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 "compat.h" 47 #include "ctree.h" 48 #include "disk-io.h" 49 #include "transaction.h" 50 #include "btrfs_inode.h" 51 #include "print-tree.h" 52 #include "ordered-data.h" 53 #include "xattr.h" 54 #include "tree-log.h" 55 #include "volumes.h" 56 #include "compression.h" 57 #include "locking.h" 58 #include "free-space-cache.h" 59 #include "inode-map.h" 60 #include "backref.h" 61 #include "hash.h" 62 63 struct btrfs_iget_args { 64 u64 ino; 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_root *root, struct inode *inode, 130 u64 start, size_t size, size_t compressed_size, 131 int compress_type, 132 struct page **compressed_pages) 133 { 134 struct btrfs_key key; 135 struct btrfs_path *path; 136 struct extent_buffer *leaf; 137 struct page *page = NULL; 138 char *kaddr; 139 unsigned long ptr; 140 struct btrfs_file_extent_item *ei; 141 int err = 0; 142 int ret; 143 size_t cur_size = size; 144 size_t datasize; 145 unsigned long offset; 146 147 if (compressed_size && compressed_pages) 148 cur_size = compressed_size; 149 150 path = btrfs_alloc_path(); 151 if (!path) 152 return -ENOMEM; 153 154 path->leave_spinning = 1; 155 156 key.objectid = btrfs_ino(inode); 157 key.offset = start; 158 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 159 datasize = btrfs_file_extent_calc_inline_size(cur_size); 160 161 inode_add_bytes(inode, size); 162 ret = btrfs_insert_empty_item(trans, root, path, &key, 163 datasize); 164 if (ret) { 165 err = ret; 166 goto fail; 167 } 168 leaf = path->nodes[0]; 169 ei = btrfs_item_ptr(leaf, path->slots[0], 170 struct btrfs_file_extent_item); 171 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 172 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 173 btrfs_set_file_extent_encryption(leaf, ei, 0); 174 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 175 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 176 ptr = btrfs_file_extent_inline_start(ei); 177 178 if (compress_type != BTRFS_COMPRESS_NONE) { 179 struct page *cpage; 180 int i = 0; 181 while (compressed_size > 0) { 182 cpage = compressed_pages[i]; 183 cur_size = min_t(unsigned long, compressed_size, 184 PAGE_CACHE_SIZE); 185 186 kaddr = kmap_atomic(cpage); 187 write_extent_buffer(leaf, kaddr, ptr, cur_size); 188 kunmap_atomic(kaddr); 189 190 i++; 191 ptr += cur_size; 192 compressed_size -= cur_size; 193 } 194 btrfs_set_file_extent_compression(leaf, ei, 195 compress_type); 196 } else { 197 page = find_get_page(inode->i_mapping, 198 start >> PAGE_CACHE_SHIFT); 199 btrfs_set_file_extent_compression(leaf, ei, 0); 200 kaddr = kmap_atomic(page); 201 offset = start & (PAGE_CACHE_SIZE - 1); 202 write_extent_buffer(leaf, kaddr + offset, ptr, size); 203 kunmap_atomic(kaddr); 204 page_cache_release(page); 205 } 206 btrfs_mark_buffer_dirty(leaf); 207 btrfs_free_path(path); 208 209 /* 210 * we're an inline extent, so nobody can 211 * extend the file past i_size without locking 212 * a page we already have locked. 213 * 214 * We must do any isize and inode updates 215 * before we unlock the pages. Otherwise we 216 * could end up racing with unlink. 217 */ 218 BTRFS_I(inode)->disk_i_size = inode->i_size; 219 ret = btrfs_update_inode(trans, root, inode); 220 221 return ret; 222 fail: 223 btrfs_free_path(path); 224 return err; 225 } 226 227 228 /* 229 * conditionally insert an inline extent into the file. This 230 * does the checks required to make sure the data is small enough 231 * to fit as an inline extent. 232 */ 233 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans, 234 struct btrfs_root *root, 235 struct inode *inode, u64 start, u64 end, 236 size_t compressed_size, int compress_type, 237 struct page **compressed_pages) 238 { 239 u64 isize = i_size_read(inode); 240 u64 actual_end = min(end + 1, isize); 241 u64 inline_len = actual_end - start; 242 u64 aligned_end = ALIGN(end, root->sectorsize); 243 u64 data_len = inline_len; 244 int ret; 245 246 if (compressed_size) 247 data_len = compressed_size; 248 249 if (start > 0 || 250 actual_end >= PAGE_CACHE_SIZE || 251 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || 252 (!compressed_size && 253 (actual_end & (root->sectorsize - 1)) == 0) || 254 end + 1 < isize || 255 data_len > root->fs_info->max_inline) { 256 return 1; 257 } 258 259 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1); 260 if (ret) 261 return ret; 262 263 if (isize > actual_end) 264 inline_len = min_t(u64, isize, actual_end); 265 ret = insert_inline_extent(trans, root, inode, start, 266 inline_len, compressed_size, 267 compress_type, compressed_pages); 268 if (ret && ret != -ENOSPC) { 269 btrfs_abort_transaction(trans, root, ret); 270 return ret; 271 } else if (ret == -ENOSPC) { 272 return 1; 273 } 274 275 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 276 btrfs_delalloc_release_metadata(inode, end + 1 - start); 277 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); 278 return 0; 279 } 280 281 struct async_extent { 282 u64 start; 283 u64 ram_size; 284 u64 compressed_size; 285 struct page **pages; 286 unsigned long nr_pages; 287 int compress_type; 288 struct list_head list; 289 }; 290 291 struct async_cow { 292 struct inode *inode; 293 struct btrfs_root *root; 294 struct page *locked_page; 295 u64 start; 296 u64 end; 297 struct list_head extents; 298 struct btrfs_work work; 299 }; 300 301 static noinline int add_async_extent(struct async_cow *cow, 302 u64 start, u64 ram_size, 303 u64 compressed_size, 304 struct page **pages, 305 unsigned long nr_pages, 306 int compress_type) 307 { 308 struct async_extent *async_extent; 309 310 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 311 BUG_ON(!async_extent); /* -ENOMEM */ 312 async_extent->start = start; 313 async_extent->ram_size = ram_size; 314 async_extent->compressed_size = compressed_size; 315 async_extent->pages = pages; 316 async_extent->nr_pages = nr_pages; 317 async_extent->compress_type = compress_type; 318 list_add_tail(&async_extent->list, &cow->extents); 319 return 0; 320 } 321 322 /* 323 * we create compressed extents in two phases. The first 324 * phase compresses a range of pages that have already been 325 * locked (both pages and state bits are locked). 326 * 327 * This is done inside an ordered work queue, and the compression 328 * is spread across many cpus. The actual IO submission is step 329 * two, and the ordered work queue takes care of making sure that 330 * happens in the same order things were put onto the queue by 331 * writepages and friends. 332 * 333 * If this code finds it can't get good compression, it puts an 334 * entry onto the work queue to write the uncompressed bytes. This 335 * makes sure that both compressed inodes and uncompressed inodes 336 * are written in the same order that the flusher thread sent them 337 * down. 338 */ 339 static noinline int compress_file_range(struct inode *inode, 340 struct page *locked_page, 341 u64 start, u64 end, 342 struct async_cow *async_cow, 343 int *num_added) 344 { 345 struct btrfs_root *root = BTRFS_I(inode)->root; 346 struct btrfs_trans_handle *trans; 347 u64 num_bytes; 348 u64 blocksize = root->sectorsize; 349 u64 actual_end; 350 u64 isize = i_size_read(inode); 351 int ret = 0; 352 struct page **pages = NULL; 353 unsigned long nr_pages; 354 unsigned long nr_pages_ret = 0; 355 unsigned long total_compressed = 0; 356 unsigned long total_in = 0; 357 unsigned long max_compressed = 128 * 1024; 358 unsigned long max_uncompressed = 128 * 1024; 359 int i; 360 int will_compress; 361 int compress_type = root->fs_info->compress_type; 362 int redirty = 0; 363 364 /* if this is a small write inside eof, kick off a defrag */ 365 if ((end - start + 1) < 16 * 1024 && 366 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 367 btrfs_add_inode_defrag(NULL, inode); 368 369 actual_end = min_t(u64, isize, end + 1); 370 again: 371 will_compress = 0; 372 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; 373 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); 374 375 /* 376 * we don't want to send crud past the end of i_size through 377 * compression, that's just a waste of CPU time. So, if the 378 * end of the file is before the start of our current 379 * requested range of bytes, we bail out to the uncompressed 380 * cleanup code that can deal with all of this. 381 * 382 * It isn't really the fastest way to fix things, but this is a 383 * very uncommon corner. 384 */ 385 if (actual_end <= start) 386 goto cleanup_and_bail_uncompressed; 387 388 total_compressed = actual_end - start; 389 390 /* we want to make sure that amount of ram required to uncompress 391 * an extent is reasonable, so we limit the total size in ram 392 * of a compressed extent to 128k. This is a crucial number 393 * because it also controls how easily we can spread reads across 394 * cpus for decompression. 395 * 396 * We also want to make sure the amount of IO required to do 397 * a random read is reasonably small, so we limit the size of 398 * a compressed extent to 128k. 399 */ 400 total_compressed = min(total_compressed, max_uncompressed); 401 num_bytes = ALIGN(end - start + 1, blocksize); 402 num_bytes = max(blocksize, num_bytes); 403 total_in = 0; 404 ret = 0; 405 406 /* 407 * we do compression for mount -o compress and when the 408 * inode has not been flagged as nocompress. This flag can 409 * change at any time if we discover bad compression ratios. 410 */ 411 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) && 412 (btrfs_test_opt(root, COMPRESS) || 413 (BTRFS_I(inode)->force_compress) || 414 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) { 415 WARN_ON(pages); 416 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); 417 if (!pages) { 418 /* just bail out to the uncompressed code */ 419 goto cont; 420 } 421 422 if (BTRFS_I(inode)->force_compress) 423 compress_type = BTRFS_I(inode)->force_compress; 424 425 /* 426 * we need to call clear_page_dirty_for_io on each 427 * page in the range. Otherwise applications with the file 428 * mmap'd can wander in and change the page contents while 429 * we are compressing them. 430 * 431 * If the compression fails for any reason, we set the pages 432 * dirty again later on. 433 */ 434 extent_range_clear_dirty_for_io(inode, start, end); 435 redirty = 1; 436 ret = btrfs_compress_pages(compress_type, 437 inode->i_mapping, start, 438 total_compressed, pages, 439 nr_pages, &nr_pages_ret, 440 &total_in, 441 &total_compressed, 442 max_compressed); 443 444 if (!ret) { 445 unsigned long offset = total_compressed & 446 (PAGE_CACHE_SIZE - 1); 447 struct page *page = pages[nr_pages_ret - 1]; 448 char *kaddr; 449 450 /* zero the tail end of the last page, we might be 451 * sending it down to disk 452 */ 453 if (offset) { 454 kaddr = kmap_atomic(page); 455 memset(kaddr + offset, 0, 456 PAGE_CACHE_SIZE - offset); 457 kunmap_atomic(kaddr); 458 } 459 will_compress = 1; 460 } 461 } 462 cont: 463 if (start == 0) { 464 trans = btrfs_join_transaction(root); 465 if (IS_ERR(trans)) { 466 ret = PTR_ERR(trans); 467 trans = NULL; 468 goto cleanup_and_out; 469 } 470 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 471 472 /* lets try to make an inline extent */ 473 if (ret || total_in < (actual_end - start)) { 474 /* we didn't compress the entire range, try 475 * to make an uncompressed inline extent. 476 */ 477 ret = cow_file_range_inline(trans, root, inode, 478 start, end, 0, 0, NULL); 479 } else { 480 /* try making a compressed inline extent */ 481 ret = cow_file_range_inline(trans, root, inode, 482 start, end, 483 total_compressed, 484 compress_type, pages); 485 } 486 if (ret <= 0) { 487 /* 488 * inline extent creation worked or returned error, 489 * we don't need to create any more async work items. 490 * Unlock and free up our temp pages. 491 */ 492 extent_clear_unlock_delalloc(inode, 493 &BTRFS_I(inode)->io_tree, 494 start, end, NULL, 495 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY | 496 EXTENT_CLEAR_DELALLOC | 497 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); 498 499 btrfs_end_transaction(trans, root); 500 goto free_pages_out; 501 } 502 btrfs_end_transaction(trans, root); 503 } 504 505 if (will_compress) { 506 /* 507 * we aren't doing an inline extent round the compressed size 508 * up to a block size boundary so the allocator does sane 509 * things 510 */ 511 total_compressed = ALIGN(total_compressed, blocksize); 512 513 /* 514 * one last check to make sure the compression is really a 515 * win, compare the page count read with the blocks on disk 516 */ 517 total_in = ALIGN(total_in, PAGE_CACHE_SIZE); 518 if (total_compressed >= total_in) { 519 will_compress = 0; 520 } else { 521 num_bytes = total_in; 522 } 523 } 524 if (!will_compress && pages) { 525 /* 526 * the compression code ran but failed to make things smaller, 527 * free any pages it allocated and our page pointer array 528 */ 529 for (i = 0; i < nr_pages_ret; i++) { 530 WARN_ON(pages[i]->mapping); 531 page_cache_release(pages[i]); 532 } 533 kfree(pages); 534 pages = NULL; 535 total_compressed = 0; 536 nr_pages_ret = 0; 537 538 /* flag the file so we don't compress in the future */ 539 if (!btrfs_test_opt(root, FORCE_COMPRESS) && 540 !(BTRFS_I(inode)->force_compress)) { 541 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 542 } 543 } 544 if (will_compress) { 545 *num_added += 1; 546 547 /* the async work queues will take care of doing actual 548 * allocation on disk for these compressed pages, 549 * and will submit them to the elevator. 550 */ 551 add_async_extent(async_cow, start, num_bytes, 552 total_compressed, pages, nr_pages_ret, 553 compress_type); 554 555 if (start + num_bytes < end) { 556 start += num_bytes; 557 pages = NULL; 558 cond_resched(); 559 goto again; 560 } 561 } else { 562 cleanup_and_bail_uncompressed: 563 /* 564 * No compression, but we still need to write the pages in 565 * the file we've been given so far. redirty the locked 566 * page if it corresponds to our extent and set things up 567 * for the async work queue to run cow_file_range to do 568 * the normal delalloc dance 569 */ 570 if (page_offset(locked_page) >= start && 571 page_offset(locked_page) <= end) { 572 __set_page_dirty_nobuffers(locked_page); 573 /* unlocked later on in the async handlers */ 574 } 575 if (redirty) 576 extent_range_redirty_for_io(inode, start, end); 577 add_async_extent(async_cow, start, end - start + 1, 578 0, NULL, 0, BTRFS_COMPRESS_NONE); 579 *num_added += 1; 580 } 581 582 out: 583 return ret; 584 585 free_pages_out: 586 for (i = 0; i < nr_pages_ret; i++) { 587 WARN_ON(pages[i]->mapping); 588 page_cache_release(pages[i]); 589 } 590 kfree(pages); 591 592 goto out; 593 594 cleanup_and_out: 595 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 596 start, end, NULL, 597 EXTENT_CLEAR_UNLOCK_PAGE | 598 EXTENT_CLEAR_DIRTY | 599 EXTENT_CLEAR_DELALLOC | 600 EXTENT_SET_WRITEBACK | 601 EXTENT_END_WRITEBACK); 602 if (!trans || IS_ERR(trans)) 603 btrfs_error(root->fs_info, ret, "Failed to join transaction"); 604 else 605 btrfs_abort_transaction(trans, root, ret); 606 goto free_pages_out; 607 } 608 609 /* 610 * phase two of compressed writeback. This is the ordered portion 611 * of the code, which only gets called in the order the work was 612 * queued. We walk all the async extents created by compress_file_range 613 * and send them down to the disk. 614 */ 615 static noinline int submit_compressed_extents(struct inode *inode, 616 struct async_cow *async_cow) 617 { 618 struct async_extent *async_extent; 619 u64 alloc_hint = 0; 620 struct btrfs_trans_handle *trans; 621 struct btrfs_key ins; 622 struct extent_map *em; 623 struct btrfs_root *root = BTRFS_I(inode)->root; 624 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 625 struct extent_io_tree *io_tree; 626 int ret = 0; 627 628 if (list_empty(&async_cow->extents)) 629 return 0; 630 631 again: 632 while (!list_empty(&async_cow->extents)) { 633 async_extent = list_entry(async_cow->extents.next, 634 struct async_extent, list); 635 list_del(&async_extent->list); 636 637 io_tree = &BTRFS_I(inode)->io_tree; 638 639 retry: 640 /* did the compression code fall back to uncompressed IO? */ 641 if (!async_extent->pages) { 642 int page_started = 0; 643 unsigned long nr_written = 0; 644 645 lock_extent(io_tree, async_extent->start, 646 async_extent->start + 647 async_extent->ram_size - 1); 648 649 /* allocate blocks */ 650 ret = cow_file_range(inode, async_cow->locked_page, 651 async_extent->start, 652 async_extent->start + 653 async_extent->ram_size - 1, 654 &page_started, &nr_written, 0); 655 656 /* JDM XXX */ 657 658 /* 659 * if page_started, cow_file_range inserted an 660 * inline extent and took care of all the unlocking 661 * and IO for us. Otherwise, we need to submit 662 * all those pages down to the drive. 663 */ 664 if (!page_started && !ret) 665 extent_write_locked_range(io_tree, 666 inode, async_extent->start, 667 async_extent->start + 668 async_extent->ram_size - 1, 669 btrfs_get_extent, 670 WB_SYNC_ALL); 671 else if (ret) 672 unlock_page(async_cow->locked_page); 673 kfree(async_extent); 674 cond_resched(); 675 continue; 676 } 677 678 lock_extent(io_tree, async_extent->start, 679 async_extent->start + async_extent->ram_size - 1); 680 681 trans = btrfs_join_transaction(root); 682 if (IS_ERR(trans)) { 683 ret = PTR_ERR(trans); 684 } else { 685 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 686 ret = btrfs_reserve_extent(trans, root, 687 async_extent->compressed_size, 688 async_extent->compressed_size, 689 0, alloc_hint, &ins, 1); 690 if (ret && ret != -ENOSPC) 691 btrfs_abort_transaction(trans, root, ret); 692 btrfs_end_transaction(trans, root); 693 } 694 695 if (ret) { 696 int i; 697 698 for (i = 0; i < async_extent->nr_pages; i++) { 699 WARN_ON(async_extent->pages[i]->mapping); 700 page_cache_release(async_extent->pages[i]); 701 } 702 kfree(async_extent->pages); 703 async_extent->nr_pages = 0; 704 async_extent->pages = NULL; 705 706 if (ret == -ENOSPC) { 707 unlock_extent(io_tree, async_extent->start, 708 async_extent->start + 709 async_extent->ram_size - 1); 710 goto retry; 711 } 712 goto out_free; 713 } 714 715 /* 716 * here we're doing allocation and writeback of the 717 * compressed pages 718 */ 719 btrfs_drop_extent_cache(inode, async_extent->start, 720 async_extent->start + 721 async_extent->ram_size - 1, 0); 722 723 em = alloc_extent_map(); 724 if (!em) { 725 ret = -ENOMEM; 726 goto out_free_reserve; 727 } 728 em->start = async_extent->start; 729 em->len = async_extent->ram_size; 730 em->orig_start = em->start; 731 em->mod_start = em->start; 732 em->mod_len = em->len; 733 734 em->block_start = ins.objectid; 735 em->block_len = ins.offset; 736 em->orig_block_len = ins.offset; 737 em->ram_bytes = async_extent->ram_size; 738 em->bdev = root->fs_info->fs_devices->latest_bdev; 739 em->compress_type = async_extent->compress_type; 740 set_bit(EXTENT_FLAG_PINNED, &em->flags); 741 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 742 em->generation = -1; 743 744 while (1) { 745 write_lock(&em_tree->lock); 746 ret = add_extent_mapping(em_tree, em, 1); 747 write_unlock(&em_tree->lock); 748 if (ret != -EEXIST) { 749 free_extent_map(em); 750 break; 751 } 752 btrfs_drop_extent_cache(inode, async_extent->start, 753 async_extent->start + 754 async_extent->ram_size - 1, 0); 755 } 756 757 if (ret) 758 goto out_free_reserve; 759 760 ret = btrfs_add_ordered_extent_compress(inode, 761 async_extent->start, 762 ins.objectid, 763 async_extent->ram_size, 764 ins.offset, 765 BTRFS_ORDERED_COMPRESSED, 766 async_extent->compress_type); 767 if (ret) 768 goto out_free_reserve; 769 770 /* 771 * clear dirty, set writeback and unlock the pages. 772 */ 773 extent_clear_unlock_delalloc(inode, 774 &BTRFS_I(inode)->io_tree, 775 async_extent->start, 776 async_extent->start + 777 async_extent->ram_size - 1, 778 NULL, EXTENT_CLEAR_UNLOCK_PAGE | 779 EXTENT_CLEAR_UNLOCK | 780 EXTENT_CLEAR_DELALLOC | 781 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK); 782 783 ret = btrfs_submit_compressed_write(inode, 784 async_extent->start, 785 async_extent->ram_size, 786 ins.objectid, 787 ins.offset, async_extent->pages, 788 async_extent->nr_pages); 789 alloc_hint = ins.objectid + ins.offset; 790 kfree(async_extent); 791 if (ret) 792 goto out; 793 cond_resched(); 794 } 795 ret = 0; 796 out: 797 return ret; 798 out_free_reserve: 799 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 800 out_free: 801 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 802 async_extent->start, 803 async_extent->start + 804 async_extent->ram_size - 1, 805 NULL, EXTENT_CLEAR_UNLOCK_PAGE | 806 EXTENT_CLEAR_UNLOCK | 807 EXTENT_CLEAR_DELALLOC | 808 EXTENT_CLEAR_DIRTY | 809 EXTENT_SET_WRITEBACK | 810 EXTENT_END_WRITEBACK); 811 kfree(async_extent); 812 goto again; 813 } 814 815 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 816 u64 num_bytes) 817 { 818 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 819 struct extent_map *em; 820 u64 alloc_hint = 0; 821 822 read_lock(&em_tree->lock); 823 em = search_extent_mapping(em_tree, start, num_bytes); 824 if (em) { 825 /* 826 * if block start isn't an actual block number then find the 827 * first block in this inode and use that as a hint. If that 828 * block is also bogus then just don't worry about it. 829 */ 830 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 831 free_extent_map(em); 832 em = search_extent_mapping(em_tree, 0, 0); 833 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 834 alloc_hint = em->block_start; 835 if (em) 836 free_extent_map(em); 837 } else { 838 alloc_hint = em->block_start; 839 free_extent_map(em); 840 } 841 } 842 read_unlock(&em_tree->lock); 843 844 return alloc_hint; 845 } 846 847 /* 848 * when extent_io.c finds a delayed allocation range in the file, 849 * the call backs end up in this code. The basic idea is to 850 * allocate extents on disk for the range, and create ordered data structs 851 * in ram to track those extents. 852 * 853 * locked_page is the page that writepage had locked already. We use 854 * it to make sure we don't do extra locks or unlocks. 855 * 856 * *page_started is set to one if we unlock locked_page and do everything 857 * required to start IO on it. It may be clean and already done with 858 * IO when we return. 859 */ 860 static noinline int __cow_file_range(struct btrfs_trans_handle *trans, 861 struct inode *inode, 862 struct btrfs_root *root, 863 struct page *locked_page, 864 u64 start, u64 end, int *page_started, 865 unsigned long *nr_written, 866 int unlock) 867 { 868 u64 alloc_hint = 0; 869 u64 num_bytes; 870 unsigned long ram_size; 871 u64 disk_num_bytes; 872 u64 cur_alloc_size; 873 u64 blocksize = root->sectorsize; 874 struct btrfs_key ins; 875 struct extent_map *em; 876 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 877 int ret = 0; 878 879 BUG_ON(btrfs_is_free_space_inode(inode)); 880 881 num_bytes = ALIGN(end - start + 1, blocksize); 882 num_bytes = max(blocksize, num_bytes); 883 disk_num_bytes = num_bytes; 884 885 /* if this is a small write inside eof, kick off defrag */ 886 if (num_bytes < 64 * 1024 && 887 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 888 btrfs_add_inode_defrag(trans, inode); 889 890 if (start == 0) { 891 /* lets try to make an inline extent */ 892 ret = cow_file_range_inline(trans, root, inode, 893 start, end, 0, 0, NULL); 894 if (ret == 0) { 895 extent_clear_unlock_delalloc(inode, 896 &BTRFS_I(inode)->io_tree, 897 start, end, NULL, 898 EXTENT_CLEAR_UNLOCK_PAGE | 899 EXTENT_CLEAR_UNLOCK | 900 EXTENT_CLEAR_DELALLOC | 901 EXTENT_CLEAR_DIRTY | 902 EXTENT_SET_WRITEBACK | 903 EXTENT_END_WRITEBACK); 904 905 *nr_written = *nr_written + 906 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; 907 *page_started = 1; 908 goto out; 909 } else if (ret < 0) { 910 btrfs_abort_transaction(trans, root, ret); 911 goto out_unlock; 912 } 913 } 914 915 BUG_ON(disk_num_bytes > 916 btrfs_super_total_bytes(root->fs_info->super_copy)); 917 918 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 919 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); 920 921 while (disk_num_bytes > 0) { 922 unsigned long op; 923 924 cur_alloc_size = disk_num_bytes; 925 ret = btrfs_reserve_extent(trans, root, cur_alloc_size, 926 root->sectorsize, 0, alloc_hint, 927 &ins, 1); 928 if (ret < 0) { 929 btrfs_abort_transaction(trans, root, ret); 930 goto out_unlock; 931 } 932 933 em = alloc_extent_map(); 934 if (!em) { 935 ret = -ENOMEM; 936 goto out_reserve; 937 } 938 em->start = start; 939 em->orig_start = em->start; 940 ram_size = ins.offset; 941 em->len = ins.offset; 942 em->mod_start = em->start; 943 em->mod_len = em->len; 944 945 em->block_start = ins.objectid; 946 em->block_len = ins.offset; 947 em->orig_block_len = ins.offset; 948 em->ram_bytes = ram_size; 949 em->bdev = root->fs_info->fs_devices->latest_bdev; 950 set_bit(EXTENT_FLAG_PINNED, &em->flags); 951 em->generation = -1; 952 953 while (1) { 954 write_lock(&em_tree->lock); 955 ret = add_extent_mapping(em_tree, em, 1); 956 write_unlock(&em_tree->lock); 957 if (ret != -EEXIST) { 958 free_extent_map(em); 959 break; 960 } 961 btrfs_drop_extent_cache(inode, start, 962 start + ram_size - 1, 0); 963 } 964 if (ret) 965 goto out_reserve; 966 967 cur_alloc_size = ins.offset; 968 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 969 ram_size, cur_alloc_size, 0); 970 if (ret) 971 goto out_reserve; 972 973 if (root->root_key.objectid == 974 BTRFS_DATA_RELOC_TREE_OBJECTID) { 975 ret = btrfs_reloc_clone_csums(inode, start, 976 cur_alloc_size); 977 if (ret) { 978 btrfs_abort_transaction(trans, root, ret); 979 goto out_reserve; 980 } 981 } 982 983 if (disk_num_bytes < cur_alloc_size) 984 break; 985 986 /* we're not doing compressed IO, don't unlock the first 987 * page (which the caller expects to stay locked), don't 988 * clear any dirty bits and don't set any writeback bits 989 * 990 * Do set the Private2 bit so we know this page was properly 991 * setup for writepage 992 */ 993 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0; 994 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | 995 EXTENT_SET_PRIVATE2; 996 997 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 998 start, start + ram_size - 1, 999 locked_page, op); 1000 disk_num_bytes -= cur_alloc_size; 1001 num_bytes -= cur_alloc_size; 1002 alloc_hint = ins.objectid + ins.offset; 1003 start += cur_alloc_size; 1004 } 1005 out: 1006 return ret; 1007 1008 out_reserve: 1009 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 1010 out_unlock: 1011 extent_clear_unlock_delalloc(inode, 1012 &BTRFS_I(inode)->io_tree, 1013 start, end, locked_page, 1014 EXTENT_CLEAR_UNLOCK_PAGE | 1015 EXTENT_CLEAR_UNLOCK | 1016 EXTENT_CLEAR_DELALLOC | 1017 EXTENT_CLEAR_DIRTY | 1018 EXTENT_SET_WRITEBACK | 1019 EXTENT_END_WRITEBACK); 1020 1021 goto out; 1022 } 1023 1024 static noinline int cow_file_range(struct inode *inode, 1025 struct page *locked_page, 1026 u64 start, u64 end, int *page_started, 1027 unsigned long *nr_written, 1028 int unlock) 1029 { 1030 struct btrfs_trans_handle *trans; 1031 struct btrfs_root *root = BTRFS_I(inode)->root; 1032 int ret; 1033 1034 trans = btrfs_join_transaction(root); 1035 if (IS_ERR(trans)) { 1036 extent_clear_unlock_delalloc(inode, 1037 &BTRFS_I(inode)->io_tree, 1038 start, end, locked_page, 1039 EXTENT_CLEAR_UNLOCK_PAGE | 1040 EXTENT_CLEAR_UNLOCK | 1041 EXTENT_CLEAR_DELALLOC | 1042 EXTENT_CLEAR_DIRTY | 1043 EXTENT_SET_WRITEBACK | 1044 EXTENT_END_WRITEBACK); 1045 return PTR_ERR(trans); 1046 } 1047 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1048 1049 ret = __cow_file_range(trans, inode, root, locked_page, start, end, 1050 page_started, nr_written, unlock); 1051 1052 btrfs_end_transaction(trans, root); 1053 1054 return ret; 1055 } 1056 1057 /* 1058 * work queue call back to started compression on a file and pages 1059 */ 1060 static noinline void async_cow_start(struct btrfs_work *work) 1061 { 1062 struct async_cow *async_cow; 1063 int num_added = 0; 1064 async_cow = container_of(work, struct async_cow, work); 1065 1066 compress_file_range(async_cow->inode, async_cow->locked_page, 1067 async_cow->start, async_cow->end, async_cow, 1068 &num_added); 1069 if (num_added == 0) { 1070 btrfs_add_delayed_iput(async_cow->inode); 1071 async_cow->inode = NULL; 1072 } 1073 } 1074 1075 /* 1076 * work queue call back to submit previously compressed pages 1077 */ 1078 static noinline void async_cow_submit(struct btrfs_work *work) 1079 { 1080 struct async_cow *async_cow; 1081 struct btrfs_root *root; 1082 unsigned long nr_pages; 1083 1084 async_cow = container_of(work, struct async_cow, work); 1085 1086 root = async_cow->root; 1087 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> 1088 PAGE_CACHE_SHIFT; 1089 1090 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 1091 5 * 1024 * 1024 && 1092 waitqueue_active(&root->fs_info->async_submit_wait)) 1093 wake_up(&root->fs_info->async_submit_wait); 1094 1095 if (async_cow->inode) 1096 submit_compressed_extents(async_cow->inode, async_cow); 1097 } 1098 1099 static noinline void async_cow_free(struct btrfs_work *work) 1100 { 1101 struct async_cow *async_cow; 1102 async_cow = container_of(work, struct async_cow, work); 1103 if (async_cow->inode) 1104 btrfs_add_delayed_iput(async_cow->inode); 1105 kfree(async_cow); 1106 } 1107 1108 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1109 u64 start, u64 end, int *page_started, 1110 unsigned long *nr_written) 1111 { 1112 struct async_cow *async_cow; 1113 struct btrfs_root *root = BTRFS_I(inode)->root; 1114 unsigned long nr_pages; 1115 u64 cur_end; 1116 int limit = 10 * 1024 * 1024; 1117 1118 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1119 1, 0, NULL, GFP_NOFS); 1120 while (start < end) { 1121 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1122 BUG_ON(!async_cow); /* -ENOMEM */ 1123 async_cow->inode = igrab(inode); 1124 async_cow->root = root; 1125 async_cow->locked_page = locked_page; 1126 async_cow->start = start; 1127 1128 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 1129 cur_end = end; 1130 else 1131 cur_end = min(end, start + 512 * 1024 - 1); 1132 1133 async_cow->end = cur_end; 1134 INIT_LIST_HEAD(&async_cow->extents); 1135 1136 async_cow->work.func = async_cow_start; 1137 async_cow->work.ordered_func = async_cow_submit; 1138 async_cow->work.ordered_free = async_cow_free; 1139 async_cow->work.flags = 0; 1140 1141 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> 1142 PAGE_CACHE_SHIFT; 1143 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); 1144 1145 btrfs_queue_worker(&root->fs_info->delalloc_workers, 1146 &async_cow->work); 1147 1148 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { 1149 wait_event(root->fs_info->async_submit_wait, 1150 (atomic_read(&root->fs_info->async_delalloc_pages) < 1151 limit)); 1152 } 1153 1154 while (atomic_read(&root->fs_info->async_submit_draining) && 1155 atomic_read(&root->fs_info->async_delalloc_pages)) { 1156 wait_event(root->fs_info->async_submit_wait, 1157 (atomic_read(&root->fs_info->async_delalloc_pages) == 1158 0)); 1159 } 1160 1161 *nr_written += nr_pages; 1162 start = cur_end + 1; 1163 } 1164 *page_started = 1; 1165 return 0; 1166 } 1167 1168 static noinline int csum_exist_in_range(struct btrfs_root *root, 1169 u64 bytenr, u64 num_bytes) 1170 { 1171 int ret; 1172 struct btrfs_ordered_sum *sums; 1173 LIST_HEAD(list); 1174 1175 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, 1176 bytenr + num_bytes - 1, &list, 0); 1177 if (ret == 0 && list_empty(&list)) 1178 return 0; 1179 1180 while (!list_empty(&list)) { 1181 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1182 list_del(&sums->list); 1183 kfree(sums); 1184 } 1185 return 1; 1186 } 1187 1188 /* 1189 * when nowcow writeback call back. This checks for snapshots or COW copies 1190 * of the extents that exist in the file, and COWs the file as required. 1191 * 1192 * If no cow copies or snapshots exist, we write directly to the existing 1193 * blocks on disk 1194 */ 1195 static noinline int run_delalloc_nocow(struct inode *inode, 1196 struct page *locked_page, 1197 u64 start, u64 end, int *page_started, int force, 1198 unsigned long *nr_written) 1199 { 1200 struct btrfs_root *root = BTRFS_I(inode)->root; 1201 struct btrfs_trans_handle *trans; 1202 struct extent_buffer *leaf; 1203 struct btrfs_path *path; 1204 struct btrfs_file_extent_item *fi; 1205 struct btrfs_key found_key; 1206 u64 cow_start; 1207 u64 cur_offset; 1208 u64 extent_end; 1209 u64 extent_offset; 1210 u64 disk_bytenr; 1211 u64 num_bytes; 1212 u64 disk_num_bytes; 1213 u64 ram_bytes; 1214 int extent_type; 1215 int ret, err; 1216 int type; 1217 int nocow; 1218 int check_prev = 1; 1219 bool nolock; 1220 u64 ino = btrfs_ino(inode); 1221 1222 path = btrfs_alloc_path(); 1223 if (!path) { 1224 extent_clear_unlock_delalloc(inode, 1225 &BTRFS_I(inode)->io_tree, 1226 start, end, locked_page, 1227 EXTENT_CLEAR_UNLOCK_PAGE | 1228 EXTENT_CLEAR_UNLOCK | 1229 EXTENT_CLEAR_DELALLOC | 1230 EXTENT_CLEAR_DIRTY | 1231 EXTENT_SET_WRITEBACK | 1232 EXTENT_END_WRITEBACK); 1233 return -ENOMEM; 1234 } 1235 1236 nolock = btrfs_is_free_space_inode(inode); 1237 1238 if (nolock) 1239 trans = btrfs_join_transaction_nolock(root); 1240 else 1241 trans = btrfs_join_transaction(root); 1242 1243 if (IS_ERR(trans)) { 1244 extent_clear_unlock_delalloc(inode, 1245 &BTRFS_I(inode)->io_tree, 1246 start, end, locked_page, 1247 EXTENT_CLEAR_UNLOCK_PAGE | 1248 EXTENT_CLEAR_UNLOCK | 1249 EXTENT_CLEAR_DELALLOC | 1250 EXTENT_CLEAR_DIRTY | 1251 EXTENT_SET_WRITEBACK | 1252 EXTENT_END_WRITEBACK); 1253 btrfs_free_path(path); 1254 return PTR_ERR(trans); 1255 } 1256 1257 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1258 1259 cow_start = (u64)-1; 1260 cur_offset = start; 1261 while (1) { 1262 ret = btrfs_lookup_file_extent(trans, root, path, ino, 1263 cur_offset, 0); 1264 if (ret < 0) { 1265 btrfs_abort_transaction(trans, root, ret); 1266 goto error; 1267 } 1268 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1269 leaf = path->nodes[0]; 1270 btrfs_item_key_to_cpu(leaf, &found_key, 1271 path->slots[0] - 1); 1272 if (found_key.objectid == ino && 1273 found_key.type == BTRFS_EXTENT_DATA_KEY) 1274 path->slots[0]--; 1275 } 1276 check_prev = 0; 1277 next_slot: 1278 leaf = path->nodes[0]; 1279 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1280 ret = btrfs_next_leaf(root, path); 1281 if (ret < 0) { 1282 btrfs_abort_transaction(trans, root, ret); 1283 goto error; 1284 } 1285 if (ret > 0) 1286 break; 1287 leaf = path->nodes[0]; 1288 } 1289 1290 nocow = 0; 1291 disk_bytenr = 0; 1292 num_bytes = 0; 1293 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1294 1295 if (found_key.objectid > ino || 1296 found_key.type > BTRFS_EXTENT_DATA_KEY || 1297 found_key.offset > end) 1298 break; 1299 1300 if (found_key.offset > cur_offset) { 1301 extent_end = found_key.offset; 1302 extent_type = 0; 1303 goto out_check; 1304 } 1305 1306 fi = btrfs_item_ptr(leaf, path->slots[0], 1307 struct btrfs_file_extent_item); 1308 extent_type = btrfs_file_extent_type(leaf, fi); 1309 1310 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1311 if (extent_type == BTRFS_FILE_EXTENT_REG || 1312 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1313 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1314 extent_offset = btrfs_file_extent_offset(leaf, fi); 1315 extent_end = found_key.offset + 1316 btrfs_file_extent_num_bytes(leaf, fi); 1317 disk_num_bytes = 1318 btrfs_file_extent_disk_num_bytes(leaf, fi); 1319 if (extent_end <= start) { 1320 path->slots[0]++; 1321 goto next_slot; 1322 } 1323 if (disk_bytenr == 0) 1324 goto out_check; 1325 if (btrfs_file_extent_compression(leaf, fi) || 1326 btrfs_file_extent_encryption(leaf, fi) || 1327 btrfs_file_extent_other_encoding(leaf, fi)) 1328 goto out_check; 1329 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1330 goto out_check; 1331 if (btrfs_extent_readonly(root, disk_bytenr)) 1332 goto out_check; 1333 if (btrfs_cross_ref_exist(trans, root, ino, 1334 found_key.offset - 1335 extent_offset, disk_bytenr)) 1336 goto out_check; 1337 disk_bytenr += extent_offset; 1338 disk_bytenr += cur_offset - found_key.offset; 1339 num_bytes = min(end + 1, extent_end) - cur_offset; 1340 /* 1341 * force cow if csum exists in the range. 1342 * this ensure that csum for a given extent are 1343 * either valid or do not exist. 1344 */ 1345 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 1346 goto out_check; 1347 nocow = 1; 1348 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1349 extent_end = found_key.offset + 1350 btrfs_file_extent_inline_len(leaf, fi); 1351 extent_end = ALIGN(extent_end, root->sectorsize); 1352 } else { 1353 BUG_ON(1); 1354 } 1355 out_check: 1356 if (extent_end <= start) { 1357 path->slots[0]++; 1358 goto next_slot; 1359 } 1360 if (!nocow) { 1361 if (cow_start == (u64)-1) 1362 cow_start = cur_offset; 1363 cur_offset = extent_end; 1364 if (cur_offset > end) 1365 break; 1366 path->slots[0]++; 1367 goto next_slot; 1368 } 1369 1370 btrfs_release_path(path); 1371 if (cow_start != (u64)-1) { 1372 ret = __cow_file_range(trans, inode, root, locked_page, 1373 cow_start, found_key.offset - 1, 1374 page_started, nr_written, 1); 1375 if (ret) { 1376 btrfs_abort_transaction(trans, root, ret); 1377 goto error; 1378 } 1379 cow_start = (u64)-1; 1380 } 1381 1382 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1383 struct extent_map *em; 1384 struct extent_map_tree *em_tree; 1385 em_tree = &BTRFS_I(inode)->extent_tree; 1386 em = alloc_extent_map(); 1387 BUG_ON(!em); /* -ENOMEM */ 1388 em->start = cur_offset; 1389 em->orig_start = found_key.offset - extent_offset; 1390 em->len = num_bytes; 1391 em->block_len = num_bytes; 1392 em->block_start = disk_bytenr; 1393 em->orig_block_len = disk_num_bytes; 1394 em->ram_bytes = ram_bytes; 1395 em->bdev = root->fs_info->fs_devices->latest_bdev; 1396 em->mod_start = em->start; 1397 em->mod_len = em->len; 1398 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1399 set_bit(EXTENT_FLAG_FILLING, &em->flags); 1400 em->generation = -1; 1401 while (1) { 1402 write_lock(&em_tree->lock); 1403 ret = add_extent_mapping(em_tree, em, 1); 1404 write_unlock(&em_tree->lock); 1405 if (ret != -EEXIST) { 1406 free_extent_map(em); 1407 break; 1408 } 1409 btrfs_drop_extent_cache(inode, em->start, 1410 em->start + em->len - 1, 0); 1411 } 1412 type = BTRFS_ORDERED_PREALLOC; 1413 } else { 1414 type = BTRFS_ORDERED_NOCOW; 1415 } 1416 1417 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1418 num_bytes, num_bytes, type); 1419 BUG_ON(ret); /* -ENOMEM */ 1420 1421 if (root->root_key.objectid == 1422 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1423 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1424 num_bytes); 1425 if (ret) { 1426 btrfs_abort_transaction(trans, root, ret); 1427 goto error; 1428 } 1429 } 1430 1431 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 1432 cur_offset, cur_offset + num_bytes - 1, 1433 locked_page, EXTENT_CLEAR_UNLOCK_PAGE | 1434 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | 1435 EXTENT_SET_PRIVATE2); 1436 cur_offset = extent_end; 1437 if (cur_offset > end) 1438 break; 1439 } 1440 btrfs_release_path(path); 1441 1442 if (cur_offset <= end && cow_start == (u64)-1) { 1443 cow_start = cur_offset; 1444 cur_offset = end; 1445 } 1446 1447 if (cow_start != (u64)-1) { 1448 ret = __cow_file_range(trans, inode, root, locked_page, 1449 cow_start, end, 1450 page_started, nr_written, 1); 1451 if (ret) { 1452 btrfs_abort_transaction(trans, root, ret); 1453 goto error; 1454 } 1455 } 1456 1457 error: 1458 err = btrfs_end_transaction(trans, root); 1459 if (!ret) 1460 ret = err; 1461 1462 if (ret && cur_offset < end) 1463 extent_clear_unlock_delalloc(inode, 1464 &BTRFS_I(inode)->io_tree, 1465 cur_offset, end, locked_page, 1466 EXTENT_CLEAR_UNLOCK_PAGE | 1467 EXTENT_CLEAR_UNLOCK | 1468 EXTENT_CLEAR_DELALLOC | 1469 EXTENT_CLEAR_DIRTY | 1470 EXTENT_SET_WRITEBACK | 1471 EXTENT_END_WRITEBACK); 1472 1473 btrfs_free_path(path); 1474 return ret; 1475 } 1476 1477 /* 1478 * extent_io.c call back to do delayed allocation processing 1479 */ 1480 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1481 u64 start, u64 end, int *page_started, 1482 unsigned long *nr_written) 1483 { 1484 int ret; 1485 struct btrfs_root *root = BTRFS_I(inode)->root; 1486 1487 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) { 1488 ret = run_delalloc_nocow(inode, locked_page, start, end, 1489 page_started, 1, nr_written); 1490 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) { 1491 ret = run_delalloc_nocow(inode, locked_page, start, end, 1492 page_started, 0, nr_written); 1493 } else if (!btrfs_test_opt(root, COMPRESS) && 1494 !(BTRFS_I(inode)->force_compress) && 1495 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) { 1496 ret = cow_file_range(inode, locked_page, start, end, 1497 page_started, nr_written, 1); 1498 } else { 1499 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1500 &BTRFS_I(inode)->runtime_flags); 1501 ret = cow_file_range_async(inode, locked_page, start, end, 1502 page_started, nr_written); 1503 } 1504 return ret; 1505 } 1506 1507 static void btrfs_split_extent_hook(struct inode *inode, 1508 struct extent_state *orig, u64 split) 1509 { 1510 /* not delalloc, ignore it */ 1511 if (!(orig->state & EXTENT_DELALLOC)) 1512 return; 1513 1514 spin_lock(&BTRFS_I(inode)->lock); 1515 BTRFS_I(inode)->outstanding_extents++; 1516 spin_unlock(&BTRFS_I(inode)->lock); 1517 } 1518 1519 /* 1520 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1521 * extents so we can keep track of new extents that are just merged onto old 1522 * extents, such as when we are doing sequential writes, so we can properly 1523 * account for the metadata space we'll need. 1524 */ 1525 static void btrfs_merge_extent_hook(struct inode *inode, 1526 struct extent_state *new, 1527 struct extent_state *other) 1528 { 1529 /* not delalloc, ignore it */ 1530 if (!(other->state & EXTENT_DELALLOC)) 1531 return; 1532 1533 spin_lock(&BTRFS_I(inode)->lock); 1534 BTRFS_I(inode)->outstanding_extents--; 1535 spin_unlock(&BTRFS_I(inode)->lock); 1536 } 1537 1538 static void btrfs_add_delalloc_inodes(struct btrfs_root *root, 1539 struct inode *inode) 1540 { 1541 spin_lock(&root->delalloc_lock); 1542 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1543 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1544 &root->delalloc_inodes); 1545 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1546 &BTRFS_I(inode)->runtime_flags); 1547 root->nr_delalloc_inodes++; 1548 if (root->nr_delalloc_inodes == 1) { 1549 spin_lock(&root->fs_info->delalloc_root_lock); 1550 BUG_ON(!list_empty(&root->delalloc_root)); 1551 list_add_tail(&root->delalloc_root, 1552 &root->fs_info->delalloc_roots); 1553 spin_unlock(&root->fs_info->delalloc_root_lock); 1554 } 1555 } 1556 spin_unlock(&root->delalloc_lock); 1557 } 1558 1559 static void btrfs_del_delalloc_inode(struct btrfs_root *root, 1560 struct inode *inode) 1561 { 1562 spin_lock(&root->delalloc_lock); 1563 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1564 list_del_init(&BTRFS_I(inode)->delalloc_inodes); 1565 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1566 &BTRFS_I(inode)->runtime_flags); 1567 root->nr_delalloc_inodes--; 1568 if (!root->nr_delalloc_inodes) { 1569 spin_lock(&root->fs_info->delalloc_root_lock); 1570 BUG_ON(list_empty(&root->delalloc_root)); 1571 list_del_init(&root->delalloc_root); 1572 spin_unlock(&root->fs_info->delalloc_root_lock); 1573 } 1574 } 1575 spin_unlock(&root->delalloc_lock); 1576 } 1577 1578 /* 1579 * extent_io.c set_bit_hook, used to track delayed allocation 1580 * bytes in this file, and to maintain the list of inodes that 1581 * have pending delalloc work to be done. 1582 */ 1583 static void btrfs_set_bit_hook(struct inode *inode, 1584 struct extent_state *state, unsigned long *bits) 1585 { 1586 1587 /* 1588 * set_bit and clear bit hooks normally require _irqsave/restore 1589 * but in this case, we are only testing for the DELALLOC 1590 * bit, which is only set or cleared with irqs on 1591 */ 1592 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1593 struct btrfs_root *root = BTRFS_I(inode)->root; 1594 u64 len = state->end + 1 - state->start; 1595 bool do_list = !btrfs_is_free_space_inode(inode); 1596 1597 if (*bits & EXTENT_FIRST_DELALLOC) { 1598 *bits &= ~EXTENT_FIRST_DELALLOC; 1599 } else { 1600 spin_lock(&BTRFS_I(inode)->lock); 1601 BTRFS_I(inode)->outstanding_extents++; 1602 spin_unlock(&BTRFS_I(inode)->lock); 1603 } 1604 1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, len, 1606 root->fs_info->delalloc_batch); 1607 spin_lock(&BTRFS_I(inode)->lock); 1608 BTRFS_I(inode)->delalloc_bytes += len; 1609 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1610 &BTRFS_I(inode)->runtime_flags)) 1611 btrfs_add_delalloc_inodes(root, inode); 1612 spin_unlock(&BTRFS_I(inode)->lock); 1613 } 1614 } 1615 1616 /* 1617 * extent_io.c clear_bit_hook, see set_bit_hook for why 1618 */ 1619 static void btrfs_clear_bit_hook(struct inode *inode, 1620 struct extent_state *state, 1621 unsigned long *bits) 1622 { 1623 /* 1624 * set_bit and clear bit hooks normally require _irqsave/restore 1625 * but in this case, we are only testing for the DELALLOC 1626 * bit, which is only set or cleared with irqs on 1627 */ 1628 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1629 struct btrfs_root *root = BTRFS_I(inode)->root; 1630 u64 len = state->end + 1 - state->start; 1631 bool do_list = !btrfs_is_free_space_inode(inode); 1632 1633 if (*bits & EXTENT_FIRST_DELALLOC) { 1634 *bits &= ~EXTENT_FIRST_DELALLOC; 1635 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1636 spin_lock(&BTRFS_I(inode)->lock); 1637 BTRFS_I(inode)->outstanding_extents--; 1638 spin_unlock(&BTRFS_I(inode)->lock); 1639 } 1640 1641 if (*bits & EXTENT_DO_ACCOUNTING) 1642 btrfs_delalloc_release_metadata(inode, len); 1643 1644 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1645 && do_list && !(state->state & EXTENT_NORESERVE)) 1646 btrfs_free_reserved_data_space(inode, len); 1647 1648 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, 1649 root->fs_info->delalloc_batch); 1650 spin_lock(&BTRFS_I(inode)->lock); 1651 BTRFS_I(inode)->delalloc_bytes -= len; 1652 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && 1653 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1654 &BTRFS_I(inode)->runtime_flags)) 1655 btrfs_del_delalloc_inode(root, inode); 1656 spin_unlock(&BTRFS_I(inode)->lock); 1657 } 1658 } 1659 1660 /* 1661 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1662 * we don't create bios that span stripes or chunks 1663 */ 1664 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, 1665 size_t size, struct bio *bio, 1666 unsigned long bio_flags) 1667 { 1668 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 1669 u64 logical = (u64)bio->bi_sector << 9; 1670 u64 length = 0; 1671 u64 map_length; 1672 int ret; 1673 1674 if (bio_flags & EXTENT_BIO_COMPRESSED) 1675 return 0; 1676 1677 length = bio->bi_size; 1678 map_length = length; 1679 ret = btrfs_map_block(root->fs_info, rw, logical, 1680 &map_length, NULL, 0); 1681 /* Will always return 0 with map_multi == NULL */ 1682 BUG_ON(ret < 0); 1683 if (map_length < length + size) 1684 return 1; 1685 return 0; 1686 } 1687 1688 /* 1689 * in order to insert checksums into the metadata in large chunks, 1690 * we wait until bio submission time. All the pages in the bio are 1691 * checksummed and sums are attached onto the ordered extent record. 1692 * 1693 * At IO completion time the cums attached on the ordered extent record 1694 * are inserted into the btree 1695 */ 1696 static int __btrfs_submit_bio_start(struct inode *inode, int rw, 1697 struct bio *bio, int mirror_num, 1698 unsigned long bio_flags, 1699 u64 bio_offset) 1700 { 1701 struct btrfs_root *root = BTRFS_I(inode)->root; 1702 int ret = 0; 1703 1704 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1705 BUG_ON(ret); /* -ENOMEM */ 1706 return 0; 1707 } 1708 1709 /* 1710 * in order to insert checksums into the metadata in large chunks, 1711 * we wait until bio submission time. All the pages in the bio are 1712 * checksummed and sums are attached onto the ordered extent record. 1713 * 1714 * At IO completion time the cums attached on the ordered extent record 1715 * are inserted into the btree 1716 */ 1717 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 1718 int mirror_num, unsigned long bio_flags, 1719 u64 bio_offset) 1720 { 1721 struct btrfs_root *root = BTRFS_I(inode)->root; 1722 int ret; 1723 1724 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); 1725 if (ret) 1726 bio_endio(bio, ret); 1727 return ret; 1728 } 1729 1730 /* 1731 * extent_io.c submission hook. This does the right thing for csum calculation 1732 * on write, or reading the csums from the tree before a read 1733 */ 1734 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 1735 int mirror_num, unsigned long bio_flags, 1736 u64 bio_offset) 1737 { 1738 struct btrfs_root *root = BTRFS_I(inode)->root; 1739 int ret = 0; 1740 int skip_sum; 1741 int metadata = 0; 1742 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1743 1744 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1745 1746 if (btrfs_is_free_space_inode(inode)) 1747 metadata = 2; 1748 1749 if (!(rw & REQ_WRITE)) { 1750 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); 1751 if (ret) 1752 goto out; 1753 1754 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1755 ret = btrfs_submit_compressed_read(inode, bio, 1756 mirror_num, 1757 bio_flags); 1758 goto out; 1759 } else if (!skip_sum) { 1760 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); 1761 if (ret) 1762 goto out; 1763 } 1764 goto mapit; 1765 } else if (async && !skip_sum) { 1766 /* csum items have already been cloned */ 1767 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1768 goto mapit; 1769 /* we're doing a write, do the async checksumming */ 1770 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 1771 inode, rw, bio, mirror_num, 1772 bio_flags, bio_offset, 1773 __btrfs_submit_bio_start, 1774 __btrfs_submit_bio_done); 1775 goto out; 1776 } else if (!skip_sum) { 1777 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1778 if (ret) 1779 goto out; 1780 } 1781 1782 mapit: 1783 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 1784 1785 out: 1786 if (ret < 0) 1787 bio_endio(bio, ret); 1788 return ret; 1789 } 1790 1791 /* 1792 * given a list of ordered sums record them in the inode. This happens 1793 * at IO completion time based on sums calculated at bio submission time. 1794 */ 1795 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1796 struct inode *inode, u64 file_offset, 1797 struct list_head *list) 1798 { 1799 struct btrfs_ordered_sum *sum; 1800 1801 list_for_each_entry(sum, list, list) { 1802 trans->adding_csums = 1; 1803 btrfs_csum_file_blocks(trans, 1804 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1805 trans->adding_csums = 0; 1806 } 1807 return 0; 1808 } 1809 1810 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1811 struct extent_state **cached_state) 1812 { 1813 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); 1814 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1815 cached_state, GFP_NOFS); 1816 } 1817 1818 /* see btrfs_writepage_start_hook for details on why this is required */ 1819 struct btrfs_writepage_fixup { 1820 struct page *page; 1821 struct btrfs_work work; 1822 }; 1823 1824 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1825 { 1826 struct btrfs_writepage_fixup *fixup; 1827 struct btrfs_ordered_extent *ordered; 1828 struct extent_state *cached_state = NULL; 1829 struct page *page; 1830 struct inode *inode; 1831 u64 page_start; 1832 u64 page_end; 1833 int ret; 1834 1835 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1836 page = fixup->page; 1837 again: 1838 lock_page(page); 1839 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1840 ClearPageChecked(page); 1841 goto out_page; 1842 } 1843 1844 inode = page->mapping->host; 1845 page_start = page_offset(page); 1846 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; 1847 1848 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, 1849 &cached_state); 1850 1851 /* already ordered? We're done */ 1852 if (PagePrivate2(page)) 1853 goto out; 1854 1855 ordered = btrfs_lookup_ordered_extent(inode, page_start); 1856 if (ordered) { 1857 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 1858 page_end, &cached_state, GFP_NOFS); 1859 unlock_page(page); 1860 btrfs_start_ordered_extent(inode, ordered, 1); 1861 btrfs_put_ordered_extent(ordered); 1862 goto again; 1863 } 1864 1865 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 1866 if (ret) { 1867 mapping_set_error(page->mapping, ret); 1868 end_extent_writepage(page, ret, page_start, page_end); 1869 ClearPageChecked(page); 1870 goto out; 1871 } 1872 1873 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); 1874 ClearPageChecked(page); 1875 set_page_dirty(page); 1876 out: 1877 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 1878 &cached_state, GFP_NOFS); 1879 out_page: 1880 unlock_page(page); 1881 page_cache_release(page); 1882 kfree(fixup); 1883 } 1884 1885 /* 1886 * There are a few paths in the higher layers of the kernel that directly 1887 * set the page dirty bit without asking the filesystem if it is a 1888 * good idea. This causes problems because we want to make sure COW 1889 * properly happens and the data=ordered rules are followed. 1890 * 1891 * In our case any range that doesn't have the ORDERED bit set 1892 * hasn't been properly setup for IO. We kick off an async process 1893 * to fix it up. The async helper will wait for ordered extents, set 1894 * the delalloc bit and make it safe to write the page. 1895 */ 1896 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 1897 { 1898 struct inode *inode = page->mapping->host; 1899 struct btrfs_writepage_fixup *fixup; 1900 struct btrfs_root *root = BTRFS_I(inode)->root; 1901 1902 /* this page is properly in the ordered list */ 1903 if (TestClearPagePrivate2(page)) 1904 return 0; 1905 1906 if (PageChecked(page)) 1907 return -EAGAIN; 1908 1909 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 1910 if (!fixup) 1911 return -EAGAIN; 1912 1913 SetPageChecked(page); 1914 page_cache_get(page); 1915 fixup->work.func = btrfs_writepage_fixup_worker; 1916 fixup->page = page; 1917 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work); 1918 return -EBUSY; 1919 } 1920 1921 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 1922 struct inode *inode, u64 file_pos, 1923 u64 disk_bytenr, u64 disk_num_bytes, 1924 u64 num_bytes, u64 ram_bytes, 1925 u8 compression, u8 encryption, 1926 u16 other_encoding, int extent_type) 1927 { 1928 struct btrfs_root *root = BTRFS_I(inode)->root; 1929 struct btrfs_file_extent_item *fi; 1930 struct btrfs_path *path; 1931 struct extent_buffer *leaf; 1932 struct btrfs_key ins; 1933 int ret; 1934 1935 path = btrfs_alloc_path(); 1936 if (!path) 1937 return -ENOMEM; 1938 1939 path->leave_spinning = 1; 1940 1941 /* 1942 * we may be replacing one extent in the tree with another. 1943 * The new extent is pinned in the extent map, and we don't want 1944 * to drop it from the cache until it is completely in the btree. 1945 * 1946 * So, tell btrfs_drop_extents to leave this extent in the cache. 1947 * the caller is expected to unpin it and allow it to be merged 1948 * with the others. 1949 */ 1950 ret = btrfs_drop_extents(trans, root, inode, file_pos, 1951 file_pos + num_bytes, 0); 1952 if (ret) 1953 goto out; 1954 1955 ins.objectid = btrfs_ino(inode); 1956 ins.offset = file_pos; 1957 ins.type = BTRFS_EXTENT_DATA_KEY; 1958 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi)); 1959 if (ret) 1960 goto out; 1961 leaf = path->nodes[0]; 1962 fi = btrfs_item_ptr(leaf, path->slots[0], 1963 struct btrfs_file_extent_item); 1964 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1965 btrfs_set_file_extent_type(leaf, fi, extent_type); 1966 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 1967 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 1968 btrfs_set_file_extent_offset(leaf, fi, 0); 1969 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 1970 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 1971 btrfs_set_file_extent_compression(leaf, fi, compression); 1972 btrfs_set_file_extent_encryption(leaf, fi, encryption); 1973 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 1974 1975 btrfs_mark_buffer_dirty(leaf); 1976 btrfs_release_path(path); 1977 1978 inode_add_bytes(inode, num_bytes); 1979 1980 ins.objectid = disk_bytenr; 1981 ins.offset = disk_num_bytes; 1982 ins.type = BTRFS_EXTENT_ITEM_KEY; 1983 ret = btrfs_alloc_reserved_file_extent(trans, root, 1984 root->root_key.objectid, 1985 btrfs_ino(inode), file_pos, &ins); 1986 out: 1987 btrfs_free_path(path); 1988 1989 return ret; 1990 } 1991 1992 /* snapshot-aware defrag */ 1993 struct sa_defrag_extent_backref { 1994 struct rb_node node; 1995 struct old_sa_defrag_extent *old; 1996 u64 root_id; 1997 u64 inum; 1998 u64 file_pos; 1999 u64 extent_offset; 2000 u64 num_bytes; 2001 u64 generation; 2002 }; 2003 2004 struct old_sa_defrag_extent { 2005 struct list_head list; 2006 struct new_sa_defrag_extent *new; 2007 2008 u64 extent_offset; 2009 u64 bytenr; 2010 u64 offset; 2011 u64 len; 2012 int count; 2013 }; 2014 2015 struct new_sa_defrag_extent { 2016 struct rb_root root; 2017 struct list_head head; 2018 struct btrfs_path *path; 2019 struct inode *inode; 2020 u64 file_pos; 2021 u64 len; 2022 u64 bytenr; 2023 u64 disk_len; 2024 u8 compress_type; 2025 }; 2026 2027 static int backref_comp(struct sa_defrag_extent_backref *b1, 2028 struct sa_defrag_extent_backref *b2) 2029 { 2030 if (b1->root_id < b2->root_id) 2031 return -1; 2032 else if (b1->root_id > b2->root_id) 2033 return 1; 2034 2035 if (b1->inum < b2->inum) 2036 return -1; 2037 else if (b1->inum > b2->inum) 2038 return 1; 2039 2040 if (b1->file_pos < b2->file_pos) 2041 return -1; 2042 else if (b1->file_pos > b2->file_pos) 2043 return 1; 2044 2045 /* 2046 * [------------------------------] ===> (a range of space) 2047 * |<--->| |<---->| =============> (fs/file tree A) 2048 * |<---------------------------->| ===> (fs/file tree B) 2049 * 2050 * A range of space can refer to two file extents in one tree while 2051 * refer to only one file extent in another tree. 2052 * 2053 * So we may process a disk offset more than one time(two extents in A) 2054 * and locate at the same extent(one extent in B), then insert two same 2055 * backrefs(both refer to the extent in B). 2056 */ 2057 return 0; 2058 } 2059 2060 static void backref_insert(struct rb_root *root, 2061 struct sa_defrag_extent_backref *backref) 2062 { 2063 struct rb_node **p = &root->rb_node; 2064 struct rb_node *parent = NULL; 2065 struct sa_defrag_extent_backref *entry; 2066 int ret; 2067 2068 while (*p) { 2069 parent = *p; 2070 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2071 2072 ret = backref_comp(backref, entry); 2073 if (ret < 0) 2074 p = &(*p)->rb_left; 2075 else 2076 p = &(*p)->rb_right; 2077 } 2078 2079 rb_link_node(&backref->node, parent, p); 2080 rb_insert_color(&backref->node, root); 2081 } 2082 2083 /* 2084 * Note the backref might has changed, and in this case we just return 0. 2085 */ 2086 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2087 void *ctx) 2088 { 2089 struct btrfs_file_extent_item *extent; 2090 struct btrfs_fs_info *fs_info; 2091 struct old_sa_defrag_extent *old = ctx; 2092 struct new_sa_defrag_extent *new = old->new; 2093 struct btrfs_path *path = new->path; 2094 struct btrfs_key key; 2095 struct btrfs_root *root; 2096 struct sa_defrag_extent_backref *backref; 2097 struct extent_buffer *leaf; 2098 struct inode *inode = new->inode; 2099 int slot; 2100 int ret; 2101 u64 extent_offset; 2102 u64 num_bytes; 2103 2104 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2105 inum == btrfs_ino(inode)) 2106 return 0; 2107 2108 key.objectid = root_id; 2109 key.type = BTRFS_ROOT_ITEM_KEY; 2110 key.offset = (u64)-1; 2111 2112 fs_info = BTRFS_I(inode)->root->fs_info; 2113 root = btrfs_read_fs_root_no_name(fs_info, &key); 2114 if (IS_ERR(root)) { 2115 if (PTR_ERR(root) == -ENOENT) 2116 return 0; 2117 WARN_ON(1); 2118 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", 2119 inum, offset, root_id); 2120 return PTR_ERR(root); 2121 } 2122 2123 key.objectid = inum; 2124 key.type = BTRFS_EXTENT_DATA_KEY; 2125 if (offset > (u64)-1 << 32) 2126 key.offset = 0; 2127 else 2128 key.offset = offset; 2129 2130 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2131 if (ret < 0) { 2132 WARN_ON(1); 2133 return ret; 2134 } 2135 2136 while (1) { 2137 cond_resched(); 2138 2139 leaf = path->nodes[0]; 2140 slot = path->slots[0]; 2141 2142 if (slot >= btrfs_header_nritems(leaf)) { 2143 ret = btrfs_next_leaf(root, path); 2144 if (ret < 0) { 2145 goto out; 2146 } else if (ret > 0) { 2147 ret = 0; 2148 goto out; 2149 } 2150 continue; 2151 } 2152 2153 path->slots[0]++; 2154 2155 btrfs_item_key_to_cpu(leaf, &key, slot); 2156 2157 if (key.objectid > inum) 2158 goto out; 2159 2160 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2161 continue; 2162 2163 extent = btrfs_item_ptr(leaf, slot, 2164 struct btrfs_file_extent_item); 2165 2166 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2167 continue; 2168 2169 extent_offset = btrfs_file_extent_offset(leaf, extent); 2170 if (key.offset - extent_offset != offset) 2171 continue; 2172 2173 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2174 if (extent_offset >= old->extent_offset + old->offset + 2175 old->len || extent_offset + num_bytes <= 2176 old->extent_offset + old->offset) 2177 continue; 2178 2179 break; 2180 } 2181 2182 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2183 if (!backref) { 2184 ret = -ENOENT; 2185 goto out; 2186 } 2187 2188 backref->root_id = root_id; 2189 backref->inum = inum; 2190 backref->file_pos = offset + extent_offset; 2191 backref->num_bytes = num_bytes; 2192 backref->extent_offset = extent_offset; 2193 backref->generation = btrfs_file_extent_generation(leaf, extent); 2194 backref->old = old; 2195 backref_insert(&new->root, backref); 2196 old->count++; 2197 out: 2198 btrfs_release_path(path); 2199 WARN_ON(ret); 2200 return ret; 2201 } 2202 2203 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2204 struct new_sa_defrag_extent *new) 2205 { 2206 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; 2207 struct old_sa_defrag_extent *old, *tmp; 2208 int ret; 2209 2210 new->path = path; 2211 2212 list_for_each_entry_safe(old, tmp, &new->head, list) { 2213 ret = iterate_inodes_from_logical(old->bytenr, fs_info, 2214 path, record_one_backref, 2215 old); 2216 BUG_ON(ret < 0 && ret != -ENOENT); 2217 2218 /* no backref to be processed for this extent */ 2219 if (!old->count) { 2220 list_del(&old->list); 2221 kfree(old); 2222 } 2223 } 2224 2225 if (list_empty(&new->head)) 2226 return false; 2227 2228 return true; 2229 } 2230 2231 static int relink_is_mergable(struct extent_buffer *leaf, 2232 struct btrfs_file_extent_item *fi, 2233 u64 disk_bytenr) 2234 { 2235 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr) 2236 return 0; 2237 2238 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2239 return 0; 2240 2241 if (btrfs_file_extent_compression(leaf, fi) || 2242 btrfs_file_extent_encryption(leaf, fi) || 2243 btrfs_file_extent_other_encoding(leaf, fi)) 2244 return 0; 2245 2246 return 1; 2247 } 2248 2249 /* 2250 * Note the backref might has changed, and in this case we just return 0. 2251 */ 2252 static noinline int relink_extent_backref(struct btrfs_path *path, 2253 struct sa_defrag_extent_backref *prev, 2254 struct sa_defrag_extent_backref *backref) 2255 { 2256 struct btrfs_file_extent_item *extent; 2257 struct btrfs_file_extent_item *item; 2258 struct btrfs_ordered_extent *ordered; 2259 struct btrfs_trans_handle *trans; 2260 struct btrfs_fs_info *fs_info; 2261 struct btrfs_root *root; 2262 struct btrfs_key key; 2263 struct extent_buffer *leaf; 2264 struct old_sa_defrag_extent *old = backref->old; 2265 struct new_sa_defrag_extent *new = old->new; 2266 struct inode *src_inode = new->inode; 2267 struct inode *inode; 2268 struct extent_state *cached = NULL; 2269 int ret = 0; 2270 u64 start; 2271 u64 len; 2272 u64 lock_start; 2273 u64 lock_end; 2274 bool merge = false; 2275 int index; 2276 2277 if (prev && prev->root_id == backref->root_id && 2278 prev->inum == backref->inum && 2279 prev->file_pos + prev->num_bytes == backref->file_pos) 2280 merge = true; 2281 2282 /* step 1: get root */ 2283 key.objectid = backref->root_id; 2284 key.type = BTRFS_ROOT_ITEM_KEY; 2285 key.offset = (u64)-1; 2286 2287 fs_info = BTRFS_I(src_inode)->root->fs_info; 2288 index = srcu_read_lock(&fs_info->subvol_srcu); 2289 2290 root = btrfs_read_fs_root_no_name(fs_info, &key); 2291 if (IS_ERR(root)) { 2292 srcu_read_unlock(&fs_info->subvol_srcu, index); 2293 if (PTR_ERR(root) == -ENOENT) 2294 return 0; 2295 return PTR_ERR(root); 2296 } 2297 2298 /* step 2: get inode */ 2299 key.objectid = backref->inum; 2300 key.type = BTRFS_INODE_ITEM_KEY; 2301 key.offset = 0; 2302 2303 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2304 if (IS_ERR(inode)) { 2305 srcu_read_unlock(&fs_info->subvol_srcu, index); 2306 return 0; 2307 } 2308 2309 srcu_read_unlock(&fs_info->subvol_srcu, index); 2310 2311 /* step 3: relink backref */ 2312 lock_start = backref->file_pos; 2313 lock_end = backref->file_pos + backref->num_bytes - 1; 2314 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2315 0, &cached); 2316 2317 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2318 if (ordered) { 2319 btrfs_put_ordered_extent(ordered); 2320 goto out_unlock; 2321 } 2322 2323 trans = btrfs_join_transaction(root); 2324 if (IS_ERR(trans)) { 2325 ret = PTR_ERR(trans); 2326 goto out_unlock; 2327 } 2328 2329 key.objectid = backref->inum; 2330 key.type = BTRFS_EXTENT_DATA_KEY; 2331 key.offset = backref->file_pos; 2332 2333 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2334 if (ret < 0) { 2335 goto out_free_path; 2336 } else if (ret > 0) { 2337 ret = 0; 2338 goto out_free_path; 2339 } 2340 2341 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2342 struct btrfs_file_extent_item); 2343 2344 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2345 backref->generation) 2346 goto out_free_path; 2347 2348 btrfs_release_path(path); 2349 2350 start = backref->file_pos; 2351 if (backref->extent_offset < old->extent_offset + old->offset) 2352 start += old->extent_offset + old->offset - 2353 backref->extent_offset; 2354 2355 len = min(backref->extent_offset + backref->num_bytes, 2356 old->extent_offset + old->offset + old->len); 2357 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2358 2359 ret = btrfs_drop_extents(trans, root, inode, start, 2360 start + len, 1); 2361 if (ret) 2362 goto out_free_path; 2363 again: 2364 key.objectid = btrfs_ino(inode); 2365 key.type = BTRFS_EXTENT_DATA_KEY; 2366 key.offset = start; 2367 2368 path->leave_spinning = 1; 2369 if (merge) { 2370 struct btrfs_file_extent_item *fi; 2371 u64 extent_len; 2372 struct btrfs_key found_key; 2373 2374 ret = btrfs_search_slot(trans, root, &key, path, 1, 1); 2375 if (ret < 0) 2376 goto out_free_path; 2377 2378 path->slots[0]--; 2379 leaf = path->nodes[0]; 2380 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2381 2382 fi = btrfs_item_ptr(leaf, path->slots[0], 2383 struct btrfs_file_extent_item); 2384 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2385 2386 if (relink_is_mergable(leaf, fi, new->bytenr) && 2387 extent_len + found_key.offset == start) { 2388 btrfs_set_file_extent_num_bytes(leaf, fi, 2389 extent_len + len); 2390 btrfs_mark_buffer_dirty(leaf); 2391 inode_add_bytes(inode, len); 2392 2393 ret = 1; 2394 goto out_free_path; 2395 } else { 2396 merge = false; 2397 btrfs_release_path(path); 2398 goto again; 2399 } 2400 } 2401 2402 ret = btrfs_insert_empty_item(trans, root, path, &key, 2403 sizeof(*extent)); 2404 if (ret) { 2405 btrfs_abort_transaction(trans, root, ret); 2406 goto out_free_path; 2407 } 2408 2409 leaf = path->nodes[0]; 2410 item = btrfs_item_ptr(leaf, path->slots[0], 2411 struct btrfs_file_extent_item); 2412 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2413 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2414 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2415 btrfs_set_file_extent_num_bytes(leaf, item, len); 2416 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2417 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2418 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2419 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2420 btrfs_set_file_extent_encryption(leaf, item, 0); 2421 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2422 2423 btrfs_mark_buffer_dirty(leaf); 2424 inode_add_bytes(inode, len); 2425 btrfs_release_path(path); 2426 2427 ret = btrfs_inc_extent_ref(trans, root, new->bytenr, 2428 new->disk_len, 0, 2429 backref->root_id, backref->inum, 2430 new->file_pos, 0); /* start - extent_offset */ 2431 if (ret) { 2432 btrfs_abort_transaction(trans, root, ret); 2433 goto out_free_path; 2434 } 2435 2436 ret = 1; 2437 out_free_path: 2438 btrfs_release_path(path); 2439 path->leave_spinning = 0; 2440 btrfs_end_transaction(trans, root); 2441 out_unlock: 2442 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2443 &cached, GFP_NOFS); 2444 iput(inode); 2445 return ret; 2446 } 2447 2448 static void relink_file_extents(struct new_sa_defrag_extent *new) 2449 { 2450 struct btrfs_path *path; 2451 struct old_sa_defrag_extent *old, *tmp; 2452 struct sa_defrag_extent_backref *backref; 2453 struct sa_defrag_extent_backref *prev = NULL; 2454 struct inode *inode; 2455 struct btrfs_root *root; 2456 struct rb_node *node; 2457 int ret; 2458 2459 inode = new->inode; 2460 root = BTRFS_I(inode)->root; 2461 2462 path = btrfs_alloc_path(); 2463 if (!path) 2464 return; 2465 2466 if (!record_extent_backrefs(path, new)) { 2467 btrfs_free_path(path); 2468 goto out; 2469 } 2470 btrfs_release_path(path); 2471 2472 while (1) { 2473 node = rb_first(&new->root); 2474 if (!node) 2475 break; 2476 rb_erase(node, &new->root); 2477 2478 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2479 2480 ret = relink_extent_backref(path, prev, backref); 2481 WARN_ON(ret < 0); 2482 2483 kfree(prev); 2484 2485 if (ret == 1) 2486 prev = backref; 2487 else 2488 prev = NULL; 2489 cond_resched(); 2490 } 2491 kfree(prev); 2492 2493 btrfs_free_path(path); 2494 2495 list_for_each_entry_safe(old, tmp, &new->head, list) { 2496 list_del(&old->list); 2497 kfree(old); 2498 } 2499 out: 2500 atomic_dec(&root->fs_info->defrag_running); 2501 wake_up(&root->fs_info->transaction_wait); 2502 2503 kfree(new); 2504 } 2505 2506 static struct new_sa_defrag_extent * 2507 record_old_file_extents(struct inode *inode, 2508 struct btrfs_ordered_extent *ordered) 2509 { 2510 struct btrfs_root *root = BTRFS_I(inode)->root; 2511 struct btrfs_path *path; 2512 struct btrfs_key key; 2513 struct old_sa_defrag_extent *old, *tmp; 2514 struct new_sa_defrag_extent *new; 2515 int ret; 2516 2517 new = kmalloc(sizeof(*new), GFP_NOFS); 2518 if (!new) 2519 return NULL; 2520 2521 new->inode = inode; 2522 new->file_pos = ordered->file_offset; 2523 new->len = ordered->len; 2524 new->bytenr = ordered->start; 2525 new->disk_len = ordered->disk_len; 2526 new->compress_type = ordered->compress_type; 2527 new->root = RB_ROOT; 2528 INIT_LIST_HEAD(&new->head); 2529 2530 path = btrfs_alloc_path(); 2531 if (!path) 2532 goto out_kfree; 2533 2534 key.objectid = btrfs_ino(inode); 2535 key.type = BTRFS_EXTENT_DATA_KEY; 2536 key.offset = new->file_pos; 2537 2538 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2539 if (ret < 0) 2540 goto out_free_path; 2541 if (ret > 0 && path->slots[0] > 0) 2542 path->slots[0]--; 2543 2544 /* find out all the old extents for the file range */ 2545 while (1) { 2546 struct btrfs_file_extent_item *extent; 2547 struct extent_buffer *l; 2548 int slot; 2549 u64 num_bytes; 2550 u64 offset; 2551 u64 end; 2552 u64 disk_bytenr; 2553 u64 extent_offset; 2554 2555 l = path->nodes[0]; 2556 slot = path->slots[0]; 2557 2558 if (slot >= btrfs_header_nritems(l)) { 2559 ret = btrfs_next_leaf(root, path); 2560 if (ret < 0) 2561 goto out_free_list; 2562 else if (ret > 0) 2563 break; 2564 continue; 2565 } 2566 2567 btrfs_item_key_to_cpu(l, &key, slot); 2568 2569 if (key.objectid != btrfs_ino(inode)) 2570 break; 2571 if (key.type != BTRFS_EXTENT_DATA_KEY) 2572 break; 2573 if (key.offset >= new->file_pos + new->len) 2574 break; 2575 2576 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2577 2578 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2579 if (key.offset + num_bytes < new->file_pos) 2580 goto next; 2581 2582 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2583 if (!disk_bytenr) 2584 goto next; 2585 2586 extent_offset = btrfs_file_extent_offset(l, extent); 2587 2588 old = kmalloc(sizeof(*old), GFP_NOFS); 2589 if (!old) 2590 goto out_free_list; 2591 2592 offset = max(new->file_pos, key.offset); 2593 end = min(new->file_pos + new->len, key.offset + num_bytes); 2594 2595 old->bytenr = disk_bytenr; 2596 old->extent_offset = extent_offset; 2597 old->offset = offset - key.offset; 2598 old->len = end - offset; 2599 old->new = new; 2600 old->count = 0; 2601 list_add_tail(&old->list, &new->head); 2602 next: 2603 path->slots[0]++; 2604 cond_resched(); 2605 } 2606 2607 btrfs_free_path(path); 2608 atomic_inc(&root->fs_info->defrag_running); 2609 2610 return new; 2611 2612 out_free_list: 2613 list_for_each_entry_safe(old, tmp, &new->head, list) { 2614 list_del(&old->list); 2615 kfree(old); 2616 } 2617 out_free_path: 2618 btrfs_free_path(path); 2619 out_kfree: 2620 kfree(new); 2621 return NULL; 2622 } 2623 2624 /* 2625 * helper function for btrfs_finish_ordered_io, this 2626 * just reads in some of the csum leaves to prime them into ram 2627 * before we start the transaction. It limits the amount of btree 2628 * reads required while inside the transaction. 2629 */ 2630 /* as ordered data IO finishes, this gets called so we can finish 2631 * an ordered extent if the range of bytes in the file it covers are 2632 * fully written. 2633 */ 2634 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2635 { 2636 struct inode *inode = ordered_extent->inode; 2637 struct btrfs_root *root = BTRFS_I(inode)->root; 2638 struct btrfs_trans_handle *trans = NULL; 2639 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2640 struct extent_state *cached_state = NULL; 2641 struct new_sa_defrag_extent *new = NULL; 2642 int compress_type = 0; 2643 int ret; 2644 bool nolock; 2645 2646 nolock = btrfs_is_free_space_inode(inode); 2647 2648 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2649 ret = -EIO; 2650 goto out; 2651 } 2652 2653 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2654 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2655 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2656 if (nolock) 2657 trans = btrfs_join_transaction_nolock(root); 2658 else 2659 trans = btrfs_join_transaction(root); 2660 if (IS_ERR(trans)) { 2661 ret = PTR_ERR(trans); 2662 trans = NULL; 2663 goto out; 2664 } 2665 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2666 ret = btrfs_update_inode_fallback(trans, root, inode); 2667 if (ret) /* -ENOMEM or corruption */ 2668 btrfs_abort_transaction(trans, root, ret); 2669 goto out; 2670 } 2671 2672 lock_extent_bits(io_tree, ordered_extent->file_offset, 2673 ordered_extent->file_offset + ordered_extent->len - 1, 2674 0, &cached_state); 2675 2676 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2677 ordered_extent->file_offset + ordered_extent->len - 1, 2678 EXTENT_DEFRAG, 1, cached_state); 2679 if (ret) { 2680 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2681 if (last_snapshot >= BTRFS_I(inode)->generation) 2682 /* the inode is shared */ 2683 new = record_old_file_extents(inode, ordered_extent); 2684 2685 clear_extent_bit(io_tree, ordered_extent->file_offset, 2686 ordered_extent->file_offset + ordered_extent->len - 1, 2687 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2688 } 2689 2690 if (nolock) 2691 trans = btrfs_join_transaction_nolock(root); 2692 else 2693 trans = btrfs_join_transaction(root); 2694 if (IS_ERR(trans)) { 2695 ret = PTR_ERR(trans); 2696 trans = NULL; 2697 goto out_unlock; 2698 } 2699 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2700 2701 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2702 compress_type = ordered_extent->compress_type; 2703 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2704 BUG_ON(compress_type); 2705 ret = btrfs_mark_extent_written(trans, inode, 2706 ordered_extent->file_offset, 2707 ordered_extent->file_offset + 2708 ordered_extent->len); 2709 } else { 2710 BUG_ON(root == root->fs_info->tree_root); 2711 ret = insert_reserved_file_extent(trans, inode, 2712 ordered_extent->file_offset, 2713 ordered_extent->start, 2714 ordered_extent->disk_len, 2715 ordered_extent->len, 2716 ordered_extent->len, 2717 compress_type, 0, 0, 2718 BTRFS_FILE_EXTENT_REG); 2719 } 2720 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2721 ordered_extent->file_offset, ordered_extent->len, 2722 trans->transid); 2723 if (ret < 0) { 2724 btrfs_abort_transaction(trans, root, ret); 2725 goto out_unlock; 2726 } 2727 2728 add_pending_csums(trans, inode, ordered_extent->file_offset, 2729 &ordered_extent->list); 2730 2731 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2732 ret = btrfs_update_inode_fallback(trans, root, inode); 2733 if (ret) { /* -ENOMEM or corruption */ 2734 btrfs_abort_transaction(trans, root, ret); 2735 goto out_unlock; 2736 } 2737 ret = 0; 2738 out_unlock: 2739 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2740 ordered_extent->file_offset + 2741 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2742 out: 2743 if (root != root->fs_info->tree_root) 2744 btrfs_delalloc_release_metadata(inode, ordered_extent->len); 2745 if (trans) 2746 btrfs_end_transaction(trans, root); 2747 2748 if (ret) { 2749 clear_extent_uptodate(io_tree, ordered_extent->file_offset, 2750 ordered_extent->file_offset + 2751 ordered_extent->len - 1, NULL, GFP_NOFS); 2752 2753 /* 2754 * If the ordered extent had an IOERR or something else went 2755 * wrong we need to return the space for this ordered extent 2756 * back to the allocator. 2757 */ 2758 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2759 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2760 btrfs_free_reserved_extent(root, ordered_extent->start, 2761 ordered_extent->disk_len); 2762 } 2763 2764 2765 /* 2766 * This needs to be done to make sure anybody waiting knows we are done 2767 * updating everything for this ordered extent. 2768 */ 2769 btrfs_remove_ordered_extent(inode, ordered_extent); 2770 2771 /* for snapshot-aware defrag */ 2772 if (new) 2773 relink_file_extents(new); 2774 2775 /* once for us */ 2776 btrfs_put_ordered_extent(ordered_extent); 2777 /* once for the tree */ 2778 btrfs_put_ordered_extent(ordered_extent); 2779 2780 return ret; 2781 } 2782 2783 static void finish_ordered_fn(struct btrfs_work *work) 2784 { 2785 struct btrfs_ordered_extent *ordered_extent; 2786 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 2787 btrfs_finish_ordered_io(ordered_extent); 2788 } 2789 2790 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 2791 struct extent_state *state, int uptodate) 2792 { 2793 struct inode *inode = page->mapping->host; 2794 struct btrfs_root *root = BTRFS_I(inode)->root; 2795 struct btrfs_ordered_extent *ordered_extent = NULL; 2796 struct btrfs_workers *workers; 2797 2798 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 2799 2800 ClearPagePrivate2(page); 2801 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 2802 end - start + 1, uptodate)) 2803 return 0; 2804 2805 ordered_extent->work.func = finish_ordered_fn; 2806 ordered_extent->work.flags = 0; 2807 2808 if (btrfs_is_free_space_inode(inode)) 2809 workers = &root->fs_info->endio_freespace_worker; 2810 else 2811 workers = &root->fs_info->endio_write_workers; 2812 btrfs_queue_worker(workers, &ordered_extent->work); 2813 2814 return 0; 2815 } 2816 2817 /* 2818 * when reads are done, we need to check csums to verify the data is correct 2819 * if there's a match, we allow the bio to finish. If not, the code in 2820 * extent_io.c will try to find good copies for us. 2821 */ 2822 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end, 2823 struct extent_state *state, int mirror) 2824 { 2825 size_t offset = start - page_offset(page); 2826 struct inode *inode = page->mapping->host; 2827 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2828 char *kaddr; 2829 u64 private = ~(u32)0; 2830 int ret; 2831 struct btrfs_root *root = BTRFS_I(inode)->root; 2832 u32 csum = ~(u32)0; 2833 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 2834 DEFAULT_RATELIMIT_BURST); 2835 2836 if (PageChecked(page)) { 2837 ClearPageChecked(page); 2838 goto good; 2839 } 2840 2841 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 2842 goto good; 2843 2844 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 2845 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 2846 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, 2847 GFP_NOFS); 2848 return 0; 2849 } 2850 2851 if (state && state->start == start) { 2852 private = state->private; 2853 ret = 0; 2854 } else { 2855 ret = get_state_private(io_tree, start, &private); 2856 } 2857 kaddr = kmap_atomic(page); 2858 if (ret) 2859 goto zeroit; 2860 2861 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1); 2862 btrfs_csum_final(csum, (char *)&csum); 2863 if (csum != private) 2864 goto zeroit; 2865 2866 kunmap_atomic(kaddr); 2867 good: 2868 return 0; 2869 2870 zeroit: 2871 if (__ratelimit(&_rs)) 2872 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu", 2873 (unsigned long long)btrfs_ino(page->mapping->host), 2874 (unsigned long long)start, csum, 2875 (unsigned long long)private); 2876 memset(kaddr + offset, 1, end - start + 1); 2877 flush_dcache_page(page); 2878 kunmap_atomic(kaddr); 2879 if (private == 0) 2880 return 0; 2881 return -EIO; 2882 } 2883 2884 struct delayed_iput { 2885 struct list_head list; 2886 struct inode *inode; 2887 }; 2888 2889 /* JDM: If this is fs-wide, why can't we add a pointer to 2890 * btrfs_inode instead and avoid the allocation? */ 2891 void btrfs_add_delayed_iput(struct inode *inode) 2892 { 2893 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; 2894 struct delayed_iput *delayed; 2895 2896 if (atomic_add_unless(&inode->i_count, -1, 1)) 2897 return; 2898 2899 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); 2900 delayed->inode = inode; 2901 2902 spin_lock(&fs_info->delayed_iput_lock); 2903 list_add_tail(&delayed->list, &fs_info->delayed_iputs); 2904 spin_unlock(&fs_info->delayed_iput_lock); 2905 } 2906 2907 void btrfs_run_delayed_iputs(struct btrfs_root *root) 2908 { 2909 LIST_HEAD(list); 2910 struct btrfs_fs_info *fs_info = root->fs_info; 2911 struct delayed_iput *delayed; 2912 int empty; 2913 2914 spin_lock(&fs_info->delayed_iput_lock); 2915 empty = list_empty(&fs_info->delayed_iputs); 2916 spin_unlock(&fs_info->delayed_iput_lock); 2917 if (empty) 2918 return; 2919 2920 spin_lock(&fs_info->delayed_iput_lock); 2921 list_splice_init(&fs_info->delayed_iputs, &list); 2922 spin_unlock(&fs_info->delayed_iput_lock); 2923 2924 while (!list_empty(&list)) { 2925 delayed = list_entry(list.next, struct delayed_iput, list); 2926 list_del(&delayed->list); 2927 iput(delayed->inode); 2928 kfree(delayed); 2929 } 2930 } 2931 2932 /* 2933 * This is called in transaction commit time. If there are no orphan 2934 * files in the subvolume, it removes orphan item and frees block_rsv 2935 * structure. 2936 */ 2937 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 2938 struct btrfs_root *root) 2939 { 2940 struct btrfs_block_rsv *block_rsv; 2941 int ret; 2942 2943 if (atomic_read(&root->orphan_inodes) || 2944 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 2945 return; 2946 2947 spin_lock(&root->orphan_lock); 2948 if (atomic_read(&root->orphan_inodes)) { 2949 spin_unlock(&root->orphan_lock); 2950 return; 2951 } 2952 2953 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 2954 spin_unlock(&root->orphan_lock); 2955 return; 2956 } 2957 2958 block_rsv = root->orphan_block_rsv; 2959 root->orphan_block_rsv = NULL; 2960 spin_unlock(&root->orphan_lock); 2961 2962 if (root->orphan_item_inserted && 2963 btrfs_root_refs(&root->root_item) > 0) { 2964 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, 2965 root->root_key.objectid); 2966 BUG_ON(ret); 2967 root->orphan_item_inserted = 0; 2968 } 2969 2970 if (block_rsv) { 2971 WARN_ON(block_rsv->size > 0); 2972 btrfs_free_block_rsv(root, block_rsv); 2973 } 2974 } 2975 2976 /* 2977 * This creates an orphan entry for the given inode in case something goes 2978 * wrong in the middle of an unlink/truncate. 2979 * 2980 * NOTE: caller of this function should reserve 5 units of metadata for 2981 * this function. 2982 */ 2983 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) 2984 { 2985 struct btrfs_root *root = BTRFS_I(inode)->root; 2986 struct btrfs_block_rsv *block_rsv = NULL; 2987 int reserve = 0; 2988 int insert = 0; 2989 int ret; 2990 2991 if (!root->orphan_block_rsv) { 2992 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 2993 if (!block_rsv) 2994 return -ENOMEM; 2995 } 2996 2997 spin_lock(&root->orphan_lock); 2998 if (!root->orphan_block_rsv) { 2999 root->orphan_block_rsv = block_rsv; 3000 } else if (block_rsv) { 3001 btrfs_free_block_rsv(root, block_rsv); 3002 block_rsv = NULL; 3003 } 3004 3005 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3006 &BTRFS_I(inode)->runtime_flags)) { 3007 #if 0 3008 /* 3009 * For proper ENOSPC handling, we should do orphan 3010 * cleanup when mounting. But this introduces backward 3011 * compatibility issue. 3012 */ 3013 if (!xchg(&root->orphan_item_inserted, 1)) 3014 insert = 2; 3015 else 3016 insert = 1; 3017 #endif 3018 insert = 1; 3019 atomic_inc(&root->orphan_inodes); 3020 } 3021 3022 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3023 &BTRFS_I(inode)->runtime_flags)) 3024 reserve = 1; 3025 spin_unlock(&root->orphan_lock); 3026 3027 /* grab metadata reservation from transaction handle */ 3028 if (reserve) { 3029 ret = btrfs_orphan_reserve_metadata(trans, inode); 3030 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ 3031 } 3032 3033 /* insert an orphan item to track this unlinked/truncated file */ 3034 if (insert >= 1) { 3035 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 3036 if (ret && ret != -EEXIST) { 3037 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3038 &BTRFS_I(inode)->runtime_flags); 3039 btrfs_abort_transaction(trans, root, ret); 3040 return ret; 3041 } 3042 ret = 0; 3043 } 3044 3045 /* insert an orphan item to track subvolume contains orphan files */ 3046 if (insert >= 2) { 3047 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, 3048 root->root_key.objectid); 3049 if (ret && ret != -EEXIST) { 3050 btrfs_abort_transaction(trans, root, ret); 3051 return ret; 3052 } 3053 } 3054 return 0; 3055 } 3056 3057 /* 3058 * We have done the truncate/delete so we can go ahead and remove the orphan 3059 * item for this particular inode. 3060 */ 3061 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3062 struct inode *inode) 3063 { 3064 struct btrfs_root *root = BTRFS_I(inode)->root; 3065 int delete_item = 0; 3066 int release_rsv = 0; 3067 int ret = 0; 3068 3069 spin_lock(&root->orphan_lock); 3070 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3071 &BTRFS_I(inode)->runtime_flags)) 3072 delete_item = 1; 3073 3074 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3075 &BTRFS_I(inode)->runtime_flags)) 3076 release_rsv = 1; 3077 spin_unlock(&root->orphan_lock); 3078 3079 if (trans && delete_item) { 3080 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode)); 3081 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */ 3082 } 3083 3084 if (release_rsv) { 3085 btrfs_orphan_release_metadata(inode); 3086 atomic_dec(&root->orphan_inodes); 3087 } 3088 3089 return 0; 3090 } 3091 3092 /* 3093 * this cleans up any orphans that may be left on the list from the last use 3094 * of this root. 3095 */ 3096 int btrfs_orphan_cleanup(struct btrfs_root *root) 3097 { 3098 struct btrfs_path *path; 3099 struct extent_buffer *leaf; 3100 struct btrfs_key key, found_key; 3101 struct btrfs_trans_handle *trans; 3102 struct inode *inode; 3103 u64 last_objectid = 0; 3104 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3105 3106 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3107 return 0; 3108 3109 path = btrfs_alloc_path(); 3110 if (!path) { 3111 ret = -ENOMEM; 3112 goto out; 3113 } 3114 path->reada = -1; 3115 3116 key.objectid = BTRFS_ORPHAN_OBJECTID; 3117 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); 3118 key.offset = (u64)-1; 3119 3120 while (1) { 3121 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3122 if (ret < 0) 3123 goto out; 3124 3125 /* 3126 * if ret == 0 means we found what we were searching for, which 3127 * is weird, but possible, so only screw with path if we didn't 3128 * find the key and see if we have stuff that matches 3129 */ 3130 if (ret > 0) { 3131 ret = 0; 3132 if (path->slots[0] == 0) 3133 break; 3134 path->slots[0]--; 3135 } 3136 3137 /* pull out the item */ 3138 leaf = path->nodes[0]; 3139 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3140 3141 /* make sure the item matches what we want */ 3142 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3143 break; 3144 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY) 3145 break; 3146 3147 /* release the path since we're done with it */ 3148 btrfs_release_path(path); 3149 3150 /* 3151 * this is where we are basically btrfs_lookup, without the 3152 * crossing root thing. we store the inode number in the 3153 * offset of the orphan item. 3154 */ 3155 3156 if (found_key.offset == last_objectid) { 3157 btrfs_err(root->fs_info, 3158 "Error removing orphan entry, stopping orphan cleanup"); 3159 ret = -EINVAL; 3160 goto out; 3161 } 3162 3163 last_objectid = found_key.offset; 3164 3165 found_key.objectid = found_key.offset; 3166 found_key.type = BTRFS_INODE_ITEM_KEY; 3167 found_key.offset = 0; 3168 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); 3169 ret = PTR_RET(inode); 3170 if (ret && ret != -ESTALE) 3171 goto out; 3172 3173 if (ret == -ESTALE && root == root->fs_info->tree_root) { 3174 struct btrfs_root *dead_root; 3175 struct btrfs_fs_info *fs_info = root->fs_info; 3176 int is_dead_root = 0; 3177 3178 /* 3179 * this is an orphan in the tree root. Currently these 3180 * could come from 2 sources: 3181 * a) a snapshot deletion in progress 3182 * b) a free space cache inode 3183 * We need to distinguish those two, as the snapshot 3184 * orphan must not get deleted. 3185 * find_dead_roots already ran before us, so if this 3186 * is a snapshot deletion, we should find the root 3187 * in the dead_roots list 3188 */ 3189 spin_lock(&fs_info->trans_lock); 3190 list_for_each_entry(dead_root, &fs_info->dead_roots, 3191 root_list) { 3192 if (dead_root->root_key.objectid == 3193 found_key.objectid) { 3194 is_dead_root = 1; 3195 break; 3196 } 3197 } 3198 spin_unlock(&fs_info->trans_lock); 3199 if (is_dead_root) { 3200 /* prevent this orphan from being found again */ 3201 key.offset = found_key.objectid - 1; 3202 continue; 3203 } 3204 } 3205 /* 3206 * Inode is already gone but the orphan item is still there, 3207 * kill the orphan item. 3208 */ 3209 if (ret == -ESTALE) { 3210 trans = btrfs_start_transaction(root, 1); 3211 if (IS_ERR(trans)) { 3212 ret = PTR_ERR(trans); 3213 goto out; 3214 } 3215 btrfs_debug(root->fs_info, "auto deleting %Lu", 3216 found_key.objectid); 3217 ret = btrfs_del_orphan_item(trans, root, 3218 found_key.objectid); 3219 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */ 3220 btrfs_end_transaction(trans, root); 3221 continue; 3222 } 3223 3224 /* 3225 * add this inode to the orphan list so btrfs_orphan_del does 3226 * the proper thing when we hit it 3227 */ 3228 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3229 &BTRFS_I(inode)->runtime_flags); 3230 atomic_inc(&root->orphan_inodes); 3231 3232 /* if we have links, this was a truncate, lets do that */ 3233 if (inode->i_nlink) { 3234 if (!S_ISREG(inode->i_mode)) { 3235 WARN_ON(1); 3236 iput(inode); 3237 continue; 3238 } 3239 nr_truncate++; 3240 3241 /* 1 for the orphan item deletion. */ 3242 trans = btrfs_start_transaction(root, 1); 3243 if (IS_ERR(trans)) { 3244 iput(inode); 3245 ret = PTR_ERR(trans); 3246 goto out; 3247 } 3248 ret = btrfs_orphan_add(trans, inode); 3249 btrfs_end_transaction(trans, root); 3250 if (ret) { 3251 iput(inode); 3252 goto out; 3253 } 3254 3255 ret = btrfs_truncate(inode); 3256 if (ret) 3257 btrfs_orphan_del(NULL, inode); 3258 } else { 3259 nr_unlink++; 3260 } 3261 3262 /* this will do delete_inode and everything for us */ 3263 iput(inode); 3264 if (ret) 3265 goto out; 3266 } 3267 /* release the path since we're done with it */ 3268 btrfs_release_path(path); 3269 3270 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3271 3272 if (root->orphan_block_rsv) 3273 btrfs_block_rsv_release(root, root->orphan_block_rsv, 3274 (u64)-1); 3275 3276 if (root->orphan_block_rsv || root->orphan_item_inserted) { 3277 trans = btrfs_join_transaction(root); 3278 if (!IS_ERR(trans)) 3279 btrfs_end_transaction(trans, root); 3280 } 3281 3282 if (nr_unlink) 3283 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); 3284 if (nr_truncate) 3285 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); 3286 3287 out: 3288 if (ret) 3289 btrfs_crit(root->fs_info, 3290 "could not do orphan cleanup %d", ret); 3291 btrfs_free_path(path); 3292 return ret; 3293 } 3294 3295 /* 3296 * very simple check to peek ahead in the leaf looking for xattrs. If we 3297 * don't find any xattrs, we know there can't be any acls. 3298 * 3299 * slot is the slot the inode is in, objectid is the objectid of the inode 3300 */ 3301 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3302 int slot, u64 objectid) 3303 { 3304 u32 nritems = btrfs_header_nritems(leaf); 3305 struct btrfs_key found_key; 3306 static u64 xattr_access = 0; 3307 static u64 xattr_default = 0; 3308 int scanned = 0; 3309 3310 if (!xattr_access) { 3311 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS, 3312 strlen(POSIX_ACL_XATTR_ACCESS)); 3313 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT, 3314 strlen(POSIX_ACL_XATTR_DEFAULT)); 3315 } 3316 3317 slot++; 3318 while (slot < nritems) { 3319 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3320 3321 /* we found a different objectid, there must not be acls */ 3322 if (found_key.objectid != objectid) 3323 return 0; 3324 3325 /* we found an xattr, assume we've got an acl */ 3326 if (found_key.type == BTRFS_XATTR_ITEM_KEY) { 3327 if (found_key.offset == xattr_access || 3328 found_key.offset == xattr_default) 3329 return 1; 3330 } 3331 3332 /* 3333 * we found a key greater than an xattr key, there can't 3334 * be any acls later on 3335 */ 3336 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3337 return 0; 3338 3339 slot++; 3340 scanned++; 3341 3342 /* 3343 * it goes inode, inode backrefs, xattrs, extents, 3344 * so if there are a ton of hard links to an inode there can 3345 * be a lot of backrefs. Don't waste time searching too hard, 3346 * this is just an optimization 3347 */ 3348 if (scanned >= 8) 3349 break; 3350 } 3351 /* we hit the end of the leaf before we found an xattr or 3352 * something larger than an xattr. We have to assume the inode 3353 * has acls 3354 */ 3355 return 1; 3356 } 3357 3358 /* 3359 * read an inode from the btree into the in-memory inode 3360 */ 3361 static void btrfs_read_locked_inode(struct inode *inode) 3362 { 3363 struct btrfs_path *path; 3364 struct extent_buffer *leaf; 3365 struct btrfs_inode_item *inode_item; 3366 struct btrfs_timespec *tspec; 3367 struct btrfs_root *root = BTRFS_I(inode)->root; 3368 struct btrfs_key location; 3369 int maybe_acls; 3370 u32 rdev; 3371 int ret; 3372 bool filled = false; 3373 3374 ret = btrfs_fill_inode(inode, &rdev); 3375 if (!ret) 3376 filled = true; 3377 3378 path = btrfs_alloc_path(); 3379 if (!path) 3380 goto make_bad; 3381 3382 path->leave_spinning = 1; 3383 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3384 3385 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3386 if (ret) 3387 goto make_bad; 3388 3389 leaf = path->nodes[0]; 3390 3391 if (filled) 3392 goto cache_acl; 3393 3394 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3395 struct btrfs_inode_item); 3396 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3397 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3398 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3399 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3400 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); 3401 3402 tspec = btrfs_inode_atime(inode_item); 3403 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3404 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3405 3406 tspec = btrfs_inode_mtime(inode_item); 3407 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3408 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3409 3410 tspec = btrfs_inode_ctime(inode_item); 3411 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3412 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3413 3414 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3415 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3416 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3417 3418 /* 3419 * If we were modified in the current generation and evicted from memory 3420 * and then re-read we need to do a full sync since we don't have any 3421 * idea about which extents were modified before we were evicted from 3422 * cache. 3423 */ 3424 if (BTRFS_I(inode)->last_trans == root->fs_info->generation) 3425 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3426 &BTRFS_I(inode)->runtime_flags); 3427 3428 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3429 inode->i_generation = BTRFS_I(inode)->generation; 3430 inode->i_rdev = 0; 3431 rdev = btrfs_inode_rdev(leaf, inode_item); 3432 3433 BTRFS_I(inode)->index_cnt = (u64)-1; 3434 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3435 cache_acl: 3436 /* 3437 * try to precache a NULL acl entry for files that don't have 3438 * any xattrs or acls 3439 */ 3440 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3441 btrfs_ino(inode)); 3442 if (!maybe_acls) 3443 cache_no_acl(inode); 3444 3445 btrfs_free_path(path); 3446 3447 switch (inode->i_mode & S_IFMT) { 3448 case S_IFREG: 3449 inode->i_mapping->a_ops = &btrfs_aops; 3450 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3451 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3452 inode->i_fop = &btrfs_file_operations; 3453 inode->i_op = &btrfs_file_inode_operations; 3454 break; 3455 case S_IFDIR: 3456 inode->i_fop = &btrfs_dir_file_operations; 3457 if (root == root->fs_info->tree_root) 3458 inode->i_op = &btrfs_dir_ro_inode_operations; 3459 else 3460 inode->i_op = &btrfs_dir_inode_operations; 3461 break; 3462 case S_IFLNK: 3463 inode->i_op = &btrfs_symlink_inode_operations; 3464 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3465 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3466 break; 3467 default: 3468 inode->i_op = &btrfs_special_inode_operations; 3469 init_special_inode(inode, inode->i_mode, rdev); 3470 break; 3471 } 3472 3473 btrfs_update_iflags(inode); 3474 return; 3475 3476 make_bad: 3477 btrfs_free_path(path); 3478 make_bad_inode(inode); 3479 } 3480 3481 /* 3482 * given a leaf and an inode, copy the inode fields into the leaf 3483 */ 3484 static void fill_inode_item(struct btrfs_trans_handle *trans, 3485 struct extent_buffer *leaf, 3486 struct btrfs_inode_item *item, 3487 struct inode *inode) 3488 { 3489 struct btrfs_map_token token; 3490 3491 btrfs_init_map_token(&token); 3492 3493 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3494 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3495 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3496 &token); 3497 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3498 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3499 3500 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item), 3501 inode->i_atime.tv_sec, &token); 3502 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item), 3503 inode->i_atime.tv_nsec, &token); 3504 3505 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item), 3506 inode->i_mtime.tv_sec, &token); 3507 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item), 3508 inode->i_mtime.tv_nsec, &token); 3509 3510 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item), 3511 inode->i_ctime.tv_sec, &token); 3512 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item), 3513 inode->i_ctime.tv_nsec, &token); 3514 3515 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3516 &token); 3517 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3518 &token); 3519 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3520 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3521 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3522 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3523 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3524 } 3525 3526 /* 3527 * copy everything in the in-memory inode into the btree. 3528 */ 3529 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3530 struct btrfs_root *root, struct inode *inode) 3531 { 3532 struct btrfs_inode_item *inode_item; 3533 struct btrfs_path *path; 3534 struct extent_buffer *leaf; 3535 int ret; 3536 3537 path = btrfs_alloc_path(); 3538 if (!path) 3539 return -ENOMEM; 3540 3541 path->leave_spinning = 1; 3542 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3543 1); 3544 if (ret) { 3545 if (ret > 0) 3546 ret = -ENOENT; 3547 goto failed; 3548 } 3549 3550 btrfs_unlock_up_safe(path, 1); 3551 leaf = path->nodes[0]; 3552 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3553 struct btrfs_inode_item); 3554 3555 fill_inode_item(trans, leaf, inode_item, inode); 3556 btrfs_mark_buffer_dirty(leaf); 3557 btrfs_set_inode_last_trans(trans, inode); 3558 ret = 0; 3559 failed: 3560 btrfs_free_path(path); 3561 return ret; 3562 } 3563 3564 /* 3565 * copy everything in the in-memory inode into the btree. 3566 */ 3567 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3568 struct btrfs_root *root, struct inode *inode) 3569 { 3570 int ret; 3571 3572 /* 3573 * If the inode is a free space inode, we can deadlock during commit 3574 * if we put it into the delayed code. 3575 * 3576 * The data relocation inode should also be directly updated 3577 * without delay 3578 */ 3579 if (!btrfs_is_free_space_inode(inode) 3580 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) { 3581 btrfs_update_root_times(trans, root); 3582 3583 ret = btrfs_delayed_update_inode(trans, root, inode); 3584 if (!ret) 3585 btrfs_set_inode_last_trans(trans, inode); 3586 return ret; 3587 } 3588 3589 return btrfs_update_inode_item(trans, root, inode); 3590 } 3591 3592 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3593 struct btrfs_root *root, 3594 struct inode *inode) 3595 { 3596 int ret; 3597 3598 ret = btrfs_update_inode(trans, root, inode); 3599 if (ret == -ENOSPC) 3600 return btrfs_update_inode_item(trans, root, inode); 3601 return ret; 3602 } 3603 3604 /* 3605 * unlink helper that gets used here in inode.c and in the tree logging 3606 * recovery code. It remove a link in a directory with a given name, and 3607 * also drops the back refs in the inode to the directory 3608 */ 3609 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3610 struct btrfs_root *root, 3611 struct inode *dir, struct inode *inode, 3612 const char *name, int name_len) 3613 { 3614 struct btrfs_path *path; 3615 int ret = 0; 3616 struct extent_buffer *leaf; 3617 struct btrfs_dir_item *di; 3618 struct btrfs_key key; 3619 u64 index; 3620 u64 ino = btrfs_ino(inode); 3621 u64 dir_ino = btrfs_ino(dir); 3622 3623 path = btrfs_alloc_path(); 3624 if (!path) { 3625 ret = -ENOMEM; 3626 goto out; 3627 } 3628 3629 path->leave_spinning = 1; 3630 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3631 name, name_len, -1); 3632 if (IS_ERR(di)) { 3633 ret = PTR_ERR(di); 3634 goto err; 3635 } 3636 if (!di) { 3637 ret = -ENOENT; 3638 goto err; 3639 } 3640 leaf = path->nodes[0]; 3641 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3642 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3643 if (ret) 3644 goto err; 3645 btrfs_release_path(path); 3646 3647 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3648 dir_ino, &index); 3649 if (ret) { 3650 btrfs_info(root->fs_info, 3651 "failed to delete reference to %.*s, inode %llu parent %llu", 3652 name_len, name, 3653 (unsigned long long)ino, (unsigned long long)dir_ino); 3654 btrfs_abort_transaction(trans, root, ret); 3655 goto err; 3656 } 3657 3658 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3659 if (ret) { 3660 btrfs_abort_transaction(trans, root, ret); 3661 goto err; 3662 } 3663 3664 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, 3665 inode, dir_ino); 3666 if (ret != 0 && ret != -ENOENT) { 3667 btrfs_abort_transaction(trans, root, ret); 3668 goto err; 3669 } 3670 3671 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, 3672 dir, index); 3673 if (ret == -ENOENT) 3674 ret = 0; 3675 else if (ret) 3676 btrfs_abort_transaction(trans, root, ret); 3677 err: 3678 btrfs_free_path(path); 3679 if (ret) 3680 goto out; 3681 3682 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3683 inode_inc_iversion(inode); 3684 inode_inc_iversion(dir); 3685 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3686 ret = btrfs_update_inode(trans, root, dir); 3687 out: 3688 return ret; 3689 } 3690 3691 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3692 struct btrfs_root *root, 3693 struct inode *dir, struct inode *inode, 3694 const char *name, int name_len) 3695 { 3696 int ret; 3697 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 3698 if (!ret) { 3699 btrfs_drop_nlink(inode); 3700 ret = btrfs_update_inode(trans, root, inode); 3701 } 3702 return ret; 3703 } 3704 3705 /* 3706 * helper to start transaction for unlink and rmdir. 3707 * 3708 * unlink and rmdir are special in btrfs, they do not always free space, so 3709 * if we cannot make our reservations the normal way try and see if there is 3710 * plenty of slack room in the global reserve to migrate, otherwise we cannot 3711 * allow the unlink to occur. 3712 */ 3713 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) 3714 { 3715 struct btrfs_trans_handle *trans; 3716 struct btrfs_root *root = BTRFS_I(dir)->root; 3717 int ret; 3718 3719 /* 3720 * 1 for the possible orphan item 3721 * 1 for the dir item 3722 * 1 for the dir index 3723 * 1 for the inode ref 3724 * 1 for the inode 3725 */ 3726 trans = btrfs_start_transaction(root, 5); 3727 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) 3728 return trans; 3729 3730 if (PTR_ERR(trans) == -ENOSPC) { 3731 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5); 3732 3733 trans = btrfs_start_transaction(root, 0); 3734 if (IS_ERR(trans)) 3735 return trans; 3736 ret = btrfs_cond_migrate_bytes(root->fs_info, 3737 &root->fs_info->trans_block_rsv, 3738 num_bytes, 5); 3739 if (ret) { 3740 btrfs_end_transaction(trans, root); 3741 return ERR_PTR(ret); 3742 } 3743 trans->block_rsv = &root->fs_info->trans_block_rsv; 3744 trans->bytes_reserved = num_bytes; 3745 } 3746 return trans; 3747 } 3748 3749 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 3750 { 3751 struct btrfs_root *root = BTRFS_I(dir)->root; 3752 struct btrfs_trans_handle *trans; 3753 struct inode *inode = dentry->d_inode; 3754 int ret; 3755 3756 trans = __unlink_start_trans(dir); 3757 if (IS_ERR(trans)) 3758 return PTR_ERR(trans); 3759 3760 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0); 3761 3762 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3763 dentry->d_name.name, dentry->d_name.len); 3764 if (ret) 3765 goto out; 3766 3767 if (inode->i_nlink == 0) { 3768 ret = btrfs_orphan_add(trans, inode); 3769 if (ret) 3770 goto out; 3771 } 3772 3773 out: 3774 btrfs_end_transaction(trans, root); 3775 btrfs_btree_balance_dirty(root); 3776 return ret; 3777 } 3778 3779 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 3780 struct btrfs_root *root, 3781 struct inode *dir, u64 objectid, 3782 const char *name, int name_len) 3783 { 3784 struct btrfs_path *path; 3785 struct extent_buffer *leaf; 3786 struct btrfs_dir_item *di; 3787 struct btrfs_key key; 3788 u64 index; 3789 int ret; 3790 u64 dir_ino = btrfs_ino(dir); 3791 3792 path = btrfs_alloc_path(); 3793 if (!path) 3794 return -ENOMEM; 3795 3796 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3797 name, name_len, -1); 3798 if (IS_ERR_OR_NULL(di)) { 3799 if (!di) 3800 ret = -ENOENT; 3801 else 3802 ret = PTR_ERR(di); 3803 goto out; 3804 } 3805 3806 leaf = path->nodes[0]; 3807 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3808 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 3809 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3810 if (ret) { 3811 btrfs_abort_transaction(trans, root, ret); 3812 goto out; 3813 } 3814 btrfs_release_path(path); 3815 3816 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, 3817 objectid, root->root_key.objectid, 3818 dir_ino, &index, name, name_len); 3819 if (ret < 0) { 3820 if (ret != -ENOENT) { 3821 btrfs_abort_transaction(trans, root, ret); 3822 goto out; 3823 } 3824 di = btrfs_search_dir_index_item(root, path, dir_ino, 3825 name, name_len); 3826 if (IS_ERR_OR_NULL(di)) { 3827 if (!di) 3828 ret = -ENOENT; 3829 else 3830 ret = PTR_ERR(di); 3831 btrfs_abort_transaction(trans, root, ret); 3832 goto out; 3833 } 3834 3835 leaf = path->nodes[0]; 3836 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3837 btrfs_release_path(path); 3838 index = key.offset; 3839 } 3840 btrfs_release_path(path); 3841 3842 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3843 if (ret) { 3844 btrfs_abort_transaction(trans, root, ret); 3845 goto out; 3846 } 3847 3848 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3849 inode_inc_iversion(dir); 3850 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3851 ret = btrfs_update_inode_fallback(trans, root, dir); 3852 if (ret) 3853 btrfs_abort_transaction(trans, root, ret); 3854 out: 3855 btrfs_free_path(path); 3856 return ret; 3857 } 3858 3859 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 3860 { 3861 struct inode *inode = dentry->d_inode; 3862 int err = 0; 3863 struct btrfs_root *root = BTRFS_I(dir)->root; 3864 struct btrfs_trans_handle *trans; 3865 3866 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 3867 return -ENOTEMPTY; 3868 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) 3869 return -EPERM; 3870 3871 trans = __unlink_start_trans(dir); 3872 if (IS_ERR(trans)) 3873 return PTR_ERR(trans); 3874 3875 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 3876 err = btrfs_unlink_subvol(trans, root, dir, 3877 BTRFS_I(inode)->location.objectid, 3878 dentry->d_name.name, 3879 dentry->d_name.len); 3880 goto out; 3881 } 3882 3883 err = btrfs_orphan_add(trans, inode); 3884 if (err) 3885 goto out; 3886 3887 /* now the directory is empty */ 3888 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3889 dentry->d_name.name, dentry->d_name.len); 3890 if (!err) 3891 btrfs_i_size_write(inode, 0); 3892 out: 3893 btrfs_end_transaction(trans, root); 3894 btrfs_btree_balance_dirty(root); 3895 3896 return err; 3897 } 3898 3899 /* 3900 * this can truncate away extent items, csum items and directory items. 3901 * It starts at a high offset and removes keys until it can't find 3902 * any higher than new_size 3903 * 3904 * csum items that cross the new i_size are truncated to the new size 3905 * as well. 3906 * 3907 * min_type is the minimum key type to truncate down to. If set to 0, this 3908 * will kill all the items on this inode, including the INODE_ITEM_KEY. 3909 */ 3910 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 3911 struct btrfs_root *root, 3912 struct inode *inode, 3913 u64 new_size, u32 min_type) 3914 { 3915 struct btrfs_path *path; 3916 struct extent_buffer *leaf; 3917 struct btrfs_file_extent_item *fi; 3918 struct btrfs_key key; 3919 struct btrfs_key found_key; 3920 u64 extent_start = 0; 3921 u64 extent_num_bytes = 0; 3922 u64 extent_offset = 0; 3923 u64 item_end = 0; 3924 u32 found_type = (u8)-1; 3925 int found_extent; 3926 int del_item; 3927 int pending_del_nr = 0; 3928 int pending_del_slot = 0; 3929 int extent_type = -1; 3930 int ret; 3931 int err = 0; 3932 u64 ino = btrfs_ino(inode); 3933 3934 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 3935 3936 path = btrfs_alloc_path(); 3937 if (!path) 3938 return -ENOMEM; 3939 path->reada = -1; 3940 3941 /* 3942 * We want to drop from the next block forward in case this new size is 3943 * not block aligned since we will be keeping the last block of the 3944 * extent just the way it is. 3945 */ 3946 if (root->ref_cows || root == root->fs_info->tree_root) 3947 btrfs_drop_extent_cache(inode, ALIGN(new_size, 3948 root->sectorsize), (u64)-1, 0); 3949 3950 /* 3951 * This function is also used to drop the items in the log tree before 3952 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 3953 * it is used to drop the loged items. So we shouldn't kill the delayed 3954 * items. 3955 */ 3956 if (min_type == 0 && root == BTRFS_I(inode)->root) 3957 btrfs_kill_delayed_inode_items(inode); 3958 3959 key.objectid = ino; 3960 key.offset = (u64)-1; 3961 key.type = (u8)-1; 3962 3963 search_again: 3964 path->leave_spinning = 1; 3965 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 3966 if (ret < 0) { 3967 err = ret; 3968 goto out; 3969 } 3970 3971 if (ret > 0) { 3972 /* there are no items in the tree for us to truncate, we're 3973 * done 3974 */ 3975 if (path->slots[0] == 0) 3976 goto out; 3977 path->slots[0]--; 3978 } 3979 3980 while (1) { 3981 fi = NULL; 3982 leaf = path->nodes[0]; 3983 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3984 found_type = btrfs_key_type(&found_key); 3985 3986 if (found_key.objectid != ino) 3987 break; 3988 3989 if (found_type < min_type) 3990 break; 3991 3992 item_end = found_key.offset; 3993 if (found_type == BTRFS_EXTENT_DATA_KEY) { 3994 fi = btrfs_item_ptr(leaf, path->slots[0], 3995 struct btrfs_file_extent_item); 3996 extent_type = btrfs_file_extent_type(leaf, fi); 3997 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 3998 item_end += 3999 btrfs_file_extent_num_bytes(leaf, fi); 4000 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4001 item_end += btrfs_file_extent_inline_len(leaf, 4002 fi); 4003 } 4004 item_end--; 4005 } 4006 if (found_type > min_type) { 4007 del_item = 1; 4008 } else { 4009 if (item_end < new_size) 4010 break; 4011 if (found_key.offset >= new_size) 4012 del_item = 1; 4013 else 4014 del_item = 0; 4015 } 4016 found_extent = 0; 4017 /* FIXME, shrink the extent if the ref count is only 1 */ 4018 if (found_type != BTRFS_EXTENT_DATA_KEY) 4019 goto delete; 4020 4021 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4022 u64 num_dec; 4023 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4024 if (!del_item) { 4025 u64 orig_num_bytes = 4026 btrfs_file_extent_num_bytes(leaf, fi); 4027 extent_num_bytes = ALIGN(new_size - 4028 found_key.offset, 4029 root->sectorsize); 4030 btrfs_set_file_extent_num_bytes(leaf, fi, 4031 extent_num_bytes); 4032 num_dec = (orig_num_bytes - 4033 extent_num_bytes); 4034 if (root->ref_cows && extent_start != 0) 4035 inode_sub_bytes(inode, num_dec); 4036 btrfs_mark_buffer_dirty(leaf); 4037 } else { 4038 extent_num_bytes = 4039 btrfs_file_extent_disk_num_bytes(leaf, 4040 fi); 4041 extent_offset = found_key.offset - 4042 btrfs_file_extent_offset(leaf, fi); 4043 4044 /* FIXME blocksize != 4096 */ 4045 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4046 if (extent_start != 0) { 4047 found_extent = 1; 4048 if (root->ref_cows) 4049 inode_sub_bytes(inode, num_dec); 4050 } 4051 } 4052 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4053 /* 4054 * we can't truncate inline items that have had 4055 * special encodings 4056 */ 4057 if (!del_item && 4058 btrfs_file_extent_compression(leaf, fi) == 0 && 4059 btrfs_file_extent_encryption(leaf, fi) == 0 && 4060 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4061 u32 size = new_size - found_key.offset; 4062 4063 if (root->ref_cows) { 4064 inode_sub_bytes(inode, item_end + 1 - 4065 new_size); 4066 } 4067 size = 4068 btrfs_file_extent_calc_inline_size(size); 4069 btrfs_truncate_item(root, path, size, 1); 4070 } else if (root->ref_cows) { 4071 inode_sub_bytes(inode, item_end + 1 - 4072 found_key.offset); 4073 } 4074 } 4075 delete: 4076 if (del_item) { 4077 if (!pending_del_nr) { 4078 /* no pending yet, add ourselves */ 4079 pending_del_slot = path->slots[0]; 4080 pending_del_nr = 1; 4081 } else if (pending_del_nr && 4082 path->slots[0] + 1 == pending_del_slot) { 4083 /* hop on the pending chunk */ 4084 pending_del_nr++; 4085 pending_del_slot = path->slots[0]; 4086 } else { 4087 BUG(); 4088 } 4089 } else { 4090 break; 4091 } 4092 if (found_extent && (root->ref_cows || 4093 root == root->fs_info->tree_root)) { 4094 btrfs_set_path_blocking(path); 4095 ret = btrfs_free_extent(trans, root, extent_start, 4096 extent_num_bytes, 0, 4097 btrfs_header_owner(leaf), 4098 ino, extent_offset, 0); 4099 BUG_ON(ret); 4100 } 4101 4102 if (found_type == BTRFS_INODE_ITEM_KEY) 4103 break; 4104 4105 if (path->slots[0] == 0 || 4106 path->slots[0] != pending_del_slot) { 4107 if (pending_del_nr) { 4108 ret = btrfs_del_items(trans, root, path, 4109 pending_del_slot, 4110 pending_del_nr); 4111 if (ret) { 4112 btrfs_abort_transaction(trans, 4113 root, ret); 4114 goto error; 4115 } 4116 pending_del_nr = 0; 4117 } 4118 btrfs_release_path(path); 4119 goto search_again; 4120 } else { 4121 path->slots[0]--; 4122 } 4123 } 4124 out: 4125 if (pending_del_nr) { 4126 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4127 pending_del_nr); 4128 if (ret) 4129 btrfs_abort_transaction(trans, root, ret); 4130 } 4131 error: 4132 btrfs_free_path(path); 4133 return err; 4134 } 4135 4136 /* 4137 * btrfs_truncate_page - read, zero a chunk and write a page 4138 * @inode - inode that we're zeroing 4139 * @from - the offset to start zeroing 4140 * @len - the length to zero, 0 to zero the entire range respective to the 4141 * offset 4142 * @front - zero up to the offset instead of from the offset on 4143 * 4144 * This will find the page for the "from" offset and cow the page and zero the 4145 * part we want to zero. This is used with truncate and hole punching. 4146 */ 4147 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, 4148 int front) 4149 { 4150 struct address_space *mapping = inode->i_mapping; 4151 struct btrfs_root *root = BTRFS_I(inode)->root; 4152 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4153 struct btrfs_ordered_extent *ordered; 4154 struct extent_state *cached_state = NULL; 4155 char *kaddr; 4156 u32 blocksize = root->sectorsize; 4157 pgoff_t index = from >> PAGE_CACHE_SHIFT; 4158 unsigned offset = from & (PAGE_CACHE_SIZE-1); 4159 struct page *page; 4160 gfp_t mask = btrfs_alloc_write_mask(mapping); 4161 int ret = 0; 4162 u64 page_start; 4163 u64 page_end; 4164 4165 if ((offset & (blocksize - 1)) == 0 && 4166 (!len || ((len & (blocksize - 1)) == 0))) 4167 goto out; 4168 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 4169 if (ret) 4170 goto out; 4171 4172 again: 4173 page = find_or_create_page(mapping, index, mask); 4174 if (!page) { 4175 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4176 ret = -ENOMEM; 4177 goto out; 4178 } 4179 4180 page_start = page_offset(page); 4181 page_end = page_start + PAGE_CACHE_SIZE - 1; 4182 4183 if (!PageUptodate(page)) { 4184 ret = btrfs_readpage(NULL, page); 4185 lock_page(page); 4186 if (page->mapping != mapping) { 4187 unlock_page(page); 4188 page_cache_release(page); 4189 goto again; 4190 } 4191 if (!PageUptodate(page)) { 4192 ret = -EIO; 4193 goto out_unlock; 4194 } 4195 } 4196 wait_on_page_writeback(page); 4197 4198 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 4199 set_page_extent_mapped(page); 4200 4201 ordered = btrfs_lookup_ordered_extent(inode, page_start); 4202 if (ordered) { 4203 unlock_extent_cached(io_tree, page_start, page_end, 4204 &cached_state, GFP_NOFS); 4205 unlock_page(page); 4206 page_cache_release(page); 4207 btrfs_start_ordered_extent(inode, ordered, 1); 4208 btrfs_put_ordered_extent(ordered); 4209 goto again; 4210 } 4211 4212 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 4213 EXTENT_DIRTY | EXTENT_DELALLOC | 4214 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4215 0, 0, &cached_state, GFP_NOFS); 4216 4217 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 4218 &cached_state); 4219 if (ret) { 4220 unlock_extent_cached(io_tree, page_start, page_end, 4221 &cached_state, GFP_NOFS); 4222 goto out_unlock; 4223 } 4224 4225 if (offset != PAGE_CACHE_SIZE) { 4226 if (!len) 4227 len = PAGE_CACHE_SIZE - offset; 4228 kaddr = kmap(page); 4229 if (front) 4230 memset(kaddr, 0, offset); 4231 else 4232 memset(kaddr + offset, 0, len); 4233 flush_dcache_page(page); 4234 kunmap(page); 4235 } 4236 ClearPageChecked(page); 4237 set_page_dirty(page); 4238 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, 4239 GFP_NOFS); 4240 4241 out_unlock: 4242 if (ret) 4243 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4244 unlock_page(page); 4245 page_cache_release(page); 4246 out: 4247 return ret; 4248 } 4249 4250 /* 4251 * This function puts in dummy file extents for the area we're creating a hole 4252 * for. So if we are truncating this file to a larger size we need to insert 4253 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4254 * the range between oldsize and size 4255 */ 4256 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4257 { 4258 struct btrfs_trans_handle *trans; 4259 struct btrfs_root *root = BTRFS_I(inode)->root; 4260 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4261 struct extent_map *em = NULL; 4262 struct extent_state *cached_state = NULL; 4263 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4264 u64 hole_start = ALIGN(oldsize, root->sectorsize); 4265 u64 block_end = ALIGN(size, root->sectorsize); 4266 u64 last_byte; 4267 u64 cur_offset; 4268 u64 hole_size; 4269 int err = 0; 4270 4271 /* 4272 * If our size started in the middle of a page we need to zero out the 4273 * rest of the page before we expand the i_size, otherwise we could 4274 * expose stale data. 4275 */ 4276 err = btrfs_truncate_page(inode, oldsize, 0, 0); 4277 if (err) 4278 return err; 4279 4280 if (size <= hole_start) 4281 return 0; 4282 4283 while (1) { 4284 struct btrfs_ordered_extent *ordered; 4285 btrfs_wait_ordered_range(inode, hole_start, 4286 block_end - hole_start); 4287 lock_extent_bits(io_tree, hole_start, block_end - 1, 0, 4288 &cached_state); 4289 ordered = btrfs_lookup_ordered_extent(inode, hole_start); 4290 if (!ordered) 4291 break; 4292 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4293 &cached_state, GFP_NOFS); 4294 btrfs_put_ordered_extent(ordered); 4295 } 4296 4297 cur_offset = hole_start; 4298 while (1) { 4299 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 4300 block_end - cur_offset, 0); 4301 if (IS_ERR(em)) { 4302 err = PTR_ERR(em); 4303 em = NULL; 4304 break; 4305 } 4306 last_byte = min(extent_map_end(em), block_end); 4307 last_byte = ALIGN(last_byte , root->sectorsize); 4308 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4309 struct extent_map *hole_em; 4310 hole_size = last_byte - cur_offset; 4311 4312 trans = btrfs_start_transaction(root, 3); 4313 if (IS_ERR(trans)) { 4314 err = PTR_ERR(trans); 4315 break; 4316 } 4317 4318 err = btrfs_drop_extents(trans, root, inode, 4319 cur_offset, 4320 cur_offset + hole_size, 1); 4321 if (err) { 4322 btrfs_abort_transaction(trans, root, err); 4323 btrfs_end_transaction(trans, root); 4324 break; 4325 } 4326 4327 err = btrfs_insert_file_extent(trans, root, 4328 btrfs_ino(inode), cur_offset, 0, 4329 0, hole_size, 0, hole_size, 4330 0, 0, 0); 4331 if (err) { 4332 btrfs_abort_transaction(trans, root, err); 4333 btrfs_end_transaction(trans, root); 4334 break; 4335 } 4336 4337 btrfs_drop_extent_cache(inode, cur_offset, 4338 cur_offset + hole_size - 1, 0); 4339 hole_em = alloc_extent_map(); 4340 if (!hole_em) { 4341 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4342 &BTRFS_I(inode)->runtime_flags); 4343 goto next; 4344 } 4345 hole_em->start = cur_offset; 4346 hole_em->len = hole_size; 4347 hole_em->orig_start = cur_offset; 4348 4349 hole_em->block_start = EXTENT_MAP_HOLE; 4350 hole_em->block_len = 0; 4351 hole_em->orig_block_len = 0; 4352 hole_em->ram_bytes = hole_size; 4353 hole_em->bdev = root->fs_info->fs_devices->latest_bdev; 4354 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4355 hole_em->generation = trans->transid; 4356 4357 while (1) { 4358 write_lock(&em_tree->lock); 4359 err = add_extent_mapping(em_tree, hole_em, 1); 4360 write_unlock(&em_tree->lock); 4361 if (err != -EEXIST) 4362 break; 4363 btrfs_drop_extent_cache(inode, cur_offset, 4364 cur_offset + 4365 hole_size - 1, 0); 4366 } 4367 free_extent_map(hole_em); 4368 next: 4369 btrfs_update_inode(trans, root, inode); 4370 btrfs_end_transaction(trans, root); 4371 } 4372 free_extent_map(em); 4373 em = NULL; 4374 cur_offset = last_byte; 4375 if (cur_offset >= block_end) 4376 break; 4377 } 4378 4379 free_extent_map(em); 4380 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4381 GFP_NOFS); 4382 return err; 4383 } 4384 4385 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4386 { 4387 struct btrfs_root *root = BTRFS_I(inode)->root; 4388 struct btrfs_trans_handle *trans; 4389 loff_t oldsize = i_size_read(inode); 4390 loff_t newsize = attr->ia_size; 4391 int mask = attr->ia_valid; 4392 int ret; 4393 4394 if (newsize == oldsize) 4395 return 0; 4396 4397 /* 4398 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4399 * special case where we need to update the times despite not having 4400 * these flags set. For all other operations the VFS set these flags 4401 * explicitly if it wants a timestamp update. 4402 */ 4403 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME)))) 4404 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb); 4405 4406 if (newsize > oldsize) { 4407 truncate_pagecache(inode, oldsize, newsize); 4408 ret = btrfs_cont_expand(inode, oldsize, newsize); 4409 if (ret) 4410 return ret; 4411 4412 trans = btrfs_start_transaction(root, 1); 4413 if (IS_ERR(trans)) 4414 return PTR_ERR(trans); 4415 4416 i_size_write(inode, newsize); 4417 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4418 ret = btrfs_update_inode(trans, root, inode); 4419 btrfs_end_transaction(trans, root); 4420 } else { 4421 4422 /* 4423 * We're truncating a file that used to have good data down to 4424 * zero. Make sure it gets into the ordered flush list so that 4425 * any new writes get down to disk quickly. 4426 */ 4427 if (newsize == 0) 4428 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4429 &BTRFS_I(inode)->runtime_flags); 4430 4431 /* 4432 * 1 for the orphan item we're going to add 4433 * 1 for the orphan item deletion. 4434 */ 4435 trans = btrfs_start_transaction(root, 2); 4436 if (IS_ERR(trans)) 4437 return PTR_ERR(trans); 4438 4439 /* 4440 * We need to do this in case we fail at _any_ point during the 4441 * actual truncate. Once we do the truncate_setsize we could 4442 * invalidate pages which forces any outstanding ordered io to 4443 * be instantly completed which will give us extents that need 4444 * to be truncated. If we fail to get an orphan inode down we 4445 * could have left over extents that were never meant to live, 4446 * so we need to garuntee from this point on that everything 4447 * will be consistent. 4448 */ 4449 ret = btrfs_orphan_add(trans, inode); 4450 btrfs_end_transaction(trans, root); 4451 if (ret) 4452 return ret; 4453 4454 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4455 truncate_setsize(inode, newsize); 4456 4457 /* Disable nonlocked read DIO to avoid the end less truncate */ 4458 btrfs_inode_block_unlocked_dio(inode); 4459 inode_dio_wait(inode); 4460 btrfs_inode_resume_unlocked_dio(inode); 4461 4462 ret = btrfs_truncate(inode); 4463 if (ret && inode->i_nlink) 4464 btrfs_orphan_del(NULL, inode); 4465 } 4466 4467 return ret; 4468 } 4469 4470 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 4471 { 4472 struct inode *inode = dentry->d_inode; 4473 struct btrfs_root *root = BTRFS_I(inode)->root; 4474 int err; 4475 4476 if (btrfs_root_readonly(root)) 4477 return -EROFS; 4478 4479 err = inode_change_ok(inode, attr); 4480 if (err) 4481 return err; 4482 4483 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 4484 err = btrfs_setsize(inode, attr); 4485 if (err) 4486 return err; 4487 } 4488 4489 if (attr->ia_valid) { 4490 setattr_copy(inode, attr); 4491 inode_inc_iversion(inode); 4492 err = btrfs_dirty_inode(inode); 4493 4494 if (!err && attr->ia_valid & ATTR_MODE) 4495 err = btrfs_acl_chmod(inode); 4496 } 4497 4498 return err; 4499 } 4500 4501 void btrfs_evict_inode(struct inode *inode) 4502 { 4503 struct btrfs_trans_handle *trans; 4504 struct btrfs_root *root = BTRFS_I(inode)->root; 4505 struct btrfs_block_rsv *rsv, *global_rsv; 4506 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 4507 int ret; 4508 4509 trace_btrfs_inode_evict(inode); 4510 4511 truncate_inode_pages(&inode->i_data, 0); 4512 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 || 4513 btrfs_is_free_space_inode(inode))) 4514 goto no_delete; 4515 4516 if (is_bad_inode(inode)) { 4517 btrfs_orphan_del(NULL, inode); 4518 goto no_delete; 4519 } 4520 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 4521 btrfs_wait_ordered_range(inode, 0, (u64)-1); 4522 4523 if (root->fs_info->log_root_recovering) { 4524 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 4525 &BTRFS_I(inode)->runtime_flags)); 4526 goto no_delete; 4527 } 4528 4529 if (inode->i_nlink > 0) { 4530 BUG_ON(btrfs_root_refs(&root->root_item) != 0); 4531 goto no_delete; 4532 } 4533 4534 ret = btrfs_commit_inode_delayed_inode(inode); 4535 if (ret) { 4536 btrfs_orphan_del(NULL, inode); 4537 goto no_delete; 4538 } 4539 4540 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 4541 if (!rsv) { 4542 btrfs_orphan_del(NULL, inode); 4543 goto no_delete; 4544 } 4545 rsv->size = min_size; 4546 rsv->failfast = 1; 4547 global_rsv = &root->fs_info->global_block_rsv; 4548 4549 btrfs_i_size_write(inode, 0); 4550 4551 /* 4552 * This is a bit simpler than btrfs_truncate since we've already 4553 * reserved our space for our orphan item in the unlink, so we just 4554 * need to reserve some slack space in case we add bytes and update 4555 * inode item when doing the truncate. 4556 */ 4557 while (1) { 4558 ret = btrfs_block_rsv_refill(root, rsv, min_size, 4559 BTRFS_RESERVE_FLUSH_LIMIT); 4560 4561 /* 4562 * Try and steal from the global reserve since we will 4563 * likely not use this space anyway, we want to try as 4564 * hard as possible to get this to work. 4565 */ 4566 if (ret) 4567 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size); 4568 4569 if (ret) { 4570 btrfs_warn(root->fs_info, 4571 "Could not get space for a delete, will truncate on mount %d", 4572 ret); 4573 btrfs_orphan_del(NULL, inode); 4574 btrfs_free_block_rsv(root, rsv); 4575 goto no_delete; 4576 } 4577 4578 trans = btrfs_join_transaction(root); 4579 if (IS_ERR(trans)) { 4580 btrfs_orphan_del(NULL, inode); 4581 btrfs_free_block_rsv(root, rsv); 4582 goto no_delete; 4583 } 4584 4585 trans->block_rsv = rsv; 4586 4587 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 4588 if (ret != -ENOSPC) 4589 break; 4590 4591 trans->block_rsv = &root->fs_info->trans_block_rsv; 4592 btrfs_end_transaction(trans, root); 4593 trans = NULL; 4594 btrfs_btree_balance_dirty(root); 4595 } 4596 4597 btrfs_free_block_rsv(root, rsv); 4598 4599 if (ret == 0) { 4600 trans->block_rsv = root->orphan_block_rsv; 4601 ret = btrfs_orphan_del(trans, inode); 4602 BUG_ON(ret); 4603 } 4604 4605 trans->block_rsv = &root->fs_info->trans_block_rsv; 4606 if (!(root == root->fs_info->tree_root || 4607 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 4608 btrfs_return_ino(root, btrfs_ino(inode)); 4609 4610 btrfs_end_transaction(trans, root); 4611 btrfs_btree_balance_dirty(root); 4612 no_delete: 4613 btrfs_remove_delayed_node(inode); 4614 clear_inode(inode); 4615 return; 4616 } 4617 4618 /* 4619 * this returns the key found in the dir entry in the location pointer. 4620 * If no dir entries were found, location->objectid is 0. 4621 */ 4622 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 4623 struct btrfs_key *location) 4624 { 4625 const char *name = dentry->d_name.name; 4626 int namelen = dentry->d_name.len; 4627 struct btrfs_dir_item *di; 4628 struct btrfs_path *path; 4629 struct btrfs_root *root = BTRFS_I(dir)->root; 4630 int ret = 0; 4631 4632 path = btrfs_alloc_path(); 4633 if (!path) 4634 return -ENOMEM; 4635 4636 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, 4637 namelen, 0); 4638 if (IS_ERR(di)) 4639 ret = PTR_ERR(di); 4640 4641 if (IS_ERR_OR_NULL(di)) 4642 goto out_err; 4643 4644 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 4645 out: 4646 btrfs_free_path(path); 4647 return ret; 4648 out_err: 4649 location->objectid = 0; 4650 goto out; 4651 } 4652 4653 /* 4654 * when we hit a tree root in a directory, the btrfs part of the inode 4655 * needs to be changed to reflect the root directory of the tree root. This 4656 * is kind of like crossing a mount point. 4657 */ 4658 static int fixup_tree_root_location(struct btrfs_root *root, 4659 struct inode *dir, 4660 struct dentry *dentry, 4661 struct btrfs_key *location, 4662 struct btrfs_root **sub_root) 4663 { 4664 struct btrfs_path *path; 4665 struct btrfs_root *new_root; 4666 struct btrfs_root_ref *ref; 4667 struct extent_buffer *leaf; 4668 int ret; 4669 int err = 0; 4670 4671 path = btrfs_alloc_path(); 4672 if (!path) { 4673 err = -ENOMEM; 4674 goto out; 4675 } 4676 4677 err = -ENOENT; 4678 ret = btrfs_find_root_ref(root->fs_info->tree_root, path, 4679 BTRFS_I(dir)->root->root_key.objectid, 4680 location->objectid); 4681 if (ret) { 4682 if (ret < 0) 4683 err = ret; 4684 goto out; 4685 } 4686 4687 leaf = path->nodes[0]; 4688 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 4689 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || 4690 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 4691 goto out; 4692 4693 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 4694 (unsigned long)(ref + 1), 4695 dentry->d_name.len); 4696 if (ret) 4697 goto out; 4698 4699 btrfs_release_path(path); 4700 4701 new_root = btrfs_read_fs_root_no_name(root->fs_info, location); 4702 if (IS_ERR(new_root)) { 4703 err = PTR_ERR(new_root); 4704 goto out; 4705 } 4706 4707 *sub_root = new_root; 4708 location->objectid = btrfs_root_dirid(&new_root->root_item); 4709 location->type = BTRFS_INODE_ITEM_KEY; 4710 location->offset = 0; 4711 err = 0; 4712 out: 4713 btrfs_free_path(path); 4714 return err; 4715 } 4716 4717 static void inode_tree_add(struct inode *inode) 4718 { 4719 struct btrfs_root *root = BTRFS_I(inode)->root; 4720 struct btrfs_inode *entry; 4721 struct rb_node **p; 4722 struct rb_node *parent; 4723 u64 ino = btrfs_ino(inode); 4724 4725 if (inode_unhashed(inode)) 4726 return; 4727 again: 4728 parent = NULL; 4729 spin_lock(&root->inode_lock); 4730 p = &root->inode_tree.rb_node; 4731 while (*p) { 4732 parent = *p; 4733 entry = rb_entry(parent, struct btrfs_inode, rb_node); 4734 4735 if (ino < btrfs_ino(&entry->vfs_inode)) 4736 p = &parent->rb_left; 4737 else if (ino > btrfs_ino(&entry->vfs_inode)) 4738 p = &parent->rb_right; 4739 else { 4740 WARN_ON(!(entry->vfs_inode.i_state & 4741 (I_WILL_FREE | I_FREEING))); 4742 rb_erase(parent, &root->inode_tree); 4743 RB_CLEAR_NODE(parent); 4744 spin_unlock(&root->inode_lock); 4745 goto again; 4746 } 4747 } 4748 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p); 4749 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree); 4750 spin_unlock(&root->inode_lock); 4751 } 4752 4753 static void inode_tree_del(struct inode *inode) 4754 { 4755 struct btrfs_root *root = BTRFS_I(inode)->root; 4756 int empty = 0; 4757 4758 spin_lock(&root->inode_lock); 4759 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 4760 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 4761 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 4762 empty = RB_EMPTY_ROOT(&root->inode_tree); 4763 } 4764 spin_unlock(&root->inode_lock); 4765 4766 /* 4767 * Free space cache has inodes in the tree root, but the tree root has a 4768 * root_refs of 0, so this could end up dropping the tree root as a 4769 * snapshot, so we need the extra !root->fs_info->tree_root check to 4770 * make sure we don't drop it. 4771 */ 4772 if (empty && btrfs_root_refs(&root->root_item) == 0 && 4773 root != root->fs_info->tree_root) { 4774 synchronize_srcu(&root->fs_info->subvol_srcu); 4775 spin_lock(&root->inode_lock); 4776 empty = RB_EMPTY_ROOT(&root->inode_tree); 4777 spin_unlock(&root->inode_lock); 4778 if (empty) 4779 btrfs_add_dead_root(root); 4780 } 4781 } 4782 4783 void btrfs_invalidate_inodes(struct btrfs_root *root) 4784 { 4785 struct rb_node *node; 4786 struct rb_node *prev; 4787 struct btrfs_inode *entry; 4788 struct inode *inode; 4789 u64 objectid = 0; 4790 4791 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 4792 4793 spin_lock(&root->inode_lock); 4794 again: 4795 node = root->inode_tree.rb_node; 4796 prev = NULL; 4797 while (node) { 4798 prev = node; 4799 entry = rb_entry(node, struct btrfs_inode, rb_node); 4800 4801 if (objectid < btrfs_ino(&entry->vfs_inode)) 4802 node = node->rb_left; 4803 else if (objectid > btrfs_ino(&entry->vfs_inode)) 4804 node = node->rb_right; 4805 else 4806 break; 4807 } 4808 if (!node) { 4809 while (prev) { 4810 entry = rb_entry(prev, struct btrfs_inode, rb_node); 4811 if (objectid <= btrfs_ino(&entry->vfs_inode)) { 4812 node = prev; 4813 break; 4814 } 4815 prev = rb_next(prev); 4816 } 4817 } 4818 while (node) { 4819 entry = rb_entry(node, struct btrfs_inode, rb_node); 4820 objectid = btrfs_ino(&entry->vfs_inode) + 1; 4821 inode = igrab(&entry->vfs_inode); 4822 if (inode) { 4823 spin_unlock(&root->inode_lock); 4824 if (atomic_read(&inode->i_count) > 1) 4825 d_prune_aliases(inode); 4826 /* 4827 * btrfs_drop_inode will have it removed from 4828 * the inode cache when its usage count 4829 * hits zero. 4830 */ 4831 iput(inode); 4832 cond_resched(); 4833 spin_lock(&root->inode_lock); 4834 goto again; 4835 } 4836 4837 if (cond_resched_lock(&root->inode_lock)) 4838 goto again; 4839 4840 node = rb_next(node); 4841 } 4842 spin_unlock(&root->inode_lock); 4843 } 4844 4845 static int btrfs_init_locked_inode(struct inode *inode, void *p) 4846 { 4847 struct btrfs_iget_args *args = p; 4848 inode->i_ino = args->ino; 4849 BTRFS_I(inode)->root = args->root; 4850 return 0; 4851 } 4852 4853 static int btrfs_find_actor(struct inode *inode, void *opaque) 4854 { 4855 struct btrfs_iget_args *args = opaque; 4856 return args->ino == btrfs_ino(inode) && 4857 args->root == BTRFS_I(inode)->root; 4858 } 4859 4860 static struct inode *btrfs_iget_locked(struct super_block *s, 4861 u64 objectid, 4862 struct btrfs_root *root) 4863 { 4864 struct inode *inode; 4865 struct btrfs_iget_args args; 4866 args.ino = objectid; 4867 args.root = root; 4868 4869 inode = iget5_locked(s, objectid, btrfs_find_actor, 4870 btrfs_init_locked_inode, 4871 (void *)&args); 4872 return inode; 4873 } 4874 4875 /* Get an inode object given its location and corresponding root. 4876 * Returns in *is_new if the inode was read from disk 4877 */ 4878 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 4879 struct btrfs_root *root, int *new) 4880 { 4881 struct inode *inode; 4882 4883 inode = btrfs_iget_locked(s, location->objectid, root); 4884 if (!inode) 4885 return ERR_PTR(-ENOMEM); 4886 4887 if (inode->i_state & I_NEW) { 4888 BTRFS_I(inode)->root = root; 4889 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location)); 4890 btrfs_read_locked_inode(inode); 4891 if (!is_bad_inode(inode)) { 4892 inode_tree_add(inode); 4893 unlock_new_inode(inode); 4894 if (new) 4895 *new = 1; 4896 } else { 4897 unlock_new_inode(inode); 4898 iput(inode); 4899 inode = ERR_PTR(-ESTALE); 4900 } 4901 } 4902 4903 return inode; 4904 } 4905 4906 static struct inode *new_simple_dir(struct super_block *s, 4907 struct btrfs_key *key, 4908 struct btrfs_root *root) 4909 { 4910 struct inode *inode = new_inode(s); 4911 4912 if (!inode) 4913 return ERR_PTR(-ENOMEM); 4914 4915 BTRFS_I(inode)->root = root; 4916 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 4917 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 4918 4919 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 4920 inode->i_op = &btrfs_dir_ro_inode_operations; 4921 inode->i_fop = &simple_dir_operations; 4922 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 4923 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 4924 4925 return inode; 4926 } 4927 4928 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 4929 { 4930 struct inode *inode; 4931 struct btrfs_root *root = BTRFS_I(dir)->root; 4932 struct btrfs_root *sub_root = root; 4933 struct btrfs_key location; 4934 int index; 4935 int ret = 0; 4936 4937 if (dentry->d_name.len > BTRFS_NAME_LEN) 4938 return ERR_PTR(-ENAMETOOLONG); 4939 4940 ret = btrfs_inode_by_name(dir, dentry, &location); 4941 if (ret < 0) 4942 return ERR_PTR(ret); 4943 4944 if (location.objectid == 0) 4945 return NULL; 4946 4947 if (location.type == BTRFS_INODE_ITEM_KEY) { 4948 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 4949 return inode; 4950 } 4951 4952 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 4953 4954 index = srcu_read_lock(&root->fs_info->subvol_srcu); 4955 ret = fixup_tree_root_location(root, dir, dentry, 4956 &location, &sub_root); 4957 if (ret < 0) { 4958 if (ret != -ENOENT) 4959 inode = ERR_PTR(ret); 4960 else 4961 inode = new_simple_dir(dir->i_sb, &location, sub_root); 4962 } else { 4963 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 4964 } 4965 srcu_read_unlock(&root->fs_info->subvol_srcu, index); 4966 4967 if (!IS_ERR(inode) && root != sub_root) { 4968 down_read(&root->fs_info->cleanup_work_sem); 4969 if (!(inode->i_sb->s_flags & MS_RDONLY)) 4970 ret = btrfs_orphan_cleanup(sub_root); 4971 up_read(&root->fs_info->cleanup_work_sem); 4972 if (ret) { 4973 iput(inode); 4974 inode = ERR_PTR(ret); 4975 } 4976 } 4977 4978 return inode; 4979 } 4980 4981 static int btrfs_dentry_delete(const struct dentry *dentry) 4982 { 4983 struct btrfs_root *root; 4984 struct inode *inode = dentry->d_inode; 4985 4986 if (!inode && !IS_ROOT(dentry)) 4987 inode = dentry->d_parent->d_inode; 4988 4989 if (inode) { 4990 root = BTRFS_I(inode)->root; 4991 if (btrfs_root_refs(&root->root_item) == 0) 4992 return 1; 4993 4994 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 4995 return 1; 4996 } 4997 return 0; 4998 } 4999 5000 static void btrfs_dentry_release(struct dentry *dentry) 5001 { 5002 if (dentry->d_fsdata) 5003 kfree(dentry->d_fsdata); 5004 } 5005 5006 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5007 unsigned int flags) 5008 { 5009 struct dentry *ret; 5010 5011 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry); 5012 return ret; 5013 } 5014 5015 unsigned char btrfs_filetype_table[] = { 5016 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5017 }; 5018 5019 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) 5020 { 5021 struct inode *inode = file_inode(file); 5022 struct btrfs_root *root = BTRFS_I(inode)->root; 5023 struct btrfs_item *item; 5024 struct btrfs_dir_item *di; 5025 struct btrfs_key key; 5026 struct btrfs_key found_key; 5027 struct btrfs_path *path; 5028 struct list_head ins_list; 5029 struct list_head del_list; 5030 int ret; 5031 struct extent_buffer *leaf; 5032 int slot; 5033 unsigned char d_type; 5034 int over = 0; 5035 u32 di_cur; 5036 u32 di_total; 5037 u32 di_len; 5038 int key_type = BTRFS_DIR_INDEX_KEY; 5039 char tmp_name[32]; 5040 char *name_ptr; 5041 int name_len; 5042 int is_curr = 0; /* ctx->pos points to the current index? */ 5043 5044 /* FIXME, use a real flag for deciding about the key type */ 5045 if (root->fs_info->tree_root == root) 5046 key_type = BTRFS_DIR_ITEM_KEY; 5047 5048 if (!dir_emit_dots(file, ctx)) 5049 return 0; 5050 5051 path = btrfs_alloc_path(); 5052 if (!path) 5053 return -ENOMEM; 5054 5055 path->reada = 1; 5056 5057 if (key_type == BTRFS_DIR_INDEX_KEY) { 5058 INIT_LIST_HEAD(&ins_list); 5059 INIT_LIST_HEAD(&del_list); 5060 btrfs_get_delayed_items(inode, &ins_list, &del_list); 5061 } 5062 5063 btrfs_set_key_type(&key, key_type); 5064 key.offset = ctx->pos; 5065 key.objectid = btrfs_ino(inode); 5066 5067 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5068 if (ret < 0) 5069 goto err; 5070 5071 while (1) { 5072 leaf = path->nodes[0]; 5073 slot = path->slots[0]; 5074 if (slot >= btrfs_header_nritems(leaf)) { 5075 ret = btrfs_next_leaf(root, path); 5076 if (ret < 0) 5077 goto err; 5078 else if (ret > 0) 5079 break; 5080 continue; 5081 } 5082 5083 item = btrfs_item_nr(leaf, slot); 5084 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5085 5086 if (found_key.objectid != key.objectid) 5087 break; 5088 if (btrfs_key_type(&found_key) != key_type) 5089 break; 5090 if (found_key.offset < ctx->pos) 5091 goto next; 5092 if (key_type == BTRFS_DIR_INDEX_KEY && 5093 btrfs_should_delete_dir_index(&del_list, 5094 found_key.offset)) 5095 goto next; 5096 5097 ctx->pos = found_key.offset; 5098 is_curr = 1; 5099 5100 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5101 di_cur = 0; 5102 di_total = btrfs_item_size(leaf, item); 5103 5104 while (di_cur < di_total) { 5105 struct btrfs_key location; 5106 5107 if (verify_dir_item(root, leaf, di)) 5108 break; 5109 5110 name_len = btrfs_dir_name_len(leaf, di); 5111 if (name_len <= sizeof(tmp_name)) { 5112 name_ptr = tmp_name; 5113 } else { 5114 name_ptr = kmalloc(name_len, GFP_NOFS); 5115 if (!name_ptr) { 5116 ret = -ENOMEM; 5117 goto err; 5118 } 5119 } 5120 read_extent_buffer(leaf, name_ptr, 5121 (unsigned long)(di + 1), name_len); 5122 5123 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5124 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5125 5126 5127 /* is this a reference to our own snapshot? If so 5128 * skip it. 5129 * 5130 * In contrast to old kernels, we insert the snapshot's 5131 * dir item and dir index after it has been created, so 5132 * we won't find a reference to our own snapshot. We 5133 * still keep the following code for backward 5134 * compatibility. 5135 */ 5136 if (location.type == BTRFS_ROOT_ITEM_KEY && 5137 location.objectid == root->root_key.objectid) { 5138 over = 0; 5139 goto skip; 5140 } 5141 over = !dir_emit(ctx, name_ptr, name_len, 5142 location.objectid, d_type); 5143 5144 skip: 5145 if (name_ptr != tmp_name) 5146 kfree(name_ptr); 5147 5148 if (over) 5149 goto nopos; 5150 di_len = btrfs_dir_name_len(leaf, di) + 5151 btrfs_dir_data_len(leaf, di) + sizeof(*di); 5152 di_cur += di_len; 5153 di = (struct btrfs_dir_item *)((char *)di + di_len); 5154 } 5155 next: 5156 path->slots[0]++; 5157 } 5158 5159 if (key_type == BTRFS_DIR_INDEX_KEY) { 5160 if (is_curr) 5161 ctx->pos++; 5162 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); 5163 if (ret) 5164 goto nopos; 5165 } 5166 5167 /* Reached end of directory/root. Bump pos past the last item. */ 5168 if (key_type == BTRFS_DIR_INDEX_KEY) 5169 /* 5170 * 32-bit glibc will use getdents64, but then strtol - 5171 * so the last number we can serve is this. 5172 */ 5173 ctx->pos = 0x7fffffff; 5174 else 5175 ctx->pos++; 5176 nopos: 5177 ret = 0; 5178 err: 5179 if (key_type == BTRFS_DIR_INDEX_KEY) 5180 btrfs_put_delayed_items(&ins_list, &del_list); 5181 btrfs_free_path(path); 5182 return ret; 5183 } 5184 5185 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5186 { 5187 struct btrfs_root *root = BTRFS_I(inode)->root; 5188 struct btrfs_trans_handle *trans; 5189 int ret = 0; 5190 bool nolock = false; 5191 5192 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5193 return 0; 5194 5195 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) 5196 nolock = true; 5197 5198 if (wbc->sync_mode == WB_SYNC_ALL) { 5199 if (nolock) 5200 trans = btrfs_join_transaction_nolock(root); 5201 else 5202 trans = btrfs_join_transaction(root); 5203 if (IS_ERR(trans)) 5204 return PTR_ERR(trans); 5205 ret = btrfs_commit_transaction(trans, root); 5206 } 5207 return ret; 5208 } 5209 5210 /* 5211 * This is somewhat expensive, updating the tree every time the 5212 * inode changes. But, it is most likely to find the inode in cache. 5213 * FIXME, needs more benchmarking...there are no reasons other than performance 5214 * to keep or drop this code. 5215 */ 5216 static int btrfs_dirty_inode(struct inode *inode) 5217 { 5218 struct btrfs_root *root = BTRFS_I(inode)->root; 5219 struct btrfs_trans_handle *trans; 5220 int ret; 5221 5222 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5223 return 0; 5224 5225 trans = btrfs_join_transaction(root); 5226 if (IS_ERR(trans)) 5227 return PTR_ERR(trans); 5228 5229 ret = btrfs_update_inode(trans, root, inode); 5230 if (ret && ret == -ENOSPC) { 5231 /* whoops, lets try again with the full transaction */ 5232 btrfs_end_transaction(trans, root); 5233 trans = btrfs_start_transaction(root, 1); 5234 if (IS_ERR(trans)) 5235 return PTR_ERR(trans); 5236 5237 ret = btrfs_update_inode(trans, root, inode); 5238 } 5239 btrfs_end_transaction(trans, root); 5240 if (BTRFS_I(inode)->delayed_node) 5241 btrfs_balance_delayed_items(root); 5242 5243 return ret; 5244 } 5245 5246 /* 5247 * This is a copy of file_update_time. We need this so we can return error on 5248 * ENOSPC for updating the inode in the case of file write and mmap writes. 5249 */ 5250 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5251 int flags) 5252 { 5253 struct btrfs_root *root = BTRFS_I(inode)->root; 5254 5255 if (btrfs_root_readonly(root)) 5256 return -EROFS; 5257 5258 if (flags & S_VERSION) 5259 inode_inc_iversion(inode); 5260 if (flags & S_CTIME) 5261 inode->i_ctime = *now; 5262 if (flags & S_MTIME) 5263 inode->i_mtime = *now; 5264 if (flags & S_ATIME) 5265 inode->i_atime = *now; 5266 return btrfs_dirty_inode(inode); 5267 } 5268 5269 /* 5270 * find the highest existing sequence number in a directory 5271 * and then set the in-memory index_cnt variable to reflect 5272 * free sequence numbers 5273 */ 5274 static int btrfs_set_inode_index_count(struct inode *inode) 5275 { 5276 struct btrfs_root *root = BTRFS_I(inode)->root; 5277 struct btrfs_key key, found_key; 5278 struct btrfs_path *path; 5279 struct extent_buffer *leaf; 5280 int ret; 5281 5282 key.objectid = btrfs_ino(inode); 5283 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); 5284 key.offset = (u64)-1; 5285 5286 path = btrfs_alloc_path(); 5287 if (!path) 5288 return -ENOMEM; 5289 5290 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5291 if (ret < 0) 5292 goto out; 5293 /* FIXME: we should be able to handle this */ 5294 if (ret == 0) 5295 goto out; 5296 ret = 0; 5297 5298 /* 5299 * MAGIC NUMBER EXPLANATION: 5300 * since we search a directory based on f_pos we have to start at 2 5301 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 5302 * else has to start at 2 5303 */ 5304 if (path->slots[0] == 0) { 5305 BTRFS_I(inode)->index_cnt = 2; 5306 goto out; 5307 } 5308 5309 path->slots[0]--; 5310 5311 leaf = path->nodes[0]; 5312 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5313 5314 if (found_key.objectid != btrfs_ino(inode) || 5315 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) { 5316 BTRFS_I(inode)->index_cnt = 2; 5317 goto out; 5318 } 5319 5320 BTRFS_I(inode)->index_cnt = found_key.offset + 1; 5321 out: 5322 btrfs_free_path(path); 5323 return ret; 5324 } 5325 5326 /* 5327 * helper to find a free sequence number in a given directory. This current 5328 * code is very simple, later versions will do smarter things in the btree 5329 */ 5330 int btrfs_set_inode_index(struct inode *dir, u64 *index) 5331 { 5332 int ret = 0; 5333 5334 if (BTRFS_I(dir)->index_cnt == (u64)-1) { 5335 ret = btrfs_inode_delayed_dir_index_count(dir); 5336 if (ret) { 5337 ret = btrfs_set_inode_index_count(dir); 5338 if (ret) 5339 return ret; 5340 } 5341 } 5342 5343 *index = BTRFS_I(dir)->index_cnt; 5344 BTRFS_I(dir)->index_cnt++; 5345 5346 return ret; 5347 } 5348 5349 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 5350 struct btrfs_root *root, 5351 struct inode *dir, 5352 const char *name, int name_len, 5353 u64 ref_objectid, u64 objectid, 5354 umode_t mode, u64 *index) 5355 { 5356 struct inode *inode; 5357 struct btrfs_inode_item *inode_item; 5358 struct btrfs_key *location; 5359 struct btrfs_path *path; 5360 struct btrfs_inode_ref *ref; 5361 struct btrfs_key key[2]; 5362 u32 sizes[2]; 5363 unsigned long ptr; 5364 int ret; 5365 int owner; 5366 5367 path = btrfs_alloc_path(); 5368 if (!path) 5369 return ERR_PTR(-ENOMEM); 5370 5371 inode = new_inode(root->fs_info->sb); 5372 if (!inode) { 5373 btrfs_free_path(path); 5374 return ERR_PTR(-ENOMEM); 5375 } 5376 5377 /* 5378 * we have to initialize this early, so we can reclaim the inode 5379 * number if we fail afterwards in this function. 5380 */ 5381 inode->i_ino = objectid; 5382 5383 if (dir) { 5384 trace_btrfs_inode_request(dir); 5385 5386 ret = btrfs_set_inode_index(dir, index); 5387 if (ret) { 5388 btrfs_free_path(path); 5389 iput(inode); 5390 return ERR_PTR(ret); 5391 } 5392 } 5393 /* 5394 * index_cnt is ignored for everything but a dir, 5395 * btrfs_get_inode_index_count has an explanation for the magic 5396 * number 5397 */ 5398 BTRFS_I(inode)->index_cnt = 2; 5399 BTRFS_I(inode)->root = root; 5400 BTRFS_I(inode)->generation = trans->transid; 5401 inode->i_generation = BTRFS_I(inode)->generation; 5402 5403 /* 5404 * We could have gotten an inode number from somebody who was fsynced 5405 * and then removed in this same transaction, so let's just set full 5406 * sync since it will be a full sync anyway and this will blow away the 5407 * old info in the log. 5408 */ 5409 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 5410 5411 if (S_ISDIR(mode)) 5412 owner = 0; 5413 else 5414 owner = 1; 5415 5416 key[0].objectid = objectid; 5417 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY); 5418 key[0].offset = 0; 5419 5420 /* 5421 * Start new inodes with an inode_ref. This is slightly more 5422 * efficient for small numbers of hard links since they will 5423 * be packed into one item. Extended refs will kick in if we 5424 * add more hard links than can fit in the ref item. 5425 */ 5426 key[1].objectid = objectid; 5427 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); 5428 key[1].offset = ref_objectid; 5429 5430 sizes[0] = sizeof(struct btrfs_inode_item); 5431 sizes[1] = name_len + sizeof(*ref); 5432 5433 path->leave_spinning = 1; 5434 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2); 5435 if (ret != 0) 5436 goto fail; 5437 5438 inode_init_owner(inode, dir, mode); 5439 inode_set_bytes(inode, 0); 5440 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5441 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 5442 struct btrfs_inode_item); 5443 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, 5444 sizeof(*inode_item)); 5445 fill_inode_item(trans, path->nodes[0], inode_item, inode); 5446 5447 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 5448 struct btrfs_inode_ref); 5449 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 5450 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 5451 ptr = (unsigned long)(ref + 1); 5452 write_extent_buffer(path->nodes[0], name, ptr, name_len); 5453 5454 btrfs_mark_buffer_dirty(path->nodes[0]); 5455 btrfs_free_path(path); 5456 5457 location = &BTRFS_I(inode)->location; 5458 location->objectid = objectid; 5459 location->offset = 0; 5460 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); 5461 5462 btrfs_inherit_iflags(inode, dir); 5463 5464 if (S_ISREG(mode)) { 5465 if (btrfs_test_opt(root, NODATASUM)) 5466 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 5467 if (btrfs_test_opt(root, NODATACOW)) 5468 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 5469 BTRFS_INODE_NODATASUM; 5470 } 5471 5472 insert_inode_hash(inode); 5473 inode_tree_add(inode); 5474 5475 trace_btrfs_inode_new(inode); 5476 btrfs_set_inode_last_trans(trans, inode); 5477 5478 btrfs_update_root_times(trans, root); 5479 5480 return inode; 5481 fail: 5482 if (dir) 5483 BTRFS_I(dir)->index_cnt--; 5484 btrfs_free_path(path); 5485 iput(inode); 5486 return ERR_PTR(ret); 5487 } 5488 5489 static inline u8 btrfs_inode_type(struct inode *inode) 5490 { 5491 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 5492 } 5493 5494 /* 5495 * utility function to add 'inode' into 'parent_inode' with 5496 * a give name and a given sequence number. 5497 * if 'add_backref' is true, also insert a backref from the 5498 * inode to the parent directory. 5499 */ 5500 int btrfs_add_link(struct btrfs_trans_handle *trans, 5501 struct inode *parent_inode, struct inode *inode, 5502 const char *name, int name_len, int add_backref, u64 index) 5503 { 5504 int ret = 0; 5505 struct btrfs_key key; 5506 struct btrfs_root *root = BTRFS_I(parent_inode)->root; 5507 u64 ino = btrfs_ino(inode); 5508 u64 parent_ino = btrfs_ino(parent_inode); 5509 5510 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5511 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); 5512 } else { 5513 key.objectid = ino; 5514 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); 5515 key.offset = 0; 5516 } 5517 5518 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5519 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 5520 key.objectid, root->root_key.objectid, 5521 parent_ino, index, name, name_len); 5522 } else if (add_backref) { 5523 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 5524 parent_ino, index); 5525 } 5526 5527 /* Nothing to clean up yet */ 5528 if (ret) 5529 return ret; 5530 5531 ret = btrfs_insert_dir_item(trans, root, name, name_len, 5532 parent_inode, &key, 5533 btrfs_inode_type(inode), index); 5534 if (ret == -EEXIST || ret == -EOVERFLOW) 5535 goto fail_dir_item; 5536 else if (ret) { 5537 btrfs_abort_transaction(trans, root, ret); 5538 return ret; 5539 } 5540 5541 btrfs_i_size_write(parent_inode, parent_inode->i_size + 5542 name_len * 2); 5543 inode_inc_iversion(parent_inode); 5544 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 5545 ret = btrfs_update_inode(trans, root, parent_inode); 5546 if (ret) 5547 btrfs_abort_transaction(trans, root, ret); 5548 return ret; 5549 5550 fail_dir_item: 5551 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5552 u64 local_index; 5553 int err; 5554 err = btrfs_del_root_ref(trans, root->fs_info->tree_root, 5555 key.objectid, root->root_key.objectid, 5556 parent_ino, &local_index, name, name_len); 5557 5558 } else if (add_backref) { 5559 u64 local_index; 5560 int err; 5561 5562 err = btrfs_del_inode_ref(trans, root, name, name_len, 5563 ino, parent_ino, &local_index); 5564 } 5565 return ret; 5566 } 5567 5568 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 5569 struct inode *dir, struct dentry *dentry, 5570 struct inode *inode, int backref, u64 index) 5571 { 5572 int err = btrfs_add_link(trans, dir, inode, 5573 dentry->d_name.name, dentry->d_name.len, 5574 backref, index); 5575 if (err > 0) 5576 err = -EEXIST; 5577 return err; 5578 } 5579 5580 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 5581 umode_t mode, dev_t rdev) 5582 { 5583 struct btrfs_trans_handle *trans; 5584 struct btrfs_root *root = BTRFS_I(dir)->root; 5585 struct inode *inode = NULL; 5586 int err; 5587 int drop_inode = 0; 5588 u64 objectid; 5589 u64 index = 0; 5590 5591 if (!new_valid_dev(rdev)) 5592 return -EINVAL; 5593 5594 /* 5595 * 2 for inode item and ref 5596 * 2 for dir items 5597 * 1 for xattr if selinux is on 5598 */ 5599 trans = btrfs_start_transaction(root, 5); 5600 if (IS_ERR(trans)) 5601 return PTR_ERR(trans); 5602 5603 err = btrfs_find_free_ino(root, &objectid); 5604 if (err) 5605 goto out_unlock; 5606 5607 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5608 dentry->d_name.len, btrfs_ino(dir), objectid, 5609 mode, &index); 5610 if (IS_ERR(inode)) { 5611 err = PTR_ERR(inode); 5612 goto out_unlock; 5613 } 5614 5615 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5616 if (err) { 5617 drop_inode = 1; 5618 goto out_unlock; 5619 } 5620 5621 /* 5622 * If the active LSM wants to access the inode during 5623 * d_instantiate it needs these. Smack checks to see 5624 * if the filesystem supports xattrs by looking at the 5625 * ops vector. 5626 */ 5627 5628 inode->i_op = &btrfs_special_inode_operations; 5629 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5630 if (err) 5631 drop_inode = 1; 5632 else { 5633 init_special_inode(inode, inode->i_mode, rdev); 5634 btrfs_update_inode(trans, root, inode); 5635 d_instantiate(dentry, inode); 5636 } 5637 out_unlock: 5638 btrfs_end_transaction(trans, root); 5639 btrfs_btree_balance_dirty(root); 5640 if (drop_inode) { 5641 inode_dec_link_count(inode); 5642 iput(inode); 5643 } 5644 return err; 5645 } 5646 5647 static int btrfs_create(struct inode *dir, struct dentry *dentry, 5648 umode_t mode, bool excl) 5649 { 5650 struct btrfs_trans_handle *trans; 5651 struct btrfs_root *root = BTRFS_I(dir)->root; 5652 struct inode *inode = NULL; 5653 int drop_inode_on_err = 0; 5654 int err; 5655 u64 objectid; 5656 u64 index = 0; 5657 5658 /* 5659 * 2 for inode item and ref 5660 * 2 for dir items 5661 * 1 for xattr if selinux is on 5662 */ 5663 trans = btrfs_start_transaction(root, 5); 5664 if (IS_ERR(trans)) 5665 return PTR_ERR(trans); 5666 5667 err = btrfs_find_free_ino(root, &objectid); 5668 if (err) 5669 goto out_unlock; 5670 5671 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5672 dentry->d_name.len, btrfs_ino(dir), objectid, 5673 mode, &index); 5674 if (IS_ERR(inode)) { 5675 err = PTR_ERR(inode); 5676 goto out_unlock; 5677 } 5678 drop_inode_on_err = 1; 5679 5680 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5681 if (err) 5682 goto out_unlock; 5683 5684 err = btrfs_update_inode(trans, root, inode); 5685 if (err) 5686 goto out_unlock; 5687 5688 /* 5689 * If the active LSM wants to access the inode during 5690 * d_instantiate it needs these. Smack checks to see 5691 * if the filesystem supports xattrs by looking at the 5692 * ops vector. 5693 */ 5694 inode->i_fop = &btrfs_file_operations; 5695 inode->i_op = &btrfs_file_inode_operations; 5696 5697 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5698 if (err) 5699 goto out_unlock; 5700 5701 inode->i_mapping->a_ops = &btrfs_aops; 5702 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 5703 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 5704 d_instantiate(dentry, inode); 5705 5706 out_unlock: 5707 btrfs_end_transaction(trans, root); 5708 if (err && drop_inode_on_err) { 5709 inode_dec_link_count(inode); 5710 iput(inode); 5711 } 5712 btrfs_btree_balance_dirty(root); 5713 return err; 5714 } 5715 5716 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 5717 struct dentry *dentry) 5718 { 5719 struct btrfs_trans_handle *trans; 5720 struct btrfs_root *root = BTRFS_I(dir)->root; 5721 struct inode *inode = old_dentry->d_inode; 5722 u64 index; 5723 int err; 5724 int drop_inode = 0; 5725 5726 /* do not allow sys_link's with other subvols of the same device */ 5727 if (root->objectid != BTRFS_I(inode)->root->objectid) 5728 return -EXDEV; 5729 5730 if (inode->i_nlink >= BTRFS_LINK_MAX) 5731 return -EMLINK; 5732 5733 err = btrfs_set_inode_index(dir, &index); 5734 if (err) 5735 goto fail; 5736 5737 /* 5738 * 2 items for inode and inode ref 5739 * 2 items for dir items 5740 * 1 item for parent inode 5741 */ 5742 trans = btrfs_start_transaction(root, 5); 5743 if (IS_ERR(trans)) { 5744 err = PTR_ERR(trans); 5745 goto fail; 5746 } 5747 5748 btrfs_inc_nlink(inode); 5749 inode_inc_iversion(inode); 5750 inode->i_ctime = CURRENT_TIME; 5751 ihold(inode); 5752 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 5753 5754 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); 5755 5756 if (err) { 5757 drop_inode = 1; 5758 } else { 5759 struct dentry *parent = dentry->d_parent; 5760 err = btrfs_update_inode(trans, root, inode); 5761 if (err) 5762 goto fail; 5763 d_instantiate(dentry, inode); 5764 btrfs_log_new_name(trans, inode, NULL, parent); 5765 } 5766 5767 btrfs_end_transaction(trans, root); 5768 fail: 5769 if (drop_inode) { 5770 inode_dec_link_count(inode); 5771 iput(inode); 5772 } 5773 btrfs_btree_balance_dirty(root); 5774 return err; 5775 } 5776 5777 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 5778 { 5779 struct inode *inode = NULL; 5780 struct btrfs_trans_handle *trans; 5781 struct btrfs_root *root = BTRFS_I(dir)->root; 5782 int err = 0; 5783 int drop_on_err = 0; 5784 u64 objectid = 0; 5785 u64 index = 0; 5786 5787 /* 5788 * 2 items for inode and ref 5789 * 2 items for dir items 5790 * 1 for xattr if selinux is on 5791 */ 5792 trans = btrfs_start_transaction(root, 5); 5793 if (IS_ERR(trans)) 5794 return PTR_ERR(trans); 5795 5796 err = btrfs_find_free_ino(root, &objectid); 5797 if (err) 5798 goto out_fail; 5799 5800 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5801 dentry->d_name.len, btrfs_ino(dir), objectid, 5802 S_IFDIR | mode, &index); 5803 if (IS_ERR(inode)) { 5804 err = PTR_ERR(inode); 5805 goto out_fail; 5806 } 5807 5808 drop_on_err = 1; 5809 5810 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5811 if (err) 5812 goto out_fail; 5813 5814 inode->i_op = &btrfs_dir_inode_operations; 5815 inode->i_fop = &btrfs_dir_file_operations; 5816 5817 btrfs_i_size_write(inode, 0); 5818 err = btrfs_update_inode(trans, root, inode); 5819 if (err) 5820 goto out_fail; 5821 5822 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, 5823 dentry->d_name.len, 0, index); 5824 if (err) 5825 goto out_fail; 5826 5827 d_instantiate(dentry, inode); 5828 drop_on_err = 0; 5829 5830 out_fail: 5831 btrfs_end_transaction(trans, root); 5832 if (drop_on_err) 5833 iput(inode); 5834 btrfs_btree_balance_dirty(root); 5835 return err; 5836 } 5837 5838 /* helper for btfs_get_extent. Given an existing extent in the tree, 5839 * and an extent that you want to insert, deal with overlap and insert 5840 * the new extent into the tree. 5841 */ 5842 static int merge_extent_mapping(struct extent_map_tree *em_tree, 5843 struct extent_map *existing, 5844 struct extent_map *em, 5845 u64 map_start, u64 map_len) 5846 { 5847 u64 start_diff; 5848 5849 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 5850 start_diff = map_start - em->start; 5851 em->start = map_start; 5852 em->len = map_len; 5853 if (em->block_start < EXTENT_MAP_LAST_BYTE && 5854 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 5855 em->block_start += start_diff; 5856 em->block_len -= start_diff; 5857 } 5858 return add_extent_mapping(em_tree, em, 0); 5859 } 5860 5861 static noinline int uncompress_inline(struct btrfs_path *path, 5862 struct inode *inode, struct page *page, 5863 size_t pg_offset, u64 extent_offset, 5864 struct btrfs_file_extent_item *item) 5865 { 5866 int ret; 5867 struct extent_buffer *leaf = path->nodes[0]; 5868 char *tmp; 5869 size_t max_size; 5870 unsigned long inline_size; 5871 unsigned long ptr; 5872 int compress_type; 5873 5874 WARN_ON(pg_offset != 0); 5875 compress_type = btrfs_file_extent_compression(leaf, item); 5876 max_size = btrfs_file_extent_ram_bytes(leaf, item); 5877 inline_size = btrfs_file_extent_inline_item_len(leaf, 5878 btrfs_item_nr(leaf, path->slots[0])); 5879 tmp = kmalloc(inline_size, GFP_NOFS); 5880 if (!tmp) 5881 return -ENOMEM; 5882 ptr = btrfs_file_extent_inline_start(item); 5883 5884 read_extent_buffer(leaf, tmp, ptr, inline_size); 5885 5886 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); 5887 ret = btrfs_decompress(compress_type, tmp, page, 5888 extent_offset, inline_size, max_size); 5889 if (ret) { 5890 char *kaddr = kmap_atomic(page); 5891 unsigned long copy_size = min_t(u64, 5892 PAGE_CACHE_SIZE - pg_offset, 5893 max_size - extent_offset); 5894 memset(kaddr + pg_offset, 0, copy_size); 5895 kunmap_atomic(kaddr); 5896 } 5897 kfree(tmp); 5898 return 0; 5899 } 5900 5901 /* 5902 * a bit scary, this does extent mapping from logical file offset to the disk. 5903 * the ugly parts come from merging extents from the disk with the in-ram 5904 * representation. This gets more complex because of the data=ordered code, 5905 * where the in-ram extents might be locked pending data=ordered completion. 5906 * 5907 * This also copies inline extents directly into the page. 5908 */ 5909 5910 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 5911 size_t pg_offset, u64 start, u64 len, 5912 int create) 5913 { 5914 int ret; 5915 int err = 0; 5916 u64 bytenr; 5917 u64 extent_start = 0; 5918 u64 extent_end = 0; 5919 u64 objectid = btrfs_ino(inode); 5920 u32 found_type; 5921 struct btrfs_path *path = NULL; 5922 struct btrfs_root *root = BTRFS_I(inode)->root; 5923 struct btrfs_file_extent_item *item; 5924 struct extent_buffer *leaf; 5925 struct btrfs_key found_key; 5926 struct extent_map *em = NULL; 5927 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 5928 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 5929 struct btrfs_trans_handle *trans = NULL; 5930 int compress_type; 5931 5932 again: 5933 read_lock(&em_tree->lock); 5934 em = lookup_extent_mapping(em_tree, start, len); 5935 if (em) 5936 em->bdev = root->fs_info->fs_devices->latest_bdev; 5937 read_unlock(&em_tree->lock); 5938 5939 if (em) { 5940 if (em->start > start || em->start + em->len <= start) 5941 free_extent_map(em); 5942 else if (em->block_start == EXTENT_MAP_INLINE && page) 5943 free_extent_map(em); 5944 else 5945 goto out; 5946 } 5947 em = alloc_extent_map(); 5948 if (!em) { 5949 err = -ENOMEM; 5950 goto out; 5951 } 5952 em->bdev = root->fs_info->fs_devices->latest_bdev; 5953 em->start = EXTENT_MAP_HOLE; 5954 em->orig_start = EXTENT_MAP_HOLE; 5955 em->len = (u64)-1; 5956 em->block_len = (u64)-1; 5957 5958 if (!path) { 5959 path = btrfs_alloc_path(); 5960 if (!path) { 5961 err = -ENOMEM; 5962 goto out; 5963 } 5964 /* 5965 * Chances are we'll be called again, so go ahead and do 5966 * readahead 5967 */ 5968 path->reada = 1; 5969 } 5970 5971 ret = btrfs_lookup_file_extent(trans, root, path, 5972 objectid, start, trans != NULL); 5973 if (ret < 0) { 5974 err = ret; 5975 goto out; 5976 } 5977 5978 if (ret != 0) { 5979 if (path->slots[0] == 0) 5980 goto not_found; 5981 path->slots[0]--; 5982 } 5983 5984 leaf = path->nodes[0]; 5985 item = btrfs_item_ptr(leaf, path->slots[0], 5986 struct btrfs_file_extent_item); 5987 /* are we inside the extent that was found? */ 5988 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5989 found_type = btrfs_key_type(&found_key); 5990 if (found_key.objectid != objectid || 5991 found_type != BTRFS_EXTENT_DATA_KEY) { 5992 goto not_found; 5993 } 5994 5995 found_type = btrfs_file_extent_type(leaf, item); 5996 extent_start = found_key.offset; 5997 compress_type = btrfs_file_extent_compression(leaf, item); 5998 if (found_type == BTRFS_FILE_EXTENT_REG || 5999 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6000 extent_end = extent_start + 6001 btrfs_file_extent_num_bytes(leaf, item); 6002 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6003 size_t size; 6004 size = btrfs_file_extent_inline_len(leaf, item); 6005 extent_end = ALIGN(extent_start + size, root->sectorsize); 6006 } 6007 6008 if (start >= extent_end) { 6009 path->slots[0]++; 6010 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6011 ret = btrfs_next_leaf(root, path); 6012 if (ret < 0) { 6013 err = ret; 6014 goto out; 6015 } 6016 if (ret > 0) 6017 goto not_found; 6018 leaf = path->nodes[0]; 6019 } 6020 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6021 if (found_key.objectid != objectid || 6022 found_key.type != BTRFS_EXTENT_DATA_KEY) 6023 goto not_found; 6024 if (start + len <= found_key.offset) 6025 goto not_found; 6026 em->start = start; 6027 em->orig_start = start; 6028 em->len = found_key.offset - start; 6029 goto not_found_em; 6030 } 6031 6032 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item); 6033 if (found_type == BTRFS_FILE_EXTENT_REG || 6034 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6035 em->start = extent_start; 6036 em->len = extent_end - extent_start; 6037 em->orig_start = extent_start - 6038 btrfs_file_extent_offset(leaf, item); 6039 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, 6040 item); 6041 bytenr = btrfs_file_extent_disk_bytenr(leaf, item); 6042 if (bytenr == 0) { 6043 em->block_start = EXTENT_MAP_HOLE; 6044 goto insert; 6045 } 6046 if (compress_type != BTRFS_COMPRESS_NONE) { 6047 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6048 em->compress_type = compress_type; 6049 em->block_start = bytenr; 6050 em->block_len = em->orig_block_len; 6051 } else { 6052 bytenr += btrfs_file_extent_offset(leaf, item); 6053 em->block_start = bytenr; 6054 em->block_len = em->len; 6055 if (found_type == BTRFS_FILE_EXTENT_PREALLOC) 6056 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6057 } 6058 goto insert; 6059 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6060 unsigned long ptr; 6061 char *map; 6062 size_t size; 6063 size_t extent_offset; 6064 size_t copy_size; 6065 6066 em->block_start = EXTENT_MAP_INLINE; 6067 if (!page || create) { 6068 em->start = extent_start; 6069 em->len = extent_end - extent_start; 6070 goto out; 6071 } 6072 6073 size = btrfs_file_extent_inline_len(leaf, item); 6074 extent_offset = page_offset(page) + pg_offset - extent_start; 6075 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, 6076 size - extent_offset); 6077 em->start = extent_start + extent_offset; 6078 em->len = ALIGN(copy_size, root->sectorsize); 6079 em->orig_block_len = em->len; 6080 em->orig_start = em->start; 6081 if (compress_type) { 6082 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6083 em->compress_type = compress_type; 6084 } 6085 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6086 if (create == 0 && !PageUptodate(page)) { 6087 if (btrfs_file_extent_compression(leaf, item) != 6088 BTRFS_COMPRESS_NONE) { 6089 ret = uncompress_inline(path, inode, page, 6090 pg_offset, 6091 extent_offset, item); 6092 BUG_ON(ret); /* -ENOMEM */ 6093 } else { 6094 map = kmap(page); 6095 read_extent_buffer(leaf, map + pg_offset, ptr, 6096 copy_size); 6097 if (pg_offset + copy_size < PAGE_CACHE_SIZE) { 6098 memset(map + pg_offset + copy_size, 0, 6099 PAGE_CACHE_SIZE - pg_offset - 6100 copy_size); 6101 } 6102 kunmap(page); 6103 } 6104 flush_dcache_page(page); 6105 } else if (create && PageUptodate(page)) { 6106 BUG(); 6107 if (!trans) { 6108 kunmap(page); 6109 free_extent_map(em); 6110 em = NULL; 6111 6112 btrfs_release_path(path); 6113 trans = btrfs_join_transaction(root); 6114 6115 if (IS_ERR(trans)) 6116 return ERR_CAST(trans); 6117 goto again; 6118 } 6119 map = kmap(page); 6120 write_extent_buffer(leaf, map + pg_offset, ptr, 6121 copy_size); 6122 kunmap(page); 6123 btrfs_mark_buffer_dirty(leaf); 6124 } 6125 set_extent_uptodate(io_tree, em->start, 6126 extent_map_end(em) - 1, NULL, GFP_NOFS); 6127 goto insert; 6128 } else { 6129 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type); 6130 } 6131 not_found: 6132 em->start = start; 6133 em->orig_start = start; 6134 em->len = len; 6135 not_found_em: 6136 em->block_start = EXTENT_MAP_HOLE; 6137 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6138 insert: 6139 btrfs_release_path(path); 6140 if (em->start > start || extent_map_end(em) <= start) { 6141 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", 6142 (unsigned long long)em->start, 6143 (unsigned long long)em->len, 6144 (unsigned long long)start, 6145 (unsigned long long)len); 6146 err = -EIO; 6147 goto out; 6148 } 6149 6150 err = 0; 6151 write_lock(&em_tree->lock); 6152 ret = add_extent_mapping(em_tree, em, 0); 6153 /* it is possible that someone inserted the extent into the tree 6154 * while we had the lock dropped. It is also possible that 6155 * an overlapping map exists in the tree 6156 */ 6157 if (ret == -EEXIST) { 6158 struct extent_map *existing; 6159 6160 ret = 0; 6161 6162 existing = lookup_extent_mapping(em_tree, start, len); 6163 if (existing && (existing->start > start || 6164 existing->start + existing->len <= start)) { 6165 free_extent_map(existing); 6166 existing = NULL; 6167 } 6168 if (!existing) { 6169 existing = lookup_extent_mapping(em_tree, em->start, 6170 em->len); 6171 if (existing) { 6172 err = merge_extent_mapping(em_tree, existing, 6173 em, start, 6174 root->sectorsize); 6175 free_extent_map(existing); 6176 if (err) { 6177 free_extent_map(em); 6178 em = NULL; 6179 } 6180 } else { 6181 err = -EIO; 6182 free_extent_map(em); 6183 em = NULL; 6184 } 6185 } else { 6186 free_extent_map(em); 6187 em = existing; 6188 err = 0; 6189 } 6190 } 6191 write_unlock(&em_tree->lock); 6192 out: 6193 6194 if (em) 6195 trace_btrfs_get_extent(root, em); 6196 6197 if (path) 6198 btrfs_free_path(path); 6199 if (trans) { 6200 ret = btrfs_end_transaction(trans, root); 6201 if (!err) 6202 err = ret; 6203 } 6204 if (err) { 6205 free_extent_map(em); 6206 return ERR_PTR(err); 6207 } 6208 BUG_ON(!em); /* Error is always set */ 6209 return em; 6210 } 6211 6212 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, 6213 size_t pg_offset, u64 start, u64 len, 6214 int create) 6215 { 6216 struct extent_map *em; 6217 struct extent_map *hole_em = NULL; 6218 u64 range_start = start; 6219 u64 end; 6220 u64 found; 6221 u64 found_end; 6222 int err = 0; 6223 6224 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 6225 if (IS_ERR(em)) 6226 return em; 6227 if (em) { 6228 /* 6229 * if our em maps to 6230 * - a hole or 6231 * - a pre-alloc extent, 6232 * there might actually be delalloc bytes behind it. 6233 */ 6234 if (em->block_start != EXTENT_MAP_HOLE && 6235 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6236 return em; 6237 else 6238 hole_em = em; 6239 } 6240 6241 /* check to see if we've wrapped (len == -1 or similar) */ 6242 end = start + len; 6243 if (end < start) 6244 end = (u64)-1; 6245 else 6246 end -= 1; 6247 6248 em = NULL; 6249 6250 /* ok, we didn't find anything, lets look for delalloc */ 6251 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, 6252 end, len, EXTENT_DELALLOC, 1); 6253 found_end = range_start + found; 6254 if (found_end < range_start) 6255 found_end = (u64)-1; 6256 6257 /* 6258 * we didn't find anything useful, return 6259 * the original results from get_extent() 6260 */ 6261 if (range_start > end || found_end <= start) { 6262 em = hole_em; 6263 hole_em = NULL; 6264 goto out; 6265 } 6266 6267 /* adjust the range_start to make sure it doesn't 6268 * go backwards from the start they passed in 6269 */ 6270 range_start = max(start,range_start); 6271 found = found_end - range_start; 6272 6273 if (found > 0) { 6274 u64 hole_start = start; 6275 u64 hole_len = len; 6276 6277 em = alloc_extent_map(); 6278 if (!em) { 6279 err = -ENOMEM; 6280 goto out; 6281 } 6282 /* 6283 * when btrfs_get_extent can't find anything it 6284 * returns one huge hole 6285 * 6286 * make sure what it found really fits our range, and 6287 * adjust to make sure it is based on the start from 6288 * the caller 6289 */ 6290 if (hole_em) { 6291 u64 calc_end = extent_map_end(hole_em); 6292 6293 if (calc_end <= start || (hole_em->start > end)) { 6294 free_extent_map(hole_em); 6295 hole_em = NULL; 6296 } else { 6297 hole_start = max(hole_em->start, start); 6298 hole_len = calc_end - hole_start; 6299 } 6300 } 6301 em->bdev = NULL; 6302 if (hole_em && range_start > hole_start) { 6303 /* our hole starts before our delalloc, so we 6304 * have to return just the parts of the hole 6305 * that go until the delalloc starts 6306 */ 6307 em->len = min(hole_len, 6308 range_start - hole_start); 6309 em->start = hole_start; 6310 em->orig_start = hole_start; 6311 /* 6312 * don't adjust block start at all, 6313 * it is fixed at EXTENT_MAP_HOLE 6314 */ 6315 em->block_start = hole_em->block_start; 6316 em->block_len = hole_len; 6317 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 6318 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6319 } else { 6320 em->start = range_start; 6321 em->len = found; 6322 em->orig_start = range_start; 6323 em->block_start = EXTENT_MAP_DELALLOC; 6324 em->block_len = found; 6325 } 6326 } else if (hole_em) { 6327 return hole_em; 6328 } 6329 out: 6330 6331 free_extent_map(hole_em); 6332 if (err) { 6333 free_extent_map(em); 6334 return ERR_PTR(err); 6335 } 6336 return em; 6337 } 6338 6339 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 6340 u64 start, u64 len) 6341 { 6342 struct btrfs_root *root = BTRFS_I(inode)->root; 6343 struct btrfs_trans_handle *trans; 6344 struct extent_map *em; 6345 struct btrfs_key ins; 6346 u64 alloc_hint; 6347 int ret; 6348 6349 trans = btrfs_join_transaction(root); 6350 if (IS_ERR(trans)) 6351 return ERR_CAST(trans); 6352 6353 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 6354 6355 alloc_hint = get_extent_allocation_hint(inode, start, len); 6356 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0, 6357 alloc_hint, &ins, 1); 6358 if (ret) { 6359 em = ERR_PTR(ret); 6360 goto out; 6361 } 6362 6363 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, 6364 ins.offset, ins.offset, ins.offset, 0); 6365 if (IS_ERR(em)) 6366 goto out; 6367 6368 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, 6369 ins.offset, ins.offset, 0); 6370 if (ret) { 6371 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 6372 em = ERR_PTR(ret); 6373 } 6374 out: 6375 btrfs_end_transaction(trans, root); 6376 return em; 6377 } 6378 6379 /* 6380 * returns 1 when the nocow is safe, < 1 on error, 0 if the 6381 * block must be cow'd 6382 */ 6383 noinline int can_nocow_extent(struct btrfs_trans_handle *trans, 6384 struct inode *inode, u64 offset, u64 *len, 6385 u64 *orig_start, u64 *orig_block_len, 6386 u64 *ram_bytes) 6387 { 6388 struct btrfs_path *path; 6389 int ret; 6390 struct extent_buffer *leaf; 6391 struct btrfs_root *root = BTRFS_I(inode)->root; 6392 struct btrfs_file_extent_item *fi; 6393 struct btrfs_key key; 6394 u64 disk_bytenr; 6395 u64 backref_offset; 6396 u64 extent_end; 6397 u64 num_bytes; 6398 int slot; 6399 int found_type; 6400 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); 6401 path = btrfs_alloc_path(); 6402 if (!path) 6403 return -ENOMEM; 6404 6405 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode), 6406 offset, 0); 6407 if (ret < 0) 6408 goto out; 6409 6410 slot = path->slots[0]; 6411 if (ret == 1) { 6412 if (slot == 0) { 6413 /* can't find the item, must cow */ 6414 ret = 0; 6415 goto out; 6416 } 6417 slot--; 6418 } 6419 ret = 0; 6420 leaf = path->nodes[0]; 6421 btrfs_item_key_to_cpu(leaf, &key, slot); 6422 if (key.objectid != btrfs_ino(inode) || 6423 key.type != BTRFS_EXTENT_DATA_KEY) { 6424 /* not our file or wrong item type, must cow */ 6425 goto out; 6426 } 6427 6428 if (key.offset > offset) { 6429 /* Wrong offset, must cow */ 6430 goto out; 6431 } 6432 6433 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 6434 found_type = btrfs_file_extent_type(leaf, fi); 6435 if (found_type != BTRFS_FILE_EXTENT_REG && 6436 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 6437 /* not a regular extent, must cow */ 6438 goto out; 6439 } 6440 6441 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) 6442 goto out; 6443 6444 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 6445 if (disk_bytenr == 0) 6446 goto out; 6447 6448 if (btrfs_file_extent_compression(leaf, fi) || 6449 btrfs_file_extent_encryption(leaf, fi) || 6450 btrfs_file_extent_other_encoding(leaf, fi)) 6451 goto out; 6452 6453 backref_offset = btrfs_file_extent_offset(leaf, fi); 6454 6455 if (orig_start) { 6456 *orig_start = key.offset - backref_offset; 6457 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 6458 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 6459 } 6460 6461 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 6462 6463 if (btrfs_extent_readonly(root, disk_bytenr)) 6464 goto out; 6465 6466 /* 6467 * look for other files referencing this extent, if we 6468 * find any we must cow 6469 */ 6470 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), 6471 key.offset - backref_offset, disk_bytenr)) 6472 goto out; 6473 6474 /* 6475 * adjust disk_bytenr and num_bytes to cover just the bytes 6476 * in this extent we are about to write. If there 6477 * are any csums in that range we have to cow in order 6478 * to keep the csums correct 6479 */ 6480 disk_bytenr += backref_offset; 6481 disk_bytenr += offset - key.offset; 6482 num_bytes = min(offset + *len, extent_end) - offset; 6483 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 6484 goto out; 6485 /* 6486 * all of the above have passed, it is safe to overwrite this extent 6487 * without cow 6488 */ 6489 *len = num_bytes; 6490 ret = 1; 6491 out: 6492 btrfs_free_path(path); 6493 return ret; 6494 } 6495 6496 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 6497 struct extent_state **cached_state, int writing) 6498 { 6499 struct btrfs_ordered_extent *ordered; 6500 int ret = 0; 6501 6502 while (1) { 6503 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6504 0, cached_state); 6505 /* 6506 * We're concerned with the entire range that we're going to be 6507 * doing DIO to, so we need to make sure theres no ordered 6508 * extents in this range. 6509 */ 6510 ordered = btrfs_lookup_ordered_range(inode, lockstart, 6511 lockend - lockstart + 1); 6512 6513 /* 6514 * We need to make sure there are no buffered pages in this 6515 * range either, we could have raced between the invalidate in 6516 * generic_file_direct_write and locking the extent. The 6517 * invalidate needs to happen so that reads after a write do not 6518 * get stale data. 6519 */ 6520 if (!ordered && (!writing || 6521 !test_range_bit(&BTRFS_I(inode)->io_tree, 6522 lockstart, lockend, EXTENT_UPTODATE, 0, 6523 *cached_state))) 6524 break; 6525 6526 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6527 cached_state, GFP_NOFS); 6528 6529 if (ordered) { 6530 btrfs_start_ordered_extent(inode, ordered, 1); 6531 btrfs_put_ordered_extent(ordered); 6532 } else { 6533 /* Screw you mmap */ 6534 ret = filemap_write_and_wait_range(inode->i_mapping, 6535 lockstart, 6536 lockend); 6537 if (ret) 6538 break; 6539 6540 /* 6541 * If we found a page that couldn't be invalidated just 6542 * fall back to buffered. 6543 */ 6544 ret = invalidate_inode_pages2_range(inode->i_mapping, 6545 lockstart >> PAGE_CACHE_SHIFT, 6546 lockend >> PAGE_CACHE_SHIFT); 6547 if (ret) 6548 break; 6549 } 6550 6551 cond_resched(); 6552 } 6553 6554 return ret; 6555 } 6556 6557 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 6558 u64 len, u64 orig_start, 6559 u64 block_start, u64 block_len, 6560 u64 orig_block_len, u64 ram_bytes, 6561 int type) 6562 { 6563 struct extent_map_tree *em_tree; 6564 struct extent_map *em; 6565 struct btrfs_root *root = BTRFS_I(inode)->root; 6566 int ret; 6567 6568 em_tree = &BTRFS_I(inode)->extent_tree; 6569 em = alloc_extent_map(); 6570 if (!em) 6571 return ERR_PTR(-ENOMEM); 6572 6573 em->start = start; 6574 em->orig_start = orig_start; 6575 em->mod_start = start; 6576 em->mod_len = len; 6577 em->len = len; 6578 em->block_len = block_len; 6579 em->block_start = block_start; 6580 em->bdev = root->fs_info->fs_devices->latest_bdev; 6581 em->orig_block_len = orig_block_len; 6582 em->ram_bytes = ram_bytes; 6583 em->generation = -1; 6584 set_bit(EXTENT_FLAG_PINNED, &em->flags); 6585 if (type == BTRFS_ORDERED_PREALLOC) 6586 set_bit(EXTENT_FLAG_FILLING, &em->flags); 6587 6588 do { 6589 btrfs_drop_extent_cache(inode, em->start, 6590 em->start + em->len - 1, 0); 6591 write_lock(&em_tree->lock); 6592 ret = add_extent_mapping(em_tree, em, 1); 6593 write_unlock(&em_tree->lock); 6594 } while (ret == -EEXIST); 6595 6596 if (ret) { 6597 free_extent_map(em); 6598 return ERR_PTR(ret); 6599 } 6600 6601 return em; 6602 } 6603 6604 6605 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 6606 struct buffer_head *bh_result, int create) 6607 { 6608 struct extent_map *em; 6609 struct btrfs_root *root = BTRFS_I(inode)->root; 6610 struct extent_state *cached_state = NULL; 6611 u64 start = iblock << inode->i_blkbits; 6612 u64 lockstart, lockend; 6613 u64 len = bh_result->b_size; 6614 struct btrfs_trans_handle *trans; 6615 int unlock_bits = EXTENT_LOCKED; 6616 int ret = 0; 6617 6618 if (create) 6619 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY; 6620 else 6621 len = min_t(u64, len, root->sectorsize); 6622 6623 lockstart = start; 6624 lockend = start + len - 1; 6625 6626 /* 6627 * If this errors out it's because we couldn't invalidate pagecache for 6628 * this range and we need to fallback to buffered. 6629 */ 6630 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) 6631 return -ENOTBLK; 6632 6633 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 6634 if (IS_ERR(em)) { 6635 ret = PTR_ERR(em); 6636 goto unlock_err; 6637 } 6638 6639 /* 6640 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 6641 * io. INLINE is special, and we could probably kludge it in here, but 6642 * it's still buffered so for safety lets just fall back to the generic 6643 * buffered path. 6644 * 6645 * For COMPRESSED we _have_ to read the entire extent in so we can 6646 * decompress it, so there will be buffering required no matter what we 6647 * do, so go ahead and fallback to buffered. 6648 * 6649 * We return -ENOTBLK because thats what makes DIO go ahead and go back 6650 * to buffered IO. Don't blame me, this is the price we pay for using 6651 * the generic code. 6652 */ 6653 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 6654 em->block_start == EXTENT_MAP_INLINE) { 6655 free_extent_map(em); 6656 ret = -ENOTBLK; 6657 goto unlock_err; 6658 } 6659 6660 /* Just a good old fashioned hole, return */ 6661 if (!create && (em->block_start == EXTENT_MAP_HOLE || 6662 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 6663 free_extent_map(em); 6664 goto unlock_err; 6665 } 6666 6667 /* 6668 * We don't allocate a new extent in the following cases 6669 * 6670 * 1) The inode is marked as NODATACOW. In this case we'll just use the 6671 * existing extent. 6672 * 2) The extent is marked as PREALLOC. We're good to go here and can 6673 * just use the extent. 6674 * 6675 */ 6676 if (!create) { 6677 len = min(len, em->len - (start - em->start)); 6678 lockstart = start + len; 6679 goto unlock; 6680 } 6681 6682 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 6683 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 6684 em->block_start != EXTENT_MAP_HOLE)) { 6685 int type; 6686 int ret; 6687 u64 block_start, orig_start, orig_block_len, ram_bytes; 6688 6689 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6690 type = BTRFS_ORDERED_PREALLOC; 6691 else 6692 type = BTRFS_ORDERED_NOCOW; 6693 len = min(len, em->len - (start - em->start)); 6694 block_start = em->block_start + (start - em->start); 6695 6696 /* 6697 * we're not going to log anything, but we do need 6698 * to make sure the current transaction stays open 6699 * while we look for nocow cross refs 6700 */ 6701 trans = btrfs_join_transaction(root); 6702 if (IS_ERR(trans)) 6703 goto must_cow; 6704 6705 if (can_nocow_extent(trans, inode, start, &len, &orig_start, 6706 &orig_block_len, &ram_bytes) == 1) { 6707 if (type == BTRFS_ORDERED_PREALLOC) { 6708 free_extent_map(em); 6709 em = create_pinned_em(inode, start, len, 6710 orig_start, 6711 block_start, len, 6712 orig_block_len, 6713 ram_bytes, type); 6714 if (IS_ERR(em)) { 6715 btrfs_end_transaction(trans, root); 6716 goto unlock_err; 6717 } 6718 } 6719 6720 ret = btrfs_add_ordered_extent_dio(inode, start, 6721 block_start, len, len, type); 6722 btrfs_end_transaction(trans, root); 6723 if (ret) { 6724 free_extent_map(em); 6725 goto unlock_err; 6726 } 6727 goto unlock; 6728 } 6729 btrfs_end_transaction(trans, root); 6730 } 6731 must_cow: 6732 /* 6733 * this will cow the extent, reset the len in case we changed 6734 * it above 6735 */ 6736 len = bh_result->b_size; 6737 free_extent_map(em); 6738 em = btrfs_new_extent_direct(inode, start, len); 6739 if (IS_ERR(em)) { 6740 ret = PTR_ERR(em); 6741 goto unlock_err; 6742 } 6743 len = min(len, em->len - (start - em->start)); 6744 unlock: 6745 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 6746 inode->i_blkbits; 6747 bh_result->b_size = len; 6748 bh_result->b_bdev = em->bdev; 6749 set_buffer_mapped(bh_result); 6750 if (create) { 6751 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6752 set_buffer_new(bh_result); 6753 6754 /* 6755 * Need to update the i_size under the extent lock so buffered 6756 * readers will get the updated i_size when we unlock. 6757 */ 6758 if (start + len > i_size_read(inode)) 6759 i_size_write(inode, start + len); 6760 6761 spin_lock(&BTRFS_I(inode)->lock); 6762 BTRFS_I(inode)->outstanding_extents++; 6763 spin_unlock(&BTRFS_I(inode)->lock); 6764 6765 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6766 lockstart + len - 1, EXTENT_DELALLOC, NULL, 6767 &cached_state, GFP_NOFS); 6768 BUG_ON(ret); 6769 } 6770 6771 /* 6772 * In the case of write we need to clear and unlock the entire range, 6773 * in the case of read we need to unlock only the end area that we 6774 * aren't using if there is any left over space. 6775 */ 6776 if (lockstart < lockend) { 6777 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6778 lockend, unlock_bits, 1, 0, 6779 &cached_state, GFP_NOFS); 6780 } else { 6781 free_extent_state(cached_state); 6782 } 6783 6784 free_extent_map(em); 6785 6786 return 0; 6787 6788 unlock_err: 6789 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6790 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 6791 return ret; 6792 } 6793 6794 struct btrfs_dio_private { 6795 struct inode *inode; 6796 u64 logical_offset; 6797 u64 disk_bytenr; 6798 u64 bytes; 6799 void *private; 6800 6801 /* number of bios pending for this dio */ 6802 atomic_t pending_bios; 6803 6804 /* IO errors */ 6805 int errors; 6806 6807 /* orig_bio is our btrfs_io_bio */ 6808 struct bio *orig_bio; 6809 6810 /* dio_bio came from fs/direct-io.c */ 6811 struct bio *dio_bio; 6812 }; 6813 6814 static void btrfs_endio_direct_read(struct bio *bio, int err) 6815 { 6816 struct btrfs_dio_private *dip = bio->bi_private; 6817 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1; 6818 struct bio_vec *bvec = bio->bi_io_vec; 6819 struct inode *inode = dip->inode; 6820 struct btrfs_root *root = BTRFS_I(inode)->root; 6821 struct bio *dio_bio; 6822 u64 start; 6823 6824 start = dip->logical_offset; 6825 do { 6826 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { 6827 struct page *page = bvec->bv_page; 6828 char *kaddr; 6829 u32 csum = ~(u32)0; 6830 u64 private = ~(u32)0; 6831 unsigned long flags; 6832 6833 if (get_state_private(&BTRFS_I(inode)->io_tree, 6834 start, &private)) 6835 goto failed; 6836 local_irq_save(flags); 6837 kaddr = kmap_atomic(page); 6838 csum = btrfs_csum_data(kaddr + bvec->bv_offset, 6839 csum, bvec->bv_len); 6840 btrfs_csum_final(csum, (char *)&csum); 6841 kunmap_atomic(kaddr); 6842 local_irq_restore(flags); 6843 6844 flush_dcache_page(bvec->bv_page); 6845 if (csum != private) { 6846 failed: 6847 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u", 6848 (unsigned long long)btrfs_ino(inode), 6849 (unsigned long long)start, 6850 csum, (unsigned)private); 6851 err = -EIO; 6852 } 6853 } 6854 6855 start += bvec->bv_len; 6856 bvec++; 6857 } while (bvec <= bvec_end); 6858 6859 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 6860 dip->logical_offset + dip->bytes - 1); 6861 dio_bio = dip->dio_bio; 6862 6863 kfree(dip); 6864 6865 /* If we had a csum failure make sure to clear the uptodate flag */ 6866 if (err) 6867 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 6868 dio_end_io(dio_bio, err); 6869 bio_put(bio); 6870 } 6871 6872 static void btrfs_endio_direct_write(struct bio *bio, int err) 6873 { 6874 struct btrfs_dio_private *dip = bio->bi_private; 6875 struct inode *inode = dip->inode; 6876 struct btrfs_root *root = BTRFS_I(inode)->root; 6877 struct btrfs_ordered_extent *ordered = NULL; 6878 u64 ordered_offset = dip->logical_offset; 6879 u64 ordered_bytes = dip->bytes; 6880 struct bio *dio_bio; 6881 int ret; 6882 6883 if (err) 6884 goto out_done; 6885 again: 6886 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 6887 &ordered_offset, 6888 ordered_bytes, !err); 6889 if (!ret) 6890 goto out_test; 6891 6892 ordered->work.func = finish_ordered_fn; 6893 ordered->work.flags = 0; 6894 btrfs_queue_worker(&root->fs_info->endio_write_workers, 6895 &ordered->work); 6896 out_test: 6897 /* 6898 * our bio might span multiple ordered extents. If we haven't 6899 * completed the accounting for the whole dio, go back and try again 6900 */ 6901 if (ordered_offset < dip->logical_offset + dip->bytes) { 6902 ordered_bytes = dip->logical_offset + dip->bytes - 6903 ordered_offset; 6904 ordered = NULL; 6905 goto again; 6906 } 6907 out_done: 6908 dio_bio = dip->dio_bio; 6909 6910 kfree(dip); 6911 6912 /* If we had an error make sure to clear the uptodate flag */ 6913 if (err) 6914 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 6915 dio_end_io(dio_bio, err); 6916 bio_put(bio); 6917 } 6918 6919 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, 6920 struct bio *bio, int mirror_num, 6921 unsigned long bio_flags, u64 offset) 6922 { 6923 int ret; 6924 struct btrfs_root *root = BTRFS_I(inode)->root; 6925 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); 6926 BUG_ON(ret); /* -ENOMEM */ 6927 return 0; 6928 } 6929 6930 static void btrfs_end_dio_bio(struct bio *bio, int err) 6931 { 6932 struct btrfs_dio_private *dip = bio->bi_private; 6933 6934 if (err) { 6935 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu " 6936 "sector %#Lx len %u err no %d\n", 6937 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw, 6938 (unsigned long long)bio->bi_sector, bio->bi_size, err); 6939 dip->errors = 1; 6940 6941 /* 6942 * before atomic variable goto zero, we must make sure 6943 * dip->errors is perceived to be set. 6944 */ 6945 smp_mb__before_atomic_dec(); 6946 } 6947 6948 /* if there are more bios still pending for this dio, just exit */ 6949 if (!atomic_dec_and_test(&dip->pending_bios)) 6950 goto out; 6951 6952 if (dip->errors) { 6953 bio_io_error(dip->orig_bio); 6954 } else { 6955 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags); 6956 bio_endio(dip->orig_bio, 0); 6957 } 6958 out: 6959 bio_put(bio); 6960 } 6961 6962 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 6963 u64 first_sector, gfp_t gfp_flags) 6964 { 6965 int nr_vecs = bio_get_nr_vecs(bdev); 6966 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); 6967 } 6968 6969 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 6970 int rw, u64 file_offset, int skip_sum, 6971 int async_submit) 6972 { 6973 int write = rw & REQ_WRITE; 6974 struct btrfs_root *root = BTRFS_I(inode)->root; 6975 int ret; 6976 6977 if (async_submit) 6978 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 6979 6980 bio_get(bio); 6981 6982 if (!write) { 6983 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); 6984 if (ret) 6985 goto err; 6986 } 6987 6988 if (skip_sum) 6989 goto map; 6990 6991 if (write && async_submit) { 6992 ret = btrfs_wq_submit_bio(root->fs_info, 6993 inode, rw, bio, 0, 0, 6994 file_offset, 6995 __btrfs_submit_bio_start_direct_io, 6996 __btrfs_submit_bio_done); 6997 goto err; 6998 } else if (write) { 6999 /* 7000 * If we aren't doing async submit, calculate the csum of the 7001 * bio now. 7002 */ 7003 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); 7004 if (ret) 7005 goto err; 7006 } else if (!skip_sum) { 7007 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset); 7008 if (ret) 7009 goto err; 7010 } 7011 7012 map: 7013 ret = btrfs_map_bio(root, rw, bio, 0, async_submit); 7014 err: 7015 bio_put(bio); 7016 return ret; 7017 } 7018 7019 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, 7020 int skip_sum) 7021 { 7022 struct inode *inode = dip->inode; 7023 struct btrfs_root *root = BTRFS_I(inode)->root; 7024 struct bio *bio; 7025 struct bio *orig_bio = dip->orig_bio; 7026 struct bio_vec *bvec = orig_bio->bi_io_vec; 7027 u64 start_sector = orig_bio->bi_sector; 7028 u64 file_offset = dip->logical_offset; 7029 u64 submit_len = 0; 7030 u64 map_length; 7031 int nr_pages = 0; 7032 int ret = 0; 7033 int async_submit = 0; 7034 7035 map_length = orig_bio->bi_size; 7036 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, 7037 &map_length, NULL, 0); 7038 if (ret) { 7039 bio_put(orig_bio); 7040 return -EIO; 7041 } 7042 if (map_length >= orig_bio->bi_size) { 7043 bio = orig_bio; 7044 goto submit; 7045 } 7046 7047 /* async crcs make it difficult to collect full stripe writes. */ 7048 if (btrfs_get_alloc_profile(root, 1) & 7049 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) 7050 async_submit = 0; 7051 else 7052 async_submit = 1; 7053 7054 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 7055 if (!bio) 7056 return -ENOMEM; 7057 bio->bi_private = dip; 7058 bio->bi_end_io = btrfs_end_dio_bio; 7059 atomic_inc(&dip->pending_bios); 7060 7061 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { 7062 if (unlikely(map_length < submit_len + bvec->bv_len || 7063 bio_add_page(bio, bvec->bv_page, bvec->bv_len, 7064 bvec->bv_offset) < bvec->bv_len)) { 7065 /* 7066 * inc the count before we submit the bio so 7067 * we know the end IO handler won't happen before 7068 * we inc the count. Otherwise, the dip might get freed 7069 * before we're done setting it up 7070 */ 7071 atomic_inc(&dip->pending_bios); 7072 ret = __btrfs_submit_dio_bio(bio, inode, rw, 7073 file_offset, skip_sum, 7074 async_submit); 7075 if (ret) { 7076 bio_put(bio); 7077 atomic_dec(&dip->pending_bios); 7078 goto out_err; 7079 } 7080 7081 start_sector += submit_len >> 9; 7082 file_offset += submit_len; 7083 7084 submit_len = 0; 7085 nr_pages = 0; 7086 7087 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 7088 start_sector, GFP_NOFS); 7089 if (!bio) 7090 goto out_err; 7091 bio->bi_private = dip; 7092 bio->bi_end_io = btrfs_end_dio_bio; 7093 7094 map_length = orig_bio->bi_size; 7095 ret = btrfs_map_block(root->fs_info, rw, 7096 start_sector << 9, 7097 &map_length, NULL, 0); 7098 if (ret) { 7099 bio_put(bio); 7100 goto out_err; 7101 } 7102 } else { 7103 submit_len += bvec->bv_len; 7104 nr_pages ++; 7105 bvec++; 7106 } 7107 } 7108 7109 submit: 7110 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, 7111 async_submit); 7112 if (!ret) 7113 return 0; 7114 7115 bio_put(bio); 7116 out_err: 7117 dip->errors = 1; 7118 /* 7119 * before atomic variable goto zero, we must 7120 * make sure dip->errors is perceived to be set. 7121 */ 7122 smp_mb__before_atomic_dec(); 7123 if (atomic_dec_and_test(&dip->pending_bios)) 7124 bio_io_error(dip->orig_bio); 7125 7126 /* bio_end_io() will handle error, so we needn't return it */ 7127 return 0; 7128 } 7129 7130 static void btrfs_submit_direct(int rw, struct bio *dio_bio, 7131 struct inode *inode, loff_t file_offset) 7132 { 7133 struct btrfs_root *root = BTRFS_I(inode)->root; 7134 struct btrfs_dio_private *dip; 7135 struct bio *io_bio; 7136 int skip_sum; 7137 int write = rw & REQ_WRITE; 7138 int ret = 0; 7139 7140 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 7141 7142 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); 7143 7144 if (!io_bio) { 7145 ret = -ENOMEM; 7146 goto free_ordered; 7147 } 7148 7149 dip = kmalloc(sizeof(*dip), GFP_NOFS); 7150 if (!dip) { 7151 ret = -ENOMEM; 7152 goto free_io_bio; 7153 } 7154 7155 dip->private = dio_bio->bi_private; 7156 dip->inode = inode; 7157 dip->logical_offset = file_offset; 7158 dip->bytes = dio_bio->bi_size; 7159 dip->disk_bytenr = (u64)dio_bio->bi_sector << 9; 7160 io_bio->bi_private = dip; 7161 dip->errors = 0; 7162 dip->orig_bio = io_bio; 7163 dip->dio_bio = dio_bio; 7164 atomic_set(&dip->pending_bios, 0); 7165 7166 if (write) 7167 io_bio->bi_end_io = btrfs_endio_direct_write; 7168 else 7169 io_bio->bi_end_io = btrfs_endio_direct_read; 7170 7171 ret = btrfs_submit_direct_hook(rw, dip, skip_sum); 7172 if (!ret) 7173 return; 7174 7175 free_io_bio: 7176 bio_put(io_bio); 7177 7178 free_ordered: 7179 /* 7180 * If this is a write, we need to clean up the reserved space and kill 7181 * the ordered extent. 7182 */ 7183 if (write) { 7184 struct btrfs_ordered_extent *ordered; 7185 ordered = btrfs_lookup_ordered_extent(inode, file_offset); 7186 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && 7187 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) 7188 btrfs_free_reserved_extent(root, ordered->start, 7189 ordered->disk_len); 7190 btrfs_put_ordered_extent(ordered); 7191 btrfs_put_ordered_extent(ordered); 7192 } 7193 bio_endio(dio_bio, ret); 7194 } 7195 7196 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb, 7197 const struct iovec *iov, loff_t offset, 7198 unsigned long nr_segs) 7199 { 7200 int seg; 7201 int i; 7202 size_t size; 7203 unsigned long addr; 7204 unsigned blocksize_mask = root->sectorsize - 1; 7205 ssize_t retval = -EINVAL; 7206 loff_t end = offset; 7207 7208 if (offset & blocksize_mask) 7209 goto out; 7210 7211 /* Check the memory alignment. Blocks cannot straddle pages */ 7212 for (seg = 0; seg < nr_segs; seg++) { 7213 addr = (unsigned long)iov[seg].iov_base; 7214 size = iov[seg].iov_len; 7215 end += size; 7216 if ((addr & blocksize_mask) || (size & blocksize_mask)) 7217 goto out; 7218 7219 /* If this is a write we don't need to check anymore */ 7220 if (rw & WRITE) 7221 continue; 7222 7223 /* 7224 * Check to make sure we don't have duplicate iov_base's in this 7225 * iovec, if so return EINVAL, otherwise we'll get csum errors 7226 * when reading back. 7227 */ 7228 for (i = seg + 1; i < nr_segs; i++) { 7229 if (iov[seg].iov_base == iov[i].iov_base) 7230 goto out; 7231 } 7232 } 7233 retval = 0; 7234 out: 7235 return retval; 7236 } 7237 7238 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, 7239 const struct iovec *iov, loff_t offset, 7240 unsigned long nr_segs) 7241 { 7242 struct file *file = iocb->ki_filp; 7243 struct inode *inode = file->f_mapping->host; 7244 size_t count = 0; 7245 int flags = 0; 7246 bool wakeup = true; 7247 bool relock = false; 7248 ssize_t ret; 7249 7250 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov, 7251 offset, nr_segs)) 7252 return 0; 7253 7254 atomic_inc(&inode->i_dio_count); 7255 smp_mb__after_atomic_inc(); 7256 7257 /* 7258 * The generic stuff only does filemap_write_and_wait_range, which isn't 7259 * enough if we've written compressed pages to this area, so we need to 7260 * call btrfs_wait_ordered_range to make absolutely sure that any 7261 * outstanding dirty pages are on disk. 7262 */ 7263 count = iov_length(iov, nr_segs); 7264 btrfs_wait_ordered_range(inode, offset, count); 7265 7266 if (rw & WRITE) { 7267 /* 7268 * If the write DIO is beyond the EOF, we need update 7269 * the isize, but it is protected by i_mutex. So we can 7270 * not unlock the i_mutex at this case. 7271 */ 7272 if (offset + count <= inode->i_size) { 7273 mutex_unlock(&inode->i_mutex); 7274 relock = true; 7275 } 7276 ret = btrfs_delalloc_reserve_space(inode, count); 7277 if (ret) 7278 goto out; 7279 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 7280 &BTRFS_I(inode)->runtime_flags))) { 7281 inode_dio_done(inode); 7282 flags = DIO_LOCKING | DIO_SKIP_HOLES; 7283 wakeup = false; 7284 } 7285 7286 ret = __blockdev_direct_IO(rw, iocb, inode, 7287 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, 7288 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL, 7289 btrfs_submit_direct, flags); 7290 if (rw & WRITE) { 7291 if (ret < 0 && ret != -EIOCBQUEUED) 7292 btrfs_delalloc_release_space(inode, count); 7293 else if (ret >= 0 && (size_t)ret < count) 7294 btrfs_delalloc_release_space(inode, 7295 count - (size_t)ret); 7296 else 7297 btrfs_delalloc_release_metadata(inode, 0); 7298 } 7299 out: 7300 if (wakeup) 7301 inode_dio_done(inode); 7302 if (relock) 7303 mutex_lock(&inode->i_mutex); 7304 7305 return ret; 7306 } 7307 7308 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 7309 7310 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 7311 __u64 start, __u64 len) 7312 { 7313 int ret; 7314 7315 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 7316 if (ret) 7317 return ret; 7318 7319 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 7320 } 7321 7322 int btrfs_readpage(struct file *file, struct page *page) 7323 { 7324 struct extent_io_tree *tree; 7325 tree = &BTRFS_I(page->mapping->host)->io_tree; 7326 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 7327 } 7328 7329 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 7330 { 7331 struct extent_io_tree *tree; 7332 7333 7334 if (current->flags & PF_MEMALLOC) { 7335 redirty_page_for_writepage(wbc, page); 7336 unlock_page(page); 7337 return 0; 7338 } 7339 tree = &BTRFS_I(page->mapping->host)->io_tree; 7340 return extent_write_full_page(tree, page, btrfs_get_extent, wbc); 7341 } 7342 7343 static int btrfs_writepages(struct address_space *mapping, 7344 struct writeback_control *wbc) 7345 { 7346 struct extent_io_tree *tree; 7347 7348 tree = &BTRFS_I(mapping->host)->io_tree; 7349 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 7350 } 7351 7352 static int 7353 btrfs_readpages(struct file *file, struct address_space *mapping, 7354 struct list_head *pages, unsigned nr_pages) 7355 { 7356 struct extent_io_tree *tree; 7357 tree = &BTRFS_I(mapping->host)->io_tree; 7358 return extent_readpages(tree, mapping, pages, nr_pages, 7359 btrfs_get_extent); 7360 } 7361 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7362 { 7363 struct extent_io_tree *tree; 7364 struct extent_map_tree *map; 7365 int ret; 7366 7367 tree = &BTRFS_I(page->mapping->host)->io_tree; 7368 map = &BTRFS_I(page->mapping->host)->extent_tree; 7369 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 7370 if (ret == 1) { 7371 ClearPagePrivate(page); 7372 set_page_private(page, 0); 7373 page_cache_release(page); 7374 } 7375 return ret; 7376 } 7377 7378 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7379 { 7380 if (PageWriteback(page) || PageDirty(page)) 7381 return 0; 7382 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); 7383 } 7384 7385 static void btrfs_invalidatepage(struct page *page, unsigned int offset, 7386 unsigned int length) 7387 { 7388 struct inode *inode = page->mapping->host; 7389 struct extent_io_tree *tree; 7390 struct btrfs_ordered_extent *ordered; 7391 struct extent_state *cached_state = NULL; 7392 u64 page_start = page_offset(page); 7393 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 7394 7395 /* 7396 * we have the page locked, so new writeback can't start, 7397 * and the dirty bit won't be cleared while we are here. 7398 * 7399 * Wait for IO on this page so that we can safely clear 7400 * the PagePrivate2 bit and do ordered accounting 7401 */ 7402 wait_on_page_writeback(page); 7403 7404 tree = &BTRFS_I(inode)->io_tree; 7405 if (offset) { 7406 btrfs_releasepage(page, GFP_NOFS); 7407 return; 7408 } 7409 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 7410 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page)); 7411 if (ordered) { 7412 /* 7413 * IO on this page will never be started, so we need 7414 * to account for any ordered extents now 7415 */ 7416 clear_extent_bit(tree, page_start, page_end, 7417 EXTENT_DIRTY | EXTENT_DELALLOC | 7418 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 7419 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS); 7420 /* 7421 * whoever cleared the private bit is responsible 7422 * for the finish_ordered_io 7423 */ 7424 if (TestClearPagePrivate2(page) && 7425 btrfs_dec_test_ordered_pending(inode, &ordered, page_start, 7426 PAGE_CACHE_SIZE, 1)) { 7427 btrfs_finish_ordered_io(ordered); 7428 } 7429 btrfs_put_ordered_extent(ordered); 7430 cached_state = NULL; 7431 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 7432 } 7433 clear_extent_bit(tree, page_start, page_end, 7434 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | 7435 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1, 7436 &cached_state, GFP_NOFS); 7437 __btrfs_releasepage(page, GFP_NOFS); 7438 7439 ClearPageChecked(page); 7440 if (PagePrivate(page)) { 7441 ClearPagePrivate(page); 7442 set_page_private(page, 0); 7443 page_cache_release(page); 7444 } 7445 } 7446 7447 /* 7448 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 7449 * called from a page fault handler when a page is first dirtied. Hence we must 7450 * be careful to check for EOF conditions here. We set the page up correctly 7451 * for a written page which means we get ENOSPC checking when writing into 7452 * holes and correct delalloc and unwritten extent mapping on filesystems that 7453 * support these features. 7454 * 7455 * We are not allowed to take the i_mutex here so we have to play games to 7456 * protect against truncate races as the page could now be beyond EOF. Because 7457 * vmtruncate() writes the inode size before removing pages, once we have the 7458 * page lock we can determine safely if the page is beyond EOF. If it is not 7459 * beyond EOF, then the page is guaranteed safe against truncation until we 7460 * unlock the page. 7461 */ 7462 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 7463 { 7464 struct page *page = vmf->page; 7465 struct inode *inode = file_inode(vma->vm_file); 7466 struct btrfs_root *root = BTRFS_I(inode)->root; 7467 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7468 struct btrfs_ordered_extent *ordered; 7469 struct extent_state *cached_state = NULL; 7470 char *kaddr; 7471 unsigned long zero_start; 7472 loff_t size; 7473 int ret; 7474 int reserved = 0; 7475 u64 page_start; 7476 u64 page_end; 7477 7478 sb_start_pagefault(inode->i_sb); 7479 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 7480 if (!ret) { 7481 ret = file_update_time(vma->vm_file); 7482 reserved = 1; 7483 } 7484 if (ret) { 7485 if (ret == -ENOMEM) 7486 ret = VM_FAULT_OOM; 7487 else /* -ENOSPC, -EIO, etc */ 7488 ret = VM_FAULT_SIGBUS; 7489 if (reserved) 7490 goto out; 7491 goto out_noreserve; 7492 } 7493 7494 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 7495 again: 7496 lock_page(page); 7497 size = i_size_read(inode); 7498 page_start = page_offset(page); 7499 page_end = page_start + PAGE_CACHE_SIZE - 1; 7500 7501 if ((page->mapping != inode->i_mapping) || 7502 (page_start >= size)) { 7503 /* page got truncated out from underneath us */ 7504 goto out_unlock; 7505 } 7506 wait_on_page_writeback(page); 7507 7508 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 7509 set_page_extent_mapped(page); 7510 7511 /* 7512 * we can't set the delalloc bits if there are pending ordered 7513 * extents. Drop our locks and wait for them to finish 7514 */ 7515 ordered = btrfs_lookup_ordered_extent(inode, page_start); 7516 if (ordered) { 7517 unlock_extent_cached(io_tree, page_start, page_end, 7518 &cached_state, GFP_NOFS); 7519 unlock_page(page); 7520 btrfs_start_ordered_extent(inode, ordered, 1); 7521 btrfs_put_ordered_extent(ordered); 7522 goto again; 7523 } 7524 7525 /* 7526 * XXX - page_mkwrite gets called every time the page is dirtied, even 7527 * if it was already dirty, so for space accounting reasons we need to 7528 * clear any delalloc bits for the range we are fixing to save. There 7529 * is probably a better way to do this, but for now keep consistent with 7530 * prepare_pages in the normal write path. 7531 */ 7532 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 7533 EXTENT_DIRTY | EXTENT_DELALLOC | 7534 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 7535 0, 0, &cached_state, GFP_NOFS); 7536 7537 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 7538 &cached_state); 7539 if (ret) { 7540 unlock_extent_cached(io_tree, page_start, page_end, 7541 &cached_state, GFP_NOFS); 7542 ret = VM_FAULT_SIGBUS; 7543 goto out_unlock; 7544 } 7545 ret = 0; 7546 7547 /* page is wholly or partially inside EOF */ 7548 if (page_start + PAGE_CACHE_SIZE > size) 7549 zero_start = size & ~PAGE_CACHE_MASK; 7550 else 7551 zero_start = PAGE_CACHE_SIZE; 7552 7553 if (zero_start != PAGE_CACHE_SIZE) { 7554 kaddr = kmap(page); 7555 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); 7556 flush_dcache_page(page); 7557 kunmap(page); 7558 } 7559 ClearPageChecked(page); 7560 set_page_dirty(page); 7561 SetPageUptodate(page); 7562 7563 BTRFS_I(inode)->last_trans = root->fs_info->generation; 7564 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 7565 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 7566 7567 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 7568 7569 out_unlock: 7570 if (!ret) { 7571 sb_end_pagefault(inode->i_sb); 7572 return VM_FAULT_LOCKED; 7573 } 7574 unlock_page(page); 7575 out: 7576 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 7577 out_noreserve: 7578 sb_end_pagefault(inode->i_sb); 7579 return ret; 7580 } 7581 7582 static int btrfs_truncate(struct inode *inode) 7583 { 7584 struct btrfs_root *root = BTRFS_I(inode)->root; 7585 struct btrfs_block_rsv *rsv; 7586 int ret = 0; 7587 int err = 0; 7588 struct btrfs_trans_handle *trans; 7589 u64 mask = root->sectorsize - 1; 7590 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 7591 7592 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1); 7593 btrfs_ordered_update_i_size(inode, inode->i_size, NULL); 7594 7595 /* 7596 * Yes ladies and gentelment, this is indeed ugly. The fact is we have 7597 * 3 things going on here 7598 * 7599 * 1) We need to reserve space for our orphan item and the space to 7600 * delete our orphan item. Lord knows we don't want to have a dangling 7601 * orphan item because we didn't reserve space to remove it. 7602 * 7603 * 2) We need to reserve space to update our inode. 7604 * 7605 * 3) We need to have something to cache all the space that is going to 7606 * be free'd up by the truncate operation, but also have some slack 7607 * space reserved in case it uses space during the truncate (thank you 7608 * very much snapshotting). 7609 * 7610 * And we need these to all be seperate. The fact is we can use alot of 7611 * space doing the truncate, and we have no earthly idea how much space 7612 * we will use, so we need the truncate reservation to be seperate so it 7613 * doesn't end up using space reserved for updating the inode or 7614 * removing the orphan item. We also need to be able to stop the 7615 * transaction and start a new one, which means we need to be able to 7616 * update the inode several times, and we have no idea of knowing how 7617 * many times that will be, so we can't just reserve 1 item for the 7618 * entirety of the opration, so that has to be done seperately as well. 7619 * Then there is the orphan item, which does indeed need to be held on 7620 * to for the whole operation, and we need nobody to touch this reserved 7621 * space except the orphan code. 7622 * 7623 * So that leaves us with 7624 * 7625 * 1) root->orphan_block_rsv - for the orphan deletion. 7626 * 2) rsv - for the truncate reservation, which we will steal from the 7627 * transaction reservation. 7628 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 7629 * updating the inode. 7630 */ 7631 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 7632 if (!rsv) 7633 return -ENOMEM; 7634 rsv->size = min_size; 7635 rsv->failfast = 1; 7636 7637 /* 7638 * 1 for the truncate slack space 7639 * 1 for updating the inode. 7640 */ 7641 trans = btrfs_start_transaction(root, 2); 7642 if (IS_ERR(trans)) { 7643 err = PTR_ERR(trans); 7644 goto out; 7645 } 7646 7647 /* Migrate the slack space for the truncate to our reserve */ 7648 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, 7649 min_size); 7650 BUG_ON(ret); 7651 7652 /* 7653 * setattr is responsible for setting the ordered_data_close flag, 7654 * but that is only tested during the last file release. That 7655 * could happen well after the next commit, leaving a great big 7656 * window where new writes may get lost if someone chooses to write 7657 * to this file after truncating to zero 7658 * 7659 * The inode doesn't have any dirty data here, and so if we commit 7660 * this is a noop. If someone immediately starts writing to the inode 7661 * it is very likely we'll catch some of their writes in this 7662 * transaction, and the commit will find this file on the ordered 7663 * data list with good things to send down. 7664 * 7665 * This is a best effort solution, there is still a window where 7666 * using truncate to replace the contents of the file will 7667 * end up with a zero length file after a crash. 7668 */ 7669 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 7670 &BTRFS_I(inode)->runtime_flags)) 7671 btrfs_add_ordered_operation(trans, root, inode); 7672 7673 /* 7674 * So if we truncate and then write and fsync we normally would just 7675 * write the extents that changed, which is a problem if we need to 7676 * first truncate that entire inode. So set this flag so we write out 7677 * all of the extents in the inode to the sync log so we're completely 7678 * safe. 7679 */ 7680 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 7681 trans->block_rsv = rsv; 7682 7683 while (1) { 7684 ret = btrfs_truncate_inode_items(trans, root, inode, 7685 inode->i_size, 7686 BTRFS_EXTENT_DATA_KEY); 7687 if (ret != -ENOSPC) { 7688 err = ret; 7689 break; 7690 } 7691 7692 trans->block_rsv = &root->fs_info->trans_block_rsv; 7693 ret = btrfs_update_inode(trans, root, inode); 7694 if (ret) { 7695 err = ret; 7696 break; 7697 } 7698 7699 btrfs_end_transaction(trans, root); 7700 btrfs_btree_balance_dirty(root); 7701 7702 trans = btrfs_start_transaction(root, 2); 7703 if (IS_ERR(trans)) { 7704 ret = err = PTR_ERR(trans); 7705 trans = NULL; 7706 break; 7707 } 7708 7709 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, 7710 rsv, min_size); 7711 BUG_ON(ret); /* shouldn't happen */ 7712 trans->block_rsv = rsv; 7713 } 7714 7715 if (ret == 0 && inode->i_nlink > 0) { 7716 trans->block_rsv = root->orphan_block_rsv; 7717 ret = btrfs_orphan_del(trans, inode); 7718 if (ret) 7719 err = ret; 7720 } 7721 7722 if (trans) { 7723 trans->block_rsv = &root->fs_info->trans_block_rsv; 7724 ret = btrfs_update_inode(trans, root, inode); 7725 if (ret && !err) 7726 err = ret; 7727 7728 ret = btrfs_end_transaction(trans, root); 7729 btrfs_btree_balance_dirty(root); 7730 } 7731 7732 out: 7733 btrfs_free_block_rsv(root, rsv); 7734 7735 if (ret && !err) 7736 err = ret; 7737 7738 return err; 7739 } 7740 7741 /* 7742 * create a new subvolume directory/inode (helper for the ioctl). 7743 */ 7744 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 7745 struct btrfs_root *new_root, u64 new_dirid) 7746 { 7747 struct inode *inode; 7748 int err; 7749 u64 index = 0; 7750 7751 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 7752 new_dirid, new_dirid, 7753 S_IFDIR | (~current_umask() & S_IRWXUGO), 7754 &index); 7755 if (IS_ERR(inode)) 7756 return PTR_ERR(inode); 7757 inode->i_op = &btrfs_dir_inode_operations; 7758 inode->i_fop = &btrfs_dir_file_operations; 7759 7760 set_nlink(inode, 1); 7761 btrfs_i_size_write(inode, 0); 7762 7763 err = btrfs_update_inode(trans, new_root, inode); 7764 7765 iput(inode); 7766 return err; 7767 } 7768 7769 struct inode *btrfs_alloc_inode(struct super_block *sb) 7770 { 7771 struct btrfs_inode *ei; 7772 struct inode *inode; 7773 7774 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 7775 if (!ei) 7776 return NULL; 7777 7778 ei->root = NULL; 7779 ei->generation = 0; 7780 ei->last_trans = 0; 7781 ei->last_sub_trans = 0; 7782 ei->logged_trans = 0; 7783 ei->delalloc_bytes = 0; 7784 ei->disk_i_size = 0; 7785 ei->flags = 0; 7786 ei->csum_bytes = 0; 7787 ei->index_cnt = (u64)-1; 7788 ei->last_unlink_trans = 0; 7789 ei->last_log_commit = 0; 7790 7791 spin_lock_init(&ei->lock); 7792 ei->outstanding_extents = 0; 7793 ei->reserved_extents = 0; 7794 7795 ei->runtime_flags = 0; 7796 ei->force_compress = BTRFS_COMPRESS_NONE; 7797 7798 ei->delayed_node = NULL; 7799 7800 inode = &ei->vfs_inode; 7801 extent_map_tree_init(&ei->extent_tree); 7802 extent_io_tree_init(&ei->io_tree, &inode->i_data); 7803 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 7804 ei->io_tree.track_uptodate = 1; 7805 ei->io_failure_tree.track_uptodate = 1; 7806 atomic_set(&ei->sync_writers, 0); 7807 mutex_init(&ei->log_mutex); 7808 mutex_init(&ei->delalloc_mutex); 7809 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 7810 INIT_LIST_HEAD(&ei->delalloc_inodes); 7811 INIT_LIST_HEAD(&ei->ordered_operations); 7812 RB_CLEAR_NODE(&ei->rb_node); 7813 7814 return inode; 7815 } 7816 7817 static void btrfs_i_callback(struct rcu_head *head) 7818 { 7819 struct inode *inode = container_of(head, struct inode, i_rcu); 7820 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 7821 } 7822 7823 void btrfs_destroy_inode(struct inode *inode) 7824 { 7825 struct btrfs_ordered_extent *ordered; 7826 struct btrfs_root *root = BTRFS_I(inode)->root; 7827 7828 WARN_ON(!hlist_empty(&inode->i_dentry)); 7829 WARN_ON(inode->i_data.nrpages); 7830 WARN_ON(BTRFS_I(inode)->outstanding_extents); 7831 WARN_ON(BTRFS_I(inode)->reserved_extents); 7832 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 7833 WARN_ON(BTRFS_I(inode)->csum_bytes); 7834 7835 /* 7836 * This can happen where we create an inode, but somebody else also 7837 * created the same inode and we need to destroy the one we already 7838 * created. 7839 */ 7840 if (!root) 7841 goto free; 7842 7843 /* 7844 * Make sure we're properly removed from the ordered operation 7845 * lists. 7846 */ 7847 smp_mb(); 7848 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) { 7849 spin_lock(&root->fs_info->ordered_root_lock); 7850 list_del_init(&BTRFS_I(inode)->ordered_operations); 7851 spin_unlock(&root->fs_info->ordered_root_lock); 7852 } 7853 7854 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 7855 &BTRFS_I(inode)->runtime_flags)) { 7856 btrfs_info(root->fs_info, "inode %llu still on the orphan list", 7857 (unsigned long long)btrfs_ino(inode)); 7858 atomic_dec(&root->orphan_inodes); 7859 } 7860 7861 while (1) { 7862 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 7863 if (!ordered) 7864 break; 7865 else { 7866 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", 7867 (unsigned long long)ordered->file_offset, 7868 (unsigned long long)ordered->len); 7869 btrfs_remove_ordered_extent(inode, ordered); 7870 btrfs_put_ordered_extent(ordered); 7871 btrfs_put_ordered_extent(ordered); 7872 } 7873 } 7874 inode_tree_del(inode); 7875 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 7876 free: 7877 call_rcu(&inode->i_rcu, btrfs_i_callback); 7878 } 7879 7880 int btrfs_drop_inode(struct inode *inode) 7881 { 7882 struct btrfs_root *root = BTRFS_I(inode)->root; 7883 7884 if (root == NULL) 7885 return 1; 7886 7887 /* the snap/subvol tree is on deleting */ 7888 if (btrfs_root_refs(&root->root_item) == 0 && 7889 root != root->fs_info->tree_root) 7890 return 1; 7891 else 7892 return generic_drop_inode(inode); 7893 } 7894 7895 static void init_once(void *foo) 7896 { 7897 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 7898 7899 inode_init_once(&ei->vfs_inode); 7900 } 7901 7902 void btrfs_destroy_cachep(void) 7903 { 7904 /* 7905 * Make sure all delayed rcu free inodes are flushed before we 7906 * destroy cache. 7907 */ 7908 rcu_barrier(); 7909 if (btrfs_inode_cachep) 7910 kmem_cache_destroy(btrfs_inode_cachep); 7911 if (btrfs_trans_handle_cachep) 7912 kmem_cache_destroy(btrfs_trans_handle_cachep); 7913 if (btrfs_transaction_cachep) 7914 kmem_cache_destroy(btrfs_transaction_cachep); 7915 if (btrfs_path_cachep) 7916 kmem_cache_destroy(btrfs_path_cachep); 7917 if (btrfs_free_space_cachep) 7918 kmem_cache_destroy(btrfs_free_space_cachep); 7919 if (btrfs_delalloc_work_cachep) 7920 kmem_cache_destroy(btrfs_delalloc_work_cachep); 7921 } 7922 7923 int btrfs_init_cachep(void) 7924 { 7925 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 7926 sizeof(struct btrfs_inode), 0, 7927 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); 7928 if (!btrfs_inode_cachep) 7929 goto fail; 7930 7931 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 7932 sizeof(struct btrfs_trans_handle), 0, 7933 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 7934 if (!btrfs_trans_handle_cachep) 7935 goto fail; 7936 7937 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 7938 sizeof(struct btrfs_transaction), 0, 7939 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 7940 if (!btrfs_transaction_cachep) 7941 goto fail; 7942 7943 btrfs_path_cachep = kmem_cache_create("btrfs_path", 7944 sizeof(struct btrfs_path), 0, 7945 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 7946 if (!btrfs_path_cachep) 7947 goto fail; 7948 7949 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 7950 sizeof(struct btrfs_free_space), 0, 7951 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 7952 if (!btrfs_free_space_cachep) 7953 goto fail; 7954 7955 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work", 7956 sizeof(struct btrfs_delalloc_work), 0, 7957 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 7958 NULL); 7959 if (!btrfs_delalloc_work_cachep) 7960 goto fail; 7961 7962 return 0; 7963 fail: 7964 btrfs_destroy_cachep(); 7965 return -ENOMEM; 7966 } 7967 7968 static int btrfs_getattr(struct vfsmount *mnt, 7969 struct dentry *dentry, struct kstat *stat) 7970 { 7971 u64 delalloc_bytes; 7972 struct inode *inode = dentry->d_inode; 7973 u32 blocksize = inode->i_sb->s_blocksize; 7974 7975 generic_fillattr(inode, stat); 7976 stat->dev = BTRFS_I(inode)->root->anon_dev; 7977 stat->blksize = PAGE_CACHE_SIZE; 7978 7979 spin_lock(&BTRFS_I(inode)->lock); 7980 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 7981 spin_unlock(&BTRFS_I(inode)->lock); 7982 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 7983 ALIGN(delalloc_bytes, blocksize)) >> 9; 7984 return 0; 7985 } 7986 7987 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 7988 struct inode *new_dir, struct dentry *new_dentry) 7989 { 7990 struct btrfs_trans_handle *trans; 7991 struct btrfs_root *root = BTRFS_I(old_dir)->root; 7992 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 7993 struct inode *new_inode = new_dentry->d_inode; 7994 struct inode *old_inode = old_dentry->d_inode; 7995 struct timespec ctime = CURRENT_TIME; 7996 u64 index = 0; 7997 u64 root_objectid; 7998 int ret; 7999 u64 old_ino = btrfs_ino(old_inode); 8000 8001 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 8002 return -EPERM; 8003 8004 /* we only allow rename subvolume link between subvolumes */ 8005 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 8006 return -EXDEV; 8007 8008 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 8009 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) 8010 return -ENOTEMPTY; 8011 8012 if (S_ISDIR(old_inode->i_mode) && new_inode && 8013 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 8014 return -ENOTEMPTY; 8015 8016 8017 /* check for collisions, even if the name isn't there */ 8018 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino, 8019 new_dentry->d_name.name, 8020 new_dentry->d_name.len); 8021 8022 if (ret) { 8023 if (ret == -EEXIST) { 8024 /* we shouldn't get 8025 * eexist without a new_inode */ 8026 if (!new_inode) { 8027 WARN_ON(1); 8028 return ret; 8029 } 8030 } else { 8031 /* maybe -EOVERFLOW */ 8032 return ret; 8033 } 8034 } 8035 ret = 0; 8036 8037 /* 8038 * we're using rename to replace one file with another. 8039 * and the replacement file is large. Start IO on it now so 8040 * we don't add too much work to the end of the transaction 8041 */ 8042 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size && 8043 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) 8044 filemap_flush(old_inode->i_mapping); 8045 8046 /* close the racy window with snapshot create/destroy ioctl */ 8047 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8048 down_read(&root->fs_info->subvol_sem); 8049 /* 8050 * We want to reserve the absolute worst case amount of items. So if 8051 * both inodes are subvols and we need to unlink them then that would 8052 * require 4 item modifications, but if they are both normal inodes it 8053 * would require 5 item modifications, so we'll assume their normal 8054 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 8055 * should cover the worst case number of items we'll modify. 8056 */ 8057 trans = btrfs_start_transaction(root, 11); 8058 if (IS_ERR(trans)) { 8059 ret = PTR_ERR(trans); 8060 goto out_notrans; 8061 } 8062 8063 if (dest != root) 8064 btrfs_record_root_in_trans(trans, dest); 8065 8066 ret = btrfs_set_inode_index(new_dir, &index); 8067 if (ret) 8068 goto out_fail; 8069 8070 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8071 /* force full log commit if subvolume involved. */ 8072 root->fs_info->last_trans_log_full_commit = trans->transid; 8073 } else { 8074 ret = btrfs_insert_inode_ref(trans, dest, 8075 new_dentry->d_name.name, 8076 new_dentry->d_name.len, 8077 old_ino, 8078 btrfs_ino(new_dir), index); 8079 if (ret) 8080 goto out_fail; 8081 /* 8082 * this is an ugly little race, but the rename is required 8083 * to make sure that if we crash, the inode is either at the 8084 * old name or the new one. pinning the log transaction lets 8085 * us make sure we don't allow a log commit to come in after 8086 * we unlink the name but before we add the new name back in. 8087 */ 8088 btrfs_pin_log_trans(root); 8089 } 8090 /* 8091 * make sure the inode gets flushed if it is replacing 8092 * something. 8093 */ 8094 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode)) 8095 btrfs_add_ordered_operation(trans, root, old_inode); 8096 8097 inode_inc_iversion(old_dir); 8098 inode_inc_iversion(new_dir); 8099 inode_inc_iversion(old_inode); 8100 old_dir->i_ctime = old_dir->i_mtime = ctime; 8101 new_dir->i_ctime = new_dir->i_mtime = ctime; 8102 old_inode->i_ctime = ctime; 8103 8104 if (old_dentry->d_parent != new_dentry->d_parent) 8105 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); 8106 8107 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8108 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 8109 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 8110 old_dentry->d_name.name, 8111 old_dentry->d_name.len); 8112 } else { 8113 ret = __btrfs_unlink_inode(trans, root, old_dir, 8114 old_dentry->d_inode, 8115 old_dentry->d_name.name, 8116 old_dentry->d_name.len); 8117 if (!ret) 8118 ret = btrfs_update_inode(trans, root, old_inode); 8119 } 8120 if (ret) { 8121 btrfs_abort_transaction(trans, root, ret); 8122 goto out_fail; 8123 } 8124 8125 if (new_inode) { 8126 inode_inc_iversion(new_inode); 8127 new_inode->i_ctime = CURRENT_TIME; 8128 if (unlikely(btrfs_ino(new_inode) == 8129 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 8130 root_objectid = BTRFS_I(new_inode)->location.objectid; 8131 ret = btrfs_unlink_subvol(trans, dest, new_dir, 8132 root_objectid, 8133 new_dentry->d_name.name, 8134 new_dentry->d_name.len); 8135 BUG_ON(new_inode->i_nlink == 0); 8136 } else { 8137 ret = btrfs_unlink_inode(trans, dest, new_dir, 8138 new_dentry->d_inode, 8139 new_dentry->d_name.name, 8140 new_dentry->d_name.len); 8141 } 8142 if (!ret && new_inode->i_nlink == 0) { 8143 ret = btrfs_orphan_add(trans, new_dentry->d_inode); 8144 BUG_ON(ret); 8145 } 8146 if (ret) { 8147 btrfs_abort_transaction(trans, root, ret); 8148 goto out_fail; 8149 } 8150 } 8151 8152 ret = btrfs_add_link(trans, new_dir, old_inode, 8153 new_dentry->d_name.name, 8154 new_dentry->d_name.len, 0, index); 8155 if (ret) { 8156 btrfs_abort_transaction(trans, root, ret); 8157 goto out_fail; 8158 } 8159 8160 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { 8161 struct dentry *parent = new_dentry->d_parent; 8162 btrfs_log_new_name(trans, old_inode, old_dir, parent); 8163 btrfs_end_log_trans(root); 8164 } 8165 out_fail: 8166 btrfs_end_transaction(trans, root); 8167 out_notrans: 8168 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8169 up_read(&root->fs_info->subvol_sem); 8170 8171 return ret; 8172 } 8173 8174 static void btrfs_run_delalloc_work(struct btrfs_work *work) 8175 { 8176 struct btrfs_delalloc_work *delalloc_work; 8177 8178 delalloc_work = container_of(work, struct btrfs_delalloc_work, 8179 work); 8180 if (delalloc_work->wait) 8181 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1); 8182 else 8183 filemap_flush(delalloc_work->inode->i_mapping); 8184 8185 if (delalloc_work->delay_iput) 8186 btrfs_add_delayed_iput(delalloc_work->inode); 8187 else 8188 iput(delalloc_work->inode); 8189 complete(&delalloc_work->completion); 8190 } 8191 8192 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 8193 int wait, int delay_iput) 8194 { 8195 struct btrfs_delalloc_work *work; 8196 8197 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS); 8198 if (!work) 8199 return NULL; 8200 8201 init_completion(&work->completion); 8202 INIT_LIST_HEAD(&work->list); 8203 work->inode = inode; 8204 work->wait = wait; 8205 work->delay_iput = delay_iput; 8206 work->work.func = btrfs_run_delalloc_work; 8207 8208 return work; 8209 } 8210 8211 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 8212 { 8213 wait_for_completion(&work->completion); 8214 kmem_cache_free(btrfs_delalloc_work_cachep, work); 8215 } 8216 8217 /* 8218 * some fairly slow code that needs optimization. This walks the list 8219 * of all the inodes with pending delalloc and forces them to disk. 8220 */ 8221 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8222 { 8223 struct btrfs_inode *binode; 8224 struct inode *inode; 8225 struct btrfs_delalloc_work *work, *next; 8226 struct list_head works; 8227 struct list_head splice; 8228 int ret = 0; 8229 8230 INIT_LIST_HEAD(&works); 8231 INIT_LIST_HEAD(&splice); 8232 8233 spin_lock(&root->delalloc_lock); 8234 list_splice_init(&root->delalloc_inodes, &splice); 8235 while (!list_empty(&splice)) { 8236 binode = list_entry(splice.next, struct btrfs_inode, 8237 delalloc_inodes); 8238 8239 list_move_tail(&binode->delalloc_inodes, 8240 &root->delalloc_inodes); 8241 inode = igrab(&binode->vfs_inode); 8242 if (!inode) { 8243 cond_resched_lock(&root->delalloc_lock); 8244 continue; 8245 } 8246 spin_unlock(&root->delalloc_lock); 8247 8248 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput); 8249 if (unlikely(!work)) { 8250 ret = -ENOMEM; 8251 goto out; 8252 } 8253 list_add_tail(&work->list, &works); 8254 btrfs_queue_worker(&root->fs_info->flush_workers, 8255 &work->work); 8256 8257 cond_resched(); 8258 spin_lock(&root->delalloc_lock); 8259 } 8260 spin_unlock(&root->delalloc_lock); 8261 8262 list_for_each_entry_safe(work, next, &works, list) { 8263 list_del_init(&work->list); 8264 btrfs_wait_and_free_delalloc_work(work); 8265 } 8266 return 0; 8267 out: 8268 list_for_each_entry_safe(work, next, &works, list) { 8269 list_del_init(&work->list); 8270 btrfs_wait_and_free_delalloc_work(work); 8271 } 8272 8273 if (!list_empty_careful(&splice)) { 8274 spin_lock(&root->delalloc_lock); 8275 list_splice_tail(&splice, &root->delalloc_inodes); 8276 spin_unlock(&root->delalloc_lock); 8277 } 8278 return ret; 8279 } 8280 8281 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8282 { 8283 int ret; 8284 8285 if (root->fs_info->sb->s_flags & MS_RDONLY) 8286 return -EROFS; 8287 8288 ret = __start_delalloc_inodes(root, delay_iput); 8289 /* 8290 * the filemap_flush will queue IO into the worker threads, but 8291 * we have to make sure the IO is actually started and that 8292 * ordered extents get created before we return 8293 */ 8294 atomic_inc(&root->fs_info->async_submit_draining); 8295 while (atomic_read(&root->fs_info->nr_async_submits) || 8296 atomic_read(&root->fs_info->async_delalloc_pages)) { 8297 wait_event(root->fs_info->async_submit_wait, 8298 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 8299 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 8300 } 8301 atomic_dec(&root->fs_info->async_submit_draining); 8302 return ret; 8303 } 8304 8305 int btrfs_start_all_delalloc_inodes(struct btrfs_fs_info *fs_info, 8306 int delay_iput) 8307 { 8308 struct btrfs_root *root; 8309 struct list_head splice; 8310 int ret; 8311 8312 if (fs_info->sb->s_flags & MS_RDONLY) 8313 return -EROFS; 8314 8315 INIT_LIST_HEAD(&splice); 8316 8317 spin_lock(&fs_info->delalloc_root_lock); 8318 list_splice_init(&fs_info->delalloc_roots, &splice); 8319 while (!list_empty(&splice)) { 8320 root = list_first_entry(&splice, struct btrfs_root, 8321 delalloc_root); 8322 root = btrfs_grab_fs_root(root); 8323 BUG_ON(!root); 8324 list_move_tail(&root->delalloc_root, 8325 &fs_info->delalloc_roots); 8326 spin_unlock(&fs_info->delalloc_root_lock); 8327 8328 ret = __start_delalloc_inodes(root, delay_iput); 8329 btrfs_put_fs_root(root); 8330 if (ret) 8331 goto out; 8332 8333 spin_lock(&fs_info->delalloc_root_lock); 8334 } 8335 spin_unlock(&fs_info->delalloc_root_lock); 8336 8337 atomic_inc(&fs_info->async_submit_draining); 8338 while (atomic_read(&fs_info->nr_async_submits) || 8339 atomic_read(&fs_info->async_delalloc_pages)) { 8340 wait_event(fs_info->async_submit_wait, 8341 (atomic_read(&fs_info->nr_async_submits) == 0 && 8342 atomic_read(&fs_info->async_delalloc_pages) == 0)); 8343 } 8344 atomic_dec(&fs_info->async_submit_draining); 8345 return 0; 8346 out: 8347 if (!list_empty_careful(&splice)) { 8348 spin_lock(&fs_info->delalloc_root_lock); 8349 list_splice_tail(&splice, &fs_info->delalloc_roots); 8350 spin_unlock(&fs_info->delalloc_root_lock); 8351 } 8352 return ret; 8353 } 8354 8355 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 8356 const char *symname) 8357 { 8358 struct btrfs_trans_handle *trans; 8359 struct btrfs_root *root = BTRFS_I(dir)->root; 8360 struct btrfs_path *path; 8361 struct btrfs_key key; 8362 struct inode *inode = NULL; 8363 int err; 8364 int drop_inode = 0; 8365 u64 objectid; 8366 u64 index = 0 ; 8367 int name_len; 8368 int datasize; 8369 unsigned long ptr; 8370 struct btrfs_file_extent_item *ei; 8371 struct extent_buffer *leaf; 8372 8373 name_len = strlen(symname) + 1; 8374 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) 8375 return -ENAMETOOLONG; 8376 8377 /* 8378 * 2 items for inode item and ref 8379 * 2 items for dir items 8380 * 1 item for xattr if selinux is on 8381 */ 8382 trans = btrfs_start_transaction(root, 5); 8383 if (IS_ERR(trans)) 8384 return PTR_ERR(trans); 8385 8386 err = btrfs_find_free_ino(root, &objectid); 8387 if (err) 8388 goto out_unlock; 8389 8390 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 8391 dentry->d_name.len, btrfs_ino(dir), objectid, 8392 S_IFLNK|S_IRWXUGO, &index); 8393 if (IS_ERR(inode)) { 8394 err = PTR_ERR(inode); 8395 goto out_unlock; 8396 } 8397 8398 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 8399 if (err) { 8400 drop_inode = 1; 8401 goto out_unlock; 8402 } 8403 8404 /* 8405 * If the active LSM wants to access the inode during 8406 * d_instantiate it needs these. Smack checks to see 8407 * if the filesystem supports xattrs by looking at the 8408 * ops vector. 8409 */ 8410 inode->i_fop = &btrfs_file_operations; 8411 inode->i_op = &btrfs_file_inode_operations; 8412 8413 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 8414 if (err) 8415 drop_inode = 1; 8416 else { 8417 inode->i_mapping->a_ops = &btrfs_aops; 8418 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8419 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 8420 } 8421 if (drop_inode) 8422 goto out_unlock; 8423 8424 path = btrfs_alloc_path(); 8425 if (!path) { 8426 err = -ENOMEM; 8427 drop_inode = 1; 8428 goto out_unlock; 8429 } 8430 key.objectid = btrfs_ino(inode); 8431 key.offset = 0; 8432 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 8433 datasize = btrfs_file_extent_calc_inline_size(name_len); 8434 err = btrfs_insert_empty_item(trans, root, path, &key, 8435 datasize); 8436 if (err) { 8437 drop_inode = 1; 8438 btrfs_free_path(path); 8439 goto out_unlock; 8440 } 8441 leaf = path->nodes[0]; 8442 ei = btrfs_item_ptr(leaf, path->slots[0], 8443 struct btrfs_file_extent_item); 8444 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 8445 btrfs_set_file_extent_type(leaf, ei, 8446 BTRFS_FILE_EXTENT_INLINE); 8447 btrfs_set_file_extent_encryption(leaf, ei, 0); 8448 btrfs_set_file_extent_compression(leaf, ei, 0); 8449 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 8450 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 8451 8452 ptr = btrfs_file_extent_inline_start(ei); 8453 write_extent_buffer(leaf, symname, ptr, name_len); 8454 btrfs_mark_buffer_dirty(leaf); 8455 btrfs_free_path(path); 8456 8457 inode->i_op = &btrfs_symlink_inode_operations; 8458 inode->i_mapping->a_ops = &btrfs_symlink_aops; 8459 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8460 inode_set_bytes(inode, name_len); 8461 btrfs_i_size_write(inode, name_len - 1); 8462 err = btrfs_update_inode(trans, root, inode); 8463 if (err) 8464 drop_inode = 1; 8465 8466 out_unlock: 8467 if (!err) 8468 d_instantiate(dentry, inode); 8469 btrfs_end_transaction(trans, root); 8470 if (drop_inode) { 8471 inode_dec_link_count(inode); 8472 iput(inode); 8473 } 8474 btrfs_btree_balance_dirty(root); 8475 return err; 8476 } 8477 8478 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 8479 u64 start, u64 num_bytes, u64 min_size, 8480 loff_t actual_len, u64 *alloc_hint, 8481 struct btrfs_trans_handle *trans) 8482 { 8483 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 8484 struct extent_map *em; 8485 struct btrfs_root *root = BTRFS_I(inode)->root; 8486 struct btrfs_key ins; 8487 u64 cur_offset = start; 8488 u64 i_size; 8489 u64 cur_bytes; 8490 int ret = 0; 8491 bool own_trans = true; 8492 8493 if (trans) 8494 own_trans = false; 8495 while (num_bytes > 0) { 8496 if (own_trans) { 8497 trans = btrfs_start_transaction(root, 3); 8498 if (IS_ERR(trans)) { 8499 ret = PTR_ERR(trans); 8500 break; 8501 } 8502 } 8503 8504 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024); 8505 cur_bytes = max(cur_bytes, min_size); 8506 ret = btrfs_reserve_extent(trans, root, cur_bytes, 8507 min_size, 0, *alloc_hint, &ins, 1); 8508 if (ret) { 8509 if (own_trans) 8510 btrfs_end_transaction(trans, root); 8511 break; 8512 } 8513 8514 ret = insert_reserved_file_extent(trans, inode, 8515 cur_offset, ins.objectid, 8516 ins.offset, ins.offset, 8517 ins.offset, 0, 0, 0, 8518 BTRFS_FILE_EXTENT_PREALLOC); 8519 if (ret) { 8520 btrfs_abort_transaction(trans, root, ret); 8521 if (own_trans) 8522 btrfs_end_transaction(trans, root); 8523 break; 8524 } 8525 btrfs_drop_extent_cache(inode, cur_offset, 8526 cur_offset + ins.offset -1, 0); 8527 8528 em = alloc_extent_map(); 8529 if (!em) { 8530 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 8531 &BTRFS_I(inode)->runtime_flags); 8532 goto next; 8533 } 8534 8535 em->start = cur_offset; 8536 em->orig_start = cur_offset; 8537 em->len = ins.offset; 8538 em->block_start = ins.objectid; 8539 em->block_len = ins.offset; 8540 em->orig_block_len = ins.offset; 8541 em->ram_bytes = ins.offset; 8542 em->bdev = root->fs_info->fs_devices->latest_bdev; 8543 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 8544 em->generation = trans->transid; 8545 8546 while (1) { 8547 write_lock(&em_tree->lock); 8548 ret = add_extent_mapping(em_tree, em, 1); 8549 write_unlock(&em_tree->lock); 8550 if (ret != -EEXIST) 8551 break; 8552 btrfs_drop_extent_cache(inode, cur_offset, 8553 cur_offset + ins.offset - 1, 8554 0); 8555 } 8556 free_extent_map(em); 8557 next: 8558 num_bytes -= ins.offset; 8559 cur_offset += ins.offset; 8560 *alloc_hint = ins.objectid + ins.offset; 8561 8562 inode_inc_iversion(inode); 8563 inode->i_ctime = CURRENT_TIME; 8564 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 8565 if (!(mode & FALLOC_FL_KEEP_SIZE) && 8566 (actual_len > inode->i_size) && 8567 (cur_offset > inode->i_size)) { 8568 if (cur_offset > actual_len) 8569 i_size = actual_len; 8570 else 8571 i_size = cur_offset; 8572 i_size_write(inode, i_size); 8573 btrfs_ordered_update_i_size(inode, i_size, NULL); 8574 } 8575 8576 ret = btrfs_update_inode(trans, root, inode); 8577 8578 if (ret) { 8579 btrfs_abort_transaction(trans, root, ret); 8580 if (own_trans) 8581 btrfs_end_transaction(trans, root); 8582 break; 8583 } 8584 8585 if (own_trans) 8586 btrfs_end_transaction(trans, root); 8587 } 8588 return ret; 8589 } 8590 8591 int btrfs_prealloc_file_range(struct inode *inode, int mode, 8592 u64 start, u64 num_bytes, u64 min_size, 8593 loff_t actual_len, u64 *alloc_hint) 8594 { 8595 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8596 min_size, actual_len, alloc_hint, 8597 NULL); 8598 } 8599 8600 int btrfs_prealloc_file_range_trans(struct inode *inode, 8601 struct btrfs_trans_handle *trans, int mode, 8602 u64 start, u64 num_bytes, u64 min_size, 8603 loff_t actual_len, u64 *alloc_hint) 8604 { 8605 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8606 min_size, actual_len, alloc_hint, trans); 8607 } 8608 8609 static int btrfs_set_page_dirty(struct page *page) 8610 { 8611 return __set_page_dirty_nobuffers(page); 8612 } 8613 8614 static int btrfs_permission(struct inode *inode, int mask) 8615 { 8616 struct btrfs_root *root = BTRFS_I(inode)->root; 8617 umode_t mode = inode->i_mode; 8618 8619 if (mask & MAY_WRITE && 8620 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 8621 if (btrfs_root_readonly(root)) 8622 return -EROFS; 8623 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 8624 return -EACCES; 8625 } 8626 return generic_permission(inode, mask); 8627 } 8628 8629 static const struct inode_operations btrfs_dir_inode_operations = { 8630 .getattr = btrfs_getattr, 8631 .lookup = btrfs_lookup, 8632 .create = btrfs_create, 8633 .unlink = btrfs_unlink, 8634 .link = btrfs_link, 8635 .mkdir = btrfs_mkdir, 8636 .rmdir = btrfs_rmdir, 8637 .rename = btrfs_rename, 8638 .symlink = btrfs_symlink, 8639 .setattr = btrfs_setattr, 8640 .mknod = btrfs_mknod, 8641 .setxattr = btrfs_setxattr, 8642 .getxattr = btrfs_getxattr, 8643 .listxattr = btrfs_listxattr, 8644 .removexattr = btrfs_removexattr, 8645 .permission = btrfs_permission, 8646 .get_acl = btrfs_get_acl, 8647 }; 8648 static const struct inode_operations btrfs_dir_ro_inode_operations = { 8649 .lookup = btrfs_lookup, 8650 .permission = btrfs_permission, 8651 .get_acl = btrfs_get_acl, 8652 }; 8653 8654 static const struct file_operations btrfs_dir_file_operations = { 8655 .llseek = generic_file_llseek, 8656 .read = generic_read_dir, 8657 .iterate = btrfs_real_readdir, 8658 .unlocked_ioctl = btrfs_ioctl, 8659 #ifdef CONFIG_COMPAT 8660 .compat_ioctl = btrfs_ioctl, 8661 #endif 8662 .release = btrfs_release_file, 8663 .fsync = btrfs_sync_file, 8664 }; 8665 8666 static struct extent_io_ops btrfs_extent_io_ops = { 8667 .fill_delalloc = run_delalloc_range, 8668 .submit_bio_hook = btrfs_submit_bio_hook, 8669 .merge_bio_hook = btrfs_merge_bio_hook, 8670 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 8671 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 8672 .writepage_start_hook = btrfs_writepage_start_hook, 8673 .set_bit_hook = btrfs_set_bit_hook, 8674 .clear_bit_hook = btrfs_clear_bit_hook, 8675 .merge_extent_hook = btrfs_merge_extent_hook, 8676 .split_extent_hook = btrfs_split_extent_hook, 8677 }; 8678 8679 /* 8680 * btrfs doesn't support the bmap operation because swapfiles 8681 * use bmap to make a mapping of extents in the file. They assume 8682 * these extents won't change over the life of the file and they 8683 * use the bmap result to do IO directly to the drive. 8684 * 8685 * the btrfs bmap call would return logical addresses that aren't 8686 * suitable for IO and they also will change frequently as COW 8687 * operations happen. So, swapfile + btrfs == corruption. 8688 * 8689 * For now we're avoiding this by dropping bmap. 8690 */ 8691 static const struct address_space_operations btrfs_aops = { 8692 .readpage = btrfs_readpage, 8693 .writepage = btrfs_writepage, 8694 .writepages = btrfs_writepages, 8695 .readpages = btrfs_readpages, 8696 .direct_IO = btrfs_direct_IO, 8697 .invalidatepage = btrfs_invalidatepage, 8698 .releasepage = btrfs_releasepage, 8699 .set_page_dirty = btrfs_set_page_dirty, 8700 .error_remove_page = generic_error_remove_page, 8701 }; 8702 8703 static const struct address_space_operations btrfs_symlink_aops = { 8704 .readpage = btrfs_readpage, 8705 .writepage = btrfs_writepage, 8706 .invalidatepage = btrfs_invalidatepage, 8707 .releasepage = btrfs_releasepage, 8708 }; 8709 8710 static const struct inode_operations btrfs_file_inode_operations = { 8711 .getattr = btrfs_getattr, 8712 .setattr = btrfs_setattr, 8713 .setxattr = btrfs_setxattr, 8714 .getxattr = btrfs_getxattr, 8715 .listxattr = btrfs_listxattr, 8716 .removexattr = btrfs_removexattr, 8717 .permission = btrfs_permission, 8718 .fiemap = btrfs_fiemap, 8719 .get_acl = btrfs_get_acl, 8720 .update_time = btrfs_update_time, 8721 }; 8722 static const struct inode_operations btrfs_special_inode_operations = { 8723 .getattr = btrfs_getattr, 8724 .setattr = btrfs_setattr, 8725 .permission = btrfs_permission, 8726 .setxattr = btrfs_setxattr, 8727 .getxattr = btrfs_getxattr, 8728 .listxattr = btrfs_listxattr, 8729 .removexattr = btrfs_removexattr, 8730 .get_acl = btrfs_get_acl, 8731 .update_time = btrfs_update_time, 8732 }; 8733 static const struct inode_operations btrfs_symlink_inode_operations = { 8734 .readlink = generic_readlink, 8735 .follow_link = page_follow_link_light, 8736 .put_link = page_put_link, 8737 .getattr = btrfs_getattr, 8738 .setattr = btrfs_setattr, 8739 .permission = btrfs_permission, 8740 .setxattr = btrfs_setxattr, 8741 .getxattr = btrfs_getxattr, 8742 .listxattr = btrfs_listxattr, 8743 .removexattr = btrfs_removexattr, 8744 .get_acl = btrfs_get_acl, 8745 .update_time = btrfs_update_time, 8746 }; 8747 8748 const struct dentry_operations btrfs_dentry_operations = { 8749 .d_delete = btrfs_dentry_delete, 8750 .d_release = btrfs_dentry_release, 8751 }; 8752