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/aio.h> 36 #include <linux/bit_spinlock.h> 37 #include <linux/xattr.h> 38 #include <linux/posix_acl.h> 39 #include <linux/falloc.h> 40 #include <linux/slab.h> 41 #include <linux/ratelimit.h> 42 #include <linux/mount.h> 43 #include <linux/btrfs.h> 44 #include <linux/blkdev.h> 45 #include <linux/posix_acl_xattr.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 63 struct btrfs_iget_args { 64 struct btrfs_key *location; 65 struct btrfs_root *root; 66 }; 67 68 static const struct inode_operations btrfs_dir_inode_operations; 69 static const struct inode_operations btrfs_symlink_inode_operations; 70 static const struct inode_operations btrfs_dir_ro_inode_operations; 71 static const struct inode_operations btrfs_special_inode_operations; 72 static const struct inode_operations btrfs_file_inode_operations; 73 static const struct address_space_operations btrfs_aops; 74 static const struct address_space_operations btrfs_symlink_aops; 75 static const struct file_operations btrfs_dir_file_operations; 76 static struct extent_io_ops btrfs_extent_io_ops; 77 78 static struct kmem_cache *btrfs_inode_cachep; 79 static struct kmem_cache *btrfs_delalloc_work_cachep; 80 struct kmem_cache *btrfs_trans_handle_cachep; 81 struct kmem_cache *btrfs_transaction_cachep; 82 struct kmem_cache *btrfs_path_cachep; 83 struct kmem_cache *btrfs_free_space_cachep; 84 85 #define S_SHIFT 12 86 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { 87 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, 88 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, 89 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, 90 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, 91 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, 92 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, 93 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, 94 }; 95 96 static int btrfs_setsize(struct inode *inode, struct iattr *attr); 97 static int btrfs_truncate(struct inode *inode); 98 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); 99 static noinline int cow_file_range(struct inode *inode, 100 struct page *locked_page, 101 u64 start, u64 end, int *page_started, 102 unsigned long *nr_written, int unlock); 103 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 104 u64 len, u64 orig_start, 105 u64 block_start, u64 block_len, 106 u64 orig_block_len, u64 ram_bytes, 107 int type); 108 109 static int btrfs_dirty_inode(struct inode *inode); 110 111 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, 112 struct inode *inode, struct inode *dir, 113 const struct qstr *qstr) 114 { 115 int err; 116 117 err = btrfs_init_acl(trans, inode, dir); 118 if (!err) 119 err = btrfs_xattr_security_init(trans, inode, dir, qstr); 120 return err; 121 } 122 123 /* 124 * this does all the hard work for inserting an inline extent into 125 * the btree. The caller should have done a btrfs_drop_extents so that 126 * no overlapping inline items exist in the btree 127 */ 128 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, 129 struct btrfs_path *path, int extent_inserted, 130 struct btrfs_root *root, struct inode *inode, 131 u64 start, size_t size, size_t compressed_size, 132 int compress_type, 133 struct page **compressed_pages) 134 { 135 struct extent_buffer *leaf; 136 struct page *page = NULL; 137 char *kaddr; 138 unsigned long ptr; 139 struct btrfs_file_extent_item *ei; 140 int err = 0; 141 int ret; 142 size_t cur_size = size; 143 unsigned long offset; 144 145 if (compressed_size && compressed_pages) 146 cur_size = compressed_size; 147 148 inode_add_bytes(inode, size); 149 150 if (!extent_inserted) { 151 struct btrfs_key key; 152 size_t datasize; 153 154 key.objectid = btrfs_ino(inode); 155 key.offset = start; 156 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 157 158 datasize = btrfs_file_extent_calc_inline_size(cur_size); 159 path->leave_spinning = 1; 160 ret = btrfs_insert_empty_item(trans, root, path, &key, 161 datasize); 162 if (ret) { 163 err = ret; 164 goto fail; 165 } 166 } 167 leaf = path->nodes[0]; 168 ei = btrfs_item_ptr(leaf, path->slots[0], 169 struct btrfs_file_extent_item); 170 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 171 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 172 btrfs_set_file_extent_encryption(leaf, ei, 0); 173 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 174 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 175 ptr = btrfs_file_extent_inline_start(ei); 176 177 if (compress_type != BTRFS_COMPRESS_NONE) { 178 struct page *cpage; 179 int i = 0; 180 while (compressed_size > 0) { 181 cpage = compressed_pages[i]; 182 cur_size = min_t(unsigned long, compressed_size, 183 PAGE_CACHE_SIZE); 184 185 kaddr = kmap_atomic(cpage); 186 write_extent_buffer(leaf, kaddr, ptr, cur_size); 187 kunmap_atomic(kaddr); 188 189 i++; 190 ptr += cur_size; 191 compressed_size -= cur_size; 192 } 193 btrfs_set_file_extent_compression(leaf, ei, 194 compress_type); 195 } else { 196 page = find_get_page(inode->i_mapping, 197 start >> PAGE_CACHE_SHIFT); 198 btrfs_set_file_extent_compression(leaf, ei, 0); 199 kaddr = kmap_atomic(page); 200 offset = start & (PAGE_CACHE_SIZE - 1); 201 write_extent_buffer(leaf, kaddr + offset, ptr, size); 202 kunmap_atomic(kaddr); 203 page_cache_release(page); 204 } 205 btrfs_mark_buffer_dirty(leaf); 206 btrfs_release_path(path); 207 208 /* 209 * we're an inline extent, so nobody can 210 * extend the file past i_size without locking 211 * a page we already have locked. 212 * 213 * We must do any isize and inode updates 214 * before we unlock the pages. Otherwise we 215 * could end up racing with unlink. 216 */ 217 BTRFS_I(inode)->disk_i_size = inode->i_size; 218 ret = btrfs_update_inode(trans, root, inode); 219 220 return ret; 221 fail: 222 return err; 223 } 224 225 226 /* 227 * conditionally insert an inline extent into the file. This 228 * does the checks required to make sure the data is small enough 229 * to fit as an inline extent. 230 */ 231 static noinline int cow_file_range_inline(struct btrfs_root *root, 232 struct inode *inode, u64 start, 233 u64 end, size_t compressed_size, 234 int compress_type, 235 struct page **compressed_pages) 236 { 237 struct btrfs_trans_handle *trans; 238 u64 isize = i_size_read(inode); 239 u64 actual_end = min(end + 1, isize); 240 u64 inline_len = actual_end - start; 241 u64 aligned_end = ALIGN(end, root->sectorsize); 242 u64 data_len = inline_len; 243 int ret; 244 struct btrfs_path *path; 245 int extent_inserted = 0; 246 u32 extent_item_size; 247 248 if (compressed_size) 249 data_len = compressed_size; 250 251 if (start > 0 || 252 actual_end >= PAGE_CACHE_SIZE || 253 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || 254 (!compressed_size && 255 (actual_end & (root->sectorsize - 1)) == 0) || 256 end + 1 < isize || 257 data_len > root->fs_info->max_inline) { 258 return 1; 259 } 260 261 path = btrfs_alloc_path(); 262 if (!path) 263 return -ENOMEM; 264 265 trans = btrfs_join_transaction(root); 266 if (IS_ERR(trans)) { 267 btrfs_free_path(path); 268 return PTR_ERR(trans); 269 } 270 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 271 272 if (compressed_size && compressed_pages) 273 extent_item_size = btrfs_file_extent_calc_inline_size( 274 compressed_size); 275 else 276 extent_item_size = btrfs_file_extent_calc_inline_size( 277 inline_len); 278 279 ret = __btrfs_drop_extents(trans, root, inode, path, 280 start, aligned_end, NULL, 281 1, 1, extent_item_size, &extent_inserted); 282 if (ret) { 283 btrfs_abort_transaction(trans, root, ret); 284 goto out; 285 } 286 287 if (isize > actual_end) 288 inline_len = min_t(u64, isize, actual_end); 289 ret = insert_inline_extent(trans, path, extent_inserted, 290 root, inode, start, 291 inline_len, compressed_size, 292 compress_type, compressed_pages); 293 if (ret && ret != -ENOSPC) { 294 btrfs_abort_transaction(trans, root, ret); 295 goto out; 296 } else if (ret == -ENOSPC) { 297 ret = 1; 298 goto out; 299 } 300 301 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 302 btrfs_delalloc_release_metadata(inode, end + 1 - start); 303 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); 304 out: 305 btrfs_free_path(path); 306 btrfs_end_transaction(trans, root); 307 return ret; 308 } 309 310 struct async_extent { 311 u64 start; 312 u64 ram_size; 313 u64 compressed_size; 314 struct page **pages; 315 unsigned long nr_pages; 316 int compress_type; 317 struct list_head list; 318 }; 319 320 struct async_cow { 321 struct inode *inode; 322 struct btrfs_root *root; 323 struct page *locked_page; 324 u64 start; 325 u64 end; 326 struct list_head extents; 327 struct btrfs_work work; 328 }; 329 330 static noinline int add_async_extent(struct async_cow *cow, 331 u64 start, u64 ram_size, 332 u64 compressed_size, 333 struct page **pages, 334 unsigned long nr_pages, 335 int compress_type) 336 { 337 struct async_extent *async_extent; 338 339 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 340 BUG_ON(!async_extent); /* -ENOMEM */ 341 async_extent->start = start; 342 async_extent->ram_size = ram_size; 343 async_extent->compressed_size = compressed_size; 344 async_extent->pages = pages; 345 async_extent->nr_pages = nr_pages; 346 async_extent->compress_type = compress_type; 347 list_add_tail(&async_extent->list, &cow->extents); 348 return 0; 349 } 350 351 /* 352 * we create compressed extents in two phases. The first 353 * phase compresses a range of pages that have already been 354 * locked (both pages and state bits are locked). 355 * 356 * This is done inside an ordered work queue, and the compression 357 * is spread across many cpus. The actual IO submission is step 358 * two, and the ordered work queue takes care of making sure that 359 * happens in the same order things were put onto the queue by 360 * writepages and friends. 361 * 362 * If this code finds it can't get good compression, it puts an 363 * entry onto the work queue to write the uncompressed bytes. This 364 * makes sure that both compressed inodes and uncompressed inodes 365 * are written in the same order that the flusher thread sent them 366 * down. 367 */ 368 static noinline int compress_file_range(struct inode *inode, 369 struct page *locked_page, 370 u64 start, u64 end, 371 struct async_cow *async_cow, 372 int *num_added) 373 { 374 struct btrfs_root *root = BTRFS_I(inode)->root; 375 u64 num_bytes; 376 u64 blocksize = root->sectorsize; 377 u64 actual_end; 378 u64 isize = i_size_read(inode); 379 int ret = 0; 380 struct page **pages = NULL; 381 unsigned long nr_pages; 382 unsigned long nr_pages_ret = 0; 383 unsigned long total_compressed = 0; 384 unsigned long total_in = 0; 385 unsigned long max_compressed = 128 * 1024; 386 unsigned long max_uncompressed = 128 * 1024; 387 int i; 388 int will_compress; 389 int compress_type = root->fs_info->compress_type; 390 int redirty = 0; 391 392 /* if this is a small write inside eof, kick off a defrag */ 393 if ((end - start + 1) < 16 * 1024 && 394 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 395 btrfs_add_inode_defrag(NULL, inode); 396 397 actual_end = min_t(u64, isize, end + 1); 398 again: 399 will_compress = 0; 400 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; 401 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); 402 403 /* 404 * we don't want to send crud past the end of i_size through 405 * compression, that's just a waste of CPU time. So, if the 406 * end of the file is before the start of our current 407 * requested range of bytes, we bail out to the uncompressed 408 * cleanup code that can deal with all of this. 409 * 410 * It isn't really the fastest way to fix things, but this is a 411 * very uncommon corner. 412 */ 413 if (actual_end <= start) 414 goto cleanup_and_bail_uncompressed; 415 416 total_compressed = actual_end - start; 417 418 /* we want to make sure that amount of ram required to uncompress 419 * an extent is reasonable, so we limit the total size in ram 420 * of a compressed extent to 128k. This is a crucial number 421 * because it also controls how easily we can spread reads across 422 * cpus for decompression. 423 * 424 * We also want to make sure the amount of IO required to do 425 * a random read is reasonably small, so we limit the size of 426 * a compressed extent to 128k. 427 */ 428 total_compressed = min(total_compressed, max_uncompressed); 429 num_bytes = ALIGN(end - start + 1, blocksize); 430 num_bytes = max(blocksize, num_bytes); 431 total_in = 0; 432 ret = 0; 433 434 /* 435 * we do compression for mount -o compress and when the 436 * inode has not been flagged as nocompress. This flag can 437 * change at any time if we discover bad compression ratios. 438 */ 439 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) && 440 (btrfs_test_opt(root, COMPRESS) || 441 (BTRFS_I(inode)->force_compress) || 442 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) { 443 WARN_ON(pages); 444 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); 445 if (!pages) { 446 /* just bail out to the uncompressed code */ 447 goto cont; 448 } 449 450 if (BTRFS_I(inode)->force_compress) 451 compress_type = BTRFS_I(inode)->force_compress; 452 453 /* 454 * we need to call clear_page_dirty_for_io on each 455 * page in the range. Otherwise applications with the file 456 * mmap'd can wander in and change the page contents while 457 * we are compressing them. 458 * 459 * If the compression fails for any reason, we set the pages 460 * dirty again later on. 461 */ 462 extent_range_clear_dirty_for_io(inode, start, end); 463 redirty = 1; 464 ret = btrfs_compress_pages(compress_type, 465 inode->i_mapping, start, 466 total_compressed, pages, 467 nr_pages, &nr_pages_ret, 468 &total_in, 469 &total_compressed, 470 max_compressed); 471 472 if (!ret) { 473 unsigned long offset = total_compressed & 474 (PAGE_CACHE_SIZE - 1); 475 struct page *page = pages[nr_pages_ret - 1]; 476 char *kaddr; 477 478 /* zero the tail end of the last page, we might be 479 * sending it down to disk 480 */ 481 if (offset) { 482 kaddr = kmap_atomic(page); 483 memset(kaddr + offset, 0, 484 PAGE_CACHE_SIZE - offset); 485 kunmap_atomic(kaddr); 486 } 487 will_compress = 1; 488 } 489 } 490 cont: 491 if (start == 0) { 492 /* lets try to make an inline extent */ 493 if (ret || total_in < (actual_end - start)) { 494 /* we didn't compress the entire range, try 495 * to make an uncompressed inline extent. 496 */ 497 ret = cow_file_range_inline(root, inode, start, end, 498 0, 0, NULL); 499 } else { 500 /* try making a compressed inline extent */ 501 ret = cow_file_range_inline(root, inode, start, end, 502 total_compressed, 503 compress_type, pages); 504 } 505 if (ret <= 0) { 506 unsigned long clear_flags = EXTENT_DELALLOC | 507 EXTENT_DEFRAG; 508 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0; 509 510 /* 511 * inline extent creation worked or returned error, 512 * we don't need to create any more async work items. 513 * Unlock and free up our temp pages. 514 */ 515 extent_clear_unlock_delalloc(inode, start, end, NULL, 516 clear_flags, PAGE_UNLOCK | 517 PAGE_CLEAR_DIRTY | 518 PAGE_SET_WRITEBACK | 519 PAGE_END_WRITEBACK); 520 goto free_pages_out; 521 } 522 } 523 524 if (will_compress) { 525 /* 526 * we aren't doing an inline extent round the compressed size 527 * up to a block size boundary so the allocator does sane 528 * things 529 */ 530 total_compressed = ALIGN(total_compressed, blocksize); 531 532 /* 533 * one last check to make sure the compression is really a 534 * win, compare the page count read with the blocks on disk 535 */ 536 total_in = ALIGN(total_in, PAGE_CACHE_SIZE); 537 if (total_compressed >= total_in) { 538 will_compress = 0; 539 } else { 540 num_bytes = total_in; 541 } 542 } 543 if (!will_compress && pages) { 544 /* 545 * the compression code ran but failed to make things smaller, 546 * free any pages it allocated and our page pointer array 547 */ 548 for (i = 0; i < nr_pages_ret; i++) { 549 WARN_ON(pages[i]->mapping); 550 page_cache_release(pages[i]); 551 } 552 kfree(pages); 553 pages = NULL; 554 total_compressed = 0; 555 nr_pages_ret = 0; 556 557 /* flag the file so we don't compress in the future */ 558 if (!btrfs_test_opt(root, FORCE_COMPRESS) && 559 !(BTRFS_I(inode)->force_compress)) { 560 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 561 } 562 } 563 if (will_compress) { 564 *num_added += 1; 565 566 /* the async work queues will take care of doing actual 567 * allocation on disk for these compressed pages, 568 * and will submit them to the elevator. 569 */ 570 add_async_extent(async_cow, start, num_bytes, 571 total_compressed, pages, nr_pages_ret, 572 compress_type); 573 574 if (start + num_bytes < end) { 575 start += num_bytes; 576 pages = NULL; 577 cond_resched(); 578 goto again; 579 } 580 } else { 581 cleanup_and_bail_uncompressed: 582 /* 583 * No compression, but we still need to write the pages in 584 * the file we've been given so far. redirty the locked 585 * page if it corresponds to our extent and set things up 586 * for the async work queue to run cow_file_range to do 587 * the normal delalloc dance 588 */ 589 if (page_offset(locked_page) >= start && 590 page_offset(locked_page) <= end) { 591 __set_page_dirty_nobuffers(locked_page); 592 /* unlocked later on in the async handlers */ 593 } 594 if (redirty) 595 extent_range_redirty_for_io(inode, start, end); 596 add_async_extent(async_cow, start, end - start + 1, 597 0, NULL, 0, BTRFS_COMPRESS_NONE); 598 *num_added += 1; 599 } 600 601 out: 602 return ret; 603 604 free_pages_out: 605 for (i = 0; i < nr_pages_ret; i++) { 606 WARN_ON(pages[i]->mapping); 607 page_cache_release(pages[i]); 608 } 609 kfree(pages); 610 611 goto out; 612 } 613 614 /* 615 * phase two of compressed writeback. This is the ordered portion 616 * of the code, which only gets called in the order the work was 617 * queued. We walk all the async extents created by compress_file_range 618 * and send them down to the disk. 619 */ 620 static noinline int submit_compressed_extents(struct inode *inode, 621 struct async_cow *async_cow) 622 { 623 struct async_extent *async_extent; 624 u64 alloc_hint = 0; 625 struct btrfs_key ins; 626 struct extent_map *em; 627 struct btrfs_root *root = BTRFS_I(inode)->root; 628 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 629 struct extent_io_tree *io_tree; 630 int ret = 0; 631 632 if (list_empty(&async_cow->extents)) 633 return 0; 634 635 again: 636 while (!list_empty(&async_cow->extents)) { 637 async_extent = list_entry(async_cow->extents.next, 638 struct async_extent, list); 639 list_del(&async_extent->list); 640 641 io_tree = &BTRFS_I(inode)->io_tree; 642 643 retry: 644 /* did the compression code fall back to uncompressed IO? */ 645 if (!async_extent->pages) { 646 int page_started = 0; 647 unsigned long nr_written = 0; 648 649 lock_extent(io_tree, async_extent->start, 650 async_extent->start + 651 async_extent->ram_size - 1); 652 653 /* allocate blocks */ 654 ret = cow_file_range(inode, async_cow->locked_page, 655 async_extent->start, 656 async_extent->start + 657 async_extent->ram_size - 1, 658 &page_started, &nr_written, 0); 659 660 /* JDM XXX */ 661 662 /* 663 * if page_started, cow_file_range inserted an 664 * inline extent and took care of all the unlocking 665 * and IO for us. Otherwise, we need to submit 666 * all those pages down to the drive. 667 */ 668 if (!page_started && !ret) 669 extent_write_locked_range(io_tree, 670 inode, async_extent->start, 671 async_extent->start + 672 async_extent->ram_size - 1, 673 btrfs_get_extent, 674 WB_SYNC_ALL); 675 else if (ret) 676 unlock_page(async_cow->locked_page); 677 kfree(async_extent); 678 cond_resched(); 679 continue; 680 } 681 682 lock_extent(io_tree, async_extent->start, 683 async_extent->start + async_extent->ram_size - 1); 684 685 ret = btrfs_reserve_extent(root, 686 async_extent->compressed_size, 687 async_extent->compressed_size, 688 0, alloc_hint, &ins, 1); 689 if (ret) { 690 int i; 691 692 for (i = 0; i < async_extent->nr_pages; i++) { 693 WARN_ON(async_extent->pages[i]->mapping); 694 page_cache_release(async_extent->pages[i]); 695 } 696 kfree(async_extent->pages); 697 async_extent->nr_pages = 0; 698 async_extent->pages = NULL; 699 700 if (ret == -ENOSPC) { 701 unlock_extent(io_tree, async_extent->start, 702 async_extent->start + 703 async_extent->ram_size - 1); 704 goto retry; 705 } 706 goto out_free; 707 } 708 709 /* 710 * here we're doing allocation and writeback of the 711 * compressed pages 712 */ 713 btrfs_drop_extent_cache(inode, async_extent->start, 714 async_extent->start + 715 async_extent->ram_size - 1, 0); 716 717 em = alloc_extent_map(); 718 if (!em) { 719 ret = -ENOMEM; 720 goto out_free_reserve; 721 } 722 em->start = async_extent->start; 723 em->len = async_extent->ram_size; 724 em->orig_start = em->start; 725 em->mod_start = em->start; 726 em->mod_len = em->len; 727 728 em->block_start = ins.objectid; 729 em->block_len = ins.offset; 730 em->orig_block_len = ins.offset; 731 em->ram_bytes = async_extent->ram_size; 732 em->bdev = root->fs_info->fs_devices->latest_bdev; 733 em->compress_type = async_extent->compress_type; 734 set_bit(EXTENT_FLAG_PINNED, &em->flags); 735 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 736 em->generation = -1; 737 738 while (1) { 739 write_lock(&em_tree->lock); 740 ret = add_extent_mapping(em_tree, em, 1); 741 write_unlock(&em_tree->lock); 742 if (ret != -EEXIST) { 743 free_extent_map(em); 744 break; 745 } 746 btrfs_drop_extent_cache(inode, async_extent->start, 747 async_extent->start + 748 async_extent->ram_size - 1, 0); 749 } 750 751 if (ret) 752 goto out_free_reserve; 753 754 ret = btrfs_add_ordered_extent_compress(inode, 755 async_extent->start, 756 ins.objectid, 757 async_extent->ram_size, 758 ins.offset, 759 BTRFS_ORDERED_COMPRESSED, 760 async_extent->compress_type); 761 if (ret) 762 goto out_free_reserve; 763 764 /* 765 * clear dirty, set writeback and unlock the pages. 766 */ 767 extent_clear_unlock_delalloc(inode, async_extent->start, 768 async_extent->start + 769 async_extent->ram_size - 1, 770 NULL, EXTENT_LOCKED | EXTENT_DELALLOC, 771 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 772 PAGE_SET_WRITEBACK); 773 ret = btrfs_submit_compressed_write(inode, 774 async_extent->start, 775 async_extent->ram_size, 776 ins.objectid, 777 ins.offset, async_extent->pages, 778 async_extent->nr_pages); 779 alloc_hint = ins.objectid + ins.offset; 780 kfree(async_extent); 781 if (ret) 782 goto out; 783 cond_resched(); 784 } 785 ret = 0; 786 out: 787 return ret; 788 out_free_reserve: 789 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 790 out_free: 791 extent_clear_unlock_delalloc(inode, async_extent->start, 792 async_extent->start + 793 async_extent->ram_size - 1, 794 NULL, EXTENT_LOCKED | EXTENT_DELALLOC | 795 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, 796 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 797 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 798 kfree(async_extent); 799 goto again; 800 } 801 802 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 803 u64 num_bytes) 804 { 805 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 806 struct extent_map *em; 807 u64 alloc_hint = 0; 808 809 read_lock(&em_tree->lock); 810 em = search_extent_mapping(em_tree, start, num_bytes); 811 if (em) { 812 /* 813 * if block start isn't an actual block number then find the 814 * first block in this inode and use that as a hint. If that 815 * block is also bogus then just don't worry about it. 816 */ 817 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 818 free_extent_map(em); 819 em = search_extent_mapping(em_tree, 0, 0); 820 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 821 alloc_hint = em->block_start; 822 if (em) 823 free_extent_map(em); 824 } else { 825 alloc_hint = em->block_start; 826 free_extent_map(em); 827 } 828 } 829 read_unlock(&em_tree->lock); 830 831 return alloc_hint; 832 } 833 834 /* 835 * when extent_io.c finds a delayed allocation range in the file, 836 * the call backs end up in this code. The basic idea is to 837 * allocate extents on disk for the range, and create ordered data structs 838 * in ram to track those extents. 839 * 840 * locked_page is the page that writepage had locked already. We use 841 * it to make sure we don't do extra locks or unlocks. 842 * 843 * *page_started is set to one if we unlock locked_page and do everything 844 * required to start IO on it. It may be clean and already done with 845 * IO when we return. 846 */ 847 static noinline int cow_file_range(struct inode *inode, 848 struct page *locked_page, 849 u64 start, u64 end, int *page_started, 850 unsigned long *nr_written, 851 int unlock) 852 { 853 struct btrfs_root *root = BTRFS_I(inode)->root; 854 u64 alloc_hint = 0; 855 u64 num_bytes; 856 unsigned long ram_size; 857 u64 disk_num_bytes; 858 u64 cur_alloc_size; 859 u64 blocksize = root->sectorsize; 860 struct btrfs_key ins; 861 struct extent_map *em; 862 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 863 int ret = 0; 864 865 if (btrfs_is_free_space_inode(inode)) { 866 WARN_ON_ONCE(1); 867 ret = -EINVAL; 868 goto out_unlock; 869 } 870 871 num_bytes = ALIGN(end - start + 1, blocksize); 872 num_bytes = max(blocksize, num_bytes); 873 disk_num_bytes = num_bytes; 874 875 /* if this is a small write inside eof, kick off defrag */ 876 if (num_bytes < 64 * 1024 && 877 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 878 btrfs_add_inode_defrag(NULL, inode); 879 880 if (start == 0) { 881 /* lets try to make an inline extent */ 882 ret = cow_file_range_inline(root, inode, start, end, 0, 0, 883 NULL); 884 if (ret == 0) { 885 extent_clear_unlock_delalloc(inode, start, end, NULL, 886 EXTENT_LOCKED | EXTENT_DELALLOC | 887 EXTENT_DEFRAG, PAGE_UNLOCK | 888 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | 889 PAGE_END_WRITEBACK); 890 891 *nr_written = *nr_written + 892 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; 893 *page_started = 1; 894 goto out; 895 } else if (ret < 0) { 896 goto out_unlock; 897 } 898 } 899 900 BUG_ON(disk_num_bytes > 901 btrfs_super_total_bytes(root->fs_info->super_copy)); 902 903 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 904 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); 905 906 while (disk_num_bytes > 0) { 907 unsigned long op; 908 909 cur_alloc_size = disk_num_bytes; 910 ret = btrfs_reserve_extent(root, cur_alloc_size, 911 root->sectorsize, 0, alloc_hint, 912 &ins, 1); 913 if (ret < 0) 914 goto out_unlock; 915 916 em = alloc_extent_map(); 917 if (!em) { 918 ret = -ENOMEM; 919 goto out_reserve; 920 } 921 em->start = start; 922 em->orig_start = em->start; 923 ram_size = ins.offset; 924 em->len = ins.offset; 925 em->mod_start = em->start; 926 em->mod_len = em->len; 927 928 em->block_start = ins.objectid; 929 em->block_len = ins.offset; 930 em->orig_block_len = ins.offset; 931 em->ram_bytes = ram_size; 932 em->bdev = root->fs_info->fs_devices->latest_bdev; 933 set_bit(EXTENT_FLAG_PINNED, &em->flags); 934 em->generation = -1; 935 936 while (1) { 937 write_lock(&em_tree->lock); 938 ret = add_extent_mapping(em_tree, em, 1); 939 write_unlock(&em_tree->lock); 940 if (ret != -EEXIST) { 941 free_extent_map(em); 942 break; 943 } 944 btrfs_drop_extent_cache(inode, start, 945 start + ram_size - 1, 0); 946 } 947 if (ret) 948 goto out_reserve; 949 950 cur_alloc_size = ins.offset; 951 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 952 ram_size, cur_alloc_size, 0); 953 if (ret) 954 goto out_reserve; 955 956 if (root->root_key.objectid == 957 BTRFS_DATA_RELOC_TREE_OBJECTID) { 958 ret = btrfs_reloc_clone_csums(inode, start, 959 cur_alloc_size); 960 if (ret) 961 goto out_reserve; 962 } 963 964 if (disk_num_bytes < cur_alloc_size) 965 break; 966 967 /* we're not doing compressed IO, don't unlock the first 968 * page (which the caller expects to stay locked), don't 969 * clear any dirty bits and don't set any writeback bits 970 * 971 * Do set the Private2 bit so we know this page was properly 972 * setup for writepage 973 */ 974 op = unlock ? PAGE_UNLOCK : 0; 975 op |= PAGE_SET_PRIVATE2; 976 977 extent_clear_unlock_delalloc(inode, start, 978 start + ram_size - 1, locked_page, 979 EXTENT_LOCKED | EXTENT_DELALLOC, 980 op); 981 disk_num_bytes -= cur_alloc_size; 982 num_bytes -= cur_alloc_size; 983 alloc_hint = ins.objectid + ins.offset; 984 start += cur_alloc_size; 985 } 986 out: 987 return ret; 988 989 out_reserve: 990 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 991 out_unlock: 992 extent_clear_unlock_delalloc(inode, start, end, locked_page, 993 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 994 EXTENT_DELALLOC | EXTENT_DEFRAG, 995 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 996 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 997 goto out; 998 } 999 1000 /* 1001 * work queue call back to started compression on a file and pages 1002 */ 1003 static noinline void async_cow_start(struct btrfs_work *work) 1004 { 1005 struct async_cow *async_cow; 1006 int num_added = 0; 1007 async_cow = container_of(work, struct async_cow, work); 1008 1009 compress_file_range(async_cow->inode, async_cow->locked_page, 1010 async_cow->start, async_cow->end, async_cow, 1011 &num_added); 1012 if (num_added == 0) { 1013 btrfs_add_delayed_iput(async_cow->inode); 1014 async_cow->inode = NULL; 1015 } 1016 } 1017 1018 /* 1019 * work queue call back to submit previously compressed pages 1020 */ 1021 static noinline void async_cow_submit(struct btrfs_work *work) 1022 { 1023 struct async_cow *async_cow; 1024 struct btrfs_root *root; 1025 unsigned long nr_pages; 1026 1027 async_cow = container_of(work, struct async_cow, work); 1028 1029 root = async_cow->root; 1030 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> 1031 PAGE_CACHE_SHIFT; 1032 1033 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 1034 5 * 1024 * 1024 && 1035 waitqueue_active(&root->fs_info->async_submit_wait)) 1036 wake_up(&root->fs_info->async_submit_wait); 1037 1038 if (async_cow->inode) 1039 submit_compressed_extents(async_cow->inode, async_cow); 1040 } 1041 1042 static noinline void async_cow_free(struct btrfs_work *work) 1043 { 1044 struct async_cow *async_cow; 1045 async_cow = container_of(work, struct async_cow, work); 1046 if (async_cow->inode) 1047 btrfs_add_delayed_iput(async_cow->inode); 1048 kfree(async_cow); 1049 } 1050 1051 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1052 u64 start, u64 end, int *page_started, 1053 unsigned long *nr_written) 1054 { 1055 struct async_cow *async_cow; 1056 struct btrfs_root *root = BTRFS_I(inode)->root; 1057 unsigned long nr_pages; 1058 u64 cur_end; 1059 int limit = 10 * 1024 * 1024; 1060 1061 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1062 1, 0, NULL, GFP_NOFS); 1063 while (start < end) { 1064 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1065 BUG_ON(!async_cow); /* -ENOMEM */ 1066 async_cow->inode = igrab(inode); 1067 async_cow->root = root; 1068 async_cow->locked_page = locked_page; 1069 async_cow->start = start; 1070 1071 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 1072 cur_end = end; 1073 else 1074 cur_end = min(end, start + 512 * 1024 - 1); 1075 1076 async_cow->end = cur_end; 1077 INIT_LIST_HEAD(&async_cow->extents); 1078 1079 btrfs_init_work(&async_cow->work, async_cow_start, 1080 async_cow_submit, async_cow_free); 1081 1082 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> 1083 PAGE_CACHE_SHIFT; 1084 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); 1085 1086 btrfs_queue_work(root->fs_info->delalloc_workers, 1087 &async_cow->work); 1088 1089 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { 1090 wait_event(root->fs_info->async_submit_wait, 1091 (atomic_read(&root->fs_info->async_delalloc_pages) < 1092 limit)); 1093 } 1094 1095 while (atomic_read(&root->fs_info->async_submit_draining) && 1096 atomic_read(&root->fs_info->async_delalloc_pages)) { 1097 wait_event(root->fs_info->async_submit_wait, 1098 (atomic_read(&root->fs_info->async_delalloc_pages) == 1099 0)); 1100 } 1101 1102 *nr_written += nr_pages; 1103 start = cur_end + 1; 1104 } 1105 *page_started = 1; 1106 return 0; 1107 } 1108 1109 static noinline int csum_exist_in_range(struct btrfs_root *root, 1110 u64 bytenr, u64 num_bytes) 1111 { 1112 int ret; 1113 struct btrfs_ordered_sum *sums; 1114 LIST_HEAD(list); 1115 1116 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, 1117 bytenr + num_bytes - 1, &list, 0); 1118 if (ret == 0 && list_empty(&list)) 1119 return 0; 1120 1121 while (!list_empty(&list)) { 1122 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1123 list_del(&sums->list); 1124 kfree(sums); 1125 } 1126 return 1; 1127 } 1128 1129 /* 1130 * when nowcow writeback call back. This checks for snapshots or COW copies 1131 * of the extents that exist in the file, and COWs the file as required. 1132 * 1133 * If no cow copies or snapshots exist, we write directly to the existing 1134 * blocks on disk 1135 */ 1136 static noinline int run_delalloc_nocow(struct inode *inode, 1137 struct page *locked_page, 1138 u64 start, u64 end, int *page_started, int force, 1139 unsigned long *nr_written) 1140 { 1141 struct btrfs_root *root = BTRFS_I(inode)->root; 1142 struct btrfs_trans_handle *trans; 1143 struct extent_buffer *leaf; 1144 struct btrfs_path *path; 1145 struct btrfs_file_extent_item *fi; 1146 struct btrfs_key found_key; 1147 u64 cow_start; 1148 u64 cur_offset; 1149 u64 extent_end; 1150 u64 extent_offset; 1151 u64 disk_bytenr; 1152 u64 num_bytes; 1153 u64 disk_num_bytes; 1154 u64 ram_bytes; 1155 int extent_type; 1156 int ret, err; 1157 int type; 1158 int nocow; 1159 int check_prev = 1; 1160 bool nolock; 1161 u64 ino = btrfs_ino(inode); 1162 1163 path = btrfs_alloc_path(); 1164 if (!path) { 1165 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1166 EXTENT_LOCKED | EXTENT_DELALLOC | 1167 EXTENT_DO_ACCOUNTING | 1168 EXTENT_DEFRAG, PAGE_UNLOCK | 1169 PAGE_CLEAR_DIRTY | 1170 PAGE_SET_WRITEBACK | 1171 PAGE_END_WRITEBACK); 1172 return -ENOMEM; 1173 } 1174 1175 nolock = btrfs_is_free_space_inode(inode); 1176 1177 if (nolock) 1178 trans = btrfs_join_transaction_nolock(root); 1179 else 1180 trans = btrfs_join_transaction(root); 1181 1182 if (IS_ERR(trans)) { 1183 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1184 EXTENT_LOCKED | EXTENT_DELALLOC | 1185 EXTENT_DO_ACCOUNTING | 1186 EXTENT_DEFRAG, PAGE_UNLOCK | 1187 PAGE_CLEAR_DIRTY | 1188 PAGE_SET_WRITEBACK | 1189 PAGE_END_WRITEBACK); 1190 btrfs_free_path(path); 1191 return PTR_ERR(trans); 1192 } 1193 1194 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1195 1196 cow_start = (u64)-1; 1197 cur_offset = start; 1198 while (1) { 1199 ret = btrfs_lookup_file_extent(trans, root, path, ino, 1200 cur_offset, 0); 1201 if (ret < 0) 1202 goto error; 1203 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1204 leaf = path->nodes[0]; 1205 btrfs_item_key_to_cpu(leaf, &found_key, 1206 path->slots[0] - 1); 1207 if (found_key.objectid == ino && 1208 found_key.type == BTRFS_EXTENT_DATA_KEY) 1209 path->slots[0]--; 1210 } 1211 check_prev = 0; 1212 next_slot: 1213 leaf = path->nodes[0]; 1214 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1215 ret = btrfs_next_leaf(root, path); 1216 if (ret < 0) 1217 goto error; 1218 if (ret > 0) 1219 break; 1220 leaf = path->nodes[0]; 1221 } 1222 1223 nocow = 0; 1224 disk_bytenr = 0; 1225 num_bytes = 0; 1226 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1227 1228 if (found_key.objectid > ino || 1229 found_key.type > BTRFS_EXTENT_DATA_KEY || 1230 found_key.offset > end) 1231 break; 1232 1233 if (found_key.offset > cur_offset) { 1234 extent_end = found_key.offset; 1235 extent_type = 0; 1236 goto out_check; 1237 } 1238 1239 fi = btrfs_item_ptr(leaf, path->slots[0], 1240 struct btrfs_file_extent_item); 1241 extent_type = btrfs_file_extent_type(leaf, fi); 1242 1243 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1244 if (extent_type == BTRFS_FILE_EXTENT_REG || 1245 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1246 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1247 extent_offset = btrfs_file_extent_offset(leaf, fi); 1248 extent_end = found_key.offset + 1249 btrfs_file_extent_num_bytes(leaf, fi); 1250 disk_num_bytes = 1251 btrfs_file_extent_disk_num_bytes(leaf, fi); 1252 if (extent_end <= start) { 1253 path->slots[0]++; 1254 goto next_slot; 1255 } 1256 if (disk_bytenr == 0) 1257 goto out_check; 1258 if (btrfs_file_extent_compression(leaf, fi) || 1259 btrfs_file_extent_encryption(leaf, fi) || 1260 btrfs_file_extent_other_encoding(leaf, fi)) 1261 goto out_check; 1262 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1263 goto out_check; 1264 if (btrfs_extent_readonly(root, disk_bytenr)) 1265 goto out_check; 1266 if (btrfs_cross_ref_exist(trans, root, ino, 1267 found_key.offset - 1268 extent_offset, disk_bytenr)) 1269 goto out_check; 1270 disk_bytenr += extent_offset; 1271 disk_bytenr += cur_offset - found_key.offset; 1272 num_bytes = min(end + 1, extent_end) - cur_offset; 1273 /* 1274 * force cow if csum exists in the range. 1275 * this ensure that csum for a given extent are 1276 * either valid or do not exist. 1277 */ 1278 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 1279 goto out_check; 1280 nocow = 1; 1281 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1282 extent_end = found_key.offset + 1283 btrfs_file_extent_inline_len(leaf, 1284 path->slots[0], fi); 1285 extent_end = ALIGN(extent_end, root->sectorsize); 1286 } else { 1287 BUG_ON(1); 1288 } 1289 out_check: 1290 if (extent_end <= start) { 1291 path->slots[0]++; 1292 goto next_slot; 1293 } 1294 if (!nocow) { 1295 if (cow_start == (u64)-1) 1296 cow_start = cur_offset; 1297 cur_offset = extent_end; 1298 if (cur_offset > end) 1299 break; 1300 path->slots[0]++; 1301 goto next_slot; 1302 } 1303 1304 btrfs_release_path(path); 1305 if (cow_start != (u64)-1) { 1306 ret = cow_file_range(inode, locked_page, 1307 cow_start, found_key.offset - 1, 1308 page_started, nr_written, 1); 1309 if (ret) 1310 goto error; 1311 cow_start = (u64)-1; 1312 } 1313 1314 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1315 struct extent_map *em; 1316 struct extent_map_tree *em_tree; 1317 em_tree = &BTRFS_I(inode)->extent_tree; 1318 em = alloc_extent_map(); 1319 BUG_ON(!em); /* -ENOMEM */ 1320 em->start = cur_offset; 1321 em->orig_start = found_key.offset - extent_offset; 1322 em->len = num_bytes; 1323 em->block_len = num_bytes; 1324 em->block_start = disk_bytenr; 1325 em->orig_block_len = disk_num_bytes; 1326 em->ram_bytes = ram_bytes; 1327 em->bdev = root->fs_info->fs_devices->latest_bdev; 1328 em->mod_start = em->start; 1329 em->mod_len = em->len; 1330 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1331 set_bit(EXTENT_FLAG_FILLING, &em->flags); 1332 em->generation = -1; 1333 while (1) { 1334 write_lock(&em_tree->lock); 1335 ret = add_extent_mapping(em_tree, em, 1); 1336 write_unlock(&em_tree->lock); 1337 if (ret != -EEXIST) { 1338 free_extent_map(em); 1339 break; 1340 } 1341 btrfs_drop_extent_cache(inode, em->start, 1342 em->start + em->len - 1, 0); 1343 } 1344 type = BTRFS_ORDERED_PREALLOC; 1345 } else { 1346 type = BTRFS_ORDERED_NOCOW; 1347 } 1348 1349 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1350 num_bytes, num_bytes, type); 1351 BUG_ON(ret); /* -ENOMEM */ 1352 1353 if (root->root_key.objectid == 1354 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1355 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1356 num_bytes); 1357 if (ret) 1358 goto error; 1359 } 1360 1361 extent_clear_unlock_delalloc(inode, cur_offset, 1362 cur_offset + num_bytes - 1, 1363 locked_page, EXTENT_LOCKED | 1364 EXTENT_DELALLOC, PAGE_UNLOCK | 1365 PAGE_SET_PRIVATE2); 1366 cur_offset = extent_end; 1367 if (cur_offset > end) 1368 break; 1369 } 1370 btrfs_release_path(path); 1371 1372 if (cur_offset <= end && cow_start == (u64)-1) { 1373 cow_start = cur_offset; 1374 cur_offset = end; 1375 } 1376 1377 if (cow_start != (u64)-1) { 1378 ret = cow_file_range(inode, locked_page, cow_start, end, 1379 page_started, nr_written, 1); 1380 if (ret) 1381 goto error; 1382 } 1383 1384 error: 1385 err = btrfs_end_transaction(trans, root); 1386 if (!ret) 1387 ret = err; 1388 1389 if (ret && cur_offset < end) 1390 extent_clear_unlock_delalloc(inode, cur_offset, end, 1391 locked_page, EXTENT_LOCKED | 1392 EXTENT_DELALLOC | EXTENT_DEFRAG | 1393 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | 1394 PAGE_CLEAR_DIRTY | 1395 PAGE_SET_WRITEBACK | 1396 PAGE_END_WRITEBACK); 1397 btrfs_free_path(path); 1398 return ret; 1399 } 1400 1401 /* 1402 * extent_io.c call back to do delayed allocation processing 1403 */ 1404 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1405 u64 start, u64 end, int *page_started, 1406 unsigned long *nr_written) 1407 { 1408 int ret; 1409 struct btrfs_root *root = BTRFS_I(inode)->root; 1410 1411 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) { 1412 ret = run_delalloc_nocow(inode, locked_page, start, end, 1413 page_started, 1, nr_written); 1414 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) { 1415 ret = run_delalloc_nocow(inode, locked_page, start, end, 1416 page_started, 0, nr_written); 1417 } else if (!btrfs_test_opt(root, COMPRESS) && 1418 !(BTRFS_I(inode)->force_compress) && 1419 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) { 1420 ret = cow_file_range(inode, locked_page, start, end, 1421 page_started, nr_written, 1); 1422 } else { 1423 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1424 &BTRFS_I(inode)->runtime_flags); 1425 ret = cow_file_range_async(inode, locked_page, start, end, 1426 page_started, nr_written); 1427 } 1428 return ret; 1429 } 1430 1431 static void btrfs_split_extent_hook(struct inode *inode, 1432 struct extent_state *orig, u64 split) 1433 { 1434 /* not delalloc, ignore it */ 1435 if (!(orig->state & EXTENT_DELALLOC)) 1436 return; 1437 1438 spin_lock(&BTRFS_I(inode)->lock); 1439 BTRFS_I(inode)->outstanding_extents++; 1440 spin_unlock(&BTRFS_I(inode)->lock); 1441 } 1442 1443 /* 1444 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1445 * extents so we can keep track of new extents that are just merged onto old 1446 * extents, such as when we are doing sequential writes, so we can properly 1447 * account for the metadata space we'll need. 1448 */ 1449 static void btrfs_merge_extent_hook(struct inode *inode, 1450 struct extent_state *new, 1451 struct extent_state *other) 1452 { 1453 /* not delalloc, ignore it */ 1454 if (!(other->state & EXTENT_DELALLOC)) 1455 return; 1456 1457 spin_lock(&BTRFS_I(inode)->lock); 1458 BTRFS_I(inode)->outstanding_extents--; 1459 spin_unlock(&BTRFS_I(inode)->lock); 1460 } 1461 1462 static void btrfs_add_delalloc_inodes(struct btrfs_root *root, 1463 struct inode *inode) 1464 { 1465 spin_lock(&root->delalloc_lock); 1466 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1467 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1468 &root->delalloc_inodes); 1469 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1470 &BTRFS_I(inode)->runtime_flags); 1471 root->nr_delalloc_inodes++; 1472 if (root->nr_delalloc_inodes == 1) { 1473 spin_lock(&root->fs_info->delalloc_root_lock); 1474 BUG_ON(!list_empty(&root->delalloc_root)); 1475 list_add_tail(&root->delalloc_root, 1476 &root->fs_info->delalloc_roots); 1477 spin_unlock(&root->fs_info->delalloc_root_lock); 1478 } 1479 } 1480 spin_unlock(&root->delalloc_lock); 1481 } 1482 1483 static void btrfs_del_delalloc_inode(struct btrfs_root *root, 1484 struct inode *inode) 1485 { 1486 spin_lock(&root->delalloc_lock); 1487 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1488 list_del_init(&BTRFS_I(inode)->delalloc_inodes); 1489 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1490 &BTRFS_I(inode)->runtime_flags); 1491 root->nr_delalloc_inodes--; 1492 if (!root->nr_delalloc_inodes) { 1493 spin_lock(&root->fs_info->delalloc_root_lock); 1494 BUG_ON(list_empty(&root->delalloc_root)); 1495 list_del_init(&root->delalloc_root); 1496 spin_unlock(&root->fs_info->delalloc_root_lock); 1497 } 1498 } 1499 spin_unlock(&root->delalloc_lock); 1500 } 1501 1502 /* 1503 * extent_io.c set_bit_hook, used to track delayed allocation 1504 * bytes in this file, and to maintain the list of inodes that 1505 * have pending delalloc work to be done. 1506 */ 1507 static void btrfs_set_bit_hook(struct inode *inode, 1508 struct extent_state *state, unsigned long *bits) 1509 { 1510 1511 /* 1512 * set_bit and clear bit hooks normally require _irqsave/restore 1513 * but in this case, we are only testing for the DELALLOC 1514 * bit, which is only set or cleared with irqs on 1515 */ 1516 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1517 struct btrfs_root *root = BTRFS_I(inode)->root; 1518 u64 len = state->end + 1 - state->start; 1519 bool do_list = !btrfs_is_free_space_inode(inode); 1520 1521 if (*bits & EXTENT_FIRST_DELALLOC) { 1522 *bits &= ~EXTENT_FIRST_DELALLOC; 1523 } else { 1524 spin_lock(&BTRFS_I(inode)->lock); 1525 BTRFS_I(inode)->outstanding_extents++; 1526 spin_unlock(&BTRFS_I(inode)->lock); 1527 } 1528 1529 __percpu_counter_add(&root->fs_info->delalloc_bytes, len, 1530 root->fs_info->delalloc_batch); 1531 spin_lock(&BTRFS_I(inode)->lock); 1532 BTRFS_I(inode)->delalloc_bytes += len; 1533 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1534 &BTRFS_I(inode)->runtime_flags)) 1535 btrfs_add_delalloc_inodes(root, inode); 1536 spin_unlock(&BTRFS_I(inode)->lock); 1537 } 1538 } 1539 1540 /* 1541 * extent_io.c clear_bit_hook, see set_bit_hook for why 1542 */ 1543 static void btrfs_clear_bit_hook(struct inode *inode, 1544 struct extent_state *state, 1545 unsigned long *bits) 1546 { 1547 /* 1548 * set_bit and clear bit hooks normally require _irqsave/restore 1549 * but in this case, we are only testing for the DELALLOC 1550 * bit, which is only set or cleared with irqs on 1551 */ 1552 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1553 struct btrfs_root *root = BTRFS_I(inode)->root; 1554 u64 len = state->end + 1 - state->start; 1555 bool do_list = !btrfs_is_free_space_inode(inode); 1556 1557 if (*bits & EXTENT_FIRST_DELALLOC) { 1558 *bits &= ~EXTENT_FIRST_DELALLOC; 1559 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1560 spin_lock(&BTRFS_I(inode)->lock); 1561 BTRFS_I(inode)->outstanding_extents--; 1562 spin_unlock(&BTRFS_I(inode)->lock); 1563 } 1564 1565 /* 1566 * We don't reserve metadata space for space cache inodes so we 1567 * don't need to call dellalloc_release_metadata if there is an 1568 * error. 1569 */ 1570 if (*bits & EXTENT_DO_ACCOUNTING && 1571 root != root->fs_info->tree_root) 1572 btrfs_delalloc_release_metadata(inode, len); 1573 1574 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1575 && do_list && !(state->state & EXTENT_NORESERVE)) 1576 btrfs_free_reserved_data_space(inode, len); 1577 1578 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, 1579 root->fs_info->delalloc_batch); 1580 spin_lock(&BTRFS_I(inode)->lock); 1581 BTRFS_I(inode)->delalloc_bytes -= len; 1582 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && 1583 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1584 &BTRFS_I(inode)->runtime_flags)) 1585 btrfs_del_delalloc_inode(root, inode); 1586 spin_unlock(&BTRFS_I(inode)->lock); 1587 } 1588 } 1589 1590 /* 1591 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1592 * we don't create bios that span stripes or chunks 1593 */ 1594 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, 1595 size_t size, struct bio *bio, 1596 unsigned long bio_flags) 1597 { 1598 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 1599 u64 logical = (u64)bio->bi_sector << 9; 1600 u64 length = 0; 1601 u64 map_length; 1602 int ret; 1603 1604 if (bio_flags & EXTENT_BIO_COMPRESSED) 1605 return 0; 1606 1607 length = bio->bi_size; 1608 map_length = length; 1609 ret = btrfs_map_block(root->fs_info, rw, logical, 1610 &map_length, NULL, 0); 1611 /* Will always return 0 with map_multi == NULL */ 1612 BUG_ON(ret < 0); 1613 if (map_length < length + size) 1614 return 1; 1615 return 0; 1616 } 1617 1618 /* 1619 * in order to insert checksums into the metadata in large chunks, 1620 * we wait until bio submission time. All the pages in the bio are 1621 * checksummed and sums are attached onto the ordered extent record. 1622 * 1623 * At IO completion time the cums attached on the ordered extent record 1624 * are inserted into the btree 1625 */ 1626 static int __btrfs_submit_bio_start(struct inode *inode, int rw, 1627 struct bio *bio, int mirror_num, 1628 unsigned long bio_flags, 1629 u64 bio_offset) 1630 { 1631 struct btrfs_root *root = BTRFS_I(inode)->root; 1632 int ret = 0; 1633 1634 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1635 BUG_ON(ret); /* -ENOMEM */ 1636 return 0; 1637 } 1638 1639 /* 1640 * in order to insert checksums into the metadata in large chunks, 1641 * we wait until bio submission time. All the pages in the bio are 1642 * checksummed and sums are attached onto the ordered extent record. 1643 * 1644 * At IO completion time the cums attached on the ordered extent record 1645 * are inserted into the btree 1646 */ 1647 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 1648 int mirror_num, unsigned long bio_flags, 1649 u64 bio_offset) 1650 { 1651 struct btrfs_root *root = BTRFS_I(inode)->root; 1652 int ret; 1653 1654 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); 1655 if (ret) 1656 bio_endio(bio, ret); 1657 return ret; 1658 } 1659 1660 /* 1661 * extent_io.c submission hook. This does the right thing for csum calculation 1662 * on write, or reading the csums from the tree before a read 1663 */ 1664 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 1665 int mirror_num, unsigned long bio_flags, 1666 u64 bio_offset) 1667 { 1668 struct btrfs_root *root = BTRFS_I(inode)->root; 1669 int ret = 0; 1670 int skip_sum; 1671 int metadata = 0; 1672 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1673 1674 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1675 1676 if (btrfs_is_free_space_inode(inode)) 1677 metadata = 2; 1678 1679 if (!(rw & REQ_WRITE)) { 1680 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); 1681 if (ret) 1682 goto out; 1683 1684 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1685 ret = btrfs_submit_compressed_read(inode, bio, 1686 mirror_num, 1687 bio_flags); 1688 goto out; 1689 } else if (!skip_sum) { 1690 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); 1691 if (ret) 1692 goto out; 1693 } 1694 goto mapit; 1695 } else if (async && !skip_sum) { 1696 /* csum items have already been cloned */ 1697 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1698 goto mapit; 1699 /* we're doing a write, do the async checksumming */ 1700 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 1701 inode, rw, bio, mirror_num, 1702 bio_flags, bio_offset, 1703 __btrfs_submit_bio_start, 1704 __btrfs_submit_bio_done); 1705 goto out; 1706 } else if (!skip_sum) { 1707 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1708 if (ret) 1709 goto out; 1710 } 1711 1712 mapit: 1713 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 1714 1715 out: 1716 if (ret < 0) 1717 bio_endio(bio, ret); 1718 return ret; 1719 } 1720 1721 /* 1722 * given a list of ordered sums record them in the inode. This happens 1723 * at IO completion time based on sums calculated at bio submission time. 1724 */ 1725 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1726 struct inode *inode, u64 file_offset, 1727 struct list_head *list) 1728 { 1729 struct btrfs_ordered_sum *sum; 1730 1731 list_for_each_entry(sum, list, list) { 1732 trans->adding_csums = 1; 1733 btrfs_csum_file_blocks(trans, 1734 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1735 trans->adding_csums = 0; 1736 } 1737 return 0; 1738 } 1739 1740 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1741 struct extent_state **cached_state) 1742 { 1743 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); 1744 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1745 cached_state, GFP_NOFS); 1746 } 1747 1748 /* see btrfs_writepage_start_hook for details on why this is required */ 1749 struct btrfs_writepage_fixup { 1750 struct page *page; 1751 struct btrfs_work work; 1752 }; 1753 1754 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1755 { 1756 struct btrfs_writepage_fixup *fixup; 1757 struct btrfs_ordered_extent *ordered; 1758 struct extent_state *cached_state = NULL; 1759 struct page *page; 1760 struct inode *inode; 1761 u64 page_start; 1762 u64 page_end; 1763 int ret; 1764 1765 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1766 page = fixup->page; 1767 again: 1768 lock_page(page); 1769 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1770 ClearPageChecked(page); 1771 goto out_page; 1772 } 1773 1774 inode = page->mapping->host; 1775 page_start = page_offset(page); 1776 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; 1777 1778 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, 1779 &cached_state); 1780 1781 /* already ordered? We're done */ 1782 if (PagePrivate2(page)) 1783 goto out; 1784 1785 ordered = btrfs_lookup_ordered_extent(inode, page_start); 1786 if (ordered) { 1787 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 1788 page_end, &cached_state, GFP_NOFS); 1789 unlock_page(page); 1790 btrfs_start_ordered_extent(inode, ordered, 1); 1791 btrfs_put_ordered_extent(ordered); 1792 goto again; 1793 } 1794 1795 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 1796 if (ret) { 1797 mapping_set_error(page->mapping, ret); 1798 end_extent_writepage(page, ret, page_start, page_end); 1799 ClearPageChecked(page); 1800 goto out; 1801 } 1802 1803 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); 1804 ClearPageChecked(page); 1805 set_page_dirty(page); 1806 out: 1807 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 1808 &cached_state, GFP_NOFS); 1809 out_page: 1810 unlock_page(page); 1811 page_cache_release(page); 1812 kfree(fixup); 1813 } 1814 1815 /* 1816 * There are a few paths in the higher layers of the kernel that directly 1817 * set the page dirty bit without asking the filesystem if it is a 1818 * good idea. This causes problems because we want to make sure COW 1819 * properly happens and the data=ordered rules are followed. 1820 * 1821 * In our case any range that doesn't have the ORDERED bit set 1822 * hasn't been properly setup for IO. We kick off an async process 1823 * to fix it up. The async helper will wait for ordered extents, set 1824 * the delalloc bit and make it safe to write the page. 1825 */ 1826 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 1827 { 1828 struct inode *inode = page->mapping->host; 1829 struct btrfs_writepage_fixup *fixup; 1830 struct btrfs_root *root = BTRFS_I(inode)->root; 1831 1832 /* this page is properly in the ordered list */ 1833 if (TestClearPagePrivate2(page)) 1834 return 0; 1835 1836 if (PageChecked(page)) 1837 return -EAGAIN; 1838 1839 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 1840 if (!fixup) 1841 return -EAGAIN; 1842 1843 SetPageChecked(page); 1844 page_cache_get(page); 1845 btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL); 1846 fixup->page = page; 1847 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work); 1848 return -EBUSY; 1849 } 1850 1851 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 1852 struct inode *inode, u64 file_pos, 1853 u64 disk_bytenr, u64 disk_num_bytes, 1854 u64 num_bytes, u64 ram_bytes, 1855 u8 compression, u8 encryption, 1856 u16 other_encoding, int extent_type) 1857 { 1858 struct btrfs_root *root = BTRFS_I(inode)->root; 1859 struct btrfs_file_extent_item *fi; 1860 struct btrfs_path *path; 1861 struct extent_buffer *leaf; 1862 struct btrfs_key ins; 1863 int extent_inserted = 0; 1864 int ret; 1865 1866 path = btrfs_alloc_path(); 1867 if (!path) 1868 return -ENOMEM; 1869 1870 /* 1871 * we may be replacing one extent in the tree with another. 1872 * The new extent is pinned in the extent map, and we don't want 1873 * to drop it from the cache until it is completely in the btree. 1874 * 1875 * So, tell btrfs_drop_extents to leave this extent in the cache. 1876 * the caller is expected to unpin it and allow it to be merged 1877 * with the others. 1878 */ 1879 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, 1880 file_pos + num_bytes, NULL, 0, 1881 1, sizeof(*fi), &extent_inserted); 1882 if (ret) 1883 goto out; 1884 1885 if (!extent_inserted) { 1886 ins.objectid = btrfs_ino(inode); 1887 ins.offset = file_pos; 1888 ins.type = BTRFS_EXTENT_DATA_KEY; 1889 1890 path->leave_spinning = 1; 1891 ret = btrfs_insert_empty_item(trans, root, path, &ins, 1892 sizeof(*fi)); 1893 if (ret) 1894 goto out; 1895 } 1896 leaf = path->nodes[0]; 1897 fi = btrfs_item_ptr(leaf, path->slots[0], 1898 struct btrfs_file_extent_item); 1899 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1900 btrfs_set_file_extent_type(leaf, fi, extent_type); 1901 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 1902 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 1903 btrfs_set_file_extent_offset(leaf, fi, 0); 1904 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 1905 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 1906 btrfs_set_file_extent_compression(leaf, fi, compression); 1907 btrfs_set_file_extent_encryption(leaf, fi, encryption); 1908 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 1909 1910 btrfs_mark_buffer_dirty(leaf); 1911 btrfs_release_path(path); 1912 1913 inode_add_bytes(inode, num_bytes); 1914 1915 ins.objectid = disk_bytenr; 1916 ins.offset = disk_num_bytes; 1917 ins.type = BTRFS_EXTENT_ITEM_KEY; 1918 ret = btrfs_alloc_reserved_file_extent(trans, root, 1919 root->root_key.objectid, 1920 btrfs_ino(inode), file_pos, &ins); 1921 out: 1922 btrfs_free_path(path); 1923 1924 return ret; 1925 } 1926 1927 /* snapshot-aware defrag */ 1928 struct sa_defrag_extent_backref { 1929 struct rb_node node; 1930 struct old_sa_defrag_extent *old; 1931 u64 root_id; 1932 u64 inum; 1933 u64 file_pos; 1934 u64 extent_offset; 1935 u64 num_bytes; 1936 u64 generation; 1937 }; 1938 1939 struct old_sa_defrag_extent { 1940 struct list_head list; 1941 struct new_sa_defrag_extent *new; 1942 1943 u64 extent_offset; 1944 u64 bytenr; 1945 u64 offset; 1946 u64 len; 1947 int count; 1948 }; 1949 1950 struct new_sa_defrag_extent { 1951 struct rb_root root; 1952 struct list_head head; 1953 struct btrfs_path *path; 1954 struct inode *inode; 1955 u64 file_pos; 1956 u64 len; 1957 u64 bytenr; 1958 u64 disk_len; 1959 u8 compress_type; 1960 }; 1961 1962 static int backref_comp(struct sa_defrag_extent_backref *b1, 1963 struct sa_defrag_extent_backref *b2) 1964 { 1965 if (b1->root_id < b2->root_id) 1966 return -1; 1967 else if (b1->root_id > b2->root_id) 1968 return 1; 1969 1970 if (b1->inum < b2->inum) 1971 return -1; 1972 else if (b1->inum > b2->inum) 1973 return 1; 1974 1975 if (b1->file_pos < b2->file_pos) 1976 return -1; 1977 else if (b1->file_pos > b2->file_pos) 1978 return 1; 1979 1980 /* 1981 * [------------------------------] ===> (a range of space) 1982 * |<--->| |<---->| =============> (fs/file tree A) 1983 * |<---------------------------->| ===> (fs/file tree B) 1984 * 1985 * A range of space can refer to two file extents in one tree while 1986 * refer to only one file extent in another tree. 1987 * 1988 * So we may process a disk offset more than one time(two extents in A) 1989 * and locate at the same extent(one extent in B), then insert two same 1990 * backrefs(both refer to the extent in B). 1991 */ 1992 return 0; 1993 } 1994 1995 static void backref_insert(struct rb_root *root, 1996 struct sa_defrag_extent_backref *backref) 1997 { 1998 struct rb_node **p = &root->rb_node; 1999 struct rb_node *parent = NULL; 2000 struct sa_defrag_extent_backref *entry; 2001 int ret; 2002 2003 while (*p) { 2004 parent = *p; 2005 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2006 2007 ret = backref_comp(backref, entry); 2008 if (ret < 0) 2009 p = &(*p)->rb_left; 2010 else 2011 p = &(*p)->rb_right; 2012 } 2013 2014 rb_link_node(&backref->node, parent, p); 2015 rb_insert_color(&backref->node, root); 2016 } 2017 2018 /* 2019 * Note the backref might has changed, and in this case we just return 0. 2020 */ 2021 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2022 void *ctx) 2023 { 2024 struct btrfs_file_extent_item *extent; 2025 struct btrfs_fs_info *fs_info; 2026 struct old_sa_defrag_extent *old = ctx; 2027 struct new_sa_defrag_extent *new = old->new; 2028 struct btrfs_path *path = new->path; 2029 struct btrfs_key key; 2030 struct btrfs_root *root; 2031 struct sa_defrag_extent_backref *backref; 2032 struct extent_buffer *leaf; 2033 struct inode *inode = new->inode; 2034 int slot; 2035 int ret; 2036 u64 extent_offset; 2037 u64 num_bytes; 2038 2039 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2040 inum == btrfs_ino(inode)) 2041 return 0; 2042 2043 key.objectid = root_id; 2044 key.type = BTRFS_ROOT_ITEM_KEY; 2045 key.offset = (u64)-1; 2046 2047 fs_info = BTRFS_I(inode)->root->fs_info; 2048 root = btrfs_read_fs_root_no_name(fs_info, &key); 2049 if (IS_ERR(root)) { 2050 if (PTR_ERR(root) == -ENOENT) 2051 return 0; 2052 WARN_ON(1); 2053 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", 2054 inum, offset, root_id); 2055 return PTR_ERR(root); 2056 } 2057 2058 key.objectid = inum; 2059 key.type = BTRFS_EXTENT_DATA_KEY; 2060 if (offset > (u64)-1 << 32) 2061 key.offset = 0; 2062 else 2063 key.offset = offset; 2064 2065 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2066 if (WARN_ON(ret < 0)) 2067 return ret; 2068 ret = 0; 2069 2070 while (1) { 2071 cond_resched(); 2072 2073 leaf = path->nodes[0]; 2074 slot = path->slots[0]; 2075 2076 if (slot >= btrfs_header_nritems(leaf)) { 2077 ret = btrfs_next_leaf(root, path); 2078 if (ret < 0) { 2079 goto out; 2080 } else if (ret > 0) { 2081 ret = 0; 2082 goto out; 2083 } 2084 continue; 2085 } 2086 2087 path->slots[0]++; 2088 2089 btrfs_item_key_to_cpu(leaf, &key, slot); 2090 2091 if (key.objectid > inum) 2092 goto out; 2093 2094 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2095 continue; 2096 2097 extent = btrfs_item_ptr(leaf, slot, 2098 struct btrfs_file_extent_item); 2099 2100 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2101 continue; 2102 2103 /* 2104 * 'offset' refers to the exact key.offset, 2105 * NOT the 'offset' field in btrfs_extent_data_ref, ie. 2106 * (key.offset - extent_offset). 2107 */ 2108 if (key.offset != offset) 2109 continue; 2110 2111 extent_offset = btrfs_file_extent_offset(leaf, extent); 2112 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2113 2114 if (extent_offset >= old->extent_offset + old->offset + 2115 old->len || extent_offset + num_bytes <= 2116 old->extent_offset + old->offset) 2117 continue; 2118 break; 2119 } 2120 2121 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2122 if (!backref) { 2123 ret = -ENOENT; 2124 goto out; 2125 } 2126 2127 backref->root_id = root_id; 2128 backref->inum = inum; 2129 backref->file_pos = offset; 2130 backref->num_bytes = num_bytes; 2131 backref->extent_offset = extent_offset; 2132 backref->generation = btrfs_file_extent_generation(leaf, extent); 2133 backref->old = old; 2134 backref_insert(&new->root, backref); 2135 old->count++; 2136 out: 2137 btrfs_release_path(path); 2138 WARN_ON(ret); 2139 return ret; 2140 } 2141 2142 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2143 struct new_sa_defrag_extent *new) 2144 { 2145 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; 2146 struct old_sa_defrag_extent *old, *tmp; 2147 int ret; 2148 2149 new->path = path; 2150 2151 list_for_each_entry_safe(old, tmp, &new->head, list) { 2152 ret = iterate_inodes_from_logical(old->bytenr + 2153 old->extent_offset, fs_info, 2154 path, record_one_backref, 2155 old); 2156 if (ret < 0 && ret != -ENOENT) 2157 return false; 2158 2159 /* no backref to be processed for this extent */ 2160 if (!old->count) { 2161 list_del(&old->list); 2162 kfree(old); 2163 } 2164 } 2165 2166 if (list_empty(&new->head)) 2167 return false; 2168 2169 return true; 2170 } 2171 2172 static int relink_is_mergable(struct extent_buffer *leaf, 2173 struct btrfs_file_extent_item *fi, 2174 struct new_sa_defrag_extent *new) 2175 { 2176 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) 2177 return 0; 2178 2179 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2180 return 0; 2181 2182 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) 2183 return 0; 2184 2185 if (btrfs_file_extent_encryption(leaf, fi) || 2186 btrfs_file_extent_other_encoding(leaf, fi)) 2187 return 0; 2188 2189 return 1; 2190 } 2191 2192 /* 2193 * Note the backref might has changed, and in this case we just return 0. 2194 */ 2195 static noinline int relink_extent_backref(struct btrfs_path *path, 2196 struct sa_defrag_extent_backref *prev, 2197 struct sa_defrag_extent_backref *backref) 2198 { 2199 struct btrfs_file_extent_item *extent; 2200 struct btrfs_file_extent_item *item; 2201 struct btrfs_ordered_extent *ordered; 2202 struct btrfs_trans_handle *trans; 2203 struct btrfs_fs_info *fs_info; 2204 struct btrfs_root *root; 2205 struct btrfs_key key; 2206 struct extent_buffer *leaf; 2207 struct old_sa_defrag_extent *old = backref->old; 2208 struct new_sa_defrag_extent *new = old->new; 2209 struct inode *src_inode = new->inode; 2210 struct inode *inode; 2211 struct extent_state *cached = NULL; 2212 int ret = 0; 2213 u64 start; 2214 u64 len; 2215 u64 lock_start; 2216 u64 lock_end; 2217 bool merge = false; 2218 int index; 2219 2220 if (prev && prev->root_id == backref->root_id && 2221 prev->inum == backref->inum && 2222 prev->file_pos + prev->num_bytes == backref->file_pos) 2223 merge = true; 2224 2225 /* step 1: get root */ 2226 key.objectid = backref->root_id; 2227 key.type = BTRFS_ROOT_ITEM_KEY; 2228 key.offset = (u64)-1; 2229 2230 fs_info = BTRFS_I(src_inode)->root->fs_info; 2231 index = srcu_read_lock(&fs_info->subvol_srcu); 2232 2233 root = btrfs_read_fs_root_no_name(fs_info, &key); 2234 if (IS_ERR(root)) { 2235 srcu_read_unlock(&fs_info->subvol_srcu, index); 2236 if (PTR_ERR(root) == -ENOENT) 2237 return 0; 2238 return PTR_ERR(root); 2239 } 2240 2241 if (btrfs_root_readonly(root)) { 2242 srcu_read_unlock(&fs_info->subvol_srcu, index); 2243 return 0; 2244 } 2245 2246 /* step 2: get inode */ 2247 key.objectid = backref->inum; 2248 key.type = BTRFS_INODE_ITEM_KEY; 2249 key.offset = 0; 2250 2251 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2252 if (IS_ERR(inode)) { 2253 srcu_read_unlock(&fs_info->subvol_srcu, index); 2254 return 0; 2255 } 2256 2257 srcu_read_unlock(&fs_info->subvol_srcu, index); 2258 2259 /* step 3: relink backref */ 2260 lock_start = backref->file_pos; 2261 lock_end = backref->file_pos + backref->num_bytes - 1; 2262 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2263 0, &cached); 2264 2265 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2266 if (ordered) { 2267 btrfs_put_ordered_extent(ordered); 2268 goto out_unlock; 2269 } 2270 2271 trans = btrfs_join_transaction(root); 2272 if (IS_ERR(trans)) { 2273 ret = PTR_ERR(trans); 2274 goto out_unlock; 2275 } 2276 2277 key.objectid = backref->inum; 2278 key.type = BTRFS_EXTENT_DATA_KEY; 2279 key.offset = backref->file_pos; 2280 2281 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2282 if (ret < 0) { 2283 goto out_free_path; 2284 } else if (ret > 0) { 2285 ret = 0; 2286 goto out_free_path; 2287 } 2288 2289 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2290 struct btrfs_file_extent_item); 2291 2292 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2293 backref->generation) 2294 goto out_free_path; 2295 2296 btrfs_release_path(path); 2297 2298 start = backref->file_pos; 2299 if (backref->extent_offset < old->extent_offset + old->offset) 2300 start += old->extent_offset + old->offset - 2301 backref->extent_offset; 2302 2303 len = min(backref->extent_offset + backref->num_bytes, 2304 old->extent_offset + old->offset + old->len); 2305 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2306 2307 ret = btrfs_drop_extents(trans, root, inode, start, 2308 start + len, 1); 2309 if (ret) 2310 goto out_free_path; 2311 again: 2312 key.objectid = btrfs_ino(inode); 2313 key.type = BTRFS_EXTENT_DATA_KEY; 2314 key.offset = start; 2315 2316 path->leave_spinning = 1; 2317 if (merge) { 2318 struct btrfs_file_extent_item *fi; 2319 u64 extent_len; 2320 struct btrfs_key found_key; 2321 2322 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 2323 if (ret < 0) 2324 goto out_free_path; 2325 2326 path->slots[0]--; 2327 leaf = path->nodes[0]; 2328 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2329 2330 fi = btrfs_item_ptr(leaf, path->slots[0], 2331 struct btrfs_file_extent_item); 2332 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2333 2334 if (extent_len + found_key.offset == start && 2335 relink_is_mergable(leaf, fi, new)) { 2336 btrfs_set_file_extent_num_bytes(leaf, fi, 2337 extent_len + len); 2338 btrfs_mark_buffer_dirty(leaf); 2339 inode_add_bytes(inode, len); 2340 2341 ret = 1; 2342 goto out_free_path; 2343 } else { 2344 merge = false; 2345 btrfs_release_path(path); 2346 goto again; 2347 } 2348 } 2349 2350 ret = btrfs_insert_empty_item(trans, root, path, &key, 2351 sizeof(*extent)); 2352 if (ret) { 2353 btrfs_abort_transaction(trans, root, ret); 2354 goto out_free_path; 2355 } 2356 2357 leaf = path->nodes[0]; 2358 item = btrfs_item_ptr(leaf, path->slots[0], 2359 struct btrfs_file_extent_item); 2360 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2361 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2362 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2363 btrfs_set_file_extent_num_bytes(leaf, item, len); 2364 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2365 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2366 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2367 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2368 btrfs_set_file_extent_encryption(leaf, item, 0); 2369 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2370 2371 btrfs_mark_buffer_dirty(leaf); 2372 inode_add_bytes(inode, len); 2373 btrfs_release_path(path); 2374 2375 ret = btrfs_inc_extent_ref(trans, root, new->bytenr, 2376 new->disk_len, 0, 2377 backref->root_id, backref->inum, 2378 new->file_pos, 0); /* start - extent_offset */ 2379 if (ret) { 2380 btrfs_abort_transaction(trans, root, ret); 2381 goto out_free_path; 2382 } 2383 2384 ret = 1; 2385 out_free_path: 2386 btrfs_release_path(path); 2387 path->leave_spinning = 0; 2388 btrfs_end_transaction(trans, root); 2389 out_unlock: 2390 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2391 &cached, GFP_NOFS); 2392 iput(inode); 2393 return ret; 2394 } 2395 2396 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) 2397 { 2398 struct old_sa_defrag_extent *old, *tmp; 2399 2400 if (!new) 2401 return; 2402 2403 list_for_each_entry_safe(old, tmp, &new->head, list) { 2404 list_del(&old->list); 2405 kfree(old); 2406 } 2407 kfree(new); 2408 } 2409 2410 static void relink_file_extents(struct new_sa_defrag_extent *new) 2411 { 2412 struct btrfs_path *path; 2413 struct sa_defrag_extent_backref *backref; 2414 struct sa_defrag_extent_backref *prev = NULL; 2415 struct inode *inode; 2416 struct btrfs_root *root; 2417 struct rb_node *node; 2418 int ret; 2419 2420 inode = new->inode; 2421 root = BTRFS_I(inode)->root; 2422 2423 path = btrfs_alloc_path(); 2424 if (!path) 2425 return; 2426 2427 if (!record_extent_backrefs(path, new)) { 2428 btrfs_free_path(path); 2429 goto out; 2430 } 2431 btrfs_release_path(path); 2432 2433 while (1) { 2434 node = rb_first(&new->root); 2435 if (!node) 2436 break; 2437 rb_erase(node, &new->root); 2438 2439 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2440 2441 ret = relink_extent_backref(path, prev, backref); 2442 WARN_ON(ret < 0); 2443 2444 kfree(prev); 2445 2446 if (ret == 1) 2447 prev = backref; 2448 else 2449 prev = NULL; 2450 cond_resched(); 2451 } 2452 kfree(prev); 2453 2454 btrfs_free_path(path); 2455 out: 2456 free_sa_defrag_extent(new); 2457 2458 atomic_dec(&root->fs_info->defrag_running); 2459 wake_up(&root->fs_info->transaction_wait); 2460 } 2461 2462 static struct new_sa_defrag_extent * 2463 record_old_file_extents(struct inode *inode, 2464 struct btrfs_ordered_extent *ordered) 2465 { 2466 struct btrfs_root *root = BTRFS_I(inode)->root; 2467 struct btrfs_path *path; 2468 struct btrfs_key key; 2469 struct old_sa_defrag_extent *old; 2470 struct new_sa_defrag_extent *new; 2471 int ret; 2472 2473 new = kmalloc(sizeof(*new), GFP_NOFS); 2474 if (!new) 2475 return NULL; 2476 2477 new->inode = inode; 2478 new->file_pos = ordered->file_offset; 2479 new->len = ordered->len; 2480 new->bytenr = ordered->start; 2481 new->disk_len = ordered->disk_len; 2482 new->compress_type = ordered->compress_type; 2483 new->root = RB_ROOT; 2484 INIT_LIST_HEAD(&new->head); 2485 2486 path = btrfs_alloc_path(); 2487 if (!path) 2488 goto out_kfree; 2489 2490 key.objectid = btrfs_ino(inode); 2491 key.type = BTRFS_EXTENT_DATA_KEY; 2492 key.offset = new->file_pos; 2493 2494 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2495 if (ret < 0) 2496 goto out_free_path; 2497 if (ret > 0 && path->slots[0] > 0) 2498 path->slots[0]--; 2499 2500 /* find out all the old extents for the file range */ 2501 while (1) { 2502 struct btrfs_file_extent_item *extent; 2503 struct extent_buffer *l; 2504 int slot; 2505 u64 num_bytes; 2506 u64 offset; 2507 u64 end; 2508 u64 disk_bytenr; 2509 u64 extent_offset; 2510 2511 l = path->nodes[0]; 2512 slot = path->slots[0]; 2513 2514 if (slot >= btrfs_header_nritems(l)) { 2515 ret = btrfs_next_leaf(root, path); 2516 if (ret < 0) 2517 goto out_free_path; 2518 else if (ret > 0) 2519 break; 2520 continue; 2521 } 2522 2523 btrfs_item_key_to_cpu(l, &key, slot); 2524 2525 if (key.objectid != btrfs_ino(inode)) 2526 break; 2527 if (key.type != BTRFS_EXTENT_DATA_KEY) 2528 break; 2529 if (key.offset >= new->file_pos + new->len) 2530 break; 2531 2532 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2533 2534 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2535 if (key.offset + num_bytes < new->file_pos) 2536 goto next; 2537 2538 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2539 if (!disk_bytenr) 2540 goto next; 2541 2542 extent_offset = btrfs_file_extent_offset(l, extent); 2543 2544 old = kmalloc(sizeof(*old), GFP_NOFS); 2545 if (!old) 2546 goto out_free_path; 2547 2548 offset = max(new->file_pos, key.offset); 2549 end = min(new->file_pos + new->len, key.offset + num_bytes); 2550 2551 old->bytenr = disk_bytenr; 2552 old->extent_offset = extent_offset; 2553 old->offset = offset - key.offset; 2554 old->len = end - offset; 2555 old->new = new; 2556 old->count = 0; 2557 list_add_tail(&old->list, &new->head); 2558 next: 2559 path->slots[0]++; 2560 cond_resched(); 2561 } 2562 2563 btrfs_free_path(path); 2564 atomic_inc(&root->fs_info->defrag_running); 2565 2566 return new; 2567 2568 out_free_path: 2569 btrfs_free_path(path); 2570 out_kfree: 2571 free_sa_defrag_extent(new); 2572 return NULL; 2573 } 2574 2575 /* as ordered data IO finishes, this gets called so we can finish 2576 * an ordered extent if the range of bytes in the file it covers are 2577 * fully written. 2578 */ 2579 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2580 { 2581 struct inode *inode = ordered_extent->inode; 2582 struct btrfs_root *root = BTRFS_I(inode)->root; 2583 struct btrfs_trans_handle *trans = NULL; 2584 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2585 struct extent_state *cached_state = NULL; 2586 struct new_sa_defrag_extent *new = NULL; 2587 int compress_type = 0; 2588 int ret = 0; 2589 u64 logical_len = ordered_extent->len; 2590 bool nolock; 2591 bool truncated = false; 2592 2593 nolock = btrfs_is_free_space_inode(inode); 2594 2595 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2596 ret = -EIO; 2597 goto out; 2598 } 2599 2600 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { 2601 truncated = true; 2602 logical_len = ordered_extent->truncated_len; 2603 /* Truncated the entire extent, don't bother adding */ 2604 if (!logical_len) 2605 goto out; 2606 } 2607 2608 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2609 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2610 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2611 if (nolock) 2612 trans = btrfs_join_transaction_nolock(root); 2613 else 2614 trans = btrfs_join_transaction(root); 2615 if (IS_ERR(trans)) { 2616 ret = PTR_ERR(trans); 2617 trans = NULL; 2618 goto out; 2619 } 2620 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2621 ret = btrfs_update_inode_fallback(trans, root, inode); 2622 if (ret) /* -ENOMEM or corruption */ 2623 btrfs_abort_transaction(trans, root, ret); 2624 goto out; 2625 } 2626 2627 lock_extent_bits(io_tree, ordered_extent->file_offset, 2628 ordered_extent->file_offset + ordered_extent->len - 1, 2629 0, &cached_state); 2630 2631 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2632 ordered_extent->file_offset + ordered_extent->len - 1, 2633 EXTENT_DEFRAG, 1, cached_state); 2634 if (ret) { 2635 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2636 if (0 && last_snapshot >= BTRFS_I(inode)->generation) 2637 /* the inode is shared */ 2638 new = record_old_file_extents(inode, ordered_extent); 2639 2640 clear_extent_bit(io_tree, ordered_extent->file_offset, 2641 ordered_extent->file_offset + ordered_extent->len - 1, 2642 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2643 } 2644 2645 if (nolock) 2646 trans = btrfs_join_transaction_nolock(root); 2647 else 2648 trans = btrfs_join_transaction(root); 2649 if (IS_ERR(trans)) { 2650 ret = PTR_ERR(trans); 2651 trans = NULL; 2652 goto out_unlock; 2653 } 2654 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2655 2656 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2657 compress_type = ordered_extent->compress_type; 2658 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2659 BUG_ON(compress_type); 2660 ret = btrfs_mark_extent_written(trans, inode, 2661 ordered_extent->file_offset, 2662 ordered_extent->file_offset + 2663 logical_len); 2664 } else { 2665 BUG_ON(root == root->fs_info->tree_root); 2666 ret = insert_reserved_file_extent(trans, inode, 2667 ordered_extent->file_offset, 2668 ordered_extent->start, 2669 ordered_extent->disk_len, 2670 logical_len, logical_len, 2671 compress_type, 0, 0, 2672 BTRFS_FILE_EXTENT_REG); 2673 } 2674 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2675 ordered_extent->file_offset, ordered_extent->len, 2676 trans->transid); 2677 if (ret < 0) { 2678 btrfs_abort_transaction(trans, root, ret); 2679 goto out_unlock; 2680 } 2681 2682 add_pending_csums(trans, inode, ordered_extent->file_offset, 2683 &ordered_extent->list); 2684 2685 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2686 ret = btrfs_update_inode_fallback(trans, root, inode); 2687 if (ret) { /* -ENOMEM or corruption */ 2688 btrfs_abort_transaction(trans, root, ret); 2689 goto out_unlock; 2690 } 2691 ret = 0; 2692 out_unlock: 2693 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2694 ordered_extent->file_offset + 2695 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2696 out: 2697 if (root != root->fs_info->tree_root) 2698 btrfs_delalloc_release_metadata(inode, ordered_extent->len); 2699 if (trans) 2700 btrfs_end_transaction(trans, root); 2701 2702 if (ret || truncated) { 2703 u64 start, end; 2704 2705 if (truncated) 2706 start = ordered_extent->file_offset + logical_len; 2707 else 2708 start = ordered_extent->file_offset; 2709 end = ordered_extent->file_offset + ordered_extent->len - 1; 2710 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); 2711 2712 /* Drop the cache for the part of the extent we didn't write. */ 2713 btrfs_drop_extent_cache(inode, start, end, 0); 2714 2715 /* 2716 * If the ordered extent had an IOERR or something else went 2717 * wrong we need to return the space for this ordered extent 2718 * back to the allocator. We only free the extent in the 2719 * truncated case if we didn't write out the extent at all. 2720 */ 2721 if ((ret || !logical_len) && 2722 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2723 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2724 btrfs_free_reserved_extent(root, ordered_extent->start, 2725 ordered_extent->disk_len); 2726 } 2727 2728 2729 /* 2730 * This needs to be done to make sure anybody waiting knows we are done 2731 * updating everything for this ordered extent. 2732 */ 2733 btrfs_remove_ordered_extent(inode, ordered_extent); 2734 2735 /* for snapshot-aware defrag */ 2736 if (new) { 2737 if (ret) { 2738 free_sa_defrag_extent(new); 2739 atomic_dec(&root->fs_info->defrag_running); 2740 } else { 2741 relink_file_extents(new); 2742 } 2743 } 2744 2745 /* once for us */ 2746 btrfs_put_ordered_extent(ordered_extent); 2747 /* once for the tree */ 2748 btrfs_put_ordered_extent(ordered_extent); 2749 2750 return ret; 2751 } 2752 2753 static void finish_ordered_fn(struct btrfs_work *work) 2754 { 2755 struct btrfs_ordered_extent *ordered_extent; 2756 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 2757 btrfs_finish_ordered_io(ordered_extent); 2758 } 2759 2760 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 2761 struct extent_state *state, int uptodate) 2762 { 2763 struct inode *inode = page->mapping->host; 2764 struct btrfs_root *root = BTRFS_I(inode)->root; 2765 struct btrfs_ordered_extent *ordered_extent = NULL; 2766 struct btrfs_workqueue *workers; 2767 2768 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 2769 2770 ClearPagePrivate2(page); 2771 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 2772 end - start + 1, uptodate)) 2773 return 0; 2774 2775 btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL); 2776 2777 if (btrfs_is_free_space_inode(inode)) 2778 workers = root->fs_info->endio_freespace_worker; 2779 else 2780 workers = root->fs_info->endio_write_workers; 2781 btrfs_queue_work(workers, &ordered_extent->work); 2782 2783 return 0; 2784 } 2785 2786 /* 2787 * when reads are done, we need to check csums to verify the data is correct 2788 * if there's a match, we allow the bio to finish. If not, the code in 2789 * extent_io.c will try to find good copies for us. 2790 */ 2791 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 2792 u64 phy_offset, struct page *page, 2793 u64 start, u64 end, int mirror) 2794 { 2795 size_t offset = start - page_offset(page); 2796 struct inode *inode = page->mapping->host; 2797 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2798 char *kaddr; 2799 struct btrfs_root *root = BTRFS_I(inode)->root; 2800 u32 csum_expected; 2801 u32 csum = ~(u32)0; 2802 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 2803 DEFAULT_RATELIMIT_BURST); 2804 2805 if (PageChecked(page)) { 2806 ClearPageChecked(page); 2807 goto good; 2808 } 2809 2810 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 2811 goto good; 2812 2813 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 2814 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 2815 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, 2816 GFP_NOFS); 2817 return 0; 2818 } 2819 2820 phy_offset >>= inode->i_sb->s_blocksize_bits; 2821 csum_expected = *(((u32 *)io_bio->csum) + phy_offset); 2822 2823 kaddr = kmap_atomic(page); 2824 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1); 2825 btrfs_csum_final(csum, (char *)&csum); 2826 if (csum != csum_expected) 2827 goto zeroit; 2828 2829 kunmap_atomic(kaddr); 2830 good: 2831 return 0; 2832 2833 zeroit: 2834 if (__ratelimit(&_rs)) 2835 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u", 2836 btrfs_ino(page->mapping->host), start, csum, csum_expected); 2837 memset(kaddr + offset, 1, end - start + 1); 2838 flush_dcache_page(page); 2839 kunmap_atomic(kaddr); 2840 if (csum_expected == 0) 2841 return 0; 2842 return -EIO; 2843 } 2844 2845 struct delayed_iput { 2846 struct list_head list; 2847 struct inode *inode; 2848 }; 2849 2850 /* JDM: If this is fs-wide, why can't we add a pointer to 2851 * btrfs_inode instead and avoid the allocation? */ 2852 void btrfs_add_delayed_iput(struct inode *inode) 2853 { 2854 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; 2855 struct delayed_iput *delayed; 2856 2857 if (atomic_add_unless(&inode->i_count, -1, 1)) 2858 return; 2859 2860 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); 2861 delayed->inode = inode; 2862 2863 spin_lock(&fs_info->delayed_iput_lock); 2864 list_add_tail(&delayed->list, &fs_info->delayed_iputs); 2865 spin_unlock(&fs_info->delayed_iput_lock); 2866 } 2867 2868 void btrfs_run_delayed_iputs(struct btrfs_root *root) 2869 { 2870 LIST_HEAD(list); 2871 struct btrfs_fs_info *fs_info = root->fs_info; 2872 struct delayed_iput *delayed; 2873 int empty; 2874 2875 spin_lock(&fs_info->delayed_iput_lock); 2876 empty = list_empty(&fs_info->delayed_iputs); 2877 spin_unlock(&fs_info->delayed_iput_lock); 2878 if (empty) 2879 return; 2880 2881 spin_lock(&fs_info->delayed_iput_lock); 2882 list_splice_init(&fs_info->delayed_iputs, &list); 2883 spin_unlock(&fs_info->delayed_iput_lock); 2884 2885 while (!list_empty(&list)) { 2886 delayed = list_entry(list.next, struct delayed_iput, list); 2887 list_del(&delayed->list); 2888 iput(delayed->inode); 2889 kfree(delayed); 2890 } 2891 } 2892 2893 /* 2894 * This is called in transaction commit time. If there are no orphan 2895 * files in the subvolume, it removes orphan item and frees block_rsv 2896 * structure. 2897 */ 2898 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 2899 struct btrfs_root *root) 2900 { 2901 struct btrfs_block_rsv *block_rsv; 2902 int ret; 2903 2904 if (atomic_read(&root->orphan_inodes) || 2905 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 2906 return; 2907 2908 spin_lock(&root->orphan_lock); 2909 if (atomic_read(&root->orphan_inodes)) { 2910 spin_unlock(&root->orphan_lock); 2911 return; 2912 } 2913 2914 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 2915 spin_unlock(&root->orphan_lock); 2916 return; 2917 } 2918 2919 block_rsv = root->orphan_block_rsv; 2920 root->orphan_block_rsv = NULL; 2921 spin_unlock(&root->orphan_lock); 2922 2923 if (root->orphan_item_inserted && 2924 btrfs_root_refs(&root->root_item) > 0) { 2925 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, 2926 root->root_key.objectid); 2927 if (ret) 2928 btrfs_abort_transaction(trans, root, ret); 2929 else 2930 root->orphan_item_inserted = 0; 2931 } 2932 2933 if (block_rsv) { 2934 WARN_ON(block_rsv->size > 0); 2935 btrfs_free_block_rsv(root, block_rsv); 2936 } 2937 } 2938 2939 /* 2940 * This creates an orphan entry for the given inode in case something goes 2941 * wrong in the middle of an unlink/truncate. 2942 * 2943 * NOTE: caller of this function should reserve 5 units of metadata for 2944 * this function. 2945 */ 2946 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) 2947 { 2948 struct btrfs_root *root = BTRFS_I(inode)->root; 2949 struct btrfs_block_rsv *block_rsv = NULL; 2950 int reserve = 0; 2951 int insert = 0; 2952 int ret; 2953 2954 if (!root->orphan_block_rsv) { 2955 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 2956 if (!block_rsv) 2957 return -ENOMEM; 2958 } 2959 2960 spin_lock(&root->orphan_lock); 2961 if (!root->orphan_block_rsv) { 2962 root->orphan_block_rsv = block_rsv; 2963 } else if (block_rsv) { 2964 btrfs_free_block_rsv(root, block_rsv); 2965 block_rsv = NULL; 2966 } 2967 2968 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 2969 &BTRFS_I(inode)->runtime_flags)) { 2970 #if 0 2971 /* 2972 * For proper ENOSPC handling, we should do orphan 2973 * cleanup when mounting. But this introduces backward 2974 * compatibility issue. 2975 */ 2976 if (!xchg(&root->orphan_item_inserted, 1)) 2977 insert = 2; 2978 else 2979 insert = 1; 2980 #endif 2981 insert = 1; 2982 atomic_inc(&root->orphan_inodes); 2983 } 2984 2985 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 2986 &BTRFS_I(inode)->runtime_flags)) 2987 reserve = 1; 2988 spin_unlock(&root->orphan_lock); 2989 2990 /* grab metadata reservation from transaction handle */ 2991 if (reserve) { 2992 ret = btrfs_orphan_reserve_metadata(trans, inode); 2993 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ 2994 } 2995 2996 /* insert an orphan item to track this unlinked/truncated file */ 2997 if (insert >= 1) { 2998 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 2999 if (ret) { 3000 atomic_dec(&root->orphan_inodes); 3001 if (reserve) { 3002 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3003 &BTRFS_I(inode)->runtime_flags); 3004 btrfs_orphan_release_metadata(inode); 3005 } 3006 if (ret != -EEXIST) { 3007 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3008 &BTRFS_I(inode)->runtime_flags); 3009 btrfs_abort_transaction(trans, root, ret); 3010 return ret; 3011 } 3012 } 3013 ret = 0; 3014 } 3015 3016 /* insert an orphan item to track subvolume contains orphan files */ 3017 if (insert >= 2) { 3018 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, 3019 root->root_key.objectid); 3020 if (ret && ret != -EEXIST) { 3021 btrfs_abort_transaction(trans, root, ret); 3022 return ret; 3023 } 3024 } 3025 return 0; 3026 } 3027 3028 /* 3029 * We have done the truncate/delete so we can go ahead and remove the orphan 3030 * item for this particular inode. 3031 */ 3032 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3033 struct inode *inode) 3034 { 3035 struct btrfs_root *root = BTRFS_I(inode)->root; 3036 int delete_item = 0; 3037 int release_rsv = 0; 3038 int ret = 0; 3039 3040 spin_lock(&root->orphan_lock); 3041 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3042 &BTRFS_I(inode)->runtime_flags)) 3043 delete_item = 1; 3044 3045 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3046 &BTRFS_I(inode)->runtime_flags)) 3047 release_rsv = 1; 3048 spin_unlock(&root->orphan_lock); 3049 3050 if (delete_item) { 3051 atomic_dec(&root->orphan_inodes); 3052 if (trans) 3053 ret = btrfs_del_orphan_item(trans, root, 3054 btrfs_ino(inode)); 3055 } 3056 3057 if (release_rsv) 3058 btrfs_orphan_release_metadata(inode); 3059 3060 return ret; 3061 } 3062 3063 /* 3064 * this cleans up any orphans that may be left on the list from the last use 3065 * of this root. 3066 */ 3067 int btrfs_orphan_cleanup(struct btrfs_root *root) 3068 { 3069 struct btrfs_path *path; 3070 struct extent_buffer *leaf; 3071 struct btrfs_key key, found_key; 3072 struct btrfs_trans_handle *trans; 3073 struct inode *inode; 3074 u64 last_objectid = 0; 3075 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3076 3077 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3078 return 0; 3079 3080 path = btrfs_alloc_path(); 3081 if (!path) { 3082 ret = -ENOMEM; 3083 goto out; 3084 } 3085 path->reada = -1; 3086 3087 key.objectid = BTRFS_ORPHAN_OBJECTID; 3088 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); 3089 key.offset = (u64)-1; 3090 3091 while (1) { 3092 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3093 if (ret < 0) 3094 goto out; 3095 3096 /* 3097 * if ret == 0 means we found what we were searching for, which 3098 * is weird, but possible, so only screw with path if we didn't 3099 * find the key and see if we have stuff that matches 3100 */ 3101 if (ret > 0) { 3102 ret = 0; 3103 if (path->slots[0] == 0) 3104 break; 3105 path->slots[0]--; 3106 } 3107 3108 /* pull out the item */ 3109 leaf = path->nodes[0]; 3110 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3111 3112 /* make sure the item matches what we want */ 3113 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3114 break; 3115 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY) 3116 break; 3117 3118 /* release the path since we're done with it */ 3119 btrfs_release_path(path); 3120 3121 /* 3122 * this is where we are basically btrfs_lookup, without the 3123 * crossing root thing. we store the inode number in the 3124 * offset of the orphan item. 3125 */ 3126 3127 if (found_key.offset == last_objectid) { 3128 btrfs_err(root->fs_info, 3129 "Error removing orphan entry, stopping orphan cleanup"); 3130 ret = -EINVAL; 3131 goto out; 3132 } 3133 3134 last_objectid = found_key.offset; 3135 3136 found_key.objectid = found_key.offset; 3137 found_key.type = BTRFS_INODE_ITEM_KEY; 3138 found_key.offset = 0; 3139 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); 3140 ret = PTR_ERR_OR_ZERO(inode); 3141 if (ret && ret != -ESTALE) 3142 goto out; 3143 3144 if (ret == -ESTALE && root == root->fs_info->tree_root) { 3145 struct btrfs_root *dead_root; 3146 struct btrfs_fs_info *fs_info = root->fs_info; 3147 int is_dead_root = 0; 3148 3149 /* 3150 * this is an orphan in the tree root. Currently these 3151 * could come from 2 sources: 3152 * a) a snapshot deletion in progress 3153 * b) a free space cache inode 3154 * We need to distinguish those two, as the snapshot 3155 * orphan must not get deleted. 3156 * find_dead_roots already ran before us, so if this 3157 * is a snapshot deletion, we should find the root 3158 * in the dead_roots list 3159 */ 3160 spin_lock(&fs_info->trans_lock); 3161 list_for_each_entry(dead_root, &fs_info->dead_roots, 3162 root_list) { 3163 if (dead_root->root_key.objectid == 3164 found_key.objectid) { 3165 is_dead_root = 1; 3166 break; 3167 } 3168 } 3169 spin_unlock(&fs_info->trans_lock); 3170 if (is_dead_root) { 3171 /* prevent this orphan from being found again */ 3172 key.offset = found_key.objectid - 1; 3173 continue; 3174 } 3175 } 3176 /* 3177 * Inode is already gone but the orphan item is still there, 3178 * kill the orphan item. 3179 */ 3180 if (ret == -ESTALE) { 3181 trans = btrfs_start_transaction(root, 1); 3182 if (IS_ERR(trans)) { 3183 ret = PTR_ERR(trans); 3184 goto out; 3185 } 3186 btrfs_debug(root->fs_info, "auto deleting %Lu", 3187 found_key.objectid); 3188 ret = btrfs_del_orphan_item(trans, root, 3189 found_key.objectid); 3190 btrfs_end_transaction(trans, root); 3191 if (ret) 3192 goto out; 3193 continue; 3194 } 3195 3196 /* 3197 * add this inode to the orphan list so btrfs_orphan_del does 3198 * the proper thing when we hit it 3199 */ 3200 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3201 &BTRFS_I(inode)->runtime_flags); 3202 atomic_inc(&root->orphan_inodes); 3203 3204 /* if we have links, this was a truncate, lets do that */ 3205 if (inode->i_nlink) { 3206 if (WARN_ON(!S_ISREG(inode->i_mode))) { 3207 iput(inode); 3208 continue; 3209 } 3210 nr_truncate++; 3211 3212 /* 1 for the orphan item deletion. */ 3213 trans = btrfs_start_transaction(root, 1); 3214 if (IS_ERR(trans)) { 3215 iput(inode); 3216 ret = PTR_ERR(trans); 3217 goto out; 3218 } 3219 ret = btrfs_orphan_add(trans, inode); 3220 btrfs_end_transaction(trans, root); 3221 if (ret) { 3222 iput(inode); 3223 goto out; 3224 } 3225 3226 ret = btrfs_truncate(inode); 3227 if (ret) 3228 btrfs_orphan_del(NULL, inode); 3229 } else { 3230 nr_unlink++; 3231 } 3232 3233 /* this will do delete_inode and everything for us */ 3234 iput(inode); 3235 if (ret) 3236 goto out; 3237 } 3238 /* release the path since we're done with it */ 3239 btrfs_release_path(path); 3240 3241 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3242 3243 if (root->orphan_block_rsv) 3244 btrfs_block_rsv_release(root, root->orphan_block_rsv, 3245 (u64)-1); 3246 3247 if (root->orphan_block_rsv || root->orphan_item_inserted) { 3248 trans = btrfs_join_transaction(root); 3249 if (!IS_ERR(trans)) 3250 btrfs_end_transaction(trans, root); 3251 } 3252 3253 if (nr_unlink) 3254 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); 3255 if (nr_truncate) 3256 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); 3257 3258 out: 3259 if (ret) 3260 btrfs_crit(root->fs_info, 3261 "could not do orphan cleanup %d", ret); 3262 btrfs_free_path(path); 3263 return ret; 3264 } 3265 3266 /* 3267 * very simple check to peek ahead in the leaf looking for xattrs. If we 3268 * don't find any xattrs, we know there can't be any acls. 3269 * 3270 * slot is the slot the inode is in, objectid is the objectid of the inode 3271 */ 3272 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3273 int slot, u64 objectid, 3274 int *first_xattr_slot) 3275 { 3276 u32 nritems = btrfs_header_nritems(leaf); 3277 struct btrfs_key found_key; 3278 static u64 xattr_access = 0; 3279 static u64 xattr_default = 0; 3280 int scanned = 0; 3281 3282 if (!xattr_access) { 3283 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS, 3284 strlen(POSIX_ACL_XATTR_ACCESS)); 3285 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT, 3286 strlen(POSIX_ACL_XATTR_DEFAULT)); 3287 } 3288 3289 slot++; 3290 *first_xattr_slot = -1; 3291 while (slot < nritems) { 3292 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3293 3294 /* we found a different objectid, there must not be acls */ 3295 if (found_key.objectid != objectid) 3296 return 0; 3297 3298 /* we found an xattr, assume we've got an acl */ 3299 if (found_key.type == BTRFS_XATTR_ITEM_KEY) { 3300 if (*first_xattr_slot == -1) 3301 *first_xattr_slot = slot; 3302 if (found_key.offset == xattr_access || 3303 found_key.offset == xattr_default) 3304 return 1; 3305 } 3306 3307 /* 3308 * we found a key greater than an xattr key, there can't 3309 * be any acls later on 3310 */ 3311 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3312 return 0; 3313 3314 slot++; 3315 scanned++; 3316 3317 /* 3318 * it goes inode, inode backrefs, xattrs, extents, 3319 * so if there are a ton of hard links to an inode there can 3320 * be a lot of backrefs. Don't waste time searching too hard, 3321 * this is just an optimization 3322 */ 3323 if (scanned >= 8) 3324 break; 3325 } 3326 /* we hit the end of the leaf before we found an xattr or 3327 * something larger than an xattr. We have to assume the inode 3328 * has acls 3329 */ 3330 if (*first_xattr_slot == -1) 3331 *first_xattr_slot = slot; 3332 return 1; 3333 } 3334 3335 /* 3336 * read an inode from the btree into the in-memory inode 3337 */ 3338 static void btrfs_read_locked_inode(struct inode *inode) 3339 { 3340 struct btrfs_path *path; 3341 struct extent_buffer *leaf; 3342 struct btrfs_inode_item *inode_item; 3343 struct btrfs_timespec *tspec; 3344 struct btrfs_root *root = BTRFS_I(inode)->root; 3345 struct btrfs_key location; 3346 unsigned long ptr; 3347 int maybe_acls; 3348 u32 rdev; 3349 int ret; 3350 bool filled = false; 3351 int first_xattr_slot; 3352 3353 ret = btrfs_fill_inode(inode, &rdev); 3354 if (!ret) 3355 filled = true; 3356 3357 path = btrfs_alloc_path(); 3358 if (!path) 3359 goto make_bad; 3360 3361 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3362 3363 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3364 if (ret) 3365 goto make_bad; 3366 3367 leaf = path->nodes[0]; 3368 3369 if (filled) 3370 goto cache_index; 3371 3372 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3373 struct btrfs_inode_item); 3374 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3375 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3376 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3377 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3378 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); 3379 3380 tspec = btrfs_inode_atime(inode_item); 3381 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3382 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3383 3384 tspec = btrfs_inode_mtime(inode_item); 3385 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3386 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3387 3388 tspec = btrfs_inode_ctime(inode_item); 3389 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3390 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3391 3392 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3393 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3394 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3395 3396 /* 3397 * If we were modified in the current generation and evicted from memory 3398 * and then re-read we need to do a full sync since we don't have any 3399 * idea about which extents were modified before we were evicted from 3400 * cache. 3401 */ 3402 if (BTRFS_I(inode)->last_trans == root->fs_info->generation) 3403 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3404 &BTRFS_I(inode)->runtime_flags); 3405 3406 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3407 inode->i_generation = BTRFS_I(inode)->generation; 3408 inode->i_rdev = 0; 3409 rdev = btrfs_inode_rdev(leaf, inode_item); 3410 3411 BTRFS_I(inode)->index_cnt = (u64)-1; 3412 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3413 3414 cache_index: 3415 path->slots[0]++; 3416 if (inode->i_nlink != 1 || 3417 path->slots[0] >= btrfs_header_nritems(leaf)) 3418 goto cache_acl; 3419 3420 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); 3421 if (location.objectid != btrfs_ino(inode)) 3422 goto cache_acl; 3423 3424 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 3425 if (location.type == BTRFS_INODE_REF_KEY) { 3426 struct btrfs_inode_ref *ref; 3427 3428 ref = (struct btrfs_inode_ref *)ptr; 3429 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); 3430 } else if (location.type == BTRFS_INODE_EXTREF_KEY) { 3431 struct btrfs_inode_extref *extref; 3432 3433 extref = (struct btrfs_inode_extref *)ptr; 3434 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, 3435 extref); 3436 } 3437 cache_acl: 3438 /* 3439 * try to precache a NULL acl entry for files that don't have 3440 * any xattrs or acls 3441 */ 3442 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3443 btrfs_ino(inode), &first_xattr_slot); 3444 if (first_xattr_slot != -1) { 3445 path->slots[0] = first_xattr_slot; 3446 ret = btrfs_load_inode_props(inode, path); 3447 if (ret) 3448 btrfs_err(root->fs_info, 3449 "error loading props for ino %llu (root %llu): %d\n", 3450 btrfs_ino(inode), 3451 root->root_key.objectid, ret); 3452 } 3453 btrfs_free_path(path); 3454 3455 if (!maybe_acls) 3456 cache_no_acl(inode); 3457 3458 switch (inode->i_mode & S_IFMT) { 3459 case S_IFREG: 3460 inode->i_mapping->a_ops = &btrfs_aops; 3461 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3462 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3463 inode->i_fop = &btrfs_file_operations; 3464 inode->i_op = &btrfs_file_inode_operations; 3465 break; 3466 case S_IFDIR: 3467 inode->i_fop = &btrfs_dir_file_operations; 3468 if (root == root->fs_info->tree_root) 3469 inode->i_op = &btrfs_dir_ro_inode_operations; 3470 else 3471 inode->i_op = &btrfs_dir_inode_operations; 3472 break; 3473 case S_IFLNK: 3474 inode->i_op = &btrfs_symlink_inode_operations; 3475 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3476 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3477 break; 3478 default: 3479 inode->i_op = &btrfs_special_inode_operations; 3480 init_special_inode(inode, inode->i_mode, rdev); 3481 break; 3482 } 3483 3484 btrfs_update_iflags(inode); 3485 return; 3486 3487 make_bad: 3488 btrfs_free_path(path); 3489 make_bad_inode(inode); 3490 } 3491 3492 /* 3493 * given a leaf and an inode, copy the inode fields into the leaf 3494 */ 3495 static void fill_inode_item(struct btrfs_trans_handle *trans, 3496 struct extent_buffer *leaf, 3497 struct btrfs_inode_item *item, 3498 struct inode *inode) 3499 { 3500 struct btrfs_map_token token; 3501 3502 btrfs_init_map_token(&token); 3503 3504 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3505 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3506 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3507 &token); 3508 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3509 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3510 3511 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item), 3512 inode->i_atime.tv_sec, &token); 3513 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item), 3514 inode->i_atime.tv_nsec, &token); 3515 3516 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item), 3517 inode->i_mtime.tv_sec, &token); 3518 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item), 3519 inode->i_mtime.tv_nsec, &token); 3520 3521 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item), 3522 inode->i_ctime.tv_sec, &token); 3523 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item), 3524 inode->i_ctime.tv_nsec, &token); 3525 3526 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3527 &token); 3528 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3529 &token); 3530 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3531 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3532 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3533 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3534 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3535 } 3536 3537 /* 3538 * copy everything in the in-memory inode into the btree. 3539 */ 3540 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3541 struct btrfs_root *root, struct inode *inode) 3542 { 3543 struct btrfs_inode_item *inode_item; 3544 struct btrfs_path *path; 3545 struct extent_buffer *leaf; 3546 int ret; 3547 3548 path = btrfs_alloc_path(); 3549 if (!path) 3550 return -ENOMEM; 3551 3552 path->leave_spinning = 1; 3553 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3554 1); 3555 if (ret) { 3556 if (ret > 0) 3557 ret = -ENOENT; 3558 goto failed; 3559 } 3560 3561 leaf = path->nodes[0]; 3562 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3563 struct btrfs_inode_item); 3564 3565 fill_inode_item(trans, leaf, inode_item, inode); 3566 btrfs_mark_buffer_dirty(leaf); 3567 btrfs_set_inode_last_trans(trans, inode); 3568 ret = 0; 3569 failed: 3570 btrfs_free_path(path); 3571 return ret; 3572 } 3573 3574 /* 3575 * copy everything in the in-memory inode into the btree. 3576 */ 3577 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3578 struct btrfs_root *root, struct inode *inode) 3579 { 3580 int ret; 3581 3582 /* 3583 * If the inode is a free space inode, we can deadlock during commit 3584 * if we put it into the delayed code. 3585 * 3586 * The data relocation inode should also be directly updated 3587 * without delay 3588 */ 3589 if (!btrfs_is_free_space_inode(inode) 3590 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) { 3591 btrfs_update_root_times(trans, root); 3592 3593 ret = btrfs_delayed_update_inode(trans, root, inode); 3594 if (!ret) 3595 btrfs_set_inode_last_trans(trans, inode); 3596 return ret; 3597 } 3598 3599 return btrfs_update_inode_item(trans, root, inode); 3600 } 3601 3602 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3603 struct btrfs_root *root, 3604 struct inode *inode) 3605 { 3606 int ret; 3607 3608 ret = btrfs_update_inode(trans, root, inode); 3609 if (ret == -ENOSPC) 3610 return btrfs_update_inode_item(trans, root, inode); 3611 return ret; 3612 } 3613 3614 /* 3615 * unlink helper that gets used here in inode.c and in the tree logging 3616 * recovery code. It remove a link in a directory with a given name, and 3617 * also drops the back refs in the inode to the directory 3618 */ 3619 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3620 struct btrfs_root *root, 3621 struct inode *dir, struct inode *inode, 3622 const char *name, int name_len) 3623 { 3624 struct btrfs_path *path; 3625 int ret = 0; 3626 struct extent_buffer *leaf; 3627 struct btrfs_dir_item *di; 3628 struct btrfs_key key; 3629 u64 index; 3630 u64 ino = btrfs_ino(inode); 3631 u64 dir_ino = btrfs_ino(dir); 3632 3633 path = btrfs_alloc_path(); 3634 if (!path) { 3635 ret = -ENOMEM; 3636 goto out; 3637 } 3638 3639 path->leave_spinning = 1; 3640 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3641 name, name_len, -1); 3642 if (IS_ERR(di)) { 3643 ret = PTR_ERR(di); 3644 goto err; 3645 } 3646 if (!di) { 3647 ret = -ENOENT; 3648 goto err; 3649 } 3650 leaf = path->nodes[0]; 3651 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3652 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3653 if (ret) 3654 goto err; 3655 btrfs_release_path(path); 3656 3657 /* 3658 * If we don't have dir index, we have to get it by looking up 3659 * the inode ref, since we get the inode ref, remove it directly, 3660 * it is unnecessary to do delayed deletion. 3661 * 3662 * But if we have dir index, needn't search inode ref to get it. 3663 * Since the inode ref is close to the inode item, it is better 3664 * that we delay to delete it, and just do this deletion when 3665 * we update the inode item. 3666 */ 3667 if (BTRFS_I(inode)->dir_index) { 3668 ret = btrfs_delayed_delete_inode_ref(inode); 3669 if (!ret) { 3670 index = BTRFS_I(inode)->dir_index; 3671 goto skip_backref; 3672 } 3673 } 3674 3675 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3676 dir_ino, &index); 3677 if (ret) { 3678 btrfs_info(root->fs_info, 3679 "failed to delete reference to %.*s, inode %llu parent %llu", 3680 name_len, name, ino, dir_ino); 3681 btrfs_abort_transaction(trans, root, ret); 3682 goto err; 3683 } 3684 skip_backref: 3685 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3686 if (ret) { 3687 btrfs_abort_transaction(trans, root, ret); 3688 goto err; 3689 } 3690 3691 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, 3692 inode, dir_ino); 3693 if (ret != 0 && ret != -ENOENT) { 3694 btrfs_abort_transaction(trans, root, ret); 3695 goto err; 3696 } 3697 3698 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, 3699 dir, index); 3700 if (ret == -ENOENT) 3701 ret = 0; 3702 else if (ret) 3703 btrfs_abort_transaction(trans, root, ret); 3704 err: 3705 btrfs_free_path(path); 3706 if (ret) 3707 goto out; 3708 3709 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3710 inode_inc_iversion(inode); 3711 inode_inc_iversion(dir); 3712 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3713 ret = btrfs_update_inode(trans, root, dir); 3714 out: 3715 return ret; 3716 } 3717 3718 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3719 struct btrfs_root *root, 3720 struct inode *dir, struct inode *inode, 3721 const char *name, int name_len) 3722 { 3723 int ret; 3724 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 3725 if (!ret) { 3726 drop_nlink(inode); 3727 ret = btrfs_update_inode(trans, root, inode); 3728 } 3729 return ret; 3730 } 3731 3732 /* 3733 * helper to start transaction for unlink and rmdir. 3734 * 3735 * unlink and rmdir are special in btrfs, they do not always free space, so 3736 * if we cannot make our reservations the normal way try and see if there is 3737 * plenty of slack room in the global reserve to migrate, otherwise we cannot 3738 * allow the unlink to occur. 3739 */ 3740 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) 3741 { 3742 struct btrfs_trans_handle *trans; 3743 struct btrfs_root *root = BTRFS_I(dir)->root; 3744 int ret; 3745 3746 /* 3747 * 1 for the possible orphan item 3748 * 1 for the dir item 3749 * 1 for the dir index 3750 * 1 for the inode ref 3751 * 1 for the inode 3752 */ 3753 trans = btrfs_start_transaction(root, 5); 3754 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) 3755 return trans; 3756 3757 if (PTR_ERR(trans) == -ENOSPC) { 3758 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5); 3759 3760 trans = btrfs_start_transaction(root, 0); 3761 if (IS_ERR(trans)) 3762 return trans; 3763 ret = btrfs_cond_migrate_bytes(root->fs_info, 3764 &root->fs_info->trans_block_rsv, 3765 num_bytes, 5); 3766 if (ret) { 3767 btrfs_end_transaction(trans, root); 3768 return ERR_PTR(ret); 3769 } 3770 trans->block_rsv = &root->fs_info->trans_block_rsv; 3771 trans->bytes_reserved = num_bytes; 3772 } 3773 return trans; 3774 } 3775 3776 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 3777 { 3778 struct btrfs_root *root = BTRFS_I(dir)->root; 3779 struct btrfs_trans_handle *trans; 3780 struct inode *inode = dentry->d_inode; 3781 int ret; 3782 3783 trans = __unlink_start_trans(dir); 3784 if (IS_ERR(trans)) 3785 return PTR_ERR(trans); 3786 3787 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0); 3788 3789 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3790 dentry->d_name.name, dentry->d_name.len); 3791 if (ret) 3792 goto out; 3793 3794 if (inode->i_nlink == 0) { 3795 ret = btrfs_orphan_add(trans, inode); 3796 if (ret) 3797 goto out; 3798 } 3799 3800 out: 3801 btrfs_end_transaction(trans, root); 3802 btrfs_btree_balance_dirty(root); 3803 return ret; 3804 } 3805 3806 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 3807 struct btrfs_root *root, 3808 struct inode *dir, u64 objectid, 3809 const char *name, int name_len) 3810 { 3811 struct btrfs_path *path; 3812 struct extent_buffer *leaf; 3813 struct btrfs_dir_item *di; 3814 struct btrfs_key key; 3815 u64 index; 3816 int ret; 3817 u64 dir_ino = btrfs_ino(dir); 3818 3819 path = btrfs_alloc_path(); 3820 if (!path) 3821 return -ENOMEM; 3822 3823 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3824 name, name_len, -1); 3825 if (IS_ERR_OR_NULL(di)) { 3826 if (!di) 3827 ret = -ENOENT; 3828 else 3829 ret = PTR_ERR(di); 3830 goto out; 3831 } 3832 3833 leaf = path->nodes[0]; 3834 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3835 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 3836 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3837 if (ret) { 3838 btrfs_abort_transaction(trans, root, ret); 3839 goto out; 3840 } 3841 btrfs_release_path(path); 3842 3843 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, 3844 objectid, root->root_key.objectid, 3845 dir_ino, &index, name, name_len); 3846 if (ret < 0) { 3847 if (ret != -ENOENT) { 3848 btrfs_abort_transaction(trans, root, ret); 3849 goto out; 3850 } 3851 di = btrfs_search_dir_index_item(root, path, dir_ino, 3852 name, name_len); 3853 if (IS_ERR_OR_NULL(di)) { 3854 if (!di) 3855 ret = -ENOENT; 3856 else 3857 ret = PTR_ERR(di); 3858 btrfs_abort_transaction(trans, root, ret); 3859 goto out; 3860 } 3861 3862 leaf = path->nodes[0]; 3863 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3864 btrfs_release_path(path); 3865 index = key.offset; 3866 } 3867 btrfs_release_path(path); 3868 3869 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3870 if (ret) { 3871 btrfs_abort_transaction(trans, root, ret); 3872 goto out; 3873 } 3874 3875 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3876 inode_inc_iversion(dir); 3877 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3878 ret = btrfs_update_inode_fallback(trans, root, dir); 3879 if (ret) 3880 btrfs_abort_transaction(trans, root, ret); 3881 out: 3882 btrfs_free_path(path); 3883 return ret; 3884 } 3885 3886 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 3887 { 3888 struct inode *inode = dentry->d_inode; 3889 int err = 0; 3890 struct btrfs_root *root = BTRFS_I(dir)->root; 3891 struct btrfs_trans_handle *trans; 3892 3893 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 3894 return -ENOTEMPTY; 3895 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) 3896 return -EPERM; 3897 3898 trans = __unlink_start_trans(dir); 3899 if (IS_ERR(trans)) 3900 return PTR_ERR(trans); 3901 3902 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 3903 err = btrfs_unlink_subvol(trans, root, dir, 3904 BTRFS_I(inode)->location.objectid, 3905 dentry->d_name.name, 3906 dentry->d_name.len); 3907 goto out; 3908 } 3909 3910 err = btrfs_orphan_add(trans, inode); 3911 if (err) 3912 goto out; 3913 3914 /* now the directory is empty */ 3915 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3916 dentry->d_name.name, dentry->d_name.len); 3917 if (!err) 3918 btrfs_i_size_write(inode, 0); 3919 out: 3920 btrfs_end_transaction(trans, root); 3921 btrfs_btree_balance_dirty(root); 3922 3923 return err; 3924 } 3925 3926 /* 3927 * this can truncate away extent items, csum items and directory items. 3928 * It starts at a high offset and removes keys until it can't find 3929 * any higher than new_size 3930 * 3931 * csum items that cross the new i_size are truncated to the new size 3932 * as well. 3933 * 3934 * min_type is the minimum key type to truncate down to. If set to 0, this 3935 * will kill all the items on this inode, including the INODE_ITEM_KEY. 3936 */ 3937 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 3938 struct btrfs_root *root, 3939 struct inode *inode, 3940 u64 new_size, u32 min_type) 3941 { 3942 struct btrfs_path *path; 3943 struct extent_buffer *leaf; 3944 struct btrfs_file_extent_item *fi; 3945 struct btrfs_key key; 3946 struct btrfs_key found_key; 3947 u64 extent_start = 0; 3948 u64 extent_num_bytes = 0; 3949 u64 extent_offset = 0; 3950 u64 item_end = 0; 3951 u64 last_size = (u64)-1; 3952 u32 found_type = (u8)-1; 3953 int found_extent; 3954 int del_item; 3955 int pending_del_nr = 0; 3956 int pending_del_slot = 0; 3957 int extent_type = -1; 3958 int ret; 3959 int err = 0; 3960 u64 ino = btrfs_ino(inode); 3961 3962 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 3963 3964 path = btrfs_alloc_path(); 3965 if (!path) 3966 return -ENOMEM; 3967 path->reada = -1; 3968 3969 /* 3970 * We want to drop from the next block forward in case this new size is 3971 * not block aligned since we will be keeping the last block of the 3972 * extent just the way it is. 3973 */ 3974 if (root->ref_cows || root == root->fs_info->tree_root) 3975 btrfs_drop_extent_cache(inode, ALIGN(new_size, 3976 root->sectorsize), (u64)-1, 0); 3977 3978 /* 3979 * This function is also used to drop the items in the log tree before 3980 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 3981 * it is used to drop the loged items. So we shouldn't kill the delayed 3982 * items. 3983 */ 3984 if (min_type == 0 && root == BTRFS_I(inode)->root) 3985 btrfs_kill_delayed_inode_items(inode); 3986 3987 key.objectid = ino; 3988 key.offset = (u64)-1; 3989 key.type = (u8)-1; 3990 3991 search_again: 3992 path->leave_spinning = 1; 3993 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 3994 if (ret < 0) { 3995 err = ret; 3996 goto out; 3997 } 3998 3999 if (ret > 0) { 4000 /* there are no items in the tree for us to truncate, we're 4001 * done 4002 */ 4003 if (path->slots[0] == 0) 4004 goto out; 4005 path->slots[0]--; 4006 } 4007 4008 while (1) { 4009 fi = NULL; 4010 leaf = path->nodes[0]; 4011 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4012 found_type = btrfs_key_type(&found_key); 4013 4014 if (found_key.objectid != ino) 4015 break; 4016 4017 if (found_type < min_type) 4018 break; 4019 4020 item_end = found_key.offset; 4021 if (found_type == BTRFS_EXTENT_DATA_KEY) { 4022 fi = btrfs_item_ptr(leaf, path->slots[0], 4023 struct btrfs_file_extent_item); 4024 extent_type = btrfs_file_extent_type(leaf, fi); 4025 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4026 item_end += 4027 btrfs_file_extent_num_bytes(leaf, fi); 4028 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4029 item_end += btrfs_file_extent_inline_len(leaf, 4030 path->slots[0], fi); 4031 } 4032 item_end--; 4033 } 4034 if (found_type > min_type) { 4035 del_item = 1; 4036 } else { 4037 if (item_end < new_size) 4038 break; 4039 if (found_key.offset >= new_size) 4040 del_item = 1; 4041 else 4042 del_item = 0; 4043 } 4044 found_extent = 0; 4045 /* FIXME, shrink the extent if the ref count is only 1 */ 4046 if (found_type != BTRFS_EXTENT_DATA_KEY) 4047 goto delete; 4048 4049 if (del_item) 4050 last_size = found_key.offset; 4051 else 4052 last_size = new_size; 4053 4054 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4055 u64 num_dec; 4056 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4057 if (!del_item) { 4058 u64 orig_num_bytes = 4059 btrfs_file_extent_num_bytes(leaf, fi); 4060 extent_num_bytes = ALIGN(new_size - 4061 found_key.offset, 4062 root->sectorsize); 4063 btrfs_set_file_extent_num_bytes(leaf, fi, 4064 extent_num_bytes); 4065 num_dec = (orig_num_bytes - 4066 extent_num_bytes); 4067 if (root->ref_cows && extent_start != 0) 4068 inode_sub_bytes(inode, num_dec); 4069 btrfs_mark_buffer_dirty(leaf); 4070 } else { 4071 extent_num_bytes = 4072 btrfs_file_extent_disk_num_bytes(leaf, 4073 fi); 4074 extent_offset = found_key.offset - 4075 btrfs_file_extent_offset(leaf, fi); 4076 4077 /* FIXME blocksize != 4096 */ 4078 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4079 if (extent_start != 0) { 4080 found_extent = 1; 4081 if (root->ref_cows) 4082 inode_sub_bytes(inode, num_dec); 4083 } 4084 } 4085 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4086 /* 4087 * we can't truncate inline items that have had 4088 * special encodings 4089 */ 4090 if (!del_item && 4091 btrfs_file_extent_compression(leaf, fi) == 0 && 4092 btrfs_file_extent_encryption(leaf, fi) == 0 && 4093 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4094 u32 size = new_size - found_key.offset; 4095 4096 if (root->ref_cows) { 4097 inode_sub_bytes(inode, item_end + 1 - 4098 new_size); 4099 } 4100 4101 /* 4102 * update the ram bytes to properly reflect 4103 * the new size of our item 4104 */ 4105 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 4106 size = 4107 btrfs_file_extent_calc_inline_size(size); 4108 btrfs_truncate_item(root, path, size, 1); 4109 } else if (root->ref_cows) { 4110 inode_sub_bytes(inode, item_end + 1 - 4111 found_key.offset); 4112 } 4113 } 4114 delete: 4115 if (del_item) { 4116 if (!pending_del_nr) { 4117 /* no pending yet, add ourselves */ 4118 pending_del_slot = path->slots[0]; 4119 pending_del_nr = 1; 4120 } else if (pending_del_nr && 4121 path->slots[0] + 1 == pending_del_slot) { 4122 /* hop on the pending chunk */ 4123 pending_del_nr++; 4124 pending_del_slot = path->slots[0]; 4125 } else { 4126 BUG(); 4127 } 4128 } else { 4129 break; 4130 } 4131 if (found_extent && (root->ref_cows || 4132 root == root->fs_info->tree_root)) { 4133 btrfs_set_path_blocking(path); 4134 ret = btrfs_free_extent(trans, root, extent_start, 4135 extent_num_bytes, 0, 4136 btrfs_header_owner(leaf), 4137 ino, extent_offset, 0); 4138 BUG_ON(ret); 4139 } 4140 4141 if (found_type == BTRFS_INODE_ITEM_KEY) 4142 break; 4143 4144 if (path->slots[0] == 0 || 4145 path->slots[0] != pending_del_slot) { 4146 if (pending_del_nr) { 4147 ret = btrfs_del_items(trans, root, path, 4148 pending_del_slot, 4149 pending_del_nr); 4150 if (ret) { 4151 btrfs_abort_transaction(trans, 4152 root, ret); 4153 goto error; 4154 } 4155 pending_del_nr = 0; 4156 } 4157 btrfs_release_path(path); 4158 goto search_again; 4159 } else { 4160 path->slots[0]--; 4161 } 4162 } 4163 out: 4164 if (pending_del_nr) { 4165 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4166 pending_del_nr); 4167 if (ret) 4168 btrfs_abort_transaction(trans, root, ret); 4169 } 4170 error: 4171 if (last_size != (u64)-1) 4172 btrfs_ordered_update_i_size(inode, last_size, NULL); 4173 btrfs_free_path(path); 4174 return err; 4175 } 4176 4177 /* 4178 * btrfs_truncate_page - read, zero a chunk and write a page 4179 * @inode - inode that we're zeroing 4180 * @from - the offset to start zeroing 4181 * @len - the length to zero, 0 to zero the entire range respective to the 4182 * offset 4183 * @front - zero up to the offset instead of from the offset on 4184 * 4185 * This will find the page for the "from" offset and cow the page and zero the 4186 * part we want to zero. This is used with truncate and hole punching. 4187 */ 4188 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, 4189 int front) 4190 { 4191 struct address_space *mapping = inode->i_mapping; 4192 struct btrfs_root *root = BTRFS_I(inode)->root; 4193 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4194 struct btrfs_ordered_extent *ordered; 4195 struct extent_state *cached_state = NULL; 4196 char *kaddr; 4197 u32 blocksize = root->sectorsize; 4198 pgoff_t index = from >> PAGE_CACHE_SHIFT; 4199 unsigned offset = from & (PAGE_CACHE_SIZE-1); 4200 struct page *page; 4201 gfp_t mask = btrfs_alloc_write_mask(mapping); 4202 int ret = 0; 4203 u64 page_start; 4204 u64 page_end; 4205 4206 if ((offset & (blocksize - 1)) == 0 && 4207 (!len || ((len & (blocksize - 1)) == 0))) 4208 goto out; 4209 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 4210 if (ret) 4211 goto out; 4212 4213 again: 4214 page = find_or_create_page(mapping, index, mask); 4215 if (!page) { 4216 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4217 ret = -ENOMEM; 4218 goto out; 4219 } 4220 4221 page_start = page_offset(page); 4222 page_end = page_start + PAGE_CACHE_SIZE - 1; 4223 4224 if (!PageUptodate(page)) { 4225 ret = btrfs_readpage(NULL, page); 4226 lock_page(page); 4227 if (page->mapping != mapping) { 4228 unlock_page(page); 4229 page_cache_release(page); 4230 goto again; 4231 } 4232 if (!PageUptodate(page)) { 4233 ret = -EIO; 4234 goto out_unlock; 4235 } 4236 } 4237 wait_on_page_writeback(page); 4238 4239 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 4240 set_page_extent_mapped(page); 4241 4242 ordered = btrfs_lookup_ordered_extent(inode, page_start); 4243 if (ordered) { 4244 unlock_extent_cached(io_tree, page_start, page_end, 4245 &cached_state, GFP_NOFS); 4246 unlock_page(page); 4247 page_cache_release(page); 4248 btrfs_start_ordered_extent(inode, ordered, 1); 4249 btrfs_put_ordered_extent(ordered); 4250 goto again; 4251 } 4252 4253 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 4254 EXTENT_DIRTY | EXTENT_DELALLOC | 4255 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4256 0, 0, &cached_state, GFP_NOFS); 4257 4258 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 4259 &cached_state); 4260 if (ret) { 4261 unlock_extent_cached(io_tree, page_start, page_end, 4262 &cached_state, GFP_NOFS); 4263 goto out_unlock; 4264 } 4265 4266 if (offset != PAGE_CACHE_SIZE) { 4267 if (!len) 4268 len = PAGE_CACHE_SIZE - offset; 4269 kaddr = kmap(page); 4270 if (front) 4271 memset(kaddr, 0, offset); 4272 else 4273 memset(kaddr + offset, 0, len); 4274 flush_dcache_page(page); 4275 kunmap(page); 4276 } 4277 ClearPageChecked(page); 4278 set_page_dirty(page); 4279 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, 4280 GFP_NOFS); 4281 4282 out_unlock: 4283 if (ret) 4284 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4285 unlock_page(page); 4286 page_cache_release(page); 4287 out: 4288 return ret; 4289 } 4290 4291 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, 4292 u64 offset, u64 len) 4293 { 4294 struct btrfs_trans_handle *trans; 4295 int ret; 4296 4297 /* 4298 * Still need to make sure the inode looks like it's been updated so 4299 * that any holes get logged if we fsync. 4300 */ 4301 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) { 4302 BTRFS_I(inode)->last_trans = root->fs_info->generation; 4303 BTRFS_I(inode)->last_sub_trans = root->log_transid; 4304 BTRFS_I(inode)->last_log_commit = root->last_log_commit; 4305 return 0; 4306 } 4307 4308 /* 4309 * 1 - for the one we're dropping 4310 * 1 - for the one we're adding 4311 * 1 - for updating the inode. 4312 */ 4313 trans = btrfs_start_transaction(root, 3); 4314 if (IS_ERR(trans)) 4315 return PTR_ERR(trans); 4316 4317 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); 4318 if (ret) { 4319 btrfs_abort_transaction(trans, root, ret); 4320 btrfs_end_transaction(trans, root); 4321 return ret; 4322 } 4323 4324 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, 4325 0, 0, len, 0, len, 0, 0, 0); 4326 if (ret) 4327 btrfs_abort_transaction(trans, root, ret); 4328 else 4329 btrfs_update_inode(trans, root, inode); 4330 btrfs_end_transaction(trans, root); 4331 return ret; 4332 } 4333 4334 /* 4335 * This function puts in dummy file extents for the area we're creating a hole 4336 * for. So if we are truncating this file to a larger size we need to insert 4337 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4338 * the range between oldsize and size 4339 */ 4340 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4341 { 4342 struct btrfs_root *root = BTRFS_I(inode)->root; 4343 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4344 struct extent_map *em = NULL; 4345 struct extent_state *cached_state = NULL; 4346 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4347 u64 hole_start = ALIGN(oldsize, root->sectorsize); 4348 u64 block_end = ALIGN(size, root->sectorsize); 4349 u64 last_byte; 4350 u64 cur_offset; 4351 u64 hole_size; 4352 int err = 0; 4353 4354 /* 4355 * If our size started in the middle of a page we need to zero out the 4356 * rest of the page before we expand the i_size, otherwise we could 4357 * expose stale data. 4358 */ 4359 err = btrfs_truncate_page(inode, oldsize, 0, 0); 4360 if (err) 4361 return err; 4362 4363 if (size <= hole_start) 4364 return 0; 4365 4366 while (1) { 4367 struct btrfs_ordered_extent *ordered; 4368 4369 lock_extent_bits(io_tree, hole_start, block_end - 1, 0, 4370 &cached_state); 4371 ordered = btrfs_lookup_ordered_range(inode, hole_start, 4372 block_end - hole_start); 4373 if (!ordered) 4374 break; 4375 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4376 &cached_state, GFP_NOFS); 4377 btrfs_start_ordered_extent(inode, ordered, 1); 4378 btrfs_put_ordered_extent(ordered); 4379 } 4380 4381 cur_offset = hole_start; 4382 while (1) { 4383 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 4384 block_end - cur_offset, 0); 4385 if (IS_ERR(em)) { 4386 err = PTR_ERR(em); 4387 em = NULL; 4388 break; 4389 } 4390 last_byte = min(extent_map_end(em), block_end); 4391 last_byte = ALIGN(last_byte , root->sectorsize); 4392 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4393 struct extent_map *hole_em; 4394 hole_size = last_byte - cur_offset; 4395 4396 err = maybe_insert_hole(root, inode, cur_offset, 4397 hole_size); 4398 if (err) 4399 break; 4400 btrfs_drop_extent_cache(inode, cur_offset, 4401 cur_offset + hole_size - 1, 0); 4402 hole_em = alloc_extent_map(); 4403 if (!hole_em) { 4404 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4405 &BTRFS_I(inode)->runtime_flags); 4406 goto next; 4407 } 4408 hole_em->start = cur_offset; 4409 hole_em->len = hole_size; 4410 hole_em->orig_start = cur_offset; 4411 4412 hole_em->block_start = EXTENT_MAP_HOLE; 4413 hole_em->block_len = 0; 4414 hole_em->orig_block_len = 0; 4415 hole_em->ram_bytes = hole_size; 4416 hole_em->bdev = root->fs_info->fs_devices->latest_bdev; 4417 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4418 hole_em->generation = root->fs_info->generation; 4419 4420 while (1) { 4421 write_lock(&em_tree->lock); 4422 err = add_extent_mapping(em_tree, hole_em, 1); 4423 write_unlock(&em_tree->lock); 4424 if (err != -EEXIST) 4425 break; 4426 btrfs_drop_extent_cache(inode, cur_offset, 4427 cur_offset + 4428 hole_size - 1, 0); 4429 } 4430 free_extent_map(hole_em); 4431 } 4432 next: 4433 free_extent_map(em); 4434 em = NULL; 4435 cur_offset = last_byte; 4436 if (cur_offset >= block_end) 4437 break; 4438 } 4439 free_extent_map(em); 4440 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4441 GFP_NOFS); 4442 return err; 4443 } 4444 4445 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4446 { 4447 struct btrfs_root *root = BTRFS_I(inode)->root; 4448 struct btrfs_trans_handle *trans; 4449 loff_t oldsize = i_size_read(inode); 4450 loff_t newsize = attr->ia_size; 4451 int mask = attr->ia_valid; 4452 int ret; 4453 4454 /* 4455 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4456 * special case where we need to update the times despite not having 4457 * these flags set. For all other operations the VFS set these flags 4458 * explicitly if it wants a timestamp update. 4459 */ 4460 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME)))) 4461 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb); 4462 4463 if (newsize > oldsize) { 4464 truncate_pagecache(inode, newsize); 4465 ret = btrfs_cont_expand(inode, oldsize, newsize); 4466 if (ret) 4467 return ret; 4468 4469 trans = btrfs_start_transaction(root, 1); 4470 if (IS_ERR(trans)) 4471 return PTR_ERR(trans); 4472 4473 i_size_write(inode, newsize); 4474 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4475 ret = btrfs_update_inode(trans, root, inode); 4476 btrfs_end_transaction(trans, root); 4477 } else { 4478 4479 /* 4480 * We're truncating a file that used to have good data down to 4481 * zero. Make sure it gets into the ordered flush list so that 4482 * any new writes get down to disk quickly. 4483 */ 4484 if (newsize == 0) 4485 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4486 &BTRFS_I(inode)->runtime_flags); 4487 4488 /* 4489 * 1 for the orphan item we're going to add 4490 * 1 for the orphan item deletion. 4491 */ 4492 trans = btrfs_start_transaction(root, 2); 4493 if (IS_ERR(trans)) 4494 return PTR_ERR(trans); 4495 4496 /* 4497 * We need to do this in case we fail at _any_ point during the 4498 * actual truncate. Once we do the truncate_setsize we could 4499 * invalidate pages which forces any outstanding ordered io to 4500 * be instantly completed which will give us extents that need 4501 * to be truncated. If we fail to get an orphan inode down we 4502 * could have left over extents that were never meant to live, 4503 * so we need to garuntee from this point on that everything 4504 * will be consistent. 4505 */ 4506 ret = btrfs_orphan_add(trans, inode); 4507 btrfs_end_transaction(trans, root); 4508 if (ret) 4509 return ret; 4510 4511 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4512 truncate_setsize(inode, newsize); 4513 4514 /* Disable nonlocked read DIO to avoid the end less truncate */ 4515 btrfs_inode_block_unlocked_dio(inode); 4516 inode_dio_wait(inode); 4517 btrfs_inode_resume_unlocked_dio(inode); 4518 4519 ret = btrfs_truncate(inode); 4520 if (ret && inode->i_nlink) { 4521 int err; 4522 4523 /* 4524 * failed to truncate, disk_i_size is only adjusted down 4525 * as we remove extents, so it should represent the true 4526 * size of the inode, so reset the in memory size and 4527 * delete our orphan entry. 4528 */ 4529 trans = btrfs_join_transaction(root); 4530 if (IS_ERR(trans)) { 4531 btrfs_orphan_del(NULL, inode); 4532 return ret; 4533 } 4534 i_size_write(inode, BTRFS_I(inode)->disk_i_size); 4535 err = btrfs_orphan_del(trans, inode); 4536 if (err) 4537 btrfs_abort_transaction(trans, root, err); 4538 btrfs_end_transaction(trans, root); 4539 } 4540 } 4541 4542 return ret; 4543 } 4544 4545 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 4546 { 4547 struct inode *inode = dentry->d_inode; 4548 struct btrfs_root *root = BTRFS_I(inode)->root; 4549 int err; 4550 4551 if (btrfs_root_readonly(root)) 4552 return -EROFS; 4553 4554 err = inode_change_ok(inode, attr); 4555 if (err) 4556 return err; 4557 4558 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 4559 err = btrfs_setsize(inode, attr); 4560 if (err) 4561 return err; 4562 } 4563 4564 if (attr->ia_valid) { 4565 setattr_copy(inode, attr); 4566 inode_inc_iversion(inode); 4567 err = btrfs_dirty_inode(inode); 4568 4569 if (!err && attr->ia_valid & ATTR_MODE) 4570 err = btrfs_acl_chmod(inode); 4571 } 4572 4573 return err; 4574 } 4575 4576 /* 4577 * While truncating the inode pages during eviction, we get the VFS calling 4578 * btrfs_invalidatepage() against each page of the inode. This is slow because 4579 * the calls to btrfs_invalidatepage() result in a huge amount of calls to 4580 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting 4581 * extent_state structures over and over, wasting lots of time. 4582 * 4583 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all 4584 * those expensive operations on a per page basis and do only the ordered io 4585 * finishing, while we release here the extent_map and extent_state structures, 4586 * without the excessive merging and splitting. 4587 */ 4588 static void evict_inode_truncate_pages(struct inode *inode) 4589 { 4590 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4591 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; 4592 struct rb_node *node; 4593 4594 ASSERT(inode->i_state & I_FREEING); 4595 truncate_inode_pages(&inode->i_data, 0); 4596 4597 write_lock(&map_tree->lock); 4598 while (!RB_EMPTY_ROOT(&map_tree->map)) { 4599 struct extent_map *em; 4600 4601 node = rb_first(&map_tree->map); 4602 em = rb_entry(node, struct extent_map, rb_node); 4603 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 4604 clear_bit(EXTENT_FLAG_LOGGING, &em->flags); 4605 remove_extent_mapping(map_tree, em); 4606 free_extent_map(em); 4607 } 4608 write_unlock(&map_tree->lock); 4609 4610 spin_lock(&io_tree->lock); 4611 while (!RB_EMPTY_ROOT(&io_tree->state)) { 4612 struct extent_state *state; 4613 struct extent_state *cached_state = NULL; 4614 4615 node = rb_first(&io_tree->state); 4616 state = rb_entry(node, struct extent_state, rb_node); 4617 atomic_inc(&state->refs); 4618 spin_unlock(&io_tree->lock); 4619 4620 lock_extent_bits(io_tree, state->start, state->end, 4621 0, &cached_state); 4622 clear_extent_bit(io_tree, state->start, state->end, 4623 EXTENT_LOCKED | EXTENT_DIRTY | 4624 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 4625 EXTENT_DEFRAG, 1, 1, 4626 &cached_state, GFP_NOFS); 4627 free_extent_state(state); 4628 4629 spin_lock(&io_tree->lock); 4630 } 4631 spin_unlock(&io_tree->lock); 4632 } 4633 4634 void btrfs_evict_inode(struct inode *inode) 4635 { 4636 struct btrfs_trans_handle *trans; 4637 struct btrfs_root *root = BTRFS_I(inode)->root; 4638 struct btrfs_block_rsv *rsv, *global_rsv; 4639 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 4640 int ret; 4641 4642 trace_btrfs_inode_evict(inode); 4643 4644 evict_inode_truncate_pages(inode); 4645 4646 if (inode->i_nlink && 4647 ((btrfs_root_refs(&root->root_item) != 0 && 4648 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || 4649 btrfs_is_free_space_inode(inode))) 4650 goto no_delete; 4651 4652 if (is_bad_inode(inode)) { 4653 btrfs_orphan_del(NULL, inode); 4654 goto no_delete; 4655 } 4656 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 4657 btrfs_wait_ordered_range(inode, 0, (u64)-1); 4658 4659 if (root->fs_info->log_root_recovering) { 4660 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 4661 &BTRFS_I(inode)->runtime_flags)); 4662 goto no_delete; 4663 } 4664 4665 if (inode->i_nlink > 0) { 4666 BUG_ON(btrfs_root_refs(&root->root_item) != 0 && 4667 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); 4668 goto no_delete; 4669 } 4670 4671 ret = btrfs_commit_inode_delayed_inode(inode); 4672 if (ret) { 4673 btrfs_orphan_del(NULL, inode); 4674 goto no_delete; 4675 } 4676 4677 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 4678 if (!rsv) { 4679 btrfs_orphan_del(NULL, inode); 4680 goto no_delete; 4681 } 4682 rsv->size = min_size; 4683 rsv->failfast = 1; 4684 global_rsv = &root->fs_info->global_block_rsv; 4685 4686 btrfs_i_size_write(inode, 0); 4687 4688 /* 4689 * This is a bit simpler than btrfs_truncate since we've already 4690 * reserved our space for our orphan item in the unlink, so we just 4691 * need to reserve some slack space in case we add bytes and update 4692 * inode item when doing the truncate. 4693 */ 4694 while (1) { 4695 ret = btrfs_block_rsv_refill(root, rsv, min_size, 4696 BTRFS_RESERVE_FLUSH_LIMIT); 4697 4698 /* 4699 * Try and steal from the global reserve since we will 4700 * likely not use this space anyway, we want to try as 4701 * hard as possible to get this to work. 4702 */ 4703 if (ret) 4704 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size); 4705 4706 if (ret) { 4707 btrfs_warn(root->fs_info, 4708 "Could not get space for a delete, will truncate on mount %d", 4709 ret); 4710 btrfs_orphan_del(NULL, inode); 4711 btrfs_free_block_rsv(root, rsv); 4712 goto no_delete; 4713 } 4714 4715 trans = btrfs_join_transaction(root); 4716 if (IS_ERR(trans)) { 4717 btrfs_orphan_del(NULL, inode); 4718 btrfs_free_block_rsv(root, rsv); 4719 goto no_delete; 4720 } 4721 4722 trans->block_rsv = rsv; 4723 4724 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 4725 if (ret != -ENOSPC) 4726 break; 4727 4728 trans->block_rsv = &root->fs_info->trans_block_rsv; 4729 btrfs_end_transaction(trans, root); 4730 trans = NULL; 4731 btrfs_btree_balance_dirty(root); 4732 } 4733 4734 btrfs_free_block_rsv(root, rsv); 4735 4736 /* 4737 * Errors here aren't a big deal, it just means we leave orphan items 4738 * in the tree. They will be cleaned up on the next mount. 4739 */ 4740 if (ret == 0) { 4741 trans->block_rsv = root->orphan_block_rsv; 4742 btrfs_orphan_del(trans, inode); 4743 } else { 4744 btrfs_orphan_del(NULL, inode); 4745 } 4746 4747 trans->block_rsv = &root->fs_info->trans_block_rsv; 4748 if (!(root == root->fs_info->tree_root || 4749 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 4750 btrfs_return_ino(root, btrfs_ino(inode)); 4751 4752 btrfs_end_transaction(trans, root); 4753 btrfs_btree_balance_dirty(root); 4754 no_delete: 4755 btrfs_remove_delayed_node(inode); 4756 clear_inode(inode); 4757 return; 4758 } 4759 4760 /* 4761 * this returns the key found in the dir entry in the location pointer. 4762 * If no dir entries were found, location->objectid is 0. 4763 */ 4764 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 4765 struct btrfs_key *location) 4766 { 4767 const char *name = dentry->d_name.name; 4768 int namelen = dentry->d_name.len; 4769 struct btrfs_dir_item *di; 4770 struct btrfs_path *path; 4771 struct btrfs_root *root = BTRFS_I(dir)->root; 4772 int ret = 0; 4773 4774 path = btrfs_alloc_path(); 4775 if (!path) 4776 return -ENOMEM; 4777 4778 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, 4779 namelen, 0); 4780 if (IS_ERR(di)) 4781 ret = PTR_ERR(di); 4782 4783 if (IS_ERR_OR_NULL(di)) 4784 goto out_err; 4785 4786 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 4787 out: 4788 btrfs_free_path(path); 4789 return ret; 4790 out_err: 4791 location->objectid = 0; 4792 goto out; 4793 } 4794 4795 /* 4796 * when we hit a tree root in a directory, the btrfs part of the inode 4797 * needs to be changed to reflect the root directory of the tree root. This 4798 * is kind of like crossing a mount point. 4799 */ 4800 static int fixup_tree_root_location(struct btrfs_root *root, 4801 struct inode *dir, 4802 struct dentry *dentry, 4803 struct btrfs_key *location, 4804 struct btrfs_root **sub_root) 4805 { 4806 struct btrfs_path *path; 4807 struct btrfs_root *new_root; 4808 struct btrfs_root_ref *ref; 4809 struct extent_buffer *leaf; 4810 int ret; 4811 int err = 0; 4812 4813 path = btrfs_alloc_path(); 4814 if (!path) { 4815 err = -ENOMEM; 4816 goto out; 4817 } 4818 4819 err = -ENOENT; 4820 ret = btrfs_find_item(root->fs_info->tree_root, path, 4821 BTRFS_I(dir)->root->root_key.objectid, 4822 location->objectid, BTRFS_ROOT_REF_KEY, NULL); 4823 if (ret) { 4824 if (ret < 0) 4825 err = ret; 4826 goto out; 4827 } 4828 4829 leaf = path->nodes[0]; 4830 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 4831 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || 4832 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 4833 goto out; 4834 4835 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 4836 (unsigned long)(ref + 1), 4837 dentry->d_name.len); 4838 if (ret) 4839 goto out; 4840 4841 btrfs_release_path(path); 4842 4843 new_root = btrfs_read_fs_root_no_name(root->fs_info, location); 4844 if (IS_ERR(new_root)) { 4845 err = PTR_ERR(new_root); 4846 goto out; 4847 } 4848 4849 *sub_root = new_root; 4850 location->objectid = btrfs_root_dirid(&new_root->root_item); 4851 location->type = BTRFS_INODE_ITEM_KEY; 4852 location->offset = 0; 4853 err = 0; 4854 out: 4855 btrfs_free_path(path); 4856 return err; 4857 } 4858 4859 static void inode_tree_add(struct inode *inode) 4860 { 4861 struct btrfs_root *root = BTRFS_I(inode)->root; 4862 struct btrfs_inode *entry; 4863 struct rb_node **p; 4864 struct rb_node *parent; 4865 struct rb_node *new = &BTRFS_I(inode)->rb_node; 4866 u64 ino = btrfs_ino(inode); 4867 4868 if (inode_unhashed(inode)) 4869 return; 4870 parent = NULL; 4871 spin_lock(&root->inode_lock); 4872 p = &root->inode_tree.rb_node; 4873 while (*p) { 4874 parent = *p; 4875 entry = rb_entry(parent, struct btrfs_inode, rb_node); 4876 4877 if (ino < btrfs_ino(&entry->vfs_inode)) 4878 p = &parent->rb_left; 4879 else if (ino > btrfs_ino(&entry->vfs_inode)) 4880 p = &parent->rb_right; 4881 else { 4882 WARN_ON(!(entry->vfs_inode.i_state & 4883 (I_WILL_FREE | I_FREEING))); 4884 rb_replace_node(parent, new, &root->inode_tree); 4885 RB_CLEAR_NODE(parent); 4886 spin_unlock(&root->inode_lock); 4887 return; 4888 } 4889 } 4890 rb_link_node(new, parent, p); 4891 rb_insert_color(new, &root->inode_tree); 4892 spin_unlock(&root->inode_lock); 4893 } 4894 4895 static void inode_tree_del(struct inode *inode) 4896 { 4897 struct btrfs_root *root = BTRFS_I(inode)->root; 4898 int empty = 0; 4899 4900 spin_lock(&root->inode_lock); 4901 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 4902 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 4903 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 4904 empty = RB_EMPTY_ROOT(&root->inode_tree); 4905 } 4906 spin_unlock(&root->inode_lock); 4907 4908 if (empty && btrfs_root_refs(&root->root_item) == 0) { 4909 synchronize_srcu(&root->fs_info->subvol_srcu); 4910 spin_lock(&root->inode_lock); 4911 empty = RB_EMPTY_ROOT(&root->inode_tree); 4912 spin_unlock(&root->inode_lock); 4913 if (empty) 4914 btrfs_add_dead_root(root); 4915 } 4916 } 4917 4918 void btrfs_invalidate_inodes(struct btrfs_root *root) 4919 { 4920 struct rb_node *node; 4921 struct rb_node *prev; 4922 struct btrfs_inode *entry; 4923 struct inode *inode; 4924 u64 objectid = 0; 4925 4926 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 4927 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 4928 4929 spin_lock(&root->inode_lock); 4930 again: 4931 node = root->inode_tree.rb_node; 4932 prev = NULL; 4933 while (node) { 4934 prev = node; 4935 entry = rb_entry(node, struct btrfs_inode, rb_node); 4936 4937 if (objectid < btrfs_ino(&entry->vfs_inode)) 4938 node = node->rb_left; 4939 else if (objectid > btrfs_ino(&entry->vfs_inode)) 4940 node = node->rb_right; 4941 else 4942 break; 4943 } 4944 if (!node) { 4945 while (prev) { 4946 entry = rb_entry(prev, struct btrfs_inode, rb_node); 4947 if (objectid <= btrfs_ino(&entry->vfs_inode)) { 4948 node = prev; 4949 break; 4950 } 4951 prev = rb_next(prev); 4952 } 4953 } 4954 while (node) { 4955 entry = rb_entry(node, struct btrfs_inode, rb_node); 4956 objectid = btrfs_ino(&entry->vfs_inode) + 1; 4957 inode = igrab(&entry->vfs_inode); 4958 if (inode) { 4959 spin_unlock(&root->inode_lock); 4960 if (atomic_read(&inode->i_count) > 1) 4961 d_prune_aliases(inode); 4962 /* 4963 * btrfs_drop_inode will have it removed from 4964 * the inode cache when its usage count 4965 * hits zero. 4966 */ 4967 iput(inode); 4968 cond_resched(); 4969 spin_lock(&root->inode_lock); 4970 goto again; 4971 } 4972 4973 if (cond_resched_lock(&root->inode_lock)) 4974 goto again; 4975 4976 node = rb_next(node); 4977 } 4978 spin_unlock(&root->inode_lock); 4979 } 4980 4981 static int btrfs_init_locked_inode(struct inode *inode, void *p) 4982 { 4983 struct btrfs_iget_args *args = p; 4984 inode->i_ino = args->location->objectid; 4985 memcpy(&BTRFS_I(inode)->location, args->location, 4986 sizeof(*args->location)); 4987 BTRFS_I(inode)->root = args->root; 4988 return 0; 4989 } 4990 4991 static int btrfs_find_actor(struct inode *inode, void *opaque) 4992 { 4993 struct btrfs_iget_args *args = opaque; 4994 return args->location->objectid == BTRFS_I(inode)->location.objectid && 4995 args->root == BTRFS_I(inode)->root; 4996 } 4997 4998 static struct inode *btrfs_iget_locked(struct super_block *s, 4999 struct btrfs_key *location, 5000 struct btrfs_root *root) 5001 { 5002 struct inode *inode; 5003 struct btrfs_iget_args args; 5004 unsigned long hashval = btrfs_inode_hash(location->objectid, root); 5005 5006 args.location = location; 5007 args.root = root; 5008 5009 inode = iget5_locked(s, hashval, btrfs_find_actor, 5010 btrfs_init_locked_inode, 5011 (void *)&args); 5012 return inode; 5013 } 5014 5015 /* Get an inode object given its location and corresponding root. 5016 * Returns in *is_new if the inode was read from disk 5017 */ 5018 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 5019 struct btrfs_root *root, int *new) 5020 { 5021 struct inode *inode; 5022 5023 inode = btrfs_iget_locked(s, location, root); 5024 if (!inode) 5025 return ERR_PTR(-ENOMEM); 5026 5027 if (inode->i_state & I_NEW) { 5028 btrfs_read_locked_inode(inode); 5029 if (!is_bad_inode(inode)) { 5030 inode_tree_add(inode); 5031 unlock_new_inode(inode); 5032 if (new) 5033 *new = 1; 5034 } else { 5035 unlock_new_inode(inode); 5036 iput(inode); 5037 inode = ERR_PTR(-ESTALE); 5038 } 5039 } 5040 5041 return inode; 5042 } 5043 5044 static struct inode *new_simple_dir(struct super_block *s, 5045 struct btrfs_key *key, 5046 struct btrfs_root *root) 5047 { 5048 struct inode *inode = new_inode(s); 5049 5050 if (!inode) 5051 return ERR_PTR(-ENOMEM); 5052 5053 BTRFS_I(inode)->root = root; 5054 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 5055 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 5056 5057 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 5058 inode->i_op = &btrfs_dir_ro_inode_operations; 5059 inode->i_fop = &simple_dir_operations; 5060 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 5061 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5062 5063 return inode; 5064 } 5065 5066 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 5067 { 5068 struct inode *inode; 5069 struct btrfs_root *root = BTRFS_I(dir)->root; 5070 struct btrfs_root *sub_root = root; 5071 struct btrfs_key location; 5072 int index; 5073 int ret = 0; 5074 5075 if (dentry->d_name.len > BTRFS_NAME_LEN) 5076 return ERR_PTR(-ENAMETOOLONG); 5077 5078 ret = btrfs_inode_by_name(dir, dentry, &location); 5079 if (ret < 0) 5080 return ERR_PTR(ret); 5081 5082 if (location.objectid == 0) 5083 return ERR_PTR(-ENOENT); 5084 5085 if (location.type == BTRFS_INODE_ITEM_KEY) { 5086 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 5087 return inode; 5088 } 5089 5090 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 5091 5092 index = srcu_read_lock(&root->fs_info->subvol_srcu); 5093 ret = fixup_tree_root_location(root, dir, dentry, 5094 &location, &sub_root); 5095 if (ret < 0) { 5096 if (ret != -ENOENT) 5097 inode = ERR_PTR(ret); 5098 else 5099 inode = new_simple_dir(dir->i_sb, &location, sub_root); 5100 } else { 5101 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 5102 } 5103 srcu_read_unlock(&root->fs_info->subvol_srcu, index); 5104 5105 if (!IS_ERR(inode) && root != sub_root) { 5106 down_read(&root->fs_info->cleanup_work_sem); 5107 if (!(inode->i_sb->s_flags & MS_RDONLY)) 5108 ret = btrfs_orphan_cleanup(sub_root); 5109 up_read(&root->fs_info->cleanup_work_sem); 5110 if (ret) { 5111 iput(inode); 5112 inode = ERR_PTR(ret); 5113 } 5114 } 5115 5116 return inode; 5117 } 5118 5119 static int btrfs_dentry_delete(const struct dentry *dentry) 5120 { 5121 struct btrfs_root *root; 5122 struct inode *inode = dentry->d_inode; 5123 5124 if (!inode && !IS_ROOT(dentry)) 5125 inode = dentry->d_parent->d_inode; 5126 5127 if (inode) { 5128 root = BTRFS_I(inode)->root; 5129 if (btrfs_root_refs(&root->root_item) == 0) 5130 return 1; 5131 5132 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 5133 return 1; 5134 } 5135 return 0; 5136 } 5137 5138 static void btrfs_dentry_release(struct dentry *dentry) 5139 { 5140 if (dentry->d_fsdata) 5141 kfree(dentry->d_fsdata); 5142 } 5143 5144 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5145 unsigned int flags) 5146 { 5147 struct inode *inode; 5148 5149 inode = btrfs_lookup_dentry(dir, dentry); 5150 if (IS_ERR(inode)) { 5151 if (PTR_ERR(inode) == -ENOENT) 5152 inode = NULL; 5153 else 5154 return ERR_CAST(inode); 5155 } 5156 5157 return d_materialise_unique(dentry, inode); 5158 } 5159 5160 unsigned char btrfs_filetype_table[] = { 5161 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5162 }; 5163 5164 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) 5165 { 5166 struct inode *inode = file_inode(file); 5167 struct btrfs_root *root = BTRFS_I(inode)->root; 5168 struct btrfs_item *item; 5169 struct btrfs_dir_item *di; 5170 struct btrfs_key key; 5171 struct btrfs_key found_key; 5172 struct btrfs_path *path; 5173 struct list_head ins_list; 5174 struct list_head del_list; 5175 int ret; 5176 struct extent_buffer *leaf; 5177 int slot; 5178 unsigned char d_type; 5179 int over = 0; 5180 u32 di_cur; 5181 u32 di_total; 5182 u32 di_len; 5183 int key_type = BTRFS_DIR_INDEX_KEY; 5184 char tmp_name[32]; 5185 char *name_ptr; 5186 int name_len; 5187 int is_curr = 0; /* ctx->pos points to the current index? */ 5188 5189 /* FIXME, use a real flag for deciding about the key type */ 5190 if (root->fs_info->tree_root == root) 5191 key_type = BTRFS_DIR_ITEM_KEY; 5192 5193 if (!dir_emit_dots(file, ctx)) 5194 return 0; 5195 5196 path = btrfs_alloc_path(); 5197 if (!path) 5198 return -ENOMEM; 5199 5200 path->reada = 1; 5201 5202 if (key_type == BTRFS_DIR_INDEX_KEY) { 5203 INIT_LIST_HEAD(&ins_list); 5204 INIT_LIST_HEAD(&del_list); 5205 btrfs_get_delayed_items(inode, &ins_list, &del_list); 5206 } 5207 5208 btrfs_set_key_type(&key, key_type); 5209 key.offset = ctx->pos; 5210 key.objectid = btrfs_ino(inode); 5211 5212 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5213 if (ret < 0) 5214 goto err; 5215 5216 while (1) { 5217 leaf = path->nodes[0]; 5218 slot = path->slots[0]; 5219 if (slot >= btrfs_header_nritems(leaf)) { 5220 ret = btrfs_next_leaf(root, path); 5221 if (ret < 0) 5222 goto err; 5223 else if (ret > 0) 5224 break; 5225 continue; 5226 } 5227 5228 item = btrfs_item_nr(slot); 5229 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5230 5231 if (found_key.objectid != key.objectid) 5232 break; 5233 if (btrfs_key_type(&found_key) != key_type) 5234 break; 5235 if (found_key.offset < ctx->pos) 5236 goto next; 5237 if (key_type == BTRFS_DIR_INDEX_KEY && 5238 btrfs_should_delete_dir_index(&del_list, 5239 found_key.offset)) 5240 goto next; 5241 5242 ctx->pos = found_key.offset; 5243 is_curr = 1; 5244 5245 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5246 di_cur = 0; 5247 di_total = btrfs_item_size(leaf, item); 5248 5249 while (di_cur < di_total) { 5250 struct btrfs_key location; 5251 5252 if (verify_dir_item(root, leaf, di)) 5253 break; 5254 5255 name_len = btrfs_dir_name_len(leaf, di); 5256 if (name_len <= sizeof(tmp_name)) { 5257 name_ptr = tmp_name; 5258 } else { 5259 name_ptr = kmalloc(name_len, GFP_NOFS); 5260 if (!name_ptr) { 5261 ret = -ENOMEM; 5262 goto err; 5263 } 5264 } 5265 read_extent_buffer(leaf, name_ptr, 5266 (unsigned long)(di + 1), name_len); 5267 5268 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5269 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5270 5271 5272 /* is this a reference to our own snapshot? If so 5273 * skip it. 5274 * 5275 * In contrast to old kernels, we insert the snapshot's 5276 * dir item and dir index after it has been created, so 5277 * we won't find a reference to our own snapshot. We 5278 * still keep the following code for backward 5279 * compatibility. 5280 */ 5281 if (location.type == BTRFS_ROOT_ITEM_KEY && 5282 location.objectid == root->root_key.objectid) { 5283 over = 0; 5284 goto skip; 5285 } 5286 over = !dir_emit(ctx, name_ptr, name_len, 5287 location.objectid, d_type); 5288 5289 skip: 5290 if (name_ptr != tmp_name) 5291 kfree(name_ptr); 5292 5293 if (over) 5294 goto nopos; 5295 di_len = btrfs_dir_name_len(leaf, di) + 5296 btrfs_dir_data_len(leaf, di) + sizeof(*di); 5297 di_cur += di_len; 5298 di = (struct btrfs_dir_item *)((char *)di + di_len); 5299 } 5300 next: 5301 path->slots[0]++; 5302 } 5303 5304 if (key_type == BTRFS_DIR_INDEX_KEY) { 5305 if (is_curr) 5306 ctx->pos++; 5307 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); 5308 if (ret) 5309 goto nopos; 5310 } 5311 5312 /* Reached end of directory/root. Bump pos past the last item. */ 5313 ctx->pos++; 5314 5315 /* 5316 * Stop new entries from being returned after we return the last 5317 * entry. 5318 * 5319 * New directory entries are assigned a strictly increasing 5320 * offset. This means that new entries created during readdir 5321 * are *guaranteed* to be seen in the future by that readdir. 5322 * This has broken buggy programs which operate on names as 5323 * they're returned by readdir. Until we re-use freed offsets 5324 * we have this hack to stop new entries from being returned 5325 * under the assumption that they'll never reach this huge 5326 * offset. 5327 * 5328 * This is being careful not to overflow 32bit loff_t unless the 5329 * last entry requires it because doing so has broken 32bit apps 5330 * in the past. 5331 */ 5332 if (key_type == BTRFS_DIR_INDEX_KEY) { 5333 if (ctx->pos >= INT_MAX) 5334 ctx->pos = LLONG_MAX; 5335 else 5336 ctx->pos = INT_MAX; 5337 } 5338 nopos: 5339 ret = 0; 5340 err: 5341 if (key_type == BTRFS_DIR_INDEX_KEY) 5342 btrfs_put_delayed_items(&ins_list, &del_list); 5343 btrfs_free_path(path); 5344 return ret; 5345 } 5346 5347 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5348 { 5349 struct btrfs_root *root = BTRFS_I(inode)->root; 5350 struct btrfs_trans_handle *trans; 5351 int ret = 0; 5352 bool nolock = false; 5353 5354 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5355 return 0; 5356 5357 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) 5358 nolock = true; 5359 5360 if (wbc->sync_mode == WB_SYNC_ALL) { 5361 if (nolock) 5362 trans = btrfs_join_transaction_nolock(root); 5363 else 5364 trans = btrfs_join_transaction(root); 5365 if (IS_ERR(trans)) 5366 return PTR_ERR(trans); 5367 ret = btrfs_commit_transaction(trans, root); 5368 } 5369 return ret; 5370 } 5371 5372 /* 5373 * This is somewhat expensive, updating the tree every time the 5374 * inode changes. But, it is most likely to find the inode in cache. 5375 * FIXME, needs more benchmarking...there are no reasons other than performance 5376 * to keep or drop this code. 5377 */ 5378 static int btrfs_dirty_inode(struct inode *inode) 5379 { 5380 struct btrfs_root *root = BTRFS_I(inode)->root; 5381 struct btrfs_trans_handle *trans; 5382 int ret; 5383 5384 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5385 return 0; 5386 5387 trans = btrfs_join_transaction(root); 5388 if (IS_ERR(trans)) 5389 return PTR_ERR(trans); 5390 5391 ret = btrfs_update_inode(trans, root, inode); 5392 if (ret && ret == -ENOSPC) { 5393 /* whoops, lets try again with the full transaction */ 5394 btrfs_end_transaction(trans, root); 5395 trans = btrfs_start_transaction(root, 1); 5396 if (IS_ERR(trans)) 5397 return PTR_ERR(trans); 5398 5399 ret = btrfs_update_inode(trans, root, inode); 5400 } 5401 btrfs_end_transaction(trans, root); 5402 if (BTRFS_I(inode)->delayed_node) 5403 btrfs_balance_delayed_items(root); 5404 5405 return ret; 5406 } 5407 5408 /* 5409 * This is a copy of file_update_time. We need this so we can return error on 5410 * ENOSPC for updating the inode in the case of file write and mmap writes. 5411 */ 5412 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5413 int flags) 5414 { 5415 struct btrfs_root *root = BTRFS_I(inode)->root; 5416 5417 if (btrfs_root_readonly(root)) 5418 return -EROFS; 5419 5420 if (flags & S_VERSION) 5421 inode_inc_iversion(inode); 5422 if (flags & S_CTIME) 5423 inode->i_ctime = *now; 5424 if (flags & S_MTIME) 5425 inode->i_mtime = *now; 5426 if (flags & S_ATIME) 5427 inode->i_atime = *now; 5428 return btrfs_dirty_inode(inode); 5429 } 5430 5431 /* 5432 * find the highest existing sequence number in a directory 5433 * and then set the in-memory index_cnt variable to reflect 5434 * free sequence numbers 5435 */ 5436 static int btrfs_set_inode_index_count(struct inode *inode) 5437 { 5438 struct btrfs_root *root = BTRFS_I(inode)->root; 5439 struct btrfs_key key, found_key; 5440 struct btrfs_path *path; 5441 struct extent_buffer *leaf; 5442 int ret; 5443 5444 key.objectid = btrfs_ino(inode); 5445 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); 5446 key.offset = (u64)-1; 5447 5448 path = btrfs_alloc_path(); 5449 if (!path) 5450 return -ENOMEM; 5451 5452 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5453 if (ret < 0) 5454 goto out; 5455 /* FIXME: we should be able to handle this */ 5456 if (ret == 0) 5457 goto out; 5458 ret = 0; 5459 5460 /* 5461 * MAGIC NUMBER EXPLANATION: 5462 * since we search a directory based on f_pos we have to start at 2 5463 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 5464 * else has to start at 2 5465 */ 5466 if (path->slots[0] == 0) { 5467 BTRFS_I(inode)->index_cnt = 2; 5468 goto out; 5469 } 5470 5471 path->slots[0]--; 5472 5473 leaf = path->nodes[0]; 5474 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5475 5476 if (found_key.objectid != btrfs_ino(inode) || 5477 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) { 5478 BTRFS_I(inode)->index_cnt = 2; 5479 goto out; 5480 } 5481 5482 BTRFS_I(inode)->index_cnt = found_key.offset + 1; 5483 out: 5484 btrfs_free_path(path); 5485 return ret; 5486 } 5487 5488 /* 5489 * helper to find a free sequence number in a given directory. This current 5490 * code is very simple, later versions will do smarter things in the btree 5491 */ 5492 int btrfs_set_inode_index(struct inode *dir, u64 *index) 5493 { 5494 int ret = 0; 5495 5496 if (BTRFS_I(dir)->index_cnt == (u64)-1) { 5497 ret = btrfs_inode_delayed_dir_index_count(dir); 5498 if (ret) { 5499 ret = btrfs_set_inode_index_count(dir); 5500 if (ret) 5501 return ret; 5502 } 5503 } 5504 5505 *index = BTRFS_I(dir)->index_cnt; 5506 BTRFS_I(dir)->index_cnt++; 5507 5508 return ret; 5509 } 5510 5511 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 5512 struct btrfs_root *root, 5513 struct inode *dir, 5514 const char *name, int name_len, 5515 u64 ref_objectid, u64 objectid, 5516 umode_t mode, u64 *index) 5517 { 5518 struct inode *inode; 5519 struct btrfs_inode_item *inode_item; 5520 struct btrfs_key *location; 5521 struct btrfs_path *path; 5522 struct btrfs_inode_ref *ref; 5523 struct btrfs_key key[2]; 5524 u32 sizes[2]; 5525 unsigned long ptr; 5526 int ret; 5527 5528 path = btrfs_alloc_path(); 5529 if (!path) 5530 return ERR_PTR(-ENOMEM); 5531 5532 inode = new_inode(root->fs_info->sb); 5533 if (!inode) { 5534 btrfs_free_path(path); 5535 return ERR_PTR(-ENOMEM); 5536 } 5537 5538 /* 5539 * we have to initialize this early, so we can reclaim the inode 5540 * number if we fail afterwards in this function. 5541 */ 5542 inode->i_ino = objectid; 5543 5544 if (dir) { 5545 trace_btrfs_inode_request(dir); 5546 5547 ret = btrfs_set_inode_index(dir, index); 5548 if (ret) { 5549 btrfs_free_path(path); 5550 iput(inode); 5551 return ERR_PTR(ret); 5552 } 5553 } 5554 /* 5555 * index_cnt is ignored for everything but a dir, 5556 * btrfs_get_inode_index_count has an explanation for the magic 5557 * number 5558 */ 5559 BTRFS_I(inode)->index_cnt = 2; 5560 BTRFS_I(inode)->dir_index = *index; 5561 BTRFS_I(inode)->root = root; 5562 BTRFS_I(inode)->generation = trans->transid; 5563 inode->i_generation = BTRFS_I(inode)->generation; 5564 5565 /* 5566 * We could have gotten an inode number from somebody who was fsynced 5567 * and then removed in this same transaction, so let's just set full 5568 * sync since it will be a full sync anyway and this will blow away the 5569 * old info in the log. 5570 */ 5571 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 5572 5573 key[0].objectid = objectid; 5574 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY); 5575 key[0].offset = 0; 5576 5577 /* 5578 * Start new inodes with an inode_ref. This is slightly more 5579 * efficient for small numbers of hard links since they will 5580 * be packed into one item. Extended refs will kick in if we 5581 * add more hard links than can fit in the ref item. 5582 */ 5583 key[1].objectid = objectid; 5584 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); 5585 key[1].offset = ref_objectid; 5586 5587 sizes[0] = sizeof(struct btrfs_inode_item); 5588 sizes[1] = name_len + sizeof(*ref); 5589 5590 path->leave_spinning = 1; 5591 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2); 5592 if (ret != 0) 5593 goto fail; 5594 5595 inode_init_owner(inode, dir, mode); 5596 inode_set_bytes(inode, 0); 5597 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5598 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 5599 struct btrfs_inode_item); 5600 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, 5601 sizeof(*inode_item)); 5602 fill_inode_item(trans, path->nodes[0], inode_item, inode); 5603 5604 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 5605 struct btrfs_inode_ref); 5606 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 5607 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 5608 ptr = (unsigned long)(ref + 1); 5609 write_extent_buffer(path->nodes[0], name, ptr, name_len); 5610 5611 btrfs_mark_buffer_dirty(path->nodes[0]); 5612 btrfs_free_path(path); 5613 5614 location = &BTRFS_I(inode)->location; 5615 location->objectid = objectid; 5616 location->offset = 0; 5617 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); 5618 5619 btrfs_inherit_iflags(inode, dir); 5620 5621 if (S_ISREG(mode)) { 5622 if (btrfs_test_opt(root, NODATASUM)) 5623 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 5624 if (btrfs_test_opt(root, NODATACOW)) 5625 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 5626 BTRFS_INODE_NODATASUM; 5627 } 5628 5629 btrfs_insert_inode_hash(inode); 5630 inode_tree_add(inode); 5631 5632 trace_btrfs_inode_new(inode); 5633 btrfs_set_inode_last_trans(trans, inode); 5634 5635 btrfs_update_root_times(trans, root); 5636 5637 ret = btrfs_inode_inherit_props(trans, inode, dir); 5638 if (ret) 5639 btrfs_err(root->fs_info, 5640 "error inheriting props for ino %llu (root %llu): %d", 5641 btrfs_ino(inode), root->root_key.objectid, ret); 5642 5643 return inode; 5644 fail: 5645 if (dir) 5646 BTRFS_I(dir)->index_cnt--; 5647 btrfs_free_path(path); 5648 iput(inode); 5649 return ERR_PTR(ret); 5650 } 5651 5652 static inline u8 btrfs_inode_type(struct inode *inode) 5653 { 5654 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 5655 } 5656 5657 /* 5658 * utility function to add 'inode' into 'parent_inode' with 5659 * a give name and a given sequence number. 5660 * if 'add_backref' is true, also insert a backref from the 5661 * inode to the parent directory. 5662 */ 5663 int btrfs_add_link(struct btrfs_trans_handle *trans, 5664 struct inode *parent_inode, struct inode *inode, 5665 const char *name, int name_len, int add_backref, u64 index) 5666 { 5667 int ret = 0; 5668 struct btrfs_key key; 5669 struct btrfs_root *root = BTRFS_I(parent_inode)->root; 5670 u64 ino = btrfs_ino(inode); 5671 u64 parent_ino = btrfs_ino(parent_inode); 5672 5673 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5674 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); 5675 } else { 5676 key.objectid = ino; 5677 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); 5678 key.offset = 0; 5679 } 5680 5681 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5682 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 5683 key.objectid, root->root_key.objectid, 5684 parent_ino, index, name, name_len); 5685 } else if (add_backref) { 5686 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 5687 parent_ino, index); 5688 } 5689 5690 /* Nothing to clean up yet */ 5691 if (ret) 5692 return ret; 5693 5694 ret = btrfs_insert_dir_item(trans, root, name, name_len, 5695 parent_inode, &key, 5696 btrfs_inode_type(inode), index); 5697 if (ret == -EEXIST || ret == -EOVERFLOW) 5698 goto fail_dir_item; 5699 else if (ret) { 5700 btrfs_abort_transaction(trans, root, ret); 5701 return ret; 5702 } 5703 5704 btrfs_i_size_write(parent_inode, parent_inode->i_size + 5705 name_len * 2); 5706 inode_inc_iversion(parent_inode); 5707 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 5708 ret = btrfs_update_inode(trans, root, parent_inode); 5709 if (ret) 5710 btrfs_abort_transaction(trans, root, ret); 5711 return ret; 5712 5713 fail_dir_item: 5714 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5715 u64 local_index; 5716 int err; 5717 err = btrfs_del_root_ref(trans, root->fs_info->tree_root, 5718 key.objectid, root->root_key.objectid, 5719 parent_ino, &local_index, name, name_len); 5720 5721 } else if (add_backref) { 5722 u64 local_index; 5723 int err; 5724 5725 err = btrfs_del_inode_ref(trans, root, name, name_len, 5726 ino, parent_ino, &local_index); 5727 } 5728 return ret; 5729 } 5730 5731 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 5732 struct inode *dir, struct dentry *dentry, 5733 struct inode *inode, int backref, u64 index) 5734 { 5735 int err = btrfs_add_link(trans, dir, inode, 5736 dentry->d_name.name, dentry->d_name.len, 5737 backref, index); 5738 if (err > 0) 5739 err = -EEXIST; 5740 return err; 5741 } 5742 5743 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 5744 umode_t mode, dev_t rdev) 5745 { 5746 struct btrfs_trans_handle *trans; 5747 struct btrfs_root *root = BTRFS_I(dir)->root; 5748 struct inode *inode = NULL; 5749 int err; 5750 int drop_inode = 0; 5751 u64 objectid; 5752 u64 index = 0; 5753 5754 if (!new_valid_dev(rdev)) 5755 return -EINVAL; 5756 5757 /* 5758 * 2 for inode item and ref 5759 * 2 for dir items 5760 * 1 for xattr if selinux is on 5761 */ 5762 trans = btrfs_start_transaction(root, 5); 5763 if (IS_ERR(trans)) 5764 return PTR_ERR(trans); 5765 5766 err = btrfs_find_free_ino(root, &objectid); 5767 if (err) 5768 goto out_unlock; 5769 5770 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5771 dentry->d_name.len, btrfs_ino(dir), objectid, 5772 mode, &index); 5773 if (IS_ERR(inode)) { 5774 err = PTR_ERR(inode); 5775 goto out_unlock; 5776 } 5777 5778 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5779 if (err) { 5780 drop_inode = 1; 5781 goto out_unlock; 5782 } 5783 5784 /* 5785 * If the active LSM wants to access the inode during 5786 * d_instantiate it needs these. Smack checks to see 5787 * if the filesystem supports xattrs by looking at the 5788 * ops vector. 5789 */ 5790 5791 inode->i_op = &btrfs_special_inode_operations; 5792 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5793 if (err) 5794 drop_inode = 1; 5795 else { 5796 init_special_inode(inode, inode->i_mode, rdev); 5797 btrfs_update_inode(trans, root, inode); 5798 d_instantiate(dentry, inode); 5799 } 5800 out_unlock: 5801 btrfs_end_transaction(trans, root); 5802 btrfs_balance_delayed_items(root); 5803 btrfs_btree_balance_dirty(root); 5804 if (drop_inode) { 5805 inode_dec_link_count(inode); 5806 iput(inode); 5807 } 5808 return err; 5809 } 5810 5811 static int btrfs_create(struct inode *dir, struct dentry *dentry, 5812 umode_t mode, bool excl) 5813 { 5814 struct btrfs_trans_handle *trans; 5815 struct btrfs_root *root = BTRFS_I(dir)->root; 5816 struct inode *inode = NULL; 5817 int drop_inode_on_err = 0; 5818 int err; 5819 u64 objectid; 5820 u64 index = 0; 5821 5822 /* 5823 * 2 for inode item and ref 5824 * 2 for dir items 5825 * 1 for xattr if selinux is on 5826 */ 5827 trans = btrfs_start_transaction(root, 5); 5828 if (IS_ERR(trans)) 5829 return PTR_ERR(trans); 5830 5831 err = btrfs_find_free_ino(root, &objectid); 5832 if (err) 5833 goto out_unlock; 5834 5835 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5836 dentry->d_name.len, btrfs_ino(dir), objectid, 5837 mode, &index); 5838 if (IS_ERR(inode)) { 5839 err = PTR_ERR(inode); 5840 goto out_unlock; 5841 } 5842 drop_inode_on_err = 1; 5843 5844 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5845 if (err) 5846 goto out_unlock; 5847 5848 err = btrfs_update_inode(trans, root, inode); 5849 if (err) 5850 goto out_unlock; 5851 5852 /* 5853 * If the active LSM wants to access the inode during 5854 * d_instantiate it needs these. Smack checks to see 5855 * if the filesystem supports xattrs by looking at the 5856 * ops vector. 5857 */ 5858 inode->i_fop = &btrfs_file_operations; 5859 inode->i_op = &btrfs_file_inode_operations; 5860 5861 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5862 if (err) 5863 goto out_unlock; 5864 5865 inode->i_mapping->a_ops = &btrfs_aops; 5866 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 5867 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 5868 d_instantiate(dentry, inode); 5869 5870 out_unlock: 5871 btrfs_end_transaction(trans, root); 5872 if (err && drop_inode_on_err) { 5873 inode_dec_link_count(inode); 5874 iput(inode); 5875 } 5876 btrfs_balance_delayed_items(root); 5877 btrfs_btree_balance_dirty(root); 5878 return err; 5879 } 5880 5881 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 5882 struct dentry *dentry) 5883 { 5884 struct btrfs_trans_handle *trans; 5885 struct btrfs_root *root = BTRFS_I(dir)->root; 5886 struct inode *inode = old_dentry->d_inode; 5887 u64 index; 5888 int err; 5889 int drop_inode = 0; 5890 5891 /* do not allow sys_link's with other subvols of the same device */ 5892 if (root->objectid != BTRFS_I(inode)->root->objectid) 5893 return -EXDEV; 5894 5895 if (inode->i_nlink >= BTRFS_LINK_MAX) 5896 return -EMLINK; 5897 5898 err = btrfs_set_inode_index(dir, &index); 5899 if (err) 5900 goto fail; 5901 5902 /* 5903 * 2 items for inode and inode ref 5904 * 2 items for dir items 5905 * 1 item for parent inode 5906 */ 5907 trans = btrfs_start_transaction(root, 5); 5908 if (IS_ERR(trans)) { 5909 err = PTR_ERR(trans); 5910 goto fail; 5911 } 5912 5913 /* There are several dir indexes for this inode, clear the cache. */ 5914 BTRFS_I(inode)->dir_index = 0ULL; 5915 inc_nlink(inode); 5916 inode_inc_iversion(inode); 5917 inode->i_ctime = CURRENT_TIME; 5918 ihold(inode); 5919 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 5920 5921 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); 5922 5923 if (err) { 5924 drop_inode = 1; 5925 } else { 5926 struct dentry *parent = dentry->d_parent; 5927 err = btrfs_update_inode(trans, root, inode); 5928 if (err) 5929 goto fail; 5930 d_instantiate(dentry, inode); 5931 btrfs_log_new_name(trans, inode, NULL, parent); 5932 } 5933 5934 btrfs_end_transaction(trans, root); 5935 btrfs_balance_delayed_items(root); 5936 fail: 5937 if (drop_inode) { 5938 inode_dec_link_count(inode); 5939 iput(inode); 5940 } 5941 btrfs_btree_balance_dirty(root); 5942 return err; 5943 } 5944 5945 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 5946 { 5947 struct inode *inode = NULL; 5948 struct btrfs_trans_handle *trans; 5949 struct btrfs_root *root = BTRFS_I(dir)->root; 5950 int err = 0; 5951 int drop_on_err = 0; 5952 u64 objectid = 0; 5953 u64 index = 0; 5954 5955 /* 5956 * 2 items for inode and ref 5957 * 2 items for dir items 5958 * 1 for xattr if selinux is on 5959 */ 5960 trans = btrfs_start_transaction(root, 5); 5961 if (IS_ERR(trans)) 5962 return PTR_ERR(trans); 5963 5964 err = btrfs_find_free_ino(root, &objectid); 5965 if (err) 5966 goto out_fail; 5967 5968 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5969 dentry->d_name.len, btrfs_ino(dir), objectid, 5970 S_IFDIR | mode, &index); 5971 if (IS_ERR(inode)) { 5972 err = PTR_ERR(inode); 5973 goto out_fail; 5974 } 5975 5976 drop_on_err = 1; 5977 5978 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5979 if (err) 5980 goto out_fail; 5981 5982 inode->i_op = &btrfs_dir_inode_operations; 5983 inode->i_fop = &btrfs_dir_file_operations; 5984 5985 btrfs_i_size_write(inode, 0); 5986 err = btrfs_update_inode(trans, root, inode); 5987 if (err) 5988 goto out_fail; 5989 5990 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, 5991 dentry->d_name.len, 0, index); 5992 if (err) 5993 goto out_fail; 5994 5995 d_instantiate(dentry, inode); 5996 drop_on_err = 0; 5997 5998 out_fail: 5999 btrfs_end_transaction(trans, root); 6000 if (drop_on_err) 6001 iput(inode); 6002 btrfs_balance_delayed_items(root); 6003 btrfs_btree_balance_dirty(root); 6004 return err; 6005 } 6006 6007 /* helper for btfs_get_extent. Given an existing extent in the tree, 6008 * and an extent that you want to insert, deal with overlap and insert 6009 * the new extent into the tree. 6010 */ 6011 static int merge_extent_mapping(struct extent_map_tree *em_tree, 6012 struct extent_map *existing, 6013 struct extent_map *em, 6014 u64 map_start, u64 map_len) 6015 { 6016 u64 start_diff; 6017 6018 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 6019 start_diff = map_start - em->start; 6020 em->start = map_start; 6021 em->len = map_len; 6022 if (em->block_start < EXTENT_MAP_LAST_BYTE && 6023 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 6024 em->block_start += start_diff; 6025 em->block_len -= start_diff; 6026 } 6027 return add_extent_mapping(em_tree, em, 0); 6028 } 6029 6030 static noinline int uncompress_inline(struct btrfs_path *path, 6031 struct inode *inode, struct page *page, 6032 size_t pg_offset, u64 extent_offset, 6033 struct btrfs_file_extent_item *item) 6034 { 6035 int ret; 6036 struct extent_buffer *leaf = path->nodes[0]; 6037 char *tmp; 6038 size_t max_size; 6039 unsigned long inline_size; 6040 unsigned long ptr; 6041 int compress_type; 6042 6043 WARN_ON(pg_offset != 0); 6044 compress_type = btrfs_file_extent_compression(leaf, item); 6045 max_size = btrfs_file_extent_ram_bytes(leaf, item); 6046 inline_size = btrfs_file_extent_inline_item_len(leaf, 6047 btrfs_item_nr(path->slots[0])); 6048 tmp = kmalloc(inline_size, GFP_NOFS); 6049 if (!tmp) 6050 return -ENOMEM; 6051 ptr = btrfs_file_extent_inline_start(item); 6052 6053 read_extent_buffer(leaf, tmp, ptr, inline_size); 6054 6055 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); 6056 ret = btrfs_decompress(compress_type, tmp, page, 6057 extent_offset, inline_size, max_size); 6058 if (ret) { 6059 char *kaddr = kmap_atomic(page); 6060 unsigned long copy_size = min_t(u64, 6061 PAGE_CACHE_SIZE - pg_offset, 6062 max_size - extent_offset); 6063 memset(kaddr + pg_offset, 0, copy_size); 6064 kunmap_atomic(kaddr); 6065 } 6066 kfree(tmp); 6067 return 0; 6068 } 6069 6070 /* 6071 * a bit scary, this does extent mapping from logical file offset to the disk. 6072 * the ugly parts come from merging extents from the disk with the in-ram 6073 * representation. This gets more complex because of the data=ordered code, 6074 * where the in-ram extents might be locked pending data=ordered completion. 6075 * 6076 * This also copies inline extents directly into the page. 6077 */ 6078 6079 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 6080 size_t pg_offset, u64 start, u64 len, 6081 int create) 6082 { 6083 int ret; 6084 int err = 0; 6085 u64 bytenr; 6086 u64 extent_start = 0; 6087 u64 extent_end = 0; 6088 u64 objectid = btrfs_ino(inode); 6089 u32 found_type; 6090 struct btrfs_path *path = NULL; 6091 struct btrfs_root *root = BTRFS_I(inode)->root; 6092 struct btrfs_file_extent_item *item; 6093 struct extent_buffer *leaf; 6094 struct btrfs_key found_key; 6095 struct extent_map *em = NULL; 6096 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 6097 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 6098 struct btrfs_trans_handle *trans = NULL; 6099 int compress_type; 6100 6101 again: 6102 read_lock(&em_tree->lock); 6103 em = lookup_extent_mapping(em_tree, start, len); 6104 if (em) 6105 em->bdev = root->fs_info->fs_devices->latest_bdev; 6106 read_unlock(&em_tree->lock); 6107 6108 if (em) { 6109 if (em->start > start || em->start + em->len <= start) 6110 free_extent_map(em); 6111 else if (em->block_start == EXTENT_MAP_INLINE && page) 6112 free_extent_map(em); 6113 else 6114 goto out; 6115 } 6116 em = alloc_extent_map(); 6117 if (!em) { 6118 err = -ENOMEM; 6119 goto out; 6120 } 6121 em->bdev = root->fs_info->fs_devices->latest_bdev; 6122 em->start = EXTENT_MAP_HOLE; 6123 em->orig_start = EXTENT_MAP_HOLE; 6124 em->len = (u64)-1; 6125 em->block_len = (u64)-1; 6126 6127 if (!path) { 6128 path = btrfs_alloc_path(); 6129 if (!path) { 6130 err = -ENOMEM; 6131 goto out; 6132 } 6133 /* 6134 * Chances are we'll be called again, so go ahead and do 6135 * readahead 6136 */ 6137 path->reada = 1; 6138 } 6139 6140 ret = btrfs_lookup_file_extent(trans, root, path, 6141 objectid, start, trans != NULL); 6142 if (ret < 0) { 6143 err = ret; 6144 goto out; 6145 } 6146 6147 if (ret != 0) { 6148 if (path->slots[0] == 0) 6149 goto not_found; 6150 path->slots[0]--; 6151 } 6152 6153 leaf = path->nodes[0]; 6154 item = btrfs_item_ptr(leaf, path->slots[0], 6155 struct btrfs_file_extent_item); 6156 /* are we inside the extent that was found? */ 6157 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6158 found_type = btrfs_key_type(&found_key); 6159 if (found_key.objectid != objectid || 6160 found_type != BTRFS_EXTENT_DATA_KEY) { 6161 /* 6162 * If we backup past the first extent we want to move forward 6163 * and see if there is an extent in front of us, otherwise we'll 6164 * say there is a hole for our whole search range which can 6165 * cause problems. 6166 */ 6167 extent_end = start; 6168 goto next; 6169 } 6170 6171 found_type = btrfs_file_extent_type(leaf, item); 6172 extent_start = found_key.offset; 6173 compress_type = btrfs_file_extent_compression(leaf, item); 6174 if (found_type == BTRFS_FILE_EXTENT_REG || 6175 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6176 extent_end = extent_start + 6177 btrfs_file_extent_num_bytes(leaf, item); 6178 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6179 size_t size; 6180 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6181 extent_end = ALIGN(extent_start + size, root->sectorsize); 6182 } 6183 next: 6184 if (start >= extent_end) { 6185 path->slots[0]++; 6186 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6187 ret = btrfs_next_leaf(root, path); 6188 if (ret < 0) { 6189 err = ret; 6190 goto out; 6191 } 6192 if (ret > 0) 6193 goto not_found; 6194 leaf = path->nodes[0]; 6195 } 6196 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6197 if (found_key.objectid != objectid || 6198 found_key.type != BTRFS_EXTENT_DATA_KEY) 6199 goto not_found; 6200 if (start + len <= found_key.offset) 6201 goto not_found; 6202 em->start = start; 6203 em->orig_start = start; 6204 em->len = found_key.offset - start; 6205 goto not_found_em; 6206 } 6207 6208 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item); 6209 if (found_type == BTRFS_FILE_EXTENT_REG || 6210 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6211 em->start = extent_start; 6212 em->len = extent_end - extent_start; 6213 em->orig_start = extent_start - 6214 btrfs_file_extent_offset(leaf, item); 6215 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, 6216 item); 6217 bytenr = btrfs_file_extent_disk_bytenr(leaf, item); 6218 if (bytenr == 0) { 6219 em->block_start = EXTENT_MAP_HOLE; 6220 goto insert; 6221 } 6222 if (compress_type != BTRFS_COMPRESS_NONE) { 6223 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6224 em->compress_type = compress_type; 6225 em->block_start = bytenr; 6226 em->block_len = em->orig_block_len; 6227 } else { 6228 bytenr += btrfs_file_extent_offset(leaf, item); 6229 em->block_start = bytenr; 6230 em->block_len = em->len; 6231 if (found_type == BTRFS_FILE_EXTENT_PREALLOC) 6232 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6233 } 6234 goto insert; 6235 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6236 unsigned long ptr; 6237 char *map; 6238 size_t size; 6239 size_t extent_offset; 6240 size_t copy_size; 6241 6242 em->block_start = EXTENT_MAP_INLINE; 6243 if (!page || create) { 6244 em->start = extent_start; 6245 em->len = extent_end - extent_start; 6246 goto out; 6247 } 6248 6249 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6250 extent_offset = page_offset(page) + pg_offset - extent_start; 6251 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, 6252 size - extent_offset); 6253 em->start = extent_start + extent_offset; 6254 em->len = ALIGN(copy_size, root->sectorsize); 6255 em->orig_block_len = em->len; 6256 em->orig_start = em->start; 6257 if (compress_type) { 6258 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6259 em->compress_type = compress_type; 6260 } 6261 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6262 if (create == 0 && !PageUptodate(page)) { 6263 if (btrfs_file_extent_compression(leaf, item) != 6264 BTRFS_COMPRESS_NONE) { 6265 ret = uncompress_inline(path, inode, page, 6266 pg_offset, 6267 extent_offset, item); 6268 BUG_ON(ret); /* -ENOMEM */ 6269 } else { 6270 map = kmap(page); 6271 read_extent_buffer(leaf, map + pg_offset, ptr, 6272 copy_size); 6273 if (pg_offset + copy_size < PAGE_CACHE_SIZE) { 6274 memset(map + pg_offset + copy_size, 0, 6275 PAGE_CACHE_SIZE - pg_offset - 6276 copy_size); 6277 } 6278 kunmap(page); 6279 } 6280 flush_dcache_page(page); 6281 } else if (create && PageUptodate(page)) { 6282 BUG(); 6283 if (!trans) { 6284 kunmap(page); 6285 free_extent_map(em); 6286 em = NULL; 6287 6288 btrfs_release_path(path); 6289 trans = btrfs_join_transaction(root); 6290 6291 if (IS_ERR(trans)) 6292 return ERR_CAST(trans); 6293 goto again; 6294 } 6295 map = kmap(page); 6296 write_extent_buffer(leaf, map + pg_offset, ptr, 6297 copy_size); 6298 kunmap(page); 6299 btrfs_mark_buffer_dirty(leaf); 6300 } 6301 set_extent_uptodate(io_tree, em->start, 6302 extent_map_end(em) - 1, NULL, GFP_NOFS); 6303 goto insert; 6304 } else { 6305 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type); 6306 } 6307 not_found: 6308 em->start = start; 6309 em->orig_start = start; 6310 em->len = len; 6311 not_found_em: 6312 em->block_start = EXTENT_MAP_HOLE; 6313 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6314 insert: 6315 btrfs_release_path(path); 6316 if (em->start > start || extent_map_end(em) <= start) { 6317 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", 6318 em->start, em->len, start, len); 6319 err = -EIO; 6320 goto out; 6321 } 6322 6323 err = 0; 6324 write_lock(&em_tree->lock); 6325 ret = add_extent_mapping(em_tree, em, 0); 6326 /* it is possible that someone inserted the extent into the tree 6327 * while we had the lock dropped. It is also possible that 6328 * an overlapping map exists in the tree 6329 */ 6330 if (ret == -EEXIST) { 6331 struct extent_map *existing; 6332 6333 ret = 0; 6334 6335 existing = lookup_extent_mapping(em_tree, start, len); 6336 if (existing && (existing->start > start || 6337 existing->start + existing->len <= start)) { 6338 free_extent_map(existing); 6339 existing = NULL; 6340 } 6341 if (!existing) { 6342 existing = lookup_extent_mapping(em_tree, em->start, 6343 em->len); 6344 if (existing) { 6345 err = merge_extent_mapping(em_tree, existing, 6346 em, start, 6347 root->sectorsize); 6348 free_extent_map(existing); 6349 if (err) { 6350 free_extent_map(em); 6351 em = NULL; 6352 } 6353 } else { 6354 err = -EIO; 6355 free_extent_map(em); 6356 em = NULL; 6357 } 6358 } else { 6359 free_extent_map(em); 6360 em = existing; 6361 err = 0; 6362 } 6363 } 6364 write_unlock(&em_tree->lock); 6365 out: 6366 6367 trace_btrfs_get_extent(root, em); 6368 6369 if (path) 6370 btrfs_free_path(path); 6371 if (trans) { 6372 ret = btrfs_end_transaction(trans, root); 6373 if (!err) 6374 err = ret; 6375 } 6376 if (err) { 6377 free_extent_map(em); 6378 return ERR_PTR(err); 6379 } 6380 BUG_ON(!em); /* Error is always set */ 6381 return em; 6382 } 6383 6384 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, 6385 size_t pg_offset, u64 start, u64 len, 6386 int create) 6387 { 6388 struct extent_map *em; 6389 struct extent_map *hole_em = NULL; 6390 u64 range_start = start; 6391 u64 end; 6392 u64 found; 6393 u64 found_end; 6394 int err = 0; 6395 6396 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 6397 if (IS_ERR(em)) 6398 return em; 6399 if (em) { 6400 /* 6401 * if our em maps to 6402 * - a hole or 6403 * - a pre-alloc extent, 6404 * there might actually be delalloc bytes behind it. 6405 */ 6406 if (em->block_start != EXTENT_MAP_HOLE && 6407 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6408 return em; 6409 else 6410 hole_em = em; 6411 } 6412 6413 /* check to see if we've wrapped (len == -1 or similar) */ 6414 end = start + len; 6415 if (end < start) 6416 end = (u64)-1; 6417 else 6418 end -= 1; 6419 6420 em = NULL; 6421 6422 /* ok, we didn't find anything, lets look for delalloc */ 6423 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, 6424 end, len, EXTENT_DELALLOC, 1); 6425 found_end = range_start + found; 6426 if (found_end < range_start) 6427 found_end = (u64)-1; 6428 6429 /* 6430 * we didn't find anything useful, return 6431 * the original results from get_extent() 6432 */ 6433 if (range_start > end || found_end <= start) { 6434 em = hole_em; 6435 hole_em = NULL; 6436 goto out; 6437 } 6438 6439 /* adjust the range_start to make sure it doesn't 6440 * go backwards from the start they passed in 6441 */ 6442 range_start = max(start, range_start); 6443 found = found_end - range_start; 6444 6445 if (found > 0) { 6446 u64 hole_start = start; 6447 u64 hole_len = len; 6448 6449 em = alloc_extent_map(); 6450 if (!em) { 6451 err = -ENOMEM; 6452 goto out; 6453 } 6454 /* 6455 * when btrfs_get_extent can't find anything it 6456 * returns one huge hole 6457 * 6458 * make sure what it found really fits our range, and 6459 * adjust to make sure it is based on the start from 6460 * the caller 6461 */ 6462 if (hole_em) { 6463 u64 calc_end = extent_map_end(hole_em); 6464 6465 if (calc_end <= start || (hole_em->start > end)) { 6466 free_extent_map(hole_em); 6467 hole_em = NULL; 6468 } else { 6469 hole_start = max(hole_em->start, start); 6470 hole_len = calc_end - hole_start; 6471 } 6472 } 6473 em->bdev = NULL; 6474 if (hole_em && range_start > hole_start) { 6475 /* our hole starts before our delalloc, so we 6476 * have to return just the parts of the hole 6477 * that go until the delalloc starts 6478 */ 6479 em->len = min(hole_len, 6480 range_start - hole_start); 6481 em->start = hole_start; 6482 em->orig_start = hole_start; 6483 /* 6484 * don't adjust block start at all, 6485 * it is fixed at EXTENT_MAP_HOLE 6486 */ 6487 em->block_start = hole_em->block_start; 6488 em->block_len = hole_len; 6489 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 6490 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6491 } else { 6492 em->start = range_start; 6493 em->len = found; 6494 em->orig_start = range_start; 6495 em->block_start = EXTENT_MAP_DELALLOC; 6496 em->block_len = found; 6497 } 6498 } else if (hole_em) { 6499 return hole_em; 6500 } 6501 out: 6502 6503 free_extent_map(hole_em); 6504 if (err) { 6505 free_extent_map(em); 6506 return ERR_PTR(err); 6507 } 6508 return em; 6509 } 6510 6511 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 6512 u64 start, u64 len) 6513 { 6514 struct btrfs_root *root = BTRFS_I(inode)->root; 6515 struct extent_map *em; 6516 struct btrfs_key ins; 6517 u64 alloc_hint; 6518 int ret; 6519 6520 alloc_hint = get_extent_allocation_hint(inode, start, len); 6521 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0, 6522 alloc_hint, &ins, 1); 6523 if (ret) 6524 return ERR_PTR(ret); 6525 6526 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, 6527 ins.offset, ins.offset, ins.offset, 0); 6528 if (IS_ERR(em)) { 6529 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 6530 return em; 6531 } 6532 6533 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, 6534 ins.offset, ins.offset, 0); 6535 if (ret) { 6536 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 6537 free_extent_map(em); 6538 return ERR_PTR(ret); 6539 } 6540 6541 return em; 6542 } 6543 6544 /* 6545 * returns 1 when the nocow is safe, < 1 on error, 0 if the 6546 * block must be cow'd 6547 */ 6548 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, 6549 u64 *orig_start, u64 *orig_block_len, 6550 u64 *ram_bytes) 6551 { 6552 struct btrfs_trans_handle *trans; 6553 struct btrfs_path *path; 6554 int ret; 6555 struct extent_buffer *leaf; 6556 struct btrfs_root *root = BTRFS_I(inode)->root; 6557 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 6558 struct btrfs_file_extent_item *fi; 6559 struct btrfs_key key; 6560 u64 disk_bytenr; 6561 u64 backref_offset; 6562 u64 extent_end; 6563 u64 num_bytes; 6564 int slot; 6565 int found_type; 6566 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); 6567 6568 path = btrfs_alloc_path(); 6569 if (!path) 6570 return -ENOMEM; 6571 6572 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), 6573 offset, 0); 6574 if (ret < 0) 6575 goto out; 6576 6577 slot = path->slots[0]; 6578 if (ret == 1) { 6579 if (slot == 0) { 6580 /* can't find the item, must cow */ 6581 ret = 0; 6582 goto out; 6583 } 6584 slot--; 6585 } 6586 ret = 0; 6587 leaf = path->nodes[0]; 6588 btrfs_item_key_to_cpu(leaf, &key, slot); 6589 if (key.objectid != btrfs_ino(inode) || 6590 key.type != BTRFS_EXTENT_DATA_KEY) { 6591 /* not our file or wrong item type, must cow */ 6592 goto out; 6593 } 6594 6595 if (key.offset > offset) { 6596 /* Wrong offset, must cow */ 6597 goto out; 6598 } 6599 6600 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 6601 found_type = btrfs_file_extent_type(leaf, fi); 6602 if (found_type != BTRFS_FILE_EXTENT_REG && 6603 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 6604 /* not a regular extent, must cow */ 6605 goto out; 6606 } 6607 6608 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) 6609 goto out; 6610 6611 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 6612 if (extent_end <= offset) 6613 goto out; 6614 6615 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 6616 if (disk_bytenr == 0) 6617 goto out; 6618 6619 if (btrfs_file_extent_compression(leaf, fi) || 6620 btrfs_file_extent_encryption(leaf, fi) || 6621 btrfs_file_extent_other_encoding(leaf, fi)) 6622 goto out; 6623 6624 backref_offset = btrfs_file_extent_offset(leaf, fi); 6625 6626 if (orig_start) { 6627 *orig_start = key.offset - backref_offset; 6628 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 6629 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 6630 } 6631 6632 if (btrfs_extent_readonly(root, disk_bytenr)) 6633 goto out; 6634 6635 num_bytes = min(offset + *len, extent_end) - offset; 6636 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6637 u64 range_end; 6638 6639 range_end = round_up(offset + num_bytes, root->sectorsize) - 1; 6640 ret = test_range_bit(io_tree, offset, range_end, 6641 EXTENT_DELALLOC, 0, NULL); 6642 if (ret) { 6643 ret = -EAGAIN; 6644 goto out; 6645 } 6646 } 6647 6648 btrfs_release_path(path); 6649 6650 /* 6651 * look for other files referencing this extent, if we 6652 * find any we must cow 6653 */ 6654 trans = btrfs_join_transaction(root); 6655 if (IS_ERR(trans)) { 6656 ret = 0; 6657 goto out; 6658 } 6659 6660 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), 6661 key.offset - backref_offset, disk_bytenr); 6662 btrfs_end_transaction(trans, root); 6663 if (ret) { 6664 ret = 0; 6665 goto out; 6666 } 6667 6668 /* 6669 * adjust disk_bytenr and num_bytes to cover just the bytes 6670 * in this extent we are about to write. If there 6671 * are any csums in that range we have to cow in order 6672 * to keep the csums correct 6673 */ 6674 disk_bytenr += backref_offset; 6675 disk_bytenr += offset - key.offset; 6676 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 6677 goto out; 6678 /* 6679 * all of the above have passed, it is safe to overwrite this extent 6680 * without cow 6681 */ 6682 *len = num_bytes; 6683 ret = 1; 6684 out: 6685 btrfs_free_path(path); 6686 return ret; 6687 } 6688 6689 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 6690 struct extent_state **cached_state, int writing) 6691 { 6692 struct btrfs_ordered_extent *ordered; 6693 int ret = 0; 6694 6695 while (1) { 6696 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6697 0, cached_state); 6698 /* 6699 * We're concerned with the entire range that we're going to be 6700 * doing DIO to, so we need to make sure theres no ordered 6701 * extents in this range. 6702 */ 6703 ordered = btrfs_lookup_ordered_range(inode, lockstart, 6704 lockend - lockstart + 1); 6705 6706 /* 6707 * We need to make sure there are no buffered pages in this 6708 * range either, we could have raced between the invalidate in 6709 * generic_file_direct_write and locking the extent. The 6710 * invalidate needs to happen so that reads after a write do not 6711 * get stale data. 6712 */ 6713 if (!ordered && (!writing || 6714 !test_range_bit(&BTRFS_I(inode)->io_tree, 6715 lockstart, lockend, EXTENT_UPTODATE, 0, 6716 *cached_state))) 6717 break; 6718 6719 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6720 cached_state, GFP_NOFS); 6721 6722 if (ordered) { 6723 btrfs_start_ordered_extent(inode, ordered, 1); 6724 btrfs_put_ordered_extent(ordered); 6725 } else { 6726 /* Screw you mmap */ 6727 ret = filemap_write_and_wait_range(inode->i_mapping, 6728 lockstart, 6729 lockend); 6730 if (ret) 6731 break; 6732 6733 /* 6734 * If we found a page that couldn't be invalidated just 6735 * fall back to buffered. 6736 */ 6737 ret = invalidate_inode_pages2_range(inode->i_mapping, 6738 lockstart >> PAGE_CACHE_SHIFT, 6739 lockend >> PAGE_CACHE_SHIFT); 6740 if (ret) 6741 break; 6742 } 6743 6744 cond_resched(); 6745 } 6746 6747 return ret; 6748 } 6749 6750 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 6751 u64 len, u64 orig_start, 6752 u64 block_start, u64 block_len, 6753 u64 orig_block_len, u64 ram_bytes, 6754 int type) 6755 { 6756 struct extent_map_tree *em_tree; 6757 struct extent_map *em; 6758 struct btrfs_root *root = BTRFS_I(inode)->root; 6759 int ret; 6760 6761 em_tree = &BTRFS_I(inode)->extent_tree; 6762 em = alloc_extent_map(); 6763 if (!em) 6764 return ERR_PTR(-ENOMEM); 6765 6766 em->start = start; 6767 em->orig_start = orig_start; 6768 em->mod_start = start; 6769 em->mod_len = len; 6770 em->len = len; 6771 em->block_len = block_len; 6772 em->block_start = block_start; 6773 em->bdev = root->fs_info->fs_devices->latest_bdev; 6774 em->orig_block_len = orig_block_len; 6775 em->ram_bytes = ram_bytes; 6776 em->generation = -1; 6777 set_bit(EXTENT_FLAG_PINNED, &em->flags); 6778 if (type == BTRFS_ORDERED_PREALLOC) 6779 set_bit(EXTENT_FLAG_FILLING, &em->flags); 6780 6781 do { 6782 btrfs_drop_extent_cache(inode, em->start, 6783 em->start + em->len - 1, 0); 6784 write_lock(&em_tree->lock); 6785 ret = add_extent_mapping(em_tree, em, 1); 6786 write_unlock(&em_tree->lock); 6787 } while (ret == -EEXIST); 6788 6789 if (ret) { 6790 free_extent_map(em); 6791 return ERR_PTR(ret); 6792 } 6793 6794 return em; 6795 } 6796 6797 6798 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 6799 struct buffer_head *bh_result, int create) 6800 { 6801 struct extent_map *em; 6802 struct btrfs_root *root = BTRFS_I(inode)->root; 6803 struct extent_state *cached_state = NULL; 6804 u64 start = iblock << inode->i_blkbits; 6805 u64 lockstart, lockend; 6806 u64 len = bh_result->b_size; 6807 int unlock_bits = EXTENT_LOCKED; 6808 int ret = 0; 6809 6810 if (create) 6811 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY; 6812 else 6813 len = min_t(u64, len, root->sectorsize); 6814 6815 lockstart = start; 6816 lockend = start + len - 1; 6817 6818 /* 6819 * If this errors out it's because we couldn't invalidate pagecache for 6820 * this range and we need to fallback to buffered. 6821 */ 6822 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) 6823 return -ENOTBLK; 6824 6825 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 6826 if (IS_ERR(em)) { 6827 ret = PTR_ERR(em); 6828 goto unlock_err; 6829 } 6830 6831 /* 6832 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 6833 * io. INLINE is special, and we could probably kludge it in here, but 6834 * it's still buffered so for safety lets just fall back to the generic 6835 * buffered path. 6836 * 6837 * For COMPRESSED we _have_ to read the entire extent in so we can 6838 * decompress it, so there will be buffering required no matter what we 6839 * do, so go ahead and fallback to buffered. 6840 * 6841 * We return -ENOTBLK because thats what makes DIO go ahead and go back 6842 * to buffered IO. Don't blame me, this is the price we pay for using 6843 * the generic code. 6844 */ 6845 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 6846 em->block_start == EXTENT_MAP_INLINE) { 6847 free_extent_map(em); 6848 ret = -ENOTBLK; 6849 goto unlock_err; 6850 } 6851 6852 /* Just a good old fashioned hole, return */ 6853 if (!create && (em->block_start == EXTENT_MAP_HOLE || 6854 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 6855 free_extent_map(em); 6856 goto unlock_err; 6857 } 6858 6859 /* 6860 * We don't allocate a new extent in the following cases 6861 * 6862 * 1) The inode is marked as NODATACOW. In this case we'll just use the 6863 * existing extent. 6864 * 2) The extent is marked as PREALLOC. We're good to go here and can 6865 * just use the extent. 6866 * 6867 */ 6868 if (!create) { 6869 len = min(len, em->len - (start - em->start)); 6870 lockstart = start + len; 6871 goto unlock; 6872 } 6873 6874 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 6875 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 6876 em->block_start != EXTENT_MAP_HOLE)) { 6877 int type; 6878 int ret; 6879 u64 block_start, orig_start, orig_block_len, ram_bytes; 6880 6881 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6882 type = BTRFS_ORDERED_PREALLOC; 6883 else 6884 type = BTRFS_ORDERED_NOCOW; 6885 len = min(len, em->len - (start - em->start)); 6886 block_start = em->block_start + (start - em->start); 6887 6888 if (can_nocow_extent(inode, start, &len, &orig_start, 6889 &orig_block_len, &ram_bytes) == 1) { 6890 if (type == BTRFS_ORDERED_PREALLOC) { 6891 free_extent_map(em); 6892 em = create_pinned_em(inode, start, len, 6893 orig_start, 6894 block_start, len, 6895 orig_block_len, 6896 ram_bytes, type); 6897 if (IS_ERR(em)) 6898 goto unlock_err; 6899 } 6900 6901 ret = btrfs_add_ordered_extent_dio(inode, start, 6902 block_start, len, len, type); 6903 if (ret) { 6904 free_extent_map(em); 6905 goto unlock_err; 6906 } 6907 goto unlock; 6908 } 6909 } 6910 6911 /* 6912 * this will cow the extent, reset the len in case we changed 6913 * it above 6914 */ 6915 len = bh_result->b_size; 6916 free_extent_map(em); 6917 em = btrfs_new_extent_direct(inode, start, len); 6918 if (IS_ERR(em)) { 6919 ret = PTR_ERR(em); 6920 goto unlock_err; 6921 } 6922 len = min(len, em->len - (start - em->start)); 6923 unlock: 6924 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 6925 inode->i_blkbits; 6926 bh_result->b_size = len; 6927 bh_result->b_bdev = em->bdev; 6928 set_buffer_mapped(bh_result); 6929 if (create) { 6930 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6931 set_buffer_new(bh_result); 6932 6933 /* 6934 * Need to update the i_size under the extent lock so buffered 6935 * readers will get the updated i_size when we unlock. 6936 */ 6937 if (start + len > i_size_read(inode)) 6938 i_size_write(inode, start + len); 6939 6940 spin_lock(&BTRFS_I(inode)->lock); 6941 BTRFS_I(inode)->outstanding_extents++; 6942 spin_unlock(&BTRFS_I(inode)->lock); 6943 6944 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6945 lockstart + len - 1, EXTENT_DELALLOC, NULL, 6946 &cached_state, GFP_NOFS); 6947 BUG_ON(ret); 6948 } 6949 6950 /* 6951 * In the case of write we need to clear and unlock the entire range, 6952 * in the case of read we need to unlock only the end area that we 6953 * aren't using if there is any left over space. 6954 */ 6955 if (lockstart < lockend) { 6956 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6957 lockend, unlock_bits, 1, 0, 6958 &cached_state, GFP_NOFS); 6959 } else { 6960 free_extent_state(cached_state); 6961 } 6962 6963 free_extent_map(em); 6964 6965 return 0; 6966 6967 unlock_err: 6968 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6969 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 6970 return ret; 6971 } 6972 6973 static void btrfs_endio_direct_read(struct bio *bio, int err) 6974 { 6975 struct btrfs_dio_private *dip = bio->bi_private; 6976 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1; 6977 struct bio_vec *bvec = bio->bi_io_vec; 6978 struct inode *inode = dip->inode; 6979 struct btrfs_root *root = BTRFS_I(inode)->root; 6980 struct bio *dio_bio; 6981 u32 *csums = (u32 *)dip->csum; 6982 int index = 0; 6983 u64 start; 6984 6985 start = dip->logical_offset; 6986 do { 6987 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { 6988 struct page *page = bvec->bv_page; 6989 char *kaddr; 6990 u32 csum = ~(u32)0; 6991 unsigned long flags; 6992 6993 local_irq_save(flags); 6994 kaddr = kmap_atomic(page); 6995 csum = btrfs_csum_data(kaddr + bvec->bv_offset, 6996 csum, bvec->bv_len); 6997 btrfs_csum_final(csum, (char *)&csum); 6998 kunmap_atomic(kaddr); 6999 local_irq_restore(flags); 7000 7001 flush_dcache_page(bvec->bv_page); 7002 if (csum != csums[index]) { 7003 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u", 7004 btrfs_ino(inode), start, csum, 7005 csums[index]); 7006 err = -EIO; 7007 } 7008 } 7009 7010 start += bvec->bv_len; 7011 bvec++; 7012 index++; 7013 } while (bvec <= bvec_end); 7014 7015 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 7016 dip->logical_offset + dip->bytes - 1); 7017 dio_bio = dip->dio_bio; 7018 7019 kfree(dip); 7020 7021 /* If we had a csum failure make sure to clear the uptodate flag */ 7022 if (err) 7023 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7024 dio_end_io(dio_bio, err); 7025 bio_put(bio); 7026 } 7027 7028 static void btrfs_endio_direct_write(struct bio *bio, int err) 7029 { 7030 struct btrfs_dio_private *dip = bio->bi_private; 7031 struct inode *inode = dip->inode; 7032 struct btrfs_root *root = BTRFS_I(inode)->root; 7033 struct btrfs_ordered_extent *ordered = NULL; 7034 u64 ordered_offset = dip->logical_offset; 7035 u64 ordered_bytes = dip->bytes; 7036 struct bio *dio_bio; 7037 int ret; 7038 7039 if (err) 7040 goto out_done; 7041 again: 7042 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 7043 &ordered_offset, 7044 ordered_bytes, !err); 7045 if (!ret) 7046 goto out_test; 7047 7048 btrfs_init_work(&ordered->work, finish_ordered_fn, NULL, NULL); 7049 btrfs_queue_work(root->fs_info->endio_write_workers, 7050 &ordered->work); 7051 out_test: 7052 /* 7053 * our bio might span multiple ordered extents. If we haven't 7054 * completed the accounting for the whole dio, go back and try again 7055 */ 7056 if (ordered_offset < dip->logical_offset + dip->bytes) { 7057 ordered_bytes = dip->logical_offset + dip->bytes - 7058 ordered_offset; 7059 ordered = NULL; 7060 goto again; 7061 } 7062 out_done: 7063 dio_bio = dip->dio_bio; 7064 7065 kfree(dip); 7066 7067 /* If we had an error make sure to clear the uptodate flag */ 7068 if (err) 7069 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7070 dio_end_io(dio_bio, err); 7071 bio_put(bio); 7072 } 7073 7074 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, 7075 struct bio *bio, int mirror_num, 7076 unsigned long bio_flags, u64 offset) 7077 { 7078 int ret; 7079 struct btrfs_root *root = BTRFS_I(inode)->root; 7080 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); 7081 BUG_ON(ret); /* -ENOMEM */ 7082 return 0; 7083 } 7084 7085 static void btrfs_end_dio_bio(struct bio *bio, int err) 7086 { 7087 struct btrfs_dio_private *dip = bio->bi_private; 7088 7089 if (err) { 7090 btrfs_err(BTRFS_I(dip->inode)->root->fs_info, 7091 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d", 7092 btrfs_ino(dip->inode), bio->bi_rw, 7093 (unsigned long long)bio->bi_sector, bio->bi_size, err); 7094 dip->errors = 1; 7095 7096 /* 7097 * before atomic variable goto zero, we must make sure 7098 * dip->errors is perceived to be set. 7099 */ 7100 smp_mb__before_atomic_dec(); 7101 } 7102 7103 /* if there are more bios still pending for this dio, just exit */ 7104 if (!atomic_dec_and_test(&dip->pending_bios)) 7105 goto out; 7106 7107 if (dip->errors) { 7108 bio_io_error(dip->orig_bio); 7109 } else { 7110 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags); 7111 bio_endio(dip->orig_bio, 0); 7112 } 7113 out: 7114 bio_put(bio); 7115 } 7116 7117 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 7118 u64 first_sector, gfp_t gfp_flags) 7119 { 7120 int nr_vecs = bio_get_nr_vecs(bdev); 7121 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); 7122 } 7123 7124 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 7125 int rw, u64 file_offset, int skip_sum, 7126 int async_submit) 7127 { 7128 struct btrfs_dio_private *dip = bio->bi_private; 7129 int write = rw & REQ_WRITE; 7130 struct btrfs_root *root = BTRFS_I(inode)->root; 7131 int ret; 7132 7133 if (async_submit) 7134 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 7135 7136 bio_get(bio); 7137 7138 if (!write) { 7139 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); 7140 if (ret) 7141 goto err; 7142 } 7143 7144 if (skip_sum) 7145 goto map; 7146 7147 if (write && async_submit) { 7148 ret = btrfs_wq_submit_bio(root->fs_info, 7149 inode, rw, bio, 0, 0, 7150 file_offset, 7151 __btrfs_submit_bio_start_direct_io, 7152 __btrfs_submit_bio_done); 7153 goto err; 7154 } else if (write) { 7155 /* 7156 * If we aren't doing async submit, calculate the csum of the 7157 * bio now. 7158 */ 7159 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); 7160 if (ret) 7161 goto err; 7162 } else if (!skip_sum) { 7163 ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio, 7164 file_offset); 7165 if (ret) 7166 goto err; 7167 } 7168 7169 map: 7170 ret = btrfs_map_bio(root, rw, bio, 0, async_submit); 7171 err: 7172 bio_put(bio); 7173 return ret; 7174 } 7175 7176 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, 7177 int skip_sum) 7178 { 7179 struct inode *inode = dip->inode; 7180 struct btrfs_root *root = BTRFS_I(inode)->root; 7181 struct bio *bio; 7182 struct bio *orig_bio = dip->orig_bio; 7183 struct bio_vec *bvec = orig_bio->bi_io_vec; 7184 u64 start_sector = orig_bio->bi_sector; 7185 u64 file_offset = dip->logical_offset; 7186 u64 submit_len = 0; 7187 u64 map_length; 7188 int nr_pages = 0; 7189 int ret = 0; 7190 int async_submit = 0; 7191 7192 map_length = orig_bio->bi_size; 7193 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, 7194 &map_length, NULL, 0); 7195 if (ret) { 7196 bio_put(orig_bio); 7197 return -EIO; 7198 } 7199 7200 if (map_length >= orig_bio->bi_size) { 7201 bio = orig_bio; 7202 goto submit; 7203 } 7204 7205 /* async crcs make it difficult to collect full stripe writes. */ 7206 if (btrfs_get_alloc_profile(root, 1) & 7207 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) 7208 async_submit = 0; 7209 else 7210 async_submit = 1; 7211 7212 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 7213 if (!bio) 7214 return -ENOMEM; 7215 bio->bi_private = dip; 7216 bio->bi_end_io = btrfs_end_dio_bio; 7217 atomic_inc(&dip->pending_bios); 7218 7219 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { 7220 if (unlikely(map_length < submit_len + bvec->bv_len || 7221 bio_add_page(bio, bvec->bv_page, bvec->bv_len, 7222 bvec->bv_offset) < bvec->bv_len)) { 7223 /* 7224 * inc the count before we submit the bio so 7225 * we know the end IO handler won't happen before 7226 * we inc the count. Otherwise, the dip might get freed 7227 * before we're done setting it up 7228 */ 7229 atomic_inc(&dip->pending_bios); 7230 ret = __btrfs_submit_dio_bio(bio, inode, rw, 7231 file_offset, skip_sum, 7232 async_submit); 7233 if (ret) { 7234 bio_put(bio); 7235 atomic_dec(&dip->pending_bios); 7236 goto out_err; 7237 } 7238 7239 start_sector += submit_len >> 9; 7240 file_offset += submit_len; 7241 7242 submit_len = 0; 7243 nr_pages = 0; 7244 7245 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 7246 start_sector, GFP_NOFS); 7247 if (!bio) 7248 goto out_err; 7249 bio->bi_private = dip; 7250 bio->bi_end_io = btrfs_end_dio_bio; 7251 7252 map_length = orig_bio->bi_size; 7253 ret = btrfs_map_block(root->fs_info, rw, 7254 start_sector << 9, 7255 &map_length, NULL, 0); 7256 if (ret) { 7257 bio_put(bio); 7258 goto out_err; 7259 } 7260 } else { 7261 submit_len += bvec->bv_len; 7262 nr_pages++; 7263 bvec++; 7264 } 7265 } 7266 7267 submit: 7268 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, 7269 async_submit); 7270 if (!ret) 7271 return 0; 7272 7273 bio_put(bio); 7274 out_err: 7275 dip->errors = 1; 7276 /* 7277 * before atomic variable goto zero, we must 7278 * make sure dip->errors is perceived to be set. 7279 */ 7280 smp_mb__before_atomic_dec(); 7281 if (atomic_dec_and_test(&dip->pending_bios)) 7282 bio_io_error(dip->orig_bio); 7283 7284 /* bio_end_io() will handle error, so we needn't return it */ 7285 return 0; 7286 } 7287 7288 static void btrfs_submit_direct(int rw, struct bio *dio_bio, 7289 struct inode *inode, loff_t file_offset) 7290 { 7291 struct btrfs_root *root = BTRFS_I(inode)->root; 7292 struct btrfs_dio_private *dip; 7293 struct bio *io_bio; 7294 int skip_sum; 7295 int sum_len; 7296 int write = rw & REQ_WRITE; 7297 int ret = 0; 7298 u16 csum_size; 7299 7300 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 7301 7302 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); 7303 if (!io_bio) { 7304 ret = -ENOMEM; 7305 goto free_ordered; 7306 } 7307 7308 if (!skip_sum && !write) { 7309 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); 7310 sum_len = dio_bio->bi_size >> inode->i_sb->s_blocksize_bits; 7311 sum_len *= csum_size; 7312 } else { 7313 sum_len = 0; 7314 } 7315 7316 dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS); 7317 if (!dip) { 7318 ret = -ENOMEM; 7319 goto free_io_bio; 7320 } 7321 7322 dip->private = dio_bio->bi_private; 7323 dip->inode = inode; 7324 dip->logical_offset = file_offset; 7325 dip->bytes = dio_bio->bi_size; 7326 dip->disk_bytenr = (u64)dio_bio->bi_sector << 9; 7327 io_bio->bi_private = dip; 7328 dip->errors = 0; 7329 dip->orig_bio = io_bio; 7330 dip->dio_bio = dio_bio; 7331 atomic_set(&dip->pending_bios, 0); 7332 7333 if (write) 7334 io_bio->bi_end_io = btrfs_endio_direct_write; 7335 else 7336 io_bio->bi_end_io = btrfs_endio_direct_read; 7337 7338 ret = btrfs_submit_direct_hook(rw, dip, skip_sum); 7339 if (!ret) 7340 return; 7341 7342 free_io_bio: 7343 bio_put(io_bio); 7344 7345 free_ordered: 7346 /* 7347 * If this is a write, we need to clean up the reserved space and kill 7348 * the ordered extent. 7349 */ 7350 if (write) { 7351 struct btrfs_ordered_extent *ordered; 7352 ordered = btrfs_lookup_ordered_extent(inode, file_offset); 7353 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && 7354 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) 7355 btrfs_free_reserved_extent(root, ordered->start, 7356 ordered->disk_len); 7357 btrfs_put_ordered_extent(ordered); 7358 btrfs_put_ordered_extent(ordered); 7359 } 7360 bio_endio(dio_bio, ret); 7361 } 7362 7363 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb, 7364 const struct iovec *iov, loff_t offset, 7365 unsigned long nr_segs) 7366 { 7367 int seg; 7368 int i; 7369 size_t size; 7370 unsigned long addr; 7371 unsigned blocksize_mask = root->sectorsize - 1; 7372 ssize_t retval = -EINVAL; 7373 loff_t end = offset; 7374 7375 if (offset & blocksize_mask) 7376 goto out; 7377 7378 /* Check the memory alignment. Blocks cannot straddle pages */ 7379 for (seg = 0; seg < nr_segs; seg++) { 7380 addr = (unsigned long)iov[seg].iov_base; 7381 size = iov[seg].iov_len; 7382 end += size; 7383 if ((addr & blocksize_mask) || (size & blocksize_mask)) 7384 goto out; 7385 7386 /* If this is a write we don't need to check anymore */ 7387 if (rw & WRITE) 7388 continue; 7389 7390 /* 7391 * Check to make sure we don't have duplicate iov_base's in this 7392 * iovec, if so return EINVAL, otherwise we'll get csum errors 7393 * when reading back. 7394 */ 7395 for (i = seg + 1; i < nr_segs; i++) { 7396 if (iov[seg].iov_base == iov[i].iov_base) 7397 goto out; 7398 } 7399 } 7400 retval = 0; 7401 out: 7402 return retval; 7403 } 7404 7405 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, 7406 const struct iovec *iov, loff_t offset, 7407 unsigned long nr_segs) 7408 { 7409 struct file *file = iocb->ki_filp; 7410 struct inode *inode = file->f_mapping->host; 7411 size_t count = 0; 7412 int flags = 0; 7413 bool wakeup = true; 7414 bool relock = false; 7415 ssize_t ret; 7416 7417 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov, 7418 offset, nr_segs)) 7419 return 0; 7420 7421 atomic_inc(&inode->i_dio_count); 7422 smp_mb__after_atomic_inc(); 7423 7424 /* 7425 * The generic stuff only does filemap_write_and_wait_range, which 7426 * isn't enough if we've written compressed pages to this area, so 7427 * we need to flush the dirty pages again to make absolutely sure 7428 * that any outstanding dirty pages are on disk. 7429 */ 7430 count = iov_length(iov, nr_segs); 7431 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 7432 &BTRFS_I(inode)->runtime_flags)) 7433 filemap_fdatawrite_range(inode->i_mapping, offset, count); 7434 7435 if (rw & WRITE) { 7436 /* 7437 * If the write DIO is beyond the EOF, we need update 7438 * the isize, but it is protected by i_mutex. So we can 7439 * not unlock the i_mutex at this case. 7440 */ 7441 if (offset + count <= inode->i_size) { 7442 mutex_unlock(&inode->i_mutex); 7443 relock = true; 7444 } 7445 ret = btrfs_delalloc_reserve_space(inode, count); 7446 if (ret) 7447 goto out; 7448 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 7449 &BTRFS_I(inode)->runtime_flags))) { 7450 inode_dio_done(inode); 7451 flags = DIO_LOCKING | DIO_SKIP_HOLES; 7452 wakeup = false; 7453 } 7454 7455 ret = __blockdev_direct_IO(rw, iocb, inode, 7456 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, 7457 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL, 7458 btrfs_submit_direct, flags); 7459 if (rw & WRITE) { 7460 if (ret < 0 && ret != -EIOCBQUEUED) 7461 btrfs_delalloc_release_space(inode, count); 7462 else if (ret >= 0 && (size_t)ret < count) 7463 btrfs_delalloc_release_space(inode, 7464 count - (size_t)ret); 7465 else 7466 btrfs_delalloc_release_metadata(inode, 0); 7467 } 7468 out: 7469 if (wakeup) 7470 inode_dio_done(inode); 7471 if (relock) 7472 mutex_lock(&inode->i_mutex); 7473 7474 return ret; 7475 } 7476 7477 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 7478 7479 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 7480 __u64 start, __u64 len) 7481 { 7482 int ret; 7483 7484 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 7485 if (ret) 7486 return ret; 7487 7488 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 7489 } 7490 7491 int btrfs_readpage(struct file *file, struct page *page) 7492 { 7493 struct extent_io_tree *tree; 7494 tree = &BTRFS_I(page->mapping->host)->io_tree; 7495 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 7496 } 7497 7498 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 7499 { 7500 struct extent_io_tree *tree; 7501 7502 7503 if (current->flags & PF_MEMALLOC) { 7504 redirty_page_for_writepage(wbc, page); 7505 unlock_page(page); 7506 return 0; 7507 } 7508 tree = &BTRFS_I(page->mapping->host)->io_tree; 7509 return extent_write_full_page(tree, page, btrfs_get_extent, wbc); 7510 } 7511 7512 static int btrfs_writepages(struct address_space *mapping, 7513 struct writeback_control *wbc) 7514 { 7515 struct extent_io_tree *tree; 7516 7517 tree = &BTRFS_I(mapping->host)->io_tree; 7518 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 7519 } 7520 7521 static int 7522 btrfs_readpages(struct file *file, struct address_space *mapping, 7523 struct list_head *pages, unsigned nr_pages) 7524 { 7525 struct extent_io_tree *tree; 7526 tree = &BTRFS_I(mapping->host)->io_tree; 7527 return extent_readpages(tree, mapping, pages, nr_pages, 7528 btrfs_get_extent); 7529 } 7530 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7531 { 7532 struct extent_io_tree *tree; 7533 struct extent_map_tree *map; 7534 int ret; 7535 7536 tree = &BTRFS_I(page->mapping->host)->io_tree; 7537 map = &BTRFS_I(page->mapping->host)->extent_tree; 7538 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 7539 if (ret == 1) { 7540 ClearPagePrivate(page); 7541 set_page_private(page, 0); 7542 page_cache_release(page); 7543 } 7544 return ret; 7545 } 7546 7547 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7548 { 7549 if (PageWriteback(page) || PageDirty(page)) 7550 return 0; 7551 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); 7552 } 7553 7554 static void btrfs_invalidatepage(struct page *page, unsigned int offset, 7555 unsigned int length) 7556 { 7557 struct inode *inode = page->mapping->host; 7558 struct extent_io_tree *tree; 7559 struct btrfs_ordered_extent *ordered; 7560 struct extent_state *cached_state = NULL; 7561 u64 page_start = page_offset(page); 7562 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 7563 int inode_evicting = inode->i_state & I_FREEING; 7564 7565 /* 7566 * we have the page locked, so new writeback can't start, 7567 * and the dirty bit won't be cleared while we are here. 7568 * 7569 * Wait for IO on this page so that we can safely clear 7570 * the PagePrivate2 bit and do ordered accounting 7571 */ 7572 wait_on_page_writeback(page); 7573 7574 tree = &BTRFS_I(inode)->io_tree; 7575 if (offset) { 7576 btrfs_releasepage(page, GFP_NOFS); 7577 return; 7578 } 7579 7580 if (!inode_evicting) 7581 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 7582 ordered = btrfs_lookup_ordered_extent(inode, page_start); 7583 if (ordered) { 7584 /* 7585 * IO on this page will never be started, so we need 7586 * to account for any ordered extents now 7587 */ 7588 if (!inode_evicting) 7589 clear_extent_bit(tree, page_start, page_end, 7590 EXTENT_DIRTY | EXTENT_DELALLOC | 7591 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 7592 EXTENT_DEFRAG, 1, 0, &cached_state, 7593 GFP_NOFS); 7594 /* 7595 * whoever cleared the private bit is responsible 7596 * for the finish_ordered_io 7597 */ 7598 if (TestClearPagePrivate2(page)) { 7599 struct btrfs_ordered_inode_tree *tree; 7600 u64 new_len; 7601 7602 tree = &BTRFS_I(inode)->ordered_tree; 7603 7604 spin_lock_irq(&tree->lock); 7605 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); 7606 new_len = page_start - ordered->file_offset; 7607 if (new_len < ordered->truncated_len) 7608 ordered->truncated_len = new_len; 7609 spin_unlock_irq(&tree->lock); 7610 7611 if (btrfs_dec_test_ordered_pending(inode, &ordered, 7612 page_start, 7613 PAGE_CACHE_SIZE, 1)) 7614 btrfs_finish_ordered_io(ordered); 7615 } 7616 btrfs_put_ordered_extent(ordered); 7617 if (!inode_evicting) { 7618 cached_state = NULL; 7619 lock_extent_bits(tree, page_start, page_end, 0, 7620 &cached_state); 7621 } 7622 } 7623 7624 if (!inode_evicting) { 7625 clear_extent_bit(tree, page_start, page_end, 7626 EXTENT_LOCKED | EXTENT_DIRTY | 7627 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 7628 EXTENT_DEFRAG, 1, 1, 7629 &cached_state, GFP_NOFS); 7630 7631 __btrfs_releasepage(page, GFP_NOFS); 7632 } 7633 7634 ClearPageChecked(page); 7635 if (PagePrivate(page)) { 7636 ClearPagePrivate(page); 7637 set_page_private(page, 0); 7638 page_cache_release(page); 7639 } 7640 } 7641 7642 /* 7643 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 7644 * called from a page fault handler when a page is first dirtied. Hence we must 7645 * be careful to check for EOF conditions here. We set the page up correctly 7646 * for a written page which means we get ENOSPC checking when writing into 7647 * holes and correct delalloc and unwritten extent mapping on filesystems that 7648 * support these features. 7649 * 7650 * We are not allowed to take the i_mutex here so we have to play games to 7651 * protect against truncate races as the page could now be beyond EOF. Because 7652 * vmtruncate() writes the inode size before removing pages, once we have the 7653 * page lock we can determine safely if the page is beyond EOF. If it is not 7654 * beyond EOF, then the page is guaranteed safe against truncation until we 7655 * unlock the page. 7656 */ 7657 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 7658 { 7659 struct page *page = vmf->page; 7660 struct inode *inode = file_inode(vma->vm_file); 7661 struct btrfs_root *root = BTRFS_I(inode)->root; 7662 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7663 struct btrfs_ordered_extent *ordered; 7664 struct extent_state *cached_state = NULL; 7665 char *kaddr; 7666 unsigned long zero_start; 7667 loff_t size; 7668 int ret; 7669 int reserved = 0; 7670 u64 page_start; 7671 u64 page_end; 7672 7673 sb_start_pagefault(inode->i_sb); 7674 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 7675 if (!ret) { 7676 ret = file_update_time(vma->vm_file); 7677 reserved = 1; 7678 } 7679 if (ret) { 7680 if (ret == -ENOMEM) 7681 ret = VM_FAULT_OOM; 7682 else /* -ENOSPC, -EIO, etc */ 7683 ret = VM_FAULT_SIGBUS; 7684 if (reserved) 7685 goto out; 7686 goto out_noreserve; 7687 } 7688 7689 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 7690 again: 7691 lock_page(page); 7692 size = i_size_read(inode); 7693 page_start = page_offset(page); 7694 page_end = page_start + PAGE_CACHE_SIZE - 1; 7695 7696 if ((page->mapping != inode->i_mapping) || 7697 (page_start >= size)) { 7698 /* page got truncated out from underneath us */ 7699 goto out_unlock; 7700 } 7701 wait_on_page_writeback(page); 7702 7703 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 7704 set_page_extent_mapped(page); 7705 7706 /* 7707 * we can't set the delalloc bits if there are pending ordered 7708 * extents. Drop our locks and wait for them to finish 7709 */ 7710 ordered = btrfs_lookup_ordered_extent(inode, page_start); 7711 if (ordered) { 7712 unlock_extent_cached(io_tree, page_start, page_end, 7713 &cached_state, GFP_NOFS); 7714 unlock_page(page); 7715 btrfs_start_ordered_extent(inode, ordered, 1); 7716 btrfs_put_ordered_extent(ordered); 7717 goto again; 7718 } 7719 7720 /* 7721 * XXX - page_mkwrite gets called every time the page is dirtied, even 7722 * if it was already dirty, so for space accounting reasons we need to 7723 * clear any delalloc bits for the range we are fixing to save. There 7724 * is probably a better way to do this, but for now keep consistent with 7725 * prepare_pages in the normal write path. 7726 */ 7727 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 7728 EXTENT_DIRTY | EXTENT_DELALLOC | 7729 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 7730 0, 0, &cached_state, GFP_NOFS); 7731 7732 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 7733 &cached_state); 7734 if (ret) { 7735 unlock_extent_cached(io_tree, page_start, page_end, 7736 &cached_state, GFP_NOFS); 7737 ret = VM_FAULT_SIGBUS; 7738 goto out_unlock; 7739 } 7740 ret = 0; 7741 7742 /* page is wholly or partially inside EOF */ 7743 if (page_start + PAGE_CACHE_SIZE > size) 7744 zero_start = size & ~PAGE_CACHE_MASK; 7745 else 7746 zero_start = PAGE_CACHE_SIZE; 7747 7748 if (zero_start != PAGE_CACHE_SIZE) { 7749 kaddr = kmap(page); 7750 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); 7751 flush_dcache_page(page); 7752 kunmap(page); 7753 } 7754 ClearPageChecked(page); 7755 set_page_dirty(page); 7756 SetPageUptodate(page); 7757 7758 BTRFS_I(inode)->last_trans = root->fs_info->generation; 7759 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 7760 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 7761 7762 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 7763 7764 out_unlock: 7765 if (!ret) { 7766 sb_end_pagefault(inode->i_sb); 7767 return VM_FAULT_LOCKED; 7768 } 7769 unlock_page(page); 7770 out: 7771 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 7772 out_noreserve: 7773 sb_end_pagefault(inode->i_sb); 7774 return ret; 7775 } 7776 7777 static int btrfs_truncate(struct inode *inode) 7778 { 7779 struct btrfs_root *root = BTRFS_I(inode)->root; 7780 struct btrfs_block_rsv *rsv; 7781 int ret = 0; 7782 int err = 0; 7783 struct btrfs_trans_handle *trans; 7784 u64 mask = root->sectorsize - 1; 7785 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 7786 7787 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), 7788 (u64)-1); 7789 if (ret) 7790 return ret; 7791 7792 /* 7793 * Yes ladies and gentelment, this is indeed ugly. The fact is we have 7794 * 3 things going on here 7795 * 7796 * 1) We need to reserve space for our orphan item and the space to 7797 * delete our orphan item. Lord knows we don't want to have a dangling 7798 * orphan item because we didn't reserve space to remove it. 7799 * 7800 * 2) We need to reserve space to update our inode. 7801 * 7802 * 3) We need to have something to cache all the space that is going to 7803 * be free'd up by the truncate operation, but also have some slack 7804 * space reserved in case it uses space during the truncate (thank you 7805 * very much snapshotting). 7806 * 7807 * And we need these to all be seperate. The fact is we can use alot of 7808 * space doing the truncate, and we have no earthly idea how much space 7809 * we will use, so we need the truncate reservation to be seperate so it 7810 * doesn't end up using space reserved for updating the inode or 7811 * removing the orphan item. We also need to be able to stop the 7812 * transaction and start a new one, which means we need to be able to 7813 * update the inode several times, and we have no idea of knowing how 7814 * many times that will be, so we can't just reserve 1 item for the 7815 * entirety of the opration, so that has to be done seperately as well. 7816 * Then there is the orphan item, which does indeed need to be held on 7817 * to for the whole operation, and we need nobody to touch this reserved 7818 * space except the orphan code. 7819 * 7820 * So that leaves us with 7821 * 7822 * 1) root->orphan_block_rsv - for the orphan deletion. 7823 * 2) rsv - for the truncate reservation, which we will steal from the 7824 * transaction reservation. 7825 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 7826 * updating the inode. 7827 */ 7828 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 7829 if (!rsv) 7830 return -ENOMEM; 7831 rsv->size = min_size; 7832 rsv->failfast = 1; 7833 7834 /* 7835 * 1 for the truncate slack space 7836 * 1 for updating the inode. 7837 */ 7838 trans = btrfs_start_transaction(root, 2); 7839 if (IS_ERR(trans)) { 7840 err = PTR_ERR(trans); 7841 goto out; 7842 } 7843 7844 /* Migrate the slack space for the truncate to our reserve */ 7845 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, 7846 min_size); 7847 BUG_ON(ret); 7848 7849 /* 7850 * setattr is responsible for setting the ordered_data_close flag, 7851 * but that is only tested during the last file release. That 7852 * could happen well after the next commit, leaving a great big 7853 * window where new writes may get lost if someone chooses to write 7854 * to this file after truncating to zero 7855 * 7856 * The inode doesn't have any dirty data here, and so if we commit 7857 * this is a noop. If someone immediately starts writing to the inode 7858 * it is very likely we'll catch some of their writes in this 7859 * transaction, and the commit will find this file on the ordered 7860 * data list with good things to send down. 7861 * 7862 * This is a best effort solution, there is still a window where 7863 * using truncate to replace the contents of the file will 7864 * end up with a zero length file after a crash. 7865 */ 7866 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 7867 &BTRFS_I(inode)->runtime_flags)) 7868 btrfs_add_ordered_operation(trans, root, inode); 7869 7870 /* 7871 * So if we truncate and then write and fsync we normally would just 7872 * write the extents that changed, which is a problem if we need to 7873 * first truncate that entire inode. So set this flag so we write out 7874 * all of the extents in the inode to the sync log so we're completely 7875 * safe. 7876 */ 7877 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 7878 trans->block_rsv = rsv; 7879 7880 while (1) { 7881 ret = btrfs_truncate_inode_items(trans, root, inode, 7882 inode->i_size, 7883 BTRFS_EXTENT_DATA_KEY); 7884 if (ret != -ENOSPC) { 7885 err = ret; 7886 break; 7887 } 7888 7889 trans->block_rsv = &root->fs_info->trans_block_rsv; 7890 ret = btrfs_update_inode(trans, root, inode); 7891 if (ret) { 7892 err = ret; 7893 break; 7894 } 7895 7896 btrfs_end_transaction(trans, root); 7897 btrfs_btree_balance_dirty(root); 7898 7899 trans = btrfs_start_transaction(root, 2); 7900 if (IS_ERR(trans)) { 7901 ret = err = PTR_ERR(trans); 7902 trans = NULL; 7903 break; 7904 } 7905 7906 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, 7907 rsv, min_size); 7908 BUG_ON(ret); /* shouldn't happen */ 7909 trans->block_rsv = rsv; 7910 } 7911 7912 if (ret == 0 && inode->i_nlink > 0) { 7913 trans->block_rsv = root->orphan_block_rsv; 7914 ret = btrfs_orphan_del(trans, inode); 7915 if (ret) 7916 err = ret; 7917 } 7918 7919 if (trans) { 7920 trans->block_rsv = &root->fs_info->trans_block_rsv; 7921 ret = btrfs_update_inode(trans, root, inode); 7922 if (ret && !err) 7923 err = ret; 7924 7925 ret = btrfs_end_transaction(trans, root); 7926 btrfs_btree_balance_dirty(root); 7927 } 7928 7929 out: 7930 btrfs_free_block_rsv(root, rsv); 7931 7932 if (ret && !err) 7933 err = ret; 7934 7935 return err; 7936 } 7937 7938 /* 7939 * create a new subvolume directory/inode (helper for the ioctl). 7940 */ 7941 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 7942 struct btrfs_root *new_root, 7943 struct btrfs_root *parent_root, 7944 u64 new_dirid) 7945 { 7946 struct inode *inode; 7947 int err; 7948 u64 index = 0; 7949 7950 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 7951 new_dirid, new_dirid, 7952 S_IFDIR | (~current_umask() & S_IRWXUGO), 7953 &index); 7954 if (IS_ERR(inode)) 7955 return PTR_ERR(inode); 7956 inode->i_op = &btrfs_dir_inode_operations; 7957 inode->i_fop = &btrfs_dir_file_operations; 7958 7959 set_nlink(inode, 1); 7960 btrfs_i_size_write(inode, 0); 7961 7962 err = btrfs_subvol_inherit_props(trans, new_root, parent_root); 7963 if (err) 7964 btrfs_err(new_root->fs_info, 7965 "error inheriting subvolume %llu properties: %d\n", 7966 new_root->root_key.objectid, err); 7967 7968 err = btrfs_update_inode(trans, new_root, inode); 7969 7970 iput(inode); 7971 return err; 7972 } 7973 7974 struct inode *btrfs_alloc_inode(struct super_block *sb) 7975 { 7976 struct btrfs_inode *ei; 7977 struct inode *inode; 7978 7979 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 7980 if (!ei) 7981 return NULL; 7982 7983 ei->root = NULL; 7984 ei->generation = 0; 7985 ei->last_trans = 0; 7986 ei->last_sub_trans = 0; 7987 ei->logged_trans = 0; 7988 ei->delalloc_bytes = 0; 7989 ei->disk_i_size = 0; 7990 ei->flags = 0; 7991 ei->csum_bytes = 0; 7992 ei->index_cnt = (u64)-1; 7993 ei->dir_index = 0; 7994 ei->last_unlink_trans = 0; 7995 ei->last_log_commit = 0; 7996 7997 spin_lock_init(&ei->lock); 7998 ei->outstanding_extents = 0; 7999 ei->reserved_extents = 0; 8000 8001 ei->runtime_flags = 0; 8002 ei->force_compress = BTRFS_COMPRESS_NONE; 8003 8004 ei->delayed_node = NULL; 8005 8006 inode = &ei->vfs_inode; 8007 extent_map_tree_init(&ei->extent_tree); 8008 extent_io_tree_init(&ei->io_tree, &inode->i_data); 8009 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 8010 ei->io_tree.track_uptodate = 1; 8011 ei->io_failure_tree.track_uptodate = 1; 8012 atomic_set(&ei->sync_writers, 0); 8013 mutex_init(&ei->log_mutex); 8014 mutex_init(&ei->delalloc_mutex); 8015 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 8016 INIT_LIST_HEAD(&ei->delalloc_inodes); 8017 INIT_LIST_HEAD(&ei->ordered_operations); 8018 RB_CLEAR_NODE(&ei->rb_node); 8019 8020 return inode; 8021 } 8022 8023 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 8024 void btrfs_test_destroy_inode(struct inode *inode) 8025 { 8026 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 8027 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 8028 } 8029 #endif 8030 8031 static void btrfs_i_callback(struct rcu_head *head) 8032 { 8033 struct inode *inode = container_of(head, struct inode, i_rcu); 8034 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 8035 } 8036 8037 void btrfs_destroy_inode(struct inode *inode) 8038 { 8039 struct btrfs_ordered_extent *ordered; 8040 struct btrfs_root *root = BTRFS_I(inode)->root; 8041 8042 WARN_ON(!hlist_empty(&inode->i_dentry)); 8043 WARN_ON(inode->i_data.nrpages); 8044 WARN_ON(BTRFS_I(inode)->outstanding_extents); 8045 WARN_ON(BTRFS_I(inode)->reserved_extents); 8046 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 8047 WARN_ON(BTRFS_I(inode)->csum_bytes); 8048 8049 /* 8050 * This can happen where we create an inode, but somebody else also 8051 * created the same inode and we need to destroy the one we already 8052 * created. 8053 */ 8054 if (!root) 8055 goto free; 8056 8057 /* 8058 * Make sure we're properly removed from the ordered operation 8059 * lists. 8060 */ 8061 smp_mb(); 8062 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) { 8063 spin_lock(&root->fs_info->ordered_root_lock); 8064 list_del_init(&BTRFS_I(inode)->ordered_operations); 8065 spin_unlock(&root->fs_info->ordered_root_lock); 8066 } 8067 8068 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 8069 &BTRFS_I(inode)->runtime_flags)) { 8070 btrfs_info(root->fs_info, "inode %llu still on the orphan list", 8071 btrfs_ino(inode)); 8072 atomic_dec(&root->orphan_inodes); 8073 } 8074 8075 while (1) { 8076 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 8077 if (!ordered) 8078 break; 8079 else { 8080 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", 8081 ordered->file_offset, ordered->len); 8082 btrfs_remove_ordered_extent(inode, ordered); 8083 btrfs_put_ordered_extent(ordered); 8084 btrfs_put_ordered_extent(ordered); 8085 } 8086 } 8087 inode_tree_del(inode); 8088 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 8089 free: 8090 call_rcu(&inode->i_rcu, btrfs_i_callback); 8091 } 8092 8093 int btrfs_drop_inode(struct inode *inode) 8094 { 8095 struct btrfs_root *root = BTRFS_I(inode)->root; 8096 8097 if (root == NULL) 8098 return 1; 8099 8100 /* the snap/subvol tree is on deleting */ 8101 if (btrfs_root_refs(&root->root_item) == 0) 8102 return 1; 8103 else 8104 return generic_drop_inode(inode); 8105 } 8106 8107 static void init_once(void *foo) 8108 { 8109 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 8110 8111 inode_init_once(&ei->vfs_inode); 8112 } 8113 8114 void btrfs_destroy_cachep(void) 8115 { 8116 /* 8117 * Make sure all delayed rcu free inodes are flushed before we 8118 * destroy cache. 8119 */ 8120 rcu_barrier(); 8121 if (btrfs_inode_cachep) 8122 kmem_cache_destroy(btrfs_inode_cachep); 8123 if (btrfs_trans_handle_cachep) 8124 kmem_cache_destroy(btrfs_trans_handle_cachep); 8125 if (btrfs_transaction_cachep) 8126 kmem_cache_destroy(btrfs_transaction_cachep); 8127 if (btrfs_path_cachep) 8128 kmem_cache_destroy(btrfs_path_cachep); 8129 if (btrfs_free_space_cachep) 8130 kmem_cache_destroy(btrfs_free_space_cachep); 8131 if (btrfs_delalloc_work_cachep) 8132 kmem_cache_destroy(btrfs_delalloc_work_cachep); 8133 } 8134 8135 int btrfs_init_cachep(void) 8136 { 8137 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 8138 sizeof(struct btrfs_inode), 0, 8139 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); 8140 if (!btrfs_inode_cachep) 8141 goto fail; 8142 8143 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 8144 sizeof(struct btrfs_trans_handle), 0, 8145 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8146 if (!btrfs_trans_handle_cachep) 8147 goto fail; 8148 8149 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 8150 sizeof(struct btrfs_transaction), 0, 8151 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8152 if (!btrfs_transaction_cachep) 8153 goto fail; 8154 8155 btrfs_path_cachep = kmem_cache_create("btrfs_path", 8156 sizeof(struct btrfs_path), 0, 8157 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8158 if (!btrfs_path_cachep) 8159 goto fail; 8160 8161 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 8162 sizeof(struct btrfs_free_space), 0, 8163 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8164 if (!btrfs_free_space_cachep) 8165 goto fail; 8166 8167 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work", 8168 sizeof(struct btrfs_delalloc_work), 0, 8169 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 8170 NULL); 8171 if (!btrfs_delalloc_work_cachep) 8172 goto fail; 8173 8174 return 0; 8175 fail: 8176 btrfs_destroy_cachep(); 8177 return -ENOMEM; 8178 } 8179 8180 static int btrfs_getattr(struct vfsmount *mnt, 8181 struct dentry *dentry, struct kstat *stat) 8182 { 8183 u64 delalloc_bytes; 8184 struct inode *inode = dentry->d_inode; 8185 u32 blocksize = inode->i_sb->s_blocksize; 8186 8187 generic_fillattr(inode, stat); 8188 stat->dev = BTRFS_I(inode)->root->anon_dev; 8189 stat->blksize = PAGE_CACHE_SIZE; 8190 8191 spin_lock(&BTRFS_I(inode)->lock); 8192 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 8193 spin_unlock(&BTRFS_I(inode)->lock); 8194 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 8195 ALIGN(delalloc_bytes, blocksize)) >> 9; 8196 return 0; 8197 } 8198 8199 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 8200 struct inode *new_dir, struct dentry *new_dentry) 8201 { 8202 struct btrfs_trans_handle *trans; 8203 struct btrfs_root *root = BTRFS_I(old_dir)->root; 8204 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 8205 struct inode *new_inode = new_dentry->d_inode; 8206 struct inode *old_inode = old_dentry->d_inode; 8207 struct timespec ctime = CURRENT_TIME; 8208 u64 index = 0; 8209 u64 root_objectid; 8210 int ret; 8211 u64 old_ino = btrfs_ino(old_inode); 8212 8213 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 8214 return -EPERM; 8215 8216 /* we only allow rename subvolume link between subvolumes */ 8217 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 8218 return -EXDEV; 8219 8220 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 8221 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) 8222 return -ENOTEMPTY; 8223 8224 if (S_ISDIR(old_inode->i_mode) && new_inode && 8225 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 8226 return -ENOTEMPTY; 8227 8228 8229 /* check for collisions, even if the name isn't there */ 8230 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, 8231 new_dentry->d_name.name, 8232 new_dentry->d_name.len); 8233 8234 if (ret) { 8235 if (ret == -EEXIST) { 8236 /* we shouldn't get 8237 * eexist without a new_inode */ 8238 if (WARN_ON(!new_inode)) { 8239 return ret; 8240 } 8241 } else { 8242 /* maybe -EOVERFLOW */ 8243 return ret; 8244 } 8245 } 8246 ret = 0; 8247 8248 /* 8249 * we're using rename to replace one file with another. 8250 * and the replacement file is large. Start IO on it now so 8251 * we don't add too much work to the end of the transaction 8252 */ 8253 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size && 8254 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) 8255 filemap_flush(old_inode->i_mapping); 8256 8257 /* close the racy window with snapshot create/destroy ioctl */ 8258 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8259 down_read(&root->fs_info->subvol_sem); 8260 /* 8261 * We want to reserve the absolute worst case amount of items. So if 8262 * both inodes are subvols and we need to unlink them then that would 8263 * require 4 item modifications, but if they are both normal inodes it 8264 * would require 5 item modifications, so we'll assume their normal 8265 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 8266 * should cover the worst case number of items we'll modify. 8267 */ 8268 trans = btrfs_start_transaction(root, 11); 8269 if (IS_ERR(trans)) { 8270 ret = PTR_ERR(trans); 8271 goto out_notrans; 8272 } 8273 8274 if (dest != root) 8275 btrfs_record_root_in_trans(trans, dest); 8276 8277 ret = btrfs_set_inode_index(new_dir, &index); 8278 if (ret) 8279 goto out_fail; 8280 8281 BTRFS_I(old_inode)->dir_index = 0ULL; 8282 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8283 /* force full log commit if subvolume involved. */ 8284 root->fs_info->last_trans_log_full_commit = trans->transid; 8285 } else { 8286 ret = btrfs_insert_inode_ref(trans, dest, 8287 new_dentry->d_name.name, 8288 new_dentry->d_name.len, 8289 old_ino, 8290 btrfs_ino(new_dir), index); 8291 if (ret) 8292 goto out_fail; 8293 /* 8294 * this is an ugly little race, but the rename is required 8295 * to make sure that if we crash, the inode is either at the 8296 * old name or the new one. pinning the log transaction lets 8297 * us make sure we don't allow a log commit to come in after 8298 * we unlink the name but before we add the new name back in. 8299 */ 8300 btrfs_pin_log_trans(root); 8301 } 8302 /* 8303 * make sure the inode gets flushed if it is replacing 8304 * something. 8305 */ 8306 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode)) 8307 btrfs_add_ordered_operation(trans, root, old_inode); 8308 8309 inode_inc_iversion(old_dir); 8310 inode_inc_iversion(new_dir); 8311 inode_inc_iversion(old_inode); 8312 old_dir->i_ctime = old_dir->i_mtime = ctime; 8313 new_dir->i_ctime = new_dir->i_mtime = ctime; 8314 old_inode->i_ctime = ctime; 8315 8316 if (old_dentry->d_parent != new_dentry->d_parent) 8317 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); 8318 8319 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8320 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 8321 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 8322 old_dentry->d_name.name, 8323 old_dentry->d_name.len); 8324 } else { 8325 ret = __btrfs_unlink_inode(trans, root, old_dir, 8326 old_dentry->d_inode, 8327 old_dentry->d_name.name, 8328 old_dentry->d_name.len); 8329 if (!ret) 8330 ret = btrfs_update_inode(trans, root, old_inode); 8331 } 8332 if (ret) { 8333 btrfs_abort_transaction(trans, root, ret); 8334 goto out_fail; 8335 } 8336 8337 if (new_inode) { 8338 inode_inc_iversion(new_inode); 8339 new_inode->i_ctime = CURRENT_TIME; 8340 if (unlikely(btrfs_ino(new_inode) == 8341 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 8342 root_objectid = BTRFS_I(new_inode)->location.objectid; 8343 ret = btrfs_unlink_subvol(trans, dest, new_dir, 8344 root_objectid, 8345 new_dentry->d_name.name, 8346 new_dentry->d_name.len); 8347 BUG_ON(new_inode->i_nlink == 0); 8348 } else { 8349 ret = btrfs_unlink_inode(trans, dest, new_dir, 8350 new_dentry->d_inode, 8351 new_dentry->d_name.name, 8352 new_dentry->d_name.len); 8353 } 8354 if (!ret && new_inode->i_nlink == 0) 8355 ret = btrfs_orphan_add(trans, new_dentry->d_inode); 8356 if (ret) { 8357 btrfs_abort_transaction(trans, root, ret); 8358 goto out_fail; 8359 } 8360 } 8361 8362 ret = btrfs_add_link(trans, new_dir, old_inode, 8363 new_dentry->d_name.name, 8364 new_dentry->d_name.len, 0, index); 8365 if (ret) { 8366 btrfs_abort_transaction(trans, root, ret); 8367 goto out_fail; 8368 } 8369 8370 if (old_inode->i_nlink == 1) 8371 BTRFS_I(old_inode)->dir_index = index; 8372 8373 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { 8374 struct dentry *parent = new_dentry->d_parent; 8375 btrfs_log_new_name(trans, old_inode, old_dir, parent); 8376 btrfs_end_log_trans(root); 8377 } 8378 out_fail: 8379 btrfs_end_transaction(trans, root); 8380 out_notrans: 8381 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8382 up_read(&root->fs_info->subvol_sem); 8383 8384 return ret; 8385 } 8386 8387 static void btrfs_run_delalloc_work(struct btrfs_work *work) 8388 { 8389 struct btrfs_delalloc_work *delalloc_work; 8390 struct inode *inode; 8391 8392 delalloc_work = container_of(work, struct btrfs_delalloc_work, 8393 work); 8394 inode = delalloc_work->inode; 8395 if (delalloc_work->wait) { 8396 btrfs_wait_ordered_range(inode, 0, (u64)-1); 8397 } else { 8398 filemap_flush(inode->i_mapping); 8399 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 8400 &BTRFS_I(inode)->runtime_flags)) 8401 filemap_flush(inode->i_mapping); 8402 } 8403 8404 if (delalloc_work->delay_iput) 8405 btrfs_add_delayed_iput(inode); 8406 else 8407 iput(inode); 8408 complete(&delalloc_work->completion); 8409 } 8410 8411 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 8412 int wait, int delay_iput) 8413 { 8414 struct btrfs_delalloc_work *work; 8415 8416 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS); 8417 if (!work) 8418 return NULL; 8419 8420 init_completion(&work->completion); 8421 INIT_LIST_HEAD(&work->list); 8422 work->inode = inode; 8423 work->wait = wait; 8424 work->delay_iput = delay_iput; 8425 btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL); 8426 8427 return work; 8428 } 8429 8430 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 8431 { 8432 wait_for_completion(&work->completion); 8433 kmem_cache_free(btrfs_delalloc_work_cachep, work); 8434 } 8435 8436 /* 8437 * some fairly slow code that needs optimization. This walks the list 8438 * of all the inodes with pending delalloc and forces them to disk. 8439 */ 8440 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8441 { 8442 struct btrfs_inode *binode; 8443 struct inode *inode; 8444 struct btrfs_delalloc_work *work, *next; 8445 struct list_head works; 8446 struct list_head splice; 8447 int ret = 0; 8448 8449 INIT_LIST_HEAD(&works); 8450 INIT_LIST_HEAD(&splice); 8451 8452 spin_lock(&root->delalloc_lock); 8453 list_splice_init(&root->delalloc_inodes, &splice); 8454 while (!list_empty(&splice)) { 8455 binode = list_entry(splice.next, struct btrfs_inode, 8456 delalloc_inodes); 8457 8458 list_move_tail(&binode->delalloc_inodes, 8459 &root->delalloc_inodes); 8460 inode = igrab(&binode->vfs_inode); 8461 if (!inode) { 8462 cond_resched_lock(&root->delalloc_lock); 8463 continue; 8464 } 8465 spin_unlock(&root->delalloc_lock); 8466 8467 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput); 8468 if (unlikely(!work)) { 8469 if (delay_iput) 8470 btrfs_add_delayed_iput(inode); 8471 else 8472 iput(inode); 8473 ret = -ENOMEM; 8474 goto out; 8475 } 8476 list_add_tail(&work->list, &works); 8477 btrfs_queue_work(root->fs_info->flush_workers, 8478 &work->work); 8479 8480 cond_resched(); 8481 spin_lock(&root->delalloc_lock); 8482 } 8483 spin_unlock(&root->delalloc_lock); 8484 8485 list_for_each_entry_safe(work, next, &works, list) { 8486 list_del_init(&work->list); 8487 btrfs_wait_and_free_delalloc_work(work); 8488 } 8489 return 0; 8490 out: 8491 list_for_each_entry_safe(work, next, &works, list) { 8492 list_del_init(&work->list); 8493 btrfs_wait_and_free_delalloc_work(work); 8494 } 8495 8496 if (!list_empty_careful(&splice)) { 8497 spin_lock(&root->delalloc_lock); 8498 list_splice_tail(&splice, &root->delalloc_inodes); 8499 spin_unlock(&root->delalloc_lock); 8500 } 8501 return ret; 8502 } 8503 8504 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8505 { 8506 int ret; 8507 8508 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 8509 return -EROFS; 8510 8511 ret = __start_delalloc_inodes(root, delay_iput); 8512 /* 8513 * the filemap_flush will queue IO into the worker threads, but 8514 * we have to make sure the IO is actually started and that 8515 * ordered extents get created before we return 8516 */ 8517 atomic_inc(&root->fs_info->async_submit_draining); 8518 while (atomic_read(&root->fs_info->nr_async_submits) || 8519 atomic_read(&root->fs_info->async_delalloc_pages)) { 8520 wait_event(root->fs_info->async_submit_wait, 8521 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 8522 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 8523 } 8524 atomic_dec(&root->fs_info->async_submit_draining); 8525 return ret; 8526 } 8527 8528 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput) 8529 { 8530 struct btrfs_root *root; 8531 struct list_head splice; 8532 int ret; 8533 8534 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 8535 return -EROFS; 8536 8537 INIT_LIST_HEAD(&splice); 8538 8539 spin_lock(&fs_info->delalloc_root_lock); 8540 list_splice_init(&fs_info->delalloc_roots, &splice); 8541 while (!list_empty(&splice)) { 8542 root = list_first_entry(&splice, struct btrfs_root, 8543 delalloc_root); 8544 root = btrfs_grab_fs_root(root); 8545 BUG_ON(!root); 8546 list_move_tail(&root->delalloc_root, 8547 &fs_info->delalloc_roots); 8548 spin_unlock(&fs_info->delalloc_root_lock); 8549 8550 ret = __start_delalloc_inodes(root, delay_iput); 8551 btrfs_put_fs_root(root); 8552 if (ret) 8553 goto out; 8554 8555 spin_lock(&fs_info->delalloc_root_lock); 8556 } 8557 spin_unlock(&fs_info->delalloc_root_lock); 8558 8559 atomic_inc(&fs_info->async_submit_draining); 8560 while (atomic_read(&fs_info->nr_async_submits) || 8561 atomic_read(&fs_info->async_delalloc_pages)) { 8562 wait_event(fs_info->async_submit_wait, 8563 (atomic_read(&fs_info->nr_async_submits) == 0 && 8564 atomic_read(&fs_info->async_delalloc_pages) == 0)); 8565 } 8566 atomic_dec(&fs_info->async_submit_draining); 8567 return 0; 8568 out: 8569 if (!list_empty_careful(&splice)) { 8570 spin_lock(&fs_info->delalloc_root_lock); 8571 list_splice_tail(&splice, &fs_info->delalloc_roots); 8572 spin_unlock(&fs_info->delalloc_root_lock); 8573 } 8574 return ret; 8575 } 8576 8577 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 8578 const char *symname) 8579 { 8580 struct btrfs_trans_handle *trans; 8581 struct btrfs_root *root = BTRFS_I(dir)->root; 8582 struct btrfs_path *path; 8583 struct btrfs_key key; 8584 struct inode *inode = NULL; 8585 int err; 8586 int drop_inode = 0; 8587 u64 objectid; 8588 u64 index = 0; 8589 int name_len; 8590 int datasize; 8591 unsigned long ptr; 8592 struct btrfs_file_extent_item *ei; 8593 struct extent_buffer *leaf; 8594 8595 name_len = strlen(symname); 8596 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) 8597 return -ENAMETOOLONG; 8598 8599 /* 8600 * 2 items for inode item and ref 8601 * 2 items for dir items 8602 * 1 item for xattr if selinux is on 8603 */ 8604 trans = btrfs_start_transaction(root, 5); 8605 if (IS_ERR(trans)) 8606 return PTR_ERR(trans); 8607 8608 err = btrfs_find_free_ino(root, &objectid); 8609 if (err) 8610 goto out_unlock; 8611 8612 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 8613 dentry->d_name.len, btrfs_ino(dir), objectid, 8614 S_IFLNK|S_IRWXUGO, &index); 8615 if (IS_ERR(inode)) { 8616 err = PTR_ERR(inode); 8617 goto out_unlock; 8618 } 8619 8620 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 8621 if (err) { 8622 drop_inode = 1; 8623 goto out_unlock; 8624 } 8625 8626 /* 8627 * If the active LSM wants to access the inode during 8628 * d_instantiate it needs these. Smack checks to see 8629 * if the filesystem supports xattrs by looking at the 8630 * ops vector. 8631 */ 8632 inode->i_fop = &btrfs_file_operations; 8633 inode->i_op = &btrfs_file_inode_operations; 8634 8635 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 8636 if (err) 8637 drop_inode = 1; 8638 else { 8639 inode->i_mapping->a_ops = &btrfs_aops; 8640 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8641 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 8642 } 8643 if (drop_inode) 8644 goto out_unlock; 8645 8646 path = btrfs_alloc_path(); 8647 if (!path) { 8648 err = -ENOMEM; 8649 drop_inode = 1; 8650 goto out_unlock; 8651 } 8652 key.objectid = btrfs_ino(inode); 8653 key.offset = 0; 8654 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 8655 datasize = btrfs_file_extent_calc_inline_size(name_len); 8656 err = btrfs_insert_empty_item(trans, root, path, &key, 8657 datasize); 8658 if (err) { 8659 drop_inode = 1; 8660 btrfs_free_path(path); 8661 goto out_unlock; 8662 } 8663 leaf = path->nodes[0]; 8664 ei = btrfs_item_ptr(leaf, path->slots[0], 8665 struct btrfs_file_extent_item); 8666 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 8667 btrfs_set_file_extent_type(leaf, ei, 8668 BTRFS_FILE_EXTENT_INLINE); 8669 btrfs_set_file_extent_encryption(leaf, ei, 0); 8670 btrfs_set_file_extent_compression(leaf, ei, 0); 8671 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 8672 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 8673 8674 ptr = btrfs_file_extent_inline_start(ei); 8675 write_extent_buffer(leaf, symname, ptr, name_len); 8676 btrfs_mark_buffer_dirty(leaf); 8677 btrfs_free_path(path); 8678 8679 inode->i_op = &btrfs_symlink_inode_operations; 8680 inode->i_mapping->a_ops = &btrfs_symlink_aops; 8681 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8682 inode_set_bytes(inode, name_len); 8683 btrfs_i_size_write(inode, name_len); 8684 err = btrfs_update_inode(trans, root, inode); 8685 if (err) 8686 drop_inode = 1; 8687 8688 out_unlock: 8689 if (!err) 8690 d_instantiate(dentry, inode); 8691 btrfs_end_transaction(trans, root); 8692 if (drop_inode) { 8693 inode_dec_link_count(inode); 8694 iput(inode); 8695 } 8696 btrfs_btree_balance_dirty(root); 8697 return err; 8698 } 8699 8700 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 8701 u64 start, u64 num_bytes, u64 min_size, 8702 loff_t actual_len, u64 *alloc_hint, 8703 struct btrfs_trans_handle *trans) 8704 { 8705 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 8706 struct extent_map *em; 8707 struct btrfs_root *root = BTRFS_I(inode)->root; 8708 struct btrfs_key ins; 8709 u64 cur_offset = start; 8710 u64 i_size; 8711 u64 cur_bytes; 8712 int ret = 0; 8713 bool own_trans = true; 8714 8715 if (trans) 8716 own_trans = false; 8717 while (num_bytes > 0) { 8718 if (own_trans) { 8719 trans = btrfs_start_transaction(root, 3); 8720 if (IS_ERR(trans)) { 8721 ret = PTR_ERR(trans); 8722 break; 8723 } 8724 } 8725 8726 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024); 8727 cur_bytes = max(cur_bytes, min_size); 8728 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0, 8729 *alloc_hint, &ins, 1); 8730 if (ret) { 8731 if (own_trans) 8732 btrfs_end_transaction(trans, root); 8733 break; 8734 } 8735 8736 ret = insert_reserved_file_extent(trans, inode, 8737 cur_offset, ins.objectid, 8738 ins.offset, ins.offset, 8739 ins.offset, 0, 0, 0, 8740 BTRFS_FILE_EXTENT_PREALLOC); 8741 if (ret) { 8742 btrfs_free_reserved_extent(root, ins.objectid, 8743 ins.offset); 8744 btrfs_abort_transaction(trans, root, ret); 8745 if (own_trans) 8746 btrfs_end_transaction(trans, root); 8747 break; 8748 } 8749 btrfs_drop_extent_cache(inode, cur_offset, 8750 cur_offset + ins.offset -1, 0); 8751 8752 em = alloc_extent_map(); 8753 if (!em) { 8754 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 8755 &BTRFS_I(inode)->runtime_flags); 8756 goto next; 8757 } 8758 8759 em->start = cur_offset; 8760 em->orig_start = cur_offset; 8761 em->len = ins.offset; 8762 em->block_start = ins.objectid; 8763 em->block_len = ins.offset; 8764 em->orig_block_len = ins.offset; 8765 em->ram_bytes = ins.offset; 8766 em->bdev = root->fs_info->fs_devices->latest_bdev; 8767 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 8768 em->generation = trans->transid; 8769 8770 while (1) { 8771 write_lock(&em_tree->lock); 8772 ret = add_extent_mapping(em_tree, em, 1); 8773 write_unlock(&em_tree->lock); 8774 if (ret != -EEXIST) 8775 break; 8776 btrfs_drop_extent_cache(inode, cur_offset, 8777 cur_offset + ins.offset - 1, 8778 0); 8779 } 8780 free_extent_map(em); 8781 next: 8782 num_bytes -= ins.offset; 8783 cur_offset += ins.offset; 8784 *alloc_hint = ins.objectid + ins.offset; 8785 8786 inode_inc_iversion(inode); 8787 inode->i_ctime = CURRENT_TIME; 8788 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 8789 if (!(mode & FALLOC_FL_KEEP_SIZE) && 8790 (actual_len > inode->i_size) && 8791 (cur_offset > inode->i_size)) { 8792 if (cur_offset > actual_len) 8793 i_size = actual_len; 8794 else 8795 i_size = cur_offset; 8796 i_size_write(inode, i_size); 8797 btrfs_ordered_update_i_size(inode, i_size, NULL); 8798 } 8799 8800 ret = btrfs_update_inode(trans, root, inode); 8801 8802 if (ret) { 8803 btrfs_abort_transaction(trans, root, ret); 8804 if (own_trans) 8805 btrfs_end_transaction(trans, root); 8806 break; 8807 } 8808 8809 if (own_trans) 8810 btrfs_end_transaction(trans, root); 8811 } 8812 return ret; 8813 } 8814 8815 int btrfs_prealloc_file_range(struct inode *inode, int mode, 8816 u64 start, u64 num_bytes, u64 min_size, 8817 loff_t actual_len, u64 *alloc_hint) 8818 { 8819 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8820 min_size, actual_len, alloc_hint, 8821 NULL); 8822 } 8823 8824 int btrfs_prealloc_file_range_trans(struct inode *inode, 8825 struct btrfs_trans_handle *trans, int mode, 8826 u64 start, u64 num_bytes, u64 min_size, 8827 loff_t actual_len, u64 *alloc_hint) 8828 { 8829 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8830 min_size, actual_len, alloc_hint, trans); 8831 } 8832 8833 static int btrfs_set_page_dirty(struct page *page) 8834 { 8835 return __set_page_dirty_nobuffers(page); 8836 } 8837 8838 static int btrfs_permission(struct inode *inode, int mask) 8839 { 8840 struct btrfs_root *root = BTRFS_I(inode)->root; 8841 umode_t mode = inode->i_mode; 8842 8843 if (mask & MAY_WRITE && 8844 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 8845 if (btrfs_root_readonly(root)) 8846 return -EROFS; 8847 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 8848 return -EACCES; 8849 } 8850 return generic_permission(inode, mask); 8851 } 8852 8853 static const struct inode_operations btrfs_dir_inode_operations = { 8854 .getattr = btrfs_getattr, 8855 .lookup = btrfs_lookup, 8856 .create = btrfs_create, 8857 .unlink = btrfs_unlink, 8858 .link = btrfs_link, 8859 .mkdir = btrfs_mkdir, 8860 .rmdir = btrfs_rmdir, 8861 .rename = btrfs_rename, 8862 .symlink = btrfs_symlink, 8863 .setattr = btrfs_setattr, 8864 .mknod = btrfs_mknod, 8865 .setxattr = btrfs_setxattr, 8866 .getxattr = btrfs_getxattr, 8867 .listxattr = btrfs_listxattr, 8868 .removexattr = btrfs_removexattr, 8869 .permission = btrfs_permission, 8870 .get_acl = btrfs_get_acl, 8871 .update_time = btrfs_update_time, 8872 }; 8873 static const struct inode_operations btrfs_dir_ro_inode_operations = { 8874 .lookup = btrfs_lookup, 8875 .permission = btrfs_permission, 8876 .get_acl = btrfs_get_acl, 8877 .update_time = btrfs_update_time, 8878 }; 8879 8880 static const struct file_operations btrfs_dir_file_operations = { 8881 .llseek = generic_file_llseek, 8882 .read = generic_read_dir, 8883 .iterate = btrfs_real_readdir, 8884 .unlocked_ioctl = btrfs_ioctl, 8885 #ifdef CONFIG_COMPAT 8886 .compat_ioctl = btrfs_ioctl, 8887 #endif 8888 .release = btrfs_release_file, 8889 .fsync = btrfs_sync_file, 8890 }; 8891 8892 static struct extent_io_ops btrfs_extent_io_ops = { 8893 .fill_delalloc = run_delalloc_range, 8894 .submit_bio_hook = btrfs_submit_bio_hook, 8895 .merge_bio_hook = btrfs_merge_bio_hook, 8896 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 8897 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 8898 .writepage_start_hook = btrfs_writepage_start_hook, 8899 .set_bit_hook = btrfs_set_bit_hook, 8900 .clear_bit_hook = btrfs_clear_bit_hook, 8901 .merge_extent_hook = btrfs_merge_extent_hook, 8902 .split_extent_hook = btrfs_split_extent_hook, 8903 }; 8904 8905 /* 8906 * btrfs doesn't support the bmap operation because swapfiles 8907 * use bmap to make a mapping of extents in the file. They assume 8908 * these extents won't change over the life of the file and they 8909 * use the bmap result to do IO directly to the drive. 8910 * 8911 * the btrfs bmap call would return logical addresses that aren't 8912 * suitable for IO and they also will change frequently as COW 8913 * operations happen. So, swapfile + btrfs == corruption. 8914 * 8915 * For now we're avoiding this by dropping bmap. 8916 */ 8917 static const struct address_space_operations btrfs_aops = { 8918 .readpage = btrfs_readpage, 8919 .writepage = btrfs_writepage, 8920 .writepages = btrfs_writepages, 8921 .readpages = btrfs_readpages, 8922 .direct_IO = btrfs_direct_IO, 8923 .invalidatepage = btrfs_invalidatepage, 8924 .releasepage = btrfs_releasepage, 8925 .set_page_dirty = btrfs_set_page_dirty, 8926 .error_remove_page = generic_error_remove_page, 8927 }; 8928 8929 static const struct address_space_operations btrfs_symlink_aops = { 8930 .readpage = btrfs_readpage, 8931 .writepage = btrfs_writepage, 8932 .invalidatepage = btrfs_invalidatepage, 8933 .releasepage = btrfs_releasepage, 8934 }; 8935 8936 static const struct inode_operations btrfs_file_inode_operations = { 8937 .getattr = btrfs_getattr, 8938 .setattr = btrfs_setattr, 8939 .setxattr = btrfs_setxattr, 8940 .getxattr = btrfs_getxattr, 8941 .listxattr = btrfs_listxattr, 8942 .removexattr = btrfs_removexattr, 8943 .permission = btrfs_permission, 8944 .fiemap = btrfs_fiemap, 8945 .get_acl = btrfs_get_acl, 8946 .update_time = btrfs_update_time, 8947 }; 8948 static const struct inode_operations btrfs_special_inode_operations = { 8949 .getattr = btrfs_getattr, 8950 .setattr = btrfs_setattr, 8951 .permission = btrfs_permission, 8952 .setxattr = btrfs_setxattr, 8953 .getxattr = btrfs_getxattr, 8954 .listxattr = btrfs_listxattr, 8955 .removexattr = btrfs_removexattr, 8956 .get_acl = btrfs_get_acl, 8957 .update_time = btrfs_update_time, 8958 }; 8959 static const struct inode_operations btrfs_symlink_inode_operations = { 8960 .readlink = generic_readlink, 8961 .follow_link = page_follow_link_light, 8962 .put_link = page_put_link, 8963 .getattr = btrfs_getattr, 8964 .setattr = btrfs_setattr, 8965 .permission = btrfs_permission, 8966 .setxattr = btrfs_setxattr, 8967 .getxattr = btrfs_getxattr, 8968 .listxattr = btrfs_listxattr, 8969 .removexattr = btrfs_removexattr, 8970 .get_acl = btrfs_get_acl, 8971 .update_time = btrfs_update_time, 8972 }; 8973 8974 const struct dentry_operations btrfs_dentry_operations = { 8975 .d_delete = btrfs_dentry_delete, 8976 .d_release = btrfs_dentry_release, 8977 }; 8978