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btrfs: state information for readahead
[deliverable/linux.git] / fs / btrfs / disk-io.c
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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 <linux/migrate.h>
32#include <linux/ratelimit.h>
33#include <asm/unaligned.h>
34#include "compat.h"
35#include "ctree.h"
36#include "disk-io.h"
37#include "transaction.h"
38#include "btrfs_inode.h"
39#include "volumes.h"
40#include "print-tree.h"
41#include "async-thread.h"
42#include "locking.h"
43#include "tree-log.h"
44#include "free-space-cache.h"
45#include "inode-map.h"
46
47static struct extent_io_ops btree_extent_io_ops;
48static void end_workqueue_fn(struct btrfs_work *work);
49static void free_fs_root(struct btrfs_root *root);
50static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
51 int read_only);
52static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
53static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
54static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
55 struct btrfs_root *root);
56static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
57static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
58static int btrfs_destroy_marked_extents(struct btrfs_root *root,
59 struct extent_io_tree *dirty_pages,
60 int mark);
61static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
62 struct extent_io_tree *pinned_extents);
63static int btrfs_cleanup_transaction(struct btrfs_root *root);
64
65/*
66 * end_io_wq structs are used to do processing in task context when an IO is
67 * complete. This is used during reads to verify checksums, and it is used
68 * by writes to insert metadata for new file extents after IO is complete.
69 */
70struct end_io_wq {
71 struct bio *bio;
72 bio_end_io_t *end_io;
73 void *private;
74 struct btrfs_fs_info *info;
75 int error;
76 int metadata;
77 struct list_head list;
78 struct btrfs_work work;
79};
80
81/*
82 * async submit bios are used to offload expensive checksumming
83 * onto the worker threads. They checksum file and metadata bios
84 * just before they are sent down the IO stack.
85 */
86struct async_submit_bio {
87 struct inode *inode;
88 struct bio *bio;
89 struct list_head list;
90 extent_submit_bio_hook_t *submit_bio_start;
91 extent_submit_bio_hook_t *submit_bio_done;
92 int rw;
93 int mirror_num;
94 unsigned long bio_flags;
95 /*
96 * bio_offset is optional, can be used if the pages in the bio
97 * can't tell us where in the file the bio should go
98 */
99 u64 bio_offset;
100 struct btrfs_work work;
101};
102
103/*
104 * Lockdep class keys for extent_buffer->lock's in this root. For a given
105 * eb, the lockdep key is determined by the btrfs_root it belongs to and
106 * the level the eb occupies in the tree.
107 *
108 * Different roots are used for different purposes and may nest inside each
109 * other and they require separate keysets. As lockdep keys should be
110 * static, assign keysets according to the purpose of the root as indicated
111 * by btrfs_root->objectid. This ensures that all special purpose roots
112 * have separate keysets.
113 *
114 * Lock-nesting across peer nodes is always done with the immediate parent
115 * node locked thus preventing deadlock. As lockdep doesn't know this, use
116 * subclass to avoid triggering lockdep warning in such cases.
117 *
118 * The key is set by the readpage_end_io_hook after the buffer has passed
119 * csum validation but before the pages are unlocked. It is also set by
120 * btrfs_init_new_buffer on freshly allocated blocks.
121 *
122 * We also add a check to make sure the highest level of the tree is the
123 * same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this code
124 * needs update as well.
125 */
126#ifdef CONFIG_DEBUG_LOCK_ALLOC
127# if BTRFS_MAX_LEVEL != 8
128# error
129# endif
130
131static struct btrfs_lockdep_keyset {
132 u64 id; /* root objectid */
133 const char *name_stem; /* lock name stem */
134 char names[BTRFS_MAX_LEVEL + 1][20];
135 struct lock_class_key keys[BTRFS_MAX_LEVEL + 1];
136} btrfs_lockdep_keysets[] = {
137 { .id = BTRFS_ROOT_TREE_OBJECTID, .name_stem = "root" },
138 { .id = BTRFS_EXTENT_TREE_OBJECTID, .name_stem = "extent" },
139 { .id = BTRFS_CHUNK_TREE_OBJECTID, .name_stem = "chunk" },
140 { .id = BTRFS_DEV_TREE_OBJECTID, .name_stem = "dev" },
141 { .id = BTRFS_FS_TREE_OBJECTID, .name_stem = "fs" },
142 { .id = BTRFS_CSUM_TREE_OBJECTID, .name_stem = "csum" },
143 { .id = BTRFS_ORPHAN_OBJECTID, .name_stem = "orphan" },
144 { .id = BTRFS_TREE_LOG_OBJECTID, .name_stem = "log" },
145 { .id = BTRFS_TREE_RELOC_OBJECTID, .name_stem = "treloc" },
146 { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc" },
147 { .id = 0, .name_stem = "tree" },
148};
149
150void __init btrfs_init_lockdep(void)
151{
152 int i, j;
153
154 /* initialize lockdep class names */
155 for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
156 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
157
158 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
159 snprintf(ks->names[j], sizeof(ks->names[j]),
160 "btrfs-%s-%02d", ks->name_stem, j);
161 }
162}
163
164void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
165 int level)
166{
167 struct btrfs_lockdep_keyset *ks;
168
169 BUG_ON(level >= ARRAY_SIZE(ks->keys));
170
171 /* find the matching keyset, id 0 is the default entry */
172 for (ks = btrfs_lockdep_keysets; ks->id; ks++)
173 if (ks->id == objectid)
174 break;
175
176 lockdep_set_class_and_name(&eb->lock,
177 &ks->keys[level], ks->names[level]);
178}
179
180#endif
181
182/*
183 * extents on the btree inode are pretty simple, there's one extent
184 * that covers the entire device
185 */
186static struct extent_map *btree_get_extent(struct inode *inode,
187 struct page *page, size_t pg_offset, u64 start, u64 len,
188 int create)
189{
190 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
191 struct extent_map *em;
192 int ret;
193
194 read_lock(&em_tree->lock);
195 em = lookup_extent_mapping(em_tree, start, len);
196 if (em) {
197 em->bdev =
198 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
199 read_unlock(&em_tree->lock);
200 goto out;
201 }
202 read_unlock(&em_tree->lock);
203
204 em = alloc_extent_map();
205 if (!em) {
206 em = ERR_PTR(-ENOMEM);
207 goto out;
208 }
209 em->start = 0;
210 em->len = (u64)-1;
211 em->block_len = (u64)-1;
212 em->block_start = 0;
213 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
214
215 write_lock(&em_tree->lock);
216 ret = add_extent_mapping(em_tree, em);
217 if (ret == -EEXIST) {
218 u64 failed_start = em->start;
219 u64 failed_len = em->len;
220
221 free_extent_map(em);
222 em = lookup_extent_mapping(em_tree, start, len);
223 if (em) {
224 ret = 0;
225 } else {
226 em = lookup_extent_mapping(em_tree, failed_start,
227 failed_len);
228 ret = -EIO;
229 }
230 } else if (ret) {
231 free_extent_map(em);
232 em = NULL;
233 }
234 write_unlock(&em_tree->lock);
235
236 if (ret)
237 em = ERR_PTR(ret);
238out:
239 return em;
240}
241
242u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
243{
244 return crc32c(seed, data, len);
245}
246
247void btrfs_csum_final(u32 crc, char *result)
248{
249 put_unaligned_le32(~crc, result);
250}
251
252/*
253 * compute the csum for a btree block, and either verify it or write it
254 * into the csum field of the block.
255 */
256static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
257 int verify)
258{
259 u16 csum_size =
260 btrfs_super_csum_size(&root->fs_info->super_copy);
261 char *result = NULL;
262 unsigned long len;
263 unsigned long cur_len;
264 unsigned long offset = BTRFS_CSUM_SIZE;
265 char *kaddr;
266 unsigned long map_start;
267 unsigned long map_len;
268 int err;
269 u32 crc = ~(u32)0;
270 unsigned long inline_result;
271
272 len = buf->len - offset;
273 while (len > 0) {
274 err = map_private_extent_buffer(buf, offset, 32,
275 &kaddr, &map_start, &map_len);
276 if (err)
277 return 1;
278 cur_len = min(len, map_len - (offset - map_start));
279 crc = btrfs_csum_data(root, kaddr + offset - map_start,
280 crc, cur_len);
281 len -= cur_len;
282 offset += cur_len;
283 }
284 if (csum_size > sizeof(inline_result)) {
285 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
286 if (!result)
287 return 1;
288 } else {
289 result = (char *)&inline_result;
290 }
291
292 btrfs_csum_final(crc, result);
293
294 if (verify) {
295 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
296 u32 val;
297 u32 found = 0;
298 memcpy(&found, result, csum_size);
299
300 read_extent_buffer(buf, &val, 0, csum_size);
301 printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
302 "failed on %llu wanted %X found %X "
303 "level %d\n",
304 root->fs_info->sb->s_id,
305 (unsigned long long)buf->start, val, found,
306 btrfs_header_level(buf));
307 if (result != (char *)&inline_result)
308 kfree(result);
309 return 1;
310 }
311 } else {
312 write_extent_buffer(buf, result, 0, csum_size);
313 }
314 if (result != (char *)&inline_result)
315 kfree(result);
316 return 0;
317}
318
319/*
320 * we can't consider a given block up to date unless the transid of the
321 * block matches the transid in the parent node's pointer. This is how we
322 * detect blocks that either didn't get written at all or got written
323 * in the wrong place.
324 */
325static int verify_parent_transid(struct extent_io_tree *io_tree,
326 struct extent_buffer *eb, u64 parent_transid)
327{
328 struct extent_state *cached_state = NULL;
329 int ret;
330
331 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
332 return 0;
333
334 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
335 0, &cached_state, GFP_NOFS);
336 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
337 btrfs_header_generation(eb) == parent_transid) {
338 ret = 0;
339 goto out;
340 }
341 printk_ratelimited("parent transid verify failed on %llu wanted %llu "
342 "found %llu\n",
343 (unsigned long long)eb->start,
344 (unsigned long long)parent_transid,
345 (unsigned long long)btrfs_header_generation(eb));
346 ret = 1;
347 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
348out:
349 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
350 &cached_state, GFP_NOFS);
351 return ret;
352}
353
354/*
355 * helper to read a given tree block, doing retries as required when
356 * the checksums don't match and we have alternate mirrors to try.
357 */
358static int btree_read_extent_buffer_pages(struct btrfs_root *root,
359 struct extent_buffer *eb,
360 u64 start, u64 parent_transid)
361{
362 struct extent_io_tree *io_tree;
363 int ret;
364 int num_copies = 0;
365 int mirror_num = 0;
366
367 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
368 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
369 while (1) {
370 ret = read_extent_buffer_pages(io_tree, eb, start,
371 WAIT_COMPLETE,
372 btree_get_extent, mirror_num);
373 if (!ret &&
374 !verify_parent_transid(io_tree, eb, parent_transid))
375 return ret;
376
377 /*
378 * This buffer's crc is fine, but its contents are corrupted, so
379 * there is no reason to read the other copies, they won't be
380 * any less wrong.
381 */
382 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
383 return ret;
384
385 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
386 eb->start, eb->len);
387 if (num_copies == 1)
388 return ret;
389
390 mirror_num++;
391 if (mirror_num > num_copies)
392 return ret;
393 }
394 return -EIO;
395}
396
397/*
398 * checksum a dirty tree block before IO. This has extra checks to make sure
399 * we only fill in the checksum field in the first page of a multi-page block
400 */
401
402static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
403{
404 struct extent_io_tree *tree;
405 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
406 u64 found_start;
407 unsigned long len;
408 struct extent_buffer *eb;
409 int ret;
410
411 tree = &BTRFS_I(page->mapping->host)->io_tree;
412
413 if (page->private == EXTENT_PAGE_PRIVATE) {
414 WARN_ON(1);
415 goto out;
416 }
417 if (!page->private) {
418 WARN_ON(1);
419 goto out;
420 }
421 len = page->private >> 2;
422 WARN_ON(len == 0);
423
424 eb = alloc_extent_buffer(tree, start, len, page);
425 if (eb == NULL) {
426 WARN_ON(1);
427 goto out;
428 }
429 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
430 btrfs_header_generation(eb));
431 BUG_ON(ret);
432 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
433
434 found_start = btrfs_header_bytenr(eb);
435 if (found_start != start) {
436 WARN_ON(1);
437 goto err;
438 }
439 if (eb->first_page != page) {
440 WARN_ON(1);
441 goto err;
442 }
443 if (!PageUptodate(page)) {
444 WARN_ON(1);
445 goto err;
446 }
447 csum_tree_block(root, eb, 0);
448err:
449 free_extent_buffer(eb);
450out:
451 return 0;
452}
453
454static int check_tree_block_fsid(struct btrfs_root *root,
455 struct extent_buffer *eb)
456{
457 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
458 u8 fsid[BTRFS_UUID_SIZE];
459 int ret = 1;
460
461 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
462 BTRFS_FSID_SIZE);
463 while (fs_devices) {
464 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
465 ret = 0;
466 break;
467 }
468 fs_devices = fs_devices->seed;
469 }
470 return ret;
471}
472
473#define CORRUPT(reason, eb, root, slot) \
474 printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
475 "root=%llu, slot=%d\n", reason, \
476 (unsigned long long)btrfs_header_bytenr(eb), \
477 (unsigned long long)root->objectid, slot)
478
479static noinline int check_leaf(struct btrfs_root *root,
480 struct extent_buffer *leaf)
481{
482 struct btrfs_key key;
483 struct btrfs_key leaf_key;
484 u32 nritems = btrfs_header_nritems(leaf);
485 int slot;
486
487 if (nritems == 0)
488 return 0;
489
490 /* Check the 0 item */
491 if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
492 BTRFS_LEAF_DATA_SIZE(root)) {
493 CORRUPT("invalid item offset size pair", leaf, root, 0);
494 return -EIO;
495 }
496
497 /*
498 * Check to make sure each items keys are in the correct order and their
499 * offsets make sense. We only have to loop through nritems-1 because
500 * we check the current slot against the next slot, which verifies the
501 * next slot's offset+size makes sense and that the current's slot
502 * offset is correct.
503 */
504 for (slot = 0; slot < nritems - 1; slot++) {
505 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
506 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
507
508 /* Make sure the keys are in the right order */
509 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
510 CORRUPT("bad key order", leaf, root, slot);
511 return -EIO;
512 }
513
514 /*
515 * Make sure the offset and ends are right, remember that the
516 * item data starts at the end of the leaf and grows towards the
517 * front.
518 */
519 if (btrfs_item_offset_nr(leaf, slot) !=
520 btrfs_item_end_nr(leaf, slot + 1)) {
521 CORRUPT("slot offset bad", leaf, root, slot);
522 return -EIO;
523 }
524
525 /*
526 * Check to make sure that we don't point outside of the leaf,
527 * just incase all the items are consistent to eachother, but
528 * all point outside of the leaf.
529 */
530 if (btrfs_item_end_nr(leaf, slot) >
531 BTRFS_LEAF_DATA_SIZE(root)) {
532 CORRUPT("slot end outside of leaf", leaf, root, slot);
533 return -EIO;
534 }
535 }
536
537 return 0;
538}
539
540static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
541 struct extent_state *state)
542{
543 struct extent_io_tree *tree;
544 u64 found_start;
545 int found_level;
546 unsigned long len;
547 struct extent_buffer *eb;
548 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
549 int ret = 0;
550
551 tree = &BTRFS_I(page->mapping->host)->io_tree;
552 if (page->private == EXTENT_PAGE_PRIVATE)
553 goto out;
554 if (!page->private)
555 goto out;
556
557 len = page->private >> 2;
558 WARN_ON(len == 0);
559
560 eb = alloc_extent_buffer(tree, start, len, page);
561 if (eb == NULL) {
562 ret = -EIO;
563 goto out;
564 }
565
566 found_start = btrfs_header_bytenr(eb);
567 if (found_start != start) {
568 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
569 "%llu %llu\n",
570 (unsigned long long)found_start,
571 (unsigned long long)eb->start);
572 ret = -EIO;
573 goto err;
574 }
575 if (eb->first_page != page) {
576 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
577 eb->first_page->index, page->index);
578 WARN_ON(1);
579 ret = -EIO;
580 goto err;
581 }
582 if (check_tree_block_fsid(root, eb)) {
583 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
584 (unsigned long long)eb->start);
585 ret = -EIO;
586 goto err;
587 }
588 found_level = btrfs_header_level(eb);
589
590 btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
591 eb, found_level);
592
593 ret = csum_tree_block(root, eb, 1);
594 if (ret) {
595 ret = -EIO;
596 goto err;
597 }
598
599 /*
600 * If this is a leaf block and it is corrupt, set the corrupt bit so
601 * that we don't try and read the other copies of this block, just
602 * return -EIO.
603 */
604 if (found_level == 0 && check_leaf(root, eb)) {
605 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
606 ret = -EIO;
607 }
608
609 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
610 end = eb->start + end - 1;
611err:
612 free_extent_buffer(eb);
613out:
614 return ret;
615}
616
617static void end_workqueue_bio(struct bio *bio, int err)
618{
619 struct end_io_wq *end_io_wq = bio->bi_private;
620 struct btrfs_fs_info *fs_info;
621
622 fs_info = end_io_wq->info;
623 end_io_wq->error = err;
624 end_io_wq->work.func = end_workqueue_fn;
625 end_io_wq->work.flags = 0;
626
627 if (bio->bi_rw & REQ_WRITE) {
628 if (end_io_wq->metadata == 1)
629 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
630 &end_io_wq->work);
631 else if (end_io_wq->metadata == 2)
632 btrfs_queue_worker(&fs_info->endio_freespace_worker,
633 &end_io_wq->work);
634 else
635 btrfs_queue_worker(&fs_info->endio_write_workers,
636 &end_io_wq->work);
637 } else {
638 if (end_io_wq->metadata)
639 btrfs_queue_worker(&fs_info->endio_meta_workers,
640 &end_io_wq->work);
641 else
642 btrfs_queue_worker(&fs_info->endio_workers,
643 &end_io_wq->work);
644 }
645}
646
647/*
648 * For the metadata arg you want
649 *
650 * 0 - if data
651 * 1 - if normal metadta
652 * 2 - if writing to the free space cache area
653 */
654int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
655 int metadata)
656{
657 struct end_io_wq *end_io_wq;
658 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
659 if (!end_io_wq)
660 return -ENOMEM;
661
662 end_io_wq->private = bio->bi_private;
663 end_io_wq->end_io = bio->bi_end_io;
664 end_io_wq->info = info;
665 end_io_wq->error = 0;
666 end_io_wq->bio = bio;
667 end_io_wq->metadata = metadata;
668
669 bio->bi_private = end_io_wq;
670 bio->bi_end_io = end_workqueue_bio;
671 return 0;
672}
673
674unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
675{
676 unsigned long limit = min_t(unsigned long,
677 info->workers.max_workers,
678 info->fs_devices->open_devices);
679 return 256 * limit;
680}
681
682static void run_one_async_start(struct btrfs_work *work)
683{
684 struct async_submit_bio *async;
685
686 async = container_of(work, struct async_submit_bio, work);
687 async->submit_bio_start(async->inode, async->rw, async->bio,
688 async->mirror_num, async->bio_flags,
689 async->bio_offset);
690}
691
692static void run_one_async_done(struct btrfs_work *work)
693{
694 struct btrfs_fs_info *fs_info;
695 struct async_submit_bio *async;
696 int limit;
697
698 async = container_of(work, struct async_submit_bio, work);
699 fs_info = BTRFS_I(async->inode)->root->fs_info;
700
701 limit = btrfs_async_submit_limit(fs_info);
702 limit = limit * 2 / 3;
703
704 atomic_dec(&fs_info->nr_async_submits);
705
706 if (atomic_read(&fs_info->nr_async_submits) < limit &&
707 waitqueue_active(&fs_info->async_submit_wait))
708 wake_up(&fs_info->async_submit_wait);
709
710 async->submit_bio_done(async->inode, async->rw, async->bio,
711 async->mirror_num, async->bio_flags,
712 async->bio_offset);
713}
714
715static void run_one_async_free(struct btrfs_work *work)
716{
717 struct async_submit_bio *async;
718
719 async = container_of(work, struct async_submit_bio, work);
720 kfree(async);
721}
722
723int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
724 int rw, struct bio *bio, int mirror_num,
725 unsigned long bio_flags,
726 u64 bio_offset,
727 extent_submit_bio_hook_t *submit_bio_start,
728 extent_submit_bio_hook_t *submit_bio_done)
729{
730 struct async_submit_bio *async;
731
732 async = kmalloc(sizeof(*async), GFP_NOFS);
733 if (!async)
734 return -ENOMEM;
735
736 async->inode = inode;
737 async->rw = rw;
738 async->bio = bio;
739 async->mirror_num = mirror_num;
740 async->submit_bio_start = submit_bio_start;
741 async->submit_bio_done = submit_bio_done;
742
743 async->work.func = run_one_async_start;
744 async->work.ordered_func = run_one_async_done;
745 async->work.ordered_free = run_one_async_free;
746
747 async->work.flags = 0;
748 async->bio_flags = bio_flags;
749 async->bio_offset = bio_offset;
750
751 atomic_inc(&fs_info->nr_async_submits);
752
753 if (rw & REQ_SYNC)
754 btrfs_set_work_high_prio(&async->work);
755
756 btrfs_queue_worker(&fs_info->workers, &async->work);
757
758 while (atomic_read(&fs_info->async_submit_draining) &&
759 atomic_read(&fs_info->nr_async_submits)) {
760 wait_event(fs_info->async_submit_wait,
761 (atomic_read(&fs_info->nr_async_submits) == 0));
762 }
763
764 return 0;
765}
766
767static int btree_csum_one_bio(struct bio *bio)
768{
769 struct bio_vec *bvec = bio->bi_io_vec;
770 int bio_index = 0;
771 struct btrfs_root *root;
772
773 WARN_ON(bio->bi_vcnt <= 0);
774 while (bio_index < bio->bi_vcnt) {
775 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
776 csum_dirty_buffer(root, bvec->bv_page);
777 bio_index++;
778 bvec++;
779 }
780 return 0;
781}
782
783static int __btree_submit_bio_start(struct inode *inode, int rw,
784 struct bio *bio, int mirror_num,
785 unsigned long bio_flags,
786 u64 bio_offset)
787{
788 /*
789 * when we're called for a write, we're already in the async
790 * submission context. Just jump into btrfs_map_bio
791 */
792 btree_csum_one_bio(bio);
793 return 0;
794}
795
796static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
797 int mirror_num, unsigned long bio_flags,
798 u64 bio_offset)
799{
800 /*
801 * when we're called for a write, we're already in the async
802 * submission context. Just jump into btrfs_map_bio
803 */
804 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
805}
806
807static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
808 int mirror_num, unsigned long bio_flags,
809 u64 bio_offset)
810{
811 int ret;
812
813 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
814 bio, 1);
815 BUG_ON(ret);
816
817 if (!(rw & REQ_WRITE)) {
818 /*
819 * called for a read, do the setup so that checksum validation
820 * can happen in the async kernel threads
821 */
822 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
823 mirror_num, 0);
824 }
825
826 /*
827 * kthread helpers are used to submit writes so that checksumming
828 * can happen in parallel across all CPUs
829 */
830 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
831 inode, rw, bio, mirror_num, 0,
832 bio_offset,
833 __btree_submit_bio_start,
834 __btree_submit_bio_done);
835}
836
837#ifdef CONFIG_MIGRATION
838static int btree_migratepage(struct address_space *mapping,
839 struct page *newpage, struct page *page)
840{
841 /*
842 * we can't safely write a btree page from here,
843 * we haven't done the locking hook
844 */
845 if (PageDirty(page))
846 return -EAGAIN;
847 /*
848 * Buffers may be managed in a filesystem specific way.
849 * We must have no buffers or drop them.
850 */
851 if (page_has_private(page) &&
852 !try_to_release_page(page, GFP_KERNEL))
853 return -EAGAIN;
854 return migrate_page(mapping, newpage, page);
855}
856#endif
857
858static int btree_writepage(struct page *page, struct writeback_control *wbc)
859{
860 struct extent_io_tree *tree;
861 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
862 struct extent_buffer *eb;
863 int was_dirty;
864
865 tree = &BTRFS_I(page->mapping->host)->io_tree;
866 if (!(current->flags & PF_MEMALLOC)) {
867 return extent_write_full_page(tree, page,
868 btree_get_extent, wbc);
869 }
870
871 redirty_page_for_writepage(wbc, page);
872 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
873 WARN_ON(!eb);
874
875 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
876 if (!was_dirty) {
877 spin_lock(&root->fs_info->delalloc_lock);
878 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
879 spin_unlock(&root->fs_info->delalloc_lock);
880 }
881 free_extent_buffer(eb);
882
883 unlock_page(page);
884 return 0;
885}
886
887static int btree_writepages(struct address_space *mapping,
888 struct writeback_control *wbc)
889{
890 struct extent_io_tree *tree;
891 tree = &BTRFS_I(mapping->host)->io_tree;
892 if (wbc->sync_mode == WB_SYNC_NONE) {
893 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
894 u64 num_dirty;
895 unsigned long thresh = 32 * 1024 * 1024;
896
897 if (wbc->for_kupdate)
898 return 0;
899
900 /* this is a bit racy, but that's ok */
901 num_dirty = root->fs_info->dirty_metadata_bytes;
902 if (num_dirty < thresh)
903 return 0;
904 }
905 return extent_writepages(tree, mapping, btree_get_extent, wbc);
906}
907
908static int btree_readpage(struct file *file, struct page *page)
909{
910 struct extent_io_tree *tree;
911 tree = &BTRFS_I(page->mapping->host)->io_tree;
912 return extent_read_full_page(tree, page, btree_get_extent);
913}
914
915static int btree_releasepage(struct page *page, gfp_t gfp_flags)
916{
917 struct extent_io_tree *tree;
918 struct extent_map_tree *map;
919 int ret;
920
921 if (PageWriteback(page) || PageDirty(page))
922 return 0;
923
924 tree = &BTRFS_I(page->mapping->host)->io_tree;
925 map = &BTRFS_I(page->mapping->host)->extent_tree;
926
927 ret = try_release_extent_state(map, tree, page, gfp_flags);
928 if (!ret)
929 return 0;
930
931 ret = try_release_extent_buffer(tree, page);
932 if (ret == 1) {
933 ClearPagePrivate(page);
934 set_page_private(page, 0);
935 page_cache_release(page);
936 }
937
938 return ret;
939}
940
941static void btree_invalidatepage(struct page *page, unsigned long offset)
942{
943 struct extent_io_tree *tree;
944 tree = &BTRFS_I(page->mapping->host)->io_tree;
945 extent_invalidatepage(tree, page, offset);
946 btree_releasepage(page, GFP_NOFS);
947 if (PagePrivate(page)) {
948 printk(KERN_WARNING "btrfs warning page private not zero "
949 "on page %llu\n", (unsigned long long)page_offset(page));
950 ClearPagePrivate(page);
951 set_page_private(page, 0);
952 page_cache_release(page);
953 }
954}
955
956static const struct address_space_operations btree_aops = {
957 .readpage = btree_readpage,
958 .writepage = btree_writepage,
959 .writepages = btree_writepages,
960 .releasepage = btree_releasepage,
961 .invalidatepage = btree_invalidatepage,
962#ifdef CONFIG_MIGRATION
963 .migratepage = btree_migratepage,
964#endif
965};
966
967int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
968 u64 parent_transid)
969{
970 struct extent_buffer *buf = NULL;
971 struct inode *btree_inode = root->fs_info->btree_inode;
972 int ret = 0;
973
974 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
975 if (!buf)
976 return 0;
977 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
978 buf, 0, WAIT_NONE, btree_get_extent, 0);
979 free_extent_buffer(buf);
980 return ret;
981}
982
983int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
984 int mirror_num, struct extent_buffer **eb)
985{
986 struct extent_buffer *buf = NULL;
987 struct inode *btree_inode = root->fs_info->btree_inode;
988 struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
989 int ret;
990
991 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
992 if (!buf)
993 return 0;
994
995 set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
996
997 ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
998 btree_get_extent, mirror_num);
999 if (ret) {
1000 free_extent_buffer(buf);
1001 return ret;
1002 }
1003
1004 if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1005 free_extent_buffer(buf);
1006 return -EIO;
1007 } else if (extent_buffer_uptodate(io_tree, buf, NULL)) {
1008 *eb = buf;
1009 } else {
1010 free_extent_buffer(buf);
1011 }
1012 return 0;
1013}
1014
1015struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1016 u64 bytenr, u32 blocksize)
1017{
1018 struct inode *btree_inode = root->fs_info->btree_inode;
1019 struct extent_buffer *eb;
1020 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1021 bytenr, blocksize);
1022 return eb;
1023}
1024
1025struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1026 u64 bytenr, u32 blocksize)
1027{
1028 struct inode *btree_inode = root->fs_info->btree_inode;
1029 struct extent_buffer *eb;
1030
1031 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1032 bytenr, blocksize, NULL);
1033 return eb;
1034}
1035
1036
1037int btrfs_write_tree_block(struct extent_buffer *buf)
1038{
1039 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
1040 buf->start + buf->len - 1);
1041}
1042
1043int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1044{
1045 return filemap_fdatawait_range(buf->first_page->mapping,
1046 buf->start, buf->start + buf->len - 1);
1047}
1048
1049struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1050 u32 blocksize, u64 parent_transid)
1051{
1052 struct extent_buffer *buf = NULL;
1053 int ret;
1054
1055 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1056 if (!buf)
1057 return NULL;
1058
1059 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1060
1061 if (ret == 0)
1062 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1063 return buf;
1064
1065}
1066
1067int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1068 struct extent_buffer *buf)
1069{
1070 struct inode *btree_inode = root->fs_info->btree_inode;
1071 if (btrfs_header_generation(buf) ==
1072 root->fs_info->running_transaction->transid) {
1073 btrfs_assert_tree_locked(buf);
1074
1075 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1076 spin_lock(&root->fs_info->delalloc_lock);
1077 if (root->fs_info->dirty_metadata_bytes >= buf->len)
1078 root->fs_info->dirty_metadata_bytes -= buf->len;
1079 else
1080 WARN_ON(1);
1081 spin_unlock(&root->fs_info->delalloc_lock);
1082 }
1083
1084 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1085 btrfs_set_lock_blocking(buf);
1086 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1087 buf);
1088 }
1089 return 0;
1090}
1091
1092static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1093 u32 stripesize, struct btrfs_root *root,
1094 struct btrfs_fs_info *fs_info,
1095 u64 objectid)
1096{
1097 root->node = NULL;
1098 root->commit_root = NULL;
1099 root->sectorsize = sectorsize;
1100 root->nodesize = nodesize;
1101 root->leafsize = leafsize;
1102 root->stripesize = stripesize;
1103 root->ref_cows = 0;
1104 root->track_dirty = 0;
1105 root->in_radix = 0;
1106 root->orphan_item_inserted = 0;
1107 root->orphan_cleanup_state = 0;
1108
1109 root->fs_info = fs_info;
1110 root->objectid = objectid;
1111 root->last_trans = 0;
1112 root->highest_objectid = 0;
1113 root->name = NULL;
1114 root->inode_tree = RB_ROOT;
1115 INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1116 root->block_rsv = NULL;
1117 root->orphan_block_rsv = NULL;
1118
1119 INIT_LIST_HEAD(&root->dirty_list);
1120 INIT_LIST_HEAD(&root->orphan_list);
1121 INIT_LIST_HEAD(&root->root_list);
1122 spin_lock_init(&root->orphan_lock);
1123 spin_lock_init(&root->inode_lock);
1124 spin_lock_init(&root->accounting_lock);
1125 mutex_init(&root->objectid_mutex);
1126 mutex_init(&root->log_mutex);
1127 init_waitqueue_head(&root->log_writer_wait);
1128 init_waitqueue_head(&root->log_commit_wait[0]);
1129 init_waitqueue_head(&root->log_commit_wait[1]);
1130 atomic_set(&root->log_commit[0], 0);
1131 atomic_set(&root->log_commit[1], 0);
1132 atomic_set(&root->log_writers, 0);
1133 root->log_batch = 0;
1134 root->log_transid = 0;
1135 root->last_log_commit = 0;
1136 extent_io_tree_init(&root->dirty_log_pages,
1137 fs_info->btree_inode->i_mapping);
1138
1139 memset(&root->root_key, 0, sizeof(root->root_key));
1140 memset(&root->root_item, 0, sizeof(root->root_item));
1141 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1142 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1143 root->defrag_trans_start = fs_info->generation;
1144 init_completion(&root->kobj_unregister);
1145 root->defrag_running = 0;
1146 root->root_key.objectid = objectid;
1147 root->anon_dev = 0;
1148 return 0;
1149}
1150
1151static int find_and_setup_root(struct btrfs_root *tree_root,
1152 struct btrfs_fs_info *fs_info,
1153 u64 objectid,
1154 struct btrfs_root *root)
1155{
1156 int ret;
1157 u32 blocksize;
1158 u64 generation;
1159
1160 __setup_root(tree_root->nodesize, tree_root->leafsize,
1161 tree_root->sectorsize, tree_root->stripesize,
1162 root, fs_info, objectid);
1163 ret = btrfs_find_last_root(tree_root, objectid,
1164 &root->root_item, &root->root_key);
1165 if (ret > 0)
1166 return -ENOENT;
1167 BUG_ON(ret);
1168
1169 generation = btrfs_root_generation(&root->root_item);
1170 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1171 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1172 blocksize, generation);
1173 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1174 free_extent_buffer(root->node);
1175 return -EIO;
1176 }
1177 root->commit_root = btrfs_root_node(root);
1178 return 0;
1179}
1180
1181static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1182 struct btrfs_fs_info *fs_info)
1183{
1184 struct btrfs_root *root;
1185 struct btrfs_root *tree_root = fs_info->tree_root;
1186 struct extent_buffer *leaf;
1187
1188 root = kzalloc(sizeof(*root), GFP_NOFS);
1189 if (!root)
1190 return ERR_PTR(-ENOMEM);
1191
1192 __setup_root(tree_root->nodesize, tree_root->leafsize,
1193 tree_root->sectorsize, tree_root->stripesize,
1194 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1195
1196 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1197 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1198 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1199 /*
1200 * log trees do not get reference counted because they go away
1201 * before a real commit is actually done. They do store pointers
1202 * to file data extents, and those reference counts still get
1203 * updated (along with back refs to the log tree).
1204 */
1205 root->ref_cows = 0;
1206
1207 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1208 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1209 if (IS_ERR(leaf)) {
1210 kfree(root);
1211 return ERR_CAST(leaf);
1212 }
1213
1214 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1215 btrfs_set_header_bytenr(leaf, leaf->start);
1216 btrfs_set_header_generation(leaf, trans->transid);
1217 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1218 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1219 root->node = leaf;
1220
1221 write_extent_buffer(root->node, root->fs_info->fsid,
1222 (unsigned long)btrfs_header_fsid(root->node),
1223 BTRFS_FSID_SIZE);
1224 btrfs_mark_buffer_dirty(root->node);
1225 btrfs_tree_unlock(root->node);
1226 return root;
1227}
1228
1229int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1230 struct btrfs_fs_info *fs_info)
1231{
1232 struct btrfs_root *log_root;
1233
1234 log_root = alloc_log_tree(trans, fs_info);
1235 if (IS_ERR(log_root))
1236 return PTR_ERR(log_root);
1237 WARN_ON(fs_info->log_root_tree);
1238 fs_info->log_root_tree = log_root;
1239 return 0;
1240}
1241
1242int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1243 struct btrfs_root *root)
1244{
1245 struct btrfs_root *log_root;
1246 struct btrfs_inode_item *inode_item;
1247
1248 log_root = alloc_log_tree(trans, root->fs_info);
1249 if (IS_ERR(log_root))
1250 return PTR_ERR(log_root);
1251
1252 log_root->last_trans = trans->transid;
1253 log_root->root_key.offset = root->root_key.objectid;
1254
1255 inode_item = &log_root->root_item.inode;
1256 inode_item->generation = cpu_to_le64(1);
1257 inode_item->size = cpu_to_le64(3);
1258 inode_item->nlink = cpu_to_le32(1);
1259 inode_item->nbytes = cpu_to_le64(root->leafsize);
1260 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1261
1262 btrfs_set_root_node(&log_root->root_item, log_root->node);
1263
1264 WARN_ON(root->log_root);
1265 root->log_root = log_root;
1266 root->log_transid = 0;
1267 root->last_log_commit = 0;
1268 return 0;
1269}
1270
1271struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1272 struct btrfs_key *location)
1273{
1274 struct btrfs_root *root;
1275 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1276 struct btrfs_path *path;
1277 struct extent_buffer *l;
1278 u64 generation;
1279 u32 blocksize;
1280 int ret = 0;
1281
1282 root = kzalloc(sizeof(*root), GFP_NOFS);
1283 if (!root)
1284 return ERR_PTR(-ENOMEM);
1285 if (location->offset == (u64)-1) {
1286 ret = find_and_setup_root(tree_root, fs_info,
1287 location->objectid, root);
1288 if (ret) {
1289 kfree(root);
1290 return ERR_PTR(ret);
1291 }
1292 goto out;
1293 }
1294
1295 __setup_root(tree_root->nodesize, tree_root->leafsize,
1296 tree_root->sectorsize, tree_root->stripesize,
1297 root, fs_info, location->objectid);
1298
1299 path = btrfs_alloc_path();
1300 if (!path) {
1301 kfree(root);
1302 return ERR_PTR(-ENOMEM);
1303 }
1304 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1305 if (ret == 0) {
1306 l = path->nodes[0];
1307 read_extent_buffer(l, &root->root_item,
1308 btrfs_item_ptr_offset(l, path->slots[0]),
1309 sizeof(root->root_item));
1310 memcpy(&root->root_key, location, sizeof(*location));
1311 }
1312 btrfs_free_path(path);
1313 if (ret) {
1314 kfree(root);
1315 if (ret > 0)
1316 ret = -ENOENT;
1317 return ERR_PTR(ret);
1318 }
1319
1320 generation = btrfs_root_generation(&root->root_item);
1321 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1322 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1323 blocksize, generation);
1324 root->commit_root = btrfs_root_node(root);
1325 BUG_ON(!root->node);
1326out:
1327 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1328 root->ref_cows = 1;
1329 btrfs_check_and_init_root_item(&root->root_item);
1330 }
1331
1332 return root;
1333}
1334
1335struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1336 struct btrfs_key *location)
1337{
1338 struct btrfs_root *root;
1339 int ret;
1340
1341 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1342 return fs_info->tree_root;
1343 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1344 return fs_info->extent_root;
1345 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1346 return fs_info->chunk_root;
1347 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1348 return fs_info->dev_root;
1349 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1350 return fs_info->csum_root;
1351again:
1352 spin_lock(&fs_info->fs_roots_radix_lock);
1353 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1354 (unsigned long)location->objectid);
1355 spin_unlock(&fs_info->fs_roots_radix_lock);
1356 if (root)
1357 return root;
1358
1359 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1360 if (IS_ERR(root))
1361 return root;
1362
1363 root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1364 root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1365 GFP_NOFS);
1366 if (!root->free_ino_pinned || !root->free_ino_ctl) {
1367 ret = -ENOMEM;
1368 goto fail;
1369 }
1370
1371 btrfs_init_free_ino_ctl(root);
1372 mutex_init(&root->fs_commit_mutex);
1373 spin_lock_init(&root->cache_lock);
1374 init_waitqueue_head(&root->cache_wait);
1375
1376 ret = get_anon_bdev(&root->anon_dev);
1377 if (ret)
1378 goto fail;
1379
1380 if (btrfs_root_refs(&root->root_item) == 0) {
1381 ret = -ENOENT;
1382 goto fail;
1383 }
1384
1385 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1386 if (ret < 0)
1387 goto fail;
1388 if (ret == 0)
1389 root->orphan_item_inserted = 1;
1390
1391 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1392 if (ret)
1393 goto fail;
1394
1395 spin_lock(&fs_info->fs_roots_radix_lock);
1396 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1397 (unsigned long)root->root_key.objectid,
1398 root);
1399 if (ret == 0)
1400 root->in_radix = 1;
1401
1402 spin_unlock(&fs_info->fs_roots_radix_lock);
1403 radix_tree_preload_end();
1404 if (ret) {
1405 if (ret == -EEXIST) {
1406 free_fs_root(root);
1407 goto again;
1408 }
1409 goto fail;
1410 }
1411
1412 ret = btrfs_find_dead_roots(fs_info->tree_root,
1413 root->root_key.objectid);
1414 WARN_ON(ret);
1415 return root;
1416fail:
1417 free_fs_root(root);
1418 return ERR_PTR(ret);
1419}
1420
1421static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1422{
1423 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1424 int ret = 0;
1425 struct btrfs_device *device;
1426 struct backing_dev_info *bdi;
1427
1428 rcu_read_lock();
1429 list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1430 if (!device->bdev)
1431 continue;
1432 bdi = blk_get_backing_dev_info(device->bdev);
1433 if (bdi && bdi_congested(bdi, bdi_bits)) {
1434 ret = 1;
1435 break;
1436 }
1437 }
1438 rcu_read_unlock();
1439 return ret;
1440}
1441
1442/*
1443 * If this fails, caller must call bdi_destroy() to get rid of the
1444 * bdi again.
1445 */
1446static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1447{
1448 int err;
1449
1450 bdi->capabilities = BDI_CAP_MAP_COPY;
1451 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1452 if (err)
1453 return err;
1454
1455 bdi->ra_pages = default_backing_dev_info.ra_pages;
1456 bdi->congested_fn = btrfs_congested_fn;
1457 bdi->congested_data = info;
1458 return 0;
1459}
1460
1461static int bio_ready_for_csum(struct bio *bio)
1462{
1463 u64 length = 0;
1464 u64 buf_len = 0;
1465 u64 start = 0;
1466 struct page *page;
1467 struct extent_io_tree *io_tree = NULL;
1468 struct bio_vec *bvec;
1469 int i;
1470 int ret;
1471
1472 bio_for_each_segment(bvec, bio, i) {
1473 page = bvec->bv_page;
1474 if (page->private == EXTENT_PAGE_PRIVATE) {
1475 length += bvec->bv_len;
1476 continue;
1477 }
1478 if (!page->private) {
1479 length += bvec->bv_len;
1480 continue;
1481 }
1482 length = bvec->bv_len;
1483 buf_len = page->private >> 2;
1484 start = page_offset(page) + bvec->bv_offset;
1485 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1486 }
1487 /* are we fully contained in this bio? */
1488 if (buf_len <= length)
1489 return 1;
1490
1491 ret = extent_range_uptodate(io_tree, start + length,
1492 start + buf_len - 1);
1493 return ret;
1494}
1495
1496/*
1497 * called by the kthread helper functions to finally call the bio end_io
1498 * functions. This is where read checksum verification actually happens
1499 */
1500static void end_workqueue_fn(struct btrfs_work *work)
1501{
1502 struct bio *bio;
1503 struct end_io_wq *end_io_wq;
1504 struct btrfs_fs_info *fs_info;
1505 int error;
1506
1507 end_io_wq = container_of(work, struct end_io_wq, work);
1508 bio = end_io_wq->bio;
1509 fs_info = end_io_wq->info;
1510
1511 /* metadata bio reads are special because the whole tree block must
1512 * be checksummed at once. This makes sure the entire block is in
1513 * ram and up to date before trying to verify things. For
1514 * blocksize <= pagesize, it is basically a noop
1515 */
1516 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1517 !bio_ready_for_csum(bio)) {
1518 btrfs_queue_worker(&fs_info->endio_meta_workers,
1519 &end_io_wq->work);
1520 return;
1521 }
1522 error = end_io_wq->error;
1523 bio->bi_private = end_io_wq->private;
1524 bio->bi_end_io = end_io_wq->end_io;
1525 kfree(end_io_wq);
1526 bio_endio(bio, error);
1527}
1528
1529static int cleaner_kthread(void *arg)
1530{
1531 struct btrfs_root *root = arg;
1532
1533 do {
1534 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1535
1536 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1537 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1538 btrfs_run_delayed_iputs(root);
1539 btrfs_clean_old_snapshots(root);
1540 mutex_unlock(&root->fs_info->cleaner_mutex);
1541 btrfs_run_defrag_inodes(root->fs_info);
1542 }
1543
1544 if (freezing(current)) {
1545 refrigerator();
1546 } else {
1547 set_current_state(TASK_INTERRUPTIBLE);
1548 if (!kthread_should_stop())
1549 schedule();
1550 __set_current_state(TASK_RUNNING);
1551 }
1552 } while (!kthread_should_stop());
1553 return 0;
1554}
1555
1556static int transaction_kthread(void *arg)
1557{
1558 struct btrfs_root *root = arg;
1559 struct btrfs_trans_handle *trans;
1560 struct btrfs_transaction *cur;
1561 u64 transid;
1562 unsigned long now;
1563 unsigned long delay;
1564 int ret;
1565
1566 do {
1567 delay = HZ * 30;
1568 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1569 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1570
1571 spin_lock(&root->fs_info->trans_lock);
1572 cur = root->fs_info->running_transaction;
1573 if (!cur) {
1574 spin_unlock(&root->fs_info->trans_lock);
1575 goto sleep;
1576 }
1577
1578 now = get_seconds();
1579 if (!cur->blocked &&
1580 (now < cur->start_time || now - cur->start_time < 30)) {
1581 spin_unlock(&root->fs_info->trans_lock);
1582 delay = HZ * 5;
1583 goto sleep;
1584 }
1585 transid = cur->transid;
1586 spin_unlock(&root->fs_info->trans_lock);
1587
1588 trans = btrfs_join_transaction(root);
1589 BUG_ON(IS_ERR(trans));
1590 if (transid == trans->transid) {
1591 ret = btrfs_commit_transaction(trans, root);
1592 BUG_ON(ret);
1593 } else {
1594 btrfs_end_transaction(trans, root);
1595 }
1596sleep:
1597 wake_up_process(root->fs_info->cleaner_kthread);
1598 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1599
1600 if (freezing(current)) {
1601 refrigerator();
1602 } else {
1603 set_current_state(TASK_INTERRUPTIBLE);
1604 if (!kthread_should_stop() &&
1605 !btrfs_transaction_blocked(root->fs_info))
1606 schedule_timeout(delay);
1607 __set_current_state(TASK_RUNNING);
1608 }
1609 } while (!kthread_should_stop());
1610 return 0;
1611}
1612
1613struct btrfs_root *open_ctree(struct super_block *sb,
1614 struct btrfs_fs_devices *fs_devices,
1615 char *options)
1616{
1617 u32 sectorsize;
1618 u32 nodesize;
1619 u32 leafsize;
1620 u32 blocksize;
1621 u32 stripesize;
1622 u64 generation;
1623 u64 features;
1624 struct btrfs_key location;
1625 struct buffer_head *bh;
1626 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1627 GFP_NOFS);
1628 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1629 GFP_NOFS);
1630 struct btrfs_root *tree_root = btrfs_sb(sb);
1631 struct btrfs_fs_info *fs_info = NULL;
1632 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1633 GFP_NOFS);
1634 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1635 GFP_NOFS);
1636 struct btrfs_root *log_tree_root;
1637
1638 int ret;
1639 int err = -EINVAL;
1640
1641 struct btrfs_super_block *disk_super;
1642
1643 if (!extent_root || !tree_root || !tree_root->fs_info ||
1644 !chunk_root || !dev_root || !csum_root) {
1645 err = -ENOMEM;
1646 goto fail;
1647 }
1648 fs_info = tree_root->fs_info;
1649
1650 ret = init_srcu_struct(&fs_info->subvol_srcu);
1651 if (ret) {
1652 err = ret;
1653 goto fail;
1654 }
1655
1656 ret = setup_bdi(fs_info, &fs_info->bdi);
1657 if (ret) {
1658 err = ret;
1659 goto fail_srcu;
1660 }
1661
1662 fs_info->btree_inode = new_inode(sb);
1663 if (!fs_info->btree_inode) {
1664 err = -ENOMEM;
1665 goto fail_bdi;
1666 }
1667
1668 mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1669
1670 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1671 INIT_LIST_HEAD(&fs_info->trans_list);
1672 INIT_LIST_HEAD(&fs_info->dead_roots);
1673 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1674 INIT_LIST_HEAD(&fs_info->hashers);
1675 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1676 INIT_LIST_HEAD(&fs_info->ordered_operations);
1677 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1678 spin_lock_init(&fs_info->delalloc_lock);
1679 spin_lock_init(&fs_info->trans_lock);
1680 spin_lock_init(&fs_info->ref_cache_lock);
1681 spin_lock_init(&fs_info->fs_roots_radix_lock);
1682 spin_lock_init(&fs_info->delayed_iput_lock);
1683 spin_lock_init(&fs_info->defrag_inodes_lock);
1684 mutex_init(&fs_info->reloc_mutex);
1685
1686 init_completion(&fs_info->kobj_unregister);
1687 fs_info->tree_root = tree_root;
1688 fs_info->extent_root = extent_root;
1689 fs_info->csum_root = csum_root;
1690 fs_info->chunk_root = chunk_root;
1691 fs_info->dev_root = dev_root;
1692 fs_info->fs_devices = fs_devices;
1693 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1694 INIT_LIST_HEAD(&fs_info->space_info);
1695 btrfs_mapping_init(&fs_info->mapping_tree);
1696 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1697 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1698 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1699 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1700 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1701 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1702 mutex_init(&fs_info->durable_block_rsv_mutex);
1703 atomic_set(&fs_info->nr_async_submits, 0);
1704 atomic_set(&fs_info->async_delalloc_pages, 0);
1705 atomic_set(&fs_info->async_submit_draining, 0);
1706 atomic_set(&fs_info->nr_async_bios, 0);
1707 atomic_set(&fs_info->defrag_running, 0);
1708 fs_info->sb = sb;
1709 fs_info->max_inline = 8192 * 1024;
1710 fs_info->metadata_ratio = 0;
1711 fs_info->defrag_inodes = RB_ROOT;
1712 fs_info->trans_no_join = 0;
1713
1714 /* readahead state */
1715 INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
1716 spin_lock_init(&fs_info->reada_lock);
1717
1718 fs_info->thread_pool_size = min_t(unsigned long,
1719 num_online_cpus() + 2, 8);
1720
1721 INIT_LIST_HEAD(&fs_info->ordered_extents);
1722 spin_lock_init(&fs_info->ordered_extent_lock);
1723 fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1724 GFP_NOFS);
1725 if (!fs_info->delayed_root) {
1726 err = -ENOMEM;
1727 goto fail_iput;
1728 }
1729 btrfs_init_delayed_root(fs_info->delayed_root);
1730
1731 mutex_init(&fs_info->scrub_lock);
1732 atomic_set(&fs_info->scrubs_running, 0);
1733 atomic_set(&fs_info->scrub_pause_req, 0);
1734 atomic_set(&fs_info->scrubs_paused, 0);
1735 atomic_set(&fs_info->scrub_cancel_req, 0);
1736 init_waitqueue_head(&fs_info->scrub_pause_wait);
1737 init_rwsem(&fs_info->scrub_super_lock);
1738 fs_info->scrub_workers_refcnt = 0;
1739
1740 sb->s_blocksize = 4096;
1741 sb->s_blocksize_bits = blksize_bits(4096);
1742 sb->s_bdi = &fs_info->bdi;
1743
1744 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1745 fs_info->btree_inode->i_nlink = 1;
1746 /*
1747 * we set the i_size on the btree inode to the max possible int.
1748 * the real end of the address space is determined by all of
1749 * the devices in the system
1750 */
1751 fs_info->btree_inode->i_size = OFFSET_MAX;
1752 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1753 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1754
1755 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1756 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1757 fs_info->btree_inode->i_mapping);
1758 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
1759
1760 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1761
1762 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1763 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1764 sizeof(struct btrfs_key));
1765 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1766 insert_inode_hash(fs_info->btree_inode);
1767
1768 spin_lock_init(&fs_info->block_group_cache_lock);
1769 fs_info->block_group_cache_tree = RB_ROOT;
1770
1771 extent_io_tree_init(&fs_info->freed_extents[0],
1772 fs_info->btree_inode->i_mapping);
1773 extent_io_tree_init(&fs_info->freed_extents[1],
1774 fs_info->btree_inode->i_mapping);
1775 fs_info->pinned_extents = &fs_info->freed_extents[0];
1776 fs_info->do_barriers = 1;
1777
1778
1779 mutex_init(&fs_info->ordered_operations_mutex);
1780 mutex_init(&fs_info->tree_log_mutex);
1781 mutex_init(&fs_info->chunk_mutex);
1782 mutex_init(&fs_info->transaction_kthread_mutex);
1783 mutex_init(&fs_info->cleaner_mutex);
1784 mutex_init(&fs_info->volume_mutex);
1785 init_rwsem(&fs_info->extent_commit_sem);
1786 init_rwsem(&fs_info->cleanup_work_sem);
1787 init_rwsem(&fs_info->subvol_sem);
1788
1789 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1790 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1791
1792 init_waitqueue_head(&fs_info->transaction_throttle);
1793 init_waitqueue_head(&fs_info->transaction_wait);
1794 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1795 init_waitqueue_head(&fs_info->async_submit_wait);
1796
1797 __setup_root(4096, 4096, 4096, 4096, tree_root,
1798 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1799
1800 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1801 if (!bh) {
1802 err = -EINVAL;
1803 goto fail_alloc;
1804 }
1805
1806 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1807 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1808 sizeof(fs_info->super_for_commit));
1809 brelse(bh);
1810
1811 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1812
1813 disk_super = &fs_info->super_copy;
1814 if (!btrfs_super_root(disk_super))
1815 goto fail_alloc;
1816
1817 /* check FS state, whether FS is broken. */
1818 fs_info->fs_state |= btrfs_super_flags(disk_super);
1819
1820 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1821
1822 /*
1823 * In the long term, we'll store the compression type in the super
1824 * block, and it'll be used for per file compression control.
1825 */
1826 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
1827
1828 ret = btrfs_parse_options(tree_root, options);
1829 if (ret) {
1830 err = ret;
1831 goto fail_alloc;
1832 }
1833
1834 features = btrfs_super_incompat_flags(disk_super) &
1835 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1836 if (features) {
1837 printk(KERN_ERR "BTRFS: couldn't mount because of "
1838 "unsupported optional features (%Lx).\n",
1839 (unsigned long long)features);
1840 err = -EINVAL;
1841 goto fail_alloc;
1842 }
1843
1844 features = btrfs_super_incompat_flags(disk_super);
1845 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1846 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1847 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1848 btrfs_set_super_incompat_flags(disk_super, features);
1849
1850 features = btrfs_super_compat_ro_flags(disk_super) &
1851 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1852 if (!(sb->s_flags & MS_RDONLY) && features) {
1853 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1854 "unsupported option features (%Lx).\n",
1855 (unsigned long long)features);
1856 err = -EINVAL;
1857 goto fail_alloc;
1858 }
1859
1860 btrfs_init_workers(&fs_info->generic_worker,
1861 "genwork", 1, NULL);
1862
1863 btrfs_init_workers(&fs_info->workers, "worker",
1864 fs_info->thread_pool_size,
1865 &fs_info->generic_worker);
1866
1867 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1868 fs_info->thread_pool_size,
1869 &fs_info->generic_worker);
1870
1871 btrfs_init_workers(&fs_info->submit_workers, "submit",
1872 min_t(u64, fs_devices->num_devices,
1873 fs_info->thread_pool_size),
1874 &fs_info->generic_worker);
1875
1876 btrfs_init_workers(&fs_info->caching_workers, "cache",
1877 2, &fs_info->generic_worker);
1878
1879 /* a higher idle thresh on the submit workers makes it much more
1880 * likely that bios will be send down in a sane order to the
1881 * devices
1882 */
1883 fs_info->submit_workers.idle_thresh = 64;
1884
1885 fs_info->workers.idle_thresh = 16;
1886 fs_info->workers.ordered = 1;
1887
1888 fs_info->delalloc_workers.idle_thresh = 2;
1889 fs_info->delalloc_workers.ordered = 1;
1890
1891 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1892 &fs_info->generic_worker);
1893 btrfs_init_workers(&fs_info->endio_workers, "endio",
1894 fs_info->thread_pool_size,
1895 &fs_info->generic_worker);
1896 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1897 fs_info->thread_pool_size,
1898 &fs_info->generic_worker);
1899 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1900 "endio-meta-write", fs_info->thread_pool_size,
1901 &fs_info->generic_worker);
1902 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1903 fs_info->thread_pool_size,
1904 &fs_info->generic_worker);
1905 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1906 1, &fs_info->generic_worker);
1907 btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
1908 fs_info->thread_pool_size,
1909 &fs_info->generic_worker);
1910 btrfs_init_workers(&fs_info->readahead_workers, "readahead",
1911 fs_info->thread_pool_size,
1912 &fs_info->generic_worker);
1913
1914 /*
1915 * endios are largely parallel and should have a very
1916 * low idle thresh
1917 */
1918 fs_info->endio_workers.idle_thresh = 4;
1919 fs_info->endio_meta_workers.idle_thresh = 4;
1920
1921 fs_info->endio_write_workers.idle_thresh = 2;
1922 fs_info->endio_meta_write_workers.idle_thresh = 2;
1923 fs_info->readahead_workers.idle_thresh = 2;
1924
1925 btrfs_start_workers(&fs_info->workers, 1);
1926 btrfs_start_workers(&fs_info->generic_worker, 1);
1927 btrfs_start_workers(&fs_info->submit_workers, 1);
1928 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1929 btrfs_start_workers(&fs_info->fixup_workers, 1);
1930 btrfs_start_workers(&fs_info->endio_workers, 1);
1931 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1932 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1933 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1934 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1935 btrfs_start_workers(&fs_info->delayed_workers, 1);
1936 btrfs_start_workers(&fs_info->caching_workers, 1);
1937 btrfs_start_workers(&fs_info->readahead_workers, 1);
1938
1939 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1940 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1941 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1942
1943 nodesize = btrfs_super_nodesize(disk_super);
1944 leafsize = btrfs_super_leafsize(disk_super);
1945 sectorsize = btrfs_super_sectorsize(disk_super);
1946 stripesize = btrfs_super_stripesize(disk_super);
1947 tree_root->nodesize = nodesize;
1948 tree_root->leafsize = leafsize;
1949 tree_root->sectorsize = sectorsize;
1950 tree_root->stripesize = stripesize;
1951
1952 sb->s_blocksize = sectorsize;
1953 sb->s_blocksize_bits = blksize_bits(sectorsize);
1954
1955 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1956 sizeof(disk_super->magic))) {
1957 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1958 goto fail_sb_buffer;
1959 }
1960
1961 mutex_lock(&fs_info->chunk_mutex);
1962 ret = btrfs_read_sys_array(tree_root);
1963 mutex_unlock(&fs_info->chunk_mutex);
1964 if (ret) {
1965 printk(KERN_WARNING "btrfs: failed to read the system "
1966 "array on %s\n", sb->s_id);
1967 goto fail_sb_buffer;
1968 }
1969
1970 blocksize = btrfs_level_size(tree_root,
1971 btrfs_super_chunk_root_level(disk_super));
1972 generation = btrfs_super_chunk_root_generation(disk_super);
1973
1974 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1975 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1976
1977 chunk_root->node = read_tree_block(chunk_root,
1978 btrfs_super_chunk_root(disk_super),
1979 blocksize, generation);
1980 BUG_ON(!chunk_root->node);
1981 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1982 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1983 sb->s_id);
1984 goto fail_chunk_root;
1985 }
1986 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1987 chunk_root->commit_root = btrfs_root_node(chunk_root);
1988
1989 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1990 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1991 BTRFS_UUID_SIZE);
1992
1993 mutex_lock(&fs_info->chunk_mutex);
1994 ret = btrfs_read_chunk_tree(chunk_root);
1995 mutex_unlock(&fs_info->chunk_mutex);
1996 if (ret) {
1997 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1998 sb->s_id);
1999 goto fail_chunk_root;
2000 }
2001
2002 btrfs_close_extra_devices(fs_devices);
2003
2004 blocksize = btrfs_level_size(tree_root,
2005 btrfs_super_root_level(disk_super));
2006 generation = btrfs_super_generation(disk_super);
2007
2008 tree_root->node = read_tree_block(tree_root,
2009 btrfs_super_root(disk_super),
2010 blocksize, generation);
2011 if (!tree_root->node)
2012 goto fail_chunk_root;
2013 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2014 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2015 sb->s_id);
2016 goto fail_tree_root;
2017 }
2018 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2019 tree_root->commit_root = btrfs_root_node(tree_root);
2020
2021 ret = find_and_setup_root(tree_root, fs_info,
2022 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2023 if (ret)
2024 goto fail_tree_root;
2025 extent_root->track_dirty = 1;
2026
2027 ret = find_and_setup_root(tree_root, fs_info,
2028 BTRFS_DEV_TREE_OBJECTID, dev_root);
2029 if (ret)
2030 goto fail_extent_root;
2031 dev_root->track_dirty = 1;
2032
2033 ret = find_and_setup_root(tree_root, fs_info,
2034 BTRFS_CSUM_TREE_OBJECTID, csum_root);
2035 if (ret)
2036 goto fail_dev_root;
2037
2038 csum_root->track_dirty = 1;
2039
2040 fs_info->generation = generation;
2041 fs_info->last_trans_committed = generation;
2042 fs_info->data_alloc_profile = (u64)-1;
2043 fs_info->metadata_alloc_profile = (u64)-1;
2044 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
2045
2046 ret = btrfs_init_space_info(fs_info);
2047 if (ret) {
2048 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2049 goto fail_block_groups;
2050 }
2051
2052 ret = btrfs_read_block_groups(extent_root);
2053 if (ret) {
2054 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2055 goto fail_block_groups;
2056 }
2057
2058 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2059 "btrfs-cleaner");
2060 if (IS_ERR(fs_info->cleaner_kthread))
2061 goto fail_block_groups;
2062
2063 fs_info->transaction_kthread = kthread_run(transaction_kthread,
2064 tree_root,
2065 "btrfs-transaction");
2066 if (IS_ERR(fs_info->transaction_kthread))
2067 goto fail_cleaner;
2068
2069 if (!btrfs_test_opt(tree_root, SSD) &&
2070 !btrfs_test_opt(tree_root, NOSSD) &&
2071 !fs_info->fs_devices->rotating) {
2072 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2073 "mode\n");
2074 btrfs_set_opt(fs_info->mount_opt, SSD);
2075 }
2076
2077 /* do not make disk changes in broken FS */
2078 if (btrfs_super_log_root(disk_super) != 0 &&
2079 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2080 u64 bytenr = btrfs_super_log_root(disk_super);
2081
2082 if (fs_devices->rw_devices == 0) {
2083 printk(KERN_WARNING "Btrfs log replay required "
2084 "on RO media\n");
2085 err = -EIO;
2086 goto fail_trans_kthread;
2087 }
2088 blocksize =
2089 btrfs_level_size(tree_root,
2090 btrfs_super_log_root_level(disk_super));
2091
2092 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2093 if (!log_tree_root) {
2094 err = -ENOMEM;
2095 goto fail_trans_kthread;
2096 }
2097
2098 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2099 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2100
2101 log_tree_root->node = read_tree_block(tree_root, bytenr,
2102 blocksize,
2103 generation + 1);
2104 ret = btrfs_recover_log_trees(log_tree_root);
2105 BUG_ON(ret);
2106
2107 if (sb->s_flags & MS_RDONLY) {
2108 ret = btrfs_commit_super(tree_root);
2109 BUG_ON(ret);
2110 }
2111 }
2112
2113 ret = btrfs_find_orphan_roots(tree_root);
2114 BUG_ON(ret);
2115
2116 if (!(sb->s_flags & MS_RDONLY)) {
2117 ret = btrfs_cleanup_fs_roots(fs_info);
2118 BUG_ON(ret);
2119
2120 ret = btrfs_recover_relocation(tree_root);
2121 if (ret < 0) {
2122 printk(KERN_WARNING
2123 "btrfs: failed to recover relocation\n");
2124 err = -EINVAL;
2125 goto fail_trans_kthread;
2126 }
2127 }
2128
2129 location.objectid = BTRFS_FS_TREE_OBJECTID;
2130 location.type = BTRFS_ROOT_ITEM_KEY;
2131 location.offset = (u64)-1;
2132
2133 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2134 if (!fs_info->fs_root)
2135 goto fail_trans_kthread;
2136 if (IS_ERR(fs_info->fs_root)) {
2137 err = PTR_ERR(fs_info->fs_root);
2138 goto fail_trans_kthread;
2139 }
2140
2141 if (!(sb->s_flags & MS_RDONLY)) {
2142 down_read(&fs_info->cleanup_work_sem);
2143 err = btrfs_orphan_cleanup(fs_info->fs_root);
2144 if (!err)
2145 err = btrfs_orphan_cleanup(fs_info->tree_root);
2146 up_read(&fs_info->cleanup_work_sem);
2147 if (err) {
2148 close_ctree(tree_root);
2149 return ERR_PTR(err);
2150 }
2151 }
2152
2153 return tree_root;
2154
2155fail_trans_kthread:
2156 kthread_stop(fs_info->transaction_kthread);
2157fail_cleaner:
2158 kthread_stop(fs_info->cleaner_kthread);
2159
2160 /*
2161 * make sure we're done with the btree inode before we stop our
2162 * kthreads
2163 */
2164 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2165 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2166
2167fail_block_groups:
2168 btrfs_free_block_groups(fs_info);
2169 free_extent_buffer(csum_root->node);
2170 free_extent_buffer(csum_root->commit_root);
2171fail_dev_root:
2172 free_extent_buffer(dev_root->node);
2173 free_extent_buffer(dev_root->commit_root);
2174fail_extent_root:
2175 free_extent_buffer(extent_root->node);
2176 free_extent_buffer(extent_root->commit_root);
2177fail_tree_root:
2178 free_extent_buffer(tree_root->node);
2179 free_extent_buffer(tree_root->commit_root);
2180fail_chunk_root:
2181 free_extent_buffer(chunk_root->node);
2182 free_extent_buffer(chunk_root->commit_root);
2183fail_sb_buffer:
2184 btrfs_stop_workers(&fs_info->generic_worker);
2185 btrfs_stop_workers(&fs_info->fixup_workers);
2186 btrfs_stop_workers(&fs_info->delalloc_workers);
2187 btrfs_stop_workers(&fs_info->workers);
2188 btrfs_stop_workers(&fs_info->endio_workers);
2189 btrfs_stop_workers(&fs_info->endio_meta_workers);
2190 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2191 btrfs_stop_workers(&fs_info->endio_write_workers);
2192 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2193 btrfs_stop_workers(&fs_info->submit_workers);
2194 btrfs_stop_workers(&fs_info->delayed_workers);
2195 btrfs_stop_workers(&fs_info->caching_workers);
2196fail_alloc:
2197 kfree(fs_info->delayed_root);
2198fail_iput:
2199 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2200 iput(fs_info->btree_inode);
2201
2202 btrfs_close_devices(fs_info->fs_devices);
2203 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2204fail_bdi:
2205 bdi_destroy(&fs_info->bdi);
2206fail_srcu:
2207 cleanup_srcu_struct(&fs_info->subvol_srcu);
2208fail:
2209 kfree(extent_root);
2210 kfree(tree_root);
2211 kfree(fs_info);
2212 kfree(chunk_root);
2213 kfree(dev_root);
2214 kfree(csum_root);
2215 return ERR_PTR(err);
2216}
2217
2218static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2219{
2220 char b[BDEVNAME_SIZE];
2221
2222 if (uptodate) {
2223 set_buffer_uptodate(bh);
2224 } else {
2225 printk_ratelimited(KERN_WARNING "lost page write due to "
2226 "I/O error on %s\n",
2227 bdevname(bh->b_bdev, b));
2228 /* note, we dont' set_buffer_write_io_error because we have
2229 * our own ways of dealing with the IO errors
2230 */
2231 clear_buffer_uptodate(bh);
2232 }
2233 unlock_buffer(bh);
2234 put_bh(bh);
2235}
2236
2237struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2238{
2239 struct buffer_head *bh;
2240 struct buffer_head *latest = NULL;
2241 struct btrfs_super_block *super;
2242 int i;
2243 u64 transid = 0;
2244 u64 bytenr;
2245
2246 /* we would like to check all the supers, but that would make
2247 * a btrfs mount succeed after a mkfs from a different FS.
2248 * So, we need to add a special mount option to scan for
2249 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2250 */
2251 for (i = 0; i < 1; i++) {
2252 bytenr = btrfs_sb_offset(i);
2253 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2254 break;
2255 bh = __bread(bdev, bytenr / 4096, 4096);
2256 if (!bh)
2257 continue;
2258
2259 super = (struct btrfs_super_block *)bh->b_data;
2260 if (btrfs_super_bytenr(super) != bytenr ||
2261 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2262 sizeof(super->magic))) {
2263 brelse(bh);
2264 continue;
2265 }
2266
2267 if (!latest || btrfs_super_generation(super) > transid) {
2268 brelse(latest);
2269 latest = bh;
2270 transid = btrfs_super_generation(super);
2271 } else {
2272 brelse(bh);
2273 }
2274 }
2275 return latest;
2276}
2277
2278/*
2279 * this should be called twice, once with wait == 0 and
2280 * once with wait == 1. When wait == 0 is done, all the buffer heads
2281 * we write are pinned.
2282 *
2283 * They are released when wait == 1 is done.
2284 * max_mirrors must be the same for both runs, and it indicates how
2285 * many supers on this one device should be written.
2286 *
2287 * max_mirrors == 0 means to write them all.
2288 */
2289static int write_dev_supers(struct btrfs_device *device,
2290 struct btrfs_super_block *sb,
2291 int do_barriers, int wait, int max_mirrors)
2292{
2293 struct buffer_head *bh;
2294 int i;
2295 int ret;
2296 int errors = 0;
2297 u32 crc;
2298 u64 bytenr;
2299 int last_barrier = 0;
2300
2301 if (max_mirrors == 0)
2302 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2303
2304 /* make sure only the last submit_bh does a barrier */
2305 if (do_barriers) {
2306 for (i = 0; i < max_mirrors; i++) {
2307 bytenr = btrfs_sb_offset(i);
2308 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2309 device->total_bytes)
2310 break;
2311 last_barrier = i;
2312 }
2313 }
2314
2315 for (i = 0; i < max_mirrors; i++) {
2316 bytenr = btrfs_sb_offset(i);
2317 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2318 break;
2319
2320 if (wait) {
2321 bh = __find_get_block(device->bdev, bytenr / 4096,
2322 BTRFS_SUPER_INFO_SIZE);
2323 BUG_ON(!bh);
2324 wait_on_buffer(bh);
2325 if (!buffer_uptodate(bh))
2326 errors++;
2327
2328 /* drop our reference */
2329 brelse(bh);
2330
2331 /* drop the reference from the wait == 0 run */
2332 brelse(bh);
2333 continue;
2334 } else {
2335 btrfs_set_super_bytenr(sb, bytenr);
2336
2337 crc = ~(u32)0;
2338 crc = btrfs_csum_data(NULL, (char *)sb +
2339 BTRFS_CSUM_SIZE, crc,
2340 BTRFS_SUPER_INFO_SIZE -
2341 BTRFS_CSUM_SIZE);
2342 btrfs_csum_final(crc, sb->csum);
2343
2344 /*
2345 * one reference for us, and we leave it for the
2346 * caller
2347 */
2348 bh = __getblk(device->bdev, bytenr / 4096,
2349 BTRFS_SUPER_INFO_SIZE);
2350 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2351
2352 /* one reference for submit_bh */
2353 get_bh(bh);
2354
2355 set_buffer_uptodate(bh);
2356 lock_buffer(bh);
2357 bh->b_end_io = btrfs_end_buffer_write_sync;
2358 }
2359
2360 if (i == last_barrier && do_barriers)
2361 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2362 else
2363 ret = submit_bh(WRITE_SYNC, bh);
2364
2365 if (ret)
2366 errors++;
2367 }
2368 return errors < i ? 0 : -1;
2369}
2370
2371int write_all_supers(struct btrfs_root *root, int max_mirrors)
2372{
2373 struct list_head *head;
2374 struct btrfs_device *dev;
2375 struct btrfs_super_block *sb;
2376 struct btrfs_dev_item *dev_item;
2377 int ret;
2378 int do_barriers;
2379 int max_errors;
2380 int total_errors = 0;
2381 u64 flags;
2382
2383 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2384 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2385
2386 sb = &root->fs_info->super_for_commit;
2387 dev_item = &sb->dev_item;
2388
2389 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2390 head = &root->fs_info->fs_devices->devices;
2391 list_for_each_entry_rcu(dev, head, dev_list) {
2392 if (!dev->bdev) {
2393 total_errors++;
2394 continue;
2395 }
2396 if (!dev->in_fs_metadata || !dev->writeable)
2397 continue;
2398
2399 btrfs_set_stack_device_generation(dev_item, 0);
2400 btrfs_set_stack_device_type(dev_item, dev->type);
2401 btrfs_set_stack_device_id(dev_item, dev->devid);
2402 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2403 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2404 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2405 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2406 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2407 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2408 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2409
2410 flags = btrfs_super_flags(sb);
2411 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2412
2413 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2414 if (ret)
2415 total_errors++;
2416 }
2417 if (total_errors > max_errors) {
2418 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2419 total_errors);
2420 BUG();
2421 }
2422
2423 total_errors = 0;
2424 list_for_each_entry_rcu(dev, head, dev_list) {
2425 if (!dev->bdev)
2426 continue;
2427 if (!dev->in_fs_metadata || !dev->writeable)
2428 continue;
2429
2430 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2431 if (ret)
2432 total_errors++;
2433 }
2434 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2435 if (total_errors > max_errors) {
2436 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2437 total_errors);
2438 BUG();
2439 }
2440 return 0;
2441}
2442
2443int write_ctree_super(struct btrfs_trans_handle *trans,
2444 struct btrfs_root *root, int max_mirrors)
2445{
2446 int ret;
2447
2448 ret = write_all_supers(root, max_mirrors);
2449 return ret;
2450}
2451
2452int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2453{
2454 spin_lock(&fs_info->fs_roots_radix_lock);
2455 radix_tree_delete(&fs_info->fs_roots_radix,
2456 (unsigned long)root->root_key.objectid);
2457 spin_unlock(&fs_info->fs_roots_radix_lock);
2458
2459 if (btrfs_root_refs(&root->root_item) == 0)
2460 synchronize_srcu(&fs_info->subvol_srcu);
2461
2462 __btrfs_remove_free_space_cache(root->free_ino_pinned);
2463 __btrfs_remove_free_space_cache(root->free_ino_ctl);
2464 free_fs_root(root);
2465 return 0;
2466}
2467
2468static void free_fs_root(struct btrfs_root *root)
2469{
2470 iput(root->cache_inode);
2471 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2472 if (root->anon_dev)
2473 free_anon_bdev(root->anon_dev);
2474 free_extent_buffer(root->node);
2475 free_extent_buffer(root->commit_root);
2476 kfree(root->free_ino_ctl);
2477 kfree(root->free_ino_pinned);
2478 kfree(root->name);
2479 kfree(root);
2480}
2481
2482static int del_fs_roots(struct btrfs_fs_info *fs_info)
2483{
2484 int ret;
2485 struct btrfs_root *gang[8];
2486 int i;
2487
2488 while (!list_empty(&fs_info->dead_roots)) {
2489 gang[0] = list_entry(fs_info->dead_roots.next,
2490 struct btrfs_root, root_list);
2491 list_del(&gang[0]->root_list);
2492
2493 if (gang[0]->in_radix) {
2494 btrfs_free_fs_root(fs_info, gang[0]);
2495 } else {
2496 free_extent_buffer(gang[0]->node);
2497 free_extent_buffer(gang[0]->commit_root);
2498 kfree(gang[0]);
2499 }
2500 }
2501
2502 while (1) {
2503 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2504 (void **)gang, 0,
2505 ARRAY_SIZE(gang));
2506 if (!ret)
2507 break;
2508 for (i = 0; i < ret; i++)
2509 btrfs_free_fs_root(fs_info, gang[i]);
2510 }
2511 return 0;
2512}
2513
2514int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2515{
2516 u64 root_objectid = 0;
2517 struct btrfs_root *gang[8];
2518 int i;
2519 int ret;
2520
2521 while (1) {
2522 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2523 (void **)gang, root_objectid,
2524 ARRAY_SIZE(gang));
2525 if (!ret)
2526 break;
2527
2528 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2529 for (i = 0; i < ret; i++) {
2530 int err;
2531
2532 root_objectid = gang[i]->root_key.objectid;
2533 err = btrfs_orphan_cleanup(gang[i]);
2534 if (err)
2535 return err;
2536 }
2537 root_objectid++;
2538 }
2539 return 0;
2540}
2541
2542int btrfs_commit_super(struct btrfs_root *root)
2543{
2544 struct btrfs_trans_handle *trans;
2545 int ret;
2546
2547 mutex_lock(&root->fs_info->cleaner_mutex);
2548 btrfs_run_delayed_iputs(root);
2549 btrfs_clean_old_snapshots(root);
2550 mutex_unlock(&root->fs_info->cleaner_mutex);
2551
2552 /* wait until ongoing cleanup work done */
2553 down_write(&root->fs_info->cleanup_work_sem);
2554 up_write(&root->fs_info->cleanup_work_sem);
2555
2556 trans = btrfs_join_transaction(root);
2557 if (IS_ERR(trans))
2558 return PTR_ERR(trans);
2559 ret = btrfs_commit_transaction(trans, root);
2560 BUG_ON(ret);
2561 /* run commit again to drop the original snapshot */
2562 trans = btrfs_join_transaction(root);
2563 if (IS_ERR(trans))
2564 return PTR_ERR(trans);
2565 btrfs_commit_transaction(trans, root);
2566 ret = btrfs_write_and_wait_transaction(NULL, root);
2567 BUG_ON(ret);
2568
2569 ret = write_ctree_super(NULL, root, 0);
2570 return ret;
2571}
2572
2573int close_ctree(struct btrfs_root *root)
2574{
2575 struct btrfs_fs_info *fs_info = root->fs_info;
2576 int ret;
2577
2578 fs_info->closing = 1;
2579 smp_mb();
2580
2581 btrfs_scrub_cancel(root);
2582
2583 /* wait for any defraggers to finish */
2584 wait_event(fs_info->transaction_wait,
2585 (atomic_read(&fs_info->defrag_running) == 0));
2586
2587 /* clear out the rbtree of defraggable inodes */
2588 btrfs_run_defrag_inodes(root->fs_info);
2589
2590 btrfs_put_block_group_cache(fs_info);
2591
2592 /*
2593 * Here come 2 situations when btrfs is broken to flip readonly:
2594 *
2595 * 1. when btrfs flips readonly somewhere else before
2596 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2597 * and btrfs will skip to write sb directly to keep
2598 * ERROR state on disk.
2599 *
2600 * 2. when btrfs flips readonly just in btrfs_commit_super,
2601 * and in such case, btrfs cannot write sb via btrfs_commit_super,
2602 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2603 * btrfs will cleanup all FS resources first and write sb then.
2604 */
2605 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2606 ret = btrfs_commit_super(root);
2607 if (ret)
2608 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2609 }
2610
2611 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2612 ret = btrfs_error_commit_super(root);
2613 if (ret)
2614 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2615 }
2616
2617 kthread_stop(root->fs_info->transaction_kthread);
2618 kthread_stop(root->fs_info->cleaner_kthread);
2619
2620 fs_info->closing = 2;
2621 smp_mb();
2622
2623 if (fs_info->delalloc_bytes) {
2624 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2625 (unsigned long long)fs_info->delalloc_bytes);
2626 }
2627 if (fs_info->total_ref_cache_size) {
2628 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2629 (unsigned long long)fs_info->total_ref_cache_size);
2630 }
2631
2632 free_extent_buffer(fs_info->extent_root->node);
2633 free_extent_buffer(fs_info->extent_root->commit_root);
2634 free_extent_buffer(fs_info->tree_root->node);
2635 free_extent_buffer(fs_info->tree_root->commit_root);
2636 free_extent_buffer(root->fs_info->chunk_root->node);
2637 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2638 free_extent_buffer(root->fs_info->dev_root->node);
2639 free_extent_buffer(root->fs_info->dev_root->commit_root);
2640 free_extent_buffer(root->fs_info->csum_root->node);
2641 free_extent_buffer(root->fs_info->csum_root->commit_root);
2642
2643 btrfs_free_block_groups(root->fs_info);
2644
2645 del_fs_roots(fs_info);
2646
2647 iput(fs_info->btree_inode);
2648 kfree(fs_info->delayed_root);
2649
2650 btrfs_stop_workers(&fs_info->generic_worker);
2651 btrfs_stop_workers(&fs_info->fixup_workers);
2652 btrfs_stop_workers(&fs_info->delalloc_workers);
2653 btrfs_stop_workers(&fs_info->workers);
2654 btrfs_stop_workers(&fs_info->endio_workers);
2655 btrfs_stop_workers(&fs_info->endio_meta_workers);
2656 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2657 btrfs_stop_workers(&fs_info->endio_write_workers);
2658 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2659 btrfs_stop_workers(&fs_info->submit_workers);
2660 btrfs_stop_workers(&fs_info->delayed_workers);
2661 btrfs_stop_workers(&fs_info->caching_workers);
2662 btrfs_stop_workers(&fs_info->readahead_workers);
2663
2664 btrfs_close_devices(fs_info->fs_devices);
2665 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2666
2667 bdi_destroy(&fs_info->bdi);
2668 cleanup_srcu_struct(&fs_info->subvol_srcu);
2669
2670 kfree(fs_info->extent_root);
2671 kfree(fs_info->tree_root);
2672 kfree(fs_info->chunk_root);
2673 kfree(fs_info->dev_root);
2674 kfree(fs_info->csum_root);
2675 kfree(fs_info);
2676
2677 return 0;
2678}
2679
2680int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2681{
2682 int ret;
2683 struct inode *btree_inode = buf->first_page->mapping->host;
2684
2685 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2686 NULL);
2687 if (!ret)
2688 return ret;
2689
2690 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2691 parent_transid);
2692 return !ret;
2693}
2694
2695int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2696{
2697 struct inode *btree_inode = buf->first_page->mapping->host;
2698 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2699 buf);
2700}
2701
2702void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2703{
2704 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2705 u64 transid = btrfs_header_generation(buf);
2706 struct inode *btree_inode = root->fs_info->btree_inode;
2707 int was_dirty;
2708
2709 btrfs_assert_tree_locked(buf);
2710 if (transid != root->fs_info->generation) {
2711 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2712 "found %llu running %llu\n",
2713 (unsigned long long)buf->start,
2714 (unsigned long long)transid,
2715 (unsigned long long)root->fs_info->generation);
2716 WARN_ON(1);
2717 }
2718 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2719 buf);
2720 if (!was_dirty) {
2721 spin_lock(&root->fs_info->delalloc_lock);
2722 root->fs_info->dirty_metadata_bytes += buf->len;
2723 spin_unlock(&root->fs_info->delalloc_lock);
2724 }
2725}
2726
2727void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2728{
2729 /*
2730 * looks as though older kernels can get into trouble with
2731 * this code, they end up stuck in balance_dirty_pages forever
2732 */
2733 u64 num_dirty;
2734 unsigned long thresh = 32 * 1024 * 1024;
2735
2736 if (current->flags & PF_MEMALLOC)
2737 return;
2738
2739 btrfs_balance_delayed_items(root);
2740
2741 num_dirty = root->fs_info->dirty_metadata_bytes;
2742
2743 if (num_dirty > thresh) {
2744 balance_dirty_pages_ratelimited_nr(
2745 root->fs_info->btree_inode->i_mapping, 1);
2746 }
2747 return;
2748}
2749
2750void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2751{
2752 /*
2753 * looks as though older kernels can get into trouble with
2754 * this code, they end up stuck in balance_dirty_pages forever
2755 */
2756 u64 num_dirty;
2757 unsigned long thresh = 32 * 1024 * 1024;
2758
2759 if (current->flags & PF_MEMALLOC)
2760 return;
2761
2762 num_dirty = root->fs_info->dirty_metadata_bytes;
2763
2764 if (num_dirty > thresh) {
2765 balance_dirty_pages_ratelimited_nr(
2766 root->fs_info->btree_inode->i_mapping, 1);
2767 }
2768 return;
2769}
2770
2771int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2772{
2773 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2774 int ret;
2775 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2776 if (ret == 0)
2777 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2778 return ret;
2779}
2780
2781int btree_lock_page_hook(struct page *page)
2782{
2783 struct inode *inode = page->mapping->host;
2784 struct btrfs_root *root = BTRFS_I(inode)->root;
2785 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2786 struct extent_buffer *eb;
2787 unsigned long len;
2788 u64 bytenr = page_offset(page);
2789
2790 if (page->private == EXTENT_PAGE_PRIVATE)
2791 goto out;
2792
2793 len = page->private >> 2;
2794 eb = find_extent_buffer(io_tree, bytenr, len);
2795 if (!eb)
2796 goto out;
2797
2798 btrfs_tree_lock(eb);
2799 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2800
2801 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2802 spin_lock(&root->fs_info->delalloc_lock);
2803 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2804 root->fs_info->dirty_metadata_bytes -= eb->len;
2805 else
2806 WARN_ON(1);
2807 spin_unlock(&root->fs_info->delalloc_lock);
2808 }
2809
2810 btrfs_tree_unlock(eb);
2811 free_extent_buffer(eb);
2812out:
2813 lock_page(page);
2814 return 0;
2815}
2816
2817static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2818 int read_only)
2819{
2820 if (read_only)
2821 return;
2822
2823 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2824 printk(KERN_WARNING "warning: mount fs with errors, "
2825 "running btrfsck is recommended\n");
2826}
2827
2828int btrfs_error_commit_super(struct btrfs_root *root)
2829{
2830 int ret;
2831
2832 mutex_lock(&root->fs_info->cleaner_mutex);
2833 btrfs_run_delayed_iputs(root);
2834 mutex_unlock(&root->fs_info->cleaner_mutex);
2835
2836 down_write(&root->fs_info->cleanup_work_sem);
2837 up_write(&root->fs_info->cleanup_work_sem);
2838
2839 /* cleanup FS via transaction */
2840 btrfs_cleanup_transaction(root);
2841
2842 ret = write_ctree_super(NULL, root, 0);
2843
2844 return ret;
2845}
2846
2847static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2848{
2849 struct btrfs_inode *btrfs_inode;
2850 struct list_head splice;
2851
2852 INIT_LIST_HEAD(&splice);
2853
2854 mutex_lock(&root->fs_info->ordered_operations_mutex);
2855 spin_lock(&root->fs_info->ordered_extent_lock);
2856
2857 list_splice_init(&root->fs_info->ordered_operations, &splice);
2858 while (!list_empty(&splice)) {
2859 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2860 ordered_operations);
2861
2862 list_del_init(&btrfs_inode->ordered_operations);
2863
2864 btrfs_invalidate_inodes(btrfs_inode->root);
2865 }
2866
2867 spin_unlock(&root->fs_info->ordered_extent_lock);
2868 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2869
2870 return 0;
2871}
2872
2873static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2874{
2875 struct list_head splice;
2876 struct btrfs_ordered_extent *ordered;
2877 struct inode *inode;
2878
2879 INIT_LIST_HEAD(&splice);
2880
2881 spin_lock(&root->fs_info->ordered_extent_lock);
2882
2883 list_splice_init(&root->fs_info->ordered_extents, &splice);
2884 while (!list_empty(&splice)) {
2885 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2886 root_extent_list);
2887
2888 list_del_init(&ordered->root_extent_list);
2889 atomic_inc(&ordered->refs);
2890
2891 /* the inode may be getting freed (in sys_unlink path). */
2892 inode = igrab(ordered->inode);
2893
2894 spin_unlock(&root->fs_info->ordered_extent_lock);
2895 if (inode)
2896 iput(inode);
2897
2898 atomic_set(&ordered->refs, 1);
2899 btrfs_put_ordered_extent(ordered);
2900
2901 spin_lock(&root->fs_info->ordered_extent_lock);
2902 }
2903
2904 spin_unlock(&root->fs_info->ordered_extent_lock);
2905
2906 return 0;
2907}
2908
2909static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2910 struct btrfs_root *root)
2911{
2912 struct rb_node *node;
2913 struct btrfs_delayed_ref_root *delayed_refs;
2914 struct btrfs_delayed_ref_node *ref;
2915 int ret = 0;
2916
2917 delayed_refs = &trans->delayed_refs;
2918
2919 spin_lock(&delayed_refs->lock);
2920 if (delayed_refs->num_entries == 0) {
2921 spin_unlock(&delayed_refs->lock);
2922 printk(KERN_INFO "delayed_refs has NO entry\n");
2923 return ret;
2924 }
2925
2926 node = rb_first(&delayed_refs->root);
2927 while (node) {
2928 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2929 node = rb_next(node);
2930
2931 ref->in_tree = 0;
2932 rb_erase(&ref->rb_node, &delayed_refs->root);
2933 delayed_refs->num_entries--;
2934
2935 atomic_set(&ref->refs, 1);
2936 if (btrfs_delayed_ref_is_head(ref)) {
2937 struct btrfs_delayed_ref_head *head;
2938
2939 head = btrfs_delayed_node_to_head(ref);
2940 mutex_lock(&head->mutex);
2941 kfree(head->extent_op);
2942 delayed_refs->num_heads--;
2943 if (list_empty(&head->cluster))
2944 delayed_refs->num_heads_ready--;
2945 list_del_init(&head->cluster);
2946 mutex_unlock(&head->mutex);
2947 }
2948
2949 spin_unlock(&delayed_refs->lock);
2950 btrfs_put_delayed_ref(ref);
2951
2952 cond_resched();
2953 spin_lock(&delayed_refs->lock);
2954 }
2955
2956 spin_unlock(&delayed_refs->lock);
2957
2958 return ret;
2959}
2960
2961static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2962{
2963 struct btrfs_pending_snapshot *snapshot;
2964 struct list_head splice;
2965
2966 INIT_LIST_HEAD(&splice);
2967
2968 list_splice_init(&t->pending_snapshots, &splice);
2969
2970 while (!list_empty(&splice)) {
2971 snapshot = list_entry(splice.next,
2972 struct btrfs_pending_snapshot,
2973 list);
2974
2975 list_del_init(&snapshot->list);
2976
2977 kfree(snapshot);
2978 }
2979
2980 return 0;
2981}
2982
2983static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2984{
2985 struct btrfs_inode *btrfs_inode;
2986 struct list_head splice;
2987
2988 INIT_LIST_HEAD(&splice);
2989
2990 spin_lock(&root->fs_info->delalloc_lock);
2991 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2992
2993 while (!list_empty(&splice)) {
2994 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2995 delalloc_inodes);
2996
2997 list_del_init(&btrfs_inode->delalloc_inodes);
2998
2999 btrfs_invalidate_inodes(btrfs_inode->root);
3000 }
3001
3002 spin_unlock(&root->fs_info->delalloc_lock);
3003
3004 return 0;
3005}
3006
3007static int btrfs_destroy_marked_extents(struct btrfs_root *root,
3008 struct extent_io_tree *dirty_pages,
3009 int mark)
3010{
3011 int ret;
3012 struct page *page;
3013 struct inode *btree_inode = root->fs_info->btree_inode;
3014 struct extent_buffer *eb;
3015 u64 start = 0;
3016 u64 end;
3017 u64 offset;
3018 unsigned long index;
3019
3020 while (1) {
3021 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
3022 mark);
3023 if (ret)
3024 break;
3025
3026 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
3027 while (start <= end) {
3028 index = start >> PAGE_CACHE_SHIFT;
3029 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
3030 page = find_get_page(btree_inode->i_mapping, index);
3031 if (!page)
3032 continue;
3033 offset = page_offset(page);
3034
3035 spin_lock(&dirty_pages->buffer_lock);
3036 eb = radix_tree_lookup(
3037 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
3038 offset >> PAGE_CACHE_SHIFT);
3039 spin_unlock(&dirty_pages->buffer_lock);
3040 if (eb) {
3041 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
3042 &eb->bflags);
3043 atomic_set(&eb->refs, 1);
3044 }
3045 if (PageWriteback(page))
3046 end_page_writeback(page);
3047
3048 lock_page(page);
3049 if (PageDirty(page)) {
3050 clear_page_dirty_for_io(page);
3051 spin_lock_irq(&page->mapping->tree_lock);
3052 radix_tree_tag_clear(&page->mapping->page_tree,
3053 page_index(page),
3054 PAGECACHE_TAG_DIRTY);
3055 spin_unlock_irq(&page->mapping->tree_lock);
3056 }
3057
3058 page->mapping->a_ops->invalidatepage(page, 0);
3059 unlock_page(page);
3060 }
3061 }
3062
3063 return ret;
3064}
3065
3066static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3067 struct extent_io_tree *pinned_extents)
3068{
3069 struct extent_io_tree *unpin;
3070 u64 start;
3071 u64 end;
3072 int ret;
3073
3074 unpin = pinned_extents;
3075 while (1) {
3076 ret = find_first_extent_bit(unpin, 0, &start, &end,
3077 EXTENT_DIRTY);
3078 if (ret)
3079 break;
3080
3081 /* opt_discard */
3082 if (btrfs_test_opt(root, DISCARD))
3083 ret = btrfs_error_discard_extent(root, start,
3084 end + 1 - start,
3085 NULL);
3086
3087 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3088 btrfs_error_unpin_extent_range(root, start, end);
3089 cond_resched();
3090 }
3091
3092 return 0;
3093}
3094
3095static int btrfs_cleanup_transaction(struct btrfs_root *root)
3096{
3097 struct btrfs_transaction *t;
3098 LIST_HEAD(list);
3099
3100 WARN_ON(1);
3101
3102 mutex_lock(&root->fs_info->transaction_kthread_mutex);
3103
3104 spin_lock(&root->fs_info->trans_lock);
3105 list_splice_init(&root->fs_info->trans_list, &list);
3106 root->fs_info->trans_no_join = 1;
3107 spin_unlock(&root->fs_info->trans_lock);
3108
3109 while (!list_empty(&list)) {
3110 t = list_entry(list.next, struct btrfs_transaction, list);
3111 if (!t)
3112 break;
3113
3114 btrfs_destroy_ordered_operations(root);
3115
3116 btrfs_destroy_ordered_extents(root);
3117
3118 btrfs_destroy_delayed_refs(t, root);
3119
3120 btrfs_block_rsv_release(root,
3121 &root->fs_info->trans_block_rsv,
3122 t->dirty_pages.dirty_bytes);
3123
3124 /* FIXME: cleanup wait for commit */
3125 t->in_commit = 1;
3126 t->blocked = 1;
3127 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3128 wake_up(&root->fs_info->transaction_blocked_wait);
3129
3130 t->blocked = 0;
3131 if (waitqueue_active(&root->fs_info->transaction_wait))
3132 wake_up(&root->fs_info->transaction_wait);
3133
3134 t->commit_done = 1;
3135 if (waitqueue_active(&t->commit_wait))
3136 wake_up(&t->commit_wait);
3137
3138 btrfs_destroy_pending_snapshots(t);
3139
3140 btrfs_destroy_delalloc_inodes(root);
3141
3142 spin_lock(&root->fs_info->trans_lock);
3143 root->fs_info->running_transaction = NULL;
3144 spin_unlock(&root->fs_info->trans_lock);
3145
3146 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3147 EXTENT_DIRTY);
3148
3149 btrfs_destroy_pinned_extent(root,
3150 root->fs_info->pinned_extents);
3151
3152 atomic_set(&t->use_count, 0);
3153 list_del_init(&t->list);
3154 memset(t, 0, sizeof(*t));
3155 kmem_cache_free(btrfs_transaction_cachep, t);
3156 }
3157
3158 spin_lock(&root->fs_info->trans_lock);
3159 root->fs_info->trans_no_join = 0;
3160 spin_unlock(&root->fs_info->trans_lock);
3161 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3162
3163 return 0;
3164}
3165
3166static struct extent_io_ops btree_extent_io_ops = {
3167 .write_cache_pages_lock_hook = btree_lock_page_hook,
3168 .readpage_end_io_hook = btree_readpage_end_io_hook,
3169 .submit_bio_hook = btree_submit_bio_hook,
3170 /* note we're sharing with inode.c for the merge bio hook */
3171 .merge_bio_hook = btrfs_merge_bio_hook,
3172};
Linux kernel - Deliverables
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