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/fs.h> 20 #include <linux/blkdev.h> 21 #include <linux/scatterlist.h> 22 #include <linux/swap.h> 23 #include <linux/radix-tree.h> 24 #include <linux/writeback.h> 25 #include <linux/buffer_head.h> 26 #include <linux/workqueue.h> 27 #include <linux/kthread.h> 28 #include <linux/freezer.h> 29 #include <linux/crc32c.h> 30 #include <linux/slab.h> 31 #include "compat.h" 32 #include "ctree.h" 33 #include "disk-io.h" 34 #include "transaction.h" 35 #include "btrfs_inode.h" 36 #include "volumes.h" 37 #include "print-tree.h" 38 #include "async-thread.h" 39 #include "locking.h" 40 #include "tree-log.h" 41 #include "free-space-cache.h" 42 43 static struct extent_io_ops btree_extent_io_ops; 44 static void end_workqueue_fn(struct btrfs_work *work); 45 static void free_fs_root(struct btrfs_root *root); 46 47 static atomic_t btrfs_bdi_num = ATOMIC_INIT(0); 48 49 /* 50 * end_io_wq structs are used to do processing in task context when an IO is 51 * complete. This is used during reads to verify checksums, and it is used 52 * by writes to insert metadata for new file extents after IO is complete. 53 */ 54 struct end_io_wq { 55 struct bio *bio; 56 bio_end_io_t *end_io; 57 void *private; 58 struct btrfs_fs_info *info; 59 int error; 60 int metadata; 61 struct list_head list; 62 struct btrfs_work work; 63 }; 64 65 /* 66 * async submit bios are used to offload expensive checksumming 67 * onto the worker threads. They checksum file and metadata bios 68 * just before they are sent down the IO stack. 69 */ 70 struct async_submit_bio { 71 struct inode *inode; 72 struct bio *bio; 73 struct list_head list; 74 extent_submit_bio_hook_t *submit_bio_start; 75 extent_submit_bio_hook_t *submit_bio_done; 76 int rw; 77 int mirror_num; 78 unsigned long bio_flags; 79 struct btrfs_work work; 80 }; 81 82 /* These are used to set the lockdep class on the extent buffer locks. 83 * The class is set by the readpage_end_io_hook after the buffer has 84 * passed csum validation but before the pages are unlocked. 85 * 86 * The lockdep class is also set by btrfs_init_new_buffer on freshly 87 * allocated blocks. 88 * 89 * The class is based on the level in the tree block, which allows lockdep 90 * to know that lower nodes nest inside the locks of higher nodes. 91 * 92 * We also add a check to make sure the highest level of the tree is 93 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this 94 * code needs update as well. 95 */ 96 #ifdef CONFIG_DEBUG_LOCK_ALLOC 97 # if BTRFS_MAX_LEVEL != 8 98 # error 99 # endif 100 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1]; 101 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = { 102 /* leaf */ 103 "btrfs-extent-00", 104 "btrfs-extent-01", 105 "btrfs-extent-02", 106 "btrfs-extent-03", 107 "btrfs-extent-04", 108 "btrfs-extent-05", 109 "btrfs-extent-06", 110 "btrfs-extent-07", 111 /* highest possible level */ 112 "btrfs-extent-08", 113 }; 114 #endif 115 116 /* 117 * extents on the btree inode are pretty simple, there's one extent 118 * that covers the entire device 119 */ 120 static struct extent_map *btree_get_extent(struct inode *inode, 121 struct page *page, size_t page_offset, u64 start, u64 len, 122 int create) 123 { 124 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 125 struct extent_map *em; 126 int ret; 127 128 read_lock(&em_tree->lock); 129 em = lookup_extent_mapping(em_tree, start, len); 130 if (em) { 131 em->bdev = 132 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; 133 read_unlock(&em_tree->lock); 134 goto out; 135 } 136 read_unlock(&em_tree->lock); 137 138 em = alloc_extent_map(GFP_NOFS); 139 if (!em) { 140 em = ERR_PTR(-ENOMEM); 141 goto out; 142 } 143 em->start = 0; 144 em->len = (u64)-1; 145 em->block_len = (u64)-1; 146 em->block_start = 0; 147 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; 148 149 write_lock(&em_tree->lock); 150 ret = add_extent_mapping(em_tree, em); 151 if (ret == -EEXIST) { 152 u64 failed_start = em->start; 153 u64 failed_len = em->len; 154 155 free_extent_map(em); 156 em = lookup_extent_mapping(em_tree, start, len); 157 if (em) { 158 ret = 0; 159 } else { 160 em = lookup_extent_mapping(em_tree, failed_start, 161 failed_len); 162 ret = -EIO; 163 } 164 } else if (ret) { 165 free_extent_map(em); 166 em = NULL; 167 } 168 write_unlock(&em_tree->lock); 169 170 if (ret) 171 em = ERR_PTR(ret); 172 out: 173 return em; 174 } 175 176 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len) 177 { 178 return crc32c(seed, data, len); 179 } 180 181 void btrfs_csum_final(u32 crc, char *result) 182 { 183 *(__le32 *)result = ~cpu_to_le32(crc); 184 } 185 186 /* 187 * compute the csum for a btree block, and either verify it or write it 188 * into the csum field of the block. 189 */ 190 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, 191 int verify) 192 { 193 u16 csum_size = 194 btrfs_super_csum_size(&root->fs_info->super_copy); 195 char *result = NULL; 196 unsigned long len; 197 unsigned long cur_len; 198 unsigned long offset = BTRFS_CSUM_SIZE; 199 char *map_token = NULL; 200 char *kaddr; 201 unsigned long map_start; 202 unsigned long map_len; 203 int err; 204 u32 crc = ~(u32)0; 205 unsigned long inline_result; 206 207 len = buf->len - offset; 208 while (len > 0) { 209 err = map_private_extent_buffer(buf, offset, 32, 210 &map_token, &kaddr, 211 &map_start, &map_len, KM_USER0); 212 if (err) 213 return 1; 214 cur_len = min(len, map_len - (offset - map_start)); 215 crc = btrfs_csum_data(root, kaddr + offset - map_start, 216 crc, cur_len); 217 len -= cur_len; 218 offset += cur_len; 219 unmap_extent_buffer(buf, map_token, KM_USER0); 220 } 221 if (csum_size > sizeof(inline_result)) { 222 result = kzalloc(csum_size * sizeof(char), GFP_NOFS); 223 if (!result) 224 return 1; 225 } else { 226 result = (char *)&inline_result; 227 } 228 229 btrfs_csum_final(crc, result); 230 231 if (verify) { 232 if (memcmp_extent_buffer(buf, result, 0, csum_size)) { 233 u32 val; 234 u32 found = 0; 235 memcpy(&found, result, csum_size); 236 237 read_extent_buffer(buf, &val, 0, csum_size); 238 if (printk_ratelimit()) { 239 printk(KERN_INFO "btrfs: %s checksum verify " 240 "failed on %llu wanted %X found %X " 241 "level %d\n", 242 root->fs_info->sb->s_id, 243 (unsigned long long)buf->start, val, found, 244 btrfs_header_level(buf)); 245 } 246 if (result != (char *)&inline_result) 247 kfree(result); 248 return 1; 249 } 250 } else { 251 write_extent_buffer(buf, result, 0, csum_size); 252 } 253 if (result != (char *)&inline_result) 254 kfree(result); 255 return 0; 256 } 257 258 /* 259 * we can't consider a given block up to date unless the transid of the 260 * block matches the transid in the parent node's pointer. This is how we 261 * detect blocks that either didn't get written at all or got written 262 * in the wrong place. 263 */ 264 static int verify_parent_transid(struct extent_io_tree *io_tree, 265 struct extent_buffer *eb, u64 parent_transid) 266 { 267 struct extent_state *cached_state = NULL; 268 int ret; 269 270 if (!parent_transid || btrfs_header_generation(eb) == parent_transid) 271 return 0; 272 273 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1, 274 0, &cached_state, GFP_NOFS); 275 if (extent_buffer_uptodate(io_tree, eb, cached_state) && 276 btrfs_header_generation(eb) == parent_transid) { 277 ret = 0; 278 goto out; 279 } 280 if (printk_ratelimit()) { 281 printk("parent transid verify failed on %llu wanted %llu " 282 "found %llu\n", 283 (unsigned long long)eb->start, 284 (unsigned long long)parent_transid, 285 (unsigned long long)btrfs_header_generation(eb)); 286 } 287 ret = 1; 288 clear_extent_buffer_uptodate(io_tree, eb, &cached_state); 289 out: 290 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1, 291 &cached_state, GFP_NOFS); 292 return ret; 293 } 294 295 /* 296 * helper to read a given tree block, doing retries as required when 297 * the checksums don't match and we have alternate mirrors to try. 298 */ 299 static int btree_read_extent_buffer_pages(struct btrfs_root *root, 300 struct extent_buffer *eb, 301 u64 start, u64 parent_transid) 302 { 303 struct extent_io_tree *io_tree; 304 int ret; 305 int num_copies = 0; 306 int mirror_num = 0; 307 308 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree; 309 while (1) { 310 ret = read_extent_buffer_pages(io_tree, eb, start, 1, 311 btree_get_extent, mirror_num); 312 if (!ret && 313 !verify_parent_transid(io_tree, eb, parent_transid)) 314 return ret; 315 316 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree, 317 eb->start, eb->len); 318 if (num_copies == 1) 319 return ret; 320 321 mirror_num++; 322 if (mirror_num > num_copies) 323 return ret; 324 } 325 return -EIO; 326 } 327 328 /* 329 * checksum a dirty tree block before IO. This has extra checks to make sure 330 * we only fill in the checksum field in the first page of a multi-page block 331 */ 332 333 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page) 334 { 335 struct extent_io_tree *tree; 336 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 337 u64 found_start; 338 int found_level; 339 unsigned long len; 340 struct extent_buffer *eb; 341 int ret; 342 343 tree = &BTRFS_I(page->mapping->host)->io_tree; 344 345 if (page->private == EXTENT_PAGE_PRIVATE) 346 goto out; 347 if (!page->private) 348 goto out; 349 len = page->private >> 2; 350 WARN_ON(len == 0); 351 352 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS); 353 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE, 354 btrfs_header_generation(eb)); 355 BUG_ON(ret); 356 found_start = btrfs_header_bytenr(eb); 357 if (found_start != start) { 358 WARN_ON(1); 359 goto err; 360 } 361 if (eb->first_page != page) { 362 WARN_ON(1); 363 goto err; 364 } 365 if (!PageUptodate(page)) { 366 WARN_ON(1); 367 goto err; 368 } 369 found_level = btrfs_header_level(eb); 370 371 csum_tree_block(root, eb, 0); 372 err: 373 free_extent_buffer(eb); 374 out: 375 return 0; 376 } 377 378 static int check_tree_block_fsid(struct btrfs_root *root, 379 struct extent_buffer *eb) 380 { 381 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 382 u8 fsid[BTRFS_UUID_SIZE]; 383 int ret = 1; 384 385 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb), 386 BTRFS_FSID_SIZE); 387 while (fs_devices) { 388 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) { 389 ret = 0; 390 break; 391 } 392 fs_devices = fs_devices->seed; 393 } 394 return ret; 395 } 396 397 #ifdef CONFIG_DEBUG_LOCK_ALLOC 398 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level) 399 { 400 lockdep_set_class_and_name(&eb->lock, 401 &btrfs_eb_class[level], 402 btrfs_eb_name[level]); 403 } 404 #endif 405 406 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, 407 struct extent_state *state) 408 { 409 struct extent_io_tree *tree; 410 u64 found_start; 411 int found_level; 412 unsigned long len; 413 struct extent_buffer *eb; 414 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 415 int ret = 0; 416 417 tree = &BTRFS_I(page->mapping->host)->io_tree; 418 if (page->private == EXTENT_PAGE_PRIVATE) 419 goto out; 420 if (!page->private) 421 goto out; 422 423 len = page->private >> 2; 424 WARN_ON(len == 0); 425 426 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS); 427 428 found_start = btrfs_header_bytenr(eb); 429 if (found_start != start) { 430 if (printk_ratelimit()) { 431 printk(KERN_INFO "btrfs bad tree block start " 432 "%llu %llu\n", 433 (unsigned long long)found_start, 434 (unsigned long long)eb->start); 435 } 436 ret = -EIO; 437 goto err; 438 } 439 if (eb->first_page != page) { 440 printk(KERN_INFO "btrfs bad first page %lu %lu\n", 441 eb->first_page->index, page->index); 442 WARN_ON(1); 443 ret = -EIO; 444 goto err; 445 } 446 if (check_tree_block_fsid(root, eb)) { 447 if (printk_ratelimit()) { 448 printk(KERN_INFO "btrfs bad fsid on block %llu\n", 449 (unsigned long long)eb->start); 450 } 451 ret = -EIO; 452 goto err; 453 } 454 found_level = btrfs_header_level(eb); 455 456 btrfs_set_buffer_lockdep_class(eb, found_level); 457 458 ret = csum_tree_block(root, eb, 1); 459 if (ret) 460 ret = -EIO; 461 462 end = min_t(u64, eb->len, PAGE_CACHE_SIZE); 463 end = eb->start + end - 1; 464 err: 465 free_extent_buffer(eb); 466 out: 467 return ret; 468 } 469 470 static void end_workqueue_bio(struct bio *bio, int err) 471 { 472 struct end_io_wq *end_io_wq = bio->bi_private; 473 struct btrfs_fs_info *fs_info; 474 475 fs_info = end_io_wq->info; 476 end_io_wq->error = err; 477 end_io_wq->work.func = end_workqueue_fn; 478 end_io_wq->work.flags = 0; 479 480 if (bio->bi_rw & (1 << BIO_RW)) { 481 if (end_io_wq->metadata) 482 btrfs_queue_worker(&fs_info->endio_meta_write_workers, 483 &end_io_wq->work); 484 else 485 btrfs_queue_worker(&fs_info->endio_write_workers, 486 &end_io_wq->work); 487 } else { 488 if (end_io_wq->metadata) 489 btrfs_queue_worker(&fs_info->endio_meta_workers, 490 &end_io_wq->work); 491 else 492 btrfs_queue_worker(&fs_info->endio_workers, 493 &end_io_wq->work); 494 } 495 } 496 497 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio, 498 int metadata) 499 { 500 struct end_io_wq *end_io_wq; 501 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS); 502 if (!end_io_wq) 503 return -ENOMEM; 504 505 end_io_wq->private = bio->bi_private; 506 end_io_wq->end_io = bio->bi_end_io; 507 end_io_wq->info = info; 508 end_io_wq->error = 0; 509 end_io_wq->bio = bio; 510 end_io_wq->metadata = metadata; 511 512 bio->bi_private = end_io_wq; 513 bio->bi_end_io = end_workqueue_bio; 514 return 0; 515 } 516 517 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info) 518 { 519 unsigned long limit = min_t(unsigned long, 520 info->workers.max_workers, 521 info->fs_devices->open_devices); 522 return 256 * limit; 523 } 524 525 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone) 526 { 527 return atomic_read(&info->nr_async_bios) > 528 btrfs_async_submit_limit(info); 529 } 530 531 static void run_one_async_start(struct btrfs_work *work) 532 { 533 struct btrfs_fs_info *fs_info; 534 struct async_submit_bio *async; 535 536 async = container_of(work, struct async_submit_bio, work); 537 fs_info = BTRFS_I(async->inode)->root->fs_info; 538 async->submit_bio_start(async->inode, async->rw, async->bio, 539 async->mirror_num, async->bio_flags); 540 } 541 542 static void run_one_async_done(struct btrfs_work *work) 543 { 544 struct btrfs_fs_info *fs_info; 545 struct async_submit_bio *async; 546 int limit; 547 548 async = container_of(work, struct async_submit_bio, work); 549 fs_info = BTRFS_I(async->inode)->root->fs_info; 550 551 limit = btrfs_async_submit_limit(fs_info); 552 limit = limit * 2 / 3; 553 554 atomic_dec(&fs_info->nr_async_submits); 555 556 if (atomic_read(&fs_info->nr_async_submits) < limit && 557 waitqueue_active(&fs_info->async_submit_wait)) 558 wake_up(&fs_info->async_submit_wait); 559 560 async->submit_bio_done(async->inode, async->rw, async->bio, 561 async->mirror_num, async->bio_flags); 562 } 563 564 static void run_one_async_free(struct btrfs_work *work) 565 { 566 struct async_submit_bio *async; 567 568 async = container_of(work, struct async_submit_bio, work); 569 kfree(async); 570 } 571 572 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode, 573 int rw, struct bio *bio, int mirror_num, 574 unsigned long bio_flags, 575 extent_submit_bio_hook_t *submit_bio_start, 576 extent_submit_bio_hook_t *submit_bio_done) 577 { 578 struct async_submit_bio *async; 579 580 async = kmalloc(sizeof(*async), GFP_NOFS); 581 if (!async) 582 return -ENOMEM; 583 584 async->inode = inode; 585 async->rw = rw; 586 async->bio = bio; 587 async->mirror_num = mirror_num; 588 async->submit_bio_start = submit_bio_start; 589 async->submit_bio_done = submit_bio_done; 590 591 async->work.func = run_one_async_start; 592 async->work.ordered_func = run_one_async_done; 593 async->work.ordered_free = run_one_async_free; 594 595 async->work.flags = 0; 596 async->bio_flags = bio_flags; 597 598 atomic_inc(&fs_info->nr_async_submits); 599 600 if (rw & (1 << BIO_RW_SYNCIO)) 601 btrfs_set_work_high_prio(&async->work); 602 603 btrfs_queue_worker(&fs_info->workers, &async->work); 604 605 while (atomic_read(&fs_info->async_submit_draining) && 606 atomic_read(&fs_info->nr_async_submits)) { 607 wait_event(fs_info->async_submit_wait, 608 (atomic_read(&fs_info->nr_async_submits) == 0)); 609 } 610 611 return 0; 612 } 613 614 static int btree_csum_one_bio(struct bio *bio) 615 { 616 struct bio_vec *bvec = bio->bi_io_vec; 617 int bio_index = 0; 618 struct btrfs_root *root; 619 620 WARN_ON(bio->bi_vcnt <= 0); 621 while (bio_index < bio->bi_vcnt) { 622 root = BTRFS_I(bvec->bv_page->mapping->host)->root; 623 csum_dirty_buffer(root, bvec->bv_page); 624 bio_index++; 625 bvec++; 626 } 627 return 0; 628 } 629 630 static int __btree_submit_bio_start(struct inode *inode, int rw, 631 struct bio *bio, int mirror_num, 632 unsigned long bio_flags) 633 { 634 /* 635 * when we're called for a write, we're already in the async 636 * submission context. Just jump into btrfs_map_bio 637 */ 638 btree_csum_one_bio(bio); 639 return 0; 640 } 641 642 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 643 int mirror_num, unsigned long bio_flags) 644 { 645 /* 646 * when we're called for a write, we're already in the async 647 * submission context. Just jump into btrfs_map_bio 648 */ 649 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1); 650 } 651 652 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 653 int mirror_num, unsigned long bio_flags) 654 { 655 int ret; 656 657 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info, 658 bio, 1); 659 BUG_ON(ret); 660 661 if (!(rw & (1 << BIO_RW))) { 662 /* 663 * called for a read, do the setup so that checksum validation 664 * can happen in the async kernel threads 665 */ 666 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, 667 mirror_num, 0); 668 } 669 670 /* 671 * kthread helpers are used to submit writes so that checksumming 672 * can happen in parallel across all CPUs 673 */ 674 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 675 inode, rw, bio, mirror_num, 0, 676 __btree_submit_bio_start, 677 __btree_submit_bio_done); 678 } 679 680 static int btree_writepage(struct page *page, struct writeback_control *wbc) 681 { 682 struct extent_io_tree *tree; 683 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 684 struct extent_buffer *eb; 685 int was_dirty; 686 687 tree = &BTRFS_I(page->mapping->host)->io_tree; 688 if (!(current->flags & PF_MEMALLOC)) { 689 return extent_write_full_page(tree, page, 690 btree_get_extent, wbc); 691 } 692 693 redirty_page_for_writepage(wbc, page); 694 eb = btrfs_find_tree_block(root, page_offset(page), 695 PAGE_CACHE_SIZE); 696 WARN_ON(!eb); 697 698 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); 699 if (!was_dirty) { 700 spin_lock(&root->fs_info->delalloc_lock); 701 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE; 702 spin_unlock(&root->fs_info->delalloc_lock); 703 } 704 free_extent_buffer(eb); 705 706 unlock_page(page); 707 return 0; 708 } 709 710 static int btree_writepages(struct address_space *mapping, 711 struct writeback_control *wbc) 712 { 713 struct extent_io_tree *tree; 714 tree = &BTRFS_I(mapping->host)->io_tree; 715 if (wbc->sync_mode == WB_SYNC_NONE) { 716 struct btrfs_root *root = BTRFS_I(mapping->host)->root; 717 u64 num_dirty; 718 unsigned long thresh = 32 * 1024 * 1024; 719 720 if (wbc->for_kupdate) 721 return 0; 722 723 /* this is a bit racy, but that's ok */ 724 num_dirty = root->fs_info->dirty_metadata_bytes; 725 if (num_dirty < thresh) 726 return 0; 727 } 728 return extent_writepages(tree, mapping, btree_get_extent, wbc); 729 } 730 731 static int btree_readpage(struct file *file, struct page *page) 732 { 733 struct extent_io_tree *tree; 734 tree = &BTRFS_I(page->mapping->host)->io_tree; 735 return extent_read_full_page(tree, page, btree_get_extent); 736 } 737 738 static int btree_releasepage(struct page *page, gfp_t gfp_flags) 739 { 740 struct extent_io_tree *tree; 741 struct extent_map_tree *map; 742 int ret; 743 744 if (PageWriteback(page) || PageDirty(page)) 745 return 0; 746 747 tree = &BTRFS_I(page->mapping->host)->io_tree; 748 map = &BTRFS_I(page->mapping->host)->extent_tree; 749 750 ret = try_release_extent_state(map, tree, page, gfp_flags); 751 if (!ret) 752 return 0; 753 754 ret = try_release_extent_buffer(tree, page); 755 if (ret == 1) { 756 ClearPagePrivate(page); 757 set_page_private(page, 0); 758 page_cache_release(page); 759 } 760 761 return ret; 762 } 763 764 static void btree_invalidatepage(struct page *page, unsigned long offset) 765 { 766 struct extent_io_tree *tree; 767 tree = &BTRFS_I(page->mapping->host)->io_tree; 768 extent_invalidatepage(tree, page, offset); 769 btree_releasepage(page, GFP_NOFS); 770 if (PagePrivate(page)) { 771 printk(KERN_WARNING "btrfs warning page private not zero " 772 "on page %llu\n", (unsigned long long)page_offset(page)); 773 ClearPagePrivate(page); 774 set_page_private(page, 0); 775 page_cache_release(page); 776 } 777 } 778 779 static const struct address_space_operations btree_aops = { 780 .readpage = btree_readpage, 781 .writepage = btree_writepage, 782 .writepages = btree_writepages, 783 .releasepage = btree_releasepage, 784 .invalidatepage = btree_invalidatepage, 785 .sync_page = block_sync_page, 786 }; 787 788 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, 789 u64 parent_transid) 790 { 791 struct extent_buffer *buf = NULL; 792 struct inode *btree_inode = root->fs_info->btree_inode; 793 int ret = 0; 794 795 buf = btrfs_find_create_tree_block(root, bytenr, blocksize); 796 if (!buf) 797 return 0; 798 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, 799 buf, 0, 0, btree_get_extent, 0); 800 free_extent_buffer(buf); 801 return ret; 802 } 803 804 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root, 805 u64 bytenr, u32 blocksize) 806 { 807 struct inode *btree_inode = root->fs_info->btree_inode; 808 struct extent_buffer *eb; 809 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree, 810 bytenr, blocksize, GFP_NOFS); 811 return eb; 812 } 813 814 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root, 815 u64 bytenr, u32 blocksize) 816 { 817 struct inode *btree_inode = root->fs_info->btree_inode; 818 struct extent_buffer *eb; 819 820 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree, 821 bytenr, blocksize, NULL, GFP_NOFS); 822 return eb; 823 } 824 825 826 int btrfs_write_tree_block(struct extent_buffer *buf) 827 { 828 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start, 829 buf->start + buf->len - 1); 830 } 831 832 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf) 833 { 834 return filemap_fdatawait_range(buf->first_page->mapping, 835 buf->start, buf->start + buf->len - 1); 836 } 837 838 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, 839 u32 blocksize, u64 parent_transid) 840 { 841 struct extent_buffer *buf = NULL; 842 struct inode *btree_inode = root->fs_info->btree_inode; 843 struct extent_io_tree *io_tree; 844 int ret; 845 846 io_tree = &BTRFS_I(btree_inode)->io_tree; 847 848 buf = btrfs_find_create_tree_block(root, bytenr, blocksize); 849 if (!buf) 850 return NULL; 851 852 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); 853 854 if (ret == 0) 855 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); 856 return buf; 857 858 } 859 860 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, 861 struct extent_buffer *buf) 862 { 863 struct inode *btree_inode = root->fs_info->btree_inode; 864 if (btrfs_header_generation(buf) == 865 root->fs_info->running_transaction->transid) { 866 btrfs_assert_tree_locked(buf); 867 868 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) { 869 spin_lock(&root->fs_info->delalloc_lock); 870 if (root->fs_info->dirty_metadata_bytes >= buf->len) 871 root->fs_info->dirty_metadata_bytes -= buf->len; 872 else 873 WARN_ON(1); 874 spin_unlock(&root->fs_info->delalloc_lock); 875 } 876 877 /* ugh, clear_extent_buffer_dirty needs to lock the page */ 878 btrfs_set_lock_blocking(buf); 879 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, 880 buf); 881 } 882 return 0; 883 } 884 885 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize, 886 u32 stripesize, struct btrfs_root *root, 887 struct btrfs_fs_info *fs_info, 888 u64 objectid) 889 { 890 root->node = NULL; 891 root->commit_root = NULL; 892 root->sectorsize = sectorsize; 893 root->nodesize = nodesize; 894 root->leafsize = leafsize; 895 root->stripesize = stripesize; 896 root->ref_cows = 0; 897 root->track_dirty = 0; 898 root->in_radix = 0; 899 root->clean_orphans = 0; 900 901 root->fs_info = fs_info; 902 root->objectid = objectid; 903 root->last_trans = 0; 904 root->highest_objectid = 0; 905 root->name = NULL; 906 root->in_sysfs = 0; 907 root->inode_tree = RB_ROOT; 908 909 INIT_LIST_HEAD(&root->dirty_list); 910 INIT_LIST_HEAD(&root->orphan_list); 911 INIT_LIST_HEAD(&root->root_list); 912 spin_lock_init(&root->node_lock); 913 spin_lock_init(&root->list_lock); 914 spin_lock_init(&root->inode_lock); 915 mutex_init(&root->objectid_mutex); 916 mutex_init(&root->log_mutex); 917 init_waitqueue_head(&root->log_writer_wait); 918 init_waitqueue_head(&root->log_commit_wait[0]); 919 init_waitqueue_head(&root->log_commit_wait[1]); 920 atomic_set(&root->log_commit[0], 0); 921 atomic_set(&root->log_commit[1], 0); 922 atomic_set(&root->log_writers, 0); 923 root->log_batch = 0; 924 root->log_transid = 0; 925 root->last_log_commit = 0; 926 extent_io_tree_init(&root->dirty_log_pages, 927 fs_info->btree_inode->i_mapping, GFP_NOFS); 928 929 memset(&root->root_key, 0, sizeof(root->root_key)); 930 memset(&root->root_item, 0, sizeof(root->root_item)); 931 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress)); 932 memset(&root->root_kobj, 0, sizeof(root->root_kobj)); 933 root->defrag_trans_start = fs_info->generation; 934 init_completion(&root->kobj_unregister); 935 root->defrag_running = 0; 936 root->root_key.objectid = objectid; 937 root->anon_super.s_root = NULL; 938 root->anon_super.s_dev = 0; 939 INIT_LIST_HEAD(&root->anon_super.s_list); 940 INIT_LIST_HEAD(&root->anon_super.s_instances); 941 init_rwsem(&root->anon_super.s_umount); 942 943 return 0; 944 } 945 946 static int find_and_setup_root(struct btrfs_root *tree_root, 947 struct btrfs_fs_info *fs_info, 948 u64 objectid, 949 struct btrfs_root *root) 950 { 951 int ret; 952 u32 blocksize; 953 u64 generation; 954 955 __setup_root(tree_root->nodesize, tree_root->leafsize, 956 tree_root->sectorsize, tree_root->stripesize, 957 root, fs_info, objectid); 958 ret = btrfs_find_last_root(tree_root, objectid, 959 &root->root_item, &root->root_key); 960 if (ret > 0) 961 return -ENOENT; 962 BUG_ON(ret); 963 964 generation = btrfs_root_generation(&root->root_item); 965 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); 966 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), 967 blocksize, generation); 968 BUG_ON(!root->node); 969 root->commit_root = btrfs_root_node(root); 970 return 0; 971 } 972 973 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, 974 struct btrfs_fs_info *fs_info) 975 { 976 struct extent_buffer *eb; 977 struct btrfs_root *log_root_tree = fs_info->log_root_tree; 978 u64 start = 0; 979 u64 end = 0; 980 int ret; 981 982 if (!log_root_tree) 983 return 0; 984 985 while (1) { 986 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages, 987 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW); 988 if (ret) 989 break; 990 991 clear_extent_bits(&log_root_tree->dirty_log_pages, start, end, 992 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS); 993 } 994 eb = fs_info->log_root_tree->node; 995 996 WARN_ON(btrfs_header_level(eb) != 0); 997 WARN_ON(btrfs_header_nritems(eb) != 0); 998 999 ret = btrfs_free_reserved_extent(fs_info->tree_root, 1000 eb->start, eb->len); 1001 BUG_ON(ret); 1002 1003 free_extent_buffer(eb); 1004 kfree(fs_info->log_root_tree); 1005 fs_info->log_root_tree = NULL; 1006 return 0; 1007 } 1008 1009 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans, 1010 struct btrfs_fs_info *fs_info) 1011 { 1012 struct btrfs_root *root; 1013 struct btrfs_root *tree_root = fs_info->tree_root; 1014 struct extent_buffer *leaf; 1015 1016 root = kzalloc(sizeof(*root), GFP_NOFS); 1017 if (!root) 1018 return ERR_PTR(-ENOMEM); 1019 1020 __setup_root(tree_root->nodesize, tree_root->leafsize, 1021 tree_root->sectorsize, tree_root->stripesize, 1022 root, fs_info, BTRFS_TREE_LOG_OBJECTID); 1023 1024 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID; 1025 root->root_key.type = BTRFS_ROOT_ITEM_KEY; 1026 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID; 1027 /* 1028 * log trees do not get reference counted because they go away 1029 * before a real commit is actually done. They do store pointers 1030 * to file data extents, and those reference counts still get 1031 * updated (along with back refs to the log tree). 1032 */ 1033 root->ref_cows = 0; 1034 1035 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, 1036 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0); 1037 if (IS_ERR(leaf)) { 1038 kfree(root); 1039 return ERR_CAST(leaf); 1040 } 1041 1042 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); 1043 btrfs_set_header_bytenr(leaf, leaf->start); 1044 btrfs_set_header_generation(leaf, trans->transid); 1045 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); 1046 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID); 1047 root->node = leaf; 1048 1049 write_extent_buffer(root->node, root->fs_info->fsid, 1050 (unsigned long)btrfs_header_fsid(root->node), 1051 BTRFS_FSID_SIZE); 1052 btrfs_mark_buffer_dirty(root->node); 1053 btrfs_tree_unlock(root->node); 1054 return root; 1055 } 1056 1057 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, 1058 struct btrfs_fs_info *fs_info) 1059 { 1060 struct btrfs_root *log_root; 1061 1062 log_root = alloc_log_tree(trans, fs_info); 1063 if (IS_ERR(log_root)) 1064 return PTR_ERR(log_root); 1065 WARN_ON(fs_info->log_root_tree); 1066 fs_info->log_root_tree = log_root; 1067 return 0; 1068 } 1069 1070 int btrfs_add_log_tree(struct btrfs_trans_handle *trans, 1071 struct btrfs_root *root) 1072 { 1073 struct btrfs_root *log_root; 1074 struct btrfs_inode_item *inode_item; 1075 1076 log_root = alloc_log_tree(trans, root->fs_info); 1077 if (IS_ERR(log_root)) 1078 return PTR_ERR(log_root); 1079 1080 log_root->last_trans = trans->transid; 1081 log_root->root_key.offset = root->root_key.objectid; 1082 1083 inode_item = &log_root->root_item.inode; 1084 inode_item->generation = cpu_to_le64(1); 1085 inode_item->size = cpu_to_le64(3); 1086 inode_item->nlink = cpu_to_le32(1); 1087 inode_item->nbytes = cpu_to_le64(root->leafsize); 1088 inode_item->mode = cpu_to_le32(S_IFDIR | 0755); 1089 1090 btrfs_set_root_node(&log_root->root_item, log_root->node); 1091 1092 WARN_ON(root->log_root); 1093 root->log_root = log_root; 1094 root->log_transid = 0; 1095 root->last_log_commit = 0; 1096 return 0; 1097 } 1098 1099 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, 1100 struct btrfs_key *location) 1101 { 1102 struct btrfs_root *root; 1103 struct btrfs_fs_info *fs_info = tree_root->fs_info; 1104 struct btrfs_path *path; 1105 struct extent_buffer *l; 1106 u64 generation; 1107 u32 blocksize; 1108 int ret = 0; 1109 1110 root = kzalloc(sizeof(*root), GFP_NOFS); 1111 if (!root) 1112 return ERR_PTR(-ENOMEM); 1113 if (location->offset == (u64)-1) { 1114 ret = find_and_setup_root(tree_root, fs_info, 1115 location->objectid, root); 1116 if (ret) { 1117 kfree(root); 1118 return ERR_PTR(ret); 1119 } 1120 goto out; 1121 } 1122 1123 __setup_root(tree_root->nodesize, tree_root->leafsize, 1124 tree_root->sectorsize, tree_root->stripesize, 1125 root, fs_info, location->objectid); 1126 1127 path = btrfs_alloc_path(); 1128 BUG_ON(!path); 1129 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0); 1130 if (ret == 0) { 1131 l = path->nodes[0]; 1132 read_extent_buffer(l, &root->root_item, 1133 btrfs_item_ptr_offset(l, path->slots[0]), 1134 sizeof(root->root_item)); 1135 memcpy(&root->root_key, location, sizeof(*location)); 1136 } 1137 btrfs_free_path(path); 1138 if (ret) { 1139 if (ret > 0) 1140 ret = -ENOENT; 1141 return ERR_PTR(ret); 1142 } 1143 1144 generation = btrfs_root_generation(&root->root_item); 1145 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); 1146 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), 1147 blocksize, generation); 1148 root->commit_root = btrfs_root_node(root); 1149 BUG_ON(!root->node); 1150 out: 1151 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) 1152 root->ref_cows = 1; 1153 1154 return root; 1155 } 1156 1157 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, 1158 u64 root_objectid) 1159 { 1160 struct btrfs_root *root; 1161 1162 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID) 1163 return fs_info->tree_root; 1164 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) 1165 return fs_info->extent_root; 1166 1167 root = radix_tree_lookup(&fs_info->fs_roots_radix, 1168 (unsigned long)root_objectid); 1169 return root; 1170 } 1171 1172 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, 1173 struct btrfs_key *location) 1174 { 1175 struct btrfs_root *root; 1176 int ret; 1177 1178 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) 1179 return fs_info->tree_root; 1180 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID) 1181 return fs_info->extent_root; 1182 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) 1183 return fs_info->chunk_root; 1184 if (location->objectid == BTRFS_DEV_TREE_OBJECTID) 1185 return fs_info->dev_root; 1186 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) 1187 return fs_info->csum_root; 1188 again: 1189 spin_lock(&fs_info->fs_roots_radix_lock); 1190 root = radix_tree_lookup(&fs_info->fs_roots_radix, 1191 (unsigned long)location->objectid); 1192 spin_unlock(&fs_info->fs_roots_radix_lock); 1193 if (root) 1194 return root; 1195 1196 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid); 1197 if (ret == 0) 1198 ret = -ENOENT; 1199 if (ret < 0) 1200 return ERR_PTR(ret); 1201 1202 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location); 1203 if (IS_ERR(root)) 1204 return root; 1205 1206 WARN_ON(btrfs_root_refs(&root->root_item) == 0); 1207 set_anon_super(&root->anon_super, NULL); 1208 1209 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); 1210 if (ret) 1211 goto fail; 1212 1213 spin_lock(&fs_info->fs_roots_radix_lock); 1214 ret = radix_tree_insert(&fs_info->fs_roots_radix, 1215 (unsigned long)root->root_key.objectid, 1216 root); 1217 if (ret == 0) { 1218 root->in_radix = 1; 1219 root->clean_orphans = 1; 1220 } 1221 spin_unlock(&fs_info->fs_roots_radix_lock); 1222 radix_tree_preload_end(); 1223 if (ret) { 1224 if (ret == -EEXIST) { 1225 free_fs_root(root); 1226 goto again; 1227 } 1228 goto fail; 1229 } 1230 1231 ret = btrfs_find_dead_roots(fs_info->tree_root, 1232 root->root_key.objectid); 1233 WARN_ON(ret); 1234 return root; 1235 fail: 1236 free_fs_root(root); 1237 return ERR_PTR(ret); 1238 } 1239 1240 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, 1241 struct btrfs_key *location, 1242 const char *name, int namelen) 1243 { 1244 return btrfs_read_fs_root_no_name(fs_info, location); 1245 #if 0 1246 struct btrfs_root *root; 1247 int ret; 1248 1249 root = btrfs_read_fs_root_no_name(fs_info, location); 1250 if (!root) 1251 return NULL; 1252 1253 if (root->in_sysfs) 1254 return root; 1255 1256 ret = btrfs_set_root_name(root, name, namelen); 1257 if (ret) { 1258 free_extent_buffer(root->node); 1259 kfree(root); 1260 return ERR_PTR(ret); 1261 } 1262 1263 ret = btrfs_sysfs_add_root(root); 1264 if (ret) { 1265 free_extent_buffer(root->node); 1266 kfree(root->name); 1267 kfree(root); 1268 return ERR_PTR(ret); 1269 } 1270 root->in_sysfs = 1; 1271 return root; 1272 #endif 1273 } 1274 1275 static int btrfs_congested_fn(void *congested_data, int bdi_bits) 1276 { 1277 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data; 1278 int ret = 0; 1279 struct btrfs_device *device; 1280 struct backing_dev_info *bdi; 1281 1282 list_for_each_entry(device, &info->fs_devices->devices, dev_list) { 1283 if (!device->bdev) 1284 continue; 1285 bdi = blk_get_backing_dev_info(device->bdev); 1286 if (bdi && bdi_congested(bdi, bdi_bits)) { 1287 ret = 1; 1288 break; 1289 } 1290 } 1291 return ret; 1292 } 1293 1294 /* 1295 * this unplugs every device on the box, and it is only used when page 1296 * is null 1297 */ 1298 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page) 1299 { 1300 struct btrfs_device *device; 1301 struct btrfs_fs_info *info; 1302 1303 info = (struct btrfs_fs_info *)bdi->unplug_io_data; 1304 list_for_each_entry(device, &info->fs_devices->devices, dev_list) { 1305 if (!device->bdev) 1306 continue; 1307 1308 bdi = blk_get_backing_dev_info(device->bdev); 1309 if (bdi->unplug_io_fn) 1310 bdi->unplug_io_fn(bdi, page); 1311 } 1312 } 1313 1314 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) 1315 { 1316 struct inode *inode; 1317 struct extent_map_tree *em_tree; 1318 struct extent_map *em; 1319 struct address_space *mapping; 1320 u64 offset; 1321 1322 /* the generic O_DIRECT read code does this */ 1323 if (1 || !page) { 1324 __unplug_io_fn(bdi, page); 1325 return; 1326 } 1327 1328 /* 1329 * page->mapping may change at any time. Get a consistent copy 1330 * and use that for everything below 1331 */ 1332 smp_mb(); 1333 mapping = page->mapping; 1334 if (!mapping) 1335 return; 1336 1337 inode = mapping->host; 1338 1339 /* 1340 * don't do the expensive searching for a small number of 1341 * devices 1342 */ 1343 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) { 1344 __unplug_io_fn(bdi, page); 1345 return; 1346 } 1347 1348 offset = page_offset(page); 1349 1350 em_tree = &BTRFS_I(inode)->extent_tree; 1351 read_lock(&em_tree->lock); 1352 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE); 1353 read_unlock(&em_tree->lock); 1354 if (!em) { 1355 __unplug_io_fn(bdi, page); 1356 return; 1357 } 1358 1359 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 1360 free_extent_map(em); 1361 __unplug_io_fn(bdi, page); 1362 return; 1363 } 1364 offset = offset - em->start; 1365 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree, 1366 em->block_start + offset, page); 1367 free_extent_map(em); 1368 } 1369 1370 /* 1371 * If this fails, caller must call bdi_destroy() to get rid of the 1372 * bdi again. 1373 */ 1374 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi) 1375 { 1376 int err; 1377 1378 bdi->name = "btrfs"; 1379 bdi->capabilities = BDI_CAP_MAP_COPY; 1380 err = bdi_init(bdi); 1381 if (err) 1382 return err; 1383 1384 err = bdi_register(bdi, NULL, "btrfs-%d", 1385 atomic_inc_return(&btrfs_bdi_num)); 1386 if (err) { 1387 bdi_destroy(bdi); 1388 return err; 1389 } 1390 1391 bdi->ra_pages = default_backing_dev_info.ra_pages; 1392 bdi->unplug_io_fn = btrfs_unplug_io_fn; 1393 bdi->unplug_io_data = info; 1394 bdi->congested_fn = btrfs_congested_fn; 1395 bdi->congested_data = info; 1396 return 0; 1397 } 1398 1399 static int bio_ready_for_csum(struct bio *bio) 1400 { 1401 u64 length = 0; 1402 u64 buf_len = 0; 1403 u64 start = 0; 1404 struct page *page; 1405 struct extent_io_tree *io_tree = NULL; 1406 struct btrfs_fs_info *info = NULL; 1407 struct bio_vec *bvec; 1408 int i; 1409 int ret; 1410 1411 bio_for_each_segment(bvec, bio, i) { 1412 page = bvec->bv_page; 1413 if (page->private == EXTENT_PAGE_PRIVATE) { 1414 length += bvec->bv_len; 1415 continue; 1416 } 1417 if (!page->private) { 1418 length += bvec->bv_len; 1419 continue; 1420 } 1421 length = bvec->bv_len; 1422 buf_len = page->private >> 2; 1423 start = page_offset(page) + bvec->bv_offset; 1424 io_tree = &BTRFS_I(page->mapping->host)->io_tree; 1425 info = BTRFS_I(page->mapping->host)->root->fs_info; 1426 } 1427 /* are we fully contained in this bio? */ 1428 if (buf_len <= length) 1429 return 1; 1430 1431 ret = extent_range_uptodate(io_tree, start + length, 1432 start + buf_len - 1); 1433 return ret; 1434 } 1435 1436 /* 1437 * called by the kthread helper functions to finally call the bio end_io 1438 * functions. This is where read checksum verification actually happens 1439 */ 1440 static void end_workqueue_fn(struct btrfs_work *work) 1441 { 1442 struct bio *bio; 1443 struct end_io_wq *end_io_wq; 1444 struct btrfs_fs_info *fs_info; 1445 int error; 1446 1447 end_io_wq = container_of(work, struct end_io_wq, work); 1448 bio = end_io_wq->bio; 1449 fs_info = end_io_wq->info; 1450 1451 /* metadata bio reads are special because the whole tree block must 1452 * be checksummed at once. This makes sure the entire block is in 1453 * ram and up to date before trying to verify things. For 1454 * blocksize <= pagesize, it is basically a noop 1455 */ 1456 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata && 1457 !bio_ready_for_csum(bio)) { 1458 btrfs_queue_worker(&fs_info->endio_meta_workers, 1459 &end_io_wq->work); 1460 return; 1461 } 1462 error = end_io_wq->error; 1463 bio->bi_private = end_io_wq->private; 1464 bio->bi_end_io = end_io_wq->end_io; 1465 kfree(end_io_wq); 1466 bio_endio(bio, error); 1467 } 1468 1469 static int cleaner_kthread(void *arg) 1470 { 1471 struct btrfs_root *root = arg; 1472 1473 do { 1474 smp_mb(); 1475 if (root->fs_info->closing) 1476 break; 1477 1478 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); 1479 1480 if (!(root->fs_info->sb->s_flags & MS_RDONLY) && 1481 mutex_trylock(&root->fs_info->cleaner_mutex)) { 1482 btrfs_run_delayed_iputs(root); 1483 btrfs_clean_old_snapshots(root); 1484 mutex_unlock(&root->fs_info->cleaner_mutex); 1485 } 1486 1487 if (freezing(current)) { 1488 refrigerator(); 1489 } else { 1490 smp_mb(); 1491 if (root->fs_info->closing) 1492 break; 1493 set_current_state(TASK_INTERRUPTIBLE); 1494 schedule(); 1495 __set_current_state(TASK_RUNNING); 1496 } 1497 } while (!kthread_should_stop()); 1498 return 0; 1499 } 1500 1501 static int transaction_kthread(void *arg) 1502 { 1503 struct btrfs_root *root = arg; 1504 struct btrfs_trans_handle *trans; 1505 struct btrfs_transaction *cur; 1506 unsigned long now; 1507 unsigned long delay; 1508 int ret; 1509 1510 do { 1511 smp_mb(); 1512 if (root->fs_info->closing) 1513 break; 1514 1515 delay = HZ * 30; 1516 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); 1517 mutex_lock(&root->fs_info->transaction_kthread_mutex); 1518 1519 mutex_lock(&root->fs_info->trans_mutex); 1520 cur = root->fs_info->running_transaction; 1521 if (!cur) { 1522 mutex_unlock(&root->fs_info->trans_mutex); 1523 goto sleep; 1524 } 1525 1526 now = get_seconds(); 1527 if (now < cur->start_time || now - cur->start_time < 30) { 1528 mutex_unlock(&root->fs_info->trans_mutex); 1529 delay = HZ * 5; 1530 goto sleep; 1531 } 1532 mutex_unlock(&root->fs_info->trans_mutex); 1533 trans = btrfs_start_transaction(root, 1); 1534 ret = btrfs_commit_transaction(trans, root); 1535 1536 sleep: 1537 wake_up_process(root->fs_info->cleaner_kthread); 1538 mutex_unlock(&root->fs_info->transaction_kthread_mutex); 1539 1540 if (freezing(current)) { 1541 refrigerator(); 1542 } else { 1543 if (root->fs_info->closing) 1544 break; 1545 set_current_state(TASK_INTERRUPTIBLE); 1546 schedule_timeout(delay); 1547 __set_current_state(TASK_RUNNING); 1548 } 1549 } while (!kthread_should_stop()); 1550 return 0; 1551 } 1552 1553 struct btrfs_root *open_ctree(struct super_block *sb, 1554 struct btrfs_fs_devices *fs_devices, 1555 char *options) 1556 { 1557 u32 sectorsize; 1558 u32 nodesize; 1559 u32 leafsize; 1560 u32 blocksize; 1561 u32 stripesize; 1562 u64 generation; 1563 u64 features; 1564 struct btrfs_key location; 1565 struct buffer_head *bh; 1566 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root), 1567 GFP_NOFS); 1568 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root), 1569 GFP_NOFS); 1570 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root), 1571 GFP_NOFS); 1572 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info), 1573 GFP_NOFS); 1574 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root), 1575 GFP_NOFS); 1576 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root), 1577 GFP_NOFS); 1578 struct btrfs_root *log_tree_root; 1579 1580 int ret; 1581 int err = -EINVAL; 1582 1583 struct btrfs_super_block *disk_super; 1584 1585 if (!extent_root || !tree_root || !fs_info || 1586 !chunk_root || !dev_root || !csum_root) { 1587 err = -ENOMEM; 1588 goto fail; 1589 } 1590 1591 ret = init_srcu_struct(&fs_info->subvol_srcu); 1592 if (ret) { 1593 err = ret; 1594 goto fail; 1595 } 1596 1597 ret = setup_bdi(fs_info, &fs_info->bdi); 1598 if (ret) { 1599 err = ret; 1600 goto fail_srcu; 1601 } 1602 1603 fs_info->btree_inode = new_inode(sb); 1604 if (!fs_info->btree_inode) { 1605 err = -ENOMEM; 1606 goto fail_bdi; 1607 } 1608 1609 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC); 1610 INIT_LIST_HEAD(&fs_info->trans_list); 1611 INIT_LIST_HEAD(&fs_info->dead_roots); 1612 INIT_LIST_HEAD(&fs_info->delayed_iputs); 1613 INIT_LIST_HEAD(&fs_info->hashers); 1614 INIT_LIST_HEAD(&fs_info->delalloc_inodes); 1615 INIT_LIST_HEAD(&fs_info->ordered_operations); 1616 INIT_LIST_HEAD(&fs_info->caching_block_groups); 1617 spin_lock_init(&fs_info->delalloc_lock); 1618 spin_lock_init(&fs_info->new_trans_lock); 1619 spin_lock_init(&fs_info->ref_cache_lock); 1620 spin_lock_init(&fs_info->fs_roots_radix_lock); 1621 spin_lock_init(&fs_info->delayed_iput_lock); 1622 1623 init_completion(&fs_info->kobj_unregister); 1624 fs_info->tree_root = tree_root; 1625 fs_info->extent_root = extent_root; 1626 fs_info->csum_root = csum_root; 1627 fs_info->chunk_root = chunk_root; 1628 fs_info->dev_root = dev_root; 1629 fs_info->fs_devices = fs_devices; 1630 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); 1631 INIT_LIST_HEAD(&fs_info->space_info); 1632 btrfs_mapping_init(&fs_info->mapping_tree); 1633 atomic_set(&fs_info->nr_async_submits, 0); 1634 atomic_set(&fs_info->async_delalloc_pages, 0); 1635 atomic_set(&fs_info->async_submit_draining, 0); 1636 atomic_set(&fs_info->nr_async_bios, 0); 1637 fs_info->sb = sb; 1638 fs_info->max_inline = 8192 * 1024; 1639 fs_info->metadata_ratio = 0; 1640 1641 fs_info->thread_pool_size = min_t(unsigned long, 1642 num_online_cpus() + 2, 8); 1643 1644 INIT_LIST_HEAD(&fs_info->ordered_extents); 1645 spin_lock_init(&fs_info->ordered_extent_lock); 1646 1647 sb->s_blocksize = 4096; 1648 sb->s_blocksize_bits = blksize_bits(4096); 1649 sb->s_bdi = &fs_info->bdi; 1650 1651 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID; 1652 fs_info->btree_inode->i_nlink = 1; 1653 /* 1654 * we set the i_size on the btree inode to the max possible int. 1655 * the real end of the address space is determined by all of 1656 * the devices in the system 1657 */ 1658 fs_info->btree_inode->i_size = OFFSET_MAX; 1659 fs_info->btree_inode->i_mapping->a_ops = &btree_aops; 1660 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi; 1661 1662 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node); 1663 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree, 1664 fs_info->btree_inode->i_mapping, 1665 GFP_NOFS); 1666 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree, 1667 GFP_NOFS); 1668 1669 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops; 1670 1671 BTRFS_I(fs_info->btree_inode)->root = tree_root; 1672 memset(&BTRFS_I(fs_info->btree_inode)->location, 0, 1673 sizeof(struct btrfs_key)); 1674 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1; 1675 insert_inode_hash(fs_info->btree_inode); 1676 1677 spin_lock_init(&fs_info->block_group_cache_lock); 1678 fs_info->block_group_cache_tree = RB_ROOT; 1679 1680 extent_io_tree_init(&fs_info->freed_extents[0], 1681 fs_info->btree_inode->i_mapping, GFP_NOFS); 1682 extent_io_tree_init(&fs_info->freed_extents[1], 1683 fs_info->btree_inode->i_mapping, GFP_NOFS); 1684 fs_info->pinned_extents = &fs_info->freed_extents[0]; 1685 fs_info->do_barriers = 1; 1686 1687 1688 mutex_init(&fs_info->trans_mutex); 1689 mutex_init(&fs_info->ordered_operations_mutex); 1690 mutex_init(&fs_info->tree_log_mutex); 1691 mutex_init(&fs_info->chunk_mutex); 1692 mutex_init(&fs_info->transaction_kthread_mutex); 1693 mutex_init(&fs_info->cleaner_mutex); 1694 mutex_init(&fs_info->volume_mutex); 1695 init_rwsem(&fs_info->extent_commit_sem); 1696 init_rwsem(&fs_info->cleanup_work_sem); 1697 init_rwsem(&fs_info->subvol_sem); 1698 1699 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster); 1700 btrfs_init_free_cluster(&fs_info->data_alloc_cluster); 1701 1702 init_waitqueue_head(&fs_info->transaction_throttle); 1703 init_waitqueue_head(&fs_info->transaction_wait); 1704 init_waitqueue_head(&fs_info->async_submit_wait); 1705 1706 __setup_root(4096, 4096, 4096, 4096, tree_root, 1707 fs_info, BTRFS_ROOT_TREE_OBJECTID); 1708 1709 1710 bh = btrfs_read_dev_super(fs_devices->latest_bdev); 1711 if (!bh) 1712 goto fail_iput; 1713 1714 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy)); 1715 memcpy(&fs_info->super_for_commit, &fs_info->super_copy, 1716 sizeof(fs_info->super_for_commit)); 1717 brelse(bh); 1718 1719 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE); 1720 1721 disk_super = &fs_info->super_copy; 1722 if (!btrfs_super_root(disk_super)) 1723 goto fail_iput; 1724 1725 ret = btrfs_parse_options(tree_root, options); 1726 if (ret) { 1727 err = ret; 1728 goto fail_iput; 1729 } 1730 1731 features = btrfs_super_incompat_flags(disk_super) & 1732 ~BTRFS_FEATURE_INCOMPAT_SUPP; 1733 if (features) { 1734 printk(KERN_ERR "BTRFS: couldn't mount because of " 1735 "unsupported optional features (%Lx).\n", 1736 (unsigned long long)features); 1737 err = -EINVAL; 1738 goto fail_iput; 1739 } 1740 1741 features = btrfs_super_incompat_flags(disk_super); 1742 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) { 1743 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; 1744 btrfs_set_super_incompat_flags(disk_super, features); 1745 } 1746 1747 features = btrfs_super_compat_ro_flags(disk_super) & 1748 ~BTRFS_FEATURE_COMPAT_RO_SUPP; 1749 if (!(sb->s_flags & MS_RDONLY) && features) { 1750 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of " 1751 "unsupported option features (%Lx).\n", 1752 (unsigned long long)features); 1753 err = -EINVAL; 1754 goto fail_iput; 1755 } 1756 1757 btrfs_init_workers(&fs_info->generic_worker, 1758 "genwork", 1, NULL); 1759 1760 btrfs_init_workers(&fs_info->workers, "worker", 1761 fs_info->thread_pool_size, 1762 &fs_info->generic_worker); 1763 1764 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc", 1765 fs_info->thread_pool_size, 1766 &fs_info->generic_worker); 1767 1768 btrfs_init_workers(&fs_info->submit_workers, "submit", 1769 min_t(u64, fs_devices->num_devices, 1770 fs_info->thread_pool_size), 1771 &fs_info->generic_worker); 1772 btrfs_init_workers(&fs_info->enospc_workers, "enospc", 1773 fs_info->thread_pool_size, 1774 &fs_info->generic_worker); 1775 1776 /* a higher idle thresh on the submit workers makes it much more 1777 * likely that bios will be send down in a sane order to the 1778 * devices 1779 */ 1780 fs_info->submit_workers.idle_thresh = 64; 1781 1782 fs_info->workers.idle_thresh = 16; 1783 fs_info->workers.ordered = 1; 1784 1785 fs_info->delalloc_workers.idle_thresh = 2; 1786 fs_info->delalloc_workers.ordered = 1; 1787 1788 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1, 1789 &fs_info->generic_worker); 1790 btrfs_init_workers(&fs_info->endio_workers, "endio", 1791 fs_info->thread_pool_size, 1792 &fs_info->generic_worker); 1793 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta", 1794 fs_info->thread_pool_size, 1795 &fs_info->generic_worker); 1796 btrfs_init_workers(&fs_info->endio_meta_write_workers, 1797 "endio-meta-write", fs_info->thread_pool_size, 1798 &fs_info->generic_worker); 1799 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write", 1800 fs_info->thread_pool_size, 1801 &fs_info->generic_worker); 1802 1803 /* 1804 * endios are largely parallel and should have a very 1805 * low idle thresh 1806 */ 1807 fs_info->endio_workers.idle_thresh = 4; 1808 fs_info->endio_meta_workers.idle_thresh = 4; 1809 1810 fs_info->endio_write_workers.idle_thresh = 2; 1811 fs_info->endio_meta_write_workers.idle_thresh = 2; 1812 1813 btrfs_start_workers(&fs_info->workers, 1); 1814 btrfs_start_workers(&fs_info->generic_worker, 1); 1815 btrfs_start_workers(&fs_info->submit_workers, 1); 1816 btrfs_start_workers(&fs_info->delalloc_workers, 1); 1817 btrfs_start_workers(&fs_info->fixup_workers, 1); 1818 btrfs_start_workers(&fs_info->endio_workers, 1); 1819 btrfs_start_workers(&fs_info->endio_meta_workers, 1); 1820 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1); 1821 btrfs_start_workers(&fs_info->endio_write_workers, 1); 1822 btrfs_start_workers(&fs_info->enospc_workers, 1); 1823 1824 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super); 1825 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages, 1826 4 * 1024 * 1024 / PAGE_CACHE_SIZE); 1827 1828 nodesize = btrfs_super_nodesize(disk_super); 1829 leafsize = btrfs_super_leafsize(disk_super); 1830 sectorsize = btrfs_super_sectorsize(disk_super); 1831 stripesize = btrfs_super_stripesize(disk_super); 1832 tree_root->nodesize = nodesize; 1833 tree_root->leafsize = leafsize; 1834 tree_root->sectorsize = sectorsize; 1835 tree_root->stripesize = stripesize; 1836 1837 sb->s_blocksize = sectorsize; 1838 sb->s_blocksize_bits = blksize_bits(sectorsize); 1839 1840 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, 1841 sizeof(disk_super->magic))) { 1842 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id); 1843 goto fail_sb_buffer; 1844 } 1845 1846 mutex_lock(&fs_info->chunk_mutex); 1847 ret = btrfs_read_sys_array(tree_root); 1848 mutex_unlock(&fs_info->chunk_mutex); 1849 if (ret) { 1850 printk(KERN_WARNING "btrfs: failed to read the system " 1851 "array on %s\n", sb->s_id); 1852 goto fail_sb_buffer; 1853 } 1854 1855 blocksize = btrfs_level_size(tree_root, 1856 btrfs_super_chunk_root_level(disk_super)); 1857 generation = btrfs_super_chunk_root_generation(disk_super); 1858 1859 __setup_root(nodesize, leafsize, sectorsize, stripesize, 1860 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID); 1861 1862 chunk_root->node = read_tree_block(chunk_root, 1863 btrfs_super_chunk_root(disk_super), 1864 blocksize, generation); 1865 BUG_ON(!chunk_root->node); 1866 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) { 1867 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n", 1868 sb->s_id); 1869 goto fail_chunk_root; 1870 } 1871 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node); 1872 chunk_root->commit_root = btrfs_root_node(chunk_root); 1873 1874 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid, 1875 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node), 1876 BTRFS_UUID_SIZE); 1877 1878 mutex_lock(&fs_info->chunk_mutex); 1879 ret = btrfs_read_chunk_tree(chunk_root); 1880 mutex_unlock(&fs_info->chunk_mutex); 1881 if (ret) { 1882 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n", 1883 sb->s_id); 1884 goto fail_chunk_root; 1885 } 1886 1887 btrfs_close_extra_devices(fs_devices); 1888 1889 blocksize = btrfs_level_size(tree_root, 1890 btrfs_super_root_level(disk_super)); 1891 generation = btrfs_super_generation(disk_super); 1892 1893 tree_root->node = read_tree_block(tree_root, 1894 btrfs_super_root(disk_super), 1895 blocksize, generation); 1896 if (!tree_root->node) 1897 goto fail_chunk_root; 1898 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) { 1899 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n", 1900 sb->s_id); 1901 goto fail_tree_root; 1902 } 1903 btrfs_set_root_node(&tree_root->root_item, tree_root->node); 1904 tree_root->commit_root = btrfs_root_node(tree_root); 1905 1906 ret = find_and_setup_root(tree_root, fs_info, 1907 BTRFS_EXTENT_TREE_OBJECTID, extent_root); 1908 if (ret) 1909 goto fail_tree_root; 1910 extent_root->track_dirty = 1; 1911 1912 ret = find_and_setup_root(tree_root, fs_info, 1913 BTRFS_DEV_TREE_OBJECTID, dev_root); 1914 if (ret) 1915 goto fail_extent_root; 1916 dev_root->track_dirty = 1; 1917 1918 ret = find_and_setup_root(tree_root, fs_info, 1919 BTRFS_CSUM_TREE_OBJECTID, csum_root); 1920 if (ret) 1921 goto fail_dev_root; 1922 1923 csum_root->track_dirty = 1; 1924 1925 ret = btrfs_read_block_groups(extent_root); 1926 if (ret) { 1927 printk(KERN_ERR "Failed to read block groups: %d\n", ret); 1928 goto fail_block_groups; 1929 } 1930 1931 fs_info->generation = generation; 1932 fs_info->last_trans_committed = generation; 1933 fs_info->data_alloc_profile = (u64)-1; 1934 fs_info->metadata_alloc_profile = (u64)-1; 1935 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile; 1936 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root, 1937 "btrfs-cleaner"); 1938 if (IS_ERR(fs_info->cleaner_kthread)) 1939 goto fail_block_groups; 1940 1941 fs_info->transaction_kthread = kthread_run(transaction_kthread, 1942 tree_root, 1943 "btrfs-transaction"); 1944 if (IS_ERR(fs_info->transaction_kthread)) 1945 goto fail_cleaner; 1946 1947 if (!btrfs_test_opt(tree_root, SSD) && 1948 !btrfs_test_opt(tree_root, NOSSD) && 1949 !fs_info->fs_devices->rotating) { 1950 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD " 1951 "mode\n"); 1952 btrfs_set_opt(fs_info->mount_opt, SSD); 1953 } 1954 1955 if (btrfs_super_log_root(disk_super) != 0) { 1956 u64 bytenr = btrfs_super_log_root(disk_super); 1957 1958 if (fs_devices->rw_devices == 0) { 1959 printk(KERN_WARNING "Btrfs log replay required " 1960 "on RO media\n"); 1961 err = -EIO; 1962 goto fail_trans_kthread; 1963 } 1964 blocksize = 1965 btrfs_level_size(tree_root, 1966 btrfs_super_log_root_level(disk_super)); 1967 1968 log_tree_root = kzalloc(sizeof(struct btrfs_root), 1969 GFP_NOFS); 1970 1971 __setup_root(nodesize, leafsize, sectorsize, stripesize, 1972 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID); 1973 1974 log_tree_root->node = read_tree_block(tree_root, bytenr, 1975 blocksize, 1976 generation + 1); 1977 ret = btrfs_recover_log_trees(log_tree_root); 1978 BUG_ON(ret); 1979 1980 if (sb->s_flags & MS_RDONLY) { 1981 ret = btrfs_commit_super(tree_root); 1982 BUG_ON(ret); 1983 } 1984 } 1985 1986 ret = btrfs_find_orphan_roots(tree_root); 1987 BUG_ON(ret); 1988 1989 if (!(sb->s_flags & MS_RDONLY)) { 1990 ret = btrfs_recover_relocation(tree_root); 1991 if (ret < 0) { 1992 printk(KERN_WARNING 1993 "btrfs: failed to recover relocation\n"); 1994 err = -EINVAL; 1995 goto fail_trans_kthread; 1996 } 1997 } 1998 1999 location.objectid = BTRFS_FS_TREE_OBJECTID; 2000 location.type = BTRFS_ROOT_ITEM_KEY; 2001 location.offset = (u64)-1; 2002 2003 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location); 2004 if (!fs_info->fs_root) 2005 goto fail_trans_kthread; 2006 2007 if (!(sb->s_flags & MS_RDONLY)) { 2008 down_read(&fs_info->cleanup_work_sem); 2009 btrfs_orphan_cleanup(fs_info->fs_root); 2010 up_read(&fs_info->cleanup_work_sem); 2011 } 2012 2013 return tree_root; 2014 2015 fail_trans_kthread: 2016 kthread_stop(fs_info->transaction_kthread); 2017 fail_cleaner: 2018 kthread_stop(fs_info->cleaner_kthread); 2019 2020 /* 2021 * make sure we're done with the btree inode before we stop our 2022 * kthreads 2023 */ 2024 filemap_write_and_wait(fs_info->btree_inode->i_mapping); 2025 invalidate_inode_pages2(fs_info->btree_inode->i_mapping); 2026 2027 fail_block_groups: 2028 btrfs_free_block_groups(fs_info); 2029 free_extent_buffer(csum_root->node); 2030 free_extent_buffer(csum_root->commit_root); 2031 fail_dev_root: 2032 free_extent_buffer(dev_root->node); 2033 free_extent_buffer(dev_root->commit_root); 2034 fail_extent_root: 2035 free_extent_buffer(extent_root->node); 2036 free_extent_buffer(extent_root->commit_root); 2037 fail_tree_root: 2038 free_extent_buffer(tree_root->node); 2039 free_extent_buffer(tree_root->commit_root); 2040 fail_chunk_root: 2041 free_extent_buffer(chunk_root->node); 2042 free_extent_buffer(chunk_root->commit_root); 2043 fail_sb_buffer: 2044 btrfs_stop_workers(&fs_info->generic_worker); 2045 btrfs_stop_workers(&fs_info->fixup_workers); 2046 btrfs_stop_workers(&fs_info->delalloc_workers); 2047 btrfs_stop_workers(&fs_info->workers); 2048 btrfs_stop_workers(&fs_info->endio_workers); 2049 btrfs_stop_workers(&fs_info->endio_meta_workers); 2050 btrfs_stop_workers(&fs_info->endio_meta_write_workers); 2051 btrfs_stop_workers(&fs_info->endio_write_workers); 2052 btrfs_stop_workers(&fs_info->submit_workers); 2053 btrfs_stop_workers(&fs_info->enospc_workers); 2054 fail_iput: 2055 invalidate_inode_pages2(fs_info->btree_inode->i_mapping); 2056 iput(fs_info->btree_inode); 2057 2058 btrfs_close_devices(fs_info->fs_devices); 2059 btrfs_mapping_tree_free(&fs_info->mapping_tree); 2060 fail_bdi: 2061 bdi_destroy(&fs_info->bdi); 2062 fail_srcu: 2063 cleanup_srcu_struct(&fs_info->subvol_srcu); 2064 fail: 2065 kfree(extent_root); 2066 kfree(tree_root); 2067 kfree(fs_info); 2068 kfree(chunk_root); 2069 kfree(dev_root); 2070 kfree(csum_root); 2071 return ERR_PTR(err); 2072 } 2073 2074 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) 2075 { 2076 char b[BDEVNAME_SIZE]; 2077 2078 if (uptodate) { 2079 set_buffer_uptodate(bh); 2080 } else { 2081 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) { 2082 printk(KERN_WARNING "lost page write due to " 2083 "I/O error on %s\n", 2084 bdevname(bh->b_bdev, b)); 2085 } 2086 /* note, we dont' set_buffer_write_io_error because we have 2087 * our own ways of dealing with the IO errors 2088 */ 2089 clear_buffer_uptodate(bh); 2090 } 2091 unlock_buffer(bh); 2092 put_bh(bh); 2093 } 2094 2095 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev) 2096 { 2097 struct buffer_head *bh; 2098 struct buffer_head *latest = NULL; 2099 struct btrfs_super_block *super; 2100 int i; 2101 u64 transid = 0; 2102 u64 bytenr; 2103 2104 /* we would like to check all the supers, but that would make 2105 * a btrfs mount succeed after a mkfs from a different FS. 2106 * So, we need to add a special mount option to scan for 2107 * later supers, using BTRFS_SUPER_MIRROR_MAX instead 2108 */ 2109 for (i = 0; i < 1; i++) { 2110 bytenr = btrfs_sb_offset(i); 2111 if (bytenr + 4096 >= i_size_read(bdev->bd_inode)) 2112 break; 2113 bh = __bread(bdev, bytenr / 4096, 4096); 2114 if (!bh) 2115 continue; 2116 2117 super = (struct btrfs_super_block *)bh->b_data; 2118 if (btrfs_super_bytenr(super) != bytenr || 2119 strncmp((char *)(&super->magic), BTRFS_MAGIC, 2120 sizeof(super->magic))) { 2121 brelse(bh); 2122 continue; 2123 } 2124 2125 if (!latest || btrfs_super_generation(super) > transid) { 2126 brelse(latest); 2127 latest = bh; 2128 transid = btrfs_super_generation(super); 2129 } else { 2130 brelse(bh); 2131 } 2132 } 2133 return latest; 2134 } 2135 2136 /* 2137 * this should be called twice, once with wait == 0 and 2138 * once with wait == 1. When wait == 0 is done, all the buffer heads 2139 * we write are pinned. 2140 * 2141 * They are released when wait == 1 is done. 2142 * max_mirrors must be the same for both runs, and it indicates how 2143 * many supers on this one device should be written. 2144 * 2145 * max_mirrors == 0 means to write them all. 2146 */ 2147 static int write_dev_supers(struct btrfs_device *device, 2148 struct btrfs_super_block *sb, 2149 int do_barriers, int wait, int max_mirrors) 2150 { 2151 struct buffer_head *bh; 2152 int i; 2153 int ret; 2154 int errors = 0; 2155 u32 crc; 2156 u64 bytenr; 2157 int last_barrier = 0; 2158 2159 if (max_mirrors == 0) 2160 max_mirrors = BTRFS_SUPER_MIRROR_MAX; 2161 2162 /* make sure only the last submit_bh does a barrier */ 2163 if (do_barriers) { 2164 for (i = 0; i < max_mirrors; i++) { 2165 bytenr = btrfs_sb_offset(i); 2166 if (bytenr + BTRFS_SUPER_INFO_SIZE >= 2167 device->total_bytes) 2168 break; 2169 last_barrier = i; 2170 } 2171 } 2172 2173 for (i = 0; i < max_mirrors; i++) { 2174 bytenr = btrfs_sb_offset(i); 2175 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes) 2176 break; 2177 2178 if (wait) { 2179 bh = __find_get_block(device->bdev, bytenr / 4096, 2180 BTRFS_SUPER_INFO_SIZE); 2181 BUG_ON(!bh); 2182 wait_on_buffer(bh); 2183 if (!buffer_uptodate(bh)) 2184 errors++; 2185 2186 /* drop our reference */ 2187 brelse(bh); 2188 2189 /* drop the reference from the wait == 0 run */ 2190 brelse(bh); 2191 continue; 2192 } else { 2193 btrfs_set_super_bytenr(sb, bytenr); 2194 2195 crc = ~(u32)0; 2196 crc = btrfs_csum_data(NULL, (char *)sb + 2197 BTRFS_CSUM_SIZE, crc, 2198 BTRFS_SUPER_INFO_SIZE - 2199 BTRFS_CSUM_SIZE); 2200 btrfs_csum_final(crc, sb->csum); 2201 2202 /* 2203 * one reference for us, and we leave it for the 2204 * caller 2205 */ 2206 bh = __getblk(device->bdev, bytenr / 4096, 2207 BTRFS_SUPER_INFO_SIZE); 2208 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE); 2209 2210 /* one reference for submit_bh */ 2211 get_bh(bh); 2212 2213 set_buffer_uptodate(bh); 2214 lock_buffer(bh); 2215 bh->b_end_io = btrfs_end_buffer_write_sync; 2216 } 2217 2218 if (i == last_barrier && do_barriers && device->barriers) { 2219 ret = submit_bh(WRITE_BARRIER, bh); 2220 if (ret == -EOPNOTSUPP) { 2221 printk("btrfs: disabling barriers on dev %s\n", 2222 device->name); 2223 set_buffer_uptodate(bh); 2224 device->barriers = 0; 2225 /* one reference for submit_bh */ 2226 get_bh(bh); 2227 lock_buffer(bh); 2228 ret = submit_bh(WRITE_SYNC, bh); 2229 } 2230 } else { 2231 ret = submit_bh(WRITE_SYNC, bh); 2232 } 2233 2234 if (ret) 2235 errors++; 2236 } 2237 return errors < i ? 0 : -1; 2238 } 2239 2240 int write_all_supers(struct btrfs_root *root, int max_mirrors) 2241 { 2242 struct list_head *head; 2243 struct btrfs_device *dev; 2244 struct btrfs_super_block *sb; 2245 struct btrfs_dev_item *dev_item; 2246 int ret; 2247 int do_barriers; 2248 int max_errors; 2249 int total_errors = 0; 2250 u64 flags; 2251 2252 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1; 2253 do_barriers = !btrfs_test_opt(root, NOBARRIER); 2254 2255 sb = &root->fs_info->super_for_commit; 2256 dev_item = &sb->dev_item; 2257 2258 mutex_lock(&root->fs_info->fs_devices->device_list_mutex); 2259 head = &root->fs_info->fs_devices->devices; 2260 list_for_each_entry(dev, head, dev_list) { 2261 if (!dev->bdev) { 2262 total_errors++; 2263 continue; 2264 } 2265 if (!dev->in_fs_metadata || !dev->writeable) 2266 continue; 2267 2268 btrfs_set_stack_device_generation(dev_item, 0); 2269 btrfs_set_stack_device_type(dev_item, dev->type); 2270 btrfs_set_stack_device_id(dev_item, dev->devid); 2271 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes); 2272 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used); 2273 btrfs_set_stack_device_io_align(dev_item, dev->io_align); 2274 btrfs_set_stack_device_io_width(dev_item, dev->io_width); 2275 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size); 2276 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE); 2277 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE); 2278 2279 flags = btrfs_super_flags(sb); 2280 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN); 2281 2282 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors); 2283 if (ret) 2284 total_errors++; 2285 } 2286 if (total_errors > max_errors) { 2287 printk(KERN_ERR "btrfs: %d errors while writing supers\n", 2288 total_errors); 2289 BUG(); 2290 } 2291 2292 total_errors = 0; 2293 list_for_each_entry(dev, head, dev_list) { 2294 if (!dev->bdev) 2295 continue; 2296 if (!dev->in_fs_metadata || !dev->writeable) 2297 continue; 2298 2299 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors); 2300 if (ret) 2301 total_errors++; 2302 } 2303 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); 2304 if (total_errors > max_errors) { 2305 printk(KERN_ERR "btrfs: %d errors while writing supers\n", 2306 total_errors); 2307 BUG(); 2308 } 2309 return 0; 2310 } 2311 2312 int write_ctree_super(struct btrfs_trans_handle *trans, 2313 struct btrfs_root *root, int max_mirrors) 2314 { 2315 int ret; 2316 2317 ret = write_all_supers(root, max_mirrors); 2318 return ret; 2319 } 2320 2321 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) 2322 { 2323 spin_lock(&fs_info->fs_roots_radix_lock); 2324 radix_tree_delete(&fs_info->fs_roots_radix, 2325 (unsigned long)root->root_key.objectid); 2326 spin_unlock(&fs_info->fs_roots_radix_lock); 2327 2328 if (btrfs_root_refs(&root->root_item) == 0) 2329 synchronize_srcu(&fs_info->subvol_srcu); 2330 2331 free_fs_root(root); 2332 return 0; 2333 } 2334 2335 static void free_fs_root(struct btrfs_root *root) 2336 { 2337 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); 2338 if (root->anon_super.s_dev) { 2339 down_write(&root->anon_super.s_umount); 2340 kill_anon_super(&root->anon_super); 2341 } 2342 free_extent_buffer(root->node); 2343 free_extent_buffer(root->commit_root); 2344 kfree(root->name); 2345 kfree(root); 2346 } 2347 2348 static int del_fs_roots(struct btrfs_fs_info *fs_info) 2349 { 2350 int ret; 2351 struct btrfs_root *gang[8]; 2352 int i; 2353 2354 while (!list_empty(&fs_info->dead_roots)) { 2355 gang[0] = list_entry(fs_info->dead_roots.next, 2356 struct btrfs_root, root_list); 2357 list_del(&gang[0]->root_list); 2358 2359 if (gang[0]->in_radix) { 2360 btrfs_free_fs_root(fs_info, gang[0]); 2361 } else { 2362 free_extent_buffer(gang[0]->node); 2363 free_extent_buffer(gang[0]->commit_root); 2364 kfree(gang[0]); 2365 } 2366 } 2367 2368 while (1) { 2369 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix, 2370 (void **)gang, 0, 2371 ARRAY_SIZE(gang)); 2372 if (!ret) 2373 break; 2374 for (i = 0; i < ret; i++) 2375 btrfs_free_fs_root(fs_info, gang[i]); 2376 } 2377 return 0; 2378 } 2379 2380 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info) 2381 { 2382 u64 root_objectid = 0; 2383 struct btrfs_root *gang[8]; 2384 int i; 2385 int ret; 2386 2387 while (1) { 2388 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix, 2389 (void **)gang, root_objectid, 2390 ARRAY_SIZE(gang)); 2391 if (!ret) 2392 break; 2393 2394 root_objectid = gang[ret - 1]->root_key.objectid + 1; 2395 for (i = 0; i < ret; i++) { 2396 root_objectid = gang[i]->root_key.objectid; 2397 btrfs_orphan_cleanup(gang[i]); 2398 } 2399 root_objectid++; 2400 } 2401 return 0; 2402 } 2403 2404 int btrfs_commit_super(struct btrfs_root *root) 2405 { 2406 struct btrfs_trans_handle *trans; 2407 int ret; 2408 2409 mutex_lock(&root->fs_info->cleaner_mutex); 2410 btrfs_run_delayed_iputs(root); 2411 btrfs_clean_old_snapshots(root); 2412 mutex_unlock(&root->fs_info->cleaner_mutex); 2413 2414 /* wait until ongoing cleanup work done */ 2415 down_write(&root->fs_info->cleanup_work_sem); 2416 up_write(&root->fs_info->cleanup_work_sem); 2417 2418 trans = btrfs_start_transaction(root, 1); 2419 ret = btrfs_commit_transaction(trans, root); 2420 BUG_ON(ret); 2421 /* run commit again to drop the original snapshot */ 2422 trans = btrfs_start_transaction(root, 1); 2423 btrfs_commit_transaction(trans, root); 2424 ret = btrfs_write_and_wait_transaction(NULL, root); 2425 BUG_ON(ret); 2426 2427 ret = write_ctree_super(NULL, root, 0); 2428 return ret; 2429 } 2430 2431 int close_ctree(struct btrfs_root *root) 2432 { 2433 struct btrfs_fs_info *fs_info = root->fs_info; 2434 int ret; 2435 2436 fs_info->closing = 1; 2437 smp_mb(); 2438 2439 kthread_stop(root->fs_info->transaction_kthread); 2440 kthread_stop(root->fs_info->cleaner_kthread); 2441 2442 if (!(fs_info->sb->s_flags & MS_RDONLY)) { 2443 ret = btrfs_commit_super(root); 2444 if (ret) 2445 printk(KERN_ERR "btrfs: commit super ret %d\n", ret); 2446 } 2447 2448 fs_info->closing = 2; 2449 smp_mb(); 2450 2451 if (fs_info->delalloc_bytes) { 2452 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n", 2453 (unsigned long long)fs_info->delalloc_bytes); 2454 } 2455 if (fs_info->total_ref_cache_size) { 2456 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n", 2457 (unsigned long long)fs_info->total_ref_cache_size); 2458 } 2459 2460 free_extent_buffer(fs_info->extent_root->node); 2461 free_extent_buffer(fs_info->extent_root->commit_root); 2462 free_extent_buffer(fs_info->tree_root->node); 2463 free_extent_buffer(fs_info->tree_root->commit_root); 2464 free_extent_buffer(root->fs_info->chunk_root->node); 2465 free_extent_buffer(root->fs_info->chunk_root->commit_root); 2466 free_extent_buffer(root->fs_info->dev_root->node); 2467 free_extent_buffer(root->fs_info->dev_root->commit_root); 2468 free_extent_buffer(root->fs_info->csum_root->node); 2469 free_extent_buffer(root->fs_info->csum_root->commit_root); 2470 2471 btrfs_free_block_groups(root->fs_info); 2472 2473 del_fs_roots(fs_info); 2474 2475 iput(fs_info->btree_inode); 2476 2477 btrfs_stop_workers(&fs_info->generic_worker); 2478 btrfs_stop_workers(&fs_info->fixup_workers); 2479 btrfs_stop_workers(&fs_info->delalloc_workers); 2480 btrfs_stop_workers(&fs_info->workers); 2481 btrfs_stop_workers(&fs_info->endio_workers); 2482 btrfs_stop_workers(&fs_info->endio_meta_workers); 2483 btrfs_stop_workers(&fs_info->endio_meta_write_workers); 2484 btrfs_stop_workers(&fs_info->endio_write_workers); 2485 btrfs_stop_workers(&fs_info->submit_workers); 2486 btrfs_stop_workers(&fs_info->enospc_workers); 2487 2488 btrfs_close_devices(fs_info->fs_devices); 2489 btrfs_mapping_tree_free(&fs_info->mapping_tree); 2490 2491 bdi_destroy(&fs_info->bdi); 2492 cleanup_srcu_struct(&fs_info->subvol_srcu); 2493 2494 kfree(fs_info->extent_root); 2495 kfree(fs_info->tree_root); 2496 kfree(fs_info->chunk_root); 2497 kfree(fs_info->dev_root); 2498 kfree(fs_info->csum_root); 2499 return 0; 2500 } 2501 2502 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid) 2503 { 2504 int ret; 2505 struct inode *btree_inode = buf->first_page->mapping->host; 2506 2507 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf, 2508 NULL); 2509 if (!ret) 2510 return ret; 2511 2512 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf, 2513 parent_transid); 2514 return !ret; 2515 } 2516 2517 int btrfs_set_buffer_uptodate(struct extent_buffer *buf) 2518 { 2519 struct inode *btree_inode = buf->first_page->mapping->host; 2520 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, 2521 buf); 2522 } 2523 2524 void btrfs_mark_buffer_dirty(struct extent_buffer *buf) 2525 { 2526 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; 2527 u64 transid = btrfs_header_generation(buf); 2528 struct inode *btree_inode = root->fs_info->btree_inode; 2529 int was_dirty; 2530 2531 btrfs_assert_tree_locked(buf); 2532 if (transid != root->fs_info->generation) { 2533 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, " 2534 "found %llu running %llu\n", 2535 (unsigned long long)buf->start, 2536 (unsigned long long)transid, 2537 (unsigned long long)root->fs_info->generation); 2538 WARN_ON(1); 2539 } 2540 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, 2541 buf); 2542 if (!was_dirty) { 2543 spin_lock(&root->fs_info->delalloc_lock); 2544 root->fs_info->dirty_metadata_bytes += buf->len; 2545 spin_unlock(&root->fs_info->delalloc_lock); 2546 } 2547 } 2548 2549 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr) 2550 { 2551 /* 2552 * looks as though older kernels can get into trouble with 2553 * this code, they end up stuck in balance_dirty_pages forever 2554 */ 2555 u64 num_dirty; 2556 unsigned long thresh = 32 * 1024 * 1024; 2557 2558 if (current->flags & PF_MEMALLOC) 2559 return; 2560 2561 num_dirty = root->fs_info->dirty_metadata_bytes; 2562 2563 if (num_dirty > thresh) { 2564 balance_dirty_pages_ratelimited_nr( 2565 root->fs_info->btree_inode->i_mapping, 1); 2566 } 2567 return; 2568 } 2569 2570 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid) 2571 { 2572 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; 2573 int ret; 2574 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); 2575 if (ret == 0) 2576 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); 2577 return ret; 2578 } 2579 2580 int btree_lock_page_hook(struct page *page) 2581 { 2582 struct inode *inode = page->mapping->host; 2583 struct btrfs_root *root = BTRFS_I(inode)->root; 2584 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2585 struct extent_buffer *eb; 2586 unsigned long len; 2587 u64 bytenr = page_offset(page); 2588 2589 if (page->private == EXTENT_PAGE_PRIVATE) 2590 goto out; 2591 2592 len = page->private >> 2; 2593 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS); 2594 if (!eb) 2595 goto out; 2596 2597 btrfs_tree_lock(eb); 2598 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); 2599 2600 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { 2601 spin_lock(&root->fs_info->delalloc_lock); 2602 if (root->fs_info->dirty_metadata_bytes >= eb->len) 2603 root->fs_info->dirty_metadata_bytes -= eb->len; 2604 else 2605 WARN_ON(1); 2606 spin_unlock(&root->fs_info->delalloc_lock); 2607 } 2608 2609 btrfs_tree_unlock(eb); 2610 free_extent_buffer(eb); 2611 out: 2612 lock_page(page); 2613 return 0; 2614 } 2615 2616 static struct extent_io_ops btree_extent_io_ops = { 2617 .write_cache_pages_lock_hook = btree_lock_page_hook, 2618 .readpage_end_io_hook = btree_readpage_end_io_hook, 2619 .submit_bio_hook = btree_submit_bio_hook, 2620 /* note we're sharing with inode.c for the merge bio hook */ 2621 .merge_bio_hook = btrfs_merge_bio_hook, 2622 }; 2623