xref: /linux/fs/btrfs/disk-io.c (revision d0f482bb06f9447d44d2cae0386a0bd768c3cc16)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #include <linux/fs.h>
7 #include <linux/blkdev.h>
8 #include <linux/radix-tree.h>
9 #include <linux/writeback.h>
10 #include <linux/workqueue.h>
11 #include <linux/kthread.h>
12 #include <linux/slab.h>
13 #include <linux/migrate.h>
14 #include <linux/ratelimit.h>
15 #include <linux/uuid.h>
16 #include <linux/semaphore.h>
17 #include <linux/error-injection.h>
18 #include <linux/crc32c.h>
19 #include <linux/sched/mm.h>
20 #include <asm/unaligned.h>
21 #include <crypto/hash.h>
22 #include "ctree.h"
23 #include "disk-io.h"
24 #include "transaction.h"
25 #include "btrfs_inode.h"
26 #include "volumes.h"
27 #include "print-tree.h"
28 #include "locking.h"
29 #include "tree-log.h"
30 #include "free-space-cache.h"
31 #include "free-space-tree.h"
32 #include "check-integrity.h"
33 #include "rcu-string.h"
34 #include "dev-replace.h"
35 #include "raid56.h"
36 #include "sysfs.h"
37 #include "qgroup.h"
38 #include "compression.h"
39 #include "tree-checker.h"
40 #include "ref-verify.h"
41 #include "block-group.h"
42 #include "discard.h"
43 #include "space-info.h"
44 #include "zoned.h"
45 #include "subpage.h"
46 
47 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN |\
48 				 BTRFS_HEADER_FLAG_RELOC |\
49 				 BTRFS_SUPER_FLAG_ERROR |\
50 				 BTRFS_SUPER_FLAG_SEEDING |\
51 				 BTRFS_SUPER_FLAG_METADUMP |\
52 				 BTRFS_SUPER_FLAG_METADUMP_V2)
53 
54 static void end_workqueue_fn(struct btrfs_work *work);
55 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
56 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
57 				      struct btrfs_fs_info *fs_info);
58 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
59 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
60 					struct extent_io_tree *dirty_pages,
61 					int mark);
62 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
63 				       struct extent_io_tree *pinned_extents);
64 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
65 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
66 
67 /*
68  * btrfs_end_io_wq structs are used to do processing in task context when an IO
69  * is complete.  This is used during reads to verify checksums, and it is used
70  * by writes to insert metadata for new file extents after IO is complete.
71  */
72 struct btrfs_end_io_wq {
73 	struct bio *bio;
74 	bio_end_io_t *end_io;
75 	void *private;
76 	struct btrfs_fs_info *info;
77 	blk_status_t status;
78 	enum btrfs_wq_endio_type metadata;
79 	struct btrfs_work work;
80 };
81 
82 static struct kmem_cache *btrfs_end_io_wq_cache;
83 
84 int __init btrfs_end_io_wq_init(void)
85 {
86 	btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
87 					sizeof(struct btrfs_end_io_wq),
88 					0,
89 					SLAB_MEM_SPREAD,
90 					NULL);
91 	if (!btrfs_end_io_wq_cache)
92 		return -ENOMEM;
93 	return 0;
94 }
95 
96 void __cold btrfs_end_io_wq_exit(void)
97 {
98 	kmem_cache_destroy(btrfs_end_io_wq_cache);
99 }
100 
101 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
102 {
103 	if (fs_info->csum_shash)
104 		crypto_free_shash(fs_info->csum_shash);
105 }
106 
107 /*
108  * async submit bios are used to offload expensive checksumming
109  * onto the worker threads.  They checksum file and metadata bios
110  * just before they are sent down the IO stack.
111  */
112 struct async_submit_bio {
113 	struct inode *inode;
114 	struct bio *bio;
115 	extent_submit_bio_start_t *submit_bio_start;
116 	int mirror_num;
117 
118 	/* Optional parameter for submit_bio_start used by direct io */
119 	u64 dio_file_offset;
120 	struct btrfs_work work;
121 	blk_status_t status;
122 };
123 
124 /*
125  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
126  * eb, the lockdep key is determined by the btrfs_root it belongs to and
127  * the level the eb occupies in the tree.
128  *
129  * Different roots are used for different purposes and may nest inside each
130  * other and they require separate keysets.  As lockdep keys should be
131  * static, assign keysets according to the purpose of the root as indicated
132  * by btrfs_root->root_key.objectid.  This ensures that all special purpose
133  * roots have separate keysets.
134  *
135  * Lock-nesting across peer nodes is always done with the immediate parent
136  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
137  * subclass to avoid triggering lockdep warning in such cases.
138  *
139  * The key is set by the readpage_end_io_hook after the buffer has passed
140  * csum validation but before the pages are unlocked.  It is also set by
141  * btrfs_init_new_buffer on freshly allocated blocks.
142  *
143  * We also add a check to make sure the highest level of the tree is the
144  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
145  * needs update as well.
146  */
147 #ifdef CONFIG_DEBUG_LOCK_ALLOC
148 # if BTRFS_MAX_LEVEL != 8
149 #  error
150 # endif
151 
152 #define DEFINE_LEVEL(stem, level)					\
153 	.names[level] = "btrfs-" stem "-0" #level,
154 
155 #define DEFINE_NAME(stem)						\
156 	DEFINE_LEVEL(stem, 0)						\
157 	DEFINE_LEVEL(stem, 1)						\
158 	DEFINE_LEVEL(stem, 2)						\
159 	DEFINE_LEVEL(stem, 3)						\
160 	DEFINE_LEVEL(stem, 4)						\
161 	DEFINE_LEVEL(stem, 5)						\
162 	DEFINE_LEVEL(stem, 6)						\
163 	DEFINE_LEVEL(stem, 7)
164 
165 static struct btrfs_lockdep_keyset {
166 	u64			id;		/* root objectid */
167 	/* Longest entry: btrfs-free-space-00 */
168 	char			names[BTRFS_MAX_LEVEL][20];
169 	struct lock_class_key	keys[BTRFS_MAX_LEVEL];
170 } btrfs_lockdep_keysets[] = {
171 	{ .id = BTRFS_ROOT_TREE_OBJECTID,	DEFINE_NAME("root")	},
172 	{ .id = BTRFS_EXTENT_TREE_OBJECTID,	DEFINE_NAME("extent")	},
173 	{ .id = BTRFS_CHUNK_TREE_OBJECTID,	DEFINE_NAME("chunk")	},
174 	{ .id = BTRFS_DEV_TREE_OBJECTID,	DEFINE_NAME("dev")	},
175 	{ .id = BTRFS_CSUM_TREE_OBJECTID,	DEFINE_NAME("csum")	},
176 	{ .id = BTRFS_QUOTA_TREE_OBJECTID,	DEFINE_NAME("quota")	},
177 	{ .id = BTRFS_TREE_LOG_OBJECTID,	DEFINE_NAME("log")	},
178 	{ .id = BTRFS_TREE_RELOC_OBJECTID,	DEFINE_NAME("treloc")	},
179 	{ .id = BTRFS_DATA_RELOC_TREE_OBJECTID,	DEFINE_NAME("dreloc")	},
180 	{ .id = BTRFS_UUID_TREE_OBJECTID,	DEFINE_NAME("uuid")	},
181 	{ .id = BTRFS_FREE_SPACE_TREE_OBJECTID,	DEFINE_NAME("free-space") },
182 	{ .id = 0,				DEFINE_NAME("tree")	},
183 };
184 
185 #undef DEFINE_LEVEL
186 #undef DEFINE_NAME
187 
188 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
189 				    int level)
190 {
191 	struct btrfs_lockdep_keyset *ks;
192 
193 	BUG_ON(level >= ARRAY_SIZE(ks->keys));
194 
195 	/* find the matching keyset, id 0 is the default entry */
196 	for (ks = btrfs_lockdep_keysets; ks->id; ks++)
197 		if (ks->id == objectid)
198 			break;
199 
200 	lockdep_set_class_and_name(&eb->lock,
201 				   &ks->keys[level], ks->names[level]);
202 }
203 
204 #endif
205 
206 /*
207  * Compute the csum of a btree block and store the result to provided buffer.
208  */
209 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
210 {
211 	struct btrfs_fs_info *fs_info = buf->fs_info;
212 	const int num_pages = fs_info->nodesize >> PAGE_SHIFT;
213 	const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
214 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
215 	char *kaddr;
216 	int i;
217 
218 	shash->tfm = fs_info->csum_shash;
219 	crypto_shash_init(shash);
220 	kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start);
221 	crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
222 			    first_page_part - BTRFS_CSUM_SIZE);
223 
224 	for (i = 1; i < num_pages; i++) {
225 		kaddr = page_address(buf->pages[i]);
226 		crypto_shash_update(shash, kaddr, PAGE_SIZE);
227 	}
228 	memset(result, 0, BTRFS_CSUM_SIZE);
229 	crypto_shash_final(shash, result);
230 }
231 
232 /*
233  * we can't consider a given block up to date unless the transid of the
234  * block matches the transid in the parent node's pointer.  This is how we
235  * detect blocks that either didn't get written at all or got written
236  * in the wrong place.
237  */
238 static int verify_parent_transid(struct extent_io_tree *io_tree,
239 				 struct extent_buffer *eb, u64 parent_transid,
240 				 int atomic)
241 {
242 	struct extent_state *cached_state = NULL;
243 	int ret;
244 	bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
245 
246 	if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
247 		return 0;
248 
249 	if (atomic)
250 		return -EAGAIN;
251 
252 	if (need_lock)
253 		btrfs_tree_read_lock(eb);
254 
255 	lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
256 			 &cached_state);
257 	if (extent_buffer_uptodate(eb) &&
258 	    btrfs_header_generation(eb) == parent_transid) {
259 		ret = 0;
260 		goto out;
261 	}
262 	btrfs_err_rl(eb->fs_info,
263 		"parent transid verify failed on %llu wanted %llu found %llu",
264 			eb->start,
265 			parent_transid, btrfs_header_generation(eb));
266 	ret = 1;
267 
268 	/*
269 	 * Things reading via commit roots that don't have normal protection,
270 	 * like send, can have a really old block in cache that may point at a
271 	 * block that has been freed and re-allocated.  So don't clear uptodate
272 	 * if we find an eb that is under IO (dirty/writeback) because we could
273 	 * end up reading in the stale data and then writing it back out and
274 	 * making everybody very sad.
275 	 */
276 	if (!extent_buffer_under_io(eb))
277 		clear_extent_buffer_uptodate(eb);
278 out:
279 	unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
280 			     &cached_state);
281 	if (need_lock)
282 		btrfs_tree_read_unlock(eb);
283 	return ret;
284 }
285 
286 static bool btrfs_supported_super_csum(u16 csum_type)
287 {
288 	switch (csum_type) {
289 	case BTRFS_CSUM_TYPE_CRC32:
290 	case BTRFS_CSUM_TYPE_XXHASH:
291 	case BTRFS_CSUM_TYPE_SHA256:
292 	case BTRFS_CSUM_TYPE_BLAKE2:
293 		return true;
294 	default:
295 		return false;
296 	}
297 }
298 
299 /*
300  * Return 0 if the superblock checksum type matches the checksum value of that
301  * algorithm. Pass the raw disk superblock data.
302  */
303 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
304 				  char *raw_disk_sb)
305 {
306 	struct btrfs_super_block *disk_sb =
307 		(struct btrfs_super_block *)raw_disk_sb;
308 	char result[BTRFS_CSUM_SIZE];
309 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
310 
311 	shash->tfm = fs_info->csum_shash;
312 
313 	/*
314 	 * The super_block structure does not span the whole
315 	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
316 	 * filled with zeros and is included in the checksum.
317 	 */
318 	crypto_shash_digest(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
319 			    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
320 
321 	if (memcmp(disk_sb->csum, result, fs_info->csum_size))
322 		return 1;
323 
324 	return 0;
325 }
326 
327 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
328 			   struct btrfs_key *first_key, u64 parent_transid)
329 {
330 	struct btrfs_fs_info *fs_info = eb->fs_info;
331 	int found_level;
332 	struct btrfs_key found_key;
333 	int ret;
334 
335 	found_level = btrfs_header_level(eb);
336 	if (found_level != level) {
337 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
338 		     KERN_ERR "BTRFS: tree level check failed\n");
339 		btrfs_err(fs_info,
340 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
341 			  eb->start, level, found_level);
342 		return -EIO;
343 	}
344 
345 	if (!first_key)
346 		return 0;
347 
348 	/*
349 	 * For live tree block (new tree blocks in current transaction),
350 	 * we need proper lock context to avoid race, which is impossible here.
351 	 * So we only checks tree blocks which is read from disk, whose
352 	 * generation <= fs_info->last_trans_committed.
353 	 */
354 	if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
355 		return 0;
356 
357 	/* We have @first_key, so this @eb must have at least one item */
358 	if (btrfs_header_nritems(eb) == 0) {
359 		btrfs_err(fs_info,
360 		"invalid tree nritems, bytenr=%llu nritems=0 expect >0",
361 			  eb->start);
362 		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
363 		return -EUCLEAN;
364 	}
365 
366 	if (found_level)
367 		btrfs_node_key_to_cpu(eb, &found_key, 0);
368 	else
369 		btrfs_item_key_to_cpu(eb, &found_key, 0);
370 	ret = btrfs_comp_cpu_keys(first_key, &found_key);
371 
372 	if (ret) {
373 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
374 		     KERN_ERR "BTRFS: tree first key check failed\n");
375 		btrfs_err(fs_info,
376 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
377 			  eb->start, parent_transid, first_key->objectid,
378 			  first_key->type, first_key->offset,
379 			  found_key.objectid, found_key.type,
380 			  found_key.offset);
381 	}
382 	return ret;
383 }
384 
385 /*
386  * helper to read a given tree block, doing retries as required when
387  * the checksums don't match and we have alternate mirrors to try.
388  *
389  * @parent_transid:	expected transid, skip check if 0
390  * @level:		expected level, mandatory check
391  * @first_key:		expected key of first slot, skip check if NULL
392  */
393 static int btree_read_extent_buffer_pages(struct extent_buffer *eb,
394 					  u64 parent_transid, int level,
395 					  struct btrfs_key *first_key)
396 {
397 	struct btrfs_fs_info *fs_info = eb->fs_info;
398 	struct extent_io_tree *io_tree;
399 	int failed = 0;
400 	int ret;
401 	int num_copies = 0;
402 	int mirror_num = 0;
403 	int failed_mirror = 0;
404 
405 	io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
406 	while (1) {
407 		clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
408 		ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num);
409 		if (!ret) {
410 			if (verify_parent_transid(io_tree, eb,
411 						   parent_transid, 0))
412 				ret = -EIO;
413 			else if (btrfs_verify_level_key(eb, level,
414 						first_key, parent_transid))
415 				ret = -EUCLEAN;
416 			else
417 				break;
418 		}
419 
420 		num_copies = btrfs_num_copies(fs_info,
421 					      eb->start, eb->len);
422 		if (num_copies == 1)
423 			break;
424 
425 		if (!failed_mirror) {
426 			failed = 1;
427 			failed_mirror = eb->read_mirror;
428 		}
429 
430 		mirror_num++;
431 		if (mirror_num == failed_mirror)
432 			mirror_num++;
433 
434 		if (mirror_num > num_copies)
435 			break;
436 	}
437 
438 	if (failed && !ret && failed_mirror)
439 		btrfs_repair_eb_io_failure(eb, failed_mirror);
440 
441 	return ret;
442 }
443 
444 static int csum_one_extent_buffer(struct extent_buffer *eb)
445 {
446 	struct btrfs_fs_info *fs_info = eb->fs_info;
447 	u8 result[BTRFS_CSUM_SIZE];
448 	int ret;
449 
450 	ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
451 				    offsetof(struct btrfs_header, fsid),
452 				    BTRFS_FSID_SIZE) == 0);
453 	csum_tree_block(eb, result);
454 
455 	if (btrfs_header_level(eb))
456 		ret = btrfs_check_node(eb);
457 	else
458 		ret = btrfs_check_leaf_full(eb);
459 
460 	if (ret < 0) {
461 		btrfs_print_tree(eb, 0);
462 		btrfs_err(fs_info,
463 			"block=%llu write time tree block corruption detected",
464 			eb->start);
465 		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
466 		return ret;
467 	}
468 	write_extent_buffer(eb, result, 0, fs_info->csum_size);
469 
470 	return 0;
471 }
472 
473 /* Checksum all dirty extent buffers in one bio_vec */
474 static int csum_dirty_subpage_buffers(struct btrfs_fs_info *fs_info,
475 				      struct bio_vec *bvec)
476 {
477 	struct page *page = bvec->bv_page;
478 	u64 bvec_start = page_offset(page) + bvec->bv_offset;
479 	u64 cur;
480 	int ret = 0;
481 
482 	for (cur = bvec_start; cur < bvec_start + bvec->bv_len;
483 	     cur += fs_info->nodesize) {
484 		struct extent_buffer *eb;
485 		bool uptodate;
486 
487 		eb = find_extent_buffer(fs_info, cur);
488 		uptodate = btrfs_subpage_test_uptodate(fs_info, page, cur,
489 						       fs_info->nodesize);
490 
491 		/* A dirty eb shouldn't disappear from buffer_radix */
492 		if (WARN_ON(!eb))
493 			return -EUCLEAN;
494 
495 		if (WARN_ON(cur != btrfs_header_bytenr(eb))) {
496 			free_extent_buffer(eb);
497 			return -EUCLEAN;
498 		}
499 		if (WARN_ON(!uptodate)) {
500 			free_extent_buffer(eb);
501 			return -EUCLEAN;
502 		}
503 
504 		ret = csum_one_extent_buffer(eb);
505 		free_extent_buffer(eb);
506 		if (ret < 0)
507 			return ret;
508 	}
509 	return ret;
510 }
511 
512 /*
513  * Checksum a dirty tree block before IO.  This has extra checks to make sure
514  * we only fill in the checksum field in the first page of a multi-page block.
515  * For subpage extent buffers we need bvec to also read the offset in the page.
516  */
517 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct bio_vec *bvec)
518 {
519 	struct page *page = bvec->bv_page;
520 	u64 start = page_offset(page);
521 	u64 found_start;
522 	struct extent_buffer *eb;
523 
524 	if (fs_info->sectorsize < PAGE_SIZE)
525 		return csum_dirty_subpage_buffers(fs_info, bvec);
526 
527 	eb = (struct extent_buffer *)page->private;
528 	if (page != eb->pages[0])
529 		return 0;
530 
531 	found_start = btrfs_header_bytenr(eb);
532 
533 	if (test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)) {
534 		WARN_ON(found_start != 0);
535 		return 0;
536 	}
537 
538 	/*
539 	 * Please do not consolidate these warnings into a single if.
540 	 * It is useful to know what went wrong.
541 	 */
542 	if (WARN_ON(found_start != start))
543 		return -EUCLEAN;
544 	if (WARN_ON(!PageUptodate(page)))
545 		return -EUCLEAN;
546 
547 	return csum_one_extent_buffer(eb);
548 }
549 
550 static int check_tree_block_fsid(struct extent_buffer *eb)
551 {
552 	struct btrfs_fs_info *fs_info = eb->fs_info;
553 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
554 	u8 fsid[BTRFS_FSID_SIZE];
555 	u8 *metadata_uuid;
556 
557 	read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
558 			   BTRFS_FSID_SIZE);
559 	/*
560 	 * Checking the incompat flag is only valid for the current fs. For
561 	 * seed devices it's forbidden to have their uuid changed so reading
562 	 * ->fsid in this case is fine
563 	 */
564 	if (btrfs_fs_incompat(fs_info, METADATA_UUID))
565 		metadata_uuid = fs_devices->metadata_uuid;
566 	else
567 		metadata_uuid = fs_devices->fsid;
568 
569 	if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
570 		return 0;
571 
572 	list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
573 		if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
574 			return 0;
575 
576 	return 1;
577 }
578 
579 /* Do basic extent buffer checks at read time */
580 static int validate_extent_buffer(struct extent_buffer *eb)
581 {
582 	struct btrfs_fs_info *fs_info = eb->fs_info;
583 	u64 found_start;
584 	const u32 csum_size = fs_info->csum_size;
585 	u8 found_level;
586 	u8 result[BTRFS_CSUM_SIZE];
587 	int ret = 0;
588 
589 	found_start = btrfs_header_bytenr(eb);
590 	if (found_start != eb->start) {
591 		btrfs_err_rl(fs_info, "bad tree block start, want %llu have %llu",
592 			     eb->start, found_start);
593 		ret = -EIO;
594 		goto out;
595 	}
596 	if (check_tree_block_fsid(eb)) {
597 		btrfs_err_rl(fs_info, "bad fsid on block %llu",
598 			     eb->start);
599 		ret = -EIO;
600 		goto out;
601 	}
602 	found_level = btrfs_header_level(eb);
603 	if (found_level >= BTRFS_MAX_LEVEL) {
604 		btrfs_err(fs_info, "bad tree block level %d on %llu",
605 			  (int)btrfs_header_level(eb), eb->start);
606 		ret = -EIO;
607 		goto out;
608 	}
609 
610 	csum_tree_block(eb, result);
611 
612 	if (memcmp_extent_buffer(eb, result, 0, csum_size)) {
613 		u8 val[BTRFS_CSUM_SIZE] = { 0 };
614 
615 		read_extent_buffer(eb, &val, 0, csum_size);
616 		btrfs_warn_rl(fs_info,
617 	"%s checksum verify failed on %llu wanted " CSUM_FMT " found " CSUM_FMT " level %d",
618 			      fs_info->sb->s_id, eb->start,
619 			      CSUM_FMT_VALUE(csum_size, val),
620 			      CSUM_FMT_VALUE(csum_size, result),
621 			      btrfs_header_level(eb));
622 		ret = -EUCLEAN;
623 		goto out;
624 	}
625 
626 	/*
627 	 * If this is a leaf block and it is corrupt, set the corrupt bit so
628 	 * that we don't try and read the other copies of this block, just
629 	 * return -EIO.
630 	 */
631 	if (found_level == 0 && btrfs_check_leaf_full(eb)) {
632 		set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
633 		ret = -EIO;
634 	}
635 
636 	if (found_level > 0 && btrfs_check_node(eb))
637 		ret = -EIO;
638 
639 	if (!ret)
640 		set_extent_buffer_uptodate(eb);
641 	else
642 		btrfs_err(fs_info,
643 			  "block=%llu read time tree block corruption detected",
644 			  eb->start);
645 out:
646 	return ret;
647 }
648 
649 static int validate_subpage_buffer(struct page *page, u64 start, u64 end,
650 				   int mirror)
651 {
652 	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
653 	struct extent_buffer *eb;
654 	bool reads_done;
655 	int ret = 0;
656 
657 	/*
658 	 * We don't allow bio merge for subpage metadata read, so we should
659 	 * only get one eb for each endio hook.
660 	 */
661 	ASSERT(end == start + fs_info->nodesize - 1);
662 	ASSERT(PagePrivate(page));
663 
664 	eb = find_extent_buffer(fs_info, start);
665 	/*
666 	 * When we are reading one tree block, eb must have been inserted into
667 	 * the radix tree. If not, something is wrong.
668 	 */
669 	ASSERT(eb);
670 
671 	reads_done = atomic_dec_and_test(&eb->io_pages);
672 	/* Subpage read must finish in page read */
673 	ASSERT(reads_done);
674 
675 	eb->read_mirror = mirror;
676 	if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
677 		ret = -EIO;
678 		goto err;
679 	}
680 	ret = validate_extent_buffer(eb);
681 	if (ret < 0)
682 		goto err;
683 
684 	if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
685 		btree_readahead_hook(eb, ret);
686 
687 	set_extent_buffer_uptodate(eb);
688 
689 	free_extent_buffer(eb);
690 	return ret;
691 err:
692 	/*
693 	 * end_bio_extent_readpage decrements io_pages in case of error,
694 	 * make sure it has something to decrement.
695 	 */
696 	atomic_inc(&eb->io_pages);
697 	clear_extent_buffer_uptodate(eb);
698 	free_extent_buffer(eb);
699 	return ret;
700 }
701 
702 int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio,
703 				   struct page *page, u64 start, u64 end,
704 				   int mirror)
705 {
706 	struct extent_buffer *eb;
707 	int ret = 0;
708 	int reads_done;
709 
710 	ASSERT(page->private);
711 
712 	if (btrfs_sb(page->mapping->host->i_sb)->sectorsize < PAGE_SIZE)
713 		return validate_subpage_buffer(page, start, end, mirror);
714 
715 	eb = (struct extent_buffer *)page->private;
716 
717 	/*
718 	 * The pending IO might have been the only thing that kept this buffer
719 	 * in memory.  Make sure we have a ref for all this other checks
720 	 */
721 	atomic_inc(&eb->refs);
722 
723 	reads_done = atomic_dec_and_test(&eb->io_pages);
724 	if (!reads_done)
725 		goto err;
726 
727 	eb->read_mirror = mirror;
728 	if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
729 		ret = -EIO;
730 		goto err;
731 	}
732 	ret = validate_extent_buffer(eb);
733 err:
734 	if (reads_done &&
735 	    test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
736 		btree_readahead_hook(eb, ret);
737 
738 	if (ret) {
739 		/*
740 		 * our io error hook is going to dec the io pages
741 		 * again, we have to make sure it has something
742 		 * to decrement
743 		 */
744 		atomic_inc(&eb->io_pages);
745 		clear_extent_buffer_uptodate(eb);
746 	}
747 	free_extent_buffer(eb);
748 
749 	return ret;
750 }
751 
752 static void end_workqueue_bio(struct bio *bio)
753 {
754 	struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
755 	struct btrfs_fs_info *fs_info;
756 	struct btrfs_workqueue *wq;
757 
758 	fs_info = end_io_wq->info;
759 	end_io_wq->status = bio->bi_status;
760 
761 	if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
762 		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
763 			wq = fs_info->endio_meta_write_workers;
764 		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
765 			wq = fs_info->endio_freespace_worker;
766 		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
767 			wq = fs_info->endio_raid56_workers;
768 		else
769 			wq = fs_info->endio_write_workers;
770 	} else {
771 		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
772 			wq = fs_info->endio_raid56_workers;
773 		else if (end_io_wq->metadata)
774 			wq = fs_info->endio_meta_workers;
775 		else
776 			wq = fs_info->endio_workers;
777 	}
778 
779 	btrfs_init_work(&end_io_wq->work, end_workqueue_fn, NULL, NULL);
780 	btrfs_queue_work(wq, &end_io_wq->work);
781 }
782 
783 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
784 			enum btrfs_wq_endio_type metadata)
785 {
786 	struct btrfs_end_io_wq *end_io_wq;
787 
788 	end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
789 	if (!end_io_wq)
790 		return BLK_STS_RESOURCE;
791 
792 	end_io_wq->private = bio->bi_private;
793 	end_io_wq->end_io = bio->bi_end_io;
794 	end_io_wq->info = info;
795 	end_io_wq->status = 0;
796 	end_io_wq->bio = bio;
797 	end_io_wq->metadata = metadata;
798 
799 	bio->bi_private = end_io_wq;
800 	bio->bi_end_io = end_workqueue_bio;
801 	return 0;
802 }
803 
804 static void run_one_async_start(struct btrfs_work *work)
805 {
806 	struct async_submit_bio *async;
807 	blk_status_t ret;
808 
809 	async = container_of(work, struct  async_submit_bio, work);
810 	ret = async->submit_bio_start(async->inode, async->bio,
811 				      async->dio_file_offset);
812 	if (ret)
813 		async->status = ret;
814 }
815 
816 /*
817  * In order to insert checksums into the metadata in large chunks, we wait
818  * until bio submission time.   All the pages in the bio are checksummed and
819  * sums are attached onto the ordered extent record.
820  *
821  * At IO completion time the csums attached on the ordered extent record are
822  * inserted into the tree.
823  */
824 static void run_one_async_done(struct btrfs_work *work)
825 {
826 	struct async_submit_bio *async;
827 	struct inode *inode;
828 	blk_status_t ret;
829 
830 	async = container_of(work, struct  async_submit_bio, work);
831 	inode = async->inode;
832 
833 	/* If an error occurred we just want to clean up the bio and move on */
834 	if (async->status) {
835 		async->bio->bi_status = async->status;
836 		bio_endio(async->bio);
837 		return;
838 	}
839 
840 	/*
841 	 * All of the bios that pass through here are from async helpers.
842 	 * Use REQ_CGROUP_PUNT to issue them from the owning cgroup's context.
843 	 * This changes nothing when cgroups aren't in use.
844 	 */
845 	async->bio->bi_opf |= REQ_CGROUP_PUNT;
846 	ret = btrfs_map_bio(btrfs_sb(inode->i_sb), async->bio, async->mirror_num);
847 	if (ret) {
848 		async->bio->bi_status = ret;
849 		bio_endio(async->bio);
850 	}
851 }
852 
853 static void run_one_async_free(struct btrfs_work *work)
854 {
855 	struct async_submit_bio *async;
856 
857 	async = container_of(work, struct  async_submit_bio, work);
858 	kfree(async);
859 }
860 
861 blk_status_t btrfs_wq_submit_bio(struct inode *inode, struct bio *bio,
862 				 int mirror_num, unsigned long bio_flags,
863 				 u64 dio_file_offset,
864 				 extent_submit_bio_start_t *submit_bio_start)
865 {
866 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
867 	struct async_submit_bio *async;
868 
869 	async = kmalloc(sizeof(*async), GFP_NOFS);
870 	if (!async)
871 		return BLK_STS_RESOURCE;
872 
873 	async->inode = inode;
874 	async->bio = bio;
875 	async->mirror_num = mirror_num;
876 	async->submit_bio_start = submit_bio_start;
877 
878 	btrfs_init_work(&async->work, run_one_async_start, run_one_async_done,
879 			run_one_async_free);
880 
881 	async->dio_file_offset = dio_file_offset;
882 
883 	async->status = 0;
884 
885 	if (op_is_sync(bio->bi_opf))
886 		btrfs_set_work_high_priority(&async->work);
887 
888 	btrfs_queue_work(fs_info->workers, &async->work);
889 	return 0;
890 }
891 
892 static blk_status_t btree_csum_one_bio(struct bio *bio)
893 {
894 	struct bio_vec *bvec;
895 	struct btrfs_root *root;
896 	int ret = 0;
897 	struct bvec_iter_all iter_all;
898 
899 	ASSERT(!bio_flagged(bio, BIO_CLONED));
900 	bio_for_each_segment_all(bvec, bio, iter_all) {
901 		root = BTRFS_I(bvec->bv_page->mapping->host)->root;
902 		ret = csum_dirty_buffer(root->fs_info, bvec);
903 		if (ret)
904 			break;
905 	}
906 
907 	return errno_to_blk_status(ret);
908 }
909 
910 static blk_status_t btree_submit_bio_start(struct inode *inode, struct bio *bio,
911 					   u64 dio_file_offset)
912 {
913 	/*
914 	 * when we're called for a write, we're already in the async
915 	 * submission context.  Just jump into btrfs_map_bio
916 	 */
917 	return btree_csum_one_bio(bio);
918 }
919 
920 static int check_async_write(struct btrfs_fs_info *fs_info,
921 			     struct btrfs_inode *bi)
922 {
923 	if (btrfs_is_zoned(fs_info))
924 		return 0;
925 	if (atomic_read(&bi->sync_writers))
926 		return 0;
927 	if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
928 		return 0;
929 	return 1;
930 }
931 
932 blk_status_t btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio,
933 				       int mirror_num, unsigned long bio_flags)
934 {
935 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
936 	int async = check_async_write(fs_info, BTRFS_I(inode));
937 	blk_status_t ret;
938 
939 	if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
940 		/*
941 		 * called for a read, do the setup so that checksum validation
942 		 * can happen in the async kernel threads
943 		 */
944 		ret = btrfs_bio_wq_end_io(fs_info, bio,
945 					  BTRFS_WQ_ENDIO_METADATA);
946 		if (ret)
947 			goto out_w_error;
948 		ret = btrfs_map_bio(fs_info, bio, mirror_num);
949 	} else if (!async) {
950 		ret = btree_csum_one_bio(bio);
951 		if (ret)
952 			goto out_w_error;
953 		ret = btrfs_map_bio(fs_info, bio, mirror_num);
954 	} else {
955 		/*
956 		 * kthread helpers are used to submit writes so that
957 		 * checksumming can happen in parallel across all CPUs
958 		 */
959 		ret = btrfs_wq_submit_bio(inode, bio, mirror_num, 0,
960 					  0, btree_submit_bio_start);
961 	}
962 
963 	if (ret)
964 		goto out_w_error;
965 	return 0;
966 
967 out_w_error:
968 	bio->bi_status = ret;
969 	bio_endio(bio);
970 	return ret;
971 }
972 
973 #ifdef CONFIG_MIGRATION
974 static int btree_migratepage(struct address_space *mapping,
975 			struct page *newpage, struct page *page,
976 			enum migrate_mode mode)
977 {
978 	/*
979 	 * we can't safely write a btree page from here,
980 	 * we haven't done the locking hook
981 	 */
982 	if (PageDirty(page))
983 		return -EAGAIN;
984 	/*
985 	 * Buffers may be managed in a filesystem specific way.
986 	 * We must have no buffers or drop them.
987 	 */
988 	if (page_has_private(page) &&
989 	    !try_to_release_page(page, GFP_KERNEL))
990 		return -EAGAIN;
991 	return migrate_page(mapping, newpage, page, mode);
992 }
993 #endif
994 
995 
996 static int btree_writepages(struct address_space *mapping,
997 			    struct writeback_control *wbc)
998 {
999 	struct btrfs_fs_info *fs_info;
1000 	int ret;
1001 
1002 	if (wbc->sync_mode == WB_SYNC_NONE) {
1003 
1004 		if (wbc->for_kupdate)
1005 			return 0;
1006 
1007 		fs_info = BTRFS_I(mapping->host)->root->fs_info;
1008 		/* this is a bit racy, but that's ok */
1009 		ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1010 					     BTRFS_DIRTY_METADATA_THRESH,
1011 					     fs_info->dirty_metadata_batch);
1012 		if (ret < 0)
1013 			return 0;
1014 	}
1015 	return btree_write_cache_pages(mapping, wbc);
1016 }
1017 
1018 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1019 {
1020 	if (PageWriteback(page) || PageDirty(page))
1021 		return 0;
1022 
1023 	return try_release_extent_buffer(page);
1024 }
1025 
1026 static void btree_invalidatepage(struct page *page, unsigned int offset,
1027 				 unsigned int length)
1028 {
1029 	struct extent_io_tree *tree;
1030 	tree = &BTRFS_I(page->mapping->host)->io_tree;
1031 	extent_invalidatepage(tree, page, offset);
1032 	btree_releasepage(page, GFP_NOFS);
1033 	if (PagePrivate(page)) {
1034 		btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1035 			   "page private not zero on page %llu",
1036 			   (unsigned long long)page_offset(page));
1037 		detach_page_private(page);
1038 	}
1039 }
1040 
1041 static int btree_set_page_dirty(struct page *page)
1042 {
1043 #ifdef DEBUG
1044 	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
1045 	struct btrfs_subpage *subpage;
1046 	struct extent_buffer *eb;
1047 	int cur_bit = 0;
1048 	u64 page_start = page_offset(page);
1049 
1050 	if (fs_info->sectorsize == PAGE_SIZE) {
1051 		BUG_ON(!PagePrivate(page));
1052 		eb = (struct extent_buffer *)page->private;
1053 		BUG_ON(!eb);
1054 		BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1055 		BUG_ON(!atomic_read(&eb->refs));
1056 		btrfs_assert_tree_locked(eb);
1057 		return __set_page_dirty_nobuffers(page);
1058 	}
1059 	ASSERT(PagePrivate(page) && page->private);
1060 	subpage = (struct btrfs_subpage *)page->private;
1061 
1062 	ASSERT(subpage->dirty_bitmap);
1063 	while (cur_bit < BTRFS_SUBPAGE_BITMAP_SIZE) {
1064 		unsigned long flags;
1065 		u64 cur;
1066 		u16 tmp = (1 << cur_bit);
1067 
1068 		spin_lock_irqsave(&subpage->lock, flags);
1069 		if (!(tmp & subpage->dirty_bitmap)) {
1070 			spin_unlock_irqrestore(&subpage->lock, flags);
1071 			cur_bit++;
1072 			continue;
1073 		}
1074 		spin_unlock_irqrestore(&subpage->lock, flags);
1075 		cur = page_start + cur_bit * fs_info->sectorsize;
1076 
1077 		eb = find_extent_buffer(fs_info, cur);
1078 		ASSERT(eb);
1079 		ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1080 		ASSERT(atomic_read(&eb->refs));
1081 		btrfs_assert_tree_locked(eb);
1082 		free_extent_buffer(eb);
1083 
1084 		cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits);
1085 	}
1086 #endif
1087 	return __set_page_dirty_nobuffers(page);
1088 }
1089 
1090 static const struct address_space_operations btree_aops = {
1091 	.writepages	= btree_writepages,
1092 	.releasepage	= btree_releasepage,
1093 	.invalidatepage = btree_invalidatepage,
1094 #ifdef CONFIG_MIGRATION
1095 	.migratepage	= btree_migratepage,
1096 #endif
1097 	.set_page_dirty = btree_set_page_dirty,
1098 };
1099 
1100 struct extent_buffer *btrfs_find_create_tree_block(
1101 						struct btrfs_fs_info *fs_info,
1102 						u64 bytenr, u64 owner_root,
1103 						int level)
1104 {
1105 	if (btrfs_is_testing(fs_info))
1106 		return alloc_test_extent_buffer(fs_info, bytenr);
1107 	return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
1108 }
1109 
1110 /*
1111  * Read tree block at logical address @bytenr and do variant basic but critical
1112  * verification.
1113  *
1114  * @owner_root:		the objectid of the root owner for this block.
1115  * @parent_transid:	expected transid of this tree block, skip check if 0
1116  * @level:		expected level, mandatory check
1117  * @first_key:		expected key in slot 0, skip check if NULL
1118  */
1119 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1120 				      u64 owner_root, u64 parent_transid,
1121 				      int level, struct btrfs_key *first_key)
1122 {
1123 	struct extent_buffer *buf = NULL;
1124 	int ret;
1125 
1126 	buf = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level);
1127 	if (IS_ERR(buf))
1128 		return buf;
1129 
1130 	ret = btree_read_extent_buffer_pages(buf, parent_transid,
1131 					     level, first_key);
1132 	if (ret) {
1133 		free_extent_buffer_stale(buf);
1134 		return ERR_PTR(ret);
1135 	}
1136 	return buf;
1137 
1138 }
1139 
1140 void btrfs_clean_tree_block(struct extent_buffer *buf)
1141 {
1142 	struct btrfs_fs_info *fs_info = buf->fs_info;
1143 	if (btrfs_header_generation(buf) ==
1144 	    fs_info->running_transaction->transid) {
1145 		btrfs_assert_tree_locked(buf);
1146 
1147 		if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1148 			percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1149 						 -buf->len,
1150 						 fs_info->dirty_metadata_batch);
1151 			clear_extent_buffer_dirty(buf);
1152 		}
1153 	}
1154 }
1155 
1156 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1157 			 u64 objectid)
1158 {
1159 	bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1160 	root->fs_info = fs_info;
1161 	root->node = NULL;
1162 	root->commit_root = NULL;
1163 	root->state = 0;
1164 	root->orphan_cleanup_state = 0;
1165 
1166 	root->last_trans = 0;
1167 	root->free_objectid = 0;
1168 	root->nr_delalloc_inodes = 0;
1169 	root->nr_ordered_extents = 0;
1170 	root->inode_tree = RB_ROOT;
1171 	INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1172 	root->block_rsv = NULL;
1173 
1174 	INIT_LIST_HEAD(&root->dirty_list);
1175 	INIT_LIST_HEAD(&root->root_list);
1176 	INIT_LIST_HEAD(&root->delalloc_inodes);
1177 	INIT_LIST_HEAD(&root->delalloc_root);
1178 	INIT_LIST_HEAD(&root->ordered_extents);
1179 	INIT_LIST_HEAD(&root->ordered_root);
1180 	INIT_LIST_HEAD(&root->reloc_dirty_list);
1181 	INIT_LIST_HEAD(&root->logged_list[0]);
1182 	INIT_LIST_HEAD(&root->logged_list[1]);
1183 	spin_lock_init(&root->inode_lock);
1184 	spin_lock_init(&root->delalloc_lock);
1185 	spin_lock_init(&root->ordered_extent_lock);
1186 	spin_lock_init(&root->accounting_lock);
1187 	spin_lock_init(&root->log_extents_lock[0]);
1188 	spin_lock_init(&root->log_extents_lock[1]);
1189 	spin_lock_init(&root->qgroup_meta_rsv_lock);
1190 	mutex_init(&root->objectid_mutex);
1191 	mutex_init(&root->log_mutex);
1192 	mutex_init(&root->ordered_extent_mutex);
1193 	mutex_init(&root->delalloc_mutex);
1194 	init_waitqueue_head(&root->qgroup_flush_wait);
1195 	init_waitqueue_head(&root->log_writer_wait);
1196 	init_waitqueue_head(&root->log_commit_wait[0]);
1197 	init_waitqueue_head(&root->log_commit_wait[1]);
1198 	INIT_LIST_HEAD(&root->log_ctxs[0]);
1199 	INIT_LIST_HEAD(&root->log_ctxs[1]);
1200 	atomic_set(&root->log_commit[0], 0);
1201 	atomic_set(&root->log_commit[1], 0);
1202 	atomic_set(&root->log_writers, 0);
1203 	atomic_set(&root->log_batch, 0);
1204 	refcount_set(&root->refs, 1);
1205 	atomic_set(&root->snapshot_force_cow, 0);
1206 	atomic_set(&root->nr_swapfiles, 0);
1207 	root->log_transid = 0;
1208 	root->log_transid_committed = -1;
1209 	root->last_log_commit = 0;
1210 	if (!dummy) {
1211 		extent_io_tree_init(fs_info, &root->dirty_log_pages,
1212 				    IO_TREE_ROOT_DIRTY_LOG_PAGES, NULL);
1213 		extent_io_tree_init(fs_info, &root->log_csum_range,
1214 				    IO_TREE_LOG_CSUM_RANGE, NULL);
1215 	}
1216 
1217 	memset(&root->root_key, 0, sizeof(root->root_key));
1218 	memset(&root->root_item, 0, sizeof(root->root_item));
1219 	memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1220 	root->root_key.objectid = objectid;
1221 	root->anon_dev = 0;
1222 
1223 	spin_lock_init(&root->root_item_lock);
1224 	btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
1225 #ifdef CONFIG_BTRFS_DEBUG
1226 	INIT_LIST_HEAD(&root->leak_list);
1227 	spin_lock(&fs_info->fs_roots_radix_lock);
1228 	list_add_tail(&root->leak_list, &fs_info->allocated_roots);
1229 	spin_unlock(&fs_info->fs_roots_radix_lock);
1230 #endif
1231 }
1232 
1233 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1234 					   u64 objectid, gfp_t flags)
1235 {
1236 	struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1237 	if (root)
1238 		__setup_root(root, fs_info, objectid);
1239 	return root;
1240 }
1241 
1242 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1243 /* Should only be used by the testing infrastructure */
1244 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1245 {
1246 	struct btrfs_root *root;
1247 
1248 	if (!fs_info)
1249 		return ERR_PTR(-EINVAL);
1250 
1251 	root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
1252 	if (!root)
1253 		return ERR_PTR(-ENOMEM);
1254 
1255 	/* We don't use the stripesize in selftest, set it as sectorsize */
1256 	root->alloc_bytenr = 0;
1257 
1258 	return root;
1259 }
1260 #endif
1261 
1262 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1263 				     u64 objectid)
1264 {
1265 	struct btrfs_fs_info *fs_info = trans->fs_info;
1266 	struct extent_buffer *leaf;
1267 	struct btrfs_root *tree_root = fs_info->tree_root;
1268 	struct btrfs_root *root;
1269 	struct btrfs_key key;
1270 	unsigned int nofs_flag;
1271 	int ret = 0;
1272 
1273 	/*
1274 	 * We're holding a transaction handle, so use a NOFS memory allocation
1275 	 * context to avoid deadlock if reclaim happens.
1276 	 */
1277 	nofs_flag = memalloc_nofs_save();
1278 	root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
1279 	memalloc_nofs_restore(nofs_flag);
1280 	if (!root)
1281 		return ERR_PTR(-ENOMEM);
1282 
1283 	root->root_key.objectid = objectid;
1284 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1285 	root->root_key.offset = 0;
1286 
1287 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
1288 				      BTRFS_NESTING_NORMAL);
1289 	if (IS_ERR(leaf)) {
1290 		ret = PTR_ERR(leaf);
1291 		leaf = NULL;
1292 		goto fail_unlock;
1293 	}
1294 
1295 	root->node = leaf;
1296 	btrfs_mark_buffer_dirty(leaf);
1297 
1298 	root->commit_root = btrfs_root_node(root);
1299 	set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1300 
1301 	btrfs_set_root_flags(&root->root_item, 0);
1302 	btrfs_set_root_limit(&root->root_item, 0);
1303 	btrfs_set_root_bytenr(&root->root_item, leaf->start);
1304 	btrfs_set_root_generation(&root->root_item, trans->transid);
1305 	btrfs_set_root_level(&root->root_item, 0);
1306 	btrfs_set_root_refs(&root->root_item, 1);
1307 	btrfs_set_root_used(&root->root_item, leaf->len);
1308 	btrfs_set_root_last_snapshot(&root->root_item, 0);
1309 	btrfs_set_root_dirid(&root->root_item, 0);
1310 	if (is_fstree(objectid))
1311 		generate_random_guid(root->root_item.uuid);
1312 	else
1313 		export_guid(root->root_item.uuid, &guid_null);
1314 	btrfs_set_root_drop_level(&root->root_item, 0);
1315 
1316 	btrfs_tree_unlock(leaf);
1317 
1318 	key.objectid = objectid;
1319 	key.type = BTRFS_ROOT_ITEM_KEY;
1320 	key.offset = 0;
1321 	ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1322 	if (ret)
1323 		goto fail;
1324 
1325 	return root;
1326 
1327 fail_unlock:
1328 	if (leaf)
1329 		btrfs_tree_unlock(leaf);
1330 fail:
1331 	btrfs_put_root(root);
1332 
1333 	return ERR_PTR(ret);
1334 }
1335 
1336 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1337 					 struct btrfs_fs_info *fs_info)
1338 {
1339 	struct btrfs_root *root;
1340 
1341 	root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
1342 	if (!root)
1343 		return ERR_PTR(-ENOMEM);
1344 
1345 	root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1346 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1347 	root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1348 
1349 	return root;
1350 }
1351 
1352 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
1353 			      struct btrfs_root *root)
1354 {
1355 	struct extent_buffer *leaf;
1356 
1357 	/*
1358 	 * DON'T set SHAREABLE bit for log trees.
1359 	 *
1360 	 * Log trees are not exposed to user space thus can't be snapshotted,
1361 	 * and they go away before a real commit is actually done.
1362 	 *
1363 	 * They do store pointers to file data extents, and those reference
1364 	 * counts still get updated (along with back refs to the log tree).
1365 	 */
1366 
1367 	leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1368 			NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
1369 	if (IS_ERR(leaf))
1370 		return PTR_ERR(leaf);
1371 
1372 	root->node = leaf;
1373 
1374 	btrfs_mark_buffer_dirty(root->node);
1375 	btrfs_tree_unlock(root->node);
1376 
1377 	return 0;
1378 }
1379 
1380 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1381 			     struct btrfs_fs_info *fs_info)
1382 {
1383 	struct btrfs_root *log_root;
1384 
1385 	log_root = alloc_log_tree(trans, fs_info);
1386 	if (IS_ERR(log_root))
1387 		return PTR_ERR(log_root);
1388 
1389 	if (!btrfs_is_zoned(fs_info)) {
1390 		int ret = btrfs_alloc_log_tree_node(trans, log_root);
1391 
1392 		if (ret) {
1393 			btrfs_put_root(log_root);
1394 			return ret;
1395 		}
1396 	}
1397 
1398 	WARN_ON(fs_info->log_root_tree);
1399 	fs_info->log_root_tree = log_root;
1400 	return 0;
1401 }
1402 
1403 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1404 		       struct btrfs_root *root)
1405 {
1406 	struct btrfs_fs_info *fs_info = root->fs_info;
1407 	struct btrfs_root *log_root;
1408 	struct btrfs_inode_item *inode_item;
1409 	int ret;
1410 
1411 	log_root = alloc_log_tree(trans, fs_info);
1412 	if (IS_ERR(log_root))
1413 		return PTR_ERR(log_root);
1414 
1415 	ret = btrfs_alloc_log_tree_node(trans, log_root);
1416 	if (ret) {
1417 		btrfs_put_root(log_root);
1418 		return ret;
1419 	}
1420 
1421 	log_root->last_trans = trans->transid;
1422 	log_root->root_key.offset = root->root_key.objectid;
1423 
1424 	inode_item = &log_root->root_item.inode;
1425 	btrfs_set_stack_inode_generation(inode_item, 1);
1426 	btrfs_set_stack_inode_size(inode_item, 3);
1427 	btrfs_set_stack_inode_nlink(inode_item, 1);
1428 	btrfs_set_stack_inode_nbytes(inode_item,
1429 				     fs_info->nodesize);
1430 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1431 
1432 	btrfs_set_root_node(&log_root->root_item, log_root->node);
1433 
1434 	WARN_ON(root->log_root);
1435 	root->log_root = log_root;
1436 	root->log_transid = 0;
1437 	root->log_transid_committed = -1;
1438 	root->last_log_commit = 0;
1439 	return 0;
1440 }
1441 
1442 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1443 					      struct btrfs_path *path,
1444 					      struct btrfs_key *key)
1445 {
1446 	struct btrfs_root *root;
1447 	struct btrfs_fs_info *fs_info = tree_root->fs_info;
1448 	u64 generation;
1449 	int ret;
1450 	int level;
1451 
1452 	root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1453 	if (!root)
1454 		return ERR_PTR(-ENOMEM);
1455 
1456 	ret = btrfs_find_root(tree_root, key, path,
1457 			      &root->root_item, &root->root_key);
1458 	if (ret) {
1459 		if (ret > 0)
1460 			ret = -ENOENT;
1461 		goto fail;
1462 	}
1463 
1464 	generation = btrfs_root_generation(&root->root_item);
1465 	level = btrfs_root_level(&root->root_item);
1466 	root->node = read_tree_block(fs_info,
1467 				     btrfs_root_bytenr(&root->root_item),
1468 				     key->objectid, generation, level, NULL);
1469 	if (IS_ERR(root->node)) {
1470 		ret = PTR_ERR(root->node);
1471 		root->node = NULL;
1472 		goto fail;
1473 	} else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1474 		ret = -EIO;
1475 		goto fail;
1476 	}
1477 	root->commit_root = btrfs_root_node(root);
1478 	return root;
1479 fail:
1480 	btrfs_put_root(root);
1481 	return ERR_PTR(ret);
1482 }
1483 
1484 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1485 					struct btrfs_key *key)
1486 {
1487 	struct btrfs_root *root;
1488 	struct btrfs_path *path;
1489 
1490 	path = btrfs_alloc_path();
1491 	if (!path)
1492 		return ERR_PTR(-ENOMEM);
1493 	root = read_tree_root_path(tree_root, path, key);
1494 	btrfs_free_path(path);
1495 
1496 	return root;
1497 }
1498 
1499 /*
1500  * Initialize subvolume root in-memory structure
1501  *
1502  * @anon_dev:	anonymous device to attach to the root, if zero, allocate new
1503  */
1504 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1505 {
1506 	int ret;
1507 	unsigned int nofs_flag;
1508 
1509 	/*
1510 	 * We might be called under a transaction (e.g. indirect backref
1511 	 * resolution) which could deadlock if it triggers memory reclaim
1512 	 */
1513 	nofs_flag = memalloc_nofs_save();
1514 	ret = btrfs_drew_lock_init(&root->snapshot_lock);
1515 	memalloc_nofs_restore(nofs_flag);
1516 	if (ret)
1517 		goto fail;
1518 
1519 	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1520 	    root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
1521 		set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1522 		btrfs_check_and_init_root_item(&root->root_item);
1523 	}
1524 
1525 	/*
1526 	 * Don't assign anonymous block device to roots that are not exposed to
1527 	 * userspace, the id pool is limited to 1M
1528 	 */
1529 	if (is_fstree(root->root_key.objectid) &&
1530 	    btrfs_root_refs(&root->root_item) > 0) {
1531 		if (!anon_dev) {
1532 			ret = get_anon_bdev(&root->anon_dev);
1533 			if (ret)
1534 				goto fail;
1535 		} else {
1536 			root->anon_dev = anon_dev;
1537 		}
1538 	}
1539 
1540 	mutex_lock(&root->objectid_mutex);
1541 	ret = btrfs_init_root_free_objectid(root);
1542 	if (ret) {
1543 		mutex_unlock(&root->objectid_mutex);
1544 		goto fail;
1545 	}
1546 
1547 	ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1548 
1549 	mutex_unlock(&root->objectid_mutex);
1550 
1551 	return 0;
1552 fail:
1553 	/* The caller is responsible to call btrfs_free_fs_root */
1554 	return ret;
1555 }
1556 
1557 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1558 					       u64 root_id)
1559 {
1560 	struct btrfs_root *root;
1561 
1562 	spin_lock(&fs_info->fs_roots_radix_lock);
1563 	root = radix_tree_lookup(&fs_info->fs_roots_radix,
1564 				 (unsigned long)root_id);
1565 	if (root)
1566 		root = btrfs_grab_root(root);
1567 	spin_unlock(&fs_info->fs_roots_radix_lock);
1568 	return root;
1569 }
1570 
1571 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1572 						u64 objectid)
1573 {
1574 	if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1575 		return btrfs_grab_root(fs_info->tree_root);
1576 	if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1577 		return btrfs_grab_root(fs_info->extent_root);
1578 	if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1579 		return btrfs_grab_root(fs_info->chunk_root);
1580 	if (objectid == BTRFS_DEV_TREE_OBJECTID)
1581 		return btrfs_grab_root(fs_info->dev_root);
1582 	if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1583 		return btrfs_grab_root(fs_info->csum_root);
1584 	if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1585 		return btrfs_grab_root(fs_info->quota_root) ?
1586 			fs_info->quota_root : ERR_PTR(-ENOENT);
1587 	if (objectid == BTRFS_UUID_TREE_OBJECTID)
1588 		return btrfs_grab_root(fs_info->uuid_root) ?
1589 			fs_info->uuid_root : ERR_PTR(-ENOENT);
1590 	if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1591 		return btrfs_grab_root(fs_info->free_space_root) ?
1592 			fs_info->free_space_root : ERR_PTR(-ENOENT);
1593 	return NULL;
1594 }
1595 
1596 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1597 			 struct btrfs_root *root)
1598 {
1599 	int ret;
1600 
1601 	ret = radix_tree_preload(GFP_NOFS);
1602 	if (ret)
1603 		return ret;
1604 
1605 	spin_lock(&fs_info->fs_roots_radix_lock);
1606 	ret = radix_tree_insert(&fs_info->fs_roots_radix,
1607 				(unsigned long)root->root_key.objectid,
1608 				root);
1609 	if (ret == 0) {
1610 		btrfs_grab_root(root);
1611 		set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1612 	}
1613 	spin_unlock(&fs_info->fs_roots_radix_lock);
1614 	radix_tree_preload_end();
1615 
1616 	return ret;
1617 }
1618 
1619 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
1620 {
1621 #ifdef CONFIG_BTRFS_DEBUG
1622 	struct btrfs_root *root;
1623 
1624 	while (!list_empty(&fs_info->allocated_roots)) {
1625 		char buf[BTRFS_ROOT_NAME_BUF_LEN];
1626 
1627 		root = list_first_entry(&fs_info->allocated_roots,
1628 					struct btrfs_root, leak_list);
1629 		btrfs_err(fs_info, "leaked root %s refcount %d",
1630 			  btrfs_root_name(&root->root_key, buf),
1631 			  refcount_read(&root->refs));
1632 		while (refcount_read(&root->refs) > 1)
1633 			btrfs_put_root(root);
1634 		btrfs_put_root(root);
1635 	}
1636 #endif
1637 }
1638 
1639 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1640 {
1641 	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1642 	percpu_counter_destroy(&fs_info->delalloc_bytes);
1643 	percpu_counter_destroy(&fs_info->ordered_bytes);
1644 	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1645 	btrfs_free_csum_hash(fs_info);
1646 	btrfs_free_stripe_hash_table(fs_info);
1647 	btrfs_free_ref_cache(fs_info);
1648 	kfree(fs_info->balance_ctl);
1649 	kfree(fs_info->delayed_root);
1650 	btrfs_put_root(fs_info->extent_root);
1651 	btrfs_put_root(fs_info->tree_root);
1652 	btrfs_put_root(fs_info->chunk_root);
1653 	btrfs_put_root(fs_info->dev_root);
1654 	btrfs_put_root(fs_info->csum_root);
1655 	btrfs_put_root(fs_info->quota_root);
1656 	btrfs_put_root(fs_info->uuid_root);
1657 	btrfs_put_root(fs_info->free_space_root);
1658 	btrfs_put_root(fs_info->fs_root);
1659 	btrfs_put_root(fs_info->data_reloc_root);
1660 	btrfs_check_leaked_roots(fs_info);
1661 	btrfs_extent_buffer_leak_debug_check(fs_info);
1662 	kfree(fs_info->super_copy);
1663 	kfree(fs_info->super_for_commit);
1664 	kvfree(fs_info);
1665 }
1666 
1667 
1668 /*
1669  * Get an in-memory reference of a root structure.
1670  *
1671  * For essential trees like root/extent tree, we grab it from fs_info directly.
1672  * For subvolume trees, we check the cached filesystem roots first. If not
1673  * found, then read it from disk and add it to cached fs roots.
1674  *
1675  * Caller should release the root by calling btrfs_put_root() after the usage.
1676  *
1677  * NOTE: Reloc and log trees can't be read by this function as they share the
1678  *	 same root objectid.
1679  *
1680  * @objectid:	root id
1681  * @anon_dev:	preallocated anonymous block device number for new roots,
1682  * 		pass 0 for new allocation.
1683  * @check_ref:	whether to check root item references, If true, return -ENOENT
1684  *		for orphan roots
1685  */
1686 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1687 					     u64 objectid, dev_t anon_dev,
1688 					     bool check_ref)
1689 {
1690 	struct btrfs_root *root;
1691 	struct btrfs_path *path;
1692 	struct btrfs_key key;
1693 	int ret;
1694 
1695 	root = btrfs_get_global_root(fs_info, objectid);
1696 	if (root)
1697 		return root;
1698 again:
1699 	root = btrfs_lookup_fs_root(fs_info, objectid);
1700 	if (root) {
1701 		/* Shouldn't get preallocated anon_dev for cached roots */
1702 		ASSERT(!anon_dev);
1703 		if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1704 			btrfs_put_root(root);
1705 			return ERR_PTR(-ENOENT);
1706 		}
1707 		return root;
1708 	}
1709 
1710 	key.objectid = objectid;
1711 	key.type = BTRFS_ROOT_ITEM_KEY;
1712 	key.offset = (u64)-1;
1713 	root = btrfs_read_tree_root(fs_info->tree_root, &key);
1714 	if (IS_ERR(root))
1715 		return root;
1716 
1717 	if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1718 		ret = -ENOENT;
1719 		goto fail;
1720 	}
1721 
1722 	ret = btrfs_init_fs_root(root, anon_dev);
1723 	if (ret)
1724 		goto fail;
1725 
1726 	path = btrfs_alloc_path();
1727 	if (!path) {
1728 		ret = -ENOMEM;
1729 		goto fail;
1730 	}
1731 	key.objectid = BTRFS_ORPHAN_OBJECTID;
1732 	key.type = BTRFS_ORPHAN_ITEM_KEY;
1733 	key.offset = objectid;
1734 
1735 	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1736 	btrfs_free_path(path);
1737 	if (ret < 0)
1738 		goto fail;
1739 	if (ret == 0)
1740 		set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1741 
1742 	ret = btrfs_insert_fs_root(fs_info, root);
1743 	if (ret) {
1744 		btrfs_put_root(root);
1745 		if (ret == -EEXIST)
1746 			goto again;
1747 		goto fail;
1748 	}
1749 	return root;
1750 fail:
1751 	btrfs_put_root(root);
1752 	return ERR_PTR(ret);
1753 }
1754 
1755 /*
1756  * Get in-memory reference of a root structure
1757  *
1758  * @objectid:	tree objectid
1759  * @check_ref:	if set, verify that the tree exists and the item has at least
1760  *		one reference
1761  */
1762 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1763 				     u64 objectid, bool check_ref)
1764 {
1765 	return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
1766 }
1767 
1768 /*
1769  * Get in-memory reference of a root structure, created as new, optionally pass
1770  * the anonymous block device id
1771  *
1772  * @objectid:	tree objectid
1773  * @anon_dev:	if zero, allocate a new anonymous block device or use the
1774  *		parameter value
1775  */
1776 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1777 					 u64 objectid, dev_t anon_dev)
1778 {
1779 	return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1780 }
1781 
1782 /*
1783  * btrfs_get_fs_root_commit_root - return a root for the given objectid
1784  * @fs_info:	the fs_info
1785  * @objectid:	the objectid we need to lookup
1786  *
1787  * This is exclusively used for backref walking, and exists specifically because
1788  * of how qgroups does lookups.  Qgroups will do a backref lookup at delayed ref
1789  * creation time, which means we may have to read the tree_root in order to look
1790  * up a fs root that is not in memory.  If the root is not in memory we will
1791  * read the tree root commit root and look up the fs root from there.  This is a
1792  * temporary root, it will not be inserted into the radix tree as it doesn't
1793  * have the most uptodate information, it'll simply be discarded once the
1794  * backref code is finished using the root.
1795  */
1796 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1797 						 struct btrfs_path *path,
1798 						 u64 objectid)
1799 {
1800 	struct btrfs_root *root;
1801 	struct btrfs_key key;
1802 
1803 	ASSERT(path->search_commit_root && path->skip_locking);
1804 
1805 	/*
1806 	 * This can return -ENOENT if we ask for a root that doesn't exist, but
1807 	 * since this is called via the backref walking code we won't be looking
1808 	 * up a root that doesn't exist, unless there's corruption.  So if root
1809 	 * != NULL just return it.
1810 	 */
1811 	root = btrfs_get_global_root(fs_info, objectid);
1812 	if (root)
1813 		return root;
1814 
1815 	root = btrfs_lookup_fs_root(fs_info, objectid);
1816 	if (root)
1817 		return root;
1818 
1819 	key.objectid = objectid;
1820 	key.type = BTRFS_ROOT_ITEM_KEY;
1821 	key.offset = (u64)-1;
1822 	root = read_tree_root_path(fs_info->tree_root, path, &key);
1823 	btrfs_release_path(path);
1824 
1825 	return root;
1826 }
1827 
1828 /*
1829  * called by the kthread helper functions to finally call the bio end_io
1830  * functions.  This is where read checksum verification actually happens
1831  */
1832 static void end_workqueue_fn(struct btrfs_work *work)
1833 {
1834 	struct bio *bio;
1835 	struct btrfs_end_io_wq *end_io_wq;
1836 
1837 	end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1838 	bio = end_io_wq->bio;
1839 
1840 	bio->bi_status = end_io_wq->status;
1841 	bio->bi_private = end_io_wq->private;
1842 	bio->bi_end_io = end_io_wq->end_io;
1843 	bio_endio(bio);
1844 	kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1845 }
1846 
1847 static int cleaner_kthread(void *arg)
1848 {
1849 	struct btrfs_root *root = arg;
1850 	struct btrfs_fs_info *fs_info = root->fs_info;
1851 	int again;
1852 
1853 	while (1) {
1854 		again = 0;
1855 
1856 		set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1857 
1858 		/* Make the cleaner go to sleep early. */
1859 		if (btrfs_need_cleaner_sleep(fs_info))
1860 			goto sleep;
1861 
1862 		/*
1863 		 * Do not do anything if we might cause open_ctree() to block
1864 		 * before we have finished mounting the filesystem.
1865 		 */
1866 		if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1867 			goto sleep;
1868 
1869 		if (!mutex_trylock(&fs_info->cleaner_mutex))
1870 			goto sleep;
1871 
1872 		/*
1873 		 * Avoid the problem that we change the status of the fs
1874 		 * during the above check and trylock.
1875 		 */
1876 		if (btrfs_need_cleaner_sleep(fs_info)) {
1877 			mutex_unlock(&fs_info->cleaner_mutex);
1878 			goto sleep;
1879 		}
1880 
1881 		btrfs_run_delayed_iputs(fs_info);
1882 
1883 		again = btrfs_clean_one_deleted_snapshot(root);
1884 		mutex_unlock(&fs_info->cleaner_mutex);
1885 
1886 		/*
1887 		 * The defragger has dealt with the R/O remount and umount,
1888 		 * needn't do anything special here.
1889 		 */
1890 		btrfs_run_defrag_inodes(fs_info);
1891 
1892 		/*
1893 		 * Acquires fs_info->reclaim_bgs_lock to avoid racing
1894 		 * with relocation (btrfs_relocate_chunk) and relocation
1895 		 * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1896 		 * after acquiring fs_info->reclaim_bgs_lock. So we
1897 		 * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1898 		 * unused block groups.
1899 		 */
1900 		btrfs_delete_unused_bgs(fs_info);
1901 
1902 		/*
1903 		 * Reclaim block groups in the reclaim_bgs list after we deleted
1904 		 * all unused block_groups. This possibly gives us some more free
1905 		 * space.
1906 		 */
1907 		btrfs_reclaim_bgs(fs_info);
1908 sleep:
1909 		clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1910 		if (kthread_should_park())
1911 			kthread_parkme();
1912 		if (kthread_should_stop())
1913 			return 0;
1914 		if (!again) {
1915 			set_current_state(TASK_INTERRUPTIBLE);
1916 			schedule();
1917 			__set_current_state(TASK_RUNNING);
1918 		}
1919 	}
1920 }
1921 
1922 static int transaction_kthread(void *arg)
1923 {
1924 	struct btrfs_root *root = arg;
1925 	struct btrfs_fs_info *fs_info = root->fs_info;
1926 	struct btrfs_trans_handle *trans;
1927 	struct btrfs_transaction *cur;
1928 	u64 transid;
1929 	time64_t delta;
1930 	unsigned long delay;
1931 	bool cannot_commit;
1932 
1933 	do {
1934 		cannot_commit = false;
1935 		delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1936 		mutex_lock(&fs_info->transaction_kthread_mutex);
1937 
1938 		spin_lock(&fs_info->trans_lock);
1939 		cur = fs_info->running_transaction;
1940 		if (!cur) {
1941 			spin_unlock(&fs_info->trans_lock);
1942 			goto sleep;
1943 		}
1944 
1945 		delta = ktime_get_seconds() - cur->start_time;
1946 		if (cur->state < TRANS_STATE_COMMIT_START &&
1947 		    delta < fs_info->commit_interval) {
1948 			spin_unlock(&fs_info->trans_lock);
1949 			delay -= msecs_to_jiffies((delta - 1) * 1000);
1950 			delay = min(delay,
1951 				    msecs_to_jiffies(fs_info->commit_interval * 1000));
1952 			goto sleep;
1953 		}
1954 		transid = cur->transid;
1955 		spin_unlock(&fs_info->trans_lock);
1956 
1957 		/* If the file system is aborted, this will always fail. */
1958 		trans = btrfs_attach_transaction(root);
1959 		if (IS_ERR(trans)) {
1960 			if (PTR_ERR(trans) != -ENOENT)
1961 				cannot_commit = true;
1962 			goto sleep;
1963 		}
1964 		if (transid == trans->transid) {
1965 			btrfs_commit_transaction(trans);
1966 		} else {
1967 			btrfs_end_transaction(trans);
1968 		}
1969 sleep:
1970 		wake_up_process(fs_info->cleaner_kthread);
1971 		mutex_unlock(&fs_info->transaction_kthread_mutex);
1972 
1973 		if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1974 				      &fs_info->fs_state)))
1975 			btrfs_cleanup_transaction(fs_info);
1976 		if (!kthread_should_stop() &&
1977 				(!btrfs_transaction_blocked(fs_info) ||
1978 				 cannot_commit))
1979 			schedule_timeout_interruptible(delay);
1980 	} while (!kthread_should_stop());
1981 	return 0;
1982 }
1983 
1984 /*
1985  * This will find the highest generation in the array of root backups.  The
1986  * index of the highest array is returned, or -EINVAL if we can't find
1987  * anything.
1988  *
1989  * We check to make sure the array is valid by comparing the
1990  * generation of the latest  root in the array with the generation
1991  * in the super block.  If they don't match we pitch it.
1992  */
1993 static int find_newest_super_backup(struct btrfs_fs_info *info)
1994 {
1995 	const u64 newest_gen = btrfs_super_generation(info->super_copy);
1996 	u64 cur;
1997 	struct btrfs_root_backup *root_backup;
1998 	int i;
1999 
2000 	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2001 		root_backup = info->super_copy->super_roots + i;
2002 		cur = btrfs_backup_tree_root_gen(root_backup);
2003 		if (cur == newest_gen)
2004 			return i;
2005 	}
2006 
2007 	return -EINVAL;
2008 }
2009 
2010 /*
2011  * copy all the root pointers into the super backup array.
2012  * this will bump the backup pointer by one when it is
2013  * done
2014  */
2015 static void backup_super_roots(struct btrfs_fs_info *info)
2016 {
2017 	const int next_backup = info->backup_root_index;
2018 	struct btrfs_root_backup *root_backup;
2019 
2020 	root_backup = info->super_for_commit->super_roots + next_backup;
2021 
2022 	/*
2023 	 * make sure all of our padding and empty slots get zero filled
2024 	 * regardless of which ones we use today
2025 	 */
2026 	memset(root_backup, 0, sizeof(*root_backup));
2027 
2028 	info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2029 
2030 	btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2031 	btrfs_set_backup_tree_root_gen(root_backup,
2032 			       btrfs_header_generation(info->tree_root->node));
2033 
2034 	btrfs_set_backup_tree_root_level(root_backup,
2035 			       btrfs_header_level(info->tree_root->node));
2036 
2037 	btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2038 	btrfs_set_backup_chunk_root_gen(root_backup,
2039 			       btrfs_header_generation(info->chunk_root->node));
2040 	btrfs_set_backup_chunk_root_level(root_backup,
2041 			       btrfs_header_level(info->chunk_root->node));
2042 
2043 	btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
2044 	btrfs_set_backup_extent_root_gen(root_backup,
2045 			       btrfs_header_generation(info->extent_root->node));
2046 	btrfs_set_backup_extent_root_level(root_backup,
2047 			       btrfs_header_level(info->extent_root->node));
2048 
2049 	/*
2050 	 * we might commit during log recovery, which happens before we set
2051 	 * the fs_root.  Make sure it is valid before we fill it in.
2052 	 */
2053 	if (info->fs_root && info->fs_root->node) {
2054 		btrfs_set_backup_fs_root(root_backup,
2055 					 info->fs_root->node->start);
2056 		btrfs_set_backup_fs_root_gen(root_backup,
2057 			       btrfs_header_generation(info->fs_root->node));
2058 		btrfs_set_backup_fs_root_level(root_backup,
2059 			       btrfs_header_level(info->fs_root->node));
2060 	}
2061 
2062 	btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2063 	btrfs_set_backup_dev_root_gen(root_backup,
2064 			       btrfs_header_generation(info->dev_root->node));
2065 	btrfs_set_backup_dev_root_level(root_backup,
2066 				       btrfs_header_level(info->dev_root->node));
2067 
2068 	btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
2069 	btrfs_set_backup_csum_root_gen(root_backup,
2070 			       btrfs_header_generation(info->csum_root->node));
2071 	btrfs_set_backup_csum_root_level(root_backup,
2072 			       btrfs_header_level(info->csum_root->node));
2073 
2074 	btrfs_set_backup_total_bytes(root_backup,
2075 			     btrfs_super_total_bytes(info->super_copy));
2076 	btrfs_set_backup_bytes_used(root_backup,
2077 			     btrfs_super_bytes_used(info->super_copy));
2078 	btrfs_set_backup_num_devices(root_backup,
2079 			     btrfs_super_num_devices(info->super_copy));
2080 
2081 	/*
2082 	 * if we don't copy this out to the super_copy, it won't get remembered
2083 	 * for the next commit
2084 	 */
2085 	memcpy(&info->super_copy->super_roots,
2086 	       &info->super_for_commit->super_roots,
2087 	       sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2088 }
2089 
2090 /*
2091  * read_backup_root - Reads a backup root based on the passed priority. Prio 0
2092  * is the newest, prio 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
2093  *
2094  * fs_info - filesystem whose backup roots need to be read
2095  * priority - priority of backup root required
2096  *
2097  * Returns backup root index on success and -EINVAL otherwise.
2098  */
2099 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
2100 {
2101 	int backup_index = find_newest_super_backup(fs_info);
2102 	struct btrfs_super_block *super = fs_info->super_copy;
2103 	struct btrfs_root_backup *root_backup;
2104 
2105 	if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
2106 		if (priority == 0)
2107 			return backup_index;
2108 
2109 		backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
2110 		backup_index %= BTRFS_NUM_BACKUP_ROOTS;
2111 	} else {
2112 		return -EINVAL;
2113 	}
2114 
2115 	root_backup = super->super_roots + backup_index;
2116 
2117 	btrfs_set_super_generation(super,
2118 				   btrfs_backup_tree_root_gen(root_backup));
2119 	btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2120 	btrfs_set_super_root_level(super,
2121 				   btrfs_backup_tree_root_level(root_backup));
2122 	btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2123 
2124 	/*
2125 	 * Fixme: the total bytes and num_devices need to match or we should
2126 	 * need a fsck
2127 	 */
2128 	btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2129 	btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2130 
2131 	return backup_index;
2132 }
2133 
2134 /* helper to cleanup workers */
2135 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2136 {
2137 	btrfs_destroy_workqueue(fs_info->fixup_workers);
2138 	btrfs_destroy_workqueue(fs_info->delalloc_workers);
2139 	btrfs_destroy_workqueue(fs_info->workers);
2140 	btrfs_destroy_workqueue(fs_info->endio_workers);
2141 	btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2142 	btrfs_destroy_workqueue(fs_info->rmw_workers);
2143 	btrfs_destroy_workqueue(fs_info->endio_write_workers);
2144 	btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2145 	btrfs_destroy_workqueue(fs_info->delayed_workers);
2146 	btrfs_destroy_workqueue(fs_info->caching_workers);
2147 	btrfs_destroy_workqueue(fs_info->readahead_workers);
2148 	btrfs_destroy_workqueue(fs_info->flush_workers);
2149 	btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2150 	if (fs_info->discard_ctl.discard_workers)
2151 		destroy_workqueue(fs_info->discard_ctl.discard_workers);
2152 	/*
2153 	 * Now that all other work queues are destroyed, we can safely destroy
2154 	 * the queues used for metadata I/O, since tasks from those other work
2155 	 * queues can do metadata I/O operations.
2156 	 */
2157 	btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2158 	btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2159 }
2160 
2161 static void free_root_extent_buffers(struct btrfs_root *root)
2162 {
2163 	if (root) {
2164 		free_extent_buffer(root->node);
2165 		free_extent_buffer(root->commit_root);
2166 		root->node = NULL;
2167 		root->commit_root = NULL;
2168 	}
2169 }
2170 
2171 /* helper to cleanup tree roots */
2172 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
2173 {
2174 	free_root_extent_buffers(info->tree_root);
2175 
2176 	free_root_extent_buffers(info->dev_root);
2177 	free_root_extent_buffers(info->extent_root);
2178 	free_root_extent_buffers(info->csum_root);
2179 	free_root_extent_buffers(info->quota_root);
2180 	free_root_extent_buffers(info->uuid_root);
2181 	free_root_extent_buffers(info->fs_root);
2182 	free_root_extent_buffers(info->data_reloc_root);
2183 	if (free_chunk_root)
2184 		free_root_extent_buffers(info->chunk_root);
2185 	free_root_extent_buffers(info->free_space_root);
2186 }
2187 
2188 void btrfs_put_root(struct btrfs_root *root)
2189 {
2190 	if (!root)
2191 		return;
2192 
2193 	if (refcount_dec_and_test(&root->refs)) {
2194 		WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2195 		WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
2196 		if (root->anon_dev)
2197 			free_anon_bdev(root->anon_dev);
2198 		btrfs_drew_lock_destroy(&root->snapshot_lock);
2199 		free_root_extent_buffers(root);
2200 #ifdef CONFIG_BTRFS_DEBUG
2201 		spin_lock(&root->fs_info->fs_roots_radix_lock);
2202 		list_del_init(&root->leak_list);
2203 		spin_unlock(&root->fs_info->fs_roots_radix_lock);
2204 #endif
2205 		kfree(root);
2206 	}
2207 }
2208 
2209 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2210 {
2211 	int ret;
2212 	struct btrfs_root *gang[8];
2213 	int i;
2214 
2215 	while (!list_empty(&fs_info->dead_roots)) {
2216 		gang[0] = list_entry(fs_info->dead_roots.next,
2217 				     struct btrfs_root, root_list);
2218 		list_del(&gang[0]->root_list);
2219 
2220 		if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
2221 			btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2222 		btrfs_put_root(gang[0]);
2223 	}
2224 
2225 	while (1) {
2226 		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2227 					     (void **)gang, 0,
2228 					     ARRAY_SIZE(gang));
2229 		if (!ret)
2230 			break;
2231 		for (i = 0; i < ret; i++)
2232 			btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2233 	}
2234 }
2235 
2236 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2237 {
2238 	mutex_init(&fs_info->scrub_lock);
2239 	atomic_set(&fs_info->scrubs_running, 0);
2240 	atomic_set(&fs_info->scrub_pause_req, 0);
2241 	atomic_set(&fs_info->scrubs_paused, 0);
2242 	atomic_set(&fs_info->scrub_cancel_req, 0);
2243 	init_waitqueue_head(&fs_info->scrub_pause_wait);
2244 	refcount_set(&fs_info->scrub_workers_refcnt, 0);
2245 }
2246 
2247 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2248 {
2249 	spin_lock_init(&fs_info->balance_lock);
2250 	mutex_init(&fs_info->balance_mutex);
2251 	atomic_set(&fs_info->balance_pause_req, 0);
2252 	atomic_set(&fs_info->balance_cancel_req, 0);
2253 	fs_info->balance_ctl = NULL;
2254 	init_waitqueue_head(&fs_info->balance_wait_q);
2255 }
2256 
2257 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2258 {
2259 	struct inode *inode = fs_info->btree_inode;
2260 
2261 	inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2262 	set_nlink(inode, 1);
2263 	/*
2264 	 * we set the i_size on the btree inode to the max possible int.
2265 	 * the real end of the address space is determined by all of
2266 	 * the devices in the system
2267 	 */
2268 	inode->i_size = OFFSET_MAX;
2269 	inode->i_mapping->a_ops = &btree_aops;
2270 
2271 	RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2272 	extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
2273 			    IO_TREE_BTREE_INODE_IO, inode);
2274 	BTRFS_I(inode)->io_tree.track_uptodate = false;
2275 	extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2276 
2277 	BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
2278 	memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2279 	set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2280 	btrfs_insert_inode_hash(inode);
2281 }
2282 
2283 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2284 {
2285 	mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2286 	init_rwsem(&fs_info->dev_replace.rwsem);
2287 	init_waitqueue_head(&fs_info->dev_replace.replace_wait);
2288 }
2289 
2290 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2291 {
2292 	spin_lock_init(&fs_info->qgroup_lock);
2293 	mutex_init(&fs_info->qgroup_ioctl_lock);
2294 	fs_info->qgroup_tree = RB_ROOT;
2295 	INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2296 	fs_info->qgroup_seq = 1;
2297 	fs_info->qgroup_ulist = NULL;
2298 	fs_info->qgroup_rescan_running = false;
2299 	mutex_init(&fs_info->qgroup_rescan_lock);
2300 }
2301 
2302 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2303 		struct btrfs_fs_devices *fs_devices)
2304 {
2305 	u32 max_active = fs_info->thread_pool_size;
2306 	unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2307 
2308 	fs_info->workers =
2309 		btrfs_alloc_workqueue(fs_info, "worker",
2310 				      flags | WQ_HIGHPRI, max_active, 16);
2311 
2312 	fs_info->delalloc_workers =
2313 		btrfs_alloc_workqueue(fs_info, "delalloc",
2314 				      flags, max_active, 2);
2315 
2316 	fs_info->flush_workers =
2317 		btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2318 				      flags, max_active, 0);
2319 
2320 	fs_info->caching_workers =
2321 		btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2322 
2323 	fs_info->fixup_workers =
2324 		btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2325 
2326 	/*
2327 	 * endios are largely parallel and should have a very
2328 	 * low idle thresh
2329 	 */
2330 	fs_info->endio_workers =
2331 		btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2332 	fs_info->endio_meta_workers =
2333 		btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2334 				      max_active, 4);
2335 	fs_info->endio_meta_write_workers =
2336 		btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2337 				      max_active, 2);
2338 	fs_info->endio_raid56_workers =
2339 		btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2340 				      max_active, 4);
2341 	fs_info->rmw_workers =
2342 		btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2343 	fs_info->endio_write_workers =
2344 		btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2345 				      max_active, 2);
2346 	fs_info->endio_freespace_worker =
2347 		btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2348 				      max_active, 0);
2349 	fs_info->delayed_workers =
2350 		btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2351 				      max_active, 0);
2352 	fs_info->readahead_workers =
2353 		btrfs_alloc_workqueue(fs_info, "readahead", flags,
2354 				      max_active, 2);
2355 	fs_info->qgroup_rescan_workers =
2356 		btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2357 	fs_info->discard_ctl.discard_workers =
2358 		alloc_workqueue("btrfs_discard", WQ_UNBOUND | WQ_FREEZABLE, 1);
2359 
2360 	if (!(fs_info->workers && fs_info->delalloc_workers &&
2361 	      fs_info->flush_workers &&
2362 	      fs_info->endio_workers && fs_info->endio_meta_workers &&
2363 	      fs_info->endio_meta_write_workers &&
2364 	      fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2365 	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2366 	      fs_info->caching_workers && fs_info->readahead_workers &&
2367 	      fs_info->fixup_workers && fs_info->delayed_workers &&
2368 	      fs_info->qgroup_rescan_workers &&
2369 	      fs_info->discard_ctl.discard_workers)) {
2370 		return -ENOMEM;
2371 	}
2372 
2373 	return 0;
2374 }
2375 
2376 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2377 {
2378 	struct crypto_shash *csum_shash;
2379 	const char *csum_driver = btrfs_super_csum_driver(csum_type);
2380 
2381 	csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2382 
2383 	if (IS_ERR(csum_shash)) {
2384 		btrfs_err(fs_info, "error allocating %s hash for checksum",
2385 			  csum_driver);
2386 		return PTR_ERR(csum_shash);
2387 	}
2388 
2389 	fs_info->csum_shash = csum_shash;
2390 
2391 	return 0;
2392 }
2393 
2394 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2395 			    struct btrfs_fs_devices *fs_devices)
2396 {
2397 	int ret;
2398 	struct btrfs_root *log_tree_root;
2399 	struct btrfs_super_block *disk_super = fs_info->super_copy;
2400 	u64 bytenr = btrfs_super_log_root(disk_super);
2401 	int level = btrfs_super_log_root_level(disk_super);
2402 
2403 	if (fs_devices->rw_devices == 0) {
2404 		btrfs_warn(fs_info, "log replay required on RO media");
2405 		return -EIO;
2406 	}
2407 
2408 	log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2409 					 GFP_KERNEL);
2410 	if (!log_tree_root)
2411 		return -ENOMEM;
2412 
2413 	log_tree_root->node = read_tree_block(fs_info, bytenr,
2414 					      BTRFS_TREE_LOG_OBJECTID,
2415 					      fs_info->generation + 1, level,
2416 					      NULL);
2417 	if (IS_ERR(log_tree_root->node)) {
2418 		btrfs_warn(fs_info, "failed to read log tree");
2419 		ret = PTR_ERR(log_tree_root->node);
2420 		log_tree_root->node = NULL;
2421 		btrfs_put_root(log_tree_root);
2422 		return ret;
2423 	} else if (!extent_buffer_uptodate(log_tree_root->node)) {
2424 		btrfs_err(fs_info, "failed to read log tree");
2425 		btrfs_put_root(log_tree_root);
2426 		return -EIO;
2427 	}
2428 	/* returns with log_tree_root freed on success */
2429 	ret = btrfs_recover_log_trees(log_tree_root);
2430 	if (ret) {
2431 		btrfs_handle_fs_error(fs_info, ret,
2432 				      "Failed to recover log tree");
2433 		btrfs_put_root(log_tree_root);
2434 		return ret;
2435 	}
2436 
2437 	if (sb_rdonly(fs_info->sb)) {
2438 		ret = btrfs_commit_super(fs_info);
2439 		if (ret)
2440 			return ret;
2441 	}
2442 
2443 	return 0;
2444 }
2445 
2446 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2447 {
2448 	struct btrfs_root *tree_root = fs_info->tree_root;
2449 	struct btrfs_root *root;
2450 	struct btrfs_key location;
2451 	int ret;
2452 
2453 	BUG_ON(!fs_info->tree_root);
2454 
2455 	location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2456 	location.type = BTRFS_ROOT_ITEM_KEY;
2457 	location.offset = 0;
2458 
2459 	root = btrfs_read_tree_root(tree_root, &location);
2460 	if (IS_ERR(root)) {
2461 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2462 			ret = PTR_ERR(root);
2463 			goto out;
2464 		}
2465 	} else {
2466 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2467 		fs_info->extent_root = root;
2468 	}
2469 
2470 	location.objectid = BTRFS_DEV_TREE_OBJECTID;
2471 	root = btrfs_read_tree_root(tree_root, &location);
2472 	if (IS_ERR(root)) {
2473 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2474 			ret = PTR_ERR(root);
2475 			goto out;
2476 		}
2477 	} else {
2478 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2479 		fs_info->dev_root = root;
2480 	}
2481 	/* Initialize fs_info for all devices in any case */
2482 	btrfs_init_devices_late(fs_info);
2483 
2484 	/* If IGNOREDATACSUMS is set don't bother reading the csum root. */
2485 	if (!btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2486 		location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2487 		root = btrfs_read_tree_root(tree_root, &location);
2488 		if (IS_ERR(root)) {
2489 			if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2490 				ret = PTR_ERR(root);
2491 				goto out;
2492 			}
2493 		} else {
2494 			set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2495 			fs_info->csum_root = root;
2496 		}
2497 	}
2498 
2499 	/*
2500 	 * This tree can share blocks with some other fs tree during relocation
2501 	 * and we need a proper setup by btrfs_get_fs_root
2502 	 */
2503 	root = btrfs_get_fs_root(tree_root->fs_info,
2504 				 BTRFS_DATA_RELOC_TREE_OBJECTID, true);
2505 	if (IS_ERR(root)) {
2506 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2507 			ret = PTR_ERR(root);
2508 			goto out;
2509 		}
2510 	} else {
2511 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2512 		fs_info->data_reloc_root = root;
2513 	}
2514 
2515 	location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2516 	root = btrfs_read_tree_root(tree_root, &location);
2517 	if (!IS_ERR(root)) {
2518 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2519 		set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2520 		fs_info->quota_root = root;
2521 	}
2522 
2523 	location.objectid = BTRFS_UUID_TREE_OBJECTID;
2524 	root = btrfs_read_tree_root(tree_root, &location);
2525 	if (IS_ERR(root)) {
2526 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2527 			ret = PTR_ERR(root);
2528 			if (ret != -ENOENT)
2529 				goto out;
2530 		}
2531 	} else {
2532 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2533 		fs_info->uuid_root = root;
2534 	}
2535 
2536 	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2537 		location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2538 		root = btrfs_read_tree_root(tree_root, &location);
2539 		if (IS_ERR(root)) {
2540 			if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2541 				ret = PTR_ERR(root);
2542 				goto out;
2543 			}
2544 		}  else {
2545 			set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2546 			fs_info->free_space_root = root;
2547 		}
2548 	}
2549 
2550 	return 0;
2551 out:
2552 	btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2553 		   location.objectid, ret);
2554 	return ret;
2555 }
2556 
2557 /*
2558  * Real super block validation
2559  * NOTE: super csum type and incompat features will not be checked here.
2560  *
2561  * @sb:		super block to check
2562  * @mirror_num:	the super block number to check its bytenr:
2563  * 		0	the primary (1st) sb
2564  * 		1, 2	2nd and 3rd backup copy
2565  * 	       -1	skip bytenr check
2566  */
2567 static int validate_super(struct btrfs_fs_info *fs_info,
2568 			    struct btrfs_super_block *sb, int mirror_num)
2569 {
2570 	u64 nodesize = btrfs_super_nodesize(sb);
2571 	u64 sectorsize = btrfs_super_sectorsize(sb);
2572 	int ret = 0;
2573 
2574 	if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2575 		btrfs_err(fs_info, "no valid FS found");
2576 		ret = -EINVAL;
2577 	}
2578 	if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2579 		btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2580 				btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2581 		ret = -EINVAL;
2582 	}
2583 	if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2584 		btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2585 				btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2586 		ret = -EINVAL;
2587 	}
2588 	if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2589 		btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2590 				btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2591 		ret = -EINVAL;
2592 	}
2593 	if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2594 		btrfs_err(fs_info, "log_root level too big: %d >= %d",
2595 				btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2596 		ret = -EINVAL;
2597 	}
2598 
2599 	/*
2600 	 * Check sectorsize and nodesize first, other check will need it.
2601 	 * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2602 	 */
2603 	if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2604 	    sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2605 		btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2606 		ret = -EINVAL;
2607 	}
2608 
2609 	/*
2610 	 * For 4K page size, we only support 4K sector size.
2611 	 * For 64K page size, we support read-write for 64K sector size, and
2612 	 * read-only for 4K sector size.
2613 	 */
2614 	if ((PAGE_SIZE == SZ_4K && sectorsize != PAGE_SIZE) ||
2615 	    (PAGE_SIZE == SZ_64K && (sectorsize != SZ_4K &&
2616 				     sectorsize != SZ_64K))) {
2617 		btrfs_err(fs_info,
2618 			"sectorsize %llu not yet supported for page size %lu",
2619 			sectorsize, PAGE_SIZE);
2620 		ret = -EINVAL;
2621 	}
2622 
2623 	if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2624 	    nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2625 		btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2626 		ret = -EINVAL;
2627 	}
2628 	if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2629 		btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2630 			  le32_to_cpu(sb->__unused_leafsize), nodesize);
2631 		ret = -EINVAL;
2632 	}
2633 
2634 	/* Root alignment check */
2635 	if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2636 		btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2637 			   btrfs_super_root(sb));
2638 		ret = -EINVAL;
2639 	}
2640 	if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2641 		btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2642 			   btrfs_super_chunk_root(sb));
2643 		ret = -EINVAL;
2644 	}
2645 	if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2646 		btrfs_warn(fs_info, "log_root block unaligned: %llu",
2647 			   btrfs_super_log_root(sb));
2648 		ret = -EINVAL;
2649 	}
2650 
2651 	if (memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
2652 		   BTRFS_FSID_SIZE)) {
2653 		btrfs_err(fs_info,
2654 		"superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
2655 			fs_info->super_copy->fsid, fs_info->fs_devices->fsid);
2656 		ret = -EINVAL;
2657 	}
2658 
2659 	if (btrfs_fs_incompat(fs_info, METADATA_UUID) &&
2660 	    memcmp(fs_info->fs_devices->metadata_uuid,
2661 		   fs_info->super_copy->metadata_uuid, BTRFS_FSID_SIZE)) {
2662 		btrfs_err(fs_info,
2663 "superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
2664 			fs_info->super_copy->metadata_uuid,
2665 			fs_info->fs_devices->metadata_uuid);
2666 		ret = -EINVAL;
2667 	}
2668 
2669 	if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2670 		   BTRFS_FSID_SIZE) != 0) {
2671 		btrfs_err(fs_info,
2672 			"dev_item UUID does not match metadata fsid: %pU != %pU",
2673 			fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2674 		ret = -EINVAL;
2675 	}
2676 
2677 	/*
2678 	 * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2679 	 * done later
2680 	 */
2681 	if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2682 		btrfs_err(fs_info, "bytes_used is too small %llu",
2683 			  btrfs_super_bytes_used(sb));
2684 		ret = -EINVAL;
2685 	}
2686 	if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2687 		btrfs_err(fs_info, "invalid stripesize %u",
2688 			  btrfs_super_stripesize(sb));
2689 		ret = -EINVAL;
2690 	}
2691 	if (btrfs_super_num_devices(sb) > (1UL << 31))
2692 		btrfs_warn(fs_info, "suspicious number of devices: %llu",
2693 			   btrfs_super_num_devices(sb));
2694 	if (btrfs_super_num_devices(sb) == 0) {
2695 		btrfs_err(fs_info, "number of devices is 0");
2696 		ret = -EINVAL;
2697 	}
2698 
2699 	if (mirror_num >= 0 &&
2700 	    btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2701 		btrfs_err(fs_info, "super offset mismatch %llu != %u",
2702 			  btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2703 		ret = -EINVAL;
2704 	}
2705 
2706 	/*
2707 	 * Obvious sys_chunk_array corruptions, it must hold at least one key
2708 	 * and one chunk
2709 	 */
2710 	if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2711 		btrfs_err(fs_info, "system chunk array too big %u > %u",
2712 			  btrfs_super_sys_array_size(sb),
2713 			  BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2714 		ret = -EINVAL;
2715 	}
2716 	if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2717 			+ sizeof(struct btrfs_chunk)) {
2718 		btrfs_err(fs_info, "system chunk array too small %u < %zu",
2719 			  btrfs_super_sys_array_size(sb),
2720 			  sizeof(struct btrfs_disk_key)
2721 			  + sizeof(struct btrfs_chunk));
2722 		ret = -EINVAL;
2723 	}
2724 
2725 	/*
2726 	 * The generation is a global counter, we'll trust it more than the others
2727 	 * but it's still possible that it's the one that's wrong.
2728 	 */
2729 	if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2730 		btrfs_warn(fs_info,
2731 			"suspicious: generation < chunk_root_generation: %llu < %llu",
2732 			btrfs_super_generation(sb),
2733 			btrfs_super_chunk_root_generation(sb));
2734 	if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2735 	    && btrfs_super_cache_generation(sb) != (u64)-1)
2736 		btrfs_warn(fs_info,
2737 			"suspicious: generation < cache_generation: %llu < %llu",
2738 			btrfs_super_generation(sb),
2739 			btrfs_super_cache_generation(sb));
2740 
2741 	return ret;
2742 }
2743 
2744 /*
2745  * Validation of super block at mount time.
2746  * Some checks already done early at mount time, like csum type and incompat
2747  * flags will be skipped.
2748  */
2749 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2750 {
2751 	return validate_super(fs_info, fs_info->super_copy, 0);
2752 }
2753 
2754 /*
2755  * Validation of super block at write time.
2756  * Some checks like bytenr check will be skipped as their values will be
2757  * overwritten soon.
2758  * Extra checks like csum type and incompat flags will be done here.
2759  */
2760 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2761 				      struct btrfs_super_block *sb)
2762 {
2763 	int ret;
2764 
2765 	ret = validate_super(fs_info, sb, -1);
2766 	if (ret < 0)
2767 		goto out;
2768 	if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2769 		ret = -EUCLEAN;
2770 		btrfs_err(fs_info, "invalid csum type, has %u want %u",
2771 			  btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2772 		goto out;
2773 	}
2774 	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2775 		ret = -EUCLEAN;
2776 		btrfs_err(fs_info,
2777 		"invalid incompat flags, has 0x%llx valid mask 0x%llx",
2778 			  btrfs_super_incompat_flags(sb),
2779 			  (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2780 		goto out;
2781 	}
2782 out:
2783 	if (ret < 0)
2784 		btrfs_err(fs_info,
2785 		"super block corruption detected before writing it to disk");
2786 	return ret;
2787 }
2788 
2789 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2790 {
2791 	int backup_index = find_newest_super_backup(fs_info);
2792 	struct btrfs_super_block *sb = fs_info->super_copy;
2793 	struct btrfs_root *tree_root = fs_info->tree_root;
2794 	bool handle_error = false;
2795 	int ret = 0;
2796 	int i;
2797 
2798 	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2799 		u64 generation;
2800 		int level;
2801 
2802 		if (handle_error) {
2803 			if (!IS_ERR(tree_root->node))
2804 				free_extent_buffer(tree_root->node);
2805 			tree_root->node = NULL;
2806 
2807 			if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2808 				break;
2809 
2810 			free_root_pointers(fs_info, 0);
2811 
2812 			/*
2813 			 * Don't use the log in recovery mode, it won't be
2814 			 * valid
2815 			 */
2816 			btrfs_set_super_log_root(sb, 0);
2817 
2818 			/* We can't trust the free space cache either */
2819 			btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2820 
2821 			ret = read_backup_root(fs_info, i);
2822 			backup_index = ret;
2823 			if (ret < 0)
2824 				return ret;
2825 		}
2826 		generation = btrfs_super_generation(sb);
2827 		level = btrfs_super_root_level(sb);
2828 		tree_root->node = read_tree_block(fs_info, btrfs_super_root(sb),
2829 						  BTRFS_ROOT_TREE_OBJECTID,
2830 						  generation, level, NULL);
2831 		if (IS_ERR(tree_root->node)) {
2832 			handle_error = true;
2833 			ret = PTR_ERR(tree_root->node);
2834 			tree_root->node = NULL;
2835 			btrfs_warn(fs_info, "couldn't read tree root");
2836 			continue;
2837 
2838 		} else if (!extent_buffer_uptodate(tree_root->node)) {
2839 			handle_error = true;
2840 			ret = -EIO;
2841 			btrfs_warn(fs_info, "error while reading tree root");
2842 			continue;
2843 		}
2844 
2845 		btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2846 		tree_root->commit_root = btrfs_root_node(tree_root);
2847 		btrfs_set_root_refs(&tree_root->root_item, 1);
2848 
2849 		/*
2850 		 * No need to hold btrfs_root::objectid_mutex since the fs
2851 		 * hasn't been fully initialised and we are the only user
2852 		 */
2853 		ret = btrfs_init_root_free_objectid(tree_root);
2854 		if (ret < 0) {
2855 			handle_error = true;
2856 			continue;
2857 		}
2858 
2859 		ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
2860 
2861 		ret = btrfs_read_roots(fs_info);
2862 		if (ret < 0) {
2863 			handle_error = true;
2864 			continue;
2865 		}
2866 
2867 		/* All successful */
2868 		fs_info->generation = generation;
2869 		fs_info->last_trans_committed = generation;
2870 
2871 		/* Always begin writing backup roots after the one being used */
2872 		if (backup_index < 0) {
2873 			fs_info->backup_root_index = 0;
2874 		} else {
2875 			fs_info->backup_root_index = backup_index + 1;
2876 			fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
2877 		}
2878 		break;
2879 	}
2880 
2881 	return ret;
2882 }
2883 
2884 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
2885 {
2886 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2887 	INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2888 	INIT_LIST_HEAD(&fs_info->trans_list);
2889 	INIT_LIST_HEAD(&fs_info->dead_roots);
2890 	INIT_LIST_HEAD(&fs_info->delayed_iputs);
2891 	INIT_LIST_HEAD(&fs_info->delalloc_roots);
2892 	INIT_LIST_HEAD(&fs_info->caching_block_groups);
2893 	spin_lock_init(&fs_info->delalloc_root_lock);
2894 	spin_lock_init(&fs_info->trans_lock);
2895 	spin_lock_init(&fs_info->fs_roots_radix_lock);
2896 	spin_lock_init(&fs_info->delayed_iput_lock);
2897 	spin_lock_init(&fs_info->defrag_inodes_lock);
2898 	spin_lock_init(&fs_info->super_lock);
2899 	spin_lock_init(&fs_info->buffer_lock);
2900 	spin_lock_init(&fs_info->unused_bgs_lock);
2901 	spin_lock_init(&fs_info->treelog_bg_lock);
2902 	rwlock_init(&fs_info->tree_mod_log_lock);
2903 	mutex_init(&fs_info->unused_bg_unpin_mutex);
2904 	mutex_init(&fs_info->reclaim_bgs_lock);
2905 	mutex_init(&fs_info->reloc_mutex);
2906 	mutex_init(&fs_info->delalloc_root_mutex);
2907 	mutex_init(&fs_info->zoned_meta_io_lock);
2908 	seqlock_init(&fs_info->profiles_lock);
2909 
2910 	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2911 	INIT_LIST_HEAD(&fs_info->space_info);
2912 	INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2913 	INIT_LIST_HEAD(&fs_info->unused_bgs);
2914 	INIT_LIST_HEAD(&fs_info->reclaim_bgs);
2915 #ifdef CONFIG_BTRFS_DEBUG
2916 	INIT_LIST_HEAD(&fs_info->allocated_roots);
2917 	INIT_LIST_HEAD(&fs_info->allocated_ebs);
2918 	spin_lock_init(&fs_info->eb_leak_lock);
2919 #endif
2920 	extent_map_tree_init(&fs_info->mapping_tree);
2921 	btrfs_init_block_rsv(&fs_info->global_block_rsv,
2922 			     BTRFS_BLOCK_RSV_GLOBAL);
2923 	btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2924 	btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2925 	btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2926 	btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2927 			     BTRFS_BLOCK_RSV_DELOPS);
2928 	btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
2929 			     BTRFS_BLOCK_RSV_DELREFS);
2930 
2931 	atomic_set(&fs_info->async_delalloc_pages, 0);
2932 	atomic_set(&fs_info->defrag_running, 0);
2933 	atomic_set(&fs_info->reada_works_cnt, 0);
2934 	atomic_set(&fs_info->nr_delayed_iputs, 0);
2935 	atomic64_set(&fs_info->tree_mod_seq, 0);
2936 	fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2937 	fs_info->metadata_ratio = 0;
2938 	fs_info->defrag_inodes = RB_ROOT;
2939 	atomic64_set(&fs_info->free_chunk_space, 0);
2940 	fs_info->tree_mod_log = RB_ROOT;
2941 	fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2942 	fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2943 	/* readahead state */
2944 	INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2945 	spin_lock_init(&fs_info->reada_lock);
2946 	btrfs_init_ref_verify(fs_info);
2947 
2948 	fs_info->thread_pool_size = min_t(unsigned long,
2949 					  num_online_cpus() + 2, 8);
2950 
2951 	INIT_LIST_HEAD(&fs_info->ordered_roots);
2952 	spin_lock_init(&fs_info->ordered_root_lock);
2953 
2954 	btrfs_init_scrub(fs_info);
2955 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2956 	fs_info->check_integrity_print_mask = 0;
2957 #endif
2958 	btrfs_init_balance(fs_info);
2959 	btrfs_init_async_reclaim_work(fs_info);
2960 
2961 	spin_lock_init(&fs_info->block_group_cache_lock);
2962 	fs_info->block_group_cache_tree = RB_ROOT;
2963 	fs_info->first_logical_byte = (u64)-1;
2964 
2965 	extent_io_tree_init(fs_info, &fs_info->excluded_extents,
2966 			    IO_TREE_FS_EXCLUDED_EXTENTS, NULL);
2967 	set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2968 
2969 	mutex_init(&fs_info->ordered_operations_mutex);
2970 	mutex_init(&fs_info->tree_log_mutex);
2971 	mutex_init(&fs_info->chunk_mutex);
2972 	mutex_init(&fs_info->transaction_kthread_mutex);
2973 	mutex_init(&fs_info->cleaner_mutex);
2974 	mutex_init(&fs_info->ro_block_group_mutex);
2975 	init_rwsem(&fs_info->commit_root_sem);
2976 	init_rwsem(&fs_info->cleanup_work_sem);
2977 	init_rwsem(&fs_info->subvol_sem);
2978 	sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2979 
2980 	btrfs_init_dev_replace_locks(fs_info);
2981 	btrfs_init_qgroup(fs_info);
2982 	btrfs_discard_init(fs_info);
2983 
2984 	btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2985 	btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2986 
2987 	init_waitqueue_head(&fs_info->transaction_throttle);
2988 	init_waitqueue_head(&fs_info->transaction_wait);
2989 	init_waitqueue_head(&fs_info->transaction_blocked_wait);
2990 	init_waitqueue_head(&fs_info->async_submit_wait);
2991 	init_waitqueue_head(&fs_info->delayed_iputs_wait);
2992 
2993 	/* Usable values until the real ones are cached from the superblock */
2994 	fs_info->nodesize = 4096;
2995 	fs_info->sectorsize = 4096;
2996 	fs_info->sectorsize_bits = ilog2(4096);
2997 	fs_info->stripesize = 4096;
2998 
2999 	spin_lock_init(&fs_info->swapfile_pins_lock);
3000 	fs_info->swapfile_pins = RB_ROOT;
3001 
3002 	fs_info->send_in_progress = 0;
3003 
3004 	fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH;
3005 	INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work);
3006 }
3007 
3008 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
3009 {
3010 	int ret;
3011 
3012 	fs_info->sb = sb;
3013 	sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
3014 	sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
3015 
3016 	ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
3017 	if (ret)
3018 		return ret;
3019 
3020 	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
3021 	if (ret)
3022 		return ret;
3023 
3024 	fs_info->dirty_metadata_batch = PAGE_SIZE *
3025 					(1 + ilog2(nr_cpu_ids));
3026 
3027 	ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
3028 	if (ret)
3029 		return ret;
3030 
3031 	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
3032 			GFP_KERNEL);
3033 	if (ret)
3034 		return ret;
3035 
3036 	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
3037 					GFP_KERNEL);
3038 	if (!fs_info->delayed_root)
3039 		return -ENOMEM;
3040 	btrfs_init_delayed_root(fs_info->delayed_root);
3041 
3042 	if (sb_rdonly(sb))
3043 		set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
3044 
3045 	return btrfs_alloc_stripe_hash_table(fs_info);
3046 }
3047 
3048 static int btrfs_uuid_rescan_kthread(void *data)
3049 {
3050 	struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3051 	int ret;
3052 
3053 	/*
3054 	 * 1st step is to iterate through the existing UUID tree and
3055 	 * to delete all entries that contain outdated data.
3056 	 * 2nd step is to add all missing entries to the UUID tree.
3057 	 */
3058 	ret = btrfs_uuid_tree_iterate(fs_info);
3059 	if (ret < 0) {
3060 		if (ret != -EINTR)
3061 			btrfs_warn(fs_info, "iterating uuid_tree failed %d",
3062 				   ret);
3063 		up(&fs_info->uuid_tree_rescan_sem);
3064 		return ret;
3065 	}
3066 	return btrfs_uuid_scan_kthread(data);
3067 }
3068 
3069 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3070 {
3071 	struct task_struct *task;
3072 
3073 	down(&fs_info->uuid_tree_rescan_sem);
3074 	task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3075 	if (IS_ERR(task)) {
3076 		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
3077 		btrfs_warn(fs_info, "failed to start uuid_rescan task");
3078 		up(&fs_info->uuid_tree_rescan_sem);
3079 		return PTR_ERR(task);
3080 	}
3081 
3082 	return 0;
3083 }
3084 
3085 /*
3086  * Some options only have meaning at mount time and shouldn't persist across
3087  * remounts, or be displayed. Clear these at the end of mount and remount
3088  * code paths.
3089  */
3090 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
3091 {
3092 	btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3093 	btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE);
3094 }
3095 
3096 /*
3097  * Mounting logic specific to read-write file systems. Shared by open_ctree
3098  * and btrfs_remount when remounting from read-only to read-write.
3099  */
3100 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
3101 {
3102 	int ret;
3103 	const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
3104 	bool clear_free_space_tree = false;
3105 
3106 	if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3107 	    btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3108 		clear_free_space_tree = true;
3109 	} else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3110 		   !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3111 		btrfs_warn(fs_info, "free space tree is invalid");
3112 		clear_free_space_tree = true;
3113 	}
3114 
3115 	if (clear_free_space_tree) {
3116 		btrfs_info(fs_info, "clearing free space tree");
3117 		ret = btrfs_clear_free_space_tree(fs_info);
3118 		if (ret) {
3119 			btrfs_warn(fs_info,
3120 				   "failed to clear free space tree: %d", ret);
3121 			goto out;
3122 		}
3123 	}
3124 
3125 	/*
3126 	 * btrfs_find_orphan_roots() is responsible for finding all the dead
3127 	 * roots (with 0 refs), flag them with BTRFS_ROOT_DEAD_TREE and load
3128 	 * them into the fs_info->fs_roots_radix tree. This must be done before
3129 	 * calling btrfs_orphan_cleanup() on the tree root. If we don't do it
3130 	 * first, then btrfs_orphan_cleanup() will delete a dead root's orphan
3131 	 * item before the root's tree is deleted - this means that if we unmount
3132 	 * or crash before the deletion completes, on the next mount we will not
3133 	 * delete what remains of the tree because the orphan item does not
3134 	 * exists anymore, which is what tells us we have a pending deletion.
3135 	 */
3136 	ret = btrfs_find_orphan_roots(fs_info);
3137 	if (ret)
3138 		goto out;
3139 
3140 	ret = btrfs_cleanup_fs_roots(fs_info);
3141 	if (ret)
3142 		goto out;
3143 
3144 	down_read(&fs_info->cleanup_work_sem);
3145 	if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3146 	    (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3147 		up_read(&fs_info->cleanup_work_sem);
3148 		goto out;
3149 	}
3150 	up_read(&fs_info->cleanup_work_sem);
3151 
3152 	mutex_lock(&fs_info->cleaner_mutex);
3153 	ret = btrfs_recover_relocation(fs_info->tree_root);
3154 	mutex_unlock(&fs_info->cleaner_mutex);
3155 	if (ret < 0) {
3156 		btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
3157 		goto out;
3158 	}
3159 
3160 	if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3161 	    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3162 		btrfs_info(fs_info, "creating free space tree");
3163 		ret = btrfs_create_free_space_tree(fs_info);
3164 		if (ret) {
3165 			btrfs_warn(fs_info,
3166 				"failed to create free space tree: %d", ret);
3167 			goto out;
3168 		}
3169 	}
3170 
3171 	if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3172 		ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3173 		if (ret)
3174 			goto out;
3175 	}
3176 
3177 	ret = btrfs_resume_balance_async(fs_info);
3178 	if (ret)
3179 		goto out;
3180 
3181 	ret = btrfs_resume_dev_replace_async(fs_info);
3182 	if (ret) {
3183 		btrfs_warn(fs_info, "failed to resume dev_replace");
3184 		goto out;
3185 	}
3186 
3187 	btrfs_qgroup_rescan_resume(fs_info);
3188 
3189 	if (!fs_info->uuid_root) {
3190 		btrfs_info(fs_info, "creating UUID tree");
3191 		ret = btrfs_create_uuid_tree(fs_info);
3192 		if (ret) {
3193 			btrfs_warn(fs_info,
3194 				   "failed to create the UUID tree %d", ret);
3195 			goto out;
3196 		}
3197 	}
3198 
3199 out:
3200 	return ret;
3201 }
3202 
3203 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
3204 		      char *options)
3205 {
3206 	u32 sectorsize;
3207 	u32 nodesize;
3208 	u32 stripesize;
3209 	u64 generation;
3210 	u64 features;
3211 	u16 csum_type;
3212 	struct btrfs_super_block *disk_super;
3213 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3214 	struct btrfs_root *tree_root;
3215 	struct btrfs_root *chunk_root;
3216 	int ret;
3217 	int err = -EINVAL;
3218 	int level;
3219 
3220 	ret = init_mount_fs_info(fs_info, sb);
3221 	if (ret) {
3222 		err = ret;
3223 		goto fail;
3224 	}
3225 
3226 	/* These need to be init'ed before we start creating inodes and such. */
3227 	tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3228 				     GFP_KERNEL);
3229 	fs_info->tree_root = tree_root;
3230 	chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3231 				      GFP_KERNEL);
3232 	fs_info->chunk_root = chunk_root;
3233 	if (!tree_root || !chunk_root) {
3234 		err = -ENOMEM;
3235 		goto fail;
3236 	}
3237 
3238 	fs_info->btree_inode = new_inode(sb);
3239 	if (!fs_info->btree_inode) {
3240 		err = -ENOMEM;
3241 		goto fail;
3242 	}
3243 	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
3244 	btrfs_init_btree_inode(fs_info);
3245 
3246 	invalidate_bdev(fs_devices->latest_bdev);
3247 
3248 	/*
3249 	 * Read super block and check the signature bytes only
3250 	 */
3251 	disk_super = btrfs_read_dev_super(fs_devices->latest_bdev);
3252 	if (IS_ERR(disk_super)) {
3253 		err = PTR_ERR(disk_super);
3254 		goto fail_alloc;
3255 	}
3256 
3257 	/*
3258 	 * Verify the type first, if that or the checksum value are
3259 	 * corrupted, we'll find out
3260 	 */
3261 	csum_type = btrfs_super_csum_type(disk_super);
3262 	if (!btrfs_supported_super_csum(csum_type)) {
3263 		btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3264 			  csum_type);
3265 		err = -EINVAL;
3266 		btrfs_release_disk_super(disk_super);
3267 		goto fail_alloc;
3268 	}
3269 
3270 	fs_info->csum_size = btrfs_super_csum_size(disk_super);
3271 
3272 	ret = btrfs_init_csum_hash(fs_info, csum_type);
3273 	if (ret) {
3274 		err = ret;
3275 		btrfs_release_disk_super(disk_super);
3276 		goto fail_alloc;
3277 	}
3278 
3279 	/*
3280 	 * We want to check superblock checksum, the type is stored inside.
3281 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3282 	 */
3283 	if (btrfs_check_super_csum(fs_info, (u8 *)disk_super)) {
3284 		btrfs_err(fs_info, "superblock checksum mismatch");
3285 		err = -EINVAL;
3286 		btrfs_release_disk_super(disk_super);
3287 		goto fail_alloc;
3288 	}
3289 
3290 	/*
3291 	 * super_copy is zeroed at allocation time and we never touch the
3292 	 * following bytes up to INFO_SIZE, the checksum is calculated from
3293 	 * the whole block of INFO_SIZE
3294 	 */
3295 	memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3296 	btrfs_release_disk_super(disk_super);
3297 
3298 	disk_super = fs_info->super_copy;
3299 
3300 
3301 	features = btrfs_super_flags(disk_super);
3302 	if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
3303 		features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
3304 		btrfs_set_super_flags(disk_super, features);
3305 		btrfs_info(fs_info,
3306 			"found metadata UUID change in progress flag, clearing");
3307 	}
3308 
3309 	memcpy(fs_info->super_for_commit, fs_info->super_copy,
3310 	       sizeof(*fs_info->super_for_commit));
3311 
3312 	ret = btrfs_validate_mount_super(fs_info);
3313 	if (ret) {
3314 		btrfs_err(fs_info, "superblock contains fatal errors");
3315 		err = -EINVAL;
3316 		goto fail_alloc;
3317 	}
3318 
3319 	if (!btrfs_super_root(disk_super))
3320 		goto fail_alloc;
3321 
3322 	/* check FS state, whether FS is broken. */
3323 	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3324 		set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
3325 
3326 	/*
3327 	 * In the long term, we'll store the compression type in the super
3328 	 * block, and it'll be used for per file compression control.
3329 	 */
3330 	fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
3331 
3332 	ret = btrfs_parse_options(fs_info, options, sb->s_flags);
3333 	if (ret) {
3334 		err = ret;
3335 		goto fail_alloc;
3336 	}
3337 
3338 	features = btrfs_super_incompat_flags(disk_super) &
3339 		~BTRFS_FEATURE_INCOMPAT_SUPP;
3340 	if (features) {
3341 		btrfs_err(fs_info,
3342 		    "cannot mount because of unsupported optional features (%llx)",
3343 		    features);
3344 		err = -EINVAL;
3345 		goto fail_alloc;
3346 	}
3347 
3348 	features = btrfs_super_incompat_flags(disk_super);
3349 	features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3350 	if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3351 		features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3352 	else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3353 		features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3354 
3355 	if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
3356 		btrfs_info(fs_info, "has skinny extents");
3357 
3358 	/*
3359 	 * flag our filesystem as having big metadata blocks if
3360 	 * they are bigger than the page size
3361 	 */
3362 	if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
3363 		if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
3364 			btrfs_info(fs_info,
3365 				"flagging fs with big metadata feature");
3366 		features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3367 	}
3368 
3369 	nodesize = btrfs_super_nodesize(disk_super);
3370 	sectorsize = btrfs_super_sectorsize(disk_super);
3371 	stripesize = sectorsize;
3372 	fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3373 	fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3374 
3375 	/* Cache block sizes */
3376 	fs_info->nodesize = nodesize;
3377 	fs_info->sectorsize = sectorsize;
3378 	fs_info->sectorsize_bits = ilog2(sectorsize);
3379 	fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3380 	fs_info->stripesize = stripesize;
3381 
3382 	/*
3383 	 * mixed block groups end up with duplicate but slightly offset
3384 	 * extent buffers for the same range.  It leads to corruptions
3385 	 */
3386 	if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3387 	    (sectorsize != nodesize)) {
3388 		btrfs_err(fs_info,
3389 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3390 			nodesize, sectorsize);
3391 		goto fail_alloc;
3392 	}
3393 
3394 	/*
3395 	 * Needn't use the lock because there is no other task which will
3396 	 * update the flag.
3397 	 */
3398 	btrfs_set_super_incompat_flags(disk_super, features);
3399 
3400 	features = btrfs_super_compat_ro_flags(disk_super) &
3401 		~BTRFS_FEATURE_COMPAT_RO_SUPP;
3402 	if (!sb_rdonly(sb) && features) {
3403 		btrfs_err(fs_info,
3404 	"cannot mount read-write because of unsupported optional features (%llx)",
3405 		       features);
3406 		err = -EINVAL;
3407 		goto fail_alloc;
3408 	}
3409 
3410 	/* For 4K sector size support, it's only read-only */
3411 	if (PAGE_SIZE == SZ_64K && sectorsize == SZ_4K) {
3412 		if (!sb_rdonly(sb) || btrfs_super_log_root(disk_super)) {
3413 			btrfs_err(fs_info,
3414 	"subpage sectorsize %u only supported read-only for page size %lu",
3415 				sectorsize, PAGE_SIZE);
3416 			err = -EINVAL;
3417 			goto fail_alloc;
3418 		}
3419 	}
3420 
3421 	ret = btrfs_init_workqueues(fs_info, fs_devices);
3422 	if (ret) {
3423 		err = ret;
3424 		goto fail_sb_buffer;
3425 	}
3426 
3427 	sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3428 	sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3429 
3430 	sb->s_blocksize = sectorsize;
3431 	sb->s_blocksize_bits = blksize_bits(sectorsize);
3432 	memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3433 
3434 	mutex_lock(&fs_info->chunk_mutex);
3435 	ret = btrfs_read_sys_array(fs_info);
3436 	mutex_unlock(&fs_info->chunk_mutex);
3437 	if (ret) {
3438 		btrfs_err(fs_info, "failed to read the system array: %d", ret);
3439 		goto fail_sb_buffer;
3440 	}
3441 
3442 	generation = btrfs_super_chunk_root_generation(disk_super);
3443 	level = btrfs_super_chunk_root_level(disk_super);
3444 
3445 	chunk_root->node = read_tree_block(fs_info,
3446 					   btrfs_super_chunk_root(disk_super),
3447 					   BTRFS_CHUNK_TREE_OBJECTID,
3448 					   generation, level, NULL);
3449 	if (IS_ERR(chunk_root->node) ||
3450 	    !extent_buffer_uptodate(chunk_root->node)) {
3451 		btrfs_err(fs_info, "failed to read chunk root");
3452 		if (!IS_ERR(chunk_root->node))
3453 			free_extent_buffer(chunk_root->node);
3454 		chunk_root->node = NULL;
3455 		goto fail_tree_roots;
3456 	}
3457 	btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
3458 	chunk_root->commit_root = btrfs_root_node(chunk_root);
3459 
3460 	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3461 			   offsetof(struct btrfs_header, chunk_tree_uuid),
3462 			   BTRFS_UUID_SIZE);
3463 
3464 	ret = btrfs_read_chunk_tree(fs_info);
3465 	if (ret) {
3466 		btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3467 		goto fail_tree_roots;
3468 	}
3469 
3470 	/*
3471 	 * At this point we know all the devices that make this filesystem,
3472 	 * including the seed devices but we don't know yet if the replace
3473 	 * target is required. So free devices that are not part of this
3474 	 * filesystem but skip the replace traget device which is checked
3475 	 * below in btrfs_init_dev_replace().
3476 	 */
3477 	btrfs_free_extra_devids(fs_devices);
3478 	if (!fs_devices->latest_bdev) {
3479 		btrfs_err(fs_info, "failed to read devices");
3480 		goto fail_tree_roots;
3481 	}
3482 
3483 	ret = init_tree_roots(fs_info);
3484 	if (ret)
3485 		goto fail_tree_roots;
3486 
3487 	/*
3488 	 * Get zone type information of zoned block devices. This will also
3489 	 * handle emulation of a zoned filesystem if a regular device has the
3490 	 * zoned incompat feature flag set.
3491 	 */
3492 	ret = btrfs_get_dev_zone_info_all_devices(fs_info);
3493 	if (ret) {
3494 		btrfs_err(fs_info,
3495 			  "zoned: failed to read device zone info: %d",
3496 			  ret);
3497 		goto fail_block_groups;
3498 	}
3499 
3500 	/*
3501 	 * If we have a uuid root and we're not being told to rescan we need to
3502 	 * check the generation here so we can set the
3503 	 * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
3504 	 * transaction during a balance or the log replay without updating the
3505 	 * uuid generation, and then if we crash we would rescan the uuid tree,
3506 	 * even though it was perfectly fine.
3507 	 */
3508 	if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3509 	    fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3510 		set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3511 
3512 	ret = btrfs_verify_dev_extents(fs_info);
3513 	if (ret) {
3514 		btrfs_err(fs_info,
3515 			  "failed to verify dev extents against chunks: %d",
3516 			  ret);
3517 		goto fail_block_groups;
3518 	}
3519 	ret = btrfs_recover_balance(fs_info);
3520 	if (ret) {
3521 		btrfs_err(fs_info, "failed to recover balance: %d", ret);
3522 		goto fail_block_groups;
3523 	}
3524 
3525 	ret = btrfs_init_dev_stats(fs_info);
3526 	if (ret) {
3527 		btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3528 		goto fail_block_groups;
3529 	}
3530 
3531 	ret = btrfs_init_dev_replace(fs_info);
3532 	if (ret) {
3533 		btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3534 		goto fail_block_groups;
3535 	}
3536 
3537 	ret = btrfs_check_zoned_mode(fs_info);
3538 	if (ret) {
3539 		btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3540 			  ret);
3541 		goto fail_block_groups;
3542 	}
3543 
3544 	ret = btrfs_sysfs_add_fsid(fs_devices);
3545 	if (ret) {
3546 		btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3547 				ret);
3548 		goto fail_block_groups;
3549 	}
3550 
3551 	ret = btrfs_sysfs_add_mounted(fs_info);
3552 	if (ret) {
3553 		btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3554 		goto fail_fsdev_sysfs;
3555 	}
3556 
3557 	ret = btrfs_init_space_info(fs_info);
3558 	if (ret) {
3559 		btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3560 		goto fail_sysfs;
3561 	}
3562 
3563 	ret = btrfs_read_block_groups(fs_info);
3564 	if (ret) {
3565 		btrfs_err(fs_info, "failed to read block groups: %d", ret);
3566 		goto fail_sysfs;
3567 	}
3568 
3569 	if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
3570 		btrfs_warn(fs_info,
3571 		"writable mount is not allowed due to too many missing devices");
3572 		goto fail_sysfs;
3573 	}
3574 
3575 	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3576 					       "btrfs-cleaner");
3577 	if (IS_ERR(fs_info->cleaner_kthread))
3578 		goto fail_sysfs;
3579 
3580 	fs_info->transaction_kthread = kthread_run(transaction_kthread,
3581 						   tree_root,
3582 						   "btrfs-transaction");
3583 	if (IS_ERR(fs_info->transaction_kthread))
3584 		goto fail_cleaner;
3585 
3586 	if (!btrfs_test_opt(fs_info, NOSSD) &&
3587 	    !fs_info->fs_devices->rotating) {
3588 		btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3589 	}
3590 
3591 	/*
3592 	 * Mount does not set all options immediately, we can do it now and do
3593 	 * not have to wait for transaction commit
3594 	 */
3595 	btrfs_apply_pending_changes(fs_info);
3596 
3597 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3598 	if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3599 		ret = btrfsic_mount(fs_info, fs_devices,
3600 				    btrfs_test_opt(fs_info,
3601 					CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3602 				    1 : 0,
3603 				    fs_info->check_integrity_print_mask);
3604 		if (ret)
3605 			btrfs_warn(fs_info,
3606 				"failed to initialize integrity check module: %d",
3607 				ret);
3608 	}
3609 #endif
3610 	ret = btrfs_read_qgroup_config(fs_info);
3611 	if (ret)
3612 		goto fail_trans_kthread;
3613 
3614 	if (btrfs_build_ref_tree(fs_info))
3615 		btrfs_err(fs_info, "couldn't build ref tree");
3616 
3617 	/* do not make disk changes in broken FS or nologreplay is given */
3618 	if (btrfs_super_log_root(disk_super) != 0 &&
3619 	    !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3620 		btrfs_info(fs_info, "start tree-log replay");
3621 		ret = btrfs_replay_log(fs_info, fs_devices);
3622 		if (ret) {
3623 			err = ret;
3624 			goto fail_qgroup;
3625 		}
3626 	}
3627 
3628 	fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3629 	if (IS_ERR(fs_info->fs_root)) {
3630 		err = PTR_ERR(fs_info->fs_root);
3631 		btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3632 		fs_info->fs_root = NULL;
3633 		goto fail_qgroup;
3634 	}
3635 
3636 	if (sb_rdonly(sb))
3637 		goto clear_oneshot;
3638 
3639 	ret = btrfs_start_pre_rw_mount(fs_info);
3640 	if (ret) {
3641 		close_ctree(fs_info);
3642 		return ret;
3643 	}
3644 	btrfs_discard_resume(fs_info);
3645 
3646 	if (fs_info->uuid_root &&
3647 	    (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3648 	     fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3649 		btrfs_info(fs_info, "checking UUID tree");
3650 		ret = btrfs_check_uuid_tree(fs_info);
3651 		if (ret) {
3652 			btrfs_warn(fs_info,
3653 				"failed to check the UUID tree: %d", ret);
3654 			close_ctree(fs_info);
3655 			return ret;
3656 		}
3657 	}
3658 
3659 	set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3660 
3661 clear_oneshot:
3662 	btrfs_clear_oneshot_options(fs_info);
3663 	return 0;
3664 
3665 fail_qgroup:
3666 	btrfs_free_qgroup_config(fs_info);
3667 fail_trans_kthread:
3668 	kthread_stop(fs_info->transaction_kthread);
3669 	btrfs_cleanup_transaction(fs_info);
3670 	btrfs_free_fs_roots(fs_info);
3671 fail_cleaner:
3672 	kthread_stop(fs_info->cleaner_kthread);
3673 
3674 	/*
3675 	 * make sure we're done with the btree inode before we stop our
3676 	 * kthreads
3677 	 */
3678 	filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3679 
3680 fail_sysfs:
3681 	btrfs_sysfs_remove_mounted(fs_info);
3682 
3683 fail_fsdev_sysfs:
3684 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3685 
3686 fail_block_groups:
3687 	btrfs_put_block_group_cache(fs_info);
3688 
3689 fail_tree_roots:
3690 	if (fs_info->data_reloc_root)
3691 		btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3692 	free_root_pointers(fs_info, true);
3693 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3694 
3695 fail_sb_buffer:
3696 	btrfs_stop_all_workers(fs_info);
3697 	btrfs_free_block_groups(fs_info);
3698 fail_alloc:
3699 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
3700 
3701 	iput(fs_info->btree_inode);
3702 fail:
3703 	btrfs_close_devices(fs_info->fs_devices);
3704 	return err;
3705 }
3706 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3707 
3708 static void btrfs_end_super_write(struct bio *bio)
3709 {
3710 	struct btrfs_device *device = bio->bi_private;
3711 	struct bio_vec *bvec;
3712 	struct bvec_iter_all iter_all;
3713 	struct page *page;
3714 
3715 	bio_for_each_segment_all(bvec, bio, iter_all) {
3716 		page = bvec->bv_page;
3717 
3718 		if (bio->bi_status) {
3719 			btrfs_warn_rl_in_rcu(device->fs_info,
3720 				"lost page write due to IO error on %s (%d)",
3721 				rcu_str_deref(device->name),
3722 				blk_status_to_errno(bio->bi_status));
3723 			ClearPageUptodate(page);
3724 			SetPageError(page);
3725 			btrfs_dev_stat_inc_and_print(device,
3726 						     BTRFS_DEV_STAT_WRITE_ERRS);
3727 		} else {
3728 			SetPageUptodate(page);
3729 		}
3730 
3731 		put_page(page);
3732 		unlock_page(page);
3733 	}
3734 
3735 	bio_put(bio);
3736 }
3737 
3738 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3739 						   int copy_num)
3740 {
3741 	struct btrfs_super_block *super;
3742 	struct page *page;
3743 	u64 bytenr, bytenr_orig;
3744 	struct address_space *mapping = bdev->bd_inode->i_mapping;
3745 	int ret;
3746 
3747 	bytenr_orig = btrfs_sb_offset(copy_num);
3748 	ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3749 	if (ret == -ENOENT)
3750 		return ERR_PTR(-EINVAL);
3751 	else if (ret)
3752 		return ERR_PTR(ret);
3753 
3754 	if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3755 		return ERR_PTR(-EINVAL);
3756 
3757 	page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
3758 	if (IS_ERR(page))
3759 		return ERR_CAST(page);
3760 
3761 	super = page_address(page);
3762 	if (btrfs_super_magic(super) != BTRFS_MAGIC) {
3763 		btrfs_release_disk_super(super);
3764 		return ERR_PTR(-ENODATA);
3765 	}
3766 
3767 	if (btrfs_super_bytenr(super) != bytenr_orig) {
3768 		btrfs_release_disk_super(super);
3769 		return ERR_PTR(-EINVAL);
3770 	}
3771 
3772 	return super;
3773 }
3774 
3775 
3776 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
3777 {
3778 	struct btrfs_super_block *super, *latest = NULL;
3779 	int i;
3780 	u64 transid = 0;
3781 
3782 	/* we would like to check all the supers, but that would make
3783 	 * a btrfs mount succeed after a mkfs from a different FS.
3784 	 * So, we need to add a special mount option to scan for
3785 	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3786 	 */
3787 	for (i = 0; i < 1; i++) {
3788 		super = btrfs_read_dev_one_super(bdev, i);
3789 		if (IS_ERR(super))
3790 			continue;
3791 
3792 		if (!latest || btrfs_super_generation(super) > transid) {
3793 			if (latest)
3794 				btrfs_release_disk_super(super);
3795 
3796 			latest = super;
3797 			transid = btrfs_super_generation(super);
3798 		}
3799 	}
3800 
3801 	return super;
3802 }
3803 
3804 /*
3805  * Write superblock @sb to the @device. Do not wait for completion, all the
3806  * pages we use for writing are locked.
3807  *
3808  * Write @max_mirrors copies of the superblock, where 0 means default that fit
3809  * the expected device size at commit time. Note that max_mirrors must be
3810  * same for write and wait phases.
3811  *
3812  * Return number of errors when page is not found or submission fails.
3813  */
3814 static int write_dev_supers(struct btrfs_device *device,
3815 			    struct btrfs_super_block *sb, int max_mirrors)
3816 {
3817 	struct btrfs_fs_info *fs_info = device->fs_info;
3818 	struct address_space *mapping = device->bdev->bd_inode->i_mapping;
3819 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
3820 	int i;
3821 	int errors = 0;
3822 	int ret;
3823 	u64 bytenr, bytenr_orig;
3824 
3825 	if (max_mirrors == 0)
3826 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3827 
3828 	shash->tfm = fs_info->csum_shash;
3829 
3830 	for (i = 0; i < max_mirrors; i++) {
3831 		struct page *page;
3832 		struct bio *bio;
3833 		struct btrfs_super_block *disk_super;
3834 
3835 		bytenr_orig = btrfs_sb_offset(i);
3836 		ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
3837 		if (ret == -ENOENT) {
3838 			continue;
3839 		} else if (ret < 0) {
3840 			btrfs_err(device->fs_info,
3841 				"couldn't get super block location for mirror %d",
3842 				i);
3843 			errors++;
3844 			continue;
3845 		}
3846 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3847 		    device->commit_total_bytes)
3848 			break;
3849 
3850 		btrfs_set_super_bytenr(sb, bytenr_orig);
3851 
3852 		crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
3853 				    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
3854 				    sb->csum);
3855 
3856 		page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
3857 					   GFP_NOFS);
3858 		if (!page) {
3859 			btrfs_err(device->fs_info,
3860 			    "couldn't get super block page for bytenr %llu",
3861 			    bytenr);
3862 			errors++;
3863 			continue;
3864 		}
3865 
3866 		/* Bump the refcount for wait_dev_supers() */
3867 		get_page(page);
3868 
3869 		disk_super = page_address(page);
3870 		memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
3871 
3872 		/*
3873 		 * Directly use bios here instead of relying on the page cache
3874 		 * to do I/O, so we don't lose the ability to do integrity
3875 		 * checking.
3876 		 */
3877 		bio = bio_alloc(GFP_NOFS, 1);
3878 		bio_set_dev(bio, device->bdev);
3879 		bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
3880 		bio->bi_private = device;
3881 		bio->bi_end_io = btrfs_end_super_write;
3882 		__bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
3883 			       offset_in_page(bytenr));
3884 
3885 		/*
3886 		 * We FUA only the first super block.  The others we allow to
3887 		 * go down lazy and there's a short window where the on-disk
3888 		 * copies might still contain the older version.
3889 		 */
3890 		bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO;
3891 		if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
3892 			bio->bi_opf |= REQ_FUA;
3893 
3894 		btrfsic_submit_bio(bio);
3895 		btrfs_advance_sb_log(device, i);
3896 	}
3897 	return errors < i ? 0 : -1;
3898 }
3899 
3900 /*
3901  * Wait for write completion of superblocks done by write_dev_supers,
3902  * @max_mirrors same for write and wait phases.
3903  *
3904  * Return number of errors when page is not found or not marked up to
3905  * date.
3906  */
3907 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
3908 {
3909 	int i;
3910 	int errors = 0;
3911 	bool primary_failed = false;
3912 	int ret;
3913 	u64 bytenr;
3914 
3915 	if (max_mirrors == 0)
3916 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3917 
3918 	for (i = 0; i < max_mirrors; i++) {
3919 		struct page *page;
3920 
3921 		ret = btrfs_sb_log_location(device, i, READ, &bytenr);
3922 		if (ret == -ENOENT) {
3923 			break;
3924 		} else if (ret < 0) {
3925 			errors++;
3926 			if (i == 0)
3927 				primary_failed = true;
3928 			continue;
3929 		}
3930 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3931 		    device->commit_total_bytes)
3932 			break;
3933 
3934 		page = find_get_page(device->bdev->bd_inode->i_mapping,
3935 				     bytenr >> PAGE_SHIFT);
3936 		if (!page) {
3937 			errors++;
3938 			if (i == 0)
3939 				primary_failed = true;
3940 			continue;
3941 		}
3942 		/* Page is submitted locked and unlocked once the IO completes */
3943 		wait_on_page_locked(page);
3944 		if (PageError(page)) {
3945 			errors++;
3946 			if (i == 0)
3947 				primary_failed = true;
3948 		}
3949 
3950 		/* Drop our reference */
3951 		put_page(page);
3952 
3953 		/* Drop the reference from the writing run */
3954 		put_page(page);
3955 	}
3956 
3957 	/* log error, force error return */
3958 	if (primary_failed) {
3959 		btrfs_err(device->fs_info, "error writing primary super block to device %llu",
3960 			  device->devid);
3961 		return -1;
3962 	}
3963 
3964 	return errors < i ? 0 : -1;
3965 }
3966 
3967 /*
3968  * endio for the write_dev_flush, this will wake anyone waiting
3969  * for the barrier when it is done
3970  */
3971 static void btrfs_end_empty_barrier(struct bio *bio)
3972 {
3973 	complete(bio->bi_private);
3974 }
3975 
3976 /*
3977  * Submit a flush request to the device if it supports it. Error handling is
3978  * done in the waiting counterpart.
3979  */
3980 static void write_dev_flush(struct btrfs_device *device)
3981 {
3982 	struct request_queue *q = bdev_get_queue(device->bdev);
3983 	struct bio *bio = device->flush_bio;
3984 
3985 	if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
3986 		return;
3987 
3988 	bio_reset(bio);
3989 	bio->bi_end_io = btrfs_end_empty_barrier;
3990 	bio_set_dev(bio, device->bdev);
3991 	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
3992 	init_completion(&device->flush_wait);
3993 	bio->bi_private = &device->flush_wait;
3994 
3995 	btrfsic_submit_bio(bio);
3996 	set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3997 }
3998 
3999 /*
4000  * If the flush bio has been submitted by write_dev_flush, wait for it.
4001  */
4002 static blk_status_t wait_dev_flush(struct btrfs_device *device)
4003 {
4004 	struct bio *bio = device->flush_bio;
4005 
4006 	if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
4007 		return BLK_STS_OK;
4008 
4009 	clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4010 	wait_for_completion_io(&device->flush_wait);
4011 
4012 	return bio->bi_status;
4013 }
4014 
4015 static int check_barrier_error(struct btrfs_fs_info *fs_info)
4016 {
4017 	if (!btrfs_check_rw_degradable(fs_info, NULL))
4018 		return -EIO;
4019 	return 0;
4020 }
4021 
4022 /*
4023  * send an empty flush down to each device in parallel,
4024  * then wait for them
4025  */
4026 static int barrier_all_devices(struct btrfs_fs_info *info)
4027 {
4028 	struct list_head *head;
4029 	struct btrfs_device *dev;
4030 	int errors_wait = 0;
4031 	blk_status_t ret;
4032 
4033 	lockdep_assert_held(&info->fs_devices->device_list_mutex);
4034 	/* send down all the barriers */
4035 	head = &info->fs_devices->devices;
4036 	list_for_each_entry(dev, head, dev_list) {
4037 		if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4038 			continue;
4039 		if (!dev->bdev)
4040 			continue;
4041 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4042 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4043 			continue;
4044 
4045 		write_dev_flush(dev);
4046 		dev->last_flush_error = BLK_STS_OK;
4047 	}
4048 
4049 	/* wait for all the barriers */
4050 	list_for_each_entry(dev, head, dev_list) {
4051 		if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4052 			continue;
4053 		if (!dev->bdev) {
4054 			errors_wait++;
4055 			continue;
4056 		}
4057 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4058 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4059 			continue;
4060 
4061 		ret = wait_dev_flush(dev);
4062 		if (ret) {
4063 			dev->last_flush_error = ret;
4064 			btrfs_dev_stat_inc_and_print(dev,
4065 					BTRFS_DEV_STAT_FLUSH_ERRS);
4066 			errors_wait++;
4067 		}
4068 	}
4069 
4070 	if (errors_wait) {
4071 		/*
4072 		 * At some point we need the status of all disks
4073 		 * to arrive at the volume status. So error checking
4074 		 * is being pushed to a separate loop.
4075 		 */
4076 		return check_barrier_error(info);
4077 	}
4078 	return 0;
4079 }
4080 
4081 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
4082 {
4083 	int raid_type;
4084 	int min_tolerated = INT_MAX;
4085 
4086 	if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
4087 	    (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
4088 		min_tolerated = min_t(int, min_tolerated,
4089 				    btrfs_raid_array[BTRFS_RAID_SINGLE].
4090 				    tolerated_failures);
4091 
4092 	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4093 		if (raid_type == BTRFS_RAID_SINGLE)
4094 			continue;
4095 		if (!(flags & btrfs_raid_array[raid_type].bg_flag))
4096 			continue;
4097 		min_tolerated = min_t(int, min_tolerated,
4098 				    btrfs_raid_array[raid_type].
4099 				    tolerated_failures);
4100 	}
4101 
4102 	if (min_tolerated == INT_MAX) {
4103 		pr_warn("BTRFS: unknown raid flag: %llu", flags);
4104 		min_tolerated = 0;
4105 	}
4106 
4107 	return min_tolerated;
4108 }
4109 
4110 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
4111 {
4112 	struct list_head *head;
4113 	struct btrfs_device *dev;
4114 	struct btrfs_super_block *sb;
4115 	struct btrfs_dev_item *dev_item;
4116 	int ret;
4117 	int do_barriers;
4118 	int max_errors;
4119 	int total_errors = 0;
4120 	u64 flags;
4121 
4122 	do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
4123 
4124 	/*
4125 	 * max_mirrors == 0 indicates we're from commit_transaction,
4126 	 * not from fsync where the tree roots in fs_info have not
4127 	 * been consistent on disk.
4128 	 */
4129 	if (max_mirrors == 0)
4130 		backup_super_roots(fs_info);
4131 
4132 	sb = fs_info->super_for_commit;
4133 	dev_item = &sb->dev_item;
4134 
4135 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
4136 	head = &fs_info->fs_devices->devices;
4137 	max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
4138 
4139 	if (do_barriers) {
4140 		ret = barrier_all_devices(fs_info);
4141 		if (ret) {
4142 			mutex_unlock(
4143 				&fs_info->fs_devices->device_list_mutex);
4144 			btrfs_handle_fs_error(fs_info, ret,
4145 					      "errors while submitting device barriers.");
4146 			return ret;
4147 		}
4148 	}
4149 
4150 	list_for_each_entry(dev, head, dev_list) {
4151 		if (!dev->bdev) {
4152 			total_errors++;
4153 			continue;
4154 		}
4155 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4156 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4157 			continue;
4158 
4159 		btrfs_set_stack_device_generation(dev_item, 0);
4160 		btrfs_set_stack_device_type(dev_item, dev->type);
4161 		btrfs_set_stack_device_id(dev_item, dev->devid);
4162 		btrfs_set_stack_device_total_bytes(dev_item,
4163 						   dev->commit_total_bytes);
4164 		btrfs_set_stack_device_bytes_used(dev_item,
4165 						  dev->commit_bytes_used);
4166 		btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4167 		btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4168 		btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4169 		memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4170 		memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4171 		       BTRFS_FSID_SIZE);
4172 
4173 		flags = btrfs_super_flags(sb);
4174 		btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4175 
4176 		ret = btrfs_validate_write_super(fs_info, sb);
4177 		if (ret < 0) {
4178 			mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4179 			btrfs_handle_fs_error(fs_info, -EUCLEAN,
4180 				"unexpected superblock corruption detected");
4181 			return -EUCLEAN;
4182 		}
4183 
4184 		ret = write_dev_supers(dev, sb, max_mirrors);
4185 		if (ret)
4186 			total_errors++;
4187 	}
4188 	if (total_errors > max_errors) {
4189 		btrfs_err(fs_info, "%d errors while writing supers",
4190 			  total_errors);
4191 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4192 
4193 		/* FUA is masked off if unsupported and can't be the reason */
4194 		btrfs_handle_fs_error(fs_info, -EIO,
4195 				      "%d errors while writing supers",
4196 				      total_errors);
4197 		return -EIO;
4198 	}
4199 
4200 	total_errors = 0;
4201 	list_for_each_entry(dev, head, dev_list) {
4202 		if (!dev->bdev)
4203 			continue;
4204 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4205 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4206 			continue;
4207 
4208 		ret = wait_dev_supers(dev, max_mirrors);
4209 		if (ret)
4210 			total_errors++;
4211 	}
4212 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4213 	if (total_errors > max_errors) {
4214 		btrfs_handle_fs_error(fs_info, -EIO,
4215 				      "%d errors while writing supers",
4216 				      total_errors);
4217 		return -EIO;
4218 	}
4219 	return 0;
4220 }
4221 
4222 /* Drop a fs root from the radix tree and free it. */
4223 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4224 				  struct btrfs_root *root)
4225 {
4226 	bool drop_ref = false;
4227 
4228 	spin_lock(&fs_info->fs_roots_radix_lock);
4229 	radix_tree_delete(&fs_info->fs_roots_radix,
4230 			  (unsigned long)root->root_key.objectid);
4231 	if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4232 		drop_ref = true;
4233 	spin_unlock(&fs_info->fs_roots_radix_lock);
4234 
4235 	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
4236 		ASSERT(root->log_root == NULL);
4237 		if (root->reloc_root) {
4238 			btrfs_put_root(root->reloc_root);
4239 			root->reloc_root = NULL;
4240 		}
4241 	}
4242 
4243 	if (drop_ref)
4244 		btrfs_put_root(root);
4245 }
4246 
4247 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
4248 {
4249 	u64 root_objectid = 0;
4250 	struct btrfs_root *gang[8];
4251 	int i = 0;
4252 	int err = 0;
4253 	unsigned int ret = 0;
4254 
4255 	while (1) {
4256 		spin_lock(&fs_info->fs_roots_radix_lock);
4257 		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4258 					     (void **)gang, root_objectid,
4259 					     ARRAY_SIZE(gang));
4260 		if (!ret) {
4261 			spin_unlock(&fs_info->fs_roots_radix_lock);
4262 			break;
4263 		}
4264 		root_objectid = gang[ret - 1]->root_key.objectid + 1;
4265 
4266 		for (i = 0; i < ret; i++) {
4267 			/* Avoid to grab roots in dead_roots */
4268 			if (btrfs_root_refs(&gang[i]->root_item) == 0) {
4269 				gang[i] = NULL;
4270 				continue;
4271 			}
4272 			/* grab all the search result for later use */
4273 			gang[i] = btrfs_grab_root(gang[i]);
4274 		}
4275 		spin_unlock(&fs_info->fs_roots_radix_lock);
4276 
4277 		for (i = 0; i < ret; i++) {
4278 			if (!gang[i])
4279 				continue;
4280 			root_objectid = gang[i]->root_key.objectid;
4281 			err = btrfs_orphan_cleanup(gang[i]);
4282 			if (err)
4283 				break;
4284 			btrfs_put_root(gang[i]);
4285 		}
4286 		root_objectid++;
4287 	}
4288 
4289 	/* release the uncleaned roots due to error */
4290 	for (; i < ret; i++) {
4291 		if (gang[i])
4292 			btrfs_put_root(gang[i]);
4293 	}
4294 	return err;
4295 }
4296 
4297 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4298 {
4299 	struct btrfs_root *root = fs_info->tree_root;
4300 	struct btrfs_trans_handle *trans;
4301 
4302 	mutex_lock(&fs_info->cleaner_mutex);
4303 	btrfs_run_delayed_iputs(fs_info);
4304 	mutex_unlock(&fs_info->cleaner_mutex);
4305 	wake_up_process(fs_info->cleaner_kthread);
4306 
4307 	/* wait until ongoing cleanup work done */
4308 	down_write(&fs_info->cleanup_work_sem);
4309 	up_write(&fs_info->cleanup_work_sem);
4310 
4311 	trans = btrfs_join_transaction(root);
4312 	if (IS_ERR(trans))
4313 		return PTR_ERR(trans);
4314 	return btrfs_commit_transaction(trans);
4315 }
4316 
4317 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4318 {
4319 	int ret;
4320 
4321 	set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4322 	/*
4323 	 * We don't want the cleaner to start new transactions, add more delayed
4324 	 * iputs, etc. while we're closing. We can't use kthread_stop() yet
4325 	 * because that frees the task_struct, and the transaction kthread might
4326 	 * still try to wake up the cleaner.
4327 	 */
4328 	kthread_park(fs_info->cleaner_kthread);
4329 
4330 	/* wait for the qgroup rescan worker to stop */
4331 	btrfs_qgroup_wait_for_completion(fs_info, false);
4332 
4333 	/* wait for the uuid_scan task to finish */
4334 	down(&fs_info->uuid_tree_rescan_sem);
4335 	/* avoid complains from lockdep et al., set sem back to initial state */
4336 	up(&fs_info->uuid_tree_rescan_sem);
4337 
4338 	/* pause restriper - we want to resume on mount */
4339 	btrfs_pause_balance(fs_info);
4340 
4341 	btrfs_dev_replace_suspend_for_unmount(fs_info);
4342 
4343 	btrfs_scrub_cancel(fs_info);
4344 
4345 	/* wait for any defraggers to finish */
4346 	wait_event(fs_info->transaction_wait,
4347 		   (atomic_read(&fs_info->defrag_running) == 0));
4348 
4349 	/* clear out the rbtree of defraggable inodes */
4350 	btrfs_cleanup_defrag_inodes(fs_info);
4351 
4352 	cancel_work_sync(&fs_info->async_reclaim_work);
4353 	cancel_work_sync(&fs_info->async_data_reclaim_work);
4354 	cancel_work_sync(&fs_info->preempt_reclaim_work);
4355 
4356 	cancel_work_sync(&fs_info->reclaim_bgs_work);
4357 
4358 	/* Cancel or finish ongoing discard work */
4359 	btrfs_discard_cleanup(fs_info);
4360 
4361 	if (!sb_rdonly(fs_info->sb)) {
4362 		/*
4363 		 * The cleaner kthread is stopped, so do one final pass over
4364 		 * unused block groups.
4365 		 */
4366 		btrfs_delete_unused_bgs(fs_info);
4367 
4368 		/*
4369 		 * There might be existing delayed inode workers still running
4370 		 * and holding an empty delayed inode item. We must wait for
4371 		 * them to complete first because they can create a transaction.
4372 		 * This happens when someone calls btrfs_balance_delayed_items()
4373 		 * and then a transaction commit runs the same delayed nodes
4374 		 * before any delayed worker has done something with the nodes.
4375 		 * We must wait for any worker here and not at transaction
4376 		 * commit time since that could cause a deadlock.
4377 		 * This is a very rare case.
4378 		 */
4379 		btrfs_flush_workqueue(fs_info->delayed_workers);
4380 
4381 		ret = btrfs_commit_super(fs_info);
4382 		if (ret)
4383 			btrfs_err(fs_info, "commit super ret %d", ret);
4384 	}
4385 
4386 	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state) ||
4387 	    test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state))
4388 		btrfs_error_commit_super(fs_info);
4389 
4390 	kthread_stop(fs_info->transaction_kthread);
4391 	kthread_stop(fs_info->cleaner_kthread);
4392 
4393 	ASSERT(list_empty(&fs_info->delayed_iputs));
4394 	set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4395 
4396 	if (btrfs_check_quota_leak(fs_info)) {
4397 		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4398 		btrfs_err(fs_info, "qgroup reserved space leaked");
4399 	}
4400 
4401 	btrfs_free_qgroup_config(fs_info);
4402 	ASSERT(list_empty(&fs_info->delalloc_roots));
4403 
4404 	if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4405 		btrfs_info(fs_info, "at unmount delalloc count %lld",
4406 		       percpu_counter_sum(&fs_info->delalloc_bytes));
4407 	}
4408 
4409 	if (percpu_counter_sum(&fs_info->ordered_bytes))
4410 		btrfs_info(fs_info, "at unmount dio bytes count %lld",
4411 			   percpu_counter_sum(&fs_info->ordered_bytes));
4412 
4413 	btrfs_sysfs_remove_mounted(fs_info);
4414 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4415 
4416 	btrfs_put_block_group_cache(fs_info);
4417 
4418 	/*
4419 	 * we must make sure there is not any read request to
4420 	 * submit after we stopping all workers.
4421 	 */
4422 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4423 	btrfs_stop_all_workers(fs_info);
4424 
4425 	/* We shouldn't have any transaction open at this point */
4426 	ASSERT(list_empty(&fs_info->trans_list));
4427 
4428 	clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4429 	free_root_pointers(fs_info, true);
4430 	btrfs_free_fs_roots(fs_info);
4431 
4432 	/*
4433 	 * We must free the block groups after dropping the fs_roots as we could
4434 	 * have had an IO error and have left over tree log blocks that aren't
4435 	 * cleaned up until the fs roots are freed.  This makes the block group
4436 	 * accounting appear to be wrong because there's pending reserved bytes,
4437 	 * so make sure we do the block group cleanup afterwards.
4438 	 */
4439 	btrfs_free_block_groups(fs_info);
4440 
4441 	iput(fs_info->btree_inode);
4442 
4443 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4444 	if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
4445 		btrfsic_unmount(fs_info->fs_devices);
4446 #endif
4447 
4448 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
4449 	btrfs_close_devices(fs_info->fs_devices);
4450 }
4451 
4452 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
4453 			  int atomic)
4454 {
4455 	int ret;
4456 	struct inode *btree_inode = buf->pages[0]->mapping->host;
4457 
4458 	ret = extent_buffer_uptodate(buf);
4459 	if (!ret)
4460 		return ret;
4461 
4462 	ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
4463 				    parent_transid, atomic);
4464 	if (ret == -EAGAIN)
4465 		return ret;
4466 	return !ret;
4467 }
4468 
4469 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
4470 {
4471 	struct btrfs_fs_info *fs_info = buf->fs_info;
4472 	u64 transid = btrfs_header_generation(buf);
4473 	int was_dirty;
4474 
4475 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4476 	/*
4477 	 * This is a fast path so only do this check if we have sanity tests
4478 	 * enabled.  Normal people shouldn't be using unmapped buffers as dirty
4479 	 * outside of the sanity tests.
4480 	 */
4481 	if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4482 		return;
4483 #endif
4484 	btrfs_assert_tree_locked(buf);
4485 	if (transid != fs_info->generation)
4486 		WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, found %llu running %llu\n",
4487 			buf->start, transid, fs_info->generation);
4488 	was_dirty = set_extent_buffer_dirty(buf);
4489 	if (!was_dirty)
4490 		percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
4491 					 buf->len,
4492 					 fs_info->dirty_metadata_batch);
4493 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4494 	/*
4495 	 * Since btrfs_mark_buffer_dirty() can be called with item pointer set
4496 	 * but item data not updated.
4497 	 * So here we should only check item pointers, not item data.
4498 	 */
4499 	if (btrfs_header_level(buf) == 0 &&
4500 	    btrfs_check_leaf_relaxed(buf)) {
4501 		btrfs_print_leaf(buf);
4502 		ASSERT(0);
4503 	}
4504 #endif
4505 }
4506 
4507 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4508 					int flush_delayed)
4509 {
4510 	/*
4511 	 * looks as though older kernels can get into trouble with
4512 	 * this code, they end up stuck in balance_dirty_pages forever
4513 	 */
4514 	int ret;
4515 
4516 	if (current->flags & PF_MEMALLOC)
4517 		return;
4518 
4519 	if (flush_delayed)
4520 		btrfs_balance_delayed_items(fs_info);
4521 
4522 	ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4523 				     BTRFS_DIRTY_METADATA_THRESH,
4524 				     fs_info->dirty_metadata_batch);
4525 	if (ret > 0) {
4526 		balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4527 	}
4528 }
4529 
4530 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4531 {
4532 	__btrfs_btree_balance_dirty(fs_info, 1);
4533 }
4534 
4535 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4536 {
4537 	__btrfs_btree_balance_dirty(fs_info, 0);
4538 }
4539 
4540 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
4541 		      struct btrfs_key *first_key)
4542 {
4543 	return btree_read_extent_buffer_pages(buf, parent_transid,
4544 					      level, first_key);
4545 }
4546 
4547 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4548 {
4549 	/* cleanup FS via transaction */
4550 	btrfs_cleanup_transaction(fs_info);
4551 
4552 	mutex_lock(&fs_info->cleaner_mutex);
4553 	btrfs_run_delayed_iputs(fs_info);
4554 	mutex_unlock(&fs_info->cleaner_mutex);
4555 
4556 	down_write(&fs_info->cleanup_work_sem);
4557 	up_write(&fs_info->cleanup_work_sem);
4558 }
4559 
4560 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4561 {
4562 	struct btrfs_root *gang[8];
4563 	u64 root_objectid = 0;
4564 	int ret;
4565 
4566 	spin_lock(&fs_info->fs_roots_radix_lock);
4567 	while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4568 					     (void **)gang, root_objectid,
4569 					     ARRAY_SIZE(gang))) != 0) {
4570 		int i;
4571 
4572 		for (i = 0; i < ret; i++)
4573 			gang[i] = btrfs_grab_root(gang[i]);
4574 		spin_unlock(&fs_info->fs_roots_radix_lock);
4575 
4576 		for (i = 0; i < ret; i++) {
4577 			if (!gang[i])
4578 				continue;
4579 			root_objectid = gang[i]->root_key.objectid;
4580 			btrfs_free_log(NULL, gang[i]);
4581 			btrfs_put_root(gang[i]);
4582 		}
4583 		root_objectid++;
4584 		spin_lock(&fs_info->fs_roots_radix_lock);
4585 	}
4586 	spin_unlock(&fs_info->fs_roots_radix_lock);
4587 	btrfs_free_log_root_tree(NULL, fs_info);
4588 }
4589 
4590 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4591 {
4592 	struct btrfs_ordered_extent *ordered;
4593 
4594 	spin_lock(&root->ordered_extent_lock);
4595 	/*
4596 	 * This will just short circuit the ordered completion stuff which will
4597 	 * make sure the ordered extent gets properly cleaned up.
4598 	 */
4599 	list_for_each_entry(ordered, &root->ordered_extents,
4600 			    root_extent_list)
4601 		set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4602 	spin_unlock(&root->ordered_extent_lock);
4603 }
4604 
4605 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4606 {
4607 	struct btrfs_root *root;
4608 	struct list_head splice;
4609 
4610 	INIT_LIST_HEAD(&splice);
4611 
4612 	spin_lock(&fs_info->ordered_root_lock);
4613 	list_splice_init(&fs_info->ordered_roots, &splice);
4614 	while (!list_empty(&splice)) {
4615 		root = list_first_entry(&splice, struct btrfs_root,
4616 					ordered_root);
4617 		list_move_tail(&root->ordered_root,
4618 			       &fs_info->ordered_roots);
4619 
4620 		spin_unlock(&fs_info->ordered_root_lock);
4621 		btrfs_destroy_ordered_extents(root);
4622 
4623 		cond_resched();
4624 		spin_lock(&fs_info->ordered_root_lock);
4625 	}
4626 	spin_unlock(&fs_info->ordered_root_lock);
4627 
4628 	/*
4629 	 * We need this here because if we've been flipped read-only we won't
4630 	 * get sync() from the umount, so we need to make sure any ordered
4631 	 * extents that haven't had their dirty pages IO start writeout yet
4632 	 * actually get run and error out properly.
4633 	 */
4634 	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
4635 }
4636 
4637 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4638 				      struct btrfs_fs_info *fs_info)
4639 {
4640 	struct rb_node *node;
4641 	struct btrfs_delayed_ref_root *delayed_refs;
4642 	struct btrfs_delayed_ref_node *ref;
4643 	int ret = 0;
4644 
4645 	delayed_refs = &trans->delayed_refs;
4646 
4647 	spin_lock(&delayed_refs->lock);
4648 	if (atomic_read(&delayed_refs->num_entries) == 0) {
4649 		spin_unlock(&delayed_refs->lock);
4650 		btrfs_debug(fs_info, "delayed_refs has NO entry");
4651 		return ret;
4652 	}
4653 
4654 	while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
4655 		struct btrfs_delayed_ref_head *head;
4656 		struct rb_node *n;
4657 		bool pin_bytes = false;
4658 
4659 		head = rb_entry(node, struct btrfs_delayed_ref_head,
4660 				href_node);
4661 		if (btrfs_delayed_ref_lock(delayed_refs, head))
4662 			continue;
4663 
4664 		spin_lock(&head->lock);
4665 		while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
4666 			ref = rb_entry(n, struct btrfs_delayed_ref_node,
4667 				       ref_node);
4668 			ref->in_tree = 0;
4669 			rb_erase_cached(&ref->ref_node, &head->ref_tree);
4670 			RB_CLEAR_NODE(&ref->ref_node);
4671 			if (!list_empty(&ref->add_list))
4672 				list_del(&ref->add_list);
4673 			atomic_dec(&delayed_refs->num_entries);
4674 			btrfs_put_delayed_ref(ref);
4675 		}
4676 		if (head->must_insert_reserved)
4677 			pin_bytes = true;
4678 		btrfs_free_delayed_extent_op(head->extent_op);
4679 		btrfs_delete_ref_head(delayed_refs, head);
4680 		spin_unlock(&head->lock);
4681 		spin_unlock(&delayed_refs->lock);
4682 		mutex_unlock(&head->mutex);
4683 
4684 		if (pin_bytes) {
4685 			struct btrfs_block_group *cache;
4686 
4687 			cache = btrfs_lookup_block_group(fs_info, head->bytenr);
4688 			BUG_ON(!cache);
4689 
4690 			spin_lock(&cache->space_info->lock);
4691 			spin_lock(&cache->lock);
4692 			cache->pinned += head->num_bytes;
4693 			btrfs_space_info_update_bytes_pinned(fs_info,
4694 				cache->space_info, head->num_bytes);
4695 			cache->reserved -= head->num_bytes;
4696 			cache->space_info->bytes_reserved -= head->num_bytes;
4697 			spin_unlock(&cache->lock);
4698 			spin_unlock(&cache->space_info->lock);
4699 			percpu_counter_add_batch(
4700 				&cache->space_info->total_bytes_pinned,
4701 				head->num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH);
4702 
4703 			btrfs_put_block_group(cache);
4704 
4705 			btrfs_error_unpin_extent_range(fs_info, head->bytenr,
4706 				head->bytenr + head->num_bytes - 1);
4707 		}
4708 		btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
4709 		btrfs_put_delayed_ref_head(head);
4710 		cond_resched();
4711 		spin_lock(&delayed_refs->lock);
4712 	}
4713 	btrfs_qgroup_destroy_extent_records(trans);
4714 
4715 	spin_unlock(&delayed_refs->lock);
4716 
4717 	return ret;
4718 }
4719 
4720 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4721 {
4722 	struct btrfs_inode *btrfs_inode;
4723 	struct list_head splice;
4724 
4725 	INIT_LIST_HEAD(&splice);
4726 
4727 	spin_lock(&root->delalloc_lock);
4728 	list_splice_init(&root->delalloc_inodes, &splice);
4729 
4730 	while (!list_empty(&splice)) {
4731 		struct inode *inode = NULL;
4732 		btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4733 					       delalloc_inodes);
4734 		__btrfs_del_delalloc_inode(root, btrfs_inode);
4735 		spin_unlock(&root->delalloc_lock);
4736 
4737 		/*
4738 		 * Make sure we get a live inode and that it'll not disappear
4739 		 * meanwhile.
4740 		 */
4741 		inode = igrab(&btrfs_inode->vfs_inode);
4742 		if (inode) {
4743 			invalidate_inode_pages2(inode->i_mapping);
4744 			iput(inode);
4745 		}
4746 		spin_lock(&root->delalloc_lock);
4747 	}
4748 	spin_unlock(&root->delalloc_lock);
4749 }
4750 
4751 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4752 {
4753 	struct btrfs_root *root;
4754 	struct list_head splice;
4755 
4756 	INIT_LIST_HEAD(&splice);
4757 
4758 	spin_lock(&fs_info->delalloc_root_lock);
4759 	list_splice_init(&fs_info->delalloc_roots, &splice);
4760 	while (!list_empty(&splice)) {
4761 		root = list_first_entry(&splice, struct btrfs_root,
4762 					 delalloc_root);
4763 		root = btrfs_grab_root(root);
4764 		BUG_ON(!root);
4765 		spin_unlock(&fs_info->delalloc_root_lock);
4766 
4767 		btrfs_destroy_delalloc_inodes(root);
4768 		btrfs_put_root(root);
4769 
4770 		spin_lock(&fs_info->delalloc_root_lock);
4771 	}
4772 	spin_unlock(&fs_info->delalloc_root_lock);
4773 }
4774 
4775 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
4776 					struct extent_io_tree *dirty_pages,
4777 					int mark)
4778 {
4779 	int ret;
4780 	struct extent_buffer *eb;
4781 	u64 start = 0;
4782 	u64 end;
4783 
4784 	while (1) {
4785 		ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4786 					    mark, NULL);
4787 		if (ret)
4788 			break;
4789 
4790 		clear_extent_bits(dirty_pages, start, end, mark);
4791 		while (start <= end) {
4792 			eb = find_extent_buffer(fs_info, start);
4793 			start += fs_info->nodesize;
4794 			if (!eb)
4795 				continue;
4796 			wait_on_extent_buffer_writeback(eb);
4797 
4798 			if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4799 					       &eb->bflags))
4800 				clear_extent_buffer_dirty(eb);
4801 			free_extent_buffer_stale(eb);
4802 		}
4803 	}
4804 
4805 	return ret;
4806 }
4807 
4808 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
4809 				       struct extent_io_tree *unpin)
4810 {
4811 	u64 start;
4812 	u64 end;
4813 	int ret;
4814 
4815 	while (1) {
4816 		struct extent_state *cached_state = NULL;
4817 
4818 		/*
4819 		 * The btrfs_finish_extent_commit() may get the same range as
4820 		 * ours between find_first_extent_bit and clear_extent_dirty.
4821 		 * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
4822 		 * the same extent range.
4823 		 */
4824 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
4825 		ret = find_first_extent_bit(unpin, 0, &start, &end,
4826 					    EXTENT_DIRTY, &cached_state);
4827 		if (ret) {
4828 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4829 			break;
4830 		}
4831 
4832 		clear_extent_dirty(unpin, start, end, &cached_state);
4833 		free_extent_state(cached_state);
4834 		btrfs_error_unpin_extent_range(fs_info, start, end);
4835 		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4836 		cond_resched();
4837 	}
4838 
4839 	return 0;
4840 }
4841 
4842 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
4843 {
4844 	struct inode *inode;
4845 
4846 	inode = cache->io_ctl.inode;
4847 	if (inode) {
4848 		invalidate_inode_pages2(inode->i_mapping);
4849 		BTRFS_I(inode)->generation = 0;
4850 		cache->io_ctl.inode = NULL;
4851 		iput(inode);
4852 	}
4853 	ASSERT(cache->io_ctl.pages == NULL);
4854 	btrfs_put_block_group(cache);
4855 }
4856 
4857 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
4858 			     struct btrfs_fs_info *fs_info)
4859 {
4860 	struct btrfs_block_group *cache;
4861 
4862 	spin_lock(&cur_trans->dirty_bgs_lock);
4863 	while (!list_empty(&cur_trans->dirty_bgs)) {
4864 		cache = list_first_entry(&cur_trans->dirty_bgs,
4865 					 struct btrfs_block_group,
4866 					 dirty_list);
4867 
4868 		if (!list_empty(&cache->io_list)) {
4869 			spin_unlock(&cur_trans->dirty_bgs_lock);
4870 			list_del_init(&cache->io_list);
4871 			btrfs_cleanup_bg_io(cache);
4872 			spin_lock(&cur_trans->dirty_bgs_lock);
4873 		}
4874 
4875 		list_del_init(&cache->dirty_list);
4876 		spin_lock(&cache->lock);
4877 		cache->disk_cache_state = BTRFS_DC_ERROR;
4878 		spin_unlock(&cache->lock);
4879 
4880 		spin_unlock(&cur_trans->dirty_bgs_lock);
4881 		btrfs_put_block_group(cache);
4882 		btrfs_delayed_refs_rsv_release(fs_info, 1);
4883 		spin_lock(&cur_trans->dirty_bgs_lock);
4884 	}
4885 	spin_unlock(&cur_trans->dirty_bgs_lock);
4886 
4887 	/*
4888 	 * Refer to the definition of io_bgs member for details why it's safe
4889 	 * to use it without any locking
4890 	 */
4891 	while (!list_empty(&cur_trans->io_bgs)) {
4892 		cache = list_first_entry(&cur_trans->io_bgs,
4893 					 struct btrfs_block_group,
4894 					 io_list);
4895 
4896 		list_del_init(&cache->io_list);
4897 		spin_lock(&cache->lock);
4898 		cache->disk_cache_state = BTRFS_DC_ERROR;
4899 		spin_unlock(&cache->lock);
4900 		btrfs_cleanup_bg_io(cache);
4901 	}
4902 }
4903 
4904 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4905 				   struct btrfs_fs_info *fs_info)
4906 {
4907 	struct btrfs_device *dev, *tmp;
4908 
4909 	btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
4910 	ASSERT(list_empty(&cur_trans->dirty_bgs));
4911 	ASSERT(list_empty(&cur_trans->io_bgs));
4912 
4913 	list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
4914 				 post_commit_list) {
4915 		list_del_init(&dev->post_commit_list);
4916 	}
4917 
4918 	btrfs_destroy_delayed_refs(cur_trans, fs_info);
4919 
4920 	cur_trans->state = TRANS_STATE_COMMIT_START;
4921 	wake_up(&fs_info->transaction_blocked_wait);
4922 
4923 	cur_trans->state = TRANS_STATE_UNBLOCKED;
4924 	wake_up(&fs_info->transaction_wait);
4925 
4926 	btrfs_destroy_delayed_inodes(fs_info);
4927 
4928 	btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
4929 				     EXTENT_DIRTY);
4930 	btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
4931 
4932 	btrfs_free_redirty_list(cur_trans);
4933 
4934 	cur_trans->state =TRANS_STATE_COMPLETED;
4935 	wake_up(&cur_trans->commit_wait);
4936 }
4937 
4938 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
4939 {
4940 	struct btrfs_transaction *t;
4941 
4942 	mutex_lock(&fs_info->transaction_kthread_mutex);
4943 
4944 	spin_lock(&fs_info->trans_lock);
4945 	while (!list_empty(&fs_info->trans_list)) {
4946 		t = list_first_entry(&fs_info->trans_list,
4947 				     struct btrfs_transaction, list);
4948 		if (t->state >= TRANS_STATE_COMMIT_START) {
4949 			refcount_inc(&t->use_count);
4950 			spin_unlock(&fs_info->trans_lock);
4951 			btrfs_wait_for_commit(fs_info, t->transid);
4952 			btrfs_put_transaction(t);
4953 			spin_lock(&fs_info->trans_lock);
4954 			continue;
4955 		}
4956 		if (t == fs_info->running_transaction) {
4957 			t->state = TRANS_STATE_COMMIT_DOING;
4958 			spin_unlock(&fs_info->trans_lock);
4959 			/*
4960 			 * We wait for 0 num_writers since we don't hold a trans
4961 			 * handle open currently for this transaction.
4962 			 */
4963 			wait_event(t->writer_wait,
4964 				   atomic_read(&t->num_writers) == 0);
4965 		} else {
4966 			spin_unlock(&fs_info->trans_lock);
4967 		}
4968 		btrfs_cleanup_one_transaction(t, fs_info);
4969 
4970 		spin_lock(&fs_info->trans_lock);
4971 		if (t == fs_info->running_transaction)
4972 			fs_info->running_transaction = NULL;
4973 		list_del_init(&t->list);
4974 		spin_unlock(&fs_info->trans_lock);
4975 
4976 		btrfs_put_transaction(t);
4977 		trace_btrfs_transaction_commit(fs_info->tree_root);
4978 		spin_lock(&fs_info->trans_lock);
4979 	}
4980 	spin_unlock(&fs_info->trans_lock);
4981 	btrfs_destroy_all_ordered_extents(fs_info);
4982 	btrfs_destroy_delayed_inodes(fs_info);
4983 	btrfs_assert_delayed_root_empty(fs_info);
4984 	btrfs_destroy_all_delalloc_inodes(fs_info);
4985 	btrfs_drop_all_logs(fs_info);
4986 	mutex_unlock(&fs_info->transaction_kthread_mutex);
4987 
4988 	return 0;
4989 }
4990 
4991 int btrfs_init_root_free_objectid(struct btrfs_root *root)
4992 {
4993 	struct btrfs_path *path;
4994 	int ret;
4995 	struct extent_buffer *l;
4996 	struct btrfs_key search_key;
4997 	struct btrfs_key found_key;
4998 	int slot;
4999 
5000 	path = btrfs_alloc_path();
5001 	if (!path)
5002 		return -ENOMEM;
5003 
5004 	search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
5005 	search_key.type = -1;
5006 	search_key.offset = (u64)-1;
5007 	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
5008 	if (ret < 0)
5009 		goto error;
5010 	BUG_ON(ret == 0); /* Corruption */
5011 	if (path->slots[0] > 0) {
5012 		slot = path->slots[0] - 1;
5013 		l = path->nodes[0];
5014 		btrfs_item_key_to_cpu(l, &found_key, slot);
5015 		root->free_objectid = max_t(u64, found_key.objectid + 1,
5016 					    BTRFS_FIRST_FREE_OBJECTID);
5017 	} else {
5018 		root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
5019 	}
5020 	ret = 0;
5021 error:
5022 	btrfs_free_path(path);
5023 	return ret;
5024 }
5025 
5026 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
5027 {
5028 	int ret;
5029 	mutex_lock(&root->objectid_mutex);
5030 
5031 	if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
5032 		btrfs_warn(root->fs_info,
5033 			   "the objectid of root %llu reaches its highest value",
5034 			   root->root_key.objectid);
5035 		ret = -ENOSPC;
5036 		goto out;
5037 	}
5038 
5039 	*objectid = root->free_objectid++;
5040 	ret = 0;
5041 out:
5042 	mutex_unlock(&root->objectid_mutex);
5043 	return ret;
5044 }
5045