5884 bool nolock = false; 5885 5886 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5887 return 0; 5888 5889 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) 5890 nolock = true; 5891 5892 if (wbc->sync_mode == WB_SYNC_ALL) { 5893 if (nolock) 5894 trans = btrfs_join_transaction_nolock(root); 5895 else 5896 trans = btrfs_join_transaction(root); 5897 if (IS_ERR(trans)) 5898 return PTR_ERR(trans); 5899 ret = btrfs_commit_transaction(trans, root); 5900 } 5901 return ret; 5902 } 5903 5904 /* 5905 * This is somewhat expensive, updating the tree every time the 5906 * inode changes. But, it is most likely to find the inode in cache. 5907 * FIXME, needs more benchmarking...there are no reasons other than performance 5908 * to keep or drop this code. 5909 */ 5910 static int btrfs_dirty_inode(struct inode *inode) 5911 { 5912 struct btrfs_root *root = BTRFS_I(inode)->root; 5913 struct btrfs_trans_handle *trans; 5914 int ret; 5915 5916 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5917 return 0; 5918 5919 trans = btrfs_join_transaction(root); 5920 if (IS_ERR(trans)) 5921 return PTR_ERR(trans); 5922 5923 ret = btrfs_update_inode(trans, root, inode); 5924 if (ret && ret == -ENOSPC) { 5925 /* whoops, lets try again with the full transaction */ 5926 btrfs_end_transaction(trans, root); 5927 trans = btrfs_start_transaction(root, 1); 5928 if (IS_ERR(trans)) 5929 return PTR_ERR(trans); 5930 5931 ret = btrfs_update_inode(trans, root, inode); 5932 } 5933 btrfs_end_transaction(trans, root); 5934 if (BTRFS_I(inode)->delayed_node) 5935 btrfs_balance_delayed_items(root); 5936 5937 return ret; 5938 } 5939 5940 /* 5941 * This is a copy of file_update_time. We need this so we can return error on 5942 * ENOSPC for updating the inode in the case of file write and mmap writes. 5943 */ 5944 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5945 int flags) 5946 { 5947 struct btrfs_root *root = BTRFS_I(inode)->root; 5948 5949 if (btrfs_root_readonly(root)) 5950 return -EROFS; 5951 5952 if (flags & S_VERSION) 5953 inode_inc_iversion(inode); 5954 if (flags & S_CTIME) 5955 inode->i_ctime = *now; 5956 if (flags & S_MTIME) 5957 inode->i_mtime = *now; 5958 if (flags & S_ATIME) 5959 inode->i_atime = *now; 5960 return btrfs_dirty_inode(inode); 5961 } 5962 5963 /* 5964 * find the highest existing sequence number in a directory 5965 * and then set the in-memory index_cnt variable to reflect 5966 * free sequence numbers 5967 */ 5968 static int btrfs_set_inode_index_count(struct inode *inode) 5969 { 5970 struct btrfs_root *root = BTRFS_I(inode)->root; 5971 struct btrfs_key key, found_key; 5972 struct btrfs_path *path; 5973 struct extent_buffer *leaf; 5974 int ret; 5975 5976 key.objectid = btrfs_ino(inode); 5977 key.type = BTRFS_DIR_INDEX_KEY; 5978 key.offset = (u64)-1; 5979 5980 path = btrfs_alloc_path(); 5981 if (!path) 5982 return -ENOMEM; 5983 5984 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5985 if (ret < 0) 5986 goto out; 5987 /* FIXME: we should be able to handle this */ 5988 if (ret == 0) 5989 goto out; 5990 ret = 0; 5991 5992 /* 5993 * MAGIC NUMBER EXPLANATION: 5994 * since we search a directory based on f_pos we have to start at 2 5995 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 5996 * else has to start at 2 5997 */ 5998 if (path->slots[0] == 0) { 5999 BTRFS_I(inode)->index_cnt = 2; 6000 goto out; 6001 } 6002 6003 path->slots[0]--; 6004 6005 leaf = path->nodes[0]; 6006 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6007 6008 if (found_key.objectid != btrfs_ino(inode) || 6009 found_key.type != BTRFS_DIR_INDEX_KEY) { 6010 BTRFS_I(inode)->index_cnt = 2; 6011 goto out; 6012 } 6013 6014 BTRFS_I(inode)->index_cnt = found_key.offset + 1; 6015 out: 6016 btrfs_free_path(path); 6017 return ret; 6018 } 6019 6020 /* 6021 * helper to find a free sequence number in a given directory. This current 6022 * code is very simple, later versions will do smarter things in the btree 6023 */ 6024 int btrfs_set_inode_index(struct inode *dir, u64 *index) 6025 { 6026 int ret = 0; 6027 6028 if (BTRFS_I(dir)->index_cnt == (u64)-1) { 6029 ret = btrfs_inode_delayed_dir_index_count(dir); 6030 if (ret) { 6031 ret = btrfs_set_inode_index_count(dir); 6032 if (ret) 6033 return ret; 6034 } 6035 } 6036 6037 *index = BTRFS_I(dir)->index_cnt; 6038 BTRFS_I(dir)->index_cnt++; 6039 6040 return ret; 6041 } 6042 6043 static int btrfs_insert_inode_locked(struct inode *inode) 6044 { 6045 struct btrfs_iget_args args; 6046 args.location = &BTRFS_I(inode)->location; 6047 args.root = BTRFS_I(inode)->root; 6048 6049 return insert_inode_locked4(inode, 6050 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root), 6051 btrfs_find_actor, &args); 6052 } 6053 6054 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 6055 struct btrfs_root *root, 6056 struct inode *dir, 6057 const char *name, int name_len, 6058 u64 ref_objectid, u64 objectid, 6059 umode_t mode, u64 *index) 6060 { 6061 struct inode *inode; 6062 struct btrfs_inode_item *inode_item; 6063 struct btrfs_key *location; 6064 struct btrfs_path *path; 6065 struct btrfs_inode_ref *ref; 6066 struct btrfs_key key[2]; 6067 u32 sizes[2]; 6068 int nitems = name ? 2 : 1; 6069 unsigned long ptr; 6070 int ret; 6071 6072 path = btrfs_alloc_path(); 6073 if (!path) 6074 return ERR_PTR(-ENOMEM); 6075 6076 inode = new_inode(root->fs_info->sb); 6077 if (!inode) { 6078 btrfs_free_path(path); 6079 return ERR_PTR(-ENOMEM); 6080 } 6081 6082 /* 6083 * O_TMPFILE, set link count to 0, so that after this point, 6084 * we fill in an inode item with the correct link count. 6085 */ 6086 if (!name) 6087 set_nlink(inode, 0); 6088 6089 /* 6090 * we have to initialize this early, so we can reclaim the inode 6091 * number if we fail afterwards in this function. 6092 */ 6093 inode->i_ino = objectid; 6094 6095 if (dir && name) { 6096 trace_btrfs_inode_request(dir); 6097 6098 ret = btrfs_set_inode_index(dir, index); 6099 if (ret) { 6100 btrfs_free_path(path); 6101 iput(inode); 6102 return ERR_PTR(ret); 6103 } 6104 } else if (dir) { 6105 *index = 0; 6106 } 6107 /* 6108 * index_cnt is ignored for everything but a dir, 6109 * btrfs_get_inode_index_count has an explanation for the magic 6110 * number 6111 */ 6112 BTRFS_I(inode)->index_cnt = 2; 6113 BTRFS_I(inode)->dir_index = *index; 6114 BTRFS_I(inode)->root = root; 6115 BTRFS_I(inode)->generation = trans->transid; 6116 inode->i_generation = BTRFS_I(inode)->generation; 6117 6118 /* 6119 * We could have gotten an inode number from somebody who was fsynced 6120 * and then removed in this same transaction, so let's just set full 6121 * sync since it will be a full sync anyway and this will blow away the 6122 * old info in the log. 6123 */ 6124 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 6125 6126 key[0].objectid = objectid; 6127 key[0].type = BTRFS_INODE_ITEM_KEY; 6128 key[0].offset = 0; 6129 6130 sizes[0] = sizeof(struct btrfs_inode_item); 6131 6132 if (name) { 6133 /* 6134 * Start new inodes with an inode_ref. This is slightly more 6135 * efficient for small numbers of hard links since they will 6136 * be packed into one item. Extended refs will kick in if we 6137 * add more hard links than can fit in the ref item. 6138 */ 6139 key[1].objectid = objectid; 6140 key[1].type = BTRFS_INODE_REF_KEY; 6141 key[1].offset = ref_objectid; 6142 6143 sizes[1] = name_len + sizeof(*ref); 6144 } 6145 6146 location = &BTRFS_I(inode)->location; 6147 location->objectid = objectid; 6148 location->offset = 0; 6149 location->type = BTRFS_INODE_ITEM_KEY; 6150 6151 ret = btrfs_insert_inode_locked(inode); 6152 if (ret < 0) 6153 goto fail; 6154 6155 path->leave_spinning = 1; 6156 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems); 6157 if (ret != 0) 6158 goto fail_unlock; 6159 6160 inode_init_owner(inode, dir, mode); 6161 inode_set_bytes(inode, 0); 6162 6163 inode->i_mtime = CURRENT_TIME; 6164 inode->i_atime = inode->i_mtime; 6165 inode->i_ctime = inode->i_mtime; 6166 BTRFS_I(inode)->i_otime = inode->i_mtime; 6167 6168 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 6169 struct btrfs_inode_item); 6170 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, 6171 sizeof(*inode_item)); 6172 fill_inode_item(trans, path->nodes[0], inode_item, inode); 6173 6174 if (name) { 6175 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 6176 struct btrfs_inode_ref); 6177 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 6178 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 6179 ptr = (unsigned long)(ref + 1); 6180 write_extent_buffer(path->nodes[0], name, ptr, name_len); 6181 } 6182 6183 btrfs_mark_buffer_dirty(path->nodes[0]); 6184 btrfs_free_path(path); 6185 6186 btrfs_inherit_iflags(inode, dir); 6187 6188 if (S_ISREG(mode)) { 6189 if (btrfs_test_opt(root, NODATASUM)) 6190 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 6191 if (btrfs_test_opt(root, NODATACOW)) 6192 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 6193 BTRFS_INODE_NODATASUM; 6194 } 6195 6196 inode_tree_add(inode); 6197 6198 trace_btrfs_inode_new(inode); 6199 btrfs_set_inode_last_trans(trans, inode); 6200 6201 btrfs_update_root_times(trans, root); 6202 6203 ret = btrfs_inode_inherit_props(trans, inode, dir); 6204 if (ret) 6205 btrfs_err(root->fs_info, 6206 "error inheriting props for ino %llu (root %llu): %d", 6207 btrfs_ino(inode), root->root_key.objectid, ret); 6208 6209 return inode; 6210 6211 fail_unlock: 6212 unlock_new_inode(inode); 6213 fail: 6214 if (dir && name) 6215 BTRFS_I(dir)->index_cnt--; 6216 btrfs_free_path(path); 6217 iput(inode); 6218 return ERR_PTR(ret); 6219 } 6220 6221 static inline u8 btrfs_inode_type(struct inode *inode) 6222 { 6223 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 6224 } 6225 6226 /* 6227 * utility function to add 'inode' into 'parent_inode' with 6228 * a give name and a given sequence number. 6229 * if 'add_backref' is true, also insert a backref from the 6230 * inode to the parent directory. 6231 */ 6232 int btrfs_add_link(struct btrfs_trans_handle *trans, 6233 struct inode *parent_inode, struct inode *inode, 6234 const char *name, int name_len, int add_backref, u64 index) 6235 { 6236 int ret = 0; 6237 struct btrfs_key key; 6238 struct btrfs_root *root = BTRFS_I(parent_inode)->root; 6239 u64 ino = btrfs_ino(inode); 6240 u64 parent_ino = btrfs_ino(parent_inode); 6241 6242 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6243 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); 6244 } else { 6245 key.objectid = ino; 6246 key.type = BTRFS_INODE_ITEM_KEY; 6247 key.offset = 0; 6248 } 6249 6250 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6251 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 6252 key.objectid, root->root_key.objectid, 6253 parent_ino, index, name, name_len); 6254 } else if (add_backref) { 6255 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 6256 parent_ino, index); 6257 } 6258 6259 /* Nothing to clean up yet */ 6260 if (ret) 6261 return ret; 6262 6263 ret = btrfs_insert_dir_item(trans, root, name, name_len, 6264 parent_inode, &key, 6265 btrfs_inode_type(inode), index); 6266 if (ret == -EEXIST || ret == -EOVERFLOW) 6267 goto fail_dir_item; 6268 else if (ret) { 6269 btrfs_abort_transaction(trans, root, ret); 6270 return ret; 6271 } 6272 6273 btrfs_i_size_write(parent_inode, parent_inode->i_size + 6274 name_len * 2); 6275 inode_inc_iversion(parent_inode); 6276 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 6277 ret = btrfs_update_inode(trans, root, parent_inode); 6278 if (ret) 6279 btrfs_abort_transaction(trans, root, ret); 6280 return ret; 6281 6282 fail_dir_item: 6283 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6284 u64 local_index; 6285 int err; 6286 err = btrfs_del_root_ref(trans, root->fs_info->tree_root, 6287 key.objectid, root->root_key.objectid, 6288 parent_ino, &local_index, name, name_len); 6289 6290 } else if (add_backref) { 6291 u64 local_index; 6292 int err; 6293 6294 err = btrfs_del_inode_ref(trans, root, name, name_len, 6295 ino, parent_ino, &local_index); 6296 } 6297 return ret; 6298 } 6299 6300 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 6301 struct inode *dir, struct dentry *dentry, 6302 struct inode *inode, int backref, u64 index) 6303 { 6304 int err = btrfs_add_link(trans, dir, inode, 6305 dentry->d_name.name, dentry->d_name.len, 6306 backref, index); 6307 if (err > 0) 6308 err = -EEXIST; 6309 return err; 6310 } 6311 6312 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 6313 umode_t mode, dev_t rdev) 6314 { 6315 struct btrfs_trans_handle *trans; 6316 struct btrfs_root *root = BTRFS_I(dir)->root; 6317 struct inode *inode = NULL; 6318 int err; 6319 int drop_inode = 0; 6320 u64 objectid; 6321 u64 index = 0; 6322 6323 /* 6324 * 2 for inode item and ref 6325 * 2 for dir items 6326 * 1 for xattr if selinux is on 6327 */ 6328 trans = btrfs_start_transaction(root, 5); 6329 if (IS_ERR(trans)) 6330 return PTR_ERR(trans); 6331 6332 err = btrfs_find_free_ino(root, &objectid); 6333 if (err) 6334 goto out_unlock; 6335 6336 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6337 dentry->d_name.len, btrfs_ino(dir), objectid, 6338 mode, &index); 6339 if (IS_ERR(inode)) { 6340 err = PTR_ERR(inode); 6341 goto out_unlock; 6342 } 6343 6344 /* 6345 * If the active LSM wants to access the inode during 6346 * d_instantiate it needs these. Smack checks to see 6347 * if the filesystem supports xattrs by looking at the 6348 * ops vector. 6349 */ 6350 inode->i_op = &btrfs_special_inode_operations; 6351 init_special_inode(inode, inode->i_mode, rdev); 6352 6353 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6354 if (err) 6355 goto out_unlock_inode; 6356 6357 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 6358 if (err) { 6359 goto out_unlock_inode; 6360 } else { 6361 btrfs_update_inode(trans, root, inode); 6362 unlock_new_inode(inode); 6363 d_instantiate(dentry, inode); 6364 } 6365 6366 out_unlock: 6367 btrfs_end_transaction(trans, root); 6368 btrfs_balance_delayed_items(root); 6369 btrfs_btree_balance_dirty(root); 6370 if (drop_inode) { 6371 inode_dec_link_count(inode); 6372 iput(inode); 6373 } 6374 return err; 6375 6376 out_unlock_inode: 6377 drop_inode = 1; 6378 unlock_new_inode(inode); 6379 goto out_unlock; 6380 6381 } 6382 6383 static int btrfs_create(struct inode *dir, struct dentry *dentry, 6384 umode_t mode, bool excl) 6385 { 6386 struct btrfs_trans_handle *trans; 6387 struct btrfs_root *root = BTRFS_I(dir)->root; 6388 struct inode *inode = NULL; 6389 int drop_inode_on_err = 0; 6390 int err; 6391 u64 objectid; 6392 u64 index = 0; 6393 6394 /* 6395 * 2 for inode item and ref 6396 * 2 for dir items 6397 * 1 for xattr if selinux is on 6398 */ 6399 trans = btrfs_start_transaction(root, 5); 6400 if (IS_ERR(trans)) 6401 return PTR_ERR(trans); 6402 6403 err = btrfs_find_free_ino(root, &objectid); 6404 if (err) 6405 goto out_unlock; 6406 6407 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6408 dentry->d_name.len, btrfs_ino(dir), objectid, 6409 mode, &index); 6410 if (IS_ERR(inode)) { 6411 err = PTR_ERR(inode); 6412 goto out_unlock; 6413 } 6414 drop_inode_on_err = 1; 6415 /* 6416 * If the active LSM wants to access the inode during 6417 * d_instantiate it needs these. Smack checks to see 6418 * if the filesystem supports xattrs by looking at the 6419 * ops vector. 6420 */ 6421 inode->i_fop = &btrfs_file_operations; 6422 inode->i_op = &btrfs_file_inode_operations; 6423 inode->i_mapping->a_ops = &btrfs_aops; 6424 6425 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6426 if (err) 6427 goto out_unlock_inode; 6428 6429 err = btrfs_update_inode(trans, root, inode); 6430 if (err) 6431 goto out_unlock_inode; 6432 6433 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 6434 if (err) 6435 goto out_unlock_inode; 6436 6437 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 6438 unlock_new_inode(inode); 6439 d_instantiate(dentry, inode); 6440 6441 out_unlock: 6442 btrfs_end_transaction(trans, root); 6443 if (err && drop_inode_on_err) { 6444 inode_dec_link_count(inode); 6445 iput(inode); 6446 } 6447 btrfs_balance_delayed_items(root); 6448 btrfs_btree_balance_dirty(root); 6449 return err; 6450 6451 out_unlock_inode: 6452 unlock_new_inode(inode); 6453 goto out_unlock; 6454 6455 } 6456 6457 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 6458 struct dentry *dentry) 6459 { 6460 struct btrfs_trans_handle *trans = NULL; 6461 struct btrfs_root *root = BTRFS_I(dir)->root; 6462 struct inode *inode = d_inode(old_dentry); 6463 u64 index; 6464 int err; 6465 int drop_inode = 0; 6466 6467 /* do not allow sys_link's with other subvols of the same device */ 6468 if (root->objectid != BTRFS_I(inode)->root->objectid) 6469 return -EXDEV; 6470 6471 if (inode->i_nlink >= BTRFS_LINK_MAX) 6472 return -EMLINK; 6473 6474 err = btrfs_set_inode_index(dir, &index); 6475 if (err) 6476 goto fail; 6477 6478 /* 6479 * 2 items for inode and inode ref 6480 * 2 items for dir items 6481 * 1 item for parent inode 6482 */ 6483 trans = btrfs_start_transaction(root, 5); 6484 if (IS_ERR(trans)) { 6485 err = PTR_ERR(trans); 6486 trans = NULL; 6487 goto fail; 6488 } 6489 6490 /* There are several dir indexes for this inode, clear the cache. */ 6491 BTRFS_I(inode)->dir_index = 0ULL; 6492 inc_nlink(inode); 6493 inode_inc_iversion(inode); 6494 inode->i_ctime = CURRENT_TIME; 6495 ihold(inode); 6496 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 6497 6498 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); 6499 6500 if (err) { 6501 drop_inode = 1; 6502 } else { 6503 struct dentry *parent = dentry->d_parent; 6504 err = btrfs_update_inode(trans, root, inode); 6505 if (err) 6506 goto fail; 6507 if (inode->i_nlink == 1) { 6508 /* 6509 * If new hard link count is 1, it's a file created 6510 * with open(2) O_TMPFILE flag. 6511 */ 6512 err = btrfs_orphan_del(trans, inode); 6513 if (err) 6514 goto fail; 6515 } 6516 d_instantiate(dentry, inode); 6517 btrfs_log_new_name(trans, inode, NULL, parent); 6518 } 6519 6520 btrfs_balance_delayed_items(root); 6521 fail: 6522 if (trans) 6523 btrfs_end_transaction(trans, root); 6524 if (drop_inode) { 6525 inode_dec_link_count(inode); 6526 iput(inode); 6527 } 6528 btrfs_btree_balance_dirty(root); 6529 return err; 6530 } 6531 6532 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 6533 { 6534 struct inode *inode = NULL; 6535 struct btrfs_trans_handle *trans; 6536 struct btrfs_root *root = BTRFS_I(dir)->root; 6537 int err = 0; 6538 int drop_on_err = 0; 6539 u64 objectid = 0; 6540 u64 index = 0; 6541 6542 /* 6543 * 2 items for inode and ref 6544 * 2 items for dir items 6545 * 1 for xattr if selinux is on 6546 */ 6547 trans = btrfs_start_transaction(root, 5); 6548 if (IS_ERR(trans)) 6549 return PTR_ERR(trans); 6550 6551 err = btrfs_find_free_ino(root, &objectid); 6552 if (err) 6553 goto out_fail; 6554 6555 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6556 dentry->d_name.len, btrfs_ino(dir), objectid, 6557 S_IFDIR | mode, &index); 6558 if (IS_ERR(inode)) { 6559 err = PTR_ERR(inode); 6560 goto out_fail; 6561 } 6562 6563 drop_on_err = 1; 6564 /* these must be set before we unlock the inode */ 6565 inode->i_op = &btrfs_dir_inode_operations; 6566 inode->i_fop = &btrfs_dir_file_operations; 6567 6568 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6569 if (err) 6570 goto out_fail_inode; 6571 6572 btrfs_i_size_write(inode, 0); 6573 err = btrfs_update_inode(trans, root, inode); 6574 if (err) 6575 goto out_fail_inode; 6576 6577 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, 6578 dentry->d_name.len, 0, index); 6579 if (err) 6580 goto out_fail_inode; 6581 6582 d_instantiate(dentry, inode); 6583 /* 6584 * mkdir is special. We're unlocking after we call d_instantiate 6585 * to avoid a race with nfsd calling d_instantiate. 6586 */ 6587 unlock_new_inode(inode); 6588 drop_on_err = 0; 6589 6590 out_fail: 6591 btrfs_end_transaction(trans, root); 6592 if (drop_on_err) { 6593 inode_dec_link_count(inode); 6594 iput(inode); 6595 } 6596 btrfs_balance_delayed_items(root); 6597 btrfs_btree_balance_dirty(root); 6598 return err; 6599 6600 out_fail_inode: 6601 unlock_new_inode(inode); 6602 goto out_fail; 6603 } 6604 6605 /* Find next extent map of a given extent map, caller needs to ensure locks */ 6606 static struct extent_map *next_extent_map(struct extent_map *em) 6607 { 6608 struct rb_node *next; 6609 6610 next = rb_next(&em->rb_node); 6611 if (!next) 6612 return NULL; 6613 return container_of(next, struct extent_map, rb_node); 6614 } 6615 6616 static struct extent_map *prev_extent_map(struct extent_map *em) 6617 { 6618 struct rb_node *prev; 6619 6620 prev = rb_prev(&em->rb_node); 6621 if (!prev) 6622 return NULL; 6623 return container_of(prev, struct extent_map, rb_node); 6624 } 6625 6626 /* helper for btfs_get_extent. Given an existing extent in the tree, 6627 * the existing extent is the nearest extent to map_start, 6628 * and an extent that you want to insert, deal with overlap and insert 6629 * the best fitted new extent into the tree. 6630 */ 6631 static int merge_extent_mapping(struct extent_map_tree *em_tree, 6632 struct extent_map *existing, 6633 struct extent_map *em, 6634 u64 map_start) 6635 { 6636 struct extent_map *prev; 6637 struct extent_map *next; 6638 u64 start; 6639 u64 end; 6640 u64 start_diff; 6641 6642 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 6643 6644 if (existing->start > map_start) { 6645 next = existing; 6646 prev = prev_extent_map(next); 6647 } else { 6648 prev = existing; 6649 next = next_extent_map(prev); 6650 } 6651 6652 start = prev ? extent_map_end(prev) : em->start; 6653 start = max_t(u64, start, em->start); 6654 end = next ? next->start : extent_map_end(em); 6655 end = min_t(u64, end, extent_map_end(em)); 6656 start_diff = start - em->start; 6657 em->start = start; 6658 em->len = end - start; 6659 if (em->block_start < EXTENT_MAP_LAST_BYTE && 6660 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 6661 em->block_start += start_diff; 6662 em->block_len -= start_diff; 6663 } 6664 return add_extent_mapping(em_tree, em, 0); 6665 } 6666 6667 static noinline int uncompress_inline(struct btrfs_path *path, 6668 struct page *page, 6669 size_t pg_offset, u64 extent_offset, 6670 struct btrfs_file_extent_item *item) 6671 { 6672 int ret; 6673 struct extent_buffer *leaf = path->nodes[0]; 6674 char *tmp; 6675 size_t max_size; 6676 unsigned long inline_size; 6677 unsigned long ptr; 6678 int compress_type; 6679 6680 WARN_ON(pg_offset != 0); 6681 compress_type = btrfs_file_extent_compression(leaf, item); 6682 max_size = btrfs_file_extent_ram_bytes(leaf, item); 6683 inline_size = btrfs_file_extent_inline_item_len(leaf, 6684 btrfs_item_nr(path->slots[0])); 6685 tmp = kmalloc(inline_size, GFP_NOFS); 6686 if (!tmp) 6687 return -ENOMEM; 6688 ptr = btrfs_file_extent_inline_start(item); 6689 6690 read_extent_buffer(leaf, tmp, ptr, inline_size); 6691 6692 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); 6693 ret = btrfs_decompress(compress_type, tmp, page, 6694 extent_offset, inline_size, max_size); 6695 kfree(tmp); 6696 return ret; 6697 } 6698 6699 /* 6700 * a bit scary, this does extent mapping from logical file offset to the disk. 6701 * the ugly parts come from merging extents from the disk with the in-ram 6702 * representation. This gets more complex because of the data=ordered code, 6703 * where the in-ram extents might be locked pending data=ordered completion. 6704 * 6705 * This also copies inline extents directly into the page. 6706 */ 6707 6708 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 6709 size_t pg_offset, u64 start, u64 len, 6710 int create) 6711 { 6712 int ret; 6713 int err = 0; 6714 u64 extent_start = 0; 6715 u64 extent_end = 0; 6716 u64 objectid = btrfs_ino(inode); 6717 u32 found_type; 6718 struct btrfs_path *path = NULL; 6719 struct btrfs_root *root = BTRFS_I(inode)->root; 6720 struct btrfs_file_extent_item *item; 6721 struct extent_buffer *leaf; 6722 struct btrfs_key found_key; 6723 struct extent_map *em = NULL; 6724 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 6725 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 6726 struct btrfs_trans_handle *trans = NULL; 6727 const bool new_inline = !page || create; 6728 6729 again: 6730 read_lock(&em_tree->lock); 6731 em = lookup_extent_mapping(em_tree, start, len); 6732 if (em) 6733 em->bdev = root->fs_info->fs_devices->latest_bdev; 6734 read_unlock(&em_tree->lock); 6735 6736 if (em) { 6737 if (em->start > start || em->start + em->len <= start) 6738 free_extent_map(em); 6739 else if (em->block_start == EXTENT_MAP_INLINE && page) 6740 free_extent_map(em); 6741 else 6742 goto out; 6743 } 6744 em = alloc_extent_map(); 6745 if (!em) { 6746 err = -ENOMEM; 6747 goto out; 6748 } 6749 em->bdev = root->fs_info->fs_devices->latest_bdev; 6750 em->start = EXTENT_MAP_HOLE; 6751 em->orig_start = EXTENT_MAP_HOLE; 6752 em->len = (u64)-1; 6753 em->block_len = (u64)-1; 6754 6755 if (!path) { 6756 path = btrfs_alloc_path(); 6757 if (!path) { 6758 err = -ENOMEM; 6759 goto out; 6760 } 6761 /* 6762 * Chances are we'll be called again, so go ahead and do 6763 * readahead 6764 */ 6765 path->reada = READA_FORWARD; 6766 } 6767 6768 ret = btrfs_lookup_file_extent(trans, root, path, 6769 objectid, start, trans != NULL); 6770 if (ret < 0) { 6771 err = ret; 6772 goto out; 6773 } 6774 6775 if (ret != 0) { 6776 if (path->slots[0] == 0) 6777 goto not_found; 6778 path->slots[0]--; 6779 } 6780 6781 leaf = path->nodes[0]; 6782 item = btrfs_item_ptr(leaf, path->slots[0], 6783 struct btrfs_file_extent_item); 6784 /* are we inside the extent that was found? */ 6785 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6786 found_type = found_key.type; 6787 if (found_key.objectid != objectid || 6788 found_type != BTRFS_EXTENT_DATA_KEY) { 6789 /* 6790 * If we backup past the first extent we want to move forward 6791 * and see if there is an extent in front of us, otherwise we'll 6792 * say there is a hole for our whole search range which can 6793 * cause problems. 6794 */ 6795 extent_end = start; 6796 goto next; 6797 } 6798 6799 found_type = btrfs_file_extent_type(leaf, item); 6800 extent_start = found_key.offset; 6801 if (found_type == BTRFS_FILE_EXTENT_REG || 6802 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6803 extent_end = extent_start + 6804 btrfs_file_extent_num_bytes(leaf, item); 6805 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6806 size_t size; 6807 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6808 extent_end = ALIGN(extent_start + size, root->sectorsize); 6809 } 6810 next: 6811 if (start >= extent_end) { 6812 path->slots[0]++; 6813 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6814 ret = btrfs_next_leaf(root, path); 6815 if (ret < 0) { 6816 err = ret; 6817 goto out; 6818 } 6819 if (ret > 0) 6820 goto not_found; 6821 leaf = path->nodes[0]; 6822 } 6823 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6824 if (found_key.objectid != objectid || 6825 found_key.type != BTRFS_EXTENT_DATA_KEY) 6826 goto not_found; 6827 if (start + len <= found_key.offset) 6828 goto not_found; 6829 if (start > found_key.offset) 6830 goto next; 6831 em->start = start; 6832 em->orig_start = start; 6833 em->len = found_key.offset - start; 6834 goto not_found_em; 6835 } 6836 6837 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em); 6838 6839 if (found_type == BTRFS_FILE_EXTENT_REG || 6840 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6841 goto insert; 6842 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6843 unsigned long ptr; 6844 char *map; 6845 size_t size; 6846 size_t extent_offset; 6847 size_t copy_size; 6848 6849 if (new_inline) 6850 goto out; 6851 6852 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6853 extent_offset = page_offset(page) + pg_offset - extent_start; 6854 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, 6855 size - extent_offset); 6856 em->start = extent_start + extent_offset; 6857 em->len = ALIGN(copy_size, root->sectorsize); 6858 em->orig_block_len = em->len; 6859 em->orig_start = em->start; 6860 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6861 if (create == 0 && !PageUptodate(page)) { 6862 if (btrfs_file_extent_compression(leaf, item) != 6863 BTRFS_COMPRESS_NONE) { 6864 ret = uncompress_inline(path, page, pg_offset, 6865 extent_offset, item); 6866 if (ret) { 6867 err = ret; 6868 goto out; 6869 } 6870 } else { 6871 map = kmap(page); 6872 read_extent_buffer(leaf, map + pg_offset, ptr, 6873 copy_size); 6874 if (pg_offset + copy_size < PAGE_CACHE_SIZE) { 6875 memset(map + pg_offset + copy_size, 0, 6876 PAGE_CACHE_SIZE - pg_offset - 6877 copy_size); 6878 } 6879 kunmap(page); 6880 } 6881 flush_dcache_page(page); 6882 } else if (create && PageUptodate(page)) { 6883 BUG(); 6884 if (!trans) { 6885 kunmap(page); 6886 free_extent_map(em); 6887 em = NULL; 6888 6889 btrfs_release_path(path); 6890 trans = btrfs_join_transaction(root); 6891 6892 if (IS_ERR(trans)) 6893 return ERR_CAST(trans); 6894 goto again; 6895 } 6896 map = kmap(page); 6897 write_extent_buffer(leaf, map + pg_offset, ptr, 6898 copy_size); 6899 kunmap(page); 6900 btrfs_mark_buffer_dirty(leaf); 6901 } 6902 set_extent_uptodate(io_tree, em->start, 6903 extent_map_end(em) - 1, NULL, GFP_NOFS); 6904 goto insert; 6905 } 6906 not_found: 6907 em->start = start; 6908 em->orig_start = start; 6909 em->len = len; 6910 not_found_em: 6911 em->block_start = EXTENT_MAP_HOLE; 6912 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6913 insert: 6914 btrfs_release_path(path); 6915 if (em->start > start || extent_map_end(em) <= start) { 6916 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", 6917 em->start, em->len, start, len); 6918 err = -EIO; 6919 goto out; 6920 } 6921 6922 err = 0; 6923 write_lock(&em_tree->lock); 6924 ret = add_extent_mapping(em_tree, em, 0); 6925 /* it is possible that someone inserted the extent into the tree 6926 * while we had the lock dropped. It is also possible that 6927 * an overlapping map exists in the tree 6928 */ 6929 if (ret == -EEXIST) { 6930 struct extent_map *existing; 6931 6932 ret = 0; 6933 6934 existing = search_extent_mapping(em_tree, start, len); 6935 /* 6936 * existing will always be non-NULL, since there must be 6937 * extent causing the -EEXIST. 6938 */ 6939 if (start >= extent_map_end(existing) || 6940 start <= existing->start) { 6941 /* 6942 * The existing extent map is the one nearest to 6943 * the [start, start + len) range which overlaps 6944 */ 6945 err = merge_extent_mapping(em_tree, existing, 6946 em, start); 6947 free_extent_map(existing); 6948 if (err) { 6949 free_extent_map(em); 6950 em = NULL; 6951 } 6952 } else { 6953 free_extent_map(em); 6954 em = existing; 6955 err = 0; 6956 } 6957 } 6958 write_unlock(&em_tree->lock); 6959 out: 6960 6961 trace_btrfs_get_extent(root, em); 6962 6963 btrfs_free_path(path); 6964 if (trans) { 6965 ret = btrfs_end_transaction(trans, root); 6966 if (!err) 6967 err = ret; 6968 } 6969 if (err) { 6970 free_extent_map(em); 6971 return ERR_PTR(err); 6972 } 6973 BUG_ON(!em); /* Error is always set */ 6974 return em; 6975 } 6976 6977 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, 6978 size_t pg_offset, u64 start, u64 len, 6979 int create) 6980 { 6981 struct extent_map *em; 6982 struct extent_map *hole_em = NULL; 6983 u64 range_start = start; 6984 u64 end; 6985 u64 found; 6986 u64 found_end; 6987 int err = 0; 6988 6989 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 6990 if (IS_ERR(em)) 6991 return em; 6992 if (em) { 6993 /* 6994 * if our em maps to 6995 * - a hole or 6996 * - a pre-alloc extent, 6997 * there might actually be delalloc bytes behind it. 6998 */ 6999 if (em->block_start != EXTENT_MAP_HOLE && 7000 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7001 return em; 7002 else 7003 hole_em = em; 7004 } 7005 7006 /* check to see if we've wrapped (len == -1 or similar) */ 7007 end = start + len; 7008 if (end < start) 7009 end = (u64)-1; 7010 else 7011 end -= 1; 7012 7013 em = NULL; 7014 7015 /* ok, we didn't find anything, lets look for delalloc */ 7016 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, 7017 end, len, EXTENT_DELALLOC, 1); 7018 found_end = range_start + found; 7019 if (found_end < range_start) 7020 found_end = (u64)-1; 7021 7022 /* 7023 * we didn't find anything useful, return 7024 * the original results from get_extent() 7025 */ 7026 if (range_start > end || found_end <= start) { 7027 em = hole_em; 7028 hole_em = NULL; 7029 goto out; 7030 } 7031 7032 /* adjust the range_start to make sure it doesn't 7033 * go backwards from the start they passed in 7034 */ 7035 range_start = max(start, range_start); 7036 found = found_end - range_start; 7037 7038 if (found > 0) { 7039 u64 hole_start = start; 7040 u64 hole_len = len; 7041 7042 em = alloc_extent_map(); 7043 if (!em) { 7044 err = -ENOMEM; 7045 goto out; 7046 } 7047 /* 7048 * when btrfs_get_extent can't find anything it 7049 * returns one huge hole 7050 * 7051 * make sure what it found really fits our range, and 7052 * adjust to make sure it is based on the start from 7053 * the caller 7054 */ 7055 if (hole_em) { 7056 u64 calc_end = extent_map_end(hole_em); 7057 7058 if (calc_end <= start || (hole_em->start > end)) { 7059 free_extent_map(hole_em); 7060 hole_em = NULL; 7061 } else { 7062 hole_start = max(hole_em->start, start); 7063 hole_len = calc_end - hole_start; 7064 } 7065 } 7066 em->bdev = NULL; 7067 if (hole_em && range_start > hole_start) { 7068 /* our hole starts before our delalloc, so we 7069 * have to return just the parts of the hole 7070 * that go until the delalloc starts 7071 */ 7072 em->len = min(hole_len, 7073 range_start - hole_start); 7074 em->start = hole_start; 7075 em->orig_start = hole_start; 7076 /* 7077 * don't adjust block start at all, 7078 * it is fixed at EXTENT_MAP_HOLE 7079 */ 7080 em->block_start = hole_em->block_start; 7081 em->block_len = hole_len; 7082 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 7083 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 7084 } else { 7085 em->start = range_start; 7086 em->len = found; 7087 em->orig_start = range_start; 7088 em->block_start = EXTENT_MAP_DELALLOC; 7089 em->block_len = found; 7090 } 7091 } else if (hole_em) { 7092 return hole_em; 7093 } 7094 out: 7095 7096 free_extent_map(hole_em); 7097 if (err) { 7098 free_extent_map(em); 7099 return ERR_PTR(err); 7100 } 7101 return em; 7102 } 7103 7104 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 7105 u64 start, u64 len) 7106 { 7107 struct btrfs_root *root = BTRFS_I(inode)->root; 7108 struct extent_map *em; 7109 struct btrfs_key ins; 7110 u64 alloc_hint; 7111 int ret; 7112 7113 alloc_hint = get_extent_allocation_hint(inode, start, len); 7114 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0, 7115 alloc_hint, &ins, 1, 1); 7116 if (ret) 7117 return ERR_PTR(ret); 7118 7119 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, 7120 ins.offset, ins.offset, ins.offset, 0); 7121 if (IS_ERR(em)) { 7122 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 7123 return em; 7124 } 7125 7126 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, 7127 ins.offset, ins.offset, 0); 7128 if (ret) { 7129 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 7130 free_extent_map(em); 7131 return ERR_PTR(ret); 7132 } 7133 7134 return em; 7135 } 7136 7137 /* 7138 * returns 1 when the nocow is safe, < 1 on error, 0 if the 7139 * block must be cow'd 7140 */ 7141 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, 7142 u64 *orig_start, u64 *orig_block_len, 7143 u64 *ram_bytes) 7144 { 7145 struct btrfs_trans_handle *trans; 7146 struct btrfs_path *path; 7147 int ret; 7148 struct extent_buffer *leaf; 7149 struct btrfs_root *root = BTRFS_I(inode)->root; 7150 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7151 struct btrfs_file_extent_item *fi; 7152 struct btrfs_key key; 7153 u64 disk_bytenr; 7154 u64 backref_offset; 7155 u64 extent_end; 7156 u64 num_bytes; 7157 int slot; 7158 int found_type; 7159 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); 7160 7161 path = btrfs_alloc_path(); 7162 if (!path) 7163 return -ENOMEM; 7164 7165 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), 7166 offset, 0); 7167 if (ret < 0) 7168 goto out; 7169 7170 slot = path->slots[0]; 7171 if (ret == 1) { 7172 if (slot == 0) { 7173 /* can't find the item, must cow */ 7174 ret = 0; 7175 goto out; 7176 } 7177 slot--; 7178 } 7179 ret = 0; 7180 leaf = path->nodes[0]; 7181 btrfs_item_key_to_cpu(leaf, &key, slot); 7182 if (key.objectid != btrfs_ino(inode) || 7183 key.type != BTRFS_EXTENT_DATA_KEY) { 7184 /* not our file or wrong item type, must cow */ 7185 goto out; 7186 } 7187 7188 if (key.offset > offset) { 7189 /* Wrong offset, must cow */ 7190 goto out; 7191 } 7192 7193 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 7194 found_type = btrfs_file_extent_type(leaf, fi); 7195 if (found_type != BTRFS_FILE_EXTENT_REG && 7196 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 7197 /* not a regular extent, must cow */ 7198 goto out; 7199 } 7200 7201 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) 7202 goto out; 7203 7204 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 7205 if (extent_end <= offset) 7206 goto out; 7207 7208 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 7209 if (disk_bytenr == 0) 7210 goto out; 7211 7212 if (btrfs_file_extent_compression(leaf, fi) || 7213 btrfs_file_extent_encryption(leaf, fi) || 7214 btrfs_file_extent_other_encoding(leaf, fi)) 7215 goto out; 7216 7217 backref_offset = btrfs_file_extent_offset(leaf, fi); 7218 7219 if (orig_start) { 7220 *orig_start = key.offset - backref_offset; 7221 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 7222 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 7223 } 7224 7225 if (btrfs_extent_readonly(root, disk_bytenr)) 7226 goto out; 7227 7228 num_bytes = min(offset + *len, extent_end) - offset; 7229 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { 7230 u64 range_end; 7231 7232 range_end = round_up(offset + num_bytes, root->sectorsize) - 1; 7233 ret = test_range_bit(io_tree, offset, range_end, 7234 EXTENT_DELALLOC, 0, NULL); 7235 if (ret) { 7236 ret = -EAGAIN; 7237 goto out; 7238 } 7239 } 7240 7241 btrfs_release_path(path); 7242 7243 /* 7244 * look for other files referencing this extent, if we 7245 * find any we must cow 7246 */ 7247 trans = btrfs_join_transaction(root); 7248 if (IS_ERR(trans)) { 7249 ret = 0; 7250 goto out; 7251 } 7252 7253 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), 7254 key.offset - backref_offset, disk_bytenr); 7255 btrfs_end_transaction(trans, root); 7256 if (ret) { 7257 ret = 0; 7258 goto out; 7259 } 7260 7261 /* 7262 * adjust disk_bytenr and num_bytes to cover just the bytes 7263 * in this extent we are about to write. If there 7264 * are any csums in that range we have to cow in order 7265 * to keep the csums correct 7266 */ 7267 disk_bytenr += backref_offset; 7268 disk_bytenr += offset - key.offset; 7269 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 7270 goto out; 7271 /* 7272 * all of the above have passed, it is safe to overwrite this extent 7273 * without cow 7274 */ 7275 *len = num_bytes; 7276 ret = 1; 7277 out: 7278 btrfs_free_path(path); 7279 return ret; 7280 } 7281 7282 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end) 7283 { 7284 struct radix_tree_root *root = &inode->i_mapping->page_tree; 7285 int found = false; 7286 void **pagep = NULL; 7287 struct page *page = NULL; 7288 int start_idx; 7289 int end_idx; 7290 7291 start_idx = start >> PAGE_CACHE_SHIFT; 7292 7293 /* 7294 * end is the last byte in the last page. end == start is legal 7295 */ 7296 end_idx = end >> PAGE_CACHE_SHIFT; 7297 7298 rcu_read_lock(); 7299 7300 /* Most of the code in this while loop is lifted from 7301 * find_get_page. It's been modified to begin searching from a 7302 * page and return just the first page found in that range. If the 7303 * found idx is less than or equal to the end idx then we know that 7304 * a page exists. If no pages are found or if those pages are 7305 * outside of the range then we're fine (yay!) */ 7306 while (page == NULL && 7307 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) { 7308 page = radix_tree_deref_slot(pagep); 7309 if (unlikely(!page)) 7310 break; 7311 7312 if (radix_tree_exception(page)) { 7313 if (radix_tree_deref_retry(page)) { 7314 page = NULL; 7315 continue; 7316 } 7317 /* 7318 * Otherwise, shmem/tmpfs must be storing a swap entry 7319 * here as an exceptional entry: so return it without 7320 * attempting to raise page count. 7321 */ 7322 page = NULL; 7323 break; /* TODO: Is this relevant for this use case? */ 7324 } 7325 7326 if (!page_cache_get_speculative(page)) { 7327 page = NULL; 7328 continue; 7329 } 7330 7331 /* 7332 * Has the page moved? 7333 * This is part of the lockless pagecache protocol. See 7334 * include/linux/pagemap.h for details. 7335 */ 7336 if (unlikely(page != *pagep)) { 7337 page_cache_release(page); 7338 page = NULL; 7339 } 7340 } 7341 7342 if (page) { 7343 if (page->index <= end_idx) 7344 found = true; 7345 page_cache_release(page); 7346 } 7347 7348 rcu_read_unlock(); 7349 return found; 7350 } 7351 7352 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 7353 struct extent_state **cached_state, int writing) 7354 { 7355 struct btrfs_ordered_extent *ordered; 7356 int ret = 0; 7357 7358 while (1) { 7359 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7360 cached_state); 7361 /* 7362 * We're concerned with the entire range that we're going to be 7363 * doing DIO to, so we need to make sure theres no ordered 7364 * extents in this range. 7365 */ 7366 ordered = btrfs_lookup_ordered_range(inode, lockstart, 7367 lockend - lockstart + 1); 7368 7369 /* 7370 * We need to make sure there are no buffered pages in this 7371 * range either, we could have raced between the invalidate in 7372 * generic_file_direct_write and locking the extent. The 7373 * invalidate needs to happen so that reads after a write do not 7374 * get stale data. 7375 */ 7376 if (!ordered && 7377 (!writing || 7378 !btrfs_page_exists_in_range(inode, lockstart, lockend))) 7379 break; 7380 7381 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7382 cached_state, GFP_NOFS); 7383 7384 if (ordered) { 7385 btrfs_start_ordered_extent(inode, ordered, 1); 7386 btrfs_put_ordered_extent(ordered); 7387 } else { 7388 /* 7389 * We could trigger writeback for this range (and wait 7390 * for it to complete) and then invalidate the pages for 7391 * this range (through invalidate_inode_pages2_range()), 7392 * but that can lead us to a deadlock with a concurrent 7393 * call to readpages() (a buffered read or a defrag call 7394 * triggered a readahead) on a page lock due to an 7395 * ordered dio extent we created before but did not have 7396 * yet a corresponding bio submitted (whence it can not 7397 * complete), which makes readpages() wait for that 7398 * ordered extent to complete while holding a lock on 7399 * that page. 7400 */ 7401 ret = -ENOTBLK; 7402 break; 7403 } 7404 7405 cond_resched(); 7406 } 7407 7408 return ret; 7409 } 7410 7411 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 7412 u64 len, u64 orig_start, 7413 u64 block_start, u64 block_len, 7414 u64 orig_block_len, u64 ram_bytes, 7415 int type) 7416 { 7417 struct extent_map_tree *em_tree; 7418 struct extent_map *em; 7419 struct btrfs_root *root = BTRFS_I(inode)->root; 7420 int ret; 7421 7422 em_tree = &BTRFS_I(inode)->extent_tree; 7423 em = alloc_extent_map(); 7424 if (!em) 7425 return ERR_PTR(-ENOMEM); 7426 7427 em->start = start; 7428 em->orig_start = orig_start; 7429 em->mod_start = start; 7430 em->mod_len = len; 7431 em->len = len; 7432 em->block_len = block_len; 7433 em->block_start = block_start; 7434 em->bdev = root->fs_info->fs_devices->latest_bdev; 7435 em->orig_block_len = orig_block_len; 7436 em->ram_bytes = ram_bytes; 7437 em->generation = -1; 7438 set_bit(EXTENT_FLAG_PINNED, &em->flags); 7439 if (type == BTRFS_ORDERED_PREALLOC) 7440 set_bit(EXTENT_FLAG_FILLING, &em->flags); 7441 7442 do { 7443 btrfs_drop_extent_cache(inode, em->start, 7444 em->start + em->len - 1, 0); 7445 write_lock(&em_tree->lock); 7446 ret = add_extent_mapping(em_tree, em, 1); 7447 write_unlock(&em_tree->lock); 7448 } while (ret == -EEXIST); 7449 7450 if (ret) { 7451 free_extent_map(em); 7452 return ERR_PTR(ret); 7453 } 7454 7455 return em; 7456 } 7457 7458 static void adjust_dio_outstanding_extents(struct inode *inode, 7459 struct btrfs_dio_data *dio_data, 7460 const u64 len) 7461 { 7462 unsigned num_extents; 7463 7464 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1, 7465 BTRFS_MAX_EXTENT_SIZE); 7466 /* 7467 * If we have an outstanding_extents count still set then we're 7468 * within our reservation, otherwise we need to adjust our inode 7469 * counter appropriately. 7470 */ 7471 if (dio_data->outstanding_extents) { 7472 dio_data->outstanding_extents -= num_extents; 7473 } else { 7474 spin_lock(&BTRFS_I(inode)->lock); 7475 BTRFS_I(inode)->outstanding_extents += num_extents; 7476 spin_unlock(&BTRFS_I(inode)->lock); 7477 } 7478 } 7479 7480 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 7481 struct buffer_head *bh_result, int create) 7482 { 7483 struct extent_map *em; 7484 struct btrfs_root *root = BTRFS_I(inode)->root; 7485 struct extent_state *cached_state = NULL; 7486 struct btrfs_dio_data *dio_data = NULL; 7487 u64 start = iblock << inode->i_blkbits; 7488 u64 lockstart, lockend; 7489 u64 len = bh_result->b_size; 7490 int unlock_bits = EXTENT_LOCKED; 7491 int ret = 0; 7492 7493 if (create) 7494 unlock_bits |= EXTENT_DIRTY; 7495 else 7496 len = min_t(u64, len, root->sectorsize); 7497 7498 lockstart = start; 7499 lockend = start + len - 1; 7500 7501 if (current->journal_info) { 7502 /* 7503 * Need to pull our outstanding extents and set journal_info to NULL so 7504 * that anything that needs to check if there's a transction doesn't get 7505 * confused. 7506 */ 7507 dio_data = current->journal_info; 7508 current->journal_info = NULL; 7509 } 7510 7511 /* 7512 * If this errors out it's because we couldn't invalidate pagecache for 7513 * this range and we need to fallback to buffered. 7514 */ 7515 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, 7516 create)) { 7517 ret = -ENOTBLK; 7518 goto err; 7519 } 7520 7521 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 7522 if (IS_ERR(em)) { 7523 ret = PTR_ERR(em); 7524 goto unlock_err; 7525 } 7526 7527 /* 7528 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 7529 * io. INLINE is special, and we could probably kludge it in here, but 7530 * it's still buffered so for safety lets just fall back to the generic 7531 * buffered path. 7532 * 7533 * For COMPRESSED we _have_ to read the entire extent in so we can 7534 * decompress it, so there will be buffering required no matter what we 7535 * do, so go ahead and fallback to buffered. 7536 * 7537 * We return -ENOTBLK because thats what makes DIO go ahead and go back 7538 * to buffered IO. Don't blame me, this is the price we pay for using 7539 * the generic code. 7540 */ 7541 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 7542 em->block_start == EXTENT_MAP_INLINE) { 7543 free_extent_map(em); 7544 ret = -ENOTBLK; 7545 goto unlock_err; 7546 } 7547 7548 /* Just a good old fashioned hole, return */ 7549 if (!create && (em->block_start == EXTENT_MAP_HOLE || 7550 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 7551 free_extent_map(em); 7552 goto unlock_err; 7553 } 7554 7555 /* 7556 * We don't allocate a new extent in the following cases 7557 * 7558 * 1) The inode is marked as NODATACOW. In this case we'll just use the 7559 * existing extent. 7560 * 2) The extent is marked as PREALLOC. We're good to go here and can 7561 * just use the extent. 7562 * 7563 */ 7564 if (!create) { 7565 len = min(len, em->len - (start - em->start)); 7566 lockstart = start + len; 7567 goto unlock; 7568 } 7569 7570 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 7571 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 7572 em->block_start != EXTENT_MAP_HOLE)) { 7573 int type; 7574 u64 block_start, orig_start, orig_block_len, ram_bytes; 7575 7576 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7577 type = BTRFS_ORDERED_PREALLOC; 7578 else 7579 type = BTRFS_ORDERED_NOCOW; 7580 len = min(len, em->len - (start - em->start)); 7581 block_start = em->block_start + (start - em->start); 7582 7583 if (can_nocow_extent(inode, start, &len, &orig_start, 7584 &orig_block_len, &ram_bytes) == 1) { 7585 if (type == BTRFS_ORDERED_PREALLOC) { 7586 free_extent_map(em); 7587 em = create_pinned_em(inode, start, len, 7588 orig_start, 7589 block_start, len, 7590 orig_block_len, 7591 ram_bytes, type); 7592 if (IS_ERR(em)) { 7593 ret = PTR_ERR(em); 7594 goto unlock_err; 7595 } 7596 } 7597 7598 ret = btrfs_add_ordered_extent_dio(inode, start, 7599 block_start, len, len, type); 7600 if (ret) { 7601 free_extent_map(em); 7602 goto unlock_err; 7603 } 7604 goto unlock; 7605 } 7606 } 7607 7608 /* 7609 * this will cow the extent, reset the len in case we changed 7610 * it above 7611 */ 7612 len = bh_result->b_size; 7613 free_extent_map(em); 7614 em = btrfs_new_extent_direct(inode, start, len); 7615 if (IS_ERR(em)) { 7616 ret = PTR_ERR(em); 7617 goto unlock_err; 7618 } 7619 len = min(len, em->len - (start - em->start)); 7620 unlock: 7621 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 7622 inode->i_blkbits; 7623 bh_result->b_size = len; 7624 bh_result->b_bdev = em->bdev; 7625 set_buffer_mapped(bh_result); 7626 if (create) { 7627 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7628 set_buffer_new(bh_result); 7629 7630 /* 7631 * Need to update the i_size under the extent lock so buffered 7632 * readers will get the updated i_size when we unlock. 7633 */ 7634 if (start + len > i_size_read(inode)) 7635 i_size_write(inode, start + len); 7636 7637 adjust_dio_outstanding_extents(inode, dio_data, len); 7638 btrfs_free_reserved_data_space(inode, start, len); 7639 WARN_ON(dio_data->reserve < len); 7640 dio_data->reserve -= len; 7641 dio_data->unsubmitted_oe_range_end = start + len; 7642 current->journal_info = dio_data; 7643 } 7644 7645 /* 7646 * In the case of write we need to clear and unlock the entire range, 7647 * in the case of read we need to unlock only the end area that we 7648 * aren't using if there is any left over space. 7649 */ 7650 if (lockstart < lockend) { 7651 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 7652 lockend, unlock_bits, 1, 0, 7653 &cached_state, GFP_NOFS); 7654 } else { 7655 free_extent_state(cached_state); 7656 } 7657 7658 free_extent_map(em); 7659 7660 return 0; 7661 7662 unlock_err: 7663 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7664 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 7665 err: 7666 if (dio_data) 7667 current->journal_info = dio_data; 7668 /* 7669 * Compensate the delalloc release we do in btrfs_direct_IO() when we 7670 * write less data then expected, so that we don't underflow our inode's 7671 * outstanding extents counter. 7672 */ 7673 if (create && dio_data) 7674 adjust_dio_outstanding_extents(inode, dio_data, len); 7675 7676 return ret; 7677 } 7678 7679 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio, 7680 int rw, int mirror_num) 7681 { 7682 struct btrfs_root *root = BTRFS_I(inode)->root; 7683 int ret; 7684 7685 BUG_ON(rw & REQ_WRITE); 7686 7687 bio_get(bio); 7688 7689 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 7690 BTRFS_WQ_ENDIO_DIO_REPAIR); 7691 if (ret) 7692 goto err; 7693 7694 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 7695 err: 7696 bio_put(bio); 7697 return ret; 7698 } 7699 7700 static int btrfs_check_dio_repairable(struct inode *inode, 7701 struct bio *failed_bio, 7702 struct io_failure_record *failrec, 7703 int failed_mirror) 7704 { 7705 int num_copies; 7706 7707 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info, 7708 failrec->logical, failrec->len); 7709 if (num_copies == 1) { 7710 /* 7711 * we only have a single copy of the data, so don't bother with 7712 * all the retry and error correction code that follows. no 7713 * matter what the error is, it is very likely to persist. 7714 */ 7715 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", 7716 num_copies, failrec->this_mirror, failed_mirror); 7717 return 0; 7718 } 7719 7720 failrec->failed_mirror = failed_mirror; 7721 failrec->this_mirror++; 7722 if (failrec->this_mirror == failed_mirror) 7723 failrec->this_mirror++; 7724 7725 if (failrec->this_mirror > num_copies) { 7726 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", 7727 num_copies, failrec->this_mirror, failed_mirror); 7728 return 0; 7729 } 7730 7731 return 1; 7732 } 7733 7734 static int dio_read_error(struct inode *inode, struct bio *failed_bio, 7735 struct page *page, u64 start, u64 end, 7736 int failed_mirror, bio_end_io_t *repair_endio, 7737 void *repair_arg) 7738 { 7739 struct io_failure_record *failrec; 7740 struct bio *bio; 7741 int isector; 7742 int read_mode; 7743 int ret; 7744 7745 BUG_ON(failed_bio->bi_rw & REQ_WRITE); 7746 7747 ret = btrfs_get_io_failure_record(inode, start, end, &failrec); 7748 if (ret) 7749 return ret; 7750 7751 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec, 7752 failed_mirror); 7753 if (!ret) { 7754 free_io_failure(inode, failrec); 7755 return -EIO; 7756 } 7757 7758 if (failed_bio->bi_vcnt > 1) 7759 read_mode = READ_SYNC | REQ_FAILFAST_DEV; 7760 else 7761 read_mode = READ_SYNC; 7762 7763 isector = start - btrfs_io_bio(failed_bio)->logical; 7764 isector >>= inode->i_sb->s_blocksize_bits; 7765 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, 7766 0, isector, repair_endio, repair_arg); 7767 if (!bio) { 7768 free_io_failure(inode, failrec); 7769 return -EIO; 7770 } 7771 7772 btrfs_debug(BTRFS_I(inode)->root->fs_info, 7773 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n", 7774 read_mode, failrec->this_mirror, failrec->in_validation); 7775 7776 ret = submit_dio_repair_bio(inode, bio, read_mode, 7777 failrec->this_mirror); 7778 if (ret) { 7779 free_io_failure(inode, failrec); 7780 bio_put(bio); 7781 } 7782 7783 return ret; 7784 } 7785 7786 struct btrfs_retry_complete { 7787 struct completion done; 7788 struct inode *inode; 7789 u64 start; 7790 int uptodate; 7791 }; 7792 7793 static void btrfs_retry_endio_nocsum(struct bio *bio) 7794 { 7795 struct btrfs_retry_complete *done = bio->bi_private; 7796 struct bio_vec *bvec; 7797 int i; 7798 7799 if (bio->bi_error) 7800 goto end; 7801 7802 done->uptodate = 1; 7803 bio_for_each_segment_all(bvec, bio, i) 7804 clean_io_failure(done->inode, done->start, bvec->bv_page, 0); 7805 end: 7806 complete(&done->done); 7807 bio_put(bio); 7808 } 7809 7810 static int __btrfs_correct_data_nocsum(struct inode *inode, 7811 struct btrfs_io_bio *io_bio) 7812 { 7813 struct bio_vec *bvec; 7814 struct btrfs_retry_complete done; 7815 u64 start; 7816 int i; 7817 int ret; 7818 7819 start = io_bio->logical; 7820 done.inode = inode; 7821 7822 bio_for_each_segment_all(bvec, &io_bio->bio, i) { 7823 try_again: 7824 done.uptodate = 0; 7825 done.start = start; 7826 init_completion(&done.done); 7827 7828 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start, 7829 start + bvec->bv_len - 1, 7830 io_bio->mirror_num, 7831 btrfs_retry_endio_nocsum, &done); 7832 if (ret) 7833 return ret; 7834 7835 wait_for_completion(&done.done); 7836 7837 if (!done.uptodate) { 7838 /* We might have another mirror, so try again */ 7839 goto try_again; 7840 } 7841 7842 start += bvec->bv_len; 7843 } 7844 7845 return 0; 7846 } 7847 7848 static void btrfs_retry_endio(struct bio *bio) 7849 { 7850 struct btrfs_retry_complete *done = bio->bi_private; 7851 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 7852 struct bio_vec *bvec; 7853 int uptodate; 7854 int ret; 7855 int i; 7856 7857 if (bio->bi_error) 7858 goto end; 7859 7860 uptodate = 1; 7861 bio_for_each_segment_all(bvec, bio, i) { 7862 ret = __readpage_endio_check(done->inode, io_bio, i, 7863 bvec->bv_page, 0, 7864 done->start, bvec->bv_len); 7865 if (!ret) 7866 clean_io_failure(done->inode, done->start, 7867 bvec->bv_page, 0); 7868 else 7869 uptodate = 0; 7870 } 7871 7872 done->uptodate = uptodate; 7873 end: 7874 complete(&done->done); 7875 bio_put(bio); 7876 } 7877 7878 static int __btrfs_subio_endio_read(struct inode *inode, 7879 struct btrfs_io_bio *io_bio, int err) 7880 { 7881 struct bio_vec *bvec; 7882 struct btrfs_retry_complete done; 7883 u64 start; 7884 u64 offset = 0; 7885 int i; 7886 int ret; 7887 7888 err = 0; 7889 start = io_bio->logical; 7890 done.inode = inode; 7891 7892 bio_for_each_segment_all(bvec, &io_bio->bio, i) { 7893 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page, 7894 0, start, bvec->bv_len); 7895 if (likely(!ret)) 7896 goto next; 7897 try_again: 7898 done.uptodate = 0; 7899 done.start = start; 7900 init_completion(&done.done); 7901 7902 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start, 7903 start + bvec->bv_len - 1, 7904 io_bio->mirror_num, 7905 btrfs_retry_endio, &done); 7906 if (ret) { 7907 err = ret; 7908 goto next; 7909 } 7910 7911 wait_for_completion(&done.done); 7912 7913 if (!done.uptodate) { 7914 /* We might have another mirror, so try again */ 7915 goto try_again; 7916 } 7917 next: 7918 offset += bvec->bv_len; 7919 start += bvec->bv_len; 7920 } 7921 7922 return err; 7923 } 7924 7925 static int btrfs_subio_endio_read(struct inode *inode, 7926 struct btrfs_io_bio *io_bio, int err) 7927 { 7928 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 7929 7930 if (skip_csum) { 7931 if (unlikely(err)) 7932 return __btrfs_correct_data_nocsum(inode, io_bio); 7933 else 7934 return 0; 7935 } else { 7936 return __btrfs_subio_endio_read(inode, io_bio, err); 7937 } 7938 } 7939 7940 static void btrfs_endio_direct_read(struct bio *bio) 7941 { 7942 struct btrfs_dio_private *dip = bio->bi_private; 7943 struct inode *inode = dip->inode; 7944 struct bio *dio_bio; 7945 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 7946 int err = bio->bi_error; 7947 7948 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) 7949 err = btrfs_subio_endio_read(inode, io_bio, err); 7950 7951 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 7952 dip->logical_offset + dip->bytes - 1); 7953 dio_bio = dip->dio_bio; 7954 7955 kfree(dip); 7956 7957 dio_end_io(dio_bio, bio->bi_error); 7958 7959 if (io_bio->end_io) 7960 io_bio->end_io(io_bio, err); 7961 bio_put(bio); 7962 } 7963 7964 static void btrfs_endio_direct_write_update_ordered(struct inode *inode, 7965 const u64 offset, 7966 const u64 bytes, 7967 const int uptodate) 7968 { 7969 struct btrfs_root *root = BTRFS_I(inode)->root; 7970 struct btrfs_ordered_extent *ordered = NULL; 7971 u64 ordered_offset = offset; 7972 u64 ordered_bytes = bytes; 7973 int ret; 7974 7975 again: 7976 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 7977 &ordered_offset, 7978 ordered_bytes, 7979 uptodate); 7980 if (!ret) 7981 goto out_test; 7982 7983 btrfs_init_work(&ordered->work, btrfs_endio_write_helper, 7984 finish_ordered_fn, NULL, NULL); 7985 btrfs_queue_work(root->fs_info->endio_write_workers, 7986 &ordered->work); 7987 out_test: 7988 /* 7989 * our bio might span multiple ordered extents. If we haven't 7990 * completed the accounting for the whole dio, go back and try again 7991 */ 7992 if (ordered_offset < offset + bytes) { 7993 ordered_bytes = offset + bytes - ordered_offset; 7994 ordered = NULL; 7995 goto again; 7996 } 7997 } 7998 7999 static void btrfs_endio_direct_write(struct bio *bio) 8000 { 8001 struct btrfs_dio_private *dip = bio->bi_private; 8002 struct bio *dio_bio = dip->dio_bio; 8003 8004 btrfs_endio_direct_write_update_ordered(dip->inode, 8005 dip->logical_offset, 8006 dip->bytes, 8007 !bio->bi_error); 8008 8009 kfree(dip); 8010 8011 dio_end_io(dio_bio, bio->bi_error); 8012 bio_put(bio); 8013 } 8014 8015 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, 8016 struct bio *bio, int mirror_num, 8017 unsigned long bio_flags, u64 offset) 8018 { 8019 int ret; 8020 struct btrfs_root *root = BTRFS_I(inode)->root; 8021 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); 8022 BUG_ON(ret); /* -ENOMEM */ 8023 return 0; 8024 } 8025 8026 static void btrfs_end_dio_bio(struct bio *bio) 8027 { 8028 struct btrfs_dio_private *dip = bio->bi_private; 8029 int err = bio->bi_error; 8030 8031 if (err) 8032 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info, 8033 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d", 8034 btrfs_ino(dip->inode), bio->bi_rw, 8035 (unsigned long long)bio->bi_iter.bi_sector, 8036 bio->bi_iter.bi_size, err); 8037 8038 if (dip->subio_endio) 8039 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err); 8040 8041 if (err) { 8042 dip->errors = 1; 8043 8044 /* 8045 * before atomic variable goto zero, we must make sure 8046 * dip->errors is perceived to be set. 8047 */ 8048 smp_mb__before_atomic(); 8049 } 8050 8051 /* if there are more bios still pending for this dio, just exit */ 8052 if (!atomic_dec_and_test(&dip->pending_bios)) 8053 goto out; 8054 8055 if (dip->errors) { 8056 bio_io_error(dip->orig_bio); 8057 } else { 8058 dip->dio_bio->bi_error = 0; 8059 bio_endio(dip->orig_bio); 8060 } 8061 out: 8062 bio_put(bio); 8063 } 8064 8065 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 8066 u64 first_sector, gfp_t gfp_flags) 8067 { 8068 struct bio *bio; 8069 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags); 8070 if (bio) 8071 bio_associate_current(bio); 8072 return bio; 8073 } 8074 8075 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root, 8076 struct inode *inode, 8077 struct btrfs_dio_private *dip, 8078 struct bio *bio, 8079 u64 file_offset) 8080 { 8081 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 8082 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio); 8083 int ret; 8084 8085 /* 8086 * We load all the csum data we need when we submit 8087 * the first bio to reduce the csum tree search and 8088 * contention. 8089 */ 8090 if (dip->logical_offset == file_offset) { 8091 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, 8092 file_offset); 8093 if (ret) 8094 return ret; 8095 } 8096 8097 if (bio == dip->orig_bio) 8098 return 0; 8099 8100 file_offset -= dip->logical_offset; 8101 file_offset >>= inode->i_sb->s_blocksize_bits; 8102 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset); 8103 8104 return 0; 8105 } 8106 8107 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 8108 int rw, u64 file_offset, int skip_sum, 8109 int async_submit) 8110 { 8111 struct btrfs_dio_private *dip = bio->bi_private; 8112 int write = rw & REQ_WRITE; 8113 struct btrfs_root *root = BTRFS_I(inode)->root; 8114 int ret; 8115 8116 if (async_submit) 8117 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 8118 8119 bio_get(bio); 8120 8121 if (!write) { 8122 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 8123 BTRFS_WQ_ENDIO_DATA); 8124 if (ret) 8125 goto err; 8126 } 8127 8128 if (skip_sum) 8129 goto map; 8130 8131 if (write && async_submit) { 8132 ret = btrfs_wq_submit_bio(root->fs_info, 8133 inode, rw, bio, 0, 0, 8134 file_offset, 8135 __btrfs_submit_bio_start_direct_io, 8136 __btrfs_submit_bio_done); 8137 goto err; 8138 } else if (write) { 8139 /* 8140 * If we aren't doing async submit, calculate the csum of the 8141 * bio now. 8142 */ 8143 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); 8144 if (ret) 8145 goto err; 8146 } else { 8147 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio, 8148 file_offset); 8149 if (ret) 8150 goto err; 8151 } 8152 map: 8153 ret = btrfs_map_bio(root, rw, bio, 0, async_submit); 8154 err: 8155 bio_put(bio); 8156 return ret; 8157 } 8158 8159 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, 8160 int skip_sum) 8161 { 8162 struct inode *inode = dip->inode; 8163 struct btrfs_root *root = BTRFS_I(inode)->root; 8164 struct bio *bio; 8165 struct bio *orig_bio = dip->orig_bio; 8166 struct bio_vec *bvec = orig_bio->bi_io_vec; 8167 u64 start_sector = orig_bio->bi_iter.bi_sector; 8168 u64 file_offset = dip->logical_offset; 8169 u64 submit_len = 0; 8170 u64 map_length; 8171 int nr_pages = 0; 8172 int ret; 8173 int async_submit = 0; 8174 8175 map_length = orig_bio->bi_iter.bi_size; 8176 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, 8177 &map_length, NULL, 0); 8178 if (ret) 8179 return -EIO; 8180 8181 if (map_length >= orig_bio->bi_iter.bi_size) { 8182 bio = orig_bio; 8183 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED; 8184 goto submit; 8185 } 8186 8187 /* async crcs make it difficult to collect full stripe writes. */ 8188 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK) 8189 async_submit = 0; 8190 else 8191 async_submit = 1; 8192 8193 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 8194 if (!bio) 8195 return -ENOMEM; 8196 8197 bio->bi_private = dip; 8198 bio->bi_end_io = btrfs_end_dio_bio; 8199 btrfs_io_bio(bio)->logical = file_offset; 8200 atomic_inc(&dip->pending_bios); 8201 8202 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { 8203 if (map_length < submit_len + bvec->bv_len || 8204 bio_add_page(bio, bvec->bv_page, bvec->bv_len, 8205 bvec->bv_offset) < bvec->bv_len) { 8206 /* 8207 * inc the count before we submit the bio so 8208 * we know the end IO handler won't happen before 8209 * we inc the count. Otherwise, the dip might get freed 8210 * before we're done setting it up 8211 */ 8212 atomic_inc(&dip->pending_bios); 8213 ret = __btrfs_submit_dio_bio(bio, inode, rw, 8214 file_offset, skip_sum, 8215 async_submit); 8216 if (ret) { 8217 bio_put(bio); 8218 atomic_dec(&dip->pending_bios); 8219 goto out_err; 8220 } 8221 8222 start_sector += submit_len >> 9; 8223 file_offset += submit_len; 8224 8225 submit_len = 0; 8226 nr_pages = 0; 8227 8228 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 8229 start_sector, GFP_NOFS); 8230 if (!bio) 8231 goto out_err; 8232 bio->bi_private = dip; 8233 bio->bi_end_io = btrfs_end_dio_bio; 8234 btrfs_io_bio(bio)->logical = file_offset; 8235 8236 map_length = orig_bio->bi_iter.bi_size; 8237 ret = btrfs_map_block(root->fs_info, rw, 8238 start_sector << 9, 8239 &map_length, NULL, 0); 8240 if (ret) { 8241 bio_put(bio); 8242 goto out_err; 8243 } 8244 } else { 8245 submit_len += bvec->bv_len; 8246 nr_pages++; 8247 bvec++; 8248 } 8249 } 8250 8251 submit: 8252 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, 8253 async_submit); 8254 if (!ret) 8255 return 0; 8256 8257 bio_put(bio); 8258 out_err: 8259 dip->errors = 1; 8260 /* 8261 * before atomic variable goto zero, we must 8262 * make sure dip->errors is perceived to be set. 8263 */ 8264 smp_mb__before_atomic(); 8265 if (atomic_dec_and_test(&dip->pending_bios)) 8266 bio_io_error(dip->orig_bio); 8267 8268 /* bio_end_io() will handle error, so we needn't return it */ 8269 return 0; 8270 } 8271 8272 static void btrfs_submit_direct(int rw, struct bio *dio_bio, 8273 struct inode *inode, loff_t file_offset) 8274 { 8275 struct btrfs_dio_private *dip = NULL; 8276 struct bio *io_bio = NULL; 8277 struct btrfs_io_bio *btrfs_bio; 8278 int skip_sum; 8279 int write = rw & REQ_WRITE; 8280 int ret = 0; 8281 8282 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 8283 8284 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); 8285 if (!io_bio) { 8286 ret = -ENOMEM; 8287 goto free_ordered; 8288 } 8289 8290 dip = kzalloc(sizeof(*dip), GFP_NOFS); 8291 if (!dip) { 8292 ret = -ENOMEM; 8293 goto free_ordered; 8294 } 8295 8296 dip->private = dio_bio->bi_private; 8297 dip->inode = inode; 8298 dip->logical_offset = file_offset; 8299 dip->bytes = dio_bio->bi_iter.bi_size; 8300 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; 8301 io_bio->bi_private = dip; 8302 dip->orig_bio = io_bio; 8303 dip->dio_bio = dio_bio; 8304 atomic_set(&dip->pending_bios, 0); 8305 btrfs_bio = btrfs_io_bio(io_bio); 8306 btrfs_bio->logical = file_offset; 8307 8308 if (write) { 8309 io_bio->bi_end_io = btrfs_endio_direct_write; 8310 } else { 8311 io_bio->bi_end_io = btrfs_endio_direct_read; 8312 dip->subio_endio = btrfs_subio_endio_read; 8313 } 8314 8315 /* 8316 * Reset the range for unsubmitted ordered extents (to a 0 length range) 8317 * even if we fail to submit a bio, because in such case we do the 8318 * corresponding error handling below and it must not be done a second 8319 * time by btrfs_direct_IO(). 8320 */ 8321 if (write) { 8322 struct btrfs_dio_data *dio_data = current->journal_info; 8323 8324 dio_data->unsubmitted_oe_range_end = dip->logical_offset + 8325 dip->bytes; 8326 dio_data->unsubmitted_oe_range_start = 8327 dio_data->unsubmitted_oe_range_end; 8328 } 8329 8330 ret = btrfs_submit_direct_hook(rw, dip, skip_sum); 8331 if (!ret) 8332 return; 8333 8334 if (btrfs_bio->end_io) 8335 btrfs_bio->end_io(btrfs_bio, ret); 8336 8337 free_ordered: 8338 /* 8339 * If we arrived here it means either we failed to submit the dip 8340 * or we either failed to clone the dio_bio or failed to allocate the 8341 * dip. If we cloned the dio_bio and allocated the dip, we can just 8342 * call bio_endio against our io_bio so that we get proper resource 8343 * cleanup if we fail to submit the dip, otherwise, we must do the 8344 * same as btrfs_endio_direct_[write|read] because we can't call these 8345 * callbacks - they require an allocated dip and a clone of dio_bio. 8346 */ 8347 if (io_bio && dip) { 8348 io_bio->bi_error = -EIO; 8349 bio_endio(io_bio); 8350 /* 8351 * The end io callbacks free our dip, do the final put on io_bio 8352 * and all the cleanup and final put for dio_bio (through 8353 * dio_end_io()). 8354 */ 8355 dip = NULL; 8356 io_bio = NULL; 8357 } else { 8358 if (write) 8359 btrfs_endio_direct_write_update_ordered(inode, 8360 file_offset, 8361 dio_bio->bi_iter.bi_size, 8362 0); 8363 else 8364 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset, 8365 file_offset + dio_bio->bi_iter.bi_size - 1); 8366 8367 dio_bio->bi_error = -EIO; 8368 /* 8369 * Releases and cleans up our dio_bio, no need to bio_put() 8370 * nor bio_endio()/bio_io_error() against dio_bio. 8371 */ 8372 dio_end_io(dio_bio, ret); 8373 } 8374 if (io_bio) 8375 bio_put(io_bio); 8376 kfree(dip); 8377 } 8378 8379 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb, 8380 const struct iov_iter *iter, loff_t offset) 8381 { 8382 int seg; 8383 int i; 8384 unsigned blocksize_mask = root->sectorsize - 1; 8385 ssize_t retval = -EINVAL; 8386 8387 if (offset & blocksize_mask) 8388 goto out; 8389 8390 if (iov_iter_alignment(iter) & blocksize_mask) 8391 goto out; 8392 8393 /* If this is a write we don't need to check anymore */ 8394 if (iov_iter_rw(iter) == WRITE) 8395 return 0; 8396 /* 8397 * Check to make sure we don't have duplicate iov_base's in this 8398 * iovec, if so return EINVAL, otherwise we'll get csum errors 8399 * when reading back. 8400 */ 8401 for (seg = 0; seg < iter->nr_segs; seg++) { 8402 for (i = seg + 1; i < iter->nr_segs; i++) { 8403 if (iter->iov[seg].iov_base == iter->iov[i].iov_base) 8404 goto out; 8405 } 8406 } 8407 retval = 0; 8408 out: 8409 return retval; 8410 } 8411 8412 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, 8413 loff_t offset) 8414 { 8415 struct file *file = iocb->ki_filp; 8416 struct inode *inode = file->f_mapping->host; 8417 struct btrfs_root *root = BTRFS_I(inode)->root; 8418 struct btrfs_dio_data dio_data = { 0 }; 8419 size_t count = 0; 8420 int flags = 0; 8421 bool wakeup = true; 8422 bool relock = false; 8423 ssize_t ret; 8424 8425 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset)) 8426 return 0; 8427 8428 inode_dio_begin(inode); 8429 smp_mb__after_atomic(); 8430 8431 /* 8432 * The generic stuff only does filemap_write_and_wait_range, which 8433 * isn't enough if we've written compressed pages to this area, so 8434 * we need to flush the dirty pages again to make absolutely sure 8435 * that any outstanding dirty pages are on disk. 8436 */ 8437 count = iov_iter_count(iter); 8438 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 8439 &BTRFS_I(inode)->runtime_flags)) 8440 filemap_fdatawrite_range(inode->i_mapping, offset, 8441 offset + count - 1); 8442 8443 if (iov_iter_rw(iter) == WRITE) { 8444 /* 8445 * If the write DIO is beyond the EOF, we need update 8446 * the isize, but it is protected by i_mutex. So we can 8447 * not unlock the i_mutex at this case. 8448 */ 8449 if (offset + count <= inode->i_size) { 8450 inode_unlock(inode); 8451 relock = true; 8452 } 8453 ret = btrfs_delalloc_reserve_space(inode, offset, count); 8454 if (ret) 8455 goto out; 8456 dio_data.outstanding_extents = div64_u64(count + 8457 BTRFS_MAX_EXTENT_SIZE - 1, 8458 BTRFS_MAX_EXTENT_SIZE); 8459 8460 /* 8461 * We need to know how many extents we reserved so that we can 8462 * do the accounting properly if we go over the number we 8463 * originally calculated. Abuse current->journal_info for this. 8464 */ 8465 dio_data.reserve = round_up(count, root->sectorsize); 8466 dio_data.unsubmitted_oe_range_start = (u64)offset; 8467 dio_data.unsubmitted_oe_range_end = (u64)offset; 8468 current->journal_info = &dio_data; 8469 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 8470 &BTRFS_I(inode)->runtime_flags)) { 8471 inode_dio_end(inode); 8472 flags = DIO_LOCKING | DIO_SKIP_HOLES; 8473 wakeup = false; 8474 } 8475 8476 ret = __blockdev_direct_IO(iocb, inode, 8477 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, 8478 iter, offset, btrfs_get_blocks_direct, NULL, 8479 btrfs_submit_direct, flags); 8480 if (iov_iter_rw(iter) == WRITE) { 8481 current->journal_info = NULL; 8482 if (ret < 0 && ret != -EIOCBQUEUED) { 8483 if (dio_data.reserve) 8484 btrfs_delalloc_release_space(inode, offset, 8485 dio_data.reserve); 8486 /* 8487 * On error we might have left some ordered extents 8488 * without submitting corresponding bios for them, so 8489 * cleanup them up to avoid other tasks getting them 8490 * and waiting for them to complete forever. 8491 */ 8492 if (dio_data.unsubmitted_oe_range_start < 8493 dio_data.unsubmitted_oe_range_end) 8494 btrfs_endio_direct_write_update_ordered(inode, 8495 dio_data.unsubmitted_oe_range_start, 8496 dio_data.unsubmitted_oe_range_end - 8497 dio_data.unsubmitted_oe_range_start, 8498 0); 8499 } else if (ret >= 0 && (size_t)ret < count) 8500 btrfs_delalloc_release_space(inode, offset, 8501 count - (size_t)ret); 8502 } 8503 out: 8504 if (wakeup) 8505 inode_dio_end(inode); 8506 if (relock) 8507 inode_lock(inode); 8508 8509 return ret; 8510 } 8511 8512 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 8513 8514 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 8515 __u64 start, __u64 len) 8516 { 8517 int ret; 8518 8519 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 8520 if (ret) 8521 return ret; 8522 8523 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 8524 } 8525 8526 int btrfs_readpage(struct file *file, struct page *page) 8527 { 8528 struct extent_io_tree *tree; 8529 tree = &BTRFS_I(page->mapping->host)->io_tree; 8530 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 8531 } 8532 8533 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 8534 { 8535 struct extent_io_tree *tree; 8536 struct inode *inode = page->mapping->host; 8537 int ret; 8538 8539 if (current->flags & PF_MEMALLOC) { 8540 redirty_page_for_writepage(wbc, page); 8541 unlock_page(page); 8542 return 0; 8543 } 8544 8545 /* 8546 * If we are under memory pressure we will call this directly from the 8547 * VM, we need to make sure we have the inode referenced for the ordered 8548 * extent. If not just return like we didn't do anything. 8549 */ 8550 if (!igrab(inode)) { 8551 redirty_page_for_writepage(wbc, page); 8552 return AOP_WRITEPAGE_ACTIVATE; 8553 } 8554 tree = &BTRFS_I(page->mapping->host)->io_tree; 8555 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc); 8556 btrfs_add_delayed_iput(inode); 8557 return ret; 8558 } 8559 8560 static int btrfs_writepages(struct address_space *mapping, 8561 struct writeback_control *wbc) 8562 { 8563 struct extent_io_tree *tree; 8564 8565 tree = &BTRFS_I(mapping->host)->io_tree; 8566 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 8567 } 8568 8569 static int 8570 btrfs_readpages(struct file *file, struct address_space *mapping, 8571 struct list_head *pages, unsigned nr_pages) 8572 { 8573 struct extent_io_tree *tree; 8574 tree = &BTRFS_I(mapping->host)->io_tree; 8575 return extent_readpages(tree, mapping, pages, nr_pages, 8576 btrfs_get_extent); 8577 } 8578 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 8579 { 8580 struct extent_io_tree *tree; 8581 struct extent_map_tree *map; 8582 int ret; 8583 8584 tree = &BTRFS_I(page->mapping->host)->io_tree; 8585 map = &BTRFS_I(page->mapping->host)->extent_tree; 8586 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 8587 if (ret == 1) { 8588 ClearPagePrivate(page); 8589 set_page_private(page, 0); 8590 page_cache_release(page); 8591 } 8592 return ret; 8593 } 8594 8595 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 8596 { 8597 if (PageWriteback(page) || PageDirty(page)) 8598 return 0; 8599 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); 8600 } 8601 8602 static void btrfs_invalidatepage(struct page *page, unsigned int offset, 8603 unsigned int length) 8604 { 8605 struct inode *inode = page->mapping->host; 8606 struct extent_io_tree *tree; 8607 struct btrfs_ordered_extent *ordered; 8608 struct extent_state *cached_state = NULL; 8609 u64 page_start = page_offset(page); 8610 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 8611 int inode_evicting = inode->i_state & I_FREEING; 8612 8613 /* 8614 * we have the page locked, so new writeback can't start, 8615 * and the dirty bit won't be cleared while we are here. 8616 * 8617 * Wait for IO on this page so that we can safely clear 8618 * the PagePrivate2 bit and do ordered accounting 8619 */ 8620 wait_on_page_writeback(page); 8621 8622 tree = &BTRFS_I(inode)->io_tree; 8623 if (offset) { 8624 btrfs_releasepage(page, GFP_NOFS); 8625 return; 8626 } 8627 8628 if (!inode_evicting) 8629 lock_extent_bits(tree, page_start, page_end, &cached_state); 8630 ordered = btrfs_lookup_ordered_extent(inode, page_start); 8631 if (ordered) { 8632 /* 8633 * IO on this page will never be started, so we need 8634 * to account for any ordered extents now 8635 */ 8636 if (!inode_evicting) 8637 clear_extent_bit(tree, page_start, page_end, 8638 EXTENT_DIRTY | EXTENT_DELALLOC | 8639 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 8640 EXTENT_DEFRAG, 1, 0, &cached_state, 8641 GFP_NOFS); 8642 /* 8643 * whoever cleared the private bit is responsible 8644 * for the finish_ordered_io 8645 */ 8646 if (TestClearPagePrivate2(page)) { 8647 struct btrfs_ordered_inode_tree *tree; 8648 u64 new_len; 8649 8650 tree = &BTRFS_I(inode)->ordered_tree; 8651 8652 spin_lock_irq(&tree->lock); 8653 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); 8654 new_len = page_start - ordered->file_offset; 8655 if (new_len < ordered->truncated_len) 8656 ordered->truncated_len = new_len; 8657 spin_unlock_irq(&tree->lock); 8658 8659 if (btrfs_dec_test_ordered_pending(inode, &ordered, 8660 page_start, 8661 PAGE_CACHE_SIZE, 1)) 8662 btrfs_finish_ordered_io(ordered); 8663 } 8664 btrfs_put_ordered_extent(ordered); 8665 if (!inode_evicting) { 8666 cached_state = NULL; 8667 lock_extent_bits(tree, page_start, page_end, 8668 &cached_state); 8669 } 8670 } 8671 8672 /* 8673 * Qgroup reserved space handler 8674 * Page here will be either 8675 * 1) Already written to disk 8676 * In this case, its reserved space is released from data rsv map 8677 * and will be freed by delayed_ref handler finally. 8678 * So even we call qgroup_free_data(), it won't decrease reserved 8679 * space. 8680 * 2) Not written to disk 8681 * This means the reserved space should be freed here. 8682 */ 8683 btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE); 8684 if (!inode_evicting) { 8685 clear_extent_bit(tree, page_start, page_end, 8686 EXTENT_LOCKED | EXTENT_DIRTY | 8687 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 8688 EXTENT_DEFRAG, 1, 1, 8689 &cached_state, GFP_NOFS); 8690 8691 __btrfs_releasepage(page, GFP_NOFS); 8692 } 8693 8694 ClearPageChecked(page); 8695 if (PagePrivate(page)) { 8696 ClearPagePrivate(page); 8697 set_page_private(page, 0); 8698 page_cache_release(page); 8699 } 8700 } 8701 8702 /* 8703 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 8704 * called from a page fault handler when a page is first dirtied. Hence we must 8705 * be careful to check for EOF conditions here. We set the page up correctly 8706 * for a written page which means we get ENOSPC checking when writing into 8707 * holes and correct delalloc and unwritten extent mapping on filesystems that 8708 * support these features. 8709 * 8710 * We are not allowed to take the i_mutex here so we have to play games to 8711 * protect against truncate races as the page could now be beyond EOF. Because 8712 * vmtruncate() writes the inode size before removing pages, once we have the 8713 * page lock we can determine safely if the page is beyond EOF. If it is not 8714 * beyond EOF, then the page is guaranteed safe against truncation until we 8715 * unlock the page. 8716 */ 8717 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 8718 { 8719 struct page *page = vmf->page; 8720 struct inode *inode = file_inode(vma->vm_file); 8721 struct btrfs_root *root = BTRFS_I(inode)->root; 8722 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 8723 struct btrfs_ordered_extent *ordered; 8724 struct extent_state *cached_state = NULL; 8725 char *kaddr; 8726 unsigned long zero_start; 8727 loff_t size; 8728 int ret; 8729 int reserved = 0; 8730 u64 page_start; 8731 u64 page_end; 8732 8733 sb_start_pagefault(inode->i_sb); 8734 page_start = page_offset(page); 8735 page_end = page_start + PAGE_CACHE_SIZE - 1; 8736 8737 ret = btrfs_delalloc_reserve_space(inode, page_start, 8738 PAGE_CACHE_SIZE); 8739 if (!ret) { 8740 ret = file_update_time(vma->vm_file); 8741 reserved = 1; 8742 } 8743 if (ret) { 8744 if (ret == -ENOMEM) 8745 ret = VM_FAULT_OOM; 8746 else /* -ENOSPC, -EIO, etc */ 8747 ret = VM_FAULT_SIGBUS; 8748 if (reserved) 8749 goto out; 8750 goto out_noreserve; 8751 } 8752 8753 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 8754 again: 8755 lock_page(page); 8756 size = i_size_read(inode); 8757 8758 if ((page->mapping != inode->i_mapping) || 8759 (page_start >= size)) { 8760 /* page got truncated out from underneath us */ 8761 goto out_unlock; 8762 } 8763 wait_on_page_writeback(page); 8764 8765 lock_extent_bits(io_tree, page_start, page_end, &cached_state); 8766 set_page_extent_mapped(page); 8767 8768 /* 8769 * we can't set the delalloc bits if there are pending ordered 8770 * extents. Drop our locks and wait for them to finish 8771 */ 8772 ordered = btrfs_lookup_ordered_extent(inode, page_start); 8773 if (ordered) { 8774 unlock_extent_cached(io_tree, page_start, page_end, 8775 &cached_state, GFP_NOFS); 8776 unlock_page(page); 8777 btrfs_start_ordered_extent(inode, ordered, 1); 8778 btrfs_put_ordered_extent(ordered); 8779 goto again; 8780 } 8781 8782 /* 8783 * XXX - page_mkwrite gets called every time the page is dirtied, even 8784 * if it was already dirty, so for space accounting reasons we need to 8785 * clear any delalloc bits for the range we are fixing to save. There 8786 * is probably a better way to do this, but for now keep consistent with 8787 * prepare_pages in the normal write path. 8788 */ 8789 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 8790 EXTENT_DIRTY | EXTENT_DELALLOC | 8791 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 8792 0, 0, &cached_state, GFP_NOFS); 8793 8794 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 8795 &cached_state); 8796 if (ret) { 8797 unlock_extent_cached(io_tree, page_start, page_end, 8798 &cached_state, GFP_NOFS); 8799 ret = VM_FAULT_SIGBUS; 8800 goto out_unlock; 8801 } 8802 ret = 0; 8803 8804 /* page is wholly or partially inside EOF */ 8805 if (page_start + PAGE_CACHE_SIZE > size) 8806 zero_start = size & ~PAGE_CACHE_MASK; 8807 else 8808 zero_start = PAGE_CACHE_SIZE; 8809 8810 if (zero_start != PAGE_CACHE_SIZE) { 8811 kaddr = kmap(page); 8812 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); 8813 flush_dcache_page(page); 8814 kunmap(page); 8815 } 8816 ClearPageChecked(page); 8817 set_page_dirty(page); 8818 SetPageUptodate(page); 8819 8820 BTRFS_I(inode)->last_trans = root->fs_info->generation; 8821 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 8822 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 8823 8824 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 8825 8826 out_unlock: 8827 if (!ret) { 8828 sb_end_pagefault(inode->i_sb); 8829 return VM_FAULT_LOCKED; 8830 } 8831 unlock_page(page); 8832 out: 8833 btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE); 8834 out_noreserve: 8835 sb_end_pagefault(inode->i_sb); 8836 return ret; 8837 } 8838 8839 static int btrfs_truncate(struct inode *inode) 8840 { 8841 struct btrfs_root *root = BTRFS_I(inode)->root; 8842 struct btrfs_block_rsv *rsv; 8843 int ret = 0; 8844 int err = 0; 8845 struct btrfs_trans_handle *trans; 8846 u64 mask = root->sectorsize - 1; 8847 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 8848 8849 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), 8850 (u64)-1); 8851 if (ret) 8852 return ret; 8853 8854 /* 8855 * Yes ladies and gentelment, this is indeed ugly. The fact is we have 8856 * 3 things going on here 8857 * 8858 * 1) We need to reserve space for our orphan item and the space to 8859 * delete our orphan item. Lord knows we don't want to have a dangling 8860 * orphan item because we didn't reserve space to remove it. 8861 * 8862 * 2) We need to reserve space to update our inode. 8863 * 8864 * 3) We need to have something to cache all the space that is going to 8865 * be free'd up by the truncate operation, but also have some slack 8866 * space reserved in case it uses space during the truncate (thank you 8867 * very much snapshotting). 8868 * 8869 * And we need these to all be seperate. The fact is we can use alot of 8870 * space doing the truncate, and we have no earthly idea how much space 8871 * we will use, so we need the truncate reservation to be seperate so it 8872 * doesn't end up using space reserved for updating the inode or 8873 * removing the orphan item. We also need to be able to stop the 8874 * transaction and start a new one, which means we need to be able to 8875 * update the inode several times, and we have no idea of knowing how 8876 * many times that will be, so we can't just reserve 1 item for the 8877 * entirety of the opration, so that has to be done seperately as well. 8878 * Then there is the orphan item, which does indeed need to be held on 8879 * to for the whole operation, and we need nobody to touch this reserved 8880 * space except the orphan code. 8881 * 8882 * So that leaves us with 8883 * 8884 * 1) root->orphan_block_rsv - for the orphan deletion. 8885 * 2) rsv - for the truncate reservation, which we will steal from the 8886 * transaction reservation. 8887 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 8888 * updating the inode. 8889 */ 8890 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 8891 if (!rsv) 8892 return -ENOMEM; 8893 rsv->size = min_size; 8894 rsv->failfast = 1; 8895 8896 /* 8897 * 1 for the truncate slack space 8898 * 1 for updating the inode. 8899 */ 8900 trans = btrfs_start_transaction(root, 2); 8901 if (IS_ERR(trans)) { 8902 err = PTR_ERR(trans); 8903 goto out; 8904 } 8905 8906 /* Migrate the slack space for the truncate to our reserve */ 8907 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, 8908 min_size); 8909 BUG_ON(ret); 8910 8911 /* 8912 * So if we truncate and then write and fsync we normally would just 8913 * write the extents that changed, which is a problem if we need to 8914 * first truncate that entire inode. So set this flag so we write out 8915 * all of the extents in the inode to the sync log so we're completely 8916 * safe. 8917 */ 8918 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 8919 trans->block_rsv = rsv; 8920 8921 while (1) { 8922 ret = btrfs_truncate_inode_items(trans, root, inode, 8923 inode->i_size, 8924 BTRFS_EXTENT_DATA_KEY); 8925 if (ret != -ENOSPC && ret != -EAGAIN) { 8926 err = ret; 8927 break; 8928 } 8929 8930 trans->block_rsv = &root->fs_info->trans_block_rsv; 8931 ret = btrfs_update_inode(trans, root, inode); 8932 if (ret) { 8933 err = ret; 8934 break; 8935 } 8936 8937 btrfs_end_transaction(trans, root); 8938 btrfs_btree_balance_dirty(root); 8939 8940 trans = btrfs_start_transaction(root, 2); 8941 if (IS_ERR(trans)) { 8942 ret = err = PTR_ERR(trans); 8943 trans = NULL; 8944 break; 8945 } 8946 8947 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, 8948 rsv, min_size); 8949 BUG_ON(ret); /* shouldn't happen */ 8950 trans->block_rsv = rsv; 8951 } 8952 8953 if (ret == 0 && inode->i_nlink > 0) { 8954 trans->block_rsv = root->orphan_block_rsv; 8955 ret = btrfs_orphan_del(trans, inode); 8956 if (ret) 8957 err = ret; 8958 } 8959 8960 if (trans) { 8961 trans->block_rsv = &root->fs_info->trans_block_rsv; 8962 ret = btrfs_update_inode(trans, root, inode); 8963 if (ret && !err) 8964 err = ret; 8965 8966 ret = btrfs_end_transaction(trans, root); 8967 btrfs_btree_balance_dirty(root); 8968 } 8969 8970 out: 8971 btrfs_free_block_rsv(root, rsv); 8972 8973 if (ret && !err) 8974 err = ret; 8975 8976 return err; 8977 } 8978 8979 /* 8980 * create a new subvolume directory/inode (helper for the ioctl). 8981 */ 8982 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 8983 struct btrfs_root *new_root, 8984 struct btrfs_root *parent_root, 8985 u64 new_dirid) 8986 { 8987 struct inode *inode; 8988 int err; 8989 u64 index = 0; 8990 8991 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 8992 new_dirid, new_dirid, 8993 S_IFDIR | (~current_umask() & S_IRWXUGO), 8994 &index); 8995 if (IS_ERR(inode)) 8996 return PTR_ERR(inode); 8997 inode->i_op = &btrfs_dir_inode_operations; 8998 inode->i_fop = &btrfs_dir_file_operations; 8999 9000 set_nlink(inode, 1); 9001 btrfs_i_size_write(inode, 0); 9002 unlock_new_inode(inode); 9003 9004 err = btrfs_subvol_inherit_props(trans, new_root, parent_root); 9005 if (err) 9006 btrfs_err(new_root->fs_info, 9007 "error inheriting subvolume %llu properties: %d", 9008 new_root->root_key.objectid, err); 9009 9010 err = btrfs_update_inode(trans, new_root, inode); 9011 9012 iput(inode); 9013 return err; 9014 } 9015 9016 struct inode *btrfs_alloc_inode(struct super_block *sb) 9017 { 9018 struct btrfs_inode *ei; 9019 struct inode *inode; 9020 9021 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 9022 if (!ei) 9023 return NULL; 9024 9025 ei->root = NULL; 9026 ei->generation = 0; 9027 ei->last_trans = 0; 9028 ei->last_sub_trans = 0; 9029 ei->logged_trans = 0; 9030 ei->delalloc_bytes = 0; 9031 ei->defrag_bytes = 0; 9032 ei->disk_i_size = 0; 9033 ei->flags = 0; 9034 ei->csum_bytes = 0; 9035 ei->index_cnt = (u64)-1; 9036 ei->dir_index = 0; 9037 ei->last_unlink_trans = 0; 9038 ei->last_log_commit = 0; 9039 ei->delayed_iput_count = 0; 9040 9041 spin_lock_init(&ei->lock); 9042 ei->outstanding_extents = 0; 9043 ei->reserved_extents = 0; 9044 9045 ei->runtime_flags = 0; 9046 ei->force_compress = BTRFS_COMPRESS_NONE; 9047 9048 ei->delayed_node = NULL; 9049 9050 ei->i_otime.tv_sec = 0; 9051 ei->i_otime.tv_nsec = 0; 9052 9053 inode = &ei->vfs_inode; 9054 extent_map_tree_init(&ei->extent_tree); 9055 extent_io_tree_init(&ei->io_tree, &inode->i_data); 9056 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 9057 ei->io_tree.track_uptodate = 1; 9058 ei->io_failure_tree.track_uptodate = 1; 9059 atomic_set(&ei->sync_writers, 0); 9060 mutex_init(&ei->log_mutex); 9061 mutex_init(&ei->delalloc_mutex); 9062 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 9063 INIT_LIST_HEAD(&ei->delalloc_inodes); 9064 INIT_LIST_HEAD(&ei->delayed_iput); 9065 RB_CLEAR_NODE(&ei->rb_node); 9066 9067 return inode; 9068 } 9069 9070 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 9071 void btrfs_test_destroy_inode(struct inode *inode) 9072 { 9073 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 9074 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 9075 } 9076 #endif 9077 9078 static void btrfs_i_callback(struct rcu_head *head) 9079 { 9080 struct inode *inode = container_of(head, struct inode, i_rcu); 9081 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 9082 } 9083 9084 void btrfs_destroy_inode(struct inode *inode) 9085 { 9086 struct btrfs_ordered_extent *ordered; 9087 struct btrfs_root *root = BTRFS_I(inode)->root; 9088 9089 WARN_ON(!hlist_empty(&inode->i_dentry)); 9090 WARN_ON(inode->i_data.nrpages); 9091 WARN_ON(BTRFS_I(inode)->outstanding_extents); 9092 WARN_ON(BTRFS_I(inode)->reserved_extents); 9093 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 9094 WARN_ON(BTRFS_I(inode)->csum_bytes); 9095 WARN_ON(BTRFS_I(inode)->defrag_bytes); 9096 9097 /* 9098 * This can happen where we create an inode, but somebody else also 9099 * created the same inode and we need to destroy the one we already 9100 * created. 9101 */ 9102 if (!root) 9103 goto free; 9104 9105 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 9106 &BTRFS_I(inode)->runtime_flags)) { 9107 btrfs_info(root->fs_info, "inode %llu still on the orphan list", 9108 btrfs_ino(inode)); 9109 atomic_dec(&root->orphan_inodes); 9110 } 9111 9112 while (1) { 9113 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 9114 if (!ordered) 9115 break; 9116 else { 9117 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", 9118 ordered->file_offset, ordered->len); 9119 btrfs_remove_ordered_extent(inode, ordered); 9120 btrfs_put_ordered_extent(ordered); 9121 btrfs_put_ordered_extent(ordered); 9122 } 9123 } 9124 btrfs_qgroup_check_reserved_leak(inode); 9125 inode_tree_del(inode); 9126 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 9127 free: 9128 call_rcu(&inode->i_rcu, btrfs_i_callback); 9129 } 9130 9131 int btrfs_drop_inode(struct inode *inode) 9132 { 9133 struct btrfs_root *root = BTRFS_I(inode)->root; 9134 9135 if (root == NULL) 9136 return 1; 9137 9138 /* the snap/subvol tree is on deleting */ 9139 if (btrfs_root_refs(&root->root_item) == 0) 9140 return 1; 9141 else 9142 return generic_drop_inode(inode); 9143 } 9144 9145 static void init_once(void *foo) 9146 { 9147 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 9148 9149 inode_init_once(&ei->vfs_inode); 9150 } 9151 9152 void btrfs_destroy_cachep(void) 9153 { 9154 /* 9155 * Make sure all delayed rcu free inodes are flushed before we 9156 * destroy cache. 9157 */ 9158 rcu_barrier(); 9159 if (btrfs_inode_cachep) 9160 kmem_cache_destroy(btrfs_inode_cachep); 9161 if (btrfs_trans_handle_cachep) 9162 kmem_cache_destroy(btrfs_trans_handle_cachep); 9163 if (btrfs_transaction_cachep) 9164 kmem_cache_destroy(btrfs_transaction_cachep); 9165 if (btrfs_path_cachep) 9166 kmem_cache_destroy(btrfs_path_cachep); 9167 if (btrfs_free_space_cachep) 9168 kmem_cache_destroy(btrfs_free_space_cachep); 9169 } 9170 9171 int btrfs_init_cachep(void) 9172 { 9173 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 9174 sizeof(struct btrfs_inode), 0, 9175 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT, 9176 init_once); 9177 if (!btrfs_inode_cachep) 9178 goto fail; 9179 9180 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 9181 sizeof(struct btrfs_trans_handle), 0, 9182 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 9183 if (!btrfs_trans_handle_cachep) 9184 goto fail; 9185 9186 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 9187 sizeof(struct btrfs_transaction), 0, 9188 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 9189 if (!btrfs_transaction_cachep) 9190 goto fail; 9191 9192 btrfs_path_cachep = kmem_cache_create("btrfs_path", 9193 sizeof(struct btrfs_path), 0, 9194 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 9195 if (!btrfs_path_cachep) 9196 goto fail; 9197 9198 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 9199 sizeof(struct btrfs_free_space), 0, 9200 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 9201 if (!btrfs_free_space_cachep) 9202 goto fail; 9203 9204 return 0; 9205 fail: 9206 btrfs_destroy_cachep(); 9207 return -ENOMEM; 9208 } 9209 9210 static int btrfs_getattr(struct vfsmount *mnt, 9211 struct dentry *dentry, struct kstat *stat) 9212 { 9213 u64 delalloc_bytes; 9214 struct inode *inode = d_inode(dentry); 9215 u32 blocksize = inode->i_sb->s_blocksize; 9216 9217 generic_fillattr(inode, stat); 9218 stat->dev = BTRFS_I(inode)->root->anon_dev; 9219 stat->blksize = PAGE_CACHE_SIZE; 9220 9221 spin_lock(&BTRFS_I(inode)->lock); 9222 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 9223 spin_unlock(&BTRFS_I(inode)->lock); 9224 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 9225 ALIGN(delalloc_bytes, blocksize)) >> 9; 9226 return 0; 9227 } 9228 9229 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 9230 struct inode *new_dir, struct dentry *new_dentry) 9231 { 9232 struct btrfs_trans_handle *trans; 9233 struct btrfs_root *root = BTRFS_I(old_dir)->root; 9234 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 9235 struct inode *new_inode = d_inode(new_dentry); 9236 struct inode *old_inode = d_inode(old_dentry); 9237 struct timespec ctime = CURRENT_TIME; 9238 u64 index = 0; 9239 u64 root_objectid; 9240 int ret; 9241 u64 old_ino = btrfs_ino(old_inode); 9242 9243 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 9244 return -EPERM; 9245 9246 /* we only allow rename subvolume link between subvolumes */ 9247 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 9248 return -EXDEV; 9249 9250 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 9251 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) 9252 return -ENOTEMPTY; 9253 9254 if (S_ISDIR(old_inode->i_mode) && new_inode && 9255 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 9256 return -ENOTEMPTY; 9257 9258 9259 /* check for collisions, even if the name isn't there */ 9260 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, 9261 new_dentry->d_name.name, 9262 new_dentry->d_name.len); 9263 9264 if (ret) { 9265 if (ret == -EEXIST) { 9266 /* we shouldn't get 9267 * eexist without a new_inode */ 9268 if (WARN_ON(!new_inode)) { 9269 return ret; 9270 } 9271 } else { 9272 /* maybe -EOVERFLOW */ 9273 return ret; 9274 } 9275 } 9276 ret = 0; 9277 9278 /* 9279 * we're using rename to replace one file with another. Start IO on it 9280 * now so we don't add too much work to the end of the transaction 9281 */ 9282 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size) 9283 filemap_flush(old_inode->i_mapping); 9284 9285 /* close the racy window with snapshot create/destroy ioctl */ 9286 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9287 down_read(&root->fs_info->subvol_sem); 9288 /* 9289 * We want to reserve the absolute worst case amount of items. So if 9290 * both inodes are subvols and we need to unlink them then that would 9291 * require 4 item modifications, but if they are both normal inodes it 9292 * would require 5 item modifications, so we'll assume their normal 9293 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 9294 * should cover the worst case number of items we'll modify. 9295 */ 9296 trans = btrfs_start_transaction(root, 11); 9297 if (IS_ERR(trans)) { 9298 ret = PTR_ERR(trans); 9299 goto out_notrans; 9300 } 9301 9302 if (dest != root) 9303 btrfs_record_root_in_trans(trans, dest); 9304 9305 ret = btrfs_set_inode_index(new_dir, &index); 9306 if (ret) 9307 goto out_fail; 9308 9309 BTRFS_I(old_inode)->dir_index = 0ULL; 9310 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 9311 /* force full log commit if subvolume involved. */ 9312 btrfs_set_log_full_commit(root->fs_info, trans); 9313 } else { 9314 ret = btrfs_insert_inode_ref(trans, dest, 9315 new_dentry->d_name.name, 9316 new_dentry->d_name.len, 9317 old_ino, 9318 btrfs_ino(new_dir), index); 9319 if (ret) 9320 goto out_fail; 9321 /* 9322 * this is an ugly little race, but the rename is required 9323 * to make sure that if we crash, the inode is either at the 9324 * old name or the new one. pinning the log transaction lets 9325 * us make sure we don't allow a log commit to come in after 9326 * we unlink the name but before we add the new name back in. 9327 */ 9328 btrfs_pin_log_trans(root); 9329 } 9330 9331 inode_inc_iversion(old_dir); 9332 inode_inc_iversion(new_dir); 9333 inode_inc_iversion(old_inode); 9334 old_dir->i_ctime = old_dir->i_mtime = ctime; 9335 new_dir->i_ctime = new_dir->i_mtime = ctime; 9336 old_inode->i_ctime = ctime; 9337 9338 if (old_dentry->d_parent != new_dentry->d_parent) 9339 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); 9340 9341 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 9342 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 9343 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 9344 old_dentry->d_name.name, 9345 old_dentry->d_name.len); 9346 } else { 9347 ret = __btrfs_unlink_inode(trans, root, old_dir, 9348 d_inode(old_dentry), 9349 old_dentry->d_name.name, 9350 old_dentry->d_name.len); 9351 if (!ret) 9352 ret = btrfs_update_inode(trans, root, old_inode); 9353 } 9354 if (ret) { 9355 btrfs_abort_transaction(trans, root, ret); 9356 goto out_fail; 9357 } 9358 9359 if (new_inode) { 9360 inode_inc_iversion(new_inode); 9361 new_inode->i_ctime = CURRENT_TIME; 9362 if (unlikely(btrfs_ino(new_inode) == 9363 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 9364 root_objectid = BTRFS_I(new_inode)->location.objectid; 9365 ret = btrfs_unlink_subvol(trans, dest, new_dir, 9366 root_objectid, 9367 new_dentry->d_name.name, 9368 new_dentry->d_name.len); 9369 BUG_ON(new_inode->i_nlink == 0); 9370 } else { 9371 ret = btrfs_unlink_inode(trans, dest, new_dir, 9372 d_inode(new_dentry), 9373 new_dentry->d_name.name, 9374 new_dentry->d_name.len); 9375 } 9376 if (!ret && new_inode->i_nlink == 0) 9377 ret = btrfs_orphan_add(trans, d_inode(new_dentry)); 9378 if (ret) { 9379 btrfs_abort_transaction(trans, root, ret); 9380 goto out_fail; 9381 } 9382 } 9383 9384 ret = btrfs_add_link(trans, new_dir, old_inode, 9385 new_dentry->d_name.name, 9386 new_dentry->d_name.len, 0, index); 9387 if (ret) { 9388 btrfs_abort_transaction(trans, root, ret); 9389 goto out_fail; 9390 } 9391 9392 if (old_inode->i_nlink == 1) 9393 BTRFS_I(old_inode)->dir_index = index; 9394 9395 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { 9396 struct dentry *parent = new_dentry->d_parent; 9397 btrfs_log_new_name(trans, old_inode, old_dir, parent); 9398 btrfs_end_log_trans(root); 9399 } 9400 out_fail: 9401 btrfs_end_transaction(trans, root); 9402 out_notrans: 9403 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9404 up_read(&root->fs_info->subvol_sem); 9405 9406 return ret; 9407 } 9408 9409 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, 9410 struct inode *new_dir, struct dentry *new_dentry, 9411 unsigned int flags) 9412 { 9413 if (flags & ~RENAME_NOREPLACE) 9414 return -EINVAL; 9415 9416 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry); 9417 } 9418 9419 static void btrfs_run_delalloc_work(struct btrfs_work *work) 9420 { 9421 struct btrfs_delalloc_work *delalloc_work; 9422 struct inode *inode; 9423 9424 delalloc_work = container_of(work, struct btrfs_delalloc_work, 9425 work); 9426 inode = delalloc_work->inode; 9427 filemap_flush(inode->i_mapping); 9428 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 9429 &BTRFS_I(inode)->runtime_flags)) 9430 filemap_flush(inode->i_mapping); 9431 9432 if (delalloc_work->delay_iput) 9433 btrfs_add_delayed_iput(inode); 9434 else 9435 iput(inode); 9436 complete(&delalloc_work->completion); 9437 } 9438 9439 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 9440 int delay_iput) 9441 { 9442 struct btrfs_delalloc_work *work; 9443 9444 work = kmalloc(sizeof(*work), GFP_NOFS); 9445 if (!work) 9446 return NULL; 9447 9448 init_completion(&work->completion); 9449 INIT_LIST_HEAD(&work->list); 9450 work->inode = inode; 9451 work->delay_iput = delay_iput; 9452 WARN_ON_ONCE(!inode); 9453 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper, 9454 btrfs_run_delalloc_work, NULL, NULL); 9455 9456 return work; 9457 } 9458 9459 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 9460 { 9461 wait_for_completion(&work->completion); 9462 kfree(work); 9463 } 9464 9465 /* 9466 * some fairly slow code that needs optimization. This walks the list 9467 * of all the inodes with pending delalloc and forces them to disk. 9468 */ 9469 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput, 9470 int nr) 9471 { 9472 struct btrfs_inode *binode; 9473 struct inode *inode; 9474 struct btrfs_delalloc_work *work, *next; 9475 struct list_head works; 9476 struct list_head splice; 9477 int ret = 0; 9478 9479 INIT_LIST_HEAD(&works); 9480 INIT_LIST_HEAD(&splice); 9481 9482 mutex_lock(&root->delalloc_mutex); 9483 spin_lock(&root->delalloc_lock); 9484 list_splice_init(&root->delalloc_inodes, &splice); 9485 while (!list_empty(&splice)) { 9486 binode = list_entry(splice.next, struct btrfs_inode, 9487 delalloc_inodes); 9488 9489 list_move_tail(&binode->delalloc_inodes, 9490 &root->delalloc_inodes); 9491 inode = igrab(&binode->vfs_inode); 9492 if (!inode) { 9493 cond_resched_lock(&root->delalloc_lock); 9494 continue; 9495 } 9496 spin_unlock(&root->delalloc_lock); 9497 9498 work = btrfs_alloc_delalloc_work(inode, delay_iput); 9499 if (!work) { 9500 if (delay_iput) 9501 btrfs_add_delayed_iput(inode); 9502 else 9503 iput(inode); 9504 ret = -ENOMEM; 9505 goto out; 9506 } 9507 list_add_tail(&work->list, &works); 9508 btrfs_queue_work(root->fs_info->flush_workers, 9509 &work->work); 9510 ret++; 9511 if (nr != -1 && ret >= nr) 9512 goto out; 9513 cond_resched(); 9514 spin_lock(&root->delalloc_lock); 9515 } 9516 spin_unlock(&root->delalloc_lock); 9517 9518 out: 9519 list_for_each_entry_safe(work, next, &works, list) { 9520 list_del_init(&work->list); 9521 btrfs_wait_and_free_delalloc_work(work); 9522 } 9523 9524 if (!list_empty_careful(&splice)) { 9525 spin_lock(&root->delalloc_lock); 9526 list_splice_tail(&splice, &root->delalloc_inodes); 9527 spin_unlock(&root->delalloc_lock); 9528 } 9529 mutex_unlock(&root->delalloc_mutex); 9530 return ret; 9531 } 9532 9533 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 9534 { 9535 int ret; 9536 9537 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 9538 return -EROFS; 9539 9540 ret = __start_delalloc_inodes(root, delay_iput, -1); 9541 if (ret > 0) 9542 ret = 0; 9543 /* 9544 * the filemap_flush will queue IO into the worker threads, but 9545 * we have to make sure the IO is actually started and that 9546 * ordered extents get created before we return 9547 */ 9548 atomic_inc(&root->fs_info->async_submit_draining); 9549 while (atomic_read(&root->fs_info->nr_async_submits) || 9550 atomic_read(&root->fs_info->async_delalloc_pages)) { 9551 wait_event(root->fs_info->async_submit_wait, 9552 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 9553 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 9554 } 9555 atomic_dec(&root->fs_info->async_submit_draining); 9556 return ret; 9557 } 9558 9559 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput, 9560 int nr) 9561 { 9562 struct btrfs_root *root; 9563 struct list_head splice; 9564 int ret; 9565 9566 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 9567 return -EROFS; 9568 9569 INIT_LIST_HEAD(&splice); 9570 9571 mutex_lock(&fs_info->delalloc_root_mutex); 9572 spin_lock(&fs_info->delalloc_root_lock); 9573 list_splice_init(&fs_info->delalloc_roots, &splice); 9574 while (!list_empty(&splice) && nr) { 9575 root = list_first_entry(&splice, struct btrfs_root, 9576 delalloc_root); 9577 root = btrfs_grab_fs_root(root); 9578 BUG_ON(!root); 9579 list_move_tail(&root->delalloc_root, 9580 &fs_info->delalloc_roots); 9581 spin_unlock(&fs_info->delalloc_root_lock); 9582 9583 ret = __start_delalloc_inodes(root, delay_iput, nr); 9584 btrfs_put_fs_root(root); 9585 if (ret < 0) 9586 goto out; 9587 9588 if (nr != -1) { 9589 nr -= ret; 9590 WARN_ON(nr < 0); 9591 } 9592 spin_lock(&fs_info->delalloc_root_lock); 9593 } 9594 spin_unlock(&fs_info->delalloc_root_lock); 9595 9596 ret = 0; 9597 atomic_inc(&fs_info->async_submit_draining); 9598 while (atomic_read(&fs_info->nr_async_submits) || 9599 atomic_read(&fs_info->async_delalloc_pages)) { 9600 wait_event(fs_info->async_submit_wait, 9601 (atomic_read(&fs_info->nr_async_submits) == 0 && 9602 atomic_read(&fs_info->async_delalloc_pages) == 0)); 9603 } 9604 atomic_dec(&fs_info->async_submit_draining); 9605 out: 9606 if (!list_empty_careful(&splice)) { 9607 spin_lock(&fs_info->delalloc_root_lock); 9608 list_splice_tail(&splice, &fs_info->delalloc_roots); 9609 spin_unlock(&fs_info->delalloc_root_lock); 9610 } 9611 mutex_unlock(&fs_info->delalloc_root_mutex); 9612 return ret; 9613 } 9614 9615 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 9616 const char *symname) 9617 { 9618 struct btrfs_trans_handle *trans; 9619 struct btrfs_root *root = BTRFS_I(dir)->root; 9620 struct btrfs_path *path; 9621 struct btrfs_key key; 9622 struct inode *inode = NULL; 9623 int err; 9624 int drop_inode = 0; 9625 u64 objectid; 9626 u64 index = 0; 9627 int name_len; 9628 int datasize; 9629 unsigned long ptr; 9630 struct btrfs_file_extent_item *ei; 9631 struct extent_buffer *leaf; 9632 9633 name_len = strlen(symname); 9634 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) 9635 return -ENAMETOOLONG; 9636 9637 /* 9638 * 2 items for inode item and ref 9639 * 2 items for dir items 9640 * 1 item for updating parent inode item 9641 * 1 item for the inline extent item 9642 * 1 item for xattr if selinux is on 9643 */ 9644 trans = btrfs_start_transaction(root, 7); 9645 if (IS_ERR(trans)) 9646 return PTR_ERR(trans); 9647 9648 err = btrfs_find_free_ino(root, &objectid); 9649 if (err) 9650 goto out_unlock; 9651 9652 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 9653 dentry->d_name.len, btrfs_ino(dir), objectid, 9654 S_IFLNK|S_IRWXUGO, &index); 9655 if (IS_ERR(inode)) { 9656 err = PTR_ERR(inode); 9657 goto out_unlock; 9658 } 9659 9660 /* 9661 * If the active LSM wants to access the inode during 9662 * d_instantiate it needs these. Smack checks to see 9663 * if the filesystem supports xattrs by looking at the 9664 * ops vector. 9665 */ 9666 inode->i_fop = &btrfs_file_operations; 9667 inode->i_op = &btrfs_file_inode_operations; 9668 inode->i_mapping->a_ops = &btrfs_aops; 9669 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 9670 9671 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 9672 if (err) 9673 goto out_unlock_inode; 9674 9675 path = btrfs_alloc_path(); 9676 if (!path) { 9677 err = -ENOMEM; 9678 goto out_unlock_inode; 9679 } 9680 key.objectid = btrfs_ino(inode); 9681 key.offset = 0; 9682 key.type = BTRFS_EXTENT_DATA_KEY; 9683 datasize = btrfs_file_extent_calc_inline_size(name_len); 9684 err = btrfs_insert_empty_item(trans, root, path, &key, 9685 datasize); 9686 if (err) { 9687 btrfs_free_path(path); 9688 goto out_unlock_inode; 9689 } 9690 leaf = path->nodes[0]; 9691 ei = btrfs_item_ptr(leaf, path->slots[0], 9692 struct btrfs_file_extent_item); 9693 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 9694 btrfs_set_file_extent_type(leaf, ei, 9695 BTRFS_FILE_EXTENT_INLINE); 9696 btrfs_set_file_extent_encryption(leaf, ei, 0); 9697 btrfs_set_file_extent_compression(leaf, ei, 0); 9698 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 9699 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 9700 9701 ptr = btrfs_file_extent_inline_start(ei); 9702 write_extent_buffer(leaf, symname, ptr, name_len); 9703 btrfs_mark_buffer_dirty(leaf); 9704 btrfs_free_path(path); 9705 9706 inode->i_op = &btrfs_symlink_inode_operations; 9707 inode_nohighmem(inode); 9708 inode->i_mapping->a_ops = &btrfs_symlink_aops; 9709 inode_set_bytes(inode, name_len); 9710 btrfs_i_size_write(inode, name_len); 9711 err = btrfs_update_inode(trans, root, inode); 9712 /* 9713 * Last step, add directory indexes for our symlink inode. This is the 9714 * last step to avoid extra cleanup of these indexes if an error happens 9715 * elsewhere above. 9716 */ 9717 if (!err) 9718 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 9719 if (err) { 9720 drop_inode = 1; 9721 goto out_unlock_inode; 9722 } 9723 9724 unlock_new_inode(inode); 9725 d_instantiate(dentry, inode); 9726 9727 out_unlock: 9728 btrfs_end_transaction(trans, root); 9729 if (drop_inode) { 9730 inode_dec_link_count(inode); 9731 iput(inode); 9732 } 9733 btrfs_btree_balance_dirty(root); 9734 return err; 9735 9736 out_unlock_inode: 9737 drop_inode = 1; 9738 unlock_new_inode(inode); 9739 goto out_unlock; 9740 } 9741 9742 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 9743 u64 start, u64 num_bytes, u64 min_size, 9744 loff_t actual_len, u64 *alloc_hint, 9745 struct btrfs_trans_handle *trans) 9746 { 9747 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 9748 struct extent_map *em; 9749 struct btrfs_root *root = BTRFS_I(inode)->root; 9750 struct btrfs_key ins; 9751 u64 cur_offset = start; 9752 u64 i_size; 9753 u64 cur_bytes; 9754 u64 last_alloc = (u64)-1; 9755 int ret = 0; 9756 bool own_trans = true; 9757 9758 if (trans) 9759 own_trans = false; 9760 while (num_bytes > 0) { 9761 if (own_trans) { 9762 trans = btrfs_start_transaction(root, 3); 9763 if (IS_ERR(trans)) { 9764 ret = PTR_ERR(trans); 9765 break; 9766 } 9767 } 9768 9769 cur_bytes = min_t(u64, num_bytes, SZ_256M); 9770 cur_bytes = max(cur_bytes, min_size); 9771 /* 9772 * If we are severely fragmented we could end up with really 9773 * small allocations, so if the allocator is returning small 9774 * chunks lets make its job easier by only searching for those 9775 * sized chunks. 9776 */ 9777 cur_bytes = min(cur_bytes, last_alloc); 9778 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0, 9779 *alloc_hint, &ins, 1, 0); 9780 if (ret) { 9781 if (own_trans) 9782 btrfs_end_transaction(trans, root); 9783 break; 9784 } 9785 9786 last_alloc = ins.offset; 9787 ret = insert_reserved_file_extent(trans, inode, 9788 cur_offset, ins.objectid, 9789 ins.offset, ins.offset, 9790 ins.offset, 0, 0, 0, 9791 BTRFS_FILE_EXTENT_PREALLOC); 9792 if (ret) { 9793 btrfs_free_reserved_extent(root, ins.objectid, 9794 ins.offset, 0); 9795 btrfs_abort_transaction(trans, root, ret); 9796 if (own_trans) 9797 btrfs_end_transaction(trans, root); 9798 break; 9799 } 9800 9801 btrfs_drop_extent_cache(inode, cur_offset, 9802 cur_offset + ins.offset -1, 0); 9803 9804 em = alloc_extent_map(); 9805 if (!em) { 9806 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 9807 &BTRFS_I(inode)->runtime_flags); 9808 goto next; 9809 } 9810 9811 em->start = cur_offset; 9812 em->orig_start = cur_offset; 9813 em->len = ins.offset; 9814 em->block_start = ins.objectid; 9815 em->block_len = ins.offset; 9816 em->orig_block_len = ins.offset; 9817 em->ram_bytes = ins.offset; 9818 em->bdev = root->fs_info->fs_devices->latest_bdev; 9819 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 9820 em->generation = trans->transid; 9821 9822 while (1) { 9823 write_lock(&em_tree->lock); 9824 ret = add_extent_mapping(em_tree, em, 1); 9825 write_unlock(&em_tree->lock); 9826 if (ret != -EEXIST) 9827 break; 9828 btrfs_drop_extent_cache(inode, cur_offset, 9829 cur_offset + ins.offset - 1, 9830 0); 9831 } 9832 free_extent_map(em); 9833 next: 9834 num_bytes -= ins.offset; 9835 cur_offset += ins.offset; 9836 *alloc_hint = ins.objectid + ins.offset; 9837 9838 inode_inc_iversion(inode); 9839 inode->i_ctime = CURRENT_TIME; 9840 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 9841 if (!(mode & FALLOC_FL_KEEP_SIZE) && 9842 (actual_len > inode->i_size) && 9843 (cur_offset > inode->i_size)) { 9844 if (cur_offset > actual_len) 9845 i_size = actual_len; 9846 else 9847 i_size = cur_offset; 9848 i_size_write(inode, i_size); 9849 btrfs_ordered_update_i_size(inode, i_size, NULL); 9850 } 9851 9852 ret = btrfs_update_inode(trans, root, inode); 9853 9854 if (ret) { 9855 btrfs_abort_transaction(trans, root, ret); 9856 if (own_trans) 9857 btrfs_end_transaction(trans, root); 9858 break; 9859 } 9860 9861 if (own_trans) 9862 btrfs_end_transaction(trans, root); 9863 } 9864 return ret; 9865 } 9866 9867 int btrfs_prealloc_file_range(struct inode *inode, int mode, 9868 u64 start, u64 num_bytes, u64 min_size, 9869 loff_t actual_len, u64 *alloc_hint) 9870 { 9871 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 9872 min_size, actual_len, alloc_hint, 9873 NULL); 9874 } 9875 9876 int btrfs_prealloc_file_range_trans(struct inode *inode, 9877 struct btrfs_trans_handle *trans, int mode, 9878 u64 start, u64 num_bytes, u64 min_size, 9879 loff_t actual_len, u64 *alloc_hint) 9880 { 9881 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 9882 min_size, actual_len, alloc_hint, trans); 9883 } 9884 9885 static int btrfs_set_page_dirty(struct page *page) 9886 { 9887 return __set_page_dirty_nobuffers(page); 9888 } 9889 9890 static int btrfs_permission(struct inode *inode, int mask) 9891 { 9892 struct btrfs_root *root = BTRFS_I(inode)->root; 9893 umode_t mode = inode->i_mode; 9894 9895 if (mask & MAY_WRITE && 9896 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 9897 if (btrfs_root_readonly(root)) 9898 return -EROFS; 9899 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 9900 return -EACCES; 9901 } 9902 return generic_permission(inode, mask); 9903 } 9904 9905 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 9906 { 9907 struct btrfs_trans_handle *trans; 9908 struct btrfs_root *root = BTRFS_I(dir)->root; 9909 struct inode *inode = NULL; 9910 u64 objectid; 9911 u64 index; 9912 int ret = 0; 9913 9914 /* 9915 * 5 units required for adding orphan entry 9916 */ 9917 trans = btrfs_start_transaction(root, 5); 9918 if (IS_ERR(trans)) 9919 return PTR_ERR(trans); 9920 9921 ret = btrfs_find_free_ino(root, &objectid); 9922 if (ret) 9923 goto out; 9924 9925 inode = btrfs_new_inode(trans, root, dir, NULL, 0, 9926 btrfs_ino(dir), objectid, mode, &index); 9927 if (IS_ERR(inode)) { 9928 ret = PTR_ERR(inode); 9929 inode = NULL; 9930 goto out; 9931 } 9932 9933 inode->i_fop = &btrfs_file_operations; 9934 inode->i_op = &btrfs_file_inode_operations; 9935 9936 inode->i_mapping->a_ops = &btrfs_aops; 9937 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 9938 9939 ret = btrfs_init_inode_security(trans, inode, dir, NULL); 9940 if (ret) 9941 goto out_inode; 9942 9943 ret = btrfs_update_inode(trans, root, inode); 9944 if (ret) 9945 goto out_inode; 9946 ret = btrfs_orphan_add(trans, inode); 9947 if (ret) 9948 goto out_inode; 9949 9950 /* 9951 * We set number of links to 0 in btrfs_new_inode(), and here we set 9952 * it to 1 because d_tmpfile() will issue a warning if the count is 0, 9953 * through: 9954 * 9955 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink() 9956 */ 9957 set_nlink(inode, 1); 9958 unlock_new_inode(inode); 9959 d_tmpfile(dentry, inode); 9960 mark_inode_dirty(inode); 9961 9962 out: 9963 btrfs_end_transaction(trans, root); 9964 if (ret) 9965 iput(inode); 9966 btrfs_balance_delayed_items(root); 9967 btrfs_btree_balance_dirty(root); 9968 return ret; 9969 9970 out_inode: 9971 unlock_new_inode(inode); 9972 goto out; 9973 9974 } 9975 9976 /* Inspired by filemap_check_errors() */ 9977 int btrfs_inode_check_errors(struct inode *inode) 9978 { 9979 int ret = 0; 9980 9981 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) && 9982 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags)) 9983 ret = -ENOSPC; 9984 if (test_bit(AS_EIO, &inode->i_mapping->flags) && 9985 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags)) 9986 ret = -EIO; 9987 9988 return ret; 9989 } 9990 9991 static const struct inode_operations btrfs_dir_inode_operations = { 9992 .getattr = btrfs_getattr, 9993 .lookup = btrfs_lookup, 9994 .create = btrfs_create, 9995 .unlink = btrfs_unlink, 9996 .link = btrfs_link, 9997 .mkdir = btrfs_mkdir, 9998 .rmdir = btrfs_rmdir, 9999 .rename2 = btrfs_rename2, 10000 .symlink = btrfs_symlink, 10001 .setattr = btrfs_setattr, 10002 .mknod = btrfs_mknod, 10003 .setxattr = btrfs_setxattr, 10004 .getxattr = generic_getxattr, 10005 .listxattr = btrfs_listxattr, 10006 .removexattr = btrfs_removexattr, 10007 .permission = btrfs_permission, 10008 .get_acl = btrfs_get_acl, 10009 .set_acl = btrfs_set_acl, 10010 .update_time = btrfs_update_time, 10011 .tmpfile = btrfs_tmpfile, 10012 }; 10013 static const struct inode_operations btrfs_dir_ro_inode_operations = { 10014 .lookup = btrfs_lookup, 10015 .permission = btrfs_permission, 10016 .get_acl = btrfs_get_acl, 10017 .set_acl = btrfs_set_acl, 10018 .update_time = btrfs_update_time, 10019 }; 10020 10021 static const struct file_operations btrfs_dir_file_operations = { 10022 .llseek = generic_file_llseek, 10023 .read = generic_read_dir, 10024 .iterate = btrfs_real_readdir, 10025 .unlocked_ioctl = btrfs_ioctl, 10026 #ifdef CONFIG_COMPAT 10027 .compat_ioctl = btrfs_ioctl, 10028 #endif 10029 .release = btrfs_release_file, 10030 .fsync = btrfs_sync_file, 10031 }; 10032 10033 static const struct extent_io_ops btrfs_extent_io_ops = { 10034 .fill_delalloc = run_delalloc_range, 10035 .submit_bio_hook = btrfs_submit_bio_hook, 10036 .merge_bio_hook = btrfs_merge_bio_hook, 10037 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 10038 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 10039 .writepage_start_hook = btrfs_writepage_start_hook, 10040 .set_bit_hook = btrfs_set_bit_hook, 10041 .clear_bit_hook = btrfs_clear_bit_hook, 10042 .merge_extent_hook = btrfs_merge_extent_hook, 10043 .split_extent_hook = btrfs_split_extent_hook, 10044 }; 10045 10046 /* 10047 * btrfs doesn't support the bmap operation because swapfiles 10048 * use bmap to make a mapping of extents in the file. They assume 10049 * these extents won't change over the life of the file and they 10050 * use the bmap result to do IO directly to the drive. 10051 * 10052 * the btrfs bmap call would return logical addresses that aren't 10053 * suitable for IO and they also will change frequently as COW 10054 * operations happen. So, swapfile + btrfs == corruption. 10055 * 10056 * For now we're avoiding this by dropping bmap. 10057 */ 10058 static const struct address_space_operations btrfs_aops = { 10059 .readpage = btrfs_readpage, 10060 .writepage = btrfs_writepage, 10061 .writepages = btrfs_writepages, 10062 .readpages = btrfs_readpages, 10063 .direct_IO = btrfs_direct_IO, 10064 .invalidatepage = btrfs_invalidatepage, 10065 .releasepage = btrfs_releasepage, 10066 .set_page_dirty = btrfs_set_page_dirty, 10067 .error_remove_page = generic_error_remove_page, 10068 }; 10069 10070 static const struct address_space_operations btrfs_symlink_aops = { 10071 .readpage = btrfs_readpage, 10072 .writepage = btrfs_writepage, 10073 .invalidatepage = btrfs_invalidatepage, 10074 .releasepage = btrfs_releasepage, 10075 }; 10076 10077 static const struct inode_operations btrfs_file_inode_operations = { 10078 .getattr = btrfs_getattr, 10079 .setattr = btrfs_setattr, 10080 .setxattr = btrfs_setxattr, 10081 .getxattr = generic_getxattr, 10082 .listxattr = btrfs_listxattr, 10083 .removexattr = btrfs_removexattr, 10084 .permission = btrfs_permission, 10085 .fiemap = btrfs_fiemap, 10086 .get_acl = btrfs_get_acl, 10087 .set_acl = btrfs_set_acl, 10088 .update_time = btrfs_update_time, 10089 }; 10090 static const struct inode_operations btrfs_special_inode_operations = { 10091 .getattr = btrfs_getattr, 10092 .setattr = btrfs_setattr, 10093 .permission = btrfs_permission, 10094 .setxattr = btrfs_setxattr, 10095 .getxattr = generic_getxattr, 10096 .listxattr = btrfs_listxattr, 10097 .removexattr = btrfs_removexattr, 10098 .get_acl = btrfs_get_acl, 10099 .set_acl = btrfs_set_acl, 10100 .update_time = btrfs_update_time, 10101 }; 10102 static const struct inode_operations btrfs_symlink_inode_operations = { 10103 .readlink = generic_readlink, 10104 .get_link = page_get_link, 10105 .getattr = btrfs_getattr, 10106 .setattr = btrfs_setattr, 10107 .permission = btrfs_permission, 10108 .setxattr = btrfs_setxattr, 10109 .getxattr = generic_getxattr, 10110 .listxattr = btrfs_listxattr, 10111 .removexattr = btrfs_removexattr, 10112 .update_time = btrfs_update_time, 10113 }; 10114 10115 const struct dentry_operations btrfs_dentry_operations = { 10116 .d_delete = btrfs_dentry_delete, 10117 .d_release = btrfs_dentry_release, 10118 }; 10119