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 "compat.h" 30 #include "crc32c.h" 31 #include "ctree.h" 32 #include "disk-io.h" 33 #include "transaction.h" 34 #include "btrfs_inode.h" 35 #include "volumes.h" 36 #include "print-tree.h" 37 #include "async-thread.h" 38 #include "locking.h" 39 #include "ref-cache.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 46 /* 47 * end_io_wq structs are used to do processing in task context when an IO is 48 * complete. This is used during reads to verify checksums, and it is used 49 * by writes to insert metadata for new file extents after IO is complete. 50 */ 51 struct end_io_wq { 52 struct bio *bio; 53 bio_end_io_t *end_io; 54 void *private; 55 struct btrfs_fs_info *info; 56 int error; 57 int metadata; 58 struct list_head list; 59 struct btrfs_work work; 60 }; 61 62 /* 63 * async submit bios are used to offload expensive checksumming 64 * onto the worker threads. They checksum file and metadata bios 65 * just before they are sent down the IO stack. 66 */ 67 struct async_submit_bio { 68 struct inode *inode; 69 struct bio *bio; 70 struct list_head list; 71 extent_submit_bio_hook_t *submit_bio_start; 72 extent_submit_bio_hook_t *submit_bio_done; 73 int rw; 74 int mirror_num; 75 unsigned long bio_flags; 76 struct btrfs_work work; 77 }; 78 79 /* These are used to set the lockdep class on the extent buffer locks. 80 * The class is set by the readpage_end_io_hook after the buffer has 81 * passed csum validation but before the pages are unlocked. 82 * 83 * The lockdep class is also set by btrfs_init_new_buffer on freshly 84 * allocated blocks. 85 * 86 * The class is based on the level in the tree block, which allows lockdep 87 * to know that lower nodes nest inside the locks of higher nodes. 88 * 89 * We also add a check to make sure the highest level of the tree is 90 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this 91 * code needs update as well. 92 */ 93 #ifdef CONFIG_DEBUG_LOCK_ALLOC 94 # if BTRFS_MAX_LEVEL != 8 95 # error 96 # endif 97 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1]; 98 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = { 99 /* leaf */ 100 "btrfs-extent-00", 101 "btrfs-extent-01", 102 "btrfs-extent-02", 103 "btrfs-extent-03", 104 "btrfs-extent-04", 105 "btrfs-extent-05", 106 "btrfs-extent-06", 107 "btrfs-extent-07", 108 /* highest possible level */ 109 "btrfs-extent-08", 110 }; 111 #endif 112 113 /* 114 * extents on the btree inode are pretty simple, there's one extent 115 * that covers the entire device 116 */ 117 static struct extent_map *btree_get_extent(struct inode *inode, 118 struct page *page, size_t page_offset, u64 start, u64 len, 119 int create) 120 { 121 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 122 struct extent_map *em; 123 int ret; 124 125 spin_lock(&em_tree->lock); 126 em = lookup_extent_mapping(em_tree, start, len); 127 if (em) { 128 em->bdev = 129 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; 130 spin_unlock(&em_tree->lock); 131 goto out; 132 } 133 spin_unlock(&em_tree->lock); 134 135 em = alloc_extent_map(GFP_NOFS); 136 if (!em) { 137 em = ERR_PTR(-ENOMEM); 138 goto out; 139 } 140 em->start = 0; 141 em->len = (u64)-1; 142 em->block_len = (u64)-1; 143 em->block_start = 0; 144 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; 145 146 spin_lock(&em_tree->lock); 147 ret = add_extent_mapping(em_tree, em); 148 if (ret == -EEXIST) { 149 u64 failed_start = em->start; 150 u64 failed_len = em->len; 151 152 free_extent_map(em); 153 em = lookup_extent_mapping(em_tree, start, len); 154 if (em) { 155 ret = 0; 156 } else { 157 em = lookup_extent_mapping(em_tree, failed_start, 158 failed_len); 159 ret = -EIO; 160 } 161 } else if (ret) { 162 free_extent_map(em); 163 em = NULL; 164 } 165 spin_unlock(&em_tree->lock); 166 167 if (ret) 168 em = ERR_PTR(ret); 169 out: 170 return em; 171 } 172 173 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len) 174 { 175 return btrfs_crc32c(seed, data, len); 176 } 177 178 void btrfs_csum_final(u32 crc, char *result) 179 { 180 *(__le32 *)result = ~cpu_to_le32(crc); 181 } 182 183 /* 184 * compute the csum for a btree block, and either verify it or write it 185 * into the csum field of the block. 186 */ 187 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, 188 int verify) 189 { 190 u16 csum_size = 191 btrfs_super_csum_size(&root->fs_info->super_copy); 192 char *result = NULL; 193 unsigned long len; 194 unsigned long cur_len; 195 unsigned long offset = BTRFS_CSUM_SIZE; 196 char *map_token = NULL; 197 char *kaddr; 198 unsigned long map_start; 199 unsigned long map_len; 200 int err; 201 u32 crc = ~(u32)0; 202 unsigned long inline_result; 203 204 len = buf->len - offset; 205 while (len > 0) { 206 err = map_private_extent_buffer(buf, offset, 32, 207 &map_token, &kaddr, 208 &map_start, &map_len, KM_USER0); 209 if (err) 210 return 1; 211 cur_len = min(len, map_len - (offset - map_start)); 212 crc = btrfs_csum_data(root, kaddr + offset - map_start, 213 crc, cur_len); 214 len -= cur_len; 215 offset += cur_len; 216 unmap_extent_buffer(buf, map_token, KM_USER0); 217 } 218 if (csum_size > sizeof(inline_result)) { 219 result = kzalloc(csum_size * sizeof(char), GFP_NOFS); 220 if (!result) 221 return 1; 222 } else { 223 result = (char *)&inline_result; 224 } 225 226 btrfs_csum_final(crc, result); 227 228 if (verify) { 229 if (memcmp_extent_buffer(buf, result, 0, csum_size)) { 230 u32 val; 231 u32 found = 0; 232 memcpy(&found, result, csum_size); 233 234 read_extent_buffer(buf, &val, 0, csum_size); 235 printk(KERN_INFO "btrfs: %s checksum verify failed " 236 "on %llu wanted %X found %X level %d\n", 237 root->fs_info->sb->s_id, 238 buf->start, val, found, btrfs_header_level(buf)); 239 if (result != (char *)&inline_result) 240 kfree(result); 241 return 1; 242 } 243 } else { 244 write_extent_buffer(buf, result, 0, csum_size); 245 } 246 if (result != (char *)&inline_result) 247 kfree(result); 248 return 0; 249 } 250 251 /* 252 * we can't consider a given block up to date unless the transid of the 253 * block matches the transid in the parent node's pointer. This is how we 254 * detect blocks that either didn't get written at all or got written 255 * in the wrong place. 256 */ 257 static int verify_parent_transid(struct extent_io_tree *io_tree, 258 struct extent_buffer *eb, u64 parent_transid) 259 { 260 int ret; 261 262 if (!parent_transid || btrfs_header_generation(eb) == parent_transid) 263 return 0; 264 265 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS); 266 if (extent_buffer_uptodate(io_tree, eb) && 267 btrfs_header_generation(eb) == parent_transid) { 268 ret = 0; 269 goto out; 270 } 271 printk("parent transid verify failed on %llu wanted %llu found %llu\n", 272 (unsigned long long)eb->start, 273 (unsigned long long)parent_transid, 274 (unsigned long long)btrfs_header_generation(eb)); 275 ret = 1; 276 clear_extent_buffer_uptodate(io_tree, eb); 277 out: 278 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1, 279 GFP_NOFS); 280 return ret; 281 } 282 283 /* 284 * helper to read a given tree block, doing retries as required when 285 * the checksums don't match and we have alternate mirrors to try. 286 */ 287 static int btree_read_extent_buffer_pages(struct btrfs_root *root, 288 struct extent_buffer *eb, 289 u64 start, u64 parent_transid) 290 { 291 struct extent_io_tree *io_tree; 292 int ret; 293 int num_copies = 0; 294 int mirror_num = 0; 295 296 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree; 297 while (1) { 298 ret = read_extent_buffer_pages(io_tree, eb, start, 1, 299 btree_get_extent, mirror_num); 300 if (!ret && 301 !verify_parent_transid(io_tree, eb, parent_transid)) 302 return ret; 303 304 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree, 305 eb->start, eb->len); 306 if (num_copies == 1) 307 return ret; 308 309 mirror_num++; 310 if (mirror_num > num_copies) 311 return ret; 312 } 313 return -EIO; 314 } 315 316 /* 317 * checksum a dirty tree block before IO. This has extra checks to make sure 318 * we only fill in the checksum field in the first page of a multi-page block 319 */ 320 321 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page) 322 { 323 struct extent_io_tree *tree; 324 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 325 u64 found_start; 326 int found_level; 327 unsigned long len; 328 struct extent_buffer *eb; 329 int ret; 330 331 tree = &BTRFS_I(page->mapping->host)->io_tree; 332 333 if (page->private == EXTENT_PAGE_PRIVATE) 334 goto out; 335 if (!page->private) 336 goto out; 337 len = page->private >> 2; 338 WARN_ON(len == 0); 339 340 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS); 341 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE, 342 btrfs_header_generation(eb)); 343 BUG_ON(ret); 344 found_start = btrfs_header_bytenr(eb); 345 if (found_start != start) { 346 WARN_ON(1); 347 goto err; 348 } 349 if (eb->first_page != page) { 350 WARN_ON(1); 351 goto err; 352 } 353 if (!PageUptodate(page)) { 354 WARN_ON(1); 355 goto err; 356 } 357 found_level = btrfs_header_level(eb); 358 359 csum_tree_block(root, eb, 0); 360 err: 361 free_extent_buffer(eb); 362 out: 363 return 0; 364 } 365 366 static int check_tree_block_fsid(struct btrfs_root *root, 367 struct extent_buffer *eb) 368 { 369 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 370 u8 fsid[BTRFS_UUID_SIZE]; 371 int ret = 1; 372 373 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb), 374 BTRFS_FSID_SIZE); 375 while (fs_devices) { 376 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) { 377 ret = 0; 378 break; 379 } 380 fs_devices = fs_devices->seed; 381 } 382 return ret; 383 } 384 385 #ifdef CONFIG_DEBUG_LOCK_ALLOC 386 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level) 387 { 388 lockdep_set_class_and_name(&eb->lock, 389 &btrfs_eb_class[level], 390 btrfs_eb_name[level]); 391 } 392 #endif 393 394 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, 395 struct extent_state *state) 396 { 397 struct extent_io_tree *tree; 398 u64 found_start; 399 int found_level; 400 unsigned long len; 401 struct extent_buffer *eb; 402 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 403 int ret = 0; 404 405 tree = &BTRFS_I(page->mapping->host)->io_tree; 406 if (page->private == EXTENT_PAGE_PRIVATE) 407 goto out; 408 if (!page->private) 409 goto out; 410 411 len = page->private >> 2; 412 WARN_ON(len == 0); 413 414 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS); 415 416 found_start = btrfs_header_bytenr(eb); 417 if (found_start != start) { 418 printk(KERN_INFO "btrfs bad tree block start %llu %llu\n", 419 (unsigned long long)found_start, 420 (unsigned long long)eb->start); 421 ret = -EIO; 422 goto err; 423 } 424 if (eb->first_page != page) { 425 printk(KERN_INFO "btrfs bad first page %lu %lu\n", 426 eb->first_page->index, page->index); 427 WARN_ON(1); 428 ret = -EIO; 429 goto err; 430 } 431 if (check_tree_block_fsid(root, eb)) { 432 printk(KERN_INFO "btrfs bad fsid on block %llu\n", 433 (unsigned long long)eb->start); 434 ret = -EIO; 435 goto err; 436 } 437 found_level = btrfs_header_level(eb); 438 439 btrfs_set_buffer_lockdep_class(eb, found_level); 440 441 ret = csum_tree_block(root, eb, 1); 442 if (ret) 443 ret = -EIO; 444 445 end = min_t(u64, eb->len, PAGE_CACHE_SIZE); 446 end = eb->start + end - 1; 447 err: 448 free_extent_buffer(eb); 449 out: 450 return ret; 451 } 452 453 static void end_workqueue_bio(struct bio *bio, int err) 454 { 455 struct end_io_wq *end_io_wq = bio->bi_private; 456 struct btrfs_fs_info *fs_info; 457 458 fs_info = end_io_wq->info; 459 end_io_wq->error = err; 460 end_io_wq->work.func = end_workqueue_fn; 461 end_io_wq->work.flags = 0; 462 463 if (bio->bi_rw & (1 << BIO_RW)) { 464 if (end_io_wq->metadata) 465 btrfs_queue_worker(&fs_info->endio_meta_write_workers, 466 &end_io_wq->work); 467 else 468 btrfs_queue_worker(&fs_info->endio_write_workers, 469 &end_io_wq->work); 470 } else { 471 if (end_io_wq->metadata) 472 btrfs_queue_worker(&fs_info->endio_meta_workers, 473 &end_io_wq->work); 474 else 475 btrfs_queue_worker(&fs_info->endio_workers, 476 &end_io_wq->work); 477 } 478 } 479 480 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio, 481 int metadata) 482 { 483 struct end_io_wq *end_io_wq; 484 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS); 485 if (!end_io_wq) 486 return -ENOMEM; 487 488 end_io_wq->private = bio->bi_private; 489 end_io_wq->end_io = bio->bi_end_io; 490 end_io_wq->info = info; 491 end_io_wq->error = 0; 492 end_io_wq->bio = bio; 493 end_io_wq->metadata = metadata; 494 495 bio->bi_private = end_io_wq; 496 bio->bi_end_io = end_workqueue_bio; 497 return 0; 498 } 499 500 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info) 501 { 502 unsigned long limit = min_t(unsigned long, 503 info->workers.max_workers, 504 info->fs_devices->open_devices); 505 return 256 * limit; 506 } 507 508 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone) 509 { 510 return atomic_read(&info->nr_async_bios) > 511 btrfs_async_submit_limit(info); 512 } 513 514 static void run_one_async_start(struct btrfs_work *work) 515 { 516 struct btrfs_fs_info *fs_info; 517 struct async_submit_bio *async; 518 519 async = container_of(work, struct async_submit_bio, work); 520 fs_info = BTRFS_I(async->inode)->root->fs_info; 521 async->submit_bio_start(async->inode, async->rw, async->bio, 522 async->mirror_num, async->bio_flags); 523 } 524 525 static void run_one_async_done(struct btrfs_work *work) 526 { 527 struct btrfs_fs_info *fs_info; 528 struct async_submit_bio *async; 529 int limit; 530 531 async = container_of(work, struct async_submit_bio, work); 532 fs_info = BTRFS_I(async->inode)->root->fs_info; 533 534 limit = btrfs_async_submit_limit(fs_info); 535 limit = limit * 2 / 3; 536 537 atomic_dec(&fs_info->nr_async_submits); 538 539 if (atomic_read(&fs_info->nr_async_submits) < limit && 540 waitqueue_active(&fs_info->async_submit_wait)) 541 wake_up(&fs_info->async_submit_wait); 542 543 async->submit_bio_done(async->inode, async->rw, async->bio, 544 async->mirror_num, async->bio_flags); 545 } 546 547 static void run_one_async_free(struct btrfs_work *work) 548 { 549 struct async_submit_bio *async; 550 551 async = container_of(work, struct async_submit_bio, work); 552 kfree(async); 553 } 554 555 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode, 556 int rw, struct bio *bio, int mirror_num, 557 unsigned long bio_flags, 558 extent_submit_bio_hook_t *submit_bio_start, 559 extent_submit_bio_hook_t *submit_bio_done) 560 { 561 struct async_submit_bio *async; 562 563 async = kmalloc(sizeof(*async), GFP_NOFS); 564 if (!async) 565 return -ENOMEM; 566 567 async->inode = inode; 568 async->rw = rw; 569 async->bio = bio; 570 async->mirror_num = mirror_num; 571 async->submit_bio_start = submit_bio_start; 572 async->submit_bio_done = submit_bio_done; 573 574 async->work.func = run_one_async_start; 575 async->work.ordered_func = run_one_async_done; 576 async->work.ordered_free = run_one_async_free; 577 578 async->work.flags = 0; 579 async->bio_flags = bio_flags; 580 581 atomic_inc(&fs_info->nr_async_submits); 582 583 if (rw & (1 << BIO_RW_SYNCIO)) 584 btrfs_set_work_high_prio(&async->work); 585 586 btrfs_queue_worker(&fs_info->workers, &async->work); 587 #if 0 588 int limit = btrfs_async_submit_limit(fs_info); 589 if (atomic_read(&fs_info->nr_async_submits) > limit) { 590 wait_event_timeout(fs_info->async_submit_wait, 591 (atomic_read(&fs_info->nr_async_submits) < limit), 592 HZ/10); 593 594 wait_event_timeout(fs_info->async_submit_wait, 595 (atomic_read(&fs_info->nr_async_bios) < limit), 596 HZ/10); 597 } 598 #endif 599 while (atomic_read(&fs_info->async_submit_draining) && 600 atomic_read(&fs_info->nr_async_submits)) { 601 wait_event(fs_info->async_submit_wait, 602 (atomic_read(&fs_info->nr_async_submits) == 0)); 603 } 604 605 return 0; 606 } 607 608 static int btree_csum_one_bio(struct bio *bio) 609 { 610 struct bio_vec *bvec = bio->bi_io_vec; 611 int bio_index = 0; 612 struct btrfs_root *root; 613 614 WARN_ON(bio->bi_vcnt <= 0); 615 while (bio_index < bio->bi_vcnt) { 616 root = BTRFS_I(bvec->bv_page->mapping->host)->root; 617 csum_dirty_buffer(root, bvec->bv_page); 618 bio_index++; 619 bvec++; 620 } 621 return 0; 622 } 623 624 static int __btree_submit_bio_start(struct inode *inode, int rw, 625 struct bio *bio, int mirror_num, 626 unsigned long bio_flags) 627 { 628 /* 629 * when we're called for a write, we're already in the async 630 * submission context. Just jump into btrfs_map_bio 631 */ 632 btree_csum_one_bio(bio); 633 return 0; 634 } 635 636 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 637 int mirror_num, unsigned long bio_flags) 638 { 639 /* 640 * when we're called for a write, we're already in the async 641 * submission context. Just jump into btrfs_map_bio 642 */ 643 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1); 644 } 645 646 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 647 int mirror_num, unsigned long bio_flags) 648 { 649 int ret; 650 651 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info, 652 bio, 1); 653 BUG_ON(ret); 654 655 if (!(rw & (1 << BIO_RW))) { 656 /* 657 * called for a read, do the setup so that checksum validation 658 * can happen in the async kernel threads 659 */ 660 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, 661 mirror_num, 0); 662 } 663 664 /* 665 * kthread helpers are used to submit writes so that checksumming 666 * can happen in parallel across all CPUs 667 */ 668 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 669 inode, rw, bio, mirror_num, 0, 670 __btree_submit_bio_start, 671 __btree_submit_bio_done); 672 } 673 674 static int btree_writepage(struct page *page, struct writeback_control *wbc) 675 { 676 struct extent_io_tree *tree; 677 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 678 struct extent_buffer *eb; 679 int was_dirty; 680 681 tree = &BTRFS_I(page->mapping->host)->io_tree; 682 if (!(current->flags & PF_MEMALLOC)) { 683 return extent_write_full_page(tree, page, 684 btree_get_extent, wbc); 685 } 686 687 redirty_page_for_writepage(wbc, page); 688 eb = btrfs_find_tree_block(root, page_offset(page), 689 PAGE_CACHE_SIZE); 690 WARN_ON(!eb); 691 692 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); 693 if (!was_dirty) { 694 spin_lock(&root->fs_info->delalloc_lock); 695 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE; 696 spin_unlock(&root->fs_info->delalloc_lock); 697 } 698 free_extent_buffer(eb); 699 700 unlock_page(page); 701 return 0; 702 } 703 704 static int btree_writepages(struct address_space *mapping, 705 struct writeback_control *wbc) 706 { 707 struct extent_io_tree *tree; 708 tree = &BTRFS_I(mapping->host)->io_tree; 709 if (wbc->sync_mode == WB_SYNC_NONE) { 710 struct btrfs_root *root = BTRFS_I(mapping->host)->root; 711 u64 num_dirty; 712 unsigned long thresh = 32 * 1024 * 1024; 713 714 if (wbc->for_kupdate) 715 return 0; 716 717 /* this is a bit racy, but that's ok */ 718 num_dirty = root->fs_info->dirty_metadata_bytes; 719 if (num_dirty < thresh) 720 return 0; 721 } 722 return extent_writepages(tree, mapping, btree_get_extent, wbc); 723 } 724 725 static int btree_readpage(struct file *file, struct page *page) 726 { 727 struct extent_io_tree *tree; 728 tree = &BTRFS_I(page->mapping->host)->io_tree; 729 return extent_read_full_page(tree, page, btree_get_extent); 730 } 731 732 static int btree_releasepage(struct page *page, gfp_t gfp_flags) 733 { 734 struct extent_io_tree *tree; 735 struct extent_map_tree *map; 736 int ret; 737 738 if (PageWriteback(page) || PageDirty(page)) 739 return 0; 740 741 tree = &BTRFS_I(page->mapping->host)->io_tree; 742 map = &BTRFS_I(page->mapping->host)->extent_tree; 743 744 ret = try_release_extent_state(map, tree, page, gfp_flags); 745 if (!ret) 746 return 0; 747 748 ret = try_release_extent_buffer(tree, page); 749 if (ret == 1) { 750 ClearPagePrivate(page); 751 set_page_private(page, 0); 752 page_cache_release(page); 753 } 754 755 return ret; 756 } 757 758 static void btree_invalidatepage(struct page *page, unsigned long offset) 759 { 760 struct extent_io_tree *tree; 761 tree = &BTRFS_I(page->mapping->host)->io_tree; 762 extent_invalidatepage(tree, page, offset); 763 btree_releasepage(page, GFP_NOFS); 764 if (PagePrivate(page)) { 765 printk(KERN_WARNING "btrfs warning page private not zero " 766 "on page %llu\n", (unsigned long long)page_offset(page)); 767 ClearPagePrivate(page); 768 set_page_private(page, 0); 769 page_cache_release(page); 770 } 771 } 772 773 #if 0 774 static int btree_writepage(struct page *page, struct writeback_control *wbc) 775 { 776 struct buffer_head *bh; 777 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 778 struct buffer_head *head; 779 if (!page_has_buffers(page)) { 780 create_empty_buffers(page, root->fs_info->sb->s_blocksize, 781 (1 << BH_Dirty)|(1 << BH_Uptodate)); 782 } 783 head = page_buffers(page); 784 bh = head; 785 do { 786 if (buffer_dirty(bh)) 787 csum_tree_block(root, bh, 0); 788 bh = bh->b_this_page; 789 } while (bh != head); 790 return block_write_full_page(page, btree_get_block, wbc); 791 } 792 #endif 793 794 static struct address_space_operations btree_aops = { 795 .readpage = btree_readpage, 796 .writepage = btree_writepage, 797 .writepages = btree_writepages, 798 .releasepage = btree_releasepage, 799 .invalidatepage = btree_invalidatepage, 800 .sync_page = block_sync_page, 801 }; 802 803 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, 804 u64 parent_transid) 805 { 806 struct extent_buffer *buf = NULL; 807 struct inode *btree_inode = root->fs_info->btree_inode; 808 int ret = 0; 809 810 buf = btrfs_find_create_tree_block(root, bytenr, blocksize); 811 if (!buf) 812 return 0; 813 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, 814 buf, 0, 0, btree_get_extent, 0); 815 free_extent_buffer(buf); 816 return ret; 817 } 818 819 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root, 820 u64 bytenr, u32 blocksize) 821 { 822 struct inode *btree_inode = root->fs_info->btree_inode; 823 struct extent_buffer *eb; 824 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree, 825 bytenr, blocksize, GFP_NOFS); 826 return eb; 827 } 828 829 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root, 830 u64 bytenr, u32 blocksize) 831 { 832 struct inode *btree_inode = root->fs_info->btree_inode; 833 struct extent_buffer *eb; 834 835 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree, 836 bytenr, blocksize, NULL, GFP_NOFS); 837 return eb; 838 } 839 840 841 int btrfs_write_tree_block(struct extent_buffer *buf) 842 { 843 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start, 844 buf->start + buf->len - 1, WB_SYNC_ALL); 845 } 846 847 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf) 848 { 849 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping, 850 buf->start, buf->start + buf->len - 1); 851 } 852 853 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, 854 u32 blocksize, u64 parent_transid) 855 { 856 struct extent_buffer *buf = NULL; 857 struct inode *btree_inode = root->fs_info->btree_inode; 858 struct extent_io_tree *io_tree; 859 int ret; 860 861 io_tree = &BTRFS_I(btree_inode)->io_tree; 862 863 buf = btrfs_find_create_tree_block(root, bytenr, blocksize); 864 if (!buf) 865 return NULL; 866 867 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); 868 869 if (ret == 0) 870 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); 871 else 872 WARN_ON(1); 873 return buf; 874 875 } 876 877 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, 878 struct extent_buffer *buf) 879 { 880 struct inode *btree_inode = root->fs_info->btree_inode; 881 if (btrfs_header_generation(buf) == 882 root->fs_info->running_transaction->transid) { 883 btrfs_assert_tree_locked(buf); 884 885 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) { 886 spin_lock(&root->fs_info->delalloc_lock); 887 if (root->fs_info->dirty_metadata_bytes >= buf->len) 888 root->fs_info->dirty_metadata_bytes -= buf->len; 889 else 890 WARN_ON(1); 891 spin_unlock(&root->fs_info->delalloc_lock); 892 } 893 894 /* ugh, clear_extent_buffer_dirty needs to lock the page */ 895 btrfs_set_lock_blocking(buf); 896 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, 897 buf); 898 } 899 return 0; 900 } 901 902 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize, 903 u32 stripesize, struct btrfs_root *root, 904 struct btrfs_fs_info *fs_info, 905 u64 objectid) 906 { 907 root->node = NULL; 908 root->commit_root = NULL; 909 root->ref_tree = NULL; 910 root->sectorsize = sectorsize; 911 root->nodesize = nodesize; 912 root->leafsize = leafsize; 913 root->stripesize = stripesize; 914 root->ref_cows = 0; 915 root->track_dirty = 0; 916 917 root->fs_info = fs_info; 918 root->objectid = objectid; 919 root->last_trans = 0; 920 root->highest_inode = 0; 921 root->last_inode_alloc = 0; 922 root->name = NULL; 923 root->in_sysfs = 0; 924 925 INIT_LIST_HEAD(&root->dirty_list); 926 INIT_LIST_HEAD(&root->orphan_list); 927 INIT_LIST_HEAD(&root->dead_list); 928 spin_lock_init(&root->node_lock); 929 spin_lock_init(&root->list_lock); 930 mutex_init(&root->objectid_mutex); 931 mutex_init(&root->log_mutex); 932 init_waitqueue_head(&root->log_writer_wait); 933 init_waitqueue_head(&root->log_commit_wait[0]); 934 init_waitqueue_head(&root->log_commit_wait[1]); 935 atomic_set(&root->log_commit[0], 0); 936 atomic_set(&root->log_commit[1], 0); 937 atomic_set(&root->log_writers, 0); 938 root->log_batch = 0; 939 root->log_transid = 0; 940 extent_io_tree_init(&root->dirty_log_pages, 941 fs_info->btree_inode->i_mapping, GFP_NOFS); 942 943 btrfs_leaf_ref_tree_init(&root->ref_tree_struct); 944 root->ref_tree = &root->ref_tree_struct; 945 946 memset(&root->root_key, 0, sizeof(root->root_key)); 947 memset(&root->root_item, 0, sizeof(root->root_item)); 948 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress)); 949 memset(&root->root_kobj, 0, sizeof(root->root_kobj)); 950 root->defrag_trans_start = fs_info->generation; 951 init_completion(&root->kobj_unregister); 952 root->defrag_running = 0; 953 root->defrag_level = 0; 954 root->root_key.objectid = objectid; 955 root->anon_super.s_root = NULL; 956 root->anon_super.s_dev = 0; 957 INIT_LIST_HEAD(&root->anon_super.s_list); 958 INIT_LIST_HEAD(&root->anon_super.s_instances); 959 init_rwsem(&root->anon_super.s_umount); 960 961 return 0; 962 } 963 964 static int find_and_setup_root(struct btrfs_root *tree_root, 965 struct btrfs_fs_info *fs_info, 966 u64 objectid, 967 struct btrfs_root *root) 968 { 969 int ret; 970 u32 blocksize; 971 u64 generation; 972 973 __setup_root(tree_root->nodesize, tree_root->leafsize, 974 tree_root->sectorsize, tree_root->stripesize, 975 root, fs_info, objectid); 976 ret = btrfs_find_last_root(tree_root, objectid, 977 &root->root_item, &root->root_key); 978 BUG_ON(ret); 979 980 generation = btrfs_root_generation(&root->root_item); 981 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); 982 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), 983 blocksize, generation); 984 BUG_ON(!root->node); 985 return 0; 986 } 987 988 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, 989 struct btrfs_fs_info *fs_info) 990 { 991 struct extent_buffer *eb; 992 struct btrfs_root *log_root_tree = fs_info->log_root_tree; 993 u64 start = 0; 994 u64 end = 0; 995 int ret; 996 997 if (!log_root_tree) 998 return 0; 999 1000 while (1) { 1001 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages, 1002 0, &start, &end, EXTENT_DIRTY); 1003 if (ret) 1004 break; 1005 1006 clear_extent_dirty(&log_root_tree->dirty_log_pages, 1007 start, end, GFP_NOFS); 1008 } 1009 eb = fs_info->log_root_tree->node; 1010 1011 WARN_ON(btrfs_header_level(eb) != 0); 1012 WARN_ON(btrfs_header_nritems(eb) != 0); 1013 1014 ret = btrfs_free_reserved_extent(fs_info->tree_root, 1015 eb->start, eb->len); 1016 BUG_ON(ret); 1017 1018 free_extent_buffer(eb); 1019 kfree(fs_info->log_root_tree); 1020 fs_info->log_root_tree = NULL; 1021 return 0; 1022 } 1023 1024 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans, 1025 struct btrfs_fs_info *fs_info) 1026 { 1027 struct btrfs_root *root; 1028 struct btrfs_root *tree_root = fs_info->tree_root; 1029 struct extent_buffer *leaf; 1030 1031 root = kzalloc(sizeof(*root), GFP_NOFS); 1032 if (!root) 1033 return ERR_PTR(-ENOMEM); 1034 1035 __setup_root(tree_root->nodesize, tree_root->leafsize, 1036 tree_root->sectorsize, tree_root->stripesize, 1037 root, fs_info, BTRFS_TREE_LOG_OBJECTID); 1038 1039 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID; 1040 root->root_key.type = BTRFS_ROOT_ITEM_KEY; 1041 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID; 1042 /* 1043 * log trees do not get reference counted because they go away 1044 * before a real commit is actually done. They do store pointers 1045 * to file data extents, and those reference counts still get 1046 * updated (along with back refs to the log tree). 1047 */ 1048 root->ref_cows = 0; 1049 1050 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 1051 0, BTRFS_TREE_LOG_OBJECTID, 1052 trans->transid, 0, 0, 0); 1053 if (IS_ERR(leaf)) { 1054 kfree(root); 1055 return ERR_CAST(leaf); 1056 } 1057 1058 root->node = leaf; 1059 btrfs_set_header_nritems(root->node, 0); 1060 btrfs_set_header_level(root->node, 0); 1061 btrfs_set_header_bytenr(root->node, root->node->start); 1062 btrfs_set_header_generation(root->node, trans->transid); 1063 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID); 1064 1065 write_extent_buffer(root->node, root->fs_info->fsid, 1066 (unsigned long)btrfs_header_fsid(root->node), 1067 BTRFS_FSID_SIZE); 1068 btrfs_mark_buffer_dirty(root->node); 1069 btrfs_tree_unlock(root->node); 1070 return root; 1071 } 1072 1073 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, 1074 struct btrfs_fs_info *fs_info) 1075 { 1076 struct btrfs_root *log_root; 1077 1078 log_root = alloc_log_tree(trans, fs_info); 1079 if (IS_ERR(log_root)) 1080 return PTR_ERR(log_root); 1081 WARN_ON(fs_info->log_root_tree); 1082 fs_info->log_root_tree = log_root; 1083 return 0; 1084 } 1085 1086 int btrfs_add_log_tree(struct btrfs_trans_handle *trans, 1087 struct btrfs_root *root) 1088 { 1089 struct btrfs_root *log_root; 1090 struct btrfs_inode_item *inode_item; 1091 1092 log_root = alloc_log_tree(trans, root->fs_info); 1093 if (IS_ERR(log_root)) 1094 return PTR_ERR(log_root); 1095 1096 log_root->last_trans = trans->transid; 1097 log_root->root_key.offset = root->root_key.objectid; 1098 1099 inode_item = &log_root->root_item.inode; 1100 inode_item->generation = cpu_to_le64(1); 1101 inode_item->size = cpu_to_le64(3); 1102 inode_item->nlink = cpu_to_le32(1); 1103 inode_item->nbytes = cpu_to_le64(root->leafsize); 1104 inode_item->mode = cpu_to_le32(S_IFDIR | 0755); 1105 1106 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start); 1107 btrfs_set_root_generation(&log_root->root_item, trans->transid); 1108 1109 WARN_ON(root->log_root); 1110 root->log_root = log_root; 1111 root->log_transid = 0; 1112 return 0; 1113 } 1114 1115 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, 1116 struct btrfs_key *location) 1117 { 1118 struct btrfs_root *root; 1119 struct btrfs_fs_info *fs_info = tree_root->fs_info; 1120 struct btrfs_path *path; 1121 struct extent_buffer *l; 1122 u64 highest_inode; 1123 u64 generation; 1124 u32 blocksize; 1125 int ret = 0; 1126 1127 root = kzalloc(sizeof(*root), GFP_NOFS); 1128 if (!root) 1129 return ERR_PTR(-ENOMEM); 1130 if (location->offset == (u64)-1) { 1131 ret = find_and_setup_root(tree_root, fs_info, 1132 location->objectid, root); 1133 if (ret) { 1134 kfree(root); 1135 return ERR_PTR(ret); 1136 } 1137 goto insert; 1138 } 1139 1140 __setup_root(tree_root->nodesize, tree_root->leafsize, 1141 tree_root->sectorsize, tree_root->stripesize, 1142 root, fs_info, location->objectid); 1143 1144 path = btrfs_alloc_path(); 1145 BUG_ON(!path); 1146 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0); 1147 if (ret != 0) { 1148 if (ret > 0) 1149 ret = -ENOENT; 1150 goto out; 1151 } 1152 l = path->nodes[0]; 1153 read_extent_buffer(l, &root->root_item, 1154 btrfs_item_ptr_offset(l, path->slots[0]), 1155 sizeof(root->root_item)); 1156 memcpy(&root->root_key, location, sizeof(*location)); 1157 ret = 0; 1158 out: 1159 btrfs_release_path(root, path); 1160 btrfs_free_path(path); 1161 if (ret) { 1162 kfree(root); 1163 return ERR_PTR(ret); 1164 } 1165 generation = btrfs_root_generation(&root->root_item); 1166 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); 1167 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), 1168 blocksize, generation); 1169 BUG_ON(!root->node); 1170 insert: 1171 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) { 1172 root->ref_cows = 1; 1173 ret = btrfs_find_highest_inode(root, &highest_inode); 1174 if (ret == 0) { 1175 root->highest_inode = highest_inode; 1176 root->last_inode_alloc = highest_inode; 1177 } 1178 } 1179 return root; 1180 } 1181 1182 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, 1183 u64 root_objectid) 1184 { 1185 struct btrfs_root *root; 1186 1187 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID) 1188 return fs_info->tree_root; 1189 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) 1190 return fs_info->extent_root; 1191 1192 root = radix_tree_lookup(&fs_info->fs_roots_radix, 1193 (unsigned long)root_objectid); 1194 return root; 1195 } 1196 1197 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, 1198 struct btrfs_key *location) 1199 { 1200 struct btrfs_root *root; 1201 int ret; 1202 1203 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) 1204 return fs_info->tree_root; 1205 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID) 1206 return fs_info->extent_root; 1207 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) 1208 return fs_info->chunk_root; 1209 if (location->objectid == BTRFS_DEV_TREE_OBJECTID) 1210 return fs_info->dev_root; 1211 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) 1212 return fs_info->csum_root; 1213 1214 root = radix_tree_lookup(&fs_info->fs_roots_radix, 1215 (unsigned long)location->objectid); 1216 if (root) 1217 return root; 1218 1219 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location); 1220 if (IS_ERR(root)) 1221 return root; 1222 1223 set_anon_super(&root->anon_super, NULL); 1224 1225 ret = radix_tree_insert(&fs_info->fs_roots_radix, 1226 (unsigned long)root->root_key.objectid, 1227 root); 1228 if (ret) { 1229 free_extent_buffer(root->node); 1230 kfree(root); 1231 return ERR_PTR(ret); 1232 } 1233 if (!(fs_info->sb->s_flags & MS_RDONLY)) { 1234 ret = btrfs_find_dead_roots(fs_info->tree_root, 1235 root->root_key.objectid, root); 1236 BUG_ON(ret); 1237 btrfs_orphan_cleanup(root); 1238 } 1239 return root; 1240 } 1241 1242 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, 1243 struct btrfs_key *location, 1244 const char *name, int namelen) 1245 { 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 #if 0 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 #endif 1271 root->in_sysfs = 1; 1272 return root; 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 #if 0 1282 if ((bdi_bits & (1 << BDI_write_congested)) && 1283 btrfs_congested_async(info, 0)) 1284 return 1; 1285 #endif 1286 list_for_each_entry(device, &info->fs_devices->devices, dev_list) { 1287 if (!device->bdev) 1288 continue; 1289 bdi = blk_get_backing_dev_info(device->bdev); 1290 if (bdi && bdi_congested(bdi, bdi_bits)) { 1291 ret = 1; 1292 break; 1293 } 1294 } 1295 return ret; 1296 } 1297 1298 /* 1299 * this unplugs every device on the box, and it is only used when page 1300 * is null 1301 */ 1302 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page) 1303 { 1304 struct btrfs_device *device; 1305 struct btrfs_fs_info *info; 1306 1307 info = (struct btrfs_fs_info *)bdi->unplug_io_data; 1308 list_for_each_entry(device, &info->fs_devices->devices, dev_list) { 1309 if (!device->bdev) 1310 continue; 1311 1312 bdi = blk_get_backing_dev_info(device->bdev); 1313 if (bdi->unplug_io_fn) 1314 bdi->unplug_io_fn(bdi, page); 1315 } 1316 } 1317 1318 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) 1319 { 1320 struct inode *inode; 1321 struct extent_map_tree *em_tree; 1322 struct extent_map *em; 1323 struct address_space *mapping; 1324 u64 offset; 1325 1326 /* the generic O_DIRECT read code does this */ 1327 if (1 || !page) { 1328 __unplug_io_fn(bdi, page); 1329 return; 1330 } 1331 1332 /* 1333 * page->mapping may change at any time. Get a consistent copy 1334 * and use that for everything below 1335 */ 1336 smp_mb(); 1337 mapping = page->mapping; 1338 if (!mapping) 1339 return; 1340 1341 inode = mapping->host; 1342 1343 /* 1344 * don't do the expensive searching for a small number of 1345 * devices 1346 */ 1347 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) { 1348 __unplug_io_fn(bdi, page); 1349 return; 1350 } 1351 1352 offset = page_offset(page); 1353 1354 em_tree = &BTRFS_I(inode)->extent_tree; 1355 spin_lock(&em_tree->lock); 1356 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE); 1357 spin_unlock(&em_tree->lock); 1358 if (!em) { 1359 __unplug_io_fn(bdi, page); 1360 return; 1361 } 1362 1363 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 1364 free_extent_map(em); 1365 __unplug_io_fn(bdi, page); 1366 return; 1367 } 1368 offset = offset - em->start; 1369 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree, 1370 em->block_start + offset, page); 1371 free_extent_map(em); 1372 } 1373 1374 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi) 1375 { 1376 bdi_init(bdi); 1377 bdi->ra_pages = default_backing_dev_info.ra_pages; 1378 bdi->state = 0; 1379 bdi->capabilities = default_backing_dev_info.capabilities; 1380 bdi->unplug_io_fn = btrfs_unplug_io_fn; 1381 bdi->unplug_io_data = info; 1382 bdi->congested_fn = btrfs_congested_fn; 1383 bdi->congested_data = info; 1384 return 0; 1385 } 1386 1387 static int bio_ready_for_csum(struct bio *bio) 1388 { 1389 u64 length = 0; 1390 u64 buf_len = 0; 1391 u64 start = 0; 1392 struct page *page; 1393 struct extent_io_tree *io_tree = NULL; 1394 struct btrfs_fs_info *info = NULL; 1395 struct bio_vec *bvec; 1396 int i; 1397 int ret; 1398 1399 bio_for_each_segment(bvec, bio, i) { 1400 page = bvec->bv_page; 1401 if (page->private == EXTENT_PAGE_PRIVATE) { 1402 length += bvec->bv_len; 1403 continue; 1404 } 1405 if (!page->private) { 1406 length += bvec->bv_len; 1407 continue; 1408 } 1409 length = bvec->bv_len; 1410 buf_len = page->private >> 2; 1411 start = page_offset(page) + bvec->bv_offset; 1412 io_tree = &BTRFS_I(page->mapping->host)->io_tree; 1413 info = BTRFS_I(page->mapping->host)->root->fs_info; 1414 } 1415 /* are we fully contained in this bio? */ 1416 if (buf_len <= length) 1417 return 1; 1418 1419 ret = extent_range_uptodate(io_tree, start + length, 1420 start + buf_len - 1); 1421 return ret; 1422 } 1423 1424 /* 1425 * called by the kthread helper functions to finally call the bio end_io 1426 * functions. This is where read checksum verification actually happens 1427 */ 1428 static void end_workqueue_fn(struct btrfs_work *work) 1429 { 1430 struct bio *bio; 1431 struct end_io_wq *end_io_wq; 1432 struct btrfs_fs_info *fs_info; 1433 int error; 1434 1435 end_io_wq = container_of(work, struct end_io_wq, work); 1436 bio = end_io_wq->bio; 1437 fs_info = end_io_wq->info; 1438 1439 /* metadata bio reads are special because the whole tree block must 1440 * be checksummed at once. This makes sure the entire block is in 1441 * ram and up to date before trying to verify things. For 1442 * blocksize <= pagesize, it is basically a noop 1443 */ 1444 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata && 1445 !bio_ready_for_csum(bio)) { 1446 btrfs_queue_worker(&fs_info->endio_meta_workers, 1447 &end_io_wq->work); 1448 return; 1449 } 1450 error = end_io_wq->error; 1451 bio->bi_private = end_io_wq->private; 1452 bio->bi_end_io = end_io_wq->end_io; 1453 kfree(end_io_wq); 1454 bio_endio(bio, error); 1455 } 1456 1457 static int cleaner_kthread(void *arg) 1458 { 1459 struct btrfs_root *root = arg; 1460 1461 do { 1462 smp_mb(); 1463 if (root->fs_info->closing) 1464 break; 1465 1466 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); 1467 mutex_lock(&root->fs_info->cleaner_mutex); 1468 btrfs_clean_old_snapshots(root); 1469 mutex_unlock(&root->fs_info->cleaner_mutex); 1470 1471 if (freezing(current)) { 1472 refrigerator(); 1473 } else { 1474 smp_mb(); 1475 if (root->fs_info->closing) 1476 break; 1477 set_current_state(TASK_INTERRUPTIBLE); 1478 schedule(); 1479 __set_current_state(TASK_RUNNING); 1480 } 1481 } while (!kthread_should_stop()); 1482 return 0; 1483 } 1484 1485 static int transaction_kthread(void *arg) 1486 { 1487 struct btrfs_root *root = arg; 1488 struct btrfs_trans_handle *trans; 1489 struct btrfs_transaction *cur; 1490 unsigned long now; 1491 unsigned long delay; 1492 int ret; 1493 1494 do { 1495 smp_mb(); 1496 if (root->fs_info->closing) 1497 break; 1498 1499 delay = HZ * 30; 1500 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); 1501 mutex_lock(&root->fs_info->transaction_kthread_mutex); 1502 1503 mutex_lock(&root->fs_info->trans_mutex); 1504 cur = root->fs_info->running_transaction; 1505 if (!cur) { 1506 mutex_unlock(&root->fs_info->trans_mutex); 1507 goto sleep; 1508 } 1509 1510 now = get_seconds(); 1511 if (now < cur->start_time || now - cur->start_time < 30) { 1512 mutex_unlock(&root->fs_info->trans_mutex); 1513 delay = HZ * 5; 1514 goto sleep; 1515 } 1516 mutex_unlock(&root->fs_info->trans_mutex); 1517 trans = btrfs_start_transaction(root, 1); 1518 ret = btrfs_commit_transaction(trans, root); 1519 1520 sleep: 1521 wake_up_process(root->fs_info->cleaner_kthread); 1522 mutex_unlock(&root->fs_info->transaction_kthread_mutex); 1523 1524 if (freezing(current)) { 1525 refrigerator(); 1526 } else { 1527 if (root->fs_info->closing) 1528 break; 1529 set_current_state(TASK_INTERRUPTIBLE); 1530 schedule_timeout(delay); 1531 __set_current_state(TASK_RUNNING); 1532 } 1533 } while (!kthread_should_stop()); 1534 return 0; 1535 } 1536 1537 struct btrfs_root *open_ctree(struct super_block *sb, 1538 struct btrfs_fs_devices *fs_devices, 1539 char *options) 1540 { 1541 u32 sectorsize; 1542 u32 nodesize; 1543 u32 leafsize; 1544 u32 blocksize; 1545 u32 stripesize; 1546 u64 generation; 1547 u64 features; 1548 struct btrfs_key location; 1549 struct buffer_head *bh; 1550 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root), 1551 GFP_NOFS); 1552 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root), 1553 GFP_NOFS); 1554 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root), 1555 GFP_NOFS); 1556 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info), 1557 GFP_NOFS); 1558 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root), 1559 GFP_NOFS); 1560 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root), 1561 GFP_NOFS); 1562 struct btrfs_root *log_tree_root; 1563 1564 int ret; 1565 int err = -EINVAL; 1566 1567 struct btrfs_super_block *disk_super; 1568 1569 if (!extent_root || !tree_root || !fs_info || 1570 !chunk_root || !dev_root || !csum_root) { 1571 err = -ENOMEM; 1572 goto fail; 1573 } 1574 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS); 1575 INIT_LIST_HEAD(&fs_info->trans_list); 1576 INIT_LIST_HEAD(&fs_info->dead_roots); 1577 INIT_LIST_HEAD(&fs_info->hashers); 1578 INIT_LIST_HEAD(&fs_info->delalloc_inodes); 1579 INIT_LIST_HEAD(&fs_info->ordered_operations); 1580 spin_lock_init(&fs_info->delalloc_lock); 1581 spin_lock_init(&fs_info->new_trans_lock); 1582 spin_lock_init(&fs_info->ref_cache_lock); 1583 1584 init_completion(&fs_info->kobj_unregister); 1585 fs_info->tree_root = tree_root; 1586 fs_info->extent_root = extent_root; 1587 fs_info->csum_root = csum_root; 1588 fs_info->chunk_root = chunk_root; 1589 fs_info->dev_root = dev_root; 1590 fs_info->fs_devices = fs_devices; 1591 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); 1592 INIT_LIST_HEAD(&fs_info->space_info); 1593 btrfs_mapping_init(&fs_info->mapping_tree); 1594 atomic_set(&fs_info->nr_async_submits, 0); 1595 atomic_set(&fs_info->async_delalloc_pages, 0); 1596 atomic_set(&fs_info->async_submit_draining, 0); 1597 atomic_set(&fs_info->nr_async_bios, 0); 1598 atomic_set(&fs_info->throttles, 0); 1599 atomic_set(&fs_info->throttle_gen, 0); 1600 fs_info->sb = sb; 1601 fs_info->max_extent = (u64)-1; 1602 fs_info->max_inline = 8192 * 1024; 1603 setup_bdi(fs_info, &fs_info->bdi); 1604 fs_info->btree_inode = new_inode(sb); 1605 fs_info->btree_inode->i_ino = 1; 1606 fs_info->btree_inode->i_nlink = 1; 1607 fs_info->metadata_ratio = 8; 1608 1609 fs_info->thread_pool_size = min_t(unsigned long, 1610 num_online_cpus() + 2, 8); 1611 1612 INIT_LIST_HEAD(&fs_info->ordered_extents); 1613 spin_lock_init(&fs_info->ordered_extent_lock); 1614 1615 sb->s_blocksize = 4096; 1616 sb->s_blocksize_bits = blksize_bits(4096); 1617 1618 /* 1619 * we set the i_size on the btree inode to the max possible int. 1620 * the real end of the address space is determined by all of 1621 * the devices in the system 1622 */ 1623 fs_info->btree_inode->i_size = OFFSET_MAX; 1624 fs_info->btree_inode->i_mapping->a_ops = &btree_aops; 1625 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi; 1626 1627 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree, 1628 fs_info->btree_inode->i_mapping, 1629 GFP_NOFS); 1630 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree, 1631 GFP_NOFS); 1632 1633 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops; 1634 1635 spin_lock_init(&fs_info->block_group_cache_lock); 1636 fs_info->block_group_cache_tree.rb_node = NULL; 1637 1638 extent_io_tree_init(&fs_info->pinned_extents, 1639 fs_info->btree_inode->i_mapping, GFP_NOFS); 1640 fs_info->do_barriers = 1; 1641 1642 INIT_LIST_HEAD(&fs_info->dead_reloc_roots); 1643 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree); 1644 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree); 1645 1646 BTRFS_I(fs_info->btree_inode)->root = tree_root; 1647 memset(&BTRFS_I(fs_info->btree_inode)->location, 0, 1648 sizeof(struct btrfs_key)); 1649 insert_inode_hash(fs_info->btree_inode); 1650 1651 mutex_init(&fs_info->trans_mutex); 1652 mutex_init(&fs_info->ordered_operations_mutex); 1653 mutex_init(&fs_info->tree_log_mutex); 1654 mutex_init(&fs_info->drop_mutex); 1655 mutex_init(&fs_info->chunk_mutex); 1656 mutex_init(&fs_info->transaction_kthread_mutex); 1657 mutex_init(&fs_info->cleaner_mutex); 1658 mutex_init(&fs_info->volume_mutex); 1659 mutex_init(&fs_info->tree_reloc_mutex); 1660 1661 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster); 1662 btrfs_init_free_cluster(&fs_info->data_alloc_cluster); 1663 1664 init_waitqueue_head(&fs_info->transaction_throttle); 1665 init_waitqueue_head(&fs_info->transaction_wait); 1666 init_waitqueue_head(&fs_info->async_submit_wait); 1667 1668 __setup_root(4096, 4096, 4096, 4096, tree_root, 1669 fs_info, BTRFS_ROOT_TREE_OBJECTID); 1670 1671 1672 bh = btrfs_read_dev_super(fs_devices->latest_bdev); 1673 if (!bh) 1674 goto fail_iput; 1675 1676 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy)); 1677 memcpy(&fs_info->super_for_commit, &fs_info->super_copy, 1678 sizeof(fs_info->super_for_commit)); 1679 brelse(bh); 1680 1681 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE); 1682 1683 disk_super = &fs_info->super_copy; 1684 if (!btrfs_super_root(disk_super)) 1685 goto fail_iput; 1686 1687 ret = btrfs_parse_options(tree_root, options); 1688 if (ret) { 1689 err = ret; 1690 goto fail_iput; 1691 } 1692 1693 features = btrfs_super_incompat_flags(disk_super) & 1694 ~BTRFS_FEATURE_INCOMPAT_SUPP; 1695 if (features) { 1696 printk(KERN_ERR "BTRFS: couldn't mount because of " 1697 "unsupported optional features (%Lx).\n", 1698 features); 1699 err = -EINVAL; 1700 goto fail_iput; 1701 } 1702 1703 features = btrfs_super_compat_ro_flags(disk_super) & 1704 ~BTRFS_FEATURE_COMPAT_RO_SUPP; 1705 if (!(sb->s_flags & MS_RDONLY) && features) { 1706 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of " 1707 "unsupported option features (%Lx).\n", 1708 features); 1709 err = -EINVAL; 1710 goto fail_iput; 1711 } 1712 1713 /* 1714 * we need to start all the end_io workers up front because the 1715 * queue work function gets called at interrupt time, and so it 1716 * cannot dynamically grow. 1717 */ 1718 btrfs_init_workers(&fs_info->workers, "worker", 1719 fs_info->thread_pool_size); 1720 1721 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc", 1722 fs_info->thread_pool_size); 1723 1724 btrfs_init_workers(&fs_info->submit_workers, "submit", 1725 min_t(u64, fs_devices->num_devices, 1726 fs_info->thread_pool_size)); 1727 1728 /* a higher idle thresh on the submit workers makes it much more 1729 * likely that bios will be send down in a sane order to the 1730 * devices 1731 */ 1732 fs_info->submit_workers.idle_thresh = 64; 1733 1734 fs_info->workers.idle_thresh = 16; 1735 fs_info->workers.ordered = 1; 1736 1737 fs_info->delalloc_workers.idle_thresh = 2; 1738 fs_info->delalloc_workers.ordered = 1; 1739 1740 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1); 1741 btrfs_init_workers(&fs_info->endio_workers, "endio", 1742 fs_info->thread_pool_size); 1743 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta", 1744 fs_info->thread_pool_size); 1745 btrfs_init_workers(&fs_info->endio_meta_write_workers, 1746 "endio-meta-write", fs_info->thread_pool_size); 1747 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write", 1748 fs_info->thread_pool_size); 1749 1750 /* 1751 * endios are largely parallel and should have a very 1752 * low idle thresh 1753 */ 1754 fs_info->endio_workers.idle_thresh = 4; 1755 fs_info->endio_meta_workers.idle_thresh = 4; 1756 1757 fs_info->endio_write_workers.idle_thresh = 64; 1758 fs_info->endio_meta_write_workers.idle_thresh = 64; 1759 1760 btrfs_start_workers(&fs_info->workers, 1); 1761 btrfs_start_workers(&fs_info->submit_workers, 1); 1762 btrfs_start_workers(&fs_info->delalloc_workers, 1); 1763 btrfs_start_workers(&fs_info->fixup_workers, 1); 1764 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size); 1765 btrfs_start_workers(&fs_info->endio_meta_workers, 1766 fs_info->thread_pool_size); 1767 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1768 fs_info->thread_pool_size); 1769 btrfs_start_workers(&fs_info->endio_write_workers, 1770 fs_info->thread_pool_size); 1771 1772 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super); 1773 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages, 1774 4 * 1024 * 1024 / PAGE_CACHE_SIZE); 1775 1776 nodesize = btrfs_super_nodesize(disk_super); 1777 leafsize = btrfs_super_leafsize(disk_super); 1778 sectorsize = btrfs_super_sectorsize(disk_super); 1779 stripesize = btrfs_super_stripesize(disk_super); 1780 tree_root->nodesize = nodesize; 1781 tree_root->leafsize = leafsize; 1782 tree_root->sectorsize = sectorsize; 1783 tree_root->stripesize = stripesize; 1784 1785 sb->s_blocksize = sectorsize; 1786 sb->s_blocksize_bits = blksize_bits(sectorsize); 1787 1788 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, 1789 sizeof(disk_super->magic))) { 1790 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id); 1791 goto fail_sb_buffer; 1792 } 1793 1794 mutex_lock(&fs_info->chunk_mutex); 1795 ret = btrfs_read_sys_array(tree_root); 1796 mutex_unlock(&fs_info->chunk_mutex); 1797 if (ret) { 1798 printk(KERN_WARNING "btrfs: failed to read the system " 1799 "array on %s\n", sb->s_id); 1800 goto fail_sys_array; 1801 } 1802 1803 blocksize = btrfs_level_size(tree_root, 1804 btrfs_super_chunk_root_level(disk_super)); 1805 generation = btrfs_super_chunk_root_generation(disk_super); 1806 1807 __setup_root(nodesize, leafsize, sectorsize, stripesize, 1808 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID); 1809 1810 chunk_root->node = read_tree_block(chunk_root, 1811 btrfs_super_chunk_root(disk_super), 1812 blocksize, generation); 1813 BUG_ON(!chunk_root->node); 1814 1815 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid, 1816 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node), 1817 BTRFS_UUID_SIZE); 1818 1819 mutex_lock(&fs_info->chunk_mutex); 1820 ret = btrfs_read_chunk_tree(chunk_root); 1821 mutex_unlock(&fs_info->chunk_mutex); 1822 if (ret) { 1823 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n", 1824 sb->s_id); 1825 goto fail_chunk_root; 1826 } 1827 1828 btrfs_close_extra_devices(fs_devices); 1829 1830 blocksize = btrfs_level_size(tree_root, 1831 btrfs_super_root_level(disk_super)); 1832 generation = btrfs_super_generation(disk_super); 1833 1834 tree_root->node = read_tree_block(tree_root, 1835 btrfs_super_root(disk_super), 1836 blocksize, generation); 1837 if (!tree_root->node) 1838 goto fail_chunk_root; 1839 1840 1841 ret = find_and_setup_root(tree_root, fs_info, 1842 BTRFS_EXTENT_TREE_OBJECTID, extent_root); 1843 if (ret) 1844 goto fail_tree_root; 1845 extent_root->track_dirty = 1; 1846 1847 ret = find_and_setup_root(tree_root, fs_info, 1848 BTRFS_DEV_TREE_OBJECTID, dev_root); 1849 dev_root->track_dirty = 1; 1850 if (ret) 1851 goto fail_extent_root; 1852 1853 ret = find_and_setup_root(tree_root, fs_info, 1854 BTRFS_CSUM_TREE_OBJECTID, csum_root); 1855 if (ret) 1856 goto fail_extent_root; 1857 1858 csum_root->track_dirty = 1; 1859 1860 btrfs_read_block_groups(extent_root); 1861 1862 fs_info->generation = generation; 1863 fs_info->last_trans_committed = generation; 1864 fs_info->data_alloc_profile = (u64)-1; 1865 fs_info->metadata_alloc_profile = (u64)-1; 1866 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile; 1867 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root, 1868 "btrfs-cleaner"); 1869 if (IS_ERR(fs_info->cleaner_kthread)) 1870 goto fail_csum_root; 1871 1872 fs_info->transaction_kthread = kthread_run(transaction_kthread, 1873 tree_root, 1874 "btrfs-transaction"); 1875 if (IS_ERR(fs_info->transaction_kthread)) 1876 goto fail_cleaner; 1877 1878 if (btrfs_super_log_root(disk_super) != 0) { 1879 u64 bytenr = btrfs_super_log_root(disk_super); 1880 1881 if (fs_devices->rw_devices == 0) { 1882 printk(KERN_WARNING "Btrfs log replay required " 1883 "on RO media\n"); 1884 err = -EIO; 1885 goto fail_trans_kthread; 1886 } 1887 blocksize = 1888 btrfs_level_size(tree_root, 1889 btrfs_super_log_root_level(disk_super)); 1890 1891 log_tree_root = kzalloc(sizeof(struct btrfs_root), 1892 GFP_NOFS); 1893 1894 __setup_root(nodesize, leafsize, sectorsize, stripesize, 1895 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID); 1896 1897 log_tree_root->node = read_tree_block(tree_root, bytenr, 1898 blocksize, 1899 generation + 1); 1900 ret = btrfs_recover_log_trees(log_tree_root); 1901 BUG_ON(ret); 1902 1903 if (sb->s_flags & MS_RDONLY) { 1904 ret = btrfs_commit_super(tree_root); 1905 BUG_ON(ret); 1906 } 1907 } 1908 1909 if (!(sb->s_flags & MS_RDONLY)) { 1910 ret = btrfs_cleanup_reloc_trees(tree_root); 1911 BUG_ON(ret); 1912 } 1913 1914 location.objectid = BTRFS_FS_TREE_OBJECTID; 1915 location.type = BTRFS_ROOT_ITEM_KEY; 1916 location.offset = (u64)-1; 1917 1918 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location); 1919 if (!fs_info->fs_root) 1920 goto fail_trans_kthread; 1921 return tree_root; 1922 1923 fail_trans_kthread: 1924 kthread_stop(fs_info->transaction_kthread); 1925 fail_cleaner: 1926 kthread_stop(fs_info->cleaner_kthread); 1927 1928 /* 1929 * make sure we're done with the btree inode before we stop our 1930 * kthreads 1931 */ 1932 filemap_write_and_wait(fs_info->btree_inode->i_mapping); 1933 invalidate_inode_pages2(fs_info->btree_inode->i_mapping); 1934 1935 fail_csum_root: 1936 free_extent_buffer(csum_root->node); 1937 fail_extent_root: 1938 free_extent_buffer(extent_root->node); 1939 fail_tree_root: 1940 free_extent_buffer(tree_root->node); 1941 fail_chunk_root: 1942 free_extent_buffer(chunk_root->node); 1943 fail_sys_array: 1944 free_extent_buffer(dev_root->node); 1945 fail_sb_buffer: 1946 btrfs_stop_workers(&fs_info->fixup_workers); 1947 btrfs_stop_workers(&fs_info->delalloc_workers); 1948 btrfs_stop_workers(&fs_info->workers); 1949 btrfs_stop_workers(&fs_info->endio_workers); 1950 btrfs_stop_workers(&fs_info->endio_meta_workers); 1951 btrfs_stop_workers(&fs_info->endio_meta_write_workers); 1952 btrfs_stop_workers(&fs_info->endio_write_workers); 1953 btrfs_stop_workers(&fs_info->submit_workers); 1954 fail_iput: 1955 invalidate_inode_pages2(fs_info->btree_inode->i_mapping); 1956 iput(fs_info->btree_inode); 1957 1958 btrfs_close_devices(fs_info->fs_devices); 1959 btrfs_mapping_tree_free(&fs_info->mapping_tree); 1960 bdi_destroy(&fs_info->bdi); 1961 1962 fail: 1963 kfree(extent_root); 1964 kfree(tree_root); 1965 kfree(fs_info); 1966 kfree(chunk_root); 1967 kfree(dev_root); 1968 kfree(csum_root); 1969 return ERR_PTR(err); 1970 } 1971 1972 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) 1973 { 1974 char b[BDEVNAME_SIZE]; 1975 1976 if (uptodate) { 1977 set_buffer_uptodate(bh); 1978 } else { 1979 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) { 1980 printk(KERN_WARNING "lost page write due to " 1981 "I/O error on %s\n", 1982 bdevname(bh->b_bdev, b)); 1983 } 1984 /* note, we dont' set_buffer_write_io_error because we have 1985 * our own ways of dealing with the IO errors 1986 */ 1987 clear_buffer_uptodate(bh); 1988 } 1989 unlock_buffer(bh); 1990 put_bh(bh); 1991 } 1992 1993 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev) 1994 { 1995 struct buffer_head *bh; 1996 struct buffer_head *latest = NULL; 1997 struct btrfs_super_block *super; 1998 int i; 1999 u64 transid = 0; 2000 u64 bytenr; 2001 2002 /* we would like to check all the supers, but that would make 2003 * a btrfs mount succeed after a mkfs from a different FS. 2004 * So, we need to add a special mount option to scan for 2005 * later supers, using BTRFS_SUPER_MIRROR_MAX instead 2006 */ 2007 for (i = 0; i < 1; i++) { 2008 bytenr = btrfs_sb_offset(i); 2009 if (bytenr + 4096 >= i_size_read(bdev->bd_inode)) 2010 break; 2011 bh = __bread(bdev, bytenr / 4096, 4096); 2012 if (!bh) 2013 continue; 2014 2015 super = (struct btrfs_super_block *)bh->b_data; 2016 if (btrfs_super_bytenr(super) != bytenr || 2017 strncmp((char *)(&super->magic), BTRFS_MAGIC, 2018 sizeof(super->magic))) { 2019 brelse(bh); 2020 continue; 2021 } 2022 2023 if (!latest || btrfs_super_generation(super) > transid) { 2024 brelse(latest); 2025 latest = bh; 2026 transid = btrfs_super_generation(super); 2027 } else { 2028 brelse(bh); 2029 } 2030 } 2031 return latest; 2032 } 2033 2034 static int write_dev_supers(struct btrfs_device *device, 2035 struct btrfs_super_block *sb, 2036 int do_barriers, int wait, int max_mirrors) 2037 { 2038 struct buffer_head *bh; 2039 int i; 2040 int ret; 2041 int errors = 0; 2042 u32 crc; 2043 u64 bytenr; 2044 int last_barrier = 0; 2045 2046 if (max_mirrors == 0) 2047 max_mirrors = BTRFS_SUPER_MIRROR_MAX; 2048 2049 /* make sure only the last submit_bh does a barrier */ 2050 if (do_barriers) { 2051 for (i = 0; i < max_mirrors; i++) { 2052 bytenr = btrfs_sb_offset(i); 2053 if (bytenr + BTRFS_SUPER_INFO_SIZE >= 2054 device->total_bytes) 2055 break; 2056 last_barrier = i; 2057 } 2058 } 2059 2060 for (i = 0; i < max_mirrors; i++) { 2061 bytenr = btrfs_sb_offset(i); 2062 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes) 2063 break; 2064 2065 if (wait) { 2066 bh = __find_get_block(device->bdev, bytenr / 4096, 2067 BTRFS_SUPER_INFO_SIZE); 2068 BUG_ON(!bh); 2069 brelse(bh); 2070 wait_on_buffer(bh); 2071 if (buffer_uptodate(bh)) { 2072 brelse(bh); 2073 continue; 2074 } 2075 } else { 2076 btrfs_set_super_bytenr(sb, bytenr); 2077 2078 crc = ~(u32)0; 2079 crc = btrfs_csum_data(NULL, (char *)sb + 2080 BTRFS_CSUM_SIZE, crc, 2081 BTRFS_SUPER_INFO_SIZE - 2082 BTRFS_CSUM_SIZE); 2083 btrfs_csum_final(crc, sb->csum); 2084 2085 bh = __getblk(device->bdev, bytenr / 4096, 2086 BTRFS_SUPER_INFO_SIZE); 2087 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE); 2088 2089 set_buffer_uptodate(bh); 2090 get_bh(bh); 2091 lock_buffer(bh); 2092 bh->b_end_io = btrfs_end_buffer_write_sync; 2093 } 2094 2095 if (i == last_barrier && do_barriers && device->barriers) { 2096 ret = submit_bh(WRITE_BARRIER, bh); 2097 if (ret == -EOPNOTSUPP) { 2098 printk("btrfs: disabling barriers on dev %s\n", 2099 device->name); 2100 set_buffer_uptodate(bh); 2101 device->barriers = 0; 2102 get_bh(bh); 2103 lock_buffer(bh); 2104 ret = submit_bh(WRITE_SYNC, bh); 2105 } 2106 } else { 2107 ret = submit_bh(WRITE_SYNC, bh); 2108 } 2109 2110 if (!ret && wait) { 2111 wait_on_buffer(bh); 2112 if (!buffer_uptodate(bh)) 2113 errors++; 2114 } else if (ret) { 2115 errors++; 2116 } 2117 if (wait) 2118 brelse(bh); 2119 } 2120 return errors < i ? 0 : -1; 2121 } 2122 2123 int write_all_supers(struct btrfs_root *root, int max_mirrors) 2124 { 2125 struct list_head *head = &root->fs_info->fs_devices->devices; 2126 struct btrfs_device *dev; 2127 struct btrfs_super_block *sb; 2128 struct btrfs_dev_item *dev_item; 2129 int ret; 2130 int do_barriers; 2131 int max_errors; 2132 int total_errors = 0; 2133 u64 flags; 2134 2135 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1; 2136 do_barriers = !btrfs_test_opt(root, NOBARRIER); 2137 2138 sb = &root->fs_info->super_for_commit; 2139 dev_item = &sb->dev_item; 2140 list_for_each_entry(dev, head, dev_list) { 2141 if (!dev->bdev) { 2142 total_errors++; 2143 continue; 2144 } 2145 if (!dev->in_fs_metadata || !dev->writeable) 2146 continue; 2147 2148 btrfs_set_stack_device_generation(dev_item, 0); 2149 btrfs_set_stack_device_type(dev_item, dev->type); 2150 btrfs_set_stack_device_id(dev_item, dev->devid); 2151 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes); 2152 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used); 2153 btrfs_set_stack_device_io_align(dev_item, dev->io_align); 2154 btrfs_set_stack_device_io_width(dev_item, dev->io_width); 2155 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size); 2156 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE); 2157 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE); 2158 2159 flags = btrfs_super_flags(sb); 2160 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN); 2161 2162 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors); 2163 if (ret) 2164 total_errors++; 2165 } 2166 if (total_errors > max_errors) { 2167 printk(KERN_ERR "btrfs: %d errors while writing supers\n", 2168 total_errors); 2169 BUG(); 2170 } 2171 2172 total_errors = 0; 2173 list_for_each_entry(dev, head, dev_list) { 2174 if (!dev->bdev) 2175 continue; 2176 if (!dev->in_fs_metadata || !dev->writeable) 2177 continue; 2178 2179 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors); 2180 if (ret) 2181 total_errors++; 2182 } 2183 if (total_errors > max_errors) { 2184 printk(KERN_ERR "btrfs: %d errors while writing supers\n", 2185 total_errors); 2186 BUG(); 2187 } 2188 return 0; 2189 } 2190 2191 int write_ctree_super(struct btrfs_trans_handle *trans, 2192 struct btrfs_root *root, int max_mirrors) 2193 { 2194 int ret; 2195 2196 ret = write_all_supers(root, max_mirrors); 2197 return ret; 2198 } 2199 2200 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) 2201 { 2202 radix_tree_delete(&fs_info->fs_roots_radix, 2203 (unsigned long)root->root_key.objectid); 2204 if (root->anon_super.s_dev) { 2205 down_write(&root->anon_super.s_umount); 2206 kill_anon_super(&root->anon_super); 2207 } 2208 if (root->node) 2209 free_extent_buffer(root->node); 2210 if (root->commit_root) 2211 free_extent_buffer(root->commit_root); 2212 kfree(root->name); 2213 kfree(root); 2214 return 0; 2215 } 2216 2217 static int del_fs_roots(struct btrfs_fs_info *fs_info) 2218 { 2219 int ret; 2220 struct btrfs_root *gang[8]; 2221 int i; 2222 2223 while (1) { 2224 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix, 2225 (void **)gang, 0, 2226 ARRAY_SIZE(gang)); 2227 if (!ret) 2228 break; 2229 for (i = 0; i < ret; i++) 2230 btrfs_free_fs_root(fs_info, gang[i]); 2231 } 2232 return 0; 2233 } 2234 2235 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info) 2236 { 2237 u64 root_objectid = 0; 2238 struct btrfs_root *gang[8]; 2239 int i; 2240 int ret; 2241 2242 while (1) { 2243 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix, 2244 (void **)gang, root_objectid, 2245 ARRAY_SIZE(gang)); 2246 if (!ret) 2247 break; 2248 for (i = 0; i < ret; i++) { 2249 root_objectid = gang[i]->root_key.objectid; 2250 ret = btrfs_find_dead_roots(fs_info->tree_root, 2251 root_objectid, gang[i]); 2252 BUG_ON(ret); 2253 btrfs_orphan_cleanup(gang[i]); 2254 } 2255 root_objectid++; 2256 } 2257 return 0; 2258 } 2259 2260 int btrfs_commit_super(struct btrfs_root *root) 2261 { 2262 struct btrfs_trans_handle *trans; 2263 int ret; 2264 2265 mutex_lock(&root->fs_info->cleaner_mutex); 2266 btrfs_clean_old_snapshots(root); 2267 mutex_unlock(&root->fs_info->cleaner_mutex); 2268 trans = btrfs_start_transaction(root, 1); 2269 ret = btrfs_commit_transaction(trans, root); 2270 BUG_ON(ret); 2271 /* run commit again to drop the original snapshot */ 2272 trans = btrfs_start_transaction(root, 1); 2273 btrfs_commit_transaction(trans, root); 2274 ret = btrfs_write_and_wait_transaction(NULL, root); 2275 BUG_ON(ret); 2276 2277 ret = write_ctree_super(NULL, root, 0); 2278 return ret; 2279 } 2280 2281 int close_ctree(struct btrfs_root *root) 2282 { 2283 struct btrfs_fs_info *fs_info = root->fs_info; 2284 int ret; 2285 2286 fs_info->closing = 1; 2287 smp_mb(); 2288 2289 kthread_stop(root->fs_info->transaction_kthread); 2290 kthread_stop(root->fs_info->cleaner_kthread); 2291 2292 if (!(fs_info->sb->s_flags & MS_RDONLY)) { 2293 ret = btrfs_commit_super(root); 2294 if (ret) 2295 printk(KERN_ERR "btrfs: commit super ret %d\n", ret); 2296 } 2297 2298 if (fs_info->delalloc_bytes) { 2299 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n", 2300 fs_info->delalloc_bytes); 2301 } 2302 if (fs_info->total_ref_cache_size) { 2303 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n", 2304 (unsigned long long)fs_info->total_ref_cache_size); 2305 } 2306 2307 if (fs_info->extent_root->node) 2308 free_extent_buffer(fs_info->extent_root->node); 2309 2310 if (fs_info->tree_root->node) 2311 free_extent_buffer(fs_info->tree_root->node); 2312 2313 if (root->fs_info->chunk_root->node) 2314 free_extent_buffer(root->fs_info->chunk_root->node); 2315 2316 if (root->fs_info->dev_root->node) 2317 free_extent_buffer(root->fs_info->dev_root->node); 2318 2319 if (root->fs_info->csum_root->node) 2320 free_extent_buffer(root->fs_info->csum_root->node); 2321 2322 btrfs_free_block_groups(root->fs_info); 2323 2324 del_fs_roots(fs_info); 2325 2326 iput(fs_info->btree_inode); 2327 2328 btrfs_stop_workers(&fs_info->fixup_workers); 2329 btrfs_stop_workers(&fs_info->delalloc_workers); 2330 btrfs_stop_workers(&fs_info->workers); 2331 btrfs_stop_workers(&fs_info->endio_workers); 2332 btrfs_stop_workers(&fs_info->endio_meta_workers); 2333 btrfs_stop_workers(&fs_info->endio_meta_write_workers); 2334 btrfs_stop_workers(&fs_info->endio_write_workers); 2335 btrfs_stop_workers(&fs_info->submit_workers); 2336 2337 #if 0 2338 while (!list_empty(&fs_info->hashers)) { 2339 struct btrfs_hasher *hasher; 2340 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher, 2341 hashers); 2342 list_del(&hasher->hashers); 2343 crypto_free_hash(&fs_info->hash_tfm); 2344 kfree(hasher); 2345 } 2346 #endif 2347 btrfs_close_devices(fs_info->fs_devices); 2348 btrfs_mapping_tree_free(&fs_info->mapping_tree); 2349 2350 bdi_destroy(&fs_info->bdi); 2351 2352 kfree(fs_info->extent_root); 2353 kfree(fs_info->tree_root); 2354 kfree(fs_info->chunk_root); 2355 kfree(fs_info->dev_root); 2356 kfree(fs_info->csum_root); 2357 return 0; 2358 } 2359 2360 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid) 2361 { 2362 int ret; 2363 struct inode *btree_inode = buf->first_page->mapping->host; 2364 2365 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf); 2366 if (!ret) 2367 return ret; 2368 2369 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf, 2370 parent_transid); 2371 return !ret; 2372 } 2373 2374 int btrfs_set_buffer_uptodate(struct extent_buffer *buf) 2375 { 2376 struct inode *btree_inode = buf->first_page->mapping->host; 2377 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, 2378 buf); 2379 } 2380 2381 void btrfs_mark_buffer_dirty(struct extent_buffer *buf) 2382 { 2383 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; 2384 u64 transid = btrfs_header_generation(buf); 2385 struct inode *btree_inode = root->fs_info->btree_inode; 2386 int was_dirty; 2387 2388 btrfs_assert_tree_locked(buf); 2389 if (transid != root->fs_info->generation) { 2390 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, " 2391 "found %llu running %llu\n", 2392 (unsigned long long)buf->start, 2393 (unsigned long long)transid, 2394 (unsigned long long)root->fs_info->generation); 2395 WARN_ON(1); 2396 } 2397 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, 2398 buf); 2399 if (!was_dirty) { 2400 spin_lock(&root->fs_info->delalloc_lock); 2401 root->fs_info->dirty_metadata_bytes += buf->len; 2402 spin_unlock(&root->fs_info->delalloc_lock); 2403 } 2404 } 2405 2406 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr) 2407 { 2408 /* 2409 * looks as though older kernels can get into trouble with 2410 * this code, they end up stuck in balance_dirty_pages forever 2411 */ 2412 struct extent_io_tree *tree; 2413 u64 num_dirty; 2414 u64 start = 0; 2415 unsigned long thresh = 32 * 1024 * 1024; 2416 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree; 2417 2418 if (current->flags & PF_MEMALLOC) 2419 return; 2420 2421 num_dirty = count_range_bits(tree, &start, (u64)-1, 2422 thresh, EXTENT_DIRTY); 2423 if (num_dirty > thresh) { 2424 balance_dirty_pages_ratelimited_nr( 2425 root->fs_info->btree_inode->i_mapping, 1); 2426 } 2427 return; 2428 } 2429 2430 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid) 2431 { 2432 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; 2433 int ret; 2434 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); 2435 if (ret == 0) 2436 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); 2437 return ret; 2438 } 2439 2440 int btree_lock_page_hook(struct page *page) 2441 { 2442 struct inode *inode = page->mapping->host; 2443 struct btrfs_root *root = BTRFS_I(inode)->root; 2444 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2445 struct extent_buffer *eb; 2446 unsigned long len; 2447 u64 bytenr = page_offset(page); 2448 2449 if (page->private == EXTENT_PAGE_PRIVATE) 2450 goto out; 2451 2452 len = page->private >> 2; 2453 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS); 2454 if (!eb) 2455 goto out; 2456 2457 btrfs_tree_lock(eb); 2458 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); 2459 2460 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { 2461 spin_lock(&root->fs_info->delalloc_lock); 2462 if (root->fs_info->dirty_metadata_bytes >= eb->len) 2463 root->fs_info->dirty_metadata_bytes -= eb->len; 2464 else 2465 WARN_ON(1); 2466 spin_unlock(&root->fs_info->delalloc_lock); 2467 } 2468 2469 btrfs_tree_unlock(eb); 2470 free_extent_buffer(eb); 2471 out: 2472 lock_page(page); 2473 return 0; 2474 } 2475 2476 static struct extent_io_ops btree_extent_io_ops = { 2477 .write_cache_pages_lock_hook = btree_lock_page_hook, 2478 .readpage_end_io_hook = btree_readpage_end_io_hook, 2479 .submit_bio_hook = btree_submit_bio_hook, 2480 /* note we're sharing with inode.c for the merge bio hook */ 2481 .merge_bio_hook = btrfs_merge_bio_hook, 2482 }; 2483