xref: /linux/fs/btrfs/disk-io.c (revision 5a087a6b17eeb64893b81d08d38e6f6300419ee5)
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 <linux/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 "bio.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 "dev-replace.h"
33 #include "raid56.h"
34 #include "sysfs.h"
35 #include "qgroup.h"
36 #include "compression.h"
37 #include "tree-checker.h"
38 #include "ref-verify.h"
39 #include "block-group.h"
40 #include "discard.h"
41 #include "space-info.h"
42 #include "zoned.h"
43 #include "subpage.h"
44 #include "fs.h"
45 #include "accessors.h"
46 #include "extent-tree.h"
47 #include "root-tree.h"
48 #include "defrag.h"
49 #include "uuid-tree.h"
50 #include "relocation.h"
51 #include "scrub.h"
52 #include "super.h"
53 
54 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN |\
55 				 BTRFS_HEADER_FLAG_RELOC |\
56 				 BTRFS_SUPER_FLAG_ERROR |\
57 				 BTRFS_SUPER_FLAG_SEEDING |\
58 				 BTRFS_SUPER_FLAG_METADUMP |\
59 				 BTRFS_SUPER_FLAG_METADUMP_V2)
60 
61 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
62 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
63 
btrfs_free_csum_hash(struct btrfs_fs_info * fs_info)64 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
65 {
66 	if (fs_info->csum_shash)
67 		crypto_free_shash(fs_info->csum_shash);
68 }
69 
70 /*
71  * Compute the csum of a btree block and store the result to provided buffer.
72  */
csum_tree_block(struct extent_buffer * buf,u8 * result)73 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
74 {
75 	struct btrfs_fs_info *fs_info = buf->fs_info;
76 	int num_pages;
77 	u32 first_page_part;
78 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
79 	char *kaddr;
80 	int i;
81 
82 	shash->tfm = fs_info->csum_shash;
83 	crypto_shash_init(shash);
84 
85 	if (buf->addr) {
86 		/* Pages are contiguous, handle them as a big one. */
87 		kaddr = buf->addr;
88 		first_page_part = fs_info->nodesize;
89 		num_pages = 1;
90 	} else {
91 		kaddr = folio_address(buf->folios[0]);
92 		first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
93 		num_pages = num_extent_pages(buf);
94 	}
95 
96 	crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
97 			    first_page_part - BTRFS_CSUM_SIZE);
98 
99 	/*
100 	 * Multiple single-page folios case would reach here.
101 	 *
102 	 * nodesize <= PAGE_SIZE and large folio all handled by above
103 	 * crypto_shash_update() already.
104 	 */
105 	for (i = 1; i < num_pages && INLINE_EXTENT_BUFFER_PAGES > 1; i++) {
106 		kaddr = folio_address(buf->folios[i]);
107 		crypto_shash_update(shash, kaddr, PAGE_SIZE);
108 	}
109 	memset(result, 0, BTRFS_CSUM_SIZE);
110 	crypto_shash_final(shash, result);
111 }
112 
113 /*
114  * we can't consider a given block up to date unless the transid of the
115  * block matches the transid in the parent node's pointer.  This is how we
116  * detect blocks that either didn't get written at all or got written
117  * in the wrong place.
118  */
btrfs_buffer_uptodate(struct extent_buffer * eb,u64 parent_transid,int atomic)119 int btrfs_buffer_uptodate(struct extent_buffer *eb, u64 parent_transid, int atomic)
120 {
121 	if (!extent_buffer_uptodate(eb))
122 		return 0;
123 
124 	if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
125 		return 1;
126 
127 	if (atomic)
128 		return -EAGAIN;
129 
130 	if (!extent_buffer_uptodate(eb) ||
131 	    btrfs_header_generation(eb) != parent_transid) {
132 		btrfs_err_rl(eb->fs_info,
133 "parent transid verify failed on logical %llu mirror %u wanted %llu found %llu",
134 			eb->start, eb->read_mirror,
135 			parent_transid, btrfs_header_generation(eb));
136 		clear_extent_buffer_uptodate(eb);
137 		return 0;
138 	}
139 	return 1;
140 }
141 
btrfs_supported_super_csum(u16 csum_type)142 static bool btrfs_supported_super_csum(u16 csum_type)
143 {
144 	switch (csum_type) {
145 	case BTRFS_CSUM_TYPE_CRC32:
146 	case BTRFS_CSUM_TYPE_XXHASH:
147 	case BTRFS_CSUM_TYPE_SHA256:
148 	case BTRFS_CSUM_TYPE_BLAKE2:
149 		return true;
150 	default:
151 		return false;
152 	}
153 }
154 
155 /*
156  * Return 0 if the superblock checksum type matches the checksum value of that
157  * algorithm. Pass the raw disk superblock data.
158  */
btrfs_check_super_csum(struct btrfs_fs_info * fs_info,const struct btrfs_super_block * disk_sb)159 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
160 			   const struct btrfs_super_block *disk_sb)
161 {
162 	char result[BTRFS_CSUM_SIZE];
163 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
164 
165 	shash->tfm = fs_info->csum_shash;
166 
167 	/*
168 	 * The super_block structure does not span the whole
169 	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
170 	 * filled with zeros and is included in the checksum.
171 	 */
172 	crypto_shash_digest(shash, (const u8 *)disk_sb + BTRFS_CSUM_SIZE,
173 			    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
174 
175 	if (memcmp(disk_sb->csum, result, fs_info->csum_size))
176 		return 1;
177 
178 	return 0;
179 }
180 
btrfs_repair_eb_io_failure(const struct extent_buffer * eb,int mirror_num)181 static int btrfs_repair_eb_io_failure(const struct extent_buffer *eb,
182 				      int mirror_num)
183 {
184 	struct btrfs_fs_info *fs_info = eb->fs_info;
185 	int num_folios = num_extent_folios(eb);
186 	int ret = 0;
187 
188 	if (sb_rdonly(fs_info->sb))
189 		return -EROFS;
190 
191 	for (int i = 0; i < num_folios; i++) {
192 		struct folio *folio = eb->folios[i];
193 		u64 start = max_t(u64, eb->start, folio_pos(folio));
194 		u64 end = min_t(u64, eb->start + eb->len,
195 				folio_pos(folio) + eb->folio_size);
196 		u32 len = end - start;
197 
198 		ret = btrfs_repair_io_failure(fs_info, 0, start, len,
199 					      start, folio, offset_in_folio(folio, start),
200 					      mirror_num);
201 		if (ret)
202 			break;
203 	}
204 
205 	return ret;
206 }
207 
208 /*
209  * helper to read a given tree block, doing retries as required when
210  * the checksums don't match and we have alternate mirrors to try.
211  *
212  * @check:		expected tree parentness check, see the comments of the
213  *			structure for details.
214  */
btrfs_read_extent_buffer(struct extent_buffer * eb,const struct btrfs_tree_parent_check * check)215 int btrfs_read_extent_buffer(struct extent_buffer *eb,
216 			     const struct btrfs_tree_parent_check *check)
217 {
218 	struct btrfs_fs_info *fs_info = eb->fs_info;
219 	int failed = 0;
220 	int ret;
221 	int num_copies = 0;
222 	int mirror_num = 0;
223 	int failed_mirror = 0;
224 
225 	ASSERT(check);
226 
227 	while (1) {
228 		clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
229 		ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num, check);
230 		if (!ret)
231 			break;
232 
233 		num_copies = btrfs_num_copies(fs_info,
234 					      eb->start, eb->len);
235 		if (num_copies == 1)
236 			break;
237 
238 		if (!failed_mirror) {
239 			failed = 1;
240 			failed_mirror = eb->read_mirror;
241 		}
242 
243 		mirror_num++;
244 		if (mirror_num == failed_mirror)
245 			mirror_num++;
246 
247 		if (mirror_num > num_copies)
248 			break;
249 	}
250 
251 	if (failed && !ret && failed_mirror)
252 		btrfs_repair_eb_io_failure(eb, failed_mirror);
253 
254 	return ret;
255 }
256 
257 /*
258  * Checksum a dirty tree block before IO.
259  */
btree_csum_one_bio(struct btrfs_bio * bbio)260 blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio)
261 {
262 	struct extent_buffer *eb = bbio->private;
263 	struct btrfs_fs_info *fs_info = eb->fs_info;
264 	u64 found_start = btrfs_header_bytenr(eb);
265 	u64 last_trans;
266 	u8 result[BTRFS_CSUM_SIZE];
267 	int ret;
268 
269 	/* Btree blocks are always contiguous on disk. */
270 	if (WARN_ON_ONCE(bbio->file_offset != eb->start))
271 		return BLK_STS_IOERR;
272 	if (WARN_ON_ONCE(bbio->bio.bi_iter.bi_size != eb->len))
273 		return BLK_STS_IOERR;
274 
275 	/*
276 	 * If an extent_buffer is marked as EXTENT_BUFFER_ZONED_ZEROOUT, don't
277 	 * checksum it but zero-out its content. This is done to preserve
278 	 * ordering of I/O without unnecessarily writing out data.
279 	 */
280 	if (test_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags)) {
281 		memzero_extent_buffer(eb, 0, eb->len);
282 		return BLK_STS_OK;
283 	}
284 
285 	if (WARN_ON_ONCE(found_start != eb->start))
286 		return BLK_STS_IOERR;
287 	if (WARN_ON(!btrfs_folio_test_uptodate(fs_info, eb->folios[0],
288 					       eb->start, eb->len)))
289 		return BLK_STS_IOERR;
290 
291 	ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
292 				    offsetof(struct btrfs_header, fsid),
293 				    BTRFS_FSID_SIZE) == 0);
294 	csum_tree_block(eb, result);
295 
296 	if (btrfs_header_level(eb))
297 		ret = btrfs_check_node(eb);
298 	else
299 		ret = btrfs_check_leaf(eb);
300 
301 	if (ret < 0)
302 		goto error;
303 
304 	/*
305 	 * Also check the generation, the eb reached here must be newer than
306 	 * last committed. Or something seriously wrong happened.
307 	 */
308 	last_trans = btrfs_get_last_trans_committed(fs_info);
309 	if (unlikely(btrfs_header_generation(eb) <= last_trans)) {
310 		ret = -EUCLEAN;
311 		btrfs_err(fs_info,
312 			"block=%llu bad generation, have %llu expect > %llu",
313 			  eb->start, btrfs_header_generation(eb), last_trans);
314 		goto error;
315 	}
316 	write_extent_buffer(eb, result, 0, fs_info->csum_size);
317 	return BLK_STS_OK;
318 
319 error:
320 	btrfs_print_tree(eb, 0);
321 	btrfs_err(fs_info, "block=%llu write time tree block corruption detected",
322 		  eb->start);
323 	/*
324 	 * Be noisy if this is an extent buffer from a log tree. We don't abort
325 	 * a transaction in case there's a bad log tree extent buffer, we just
326 	 * fallback to a transaction commit. Still we want to know when there is
327 	 * a bad log tree extent buffer, as that may signal a bug somewhere.
328 	 */
329 	WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG) ||
330 		btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID);
331 	return errno_to_blk_status(ret);
332 }
333 
check_tree_block_fsid(struct extent_buffer * eb)334 static bool check_tree_block_fsid(struct extent_buffer *eb)
335 {
336 	struct btrfs_fs_info *fs_info = eb->fs_info;
337 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
338 	u8 fsid[BTRFS_FSID_SIZE];
339 
340 	read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
341 			   BTRFS_FSID_SIZE);
342 
343 	/*
344 	 * alloc_fsid_devices() copies the fsid into fs_devices::metadata_uuid.
345 	 * This is then overwritten by metadata_uuid if it is present in the
346 	 * device_list_add(). The same true for a seed device as well. So use of
347 	 * fs_devices::metadata_uuid is appropriate here.
348 	 */
349 	if (memcmp(fsid, fs_info->fs_devices->metadata_uuid, BTRFS_FSID_SIZE) == 0)
350 		return false;
351 
352 	list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
353 		if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
354 			return false;
355 
356 	return true;
357 }
358 
359 /* Do basic extent buffer checks at read time */
btrfs_validate_extent_buffer(struct extent_buffer * eb,const struct btrfs_tree_parent_check * check)360 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
361 				 const struct btrfs_tree_parent_check *check)
362 {
363 	struct btrfs_fs_info *fs_info = eb->fs_info;
364 	u64 found_start;
365 	const u32 csum_size = fs_info->csum_size;
366 	u8 found_level;
367 	u8 result[BTRFS_CSUM_SIZE];
368 	const u8 *header_csum;
369 	int ret = 0;
370 	const bool ignore_csum = btrfs_test_opt(fs_info, IGNOREMETACSUMS);
371 
372 	ASSERT(check);
373 
374 	found_start = btrfs_header_bytenr(eb);
375 	if (found_start != eb->start) {
376 		btrfs_err_rl(fs_info,
377 			"bad tree block start, mirror %u want %llu have %llu",
378 			     eb->read_mirror, eb->start, found_start);
379 		ret = -EIO;
380 		goto out;
381 	}
382 	if (check_tree_block_fsid(eb)) {
383 		btrfs_err_rl(fs_info, "bad fsid on logical %llu mirror %u",
384 			     eb->start, eb->read_mirror);
385 		ret = -EIO;
386 		goto out;
387 	}
388 	found_level = btrfs_header_level(eb);
389 	if (found_level >= BTRFS_MAX_LEVEL) {
390 		btrfs_err(fs_info,
391 			"bad tree block level, mirror %u level %d on logical %llu",
392 			eb->read_mirror, btrfs_header_level(eb), eb->start);
393 		ret = -EIO;
394 		goto out;
395 	}
396 
397 	csum_tree_block(eb, result);
398 	header_csum = folio_address(eb->folios[0]) +
399 		get_eb_offset_in_folio(eb, offsetof(struct btrfs_header, csum));
400 
401 	if (memcmp(result, header_csum, csum_size) != 0) {
402 		btrfs_warn_rl(fs_info,
403 "checksum verify failed on logical %llu mirror %u wanted " CSUM_FMT " found " CSUM_FMT " level %d%s",
404 			      eb->start, eb->read_mirror,
405 			      CSUM_FMT_VALUE(csum_size, header_csum),
406 			      CSUM_FMT_VALUE(csum_size, result),
407 			      btrfs_header_level(eb),
408 			      ignore_csum ? ", ignored" : "");
409 		if (!ignore_csum) {
410 			ret = -EUCLEAN;
411 			goto out;
412 		}
413 	}
414 
415 	if (found_level != check->level) {
416 		btrfs_err(fs_info,
417 		"level verify failed on logical %llu mirror %u wanted %u found %u",
418 			  eb->start, eb->read_mirror, check->level, found_level);
419 		ret = -EIO;
420 		goto out;
421 	}
422 	if (unlikely(check->transid &&
423 		     btrfs_header_generation(eb) != check->transid)) {
424 		btrfs_err_rl(eb->fs_info,
425 "parent transid verify failed on logical %llu mirror %u wanted %llu found %llu",
426 				eb->start, eb->read_mirror, check->transid,
427 				btrfs_header_generation(eb));
428 		ret = -EIO;
429 		goto out;
430 	}
431 	if (check->has_first_key) {
432 		const struct btrfs_key *expect_key = &check->first_key;
433 		struct btrfs_key found_key;
434 
435 		if (found_level)
436 			btrfs_node_key_to_cpu(eb, &found_key, 0);
437 		else
438 			btrfs_item_key_to_cpu(eb, &found_key, 0);
439 		if (unlikely(btrfs_comp_cpu_keys(expect_key, &found_key))) {
440 			btrfs_err(fs_info,
441 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
442 				  eb->start, check->transid,
443 				  expect_key->objectid,
444 				  expect_key->type, expect_key->offset,
445 				  found_key.objectid, found_key.type,
446 				  found_key.offset);
447 			ret = -EUCLEAN;
448 			goto out;
449 		}
450 	}
451 	if (check->owner_root) {
452 		ret = btrfs_check_eb_owner(eb, check->owner_root);
453 		if (ret < 0)
454 			goto out;
455 	}
456 
457 	/*
458 	 * If this is a leaf block and it is corrupt, set the corrupt bit so
459 	 * that we don't try and read the other copies of this block, just
460 	 * return -EIO.
461 	 */
462 	if (found_level == 0 && btrfs_check_leaf(eb)) {
463 		set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
464 		ret = -EIO;
465 	}
466 
467 	if (found_level > 0 && btrfs_check_node(eb))
468 		ret = -EIO;
469 
470 	if (ret)
471 		btrfs_err(fs_info,
472 		"read time tree block corruption detected on logical %llu mirror %u",
473 			  eb->start, eb->read_mirror);
474 out:
475 	return ret;
476 }
477 
478 #ifdef CONFIG_MIGRATION
btree_migrate_folio(struct address_space * mapping,struct folio * dst,struct folio * src,enum migrate_mode mode)479 static int btree_migrate_folio(struct address_space *mapping,
480 		struct folio *dst, struct folio *src, enum migrate_mode mode)
481 {
482 	/*
483 	 * we can't safely write a btree page from here,
484 	 * we haven't done the locking hook
485 	 */
486 	if (folio_test_dirty(src))
487 		return -EAGAIN;
488 	/*
489 	 * Buffers may be managed in a filesystem specific way.
490 	 * We must have no buffers or drop them.
491 	 */
492 	if (folio_get_private(src) &&
493 	    !filemap_release_folio(src, GFP_KERNEL))
494 		return -EAGAIN;
495 	return migrate_folio(mapping, dst, src, mode);
496 }
497 #else
498 #define btree_migrate_folio NULL
499 #endif
500 
btree_writepages(struct address_space * mapping,struct writeback_control * wbc)501 static int btree_writepages(struct address_space *mapping,
502 			    struct writeback_control *wbc)
503 {
504 	int ret;
505 
506 	if (wbc->sync_mode == WB_SYNC_NONE) {
507 		struct btrfs_fs_info *fs_info;
508 
509 		if (wbc->for_kupdate)
510 			return 0;
511 
512 		fs_info = inode_to_fs_info(mapping->host);
513 		/* this is a bit racy, but that's ok */
514 		ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
515 					     BTRFS_DIRTY_METADATA_THRESH,
516 					     fs_info->dirty_metadata_batch);
517 		if (ret < 0)
518 			return 0;
519 	}
520 	return btree_write_cache_pages(mapping, wbc);
521 }
522 
btree_release_folio(struct folio * folio,gfp_t gfp_flags)523 static bool btree_release_folio(struct folio *folio, gfp_t gfp_flags)
524 {
525 	if (folio_test_writeback(folio) || folio_test_dirty(folio))
526 		return false;
527 
528 	return try_release_extent_buffer(folio);
529 }
530 
btree_invalidate_folio(struct folio * folio,size_t offset,size_t length)531 static void btree_invalidate_folio(struct folio *folio, size_t offset,
532 				 size_t length)
533 {
534 	struct extent_io_tree *tree;
535 
536 	tree = &folio_to_inode(folio)->io_tree;
537 	extent_invalidate_folio(tree, folio, offset);
538 	btree_release_folio(folio, GFP_NOFS);
539 	if (folio_get_private(folio)) {
540 		btrfs_warn(folio_to_fs_info(folio),
541 			   "folio private not zero on folio %llu",
542 			   (unsigned long long)folio_pos(folio));
543 		folio_detach_private(folio);
544 	}
545 }
546 
547 #ifdef DEBUG
btree_dirty_folio(struct address_space * mapping,struct folio * folio)548 static bool btree_dirty_folio(struct address_space *mapping,
549 		struct folio *folio)
550 {
551 	struct btrfs_fs_info *fs_info = inode_to_fs_info(mapping->host);
552 	struct btrfs_subpage_info *spi = fs_info->subpage_info;
553 	struct btrfs_subpage *subpage;
554 	struct extent_buffer *eb;
555 	int cur_bit = 0;
556 	u64 page_start = folio_pos(folio);
557 
558 	if (fs_info->sectorsize == PAGE_SIZE) {
559 		eb = folio_get_private(folio);
560 		BUG_ON(!eb);
561 		BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
562 		BUG_ON(!atomic_read(&eb->refs));
563 		btrfs_assert_tree_write_locked(eb);
564 		return filemap_dirty_folio(mapping, folio);
565 	}
566 
567 	ASSERT(spi);
568 	subpage = folio_get_private(folio);
569 
570 	for (cur_bit = spi->dirty_offset;
571 	     cur_bit < spi->dirty_offset + spi->bitmap_nr_bits;
572 	     cur_bit++) {
573 		unsigned long flags;
574 		u64 cur;
575 
576 		spin_lock_irqsave(&subpage->lock, flags);
577 		if (!test_bit(cur_bit, subpage->bitmaps)) {
578 			spin_unlock_irqrestore(&subpage->lock, flags);
579 			continue;
580 		}
581 		spin_unlock_irqrestore(&subpage->lock, flags);
582 		cur = page_start + cur_bit * fs_info->sectorsize;
583 
584 		eb = find_extent_buffer(fs_info, cur);
585 		ASSERT(eb);
586 		ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
587 		ASSERT(atomic_read(&eb->refs));
588 		btrfs_assert_tree_write_locked(eb);
589 		free_extent_buffer(eb);
590 
591 		cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits) - 1;
592 	}
593 	return filemap_dirty_folio(mapping, folio);
594 }
595 #else
596 #define btree_dirty_folio filemap_dirty_folio
597 #endif
598 
599 static const struct address_space_operations btree_aops = {
600 	.writepages	= btree_writepages,
601 	.release_folio	= btree_release_folio,
602 	.invalidate_folio = btree_invalidate_folio,
603 	.migrate_folio	= btree_migrate_folio,
604 	.dirty_folio	= btree_dirty_folio,
605 };
606 
btrfs_find_create_tree_block(struct btrfs_fs_info * fs_info,u64 bytenr,u64 owner_root,int level)607 struct extent_buffer *btrfs_find_create_tree_block(
608 						struct btrfs_fs_info *fs_info,
609 						u64 bytenr, u64 owner_root,
610 						int level)
611 {
612 	if (btrfs_is_testing(fs_info))
613 		return alloc_test_extent_buffer(fs_info, bytenr);
614 	return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
615 }
616 
617 /*
618  * Read tree block at logical address @bytenr and do variant basic but critical
619  * verification.
620  *
621  * @check:		expected tree parentness check, see comments of the
622  *			structure for details.
623  */
read_tree_block(struct btrfs_fs_info * fs_info,u64 bytenr,struct btrfs_tree_parent_check * check)624 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
625 				      struct btrfs_tree_parent_check *check)
626 {
627 	struct extent_buffer *buf = NULL;
628 	int ret;
629 
630 	ASSERT(check);
631 
632 	buf = btrfs_find_create_tree_block(fs_info, bytenr, check->owner_root,
633 					   check->level);
634 	if (IS_ERR(buf))
635 		return buf;
636 
637 	ret = btrfs_read_extent_buffer(buf, check);
638 	if (ret) {
639 		free_extent_buffer_stale(buf);
640 		return ERR_PTR(ret);
641 	}
642 	return buf;
643 
644 }
645 
__setup_root(struct btrfs_root * root,struct btrfs_fs_info * fs_info,u64 objectid)646 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
647 			 u64 objectid)
648 {
649 	bool dummy = btrfs_is_testing(fs_info);
650 
651 	memset(&root->root_key, 0, sizeof(root->root_key));
652 	memset(&root->root_item, 0, sizeof(root->root_item));
653 	memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
654 	root->fs_info = fs_info;
655 	root->root_key.objectid = objectid;
656 	root->node = NULL;
657 	root->commit_root = NULL;
658 	root->state = 0;
659 	RB_CLEAR_NODE(&root->rb_node);
660 
661 	btrfs_set_root_last_trans(root, 0);
662 	root->free_objectid = 0;
663 	root->nr_delalloc_inodes = 0;
664 	root->nr_ordered_extents = 0;
665 	xa_init(&root->inodes);
666 	xa_init(&root->delayed_nodes);
667 
668 	btrfs_init_root_block_rsv(root);
669 
670 	INIT_LIST_HEAD(&root->dirty_list);
671 	INIT_LIST_HEAD(&root->root_list);
672 	INIT_LIST_HEAD(&root->delalloc_inodes);
673 	INIT_LIST_HEAD(&root->delalloc_root);
674 	INIT_LIST_HEAD(&root->ordered_extents);
675 	INIT_LIST_HEAD(&root->ordered_root);
676 	INIT_LIST_HEAD(&root->reloc_dirty_list);
677 	spin_lock_init(&root->delalloc_lock);
678 	spin_lock_init(&root->ordered_extent_lock);
679 	spin_lock_init(&root->accounting_lock);
680 	spin_lock_init(&root->qgroup_meta_rsv_lock);
681 	mutex_init(&root->objectid_mutex);
682 	mutex_init(&root->log_mutex);
683 	mutex_init(&root->ordered_extent_mutex);
684 	mutex_init(&root->delalloc_mutex);
685 	init_waitqueue_head(&root->qgroup_flush_wait);
686 	init_waitqueue_head(&root->log_writer_wait);
687 	init_waitqueue_head(&root->log_commit_wait[0]);
688 	init_waitqueue_head(&root->log_commit_wait[1]);
689 	INIT_LIST_HEAD(&root->log_ctxs[0]);
690 	INIT_LIST_HEAD(&root->log_ctxs[1]);
691 	atomic_set(&root->log_commit[0], 0);
692 	atomic_set(&root->log_commit[1], 0);
693 	atomic_set(&root->log_writers, 0);
694 	atomic_set(&root->log_batch, 0);
695 	refcount_set(&root->refs, 1);
696 	atomic_set(&root->snapshot_force_cow, 0);
697 	atomic_set(&root->nr_swapfiles, 0);
698 	btrfs_set_root_log_transid(root, 0);
699 	root->log_transid_committed = -1;
700 	btrfs_set_root_last_log_commit(root, 0);
701 	root->anon_dev = 0;
702 	if (!dummy) {
703 		extent_io_tree_init(fs_info, &root->dirty_log_pages,
704 				    IO_TREE_ROOT_DIRTY_LOG_PAGES);
705 		extent_io_tree_init(fs_info, &root->log_csum_range,
706 				    IO_TREE_LOG_CSUM_RANGE);
707 	}
708 
709 	spin_lock_init(&root->root_item_lock);
710 	btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
711 #ifdef CONFIG_BTRFS_DEBUG
712 	INIT_LIST_HEAD(&root->leak_list);
713 	spin_lock(&fs_info->fs_roots_radix_lock);
714 	list_add_tail(&root->leak_list, &fs_info->allocated_roots);
715 	spin_unlock(&fs_info->fs_roots_radix_lock);
716 #endif
717 }
718 
btrfs_alloc_root(struct btrfs_fs_info * fs_info,u64 objectid,gfp_t flags)719 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
720 					   u64 objectid, gfp_t flags)
721 {
722 	struct btrfs_root *root = kzalloc(sizeof(*root), flags);
723 	if (root)
724 		__setup_root(root, fs_info, objectid);
725 	return root;
726 }
727 
728 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
729 /* Should only be used by the testing infrastructure */
btrfs_alloc_dummy_root(struct btrfs_fs_info * fs_info)730 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
731 {
732 	struct btrfs_root *root;
733 
734 	if (!fs_info)
735 		return ERR_PTR(-EINVAL);
736 
737 	root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
738 	if (!root)
739 		return ERR_PTR(-ENOMEM);
740 
741 	/* We don't use the stripesize in selftest, set it as sectorsize */
742 	root->alloc_bytenr = 0;
743 
744 	return root;
745 }
746 #endif
747 
global_root_cmp(struct rb_node * a_node,const struct rb_node * b_node)748 static int global_root_cmp(struct rb_node *a_node, const struct rb_node *b_node)
749 {
750 	const struct btrfs_root *a = rb_entry(a_node, struct btrfs_root, rb_node);
751 	const struct btrfs_root *b = rb_entry(b_node, struct btrfs_root, rb_node);
752 
753 	return btrfs_comp_cpu_keys(&a->root_key, &b->root_key);
754 }
755 
global_root_key_cmp(const void * k,const struct rb_node * node)756 static int global_root_key_cmp(const void *k, const struct rb_node *node)
757 {
758 	const struct btrfs_key *key = k;
759 	const struct btrfs_root *root = rb_entry(node, struct btrfs_root, rb_node);
760 
761 	return btrfs_comp_cpu_keys(key, &root->root_key);
762 }
763 
btrfs_global_root_insert(struct btrfs_root * root)764 int btrfs_global_root_insert(struct btrfs_root *root)
765 {
766 	struct btrfs_fs_info *fs_info = root->fs_info;
767 	struct rb_node *tmp;
768 	int ret = 0;
769 
770 	write_lock(&fs_info->global_root_lock);
771 	tmp = rb_find_add(&root->rb_node, &fs_info->global_root_tree, global_root_cmp);
772 	write_unlock(&fs_info->global_root_lock);
773 
774 	if (tmp) {
775 		ret = -EEXIST;
776 		btrfs_warn(fs_info, "global root %llu %llu already exists",
777 			   btrfs_root_id(root), root->root_key.offset);
778 	}
779 	return ret;
780 }
781 
btrfs_global_root_delete(struct btrfs_root * root)782 void btrfs_global_root_delete(struct btrfs_root *root)
783 {
784 	struct btrfs_fs_info *fs_info = root->fs_info;
785 
786 	write_lock(&fs_info->global_root_lock);
787 	rb_erase(&root->rb_node, &fs_info->global_root_tree);
788 	write_unlock(&fs_info->global_root_lock);
789 }
790 
btrfs_global_root(struct btrfs_fs_info * fs_info,struct btrfs_key * key)791 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
792 				     struct btrfs_key *key)
793 {
794 	struct rb_node *node;
795 	struct btrfs_root *root = NULL;
796 
797 	read_lock(&fs_info->global_root_lock);
798 	node = rb_find(key, &fs_info->global_root_tree, global_root_key_cmp);
799 	if (node)
800 		root = container_of(node, struct btrfs_root, rb_node);
801 	read_unlock(&fs_info->global_root_lock);
802 
803 	return root;
804 }
805 
btrfs_global_root_id(struct btrfs_fs_info * fs_info,u64 bytenr)806 static u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr)
807 {
808 	struct btrfs_block_group *block_group;
809 	u64 ret;
810 
811 	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
812 		return 0;
813 
814 	if (bytenr)
815 		block_group = btrfs_lookup_block_group(fs_info, bytenr);
816 	else
817 		block_group = btrfs_lookup_first_block_group(fs_info, bytenr);
818 	ASSERT(block_group);
819 	if (!block_group)
820 		return 0;
821 	ret = block_group->global_root_id;
822 	btrfs_put_block_group(block_group);
823 
824 	return ret;
825 }
826 
btrfs_csum_root(struct btrfs_fs_info * fs_info,u64 bytenr)827 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr)
828 {
829 	struct btrfs_key key = {
830 		.objectid = BTRFS_CSUM_TREE_OBJECTID,
831 		.type = BTRFS_ROOT_ITEM_KEY,
832 		.offset = btrfs_global_root_id(fs_info, bytenr),
833 	};
834 
835 	return btrfs_global_root(fs_info, &key);
836 }
837 
btrfs_extent_root(struct btrfs_fs_info * fs_info,u64 bytenr)838 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr)
839 {
840 	struct btrfs_key key = {
841 		.objectid = BTRFS_EXTENT_TREE_OBJECTID,
842 		.type = BTRFS_ROOT_ITEM_KEY,
843 		.offset = btrfs_global_root_id(fs_info, bytenr),
844 	};
845 
846 	return btrfs_global_root(fs_info, &key);
847 }
848 
btrfs_create_tree(struct btrfs_trans_handle * trans,u64 objectid)849 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
850 				     u64 objectid)
851 {
852 	struct btrfs_fs_info *fs_info = trans->fs_info;
853 	struct extent_buffer *leaf;
854 	struct btrfs_root *tree_root = fs_info->tree_root;
855 	struct btrfs_root *root;
856 	struct btrfs_key key;
857 	unsigned int nofs_flag;
858 	int ret = 0;
859 
860 	/*
861 	 * We're holding a transaction handle, so use a NOFS memory allocation
862 	 * context to avoid deadlock if reclaim happens.
863 	 */
864 	nofs_flag = memalloc_nofs_save();
865 	root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
866 	memalloc_nofs_restore(nofs_flag);
867 	if (!root)
868 		return ERR_PTR(-ENOMEM);
869 
870 	root->root_key.objectid = objectid;
871 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
872 	root->root_key.offset = 0;
873 
874 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
875 				      0, BTRFS_NESTING_NORMAL);
876 	if (IS_ERR(leaf)) {
877 		ret = PTR_ERR(leaf);
878 		leaf = NULL;
879 		goto fail;
880 	}
881 
882 	root->node = leaf;
883 	btrfs_mark_buffer_dirty(trans, leaf);
884 
885 	root->commit_root = btrfs_root_node(root);
886 	set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
887 
888 	btrfs_set_root_flags(&root->root_item, 0);
889 	btrfs_set_root_limit(&root->root_item, 0);
890 	btrfs_set_root_bytenr(&root->root_item, leaf->start);
891 	btrfs_set_root_generation(&root->root_item, trans->transid);
892 	btrfs_set_root_level(&root->root_item, 0);
893 	btrfs_set_root_refs(&root->root_item, 1);
894 	btrfs_set_root_used(&root->root_item, leaf->len);
895 	btrfs_set_root_last_snapshot(&root->root_item, 0);
896 	btrfs_set_root_dirid(&root->root_item, 0);
897 	if (is_fstree(objectid))
898 		generate_random_guid(root->root_item.uuid);
899 	else
900 		export_guid(root->root_item.uuid, &guid_null);
901 	btrfs_set_root_drop_level(&root->root_item, 0);
902 
903 	btrfs_tree_unlock(leaf);
904 
905 	key.objectid = objectid;
906 	key.type = BTRFS_ROOT_ITEM_KEY;
907 	key.offset = 0;
908 	ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
909 	if (ret)
910 		goto fail;
911 
912 	return root;
913 
914 fail:
915 	btrfs_put_root(root);
916 
917 	return ERR_PTR(ret);
918 }
919 
alloc_log_tree(struct btrfs_fs_info * fs_info)920 static struct btrfs_root *alloc_log_tree(struct btrfs_fs_info *fs_info)
921 {
922 	struct btrfs_root *root;
923 
924 	root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
925 	if (!root)
926 		return ERR_PTR(-ENOMEM);
927 
928 	root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
929 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
930 	root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
931 
932 	return root;
933 }
934 
btrfs_alloc_log_tree_node(struct btrfs_trans_handle * trans,struct btrfs_root * root)935 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
936 			      struct btrfs_root *root)
937 {
938 	struct extent_buffer *leaf;
939 
940 	/*
941 	 * DON'T set SHAREABLE bit for log trees.
942 	 *
943 	 * Log trees are not exposed to user space thus can't be snapshotted,
944 	 * and they go away before a real commit is actually done.
945 	 *
946 	 * They do store pointers to file data extents, and those reference
947 	 * counts still get updated (along with back refs to the log tree).
948 	 */
949 
950 	leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
951 			NULL, 0, 0, 0, 0, BTRFS_NESTING_NORMAL);
952 	if (IS_ERR(leaf))
953 		return PTR_ERR(leaf);
954 
955 	root->node = leaf;
956 
957 	btrfs_mark_buffer_dirty(trans, root->node);
958 	btrfs_tree_unlock(root->node);
959 
960 	return 0;
961 }
962 
btrfs_init_log_root_tree(struct btrfs_trans_handle * trans,struct btrfs_fs_info * fs_info)963 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
964 			     struct btrfs_fs_info *fs_info)
965 {
966 	struct btrfs_root *log_root;
967 
968 	log_root = alloc_log_tree(fs_info);
969 	if (IS_ERR(log_root))
970 		return PTR_ERR(log_root);
971 
972 	if (!btrfs_is_zoned(fs_info)) {
973 		int ret = btrfs_alloc_log_tree_node(trans, log_root);
974 
975 		if (ret) {
976 			btrfs_put_root(log_root);
977 			return ret;
978 		}
979 	}
980 
981 	WARN_ON(fs_info->log_root_tree);
982 	fs_info->log_root_tree = log_root;
983 	return 0;
984 }
985 
btrfs_add_log_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root)986 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
987 		       struct btrfs_root *root)
988 {
989 	struct btrfs_fs_info *fs_info = root->fs_info;
990 	struct btrfs_root *log_root;
991 	struct btrfs_inode_item *inode_item;
992 	int ret;
993 
994 	log_root = alloc_log_tree(fs_info);
995 	if (IS_ERR(log_root))
996 		return PTR_ERR(log_root);
997 
998 	ret = btrfs_alloc_log_tree_node(trans, log_root);
999 	if (ret) {
1000 		btrfs_put_root(log_root);
1001 		return ret;
1002 	}
1003 
1004 	btrfs_set_root_last_trans(log_root, trans->transid);
1005 	log_root->root_key.offset = btrfs_root_id(root);
1006 
1007 	inode_item = &log_root->root_item.inode;
1008 	btrfs_set_stack_inode_generation(inode_item, 1);
1009 	btrfs_set_stack_inode_size(inode_item, 3);
1010 	btrfs_set_stack_inode_nlink(inode_item, 1);
1011 	btrfs_set_stack_inode_nbytes(inode_item,
1012 				     fs_info->nodesize);
1013 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1014 
1015 	btrfs_set_root_node(&log_root->root_item, log_root->node);
1016 
1017 	WARN_ON(root->log_root);
1018 	root->log_root = log_root;
1019 	btrfs_set_root_log_transid(root, 0);
1020 	root->log_transid_committed = -1;
1021 	btrfs_set_root_last_log_commit(root, 0);
1022 	return 0;
1023 }
1024 
read_tree_root_path(struct btrfs_root * tree_root,struct btrfs_path * path,const struct btrfs_key * key)1025 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1026 					      struct btrfs_path *path,
1027 					      const struct btrfs_key *key)
1028 {
1029 	struct btrfs_root *root;
1030 	struct btrfs_tree_parent_check check = { 0 };
1031 	struct btrfs_fs_info *fs_info = tree_root->fs_info;
1032 	u64 generation;
1033 	int ret;
1034 	int level;
1035 
1036 	root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1037 	if (!root)
1038 		return ERR_PTR(-ENOMEM);
1039 
1040 	ret = btrfs_find_root(tree_root, key, path,
1041 			      &root->root_item, &root->root_key);
1042 	if (ret) {
1043 		if (ret > 0)
1044 			ret = -ENOENT;
1045 		goto fail;
1046 	}
1047 
1048 	generation = btrfs_root_generation(&root->root_item);
1049 	level = btrfs_root_level(&root->root_item);
1050 	check.level = level;
1051 	check.transid = generation;
1052 	check.owner_root = key->objectid;
1053 	root->node = read_tree_block(fs_info, btrfs_root_bytenr(&root->root_item),
1054 				     &check);
1055 	if (IS_ERR(root->node)) {
1056 		ret = PTR_ERR(root->node);
1057 		root->node = NULL;
1058 		goto fail;
1059 	}
1060 	if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1061 		ret = -EIO;
1062 		goto fail;
1063 	}
1064 
1065 	/*
1066 	 * For real fs, and not log/reloc trees, root owner must
1067 	 * match its root node owner
1068 	 */
1069 	if (!btrfs_is_testing(fs_info) &&
1070 	    btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID &&
1071 	    btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID &&
1072 	    btrfs_root_id(root) != btrfs_header_owner(root->node)) {
1073 		btrfs_crit(fs_info,
1074 "root=%llu block=%llu, tree root owner mismatch, have %llu expect %llu",
1075 			   btrfs_root_id(root), root->node->start,
1076 			   btrfs_header_owner(root->node),
1077 			   btrfs_root_id(root));
1078 		ret = -EUCLEAN;
1079 		goto fail;
1080 	}
1081 	root->commit_root = btrfs_root_node(root);
1082 	return root;
1083 fail:
1084 	btrfs_put_root(root);
1085 	return ERR_PTR(ret);
1086 }
1087 
btrfs_read_tree_root(struct btrfs_root * tree_root,const struct btrfs_key * key)1088 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1089 					const struct btrfs_key *key)
1090 {
1091 	struct btrfs_root *root;
1092 	struct btrfs_path *path;
1093 
1094 	path = btrfs_alloc_path();
1095 	if (!path)
1096 		return ERR_PTR(-ENOMEM);
1097 	root = read_tree_root_path(tree_root, path, key);
1098 	btrfs_free_path(path);
1099 
1100 	return root;
1101 }
1102 
1103 /*
1104  * Initialize subvolume root in-memory structure
1105  *
1106  * @anon_dev:	anonymous device to attach to the root, if zero, allocate new
1107  */
btrfs_init_fs_root(struct btrfs_root * root,dev_t anon_dev)1108 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1109 {
1110 	int ret;
1111 
1112 	btrfs_drew_lock_init(&root->snapshot_lock);
1113 
1114 	if (btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID &&
1115 	    !btrfs_is_data_reloc_root(root) &&
1116 	    is_fstree(btrfs_root_id(root))) {
1117 		set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1118 		btrfs_check_and_init_root_item(&root->root_item);
1119 	}
1120 
1121 	/*
1122 	 * Don't assign anonymous block device to roots that are not exposed to
1123 	 * userspace, the id pool is limited to 1M
1124 	 */
1125 	if (is_fstree(btrfs_root_id(root)) &&
1126 	    btrfs_root_refs(&root->root_item) > 0) {
1127 		if (!anon_dev) {
1128 			ret = get_anon_bdev(&root->anon_dev);
1129 			if (ret)
1130 				goto fail;
1131 		} else {
1132 			root->anon_dev = anon_dev;
1133 		}
1134 	}
1135 
1136 	mutex_lock(&root->objectid_mutex);
1137 	ret = btrfs_init_root_free_objectid(root);
1138 	if (ret) {
1139 		mutex_unlock(&root->objectid_mutex);
1140 		goto fail;
1141 	}
1142 
1143 	ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1144 
1145 	mutex_unlock(&root->objectid_mutex);
1146 
1147 	return 0;
1148 fail:
1149 	/* The caller is responsible to call btrfs_free_fs_root */
1150 	return ret;
1151 }
1152 
btrfs_lookup_fs_root(struct btrfs_fs_info * fs_info,u64 root_id)1153 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1154 					       u64 root_id)
1155 {
1156 	struct btrfs_root *root;
1157 
1158 	spin_lock(&fs_info->fs_roots_radix_lock);
1159 	root = radix_tree_lookup(&fs_info->fs_roots_radix,
1160 				 (unsigned long)root_id);
1161 	root = btrfs_grab_root(root);
1162 	spin_unlock(&fs_info->fs_roots_radix_lock);
1163 	return root;
1164 }
1165 
btrfs_get_global_root(struct btrfs_fs_info * fs_info,u64 objectid)1166 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1167 						u64 objectid)
1168 {
1169 	struct btrfs_key key = {
1170 		.objectid = objectid,
1171 		.type = BTRFS_ROOT_ITEM_KEY,
1172 		.offset = 0,
1173 	};
1174 
1175 	switch (objectid) {
1176 	case BTRFS_ROOT_TREE_OBJECTID:
1177 		return btrfs_grab_root(fs_info->tree_root);
1178 	case BTRFS_EXTENT_TREE_OBJECTID:
1179 		return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1180 	case BTRFS_CHUNK_TREE_OBJECTID:
1181 		return btrfs_grab_root(fs_info->chunk_root);
1182 	case BTRFS_DEV_TREE_OBJECTID:
1183 		return btrfs_grab_root(fs_info->dev_root);
1184 	case BTRFS_CSUM_TREE_OBJECTID:
1185 		return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1186 	case BTRFS_QUOTA_TREE_OBJECTID:
1187 		return btrfs_grab_root(fs_info->quota_root);
1188 	case BTRFS_UUID_TREE_OBJECTID:
1189 		return btrfs_grab_root(fs_info->uuid_root);
1190 	case BTRFS_BLOCK_GROUP_TREE_OBJECTID:
1191 		return btrfs_grab_root(fs_info->block_group_root);
1192 	case BTRFS_FREE_SPACE_TREE_OBJECTID:
1193 		return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1194 	case BTRFS_RAID_STRIPE_TREE_OBJECTID:
1195 		return btrfs_grab_root(fs_info->stripe_root);
1196 	default:
1197 		return NULL;
1198 	}
1199 }
1200 
btrfs_insert_fs_root(struct btrfs_fs_info * fs_info,struct btrfs_root * root)1201 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1202 			 struct btrfs_root *root)
1203 {
1204 	int ret;
1205 
1206 	ret = radix_tree_preload(GFP_NOFS);
1207 	if (ret)
1208 		return ret;
1209 
1210 	spin_lock(&fs_info->fs_roots_radix_lock);
1211 	ret = radix_tree_insert(&fs_info->fs_roots_radix,
1212 				(unsigned long)btrfs_root_id(root),
1213 				root);
1214 	if (ret == 0) {
1215 		btrfs_grab_root(root);
1216 		set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1217 	}
1218 	spin_unlock(&fs_info->fs_roots_radix_lock);
1219 	radix_tree_preload_end();
1220 
1221 	return ret;
1222 }
1223 
btrfs_check_leaked_roots(const struct btrfs_fs_info * fs_info)1224 void btrfs_check_leaked_roots(const struct btrfs_fs_info *fs_info)
1225 {
1226 #ifdef CONFIG_BTRFS_DEBUG
1227 	struct btrfs_root *root;
1228 
1229 	while (!list_empty(&fs_info->allocated_roots)) {
1230 		char buf[BTRFS_ROOT_NAME_BUF_LEN];
1231 
1232 		root = list_first_entry(&fs_info->allocated_roots,
1233 					struct btrfs_root, leak_list);
1234 		btrfs_err(fs_info, "leaked root %s refcount %d",
1235 			  btrfs_root_name(&root->root_key, buf),
1236 			  refcount_read(&root->refs));
1237 		WARN_ON_ONCE(1);
1238 		while (refcount_read(&root->refs) > 1)
1239 			btrfs_put_root(root);
1240 		btrfs_put_root(root);
1241 	}
1242 #endif
1243 }
1244 
free_global_roots(struct btrfs_fs_info * fs_info)1245 static void free_global_roots(struct btrfs_fs_info *fs_info)
1246 {
1247 	struct btrfs_root *root;
1248 	struct rb_node *node;
1249 
1250 	while ((node = rb_first_postorder(&fs_info->global_root_tree)) != NULL) {
1251 		root = rb_entry(node, struct btrfs_root, rb_node);
1252 		rb_erase(&root->rb_node, &fs_info->global_root_tree);
1253 		btrfs_put_root(root);
1254 	}
1255 }
1256 
btrfs_free_fs_info(struct btrfs_fs_info * fs_info)1257 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1258 {
1259 	struct percpu_counter *em_counter = &fs_info->evictable_extent_maps;
1260 
1261 	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1262 	percpu_counter_destroy(&fs_info->delalloc_bytes);
1263 	percpu_counter_destroy(&fs_info->ordered_bytes);
1264 	if (percpu_counter_initialized(em_counter))
1265 		ASSERT(percpu_counter_sum_positive(em_counter) == 0);
1266 	percpu_counter_destroy(em_counter);
1267 	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1268 	btrfs_free_csum_hash(fs_info);
1269 	btrfs_free_stripe_hash_table(fs_info);
1270 	btrfs_free_ref_cache(fs_info);
1271 	kfree(fs_info->balance_ctl);
1272 	kfree(fs_info->delayed_root);
1273 	free_global_roots(fs_info);
1274 	btrfs_put_root(fs_info->tree_root);
1275 	btrfs_put_root(fs_info->chunk_root);
1276 	btrfs_put_root(fs_info->dev_root);
1277 	btrfs_put_root(fs_info->quota_root);
1278 	btrfs_put_root(fs_info->uuid_root);
1279 	btrfs_put_root(fs_info->fs_root);
1280 	btrfs_put_root(fs_info->data_reloc_root);
1281 	btrfs_put_root(fs_info->block_group_root);
1282 	btrfs_put_root(fs_info->stripe_root);
1283 	btrfs_check_leaked_roots(fs_info);
1284 	btrfs_extent_buffer_leak_debug_check(fs_info);
1285 	kfree(fs_info->super_copy);
1286 	kfree(fs_info->super_for_commit);
1287 	kvfree(fs_info);
1288 }
1289 
1290 
1291 /*
1292  * Get an in-memory reference of a root structure.
1293  *
1294  * For essential trees like root/extent tree, we grab it from fs_info directly.
1295  * For subvolume trees, we check the cached filesystem roots first. If not
1296  * found, then read it from disk and add it to cached fs roots.
1297  *
1298  * Caller should release the root by calling btrfs_put_root() after the usage.
1299  *
1300  * NOTE: Reloc and log trees can't be read by this function as they share the
1301  *	 same root objectid.
1302  *
1303  * @objectid:	root id
1304  * @anon_dev:	preallocated anonymous block device number for new roots,
1305  *		pass NULL for a new allocation.
1306  * @check_ref:	whether to check root item references, If true, return -ENOENT
1307  *		for orphan roots
1308  */
btrfs_get_root_ref(struct btrfs_fs_info * fs_info,u64 objectid,dev_t * anon_dev,bool check_ref)1309 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1310 					     u64 objectid, dev_t *anon_dev,
1311 					     bool check_ref)
1312 {
1313 	struct btrfs_root *root;
1314 	struct btrfs_path *path;
1315 	struct btrfs_key key;
1316 	int ret;
1317 
1318 	root = btrfs_get_global_root(fs_info, objectid);
1319 	if (root)
1320 		return root;
1321 
1322 	/*
1323 	 * If we're called for non-subvolume trees, and above function didn't
1324 	 * find one, do not try to read it from disk.
1325 	 *
1326 	 * This is namely for free-space-tree and quota tree, which can change
1327 	 * at runtime and should only be grabbed from fs_info.
1328 	 */
1329 	if (!is_fstree(objectid) && objectid != BTRFS_DATA_RELOC_TREE_OBJECTID)
1330 		return ERR_PTR(-ENOENT);
1331 again:
1332 	root = btrfs_lookup_fs_root(fs_info, objectid);
1333 	if (root) {
1334 		/*
1335 		 * Some other caller may have read out the newly inserted
1336 		 * subvolume already (for things like backref walk etc).  Not
1337 		 * that common but still possible.  In that case, we just need
1338 		 * to free the anon_dev.
1339 		 */
1340 		if (unlikely(anon_dev && *anon_dev)) {
1341 			free_anon_bdev(*anon_dev);
1342 			*anon_dev = 0;
1343 		}
1344 
1345 		if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1346 			btrfs_put_root(root);
1347 			return ERR_PTR(-ENOENT);
1348 		}
1349 		return root;
1350 	}
1351 
1352 	key.objectid = objectid;
1353 	key.type = BTRFS_ROOT_ITEM_KEY;
1354 	key.offset = (u64)-1;
1355 	root = btrfs_read_tree_root(fs_info->tree_root, &key);
1356 	if (IS_ERR(root))
1357 		return root;
1358 
1359 	if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1360 		ret = -ENOENT;
1361 		goto fail;
1362 	}
1363 
1364 	ret = btrfs_init_fs_root(root, anon_dev ? *anon_dev : 0);
1365 	if (ret)
1366 		goto fail;
1367 
1368 	path = btrfs_alloc_path();
1369 	if (!path) {
1370 		ret = -ENOMEM;
1371 		goto fail;
1372 	}
1373 	key.objectid = BTRFS_ORPHAN_OBJECTID;
1374 	key.type = BTRFS_ORPHAN_ITEM_KEY;
1375 	key.offset = objectid;
1376 
1377 	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1378 	btrfs_free_path(path);
1379 	if (ret < 0)
1380 		goto fail;
1381 	if (ret == 0)
1382 		set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1383 
1384 	ret = btrfs_insert_fs_root(fs_info, root);
1385 	if (ret) {
1386 		if (ret == -EEXIST) {
1387 			btrfs_put_root(root);
1388 			goto again;
1389 		}
1390 		goto fail;
1391 	}
1392 	return root;
1393 fail:
1394 	/*
1395 	 * If our caller provided us an anonymous device, then it's his
1396 	 * responsibility to free it in case we fail. So we have to set our
1397 	 * root's anon_dev to 0 to avoid a double free, once by btrfs_put_root()
1398 	 * and once again by our caller.
1399 	 */
1400 	if (anon_dev && *anon_dev)
1401 		root->anon_dev = 0;
1402 	btrfs_put_root(root);
1403 	return ERR_PTR(ret);
1404 }
1405 
1406 /*
1407  * Get in-memory reference of a root structure
1408  *
1409  * @objectid:	tree objectid
1410  * @check_ref:	if set, verify that the tree exists and the item has at least
1411  *		one reference
1412  */
btrfs_get_fs_root(struct btrfs_fs_info * fs_info,u64 objectid,bool check_ref)1413 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1414 				     u64 objectid, bool check_ref)
1415 {
1416 	return btrfs_get_root_ref(fs_info, objectid, NULL, check_ref);
1417 }
1418 
1419 /*
1420  * Get in-memory reference of a root structure, created as new, optionally pass
1421  * the anonymous block device id
1422  *
1423  * @objectid:	tree objectid
1424  * @anon_dev:	if NULL, allocate a new anonymous block device or use the
1425  *		parameter value if not NULL
1426  */
btrfs_get_new_fs_root(struct btrfs_fs_info * fs_info,u64 objectid,dev_t * anon_dev)1427 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1428 					 u64 objectid, dev_t *anon_dev)
1429 {
1430 	return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1431 }
1432 
1433 /*
1434  * Return a root for the given objectid.
1435  *
1436  * @fs_info:	the fs_info
1437  * @objectid:	the objectid we need to lookup
1438  *
1439  * This is exclusively used for backref walking, and exists specifically because
1440  * of how qgroups does lookups.  Qgroups will do a backref lookup at delayed ref
1441  * creation time, which means we may have to read the tree_root in order to look
1442  * up a fs root that is not in memory.  If the root is not in memory we will
1443  * read the tree root commit root and look up the fs root from there.  This is a
1444  * temporary root, it will not be inserted into the radix tree as it doesn't
1445  * have the most uptodate information, it'll simply be discarded once the
1446  * backref code is finished using the root.
1447  */
btrfs_get_fs_root_commit_root(struct btrfs_fs_info * fs_info,struct btrfs_path * path,u64 objectid)1448 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1449 						 struct btrfs_path *path,
1450 						 u64 objectid)
1451 {
1452 	struct btrfs_root *root;
1453 	struct btrfs_key key;
1454 
1455 	ASSERT(path->search_commit_root && path->skip_locking);
1456 
1457 	/*
1458 	 * This can return -ENOENT if we ask for a root that doesn't exist, but
1459 	 * since this is called via the backref walking code we won't be looking
1460 	 * up a root that doesn't exist, unless there's corruption.  So if root
1461 	 * != NULL just return it.
1462 	 */
1463 	root = btrfs_get_global_root(fs_info, objectid);
1464 	if (root)
1465 		return root;
1466 
1467 	root = btrfs_lookup_fs_root(fs_info, objectid);
1468 	if (root)
1469 		return root;
1470 
1471 	key.objectid = objectid;
1472 	key.type = BTRFS_ROOT_ITEM_KEY;
1473 	key.offset = (u64)-1;
1474 	root = read_tree_root_path(fs_info->tree_root, path, &key);
1475 	btrfs_release_path(path);
1476 
1477 	return root;
1478 }
1479 
cleaner_kthread(void * arg)1480 static int cleaner_kthread(void *arg)
1481 {
1482 	struct btrfs_fs_info *fs_info = arg;
1483 	int again;
1484 
1485 	while (1) {
1486 		again = 0;
1487 
1488 		set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1489 
1490 		/* Make the cleaner go to sleep early. */
1491 		if (btrfs_need_cleaner_sleep(fs_info))
1492 			goto sleep;
1493 
1494 		/*
1495 		 * Do not do anything if we might cause open_ctree() to block
1496 		 * before we have finished mounting the filesystem.
1497 		 */
1498 		if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1499 			goto sleep;
1500 
1501 		if (!mutex_trylock(&fs_info->cleaner_mutex))
1502 			goto sleep;
1503 
1504 		/*
1505 		 * Avoid the problem that we change the status of the fs
1506 		 * during the above check and trylock.
1507 		 */
1508 		if (btrfs_need_cleaner_sleep(fs_info)) {
1509 			mutex_unlock(&fs_info->cleaner_mutex);
1510 			goto sleep;
1511 		}
1512 
1513 		if (test_and_clear_bit(BTRFS_FS_FEATURE_CHANGED, &fs_info->flags))
1514 			btrfs_sysfs_feature_update(fs_info);
1515 
1516 		btrfs_run_delayed_iputs(fs_info);
1517 
1518 		again = btrfs_clean_one_deleted_snapshot(fs_info);
1519 		mutex_unlock(&fs_info->cleaner_mutex);
1520 
1521 		/*
1522 		 * The defragger has dealt with the R/O remount and umount,
1523 		 * needn't do anything special here.
1524 		 */
1525 		btrfs_run_defrag_inodes(fs_info);
1526 
1527 		/*
1528 		 * Acquires fs_info->reclaim_bgs_lock to avoid racing
1529 		 * with relocation (btrfs_relocate_chunk) and relocation
1530 		 * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1531 		 * after acquiring fs_info->reclaim_bgs_lock. So we
1532 		 * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1533 		 * unused block groups.
1534 		 */
1535 		btrfs_delete_unused_bgs(fs_info);
1536 
1537 		/*
1538 		 * Reclaim block groups in the reclaim_bgs list after we deleted
1539 		 * all unused block_groups. This possibly gives us some more free
1540 		 * space.
1541 		 */
1542 		btrfs_reclaim_bgs(fs_info);
1543 sleep:
1544 		clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1545 		if (kthread_should_park())
1546 			kthread_parkme();
1547 		if (kthread_should_stop())
1548 			return 0;
1549 		if (!again) {
1550 			set_current_state(TASK_INTERRUPTIBLE);
1551 			schedule();
1552 			__set_current_state(TASK_RUNNING);
1553 		}
1554 	}
1555 }
1556 
transaction_kthread(void * arg)1557 static int transaction_kthread(void *arg)
1558 {
1559 	struct btrfs_root *root = arg;
1560 	struct btrfs_fs_info *fs_info = root->fs_info;
1561 	struct btrfs_trans_handle *trans;
1562 	struct btrfs_transaction *cur;
1563 	u64 transid;
1564 	time64_t delta;
1565 	unsigned long delay;
1566 	bool cannot_commit;
1567 
1568 	do {
1569 		cannot_commit = false;
1570 		delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1571 		mutex_lock(&fs_info->transaction_kthread_mutex);
1572 
1573 		spin_lock(&fs_info->trans_lock);
1574 		cur = fs_info->running_transaction;
1575 		if (!cur) {
1576 			spin_unlock(&fs_info->trans_lock);
1577 			goto sleep;
1578 		}
1579 
1580 		delta = ktime_get_seconds() - cur->start_time;
1581 		if (!test_and_clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags) &&
1582 		    cur->state < TRANS_STATE_COMMIT_PREP &&
1583 		    delta < fs_info->commit_interval) {
1584 			spin_unlock(&fs_info->trans_lock);
1585 			delay -= msecs_to_jiffies((delta - 1) * 1000);
1586 			delay = min(delay,
1587 				    msecs_to_jiffies(fs_info->commit_interval * 1000));
1588 			goto sleep;
1589 		}
1590 		transid = cur->transid;
1591 		spin_unlock(&fs_info->trans_lock);
1592 
1593 		/* If the file system is aborted, this will always fail. */
1594 		trans = btrfs_attach_transaction(root);
1595 		if (IS_ERR(trans)) {
1596 			if (PTR_ERR(trans) != -ENOENT)
1597 				cannot_commit = true;
1598 			goto sleep;
1599 		}
1600 		if (transid == trans->transid) {
1601 			btrfs_commit_transaction(trans);
1602 		} else {
1603 			btrfs_end_transaction(trans);
1604 		}
1605 sleep:
1606 		wake_up_process(fs_info->cleaner_kthread);
1607 		mutex_unlock(&fs_info->transaction_kthread_mutex);
1608 
1609 		if (BTRFS_FS_ERROR(fs_info))
1610 			btrfs_cleanup_transaction(fs_info);
1611 		if (!kthread_should_stop() &&
1612 				(!btrfs_transaction_blocked(fs_info) ||
1613 				 cannot_commit))
1614 			schedule_timeout_interruptible(delay);
1615 	} while (!kthread_should_stop());
1616 	return 0;
1617 }
1618 
1619 /*
1620  * This will find the highest generation in the array of root backups.  The
1621  * index of the highest array is returned, or -EINVAL if we can't find
1622  * anything.
1623  *
1624  * We check to make sure the array is valid by comparing the
1625  * generation of the latest  root in the array with the generation
1626  * in the super block.  If they don't match we pitch it.
1627  */
find_newest_super_backup(struct btrfs_fs_info * info)1628 static int find_newest_super_backup(struct btrfs_fs_info *info)
1629 {
1630 	const u64 newest_gen = btrfs_super_generation(info->super_copy);
1631 	u64 cur;
1632 	struct btrfs_root_backup *root_backup;
1633 	int i;
1634 
1635 	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1636 		root_backup = info->super_copy->super_roots + i;
1637 		cur = btrfs_backup_tree_root_gen(root_backup);
1638 		if (cur == newest_gen)
1639 			return i;
1640 	}
1641 
1642 	return -EINVAL;
1643 }
1644 
1645 /*
1646  * copy all the root pointers into the super backup array.
1647  * this will bump the backup pointer by one when it is
1648  * done
1649  */
backup_super_roots(struct btrfs_fs_info * info)1650 static void backup_super_roots(struct btrfs_fs_info *info)
1651 {
1652 	const int next_backup = info->backup_root_index;
1653 	struct btrfs_root_backup *root_backup;
1654 
1655 	root_backup = info->super_for_commit->super_roots + next_backup;
1656 
1657 	/*
1658 	 * make sure all of our padding and empty slots get zero filled
1659 	 * regardless of which ones we use today
1660 	 */
1661 	memset(root_backup, 0, sizeof(*root_backup));
1662 
1663 	info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1664 
1665 	btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1666 	btrfs_set_backup_tree_root_gen(root_backup,
1667 			       btrfs_header_generation(info->tree_root->node));
1668 
1669 	btrfs_set_backup_tree_root_level(root_backup,
1670 			       btrfs_header_level(info->tree_root->node));
1671 
1672 	btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1673 	btrfs_set_backup_chunk_root_gen(root_backup,
1674 			       btrfs_header_generation(info->chunk_root->node));
1675 	btrfs_set_backup_chunk_root_level(root_backup,
1676 			       btrfs_header_level(info->chunk_root->node));
1677 
1678 	if (!btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE)) {
1679 		struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
1680 		struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
1681 
1682 		btrfs_set_backup_extent_root(root_backup,
1683 					     extent_root->node->start);
1684 		btrfs_set_backup_extent_root_gen(root_backup,
1685 				btrfs_header_generation(extent_root->node));
1686 		btrfs_set_backup_extent_root_level(root_backup,
1687 					btrfs_header_level(extent_root->node));
1688 
1689 		btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
1690 		btrfs_set_backup_csum_root_gen(root_backup,
1691 					       btrfs_header_generation(csum_root->node));
1692 		btrfs_set_backup_csum_root_level(root_backup,
1693 						 btrfs_header_level(csum_root->node));
1694 	}
1695 
1696 	/*
1697 	 * we might commit during log recovery, which happens before we set
1698 	 * the fs_root.  Make sure it is valid before we fill it in.
1699 	 */
1700 	if (info->fs_root && info->fs_root->node) {
1701 		btrfs_set_backup_fs_root(root_backup,
1702 					 info->fs_root->node->start);
1703 		btrfs_set_backup_fs_root_gen(root_backup,
1704 			       btrfs_header_generation(info->fs_root->node));
1705 		btrfs_set_backup_fs_root_level(root_backup,
1706 			       btrfs_header_level(info->fs_root->node));
1707 	}
1708 
1709 	btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1710 	btrfs_set_backup_dev_root_gen(root_backup,
1711 			       btrfs_header_generation(info->dev_root->node));
1712 	btrfs_set_backup_dev_root_level(root_backup,
1713 				       btrfs_header_level(info->dev_root->node));
1714 
1715 	btrfs_set_backup_total_bytes(root_backup,
1716 			     btrfs_super_total_bytes(info->super_copy));
1717 	btrfs_set_backup_bytes_used(root_backup,
1718 			     btrfs_super_bytes_used(info->super_copy));
1719 	btrfs_set_backup_num_devices(root_backup,
1720 			     btrfs_super_num_devices(info->super_copy));
1721 
1722 	/*
1723 	 * if we don't copy this out to the super_copy, it won't get remembered
1724 	 * for the next commit
1725 	 */
1726 	memcpy(&info->super_copy->super_roots,
1727 	       &info->super_for_commit->super_roots,
1728 	       sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1729 }
1730 
1731 /*
1732  * Reads a backup root based on the passed priority. Prio 0 is the newest, prio
1733  * 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
1734  *
1735  * @fs_info:  filesystem whose backup roots need to be read
1736  * @priority: priority of backup root required
1737  *
1738  * Returns backup root index on success and -EINVAL otherwise.
1739  */
read_backup_root(struct btrfs_fs_info * fs_info,u8 priority)1740 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
1741 {
1742 	int backup_index = find_newest_super_backup(fs_info);
1743 	struct btrfs_super_block *super = fs_info->super_copy;
1744 	struct btrfs_root_backup *root_backup;
1745 
1746 	if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
1747 		if (priority == 0)
1748 			return backup_index;
1749 
1750 		backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
1751 		backup_index %= BTRFS_NUM_BACKUP_ROOTS;
1752 	} else {
1753 		return -EINVAL;
1754 	}
1755 
1756 	root_backup = super->super_roots + backup_index;
1757 
1758 	btrfs_set_super_generation(super,
1759 				   btrfs_backup_tree_root_gen(root_backup));
1760 	btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1761 	btrfs_set_super_root_level(super,
1762 				   btrfs_backup_tree_root_level(root_backup));
1763 	btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1764 
1765 	/*
1766 	 * Fixme: the total bytes and num_devices need to match or we should
1767 	 * need a fsck
1768 	 */
1769 	btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
1770 	btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
1771 
1772 	return backup_index;
1773 }
1774 
1775 /* helper to cleanup workers */
btrfs_stop_all_workers(struct btrfs_fs_info * fs_info)1776 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
1777 {
1778 	btrfs_destroy_workqueue(fs_info->fixup_workers);
1779 	btrfs_destroy_workqueue(fs_info->delalloc_workers);
1780 	btrfs_destroy_workqueue(fs_info->workers);
1781 	if (fs_info->endio_workers)
1782 		destroy_workqueue(fs_info->endio_workers);
1783 	if (fs_info->rmw_workers)
1784 		destroy_workqueue(fs_info->rmw_workers);
1785 	if (fs_info->compressed_write_workers)
1786 		destroy_workqueue(fs_info->compressed_write_workers);
1787 	btrfs_destroy_workqueue(fs_info->endio_write_workers);
1788 	btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
1789 	btrfs_destroy_workqueue(fs_info->delayed_workers);
1790 	btrfs_destroy_workqueue(fs_info->caching_workers);
1791 	btrfs_destroy_workqueue(fs_info->flush_workers);
1792 	btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
1793 	if (fs_info->discard_ctl.discard_workers)
1794 		destroy_workqueue(fs_info->discard_ctl.discard_workers);
1795 	/*
1796 	 * Now that all other work queues are destroyed, we can safely destroy
1797 	 * the queues used for metadata I/O, since tasks from those other work
1798 	 * queues can do metadata I/O operations.
1799 	 */
1800 	if (fs_info->endio_meta_workers)
1801 		destroy_workqueue(fs_info->endio_meta_workers);
1802 }
1803 
free_root_extent_buffers(struct btrfs_root * root)1804 static void free_root_extent_buffers(struct btrfs_root *root)
1805 {
1806 	if (root) {
1807 		free_extent_buffer(root->node);
1808 		free_extent_buffer(root->commit_root);
1809 		root->node = NULL;
1810 		root->commit_root = NULL;
1811 	}
1812 }
1813 
free_global_root_pointers(struct btrfs_fs_info * fs_info)1814 static void free_global_root_pointers(struct btrfs_fs_info *fs_info)
1815 {
1816 	struct btrfs_root *root, *tmp;
1817 
1818 	rbtree_postorder_for_each_entry_safe(root, tmp,
1819 					     &fs_info->global_root_tree,
1820 					     rb_node)
1821 		free_root_extent_buffers(root);
1822 }
1823 
1824 /* helper to cleanup tree roots */
free_root_pointers(struct btrfs_fs_info * info,bool free_chunk_root)1825 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
1826 {
1827 	free_root_extent_buffers(info->tree_root);
1828 
1829 	free_global_root_pointers(info);
1830 	free_root_extent_buffers(info->dev_root);
1831 	free_root_extent_buffers(info->quota_root);
1832 	free_root_extent_buffers(info->uuid_root);
1833 	free_root_extent_buffers(info->fs_root);
1834 	free_root_extent_buffers(info->data_reloc_root);
1835 	free_root_extent_buffers(info->block_group_root);
1836 	free_root_extent_buffers(info->stripe_root);
1837 	if (free_chunk_root)
1838 		free_root_extent_buffers(info->chunk_root);
1839 }
1840 
btrfs_put_root(struct btrfs_root * root)1841 void btrfs_put_root(struct btrfs_root *root)
1842 {
1843 	if (!root)
1844 		return;
1845 
1846 	if (refcount_dec_and_test(&root->refs)) {
1847 		if (WARN_ON(!xa_empty(&root->inodes)))
1848 			xa_destroy(&root->inodes);
1849 		WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
1850 		if (root->anon_dev)
1851 			free_anon_bdev(root->anon_dev);
1852 		free_root_extent_buffers(root);
1853 #ifdef CONFIG_BTRFS_DEBUG
1854 		spin_lock(&root->fs_info->fs_roots_radix_lock);
1855 		list_del_init(&root->leak_list);
1856 		spin_unlock(&root->fs_info->fs_roots_radix_lock);
1857 #endif
1858 		kfree(root);
1859 	}
1860 }
1861 
btrfs_free_fs_roots(struct btrfs_fs_info * fs_info)1862 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
1863 {
1864 	int ret;
1865 	struct btrfs_root *gang[8];
1866 	int i;
1867 
1868 	while (!list_empty(&fs_info->dead_roots)) {
1869 		gang[0] = list_entry(fs_info->dead_roots.next,
1870 				     struct btrfs_root, root_list);
1871 		list_del(&gang[0]->root_list);
1872 
1873 		if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
1874 			btrfs_drop_and_free_fs_root(fs_info, gang[0]);
1875 		btrfs_put_root(gang[0]);
1876 	}
1877 
1878 	while (1) {
1879 		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1880 					     (void **)gang, 0,
1881 					     ARRAY_SIZE(gang));
1882 		if (!ret)
1883 			break;
1884 		for (i = 0; i < ret; i++)
1885 			btrfs_drop_and_free_fs_root(fs_info, gang[i]);
1886 	}
1887 }
1888 
btrfs_init_scrub(struct btrfs_fs_info * fs_info)1889 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
1890 {
1891 	mutex_init(&fs_info->scrub_lock);
1892 	atomic_set(&fs_info->scrubs_running, 0);
1893 	atomic_set(&fs_info->scrub_pause_req, 0);
1894 	atomic_set(&fs_info->scrubs_paused, 0);
1895 	atomic_set(&fs_info->scrub_cancel_req, 0);
1896 	init_waitqueue_head(&fs_info->scrub_pause_wait);
1897 	refcount_set(&fs_info->scrub_workers_refcnt, 0);
1898 }
1899 
btrfs_init_balance(struct btrfs_fs_info * fs_info)1900 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
1901 {
1902 	spin_lock_init(&fs_info->balance_lock);
1903 	mutex_init(&fs_info->balance_mutex);
1904 	atomic_set(&fs_info->balance_pause_req, 0);
1905 	atomic_set(&fs_info->balance_cancel_req, 0);
1906 	fs_info->balance_ctl = NULL;
1907 	init_waitqueue_head(&fs_info->balance_wait_q);
1908 	atomic_set(&fs_info->reloc_cancel_req, 0);
1909 }
1910 
btrfs_init_btree_inode(struct super_block * sb)1911 static int btrfs_init_btree_inode(struct super_block *sb)
1912 {
1913 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1914 	unsigned long hash = btrfs_inode_hash(BTRFS_BTREE_INODE_OBJECTID,
1915 					      fs_info->tree_root);
1916 	struct inode *inode;
1917 
1918 	inode = new_inode(sb);
1919 	if (!inode)
1920 		return -ENOMEM;
1921 
1922 	btrfs_set_inode_number(BTRFS_I(inode), BTRFS_BTREE_INODE_OBJECTID);
1923 	set_nlink(inode, 1);
1924 	/*
1925 	 * we set the i_size on the btree inode to the max possible int.
1926 	 * the real end of the address space is determined by all of
1927 	 * the devices in the system
1928 	 */
1929 	inode->i_size = OFFSET_MAX;
1930 	inode->i_mapping->a_ops = &btree_aops;
1931 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
1932 
1933 	extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
1934 			    IO_TREE_BTREE_INODE_IO);
1935 	extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
1936 
1937 	BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
1938 	set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
1939 	__insert_inode_hash(inode, hash);
1940 	fs_info->btree_inode = inode;
1941 
1942 	return 0;
1943 }
1944 
btrfs_init_dev_replace_locks(struct btrfs_fs_info * fs_info)1945 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
1946 {
1947 	mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
1948 	init_rwsem(&fs_info->dev_replace.rwsem);
1949 	init_waitqueue_head(&fs_info->dev_replace.replace_wait);
1950 }
1951 
btrfs_init_qgroup(struct btrfs_fs_info * fs_info)1952 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
1953 {
1954 	spin_lock_init(&fs_info->qgroup_lock);
1955 	mutex_init(&fs_info->qgroup_ioctl_lock);
1956 	fs_info->qgroup_tree = RB_ROOT;
1957 	INIT_LIST_HEAD(&fs_info->dirty_qgroups);
1958 	fs_info->qgroup_seq = 1;
1959 	fs_info->qgroup_ulist = NULL;
1960 	fs_info->qgroup_rescan_running = false;
1961 	fs_info->qgroup_drop_subtree_thres = BTRFS_QGROUP_DROP_SUBTREE_THRES_DEFAULT;
1962 	mutex_init(&fs_info->qgroup_rescan_lock);
1963 }
1964 
btrfs_init_workqueues(struct btrfs_fs_info * fs_info)1965 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
1966 {
1967 	u32 max_active = fs_info->thread_pool_size;
1968 	unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
1969 	unsigned int ordered_flags = WQ_MEM_RECLAIM | WQ_FREEZABLE;
1970 
1971 	fs_info->workers =
1972 		btrfs_alloc_workqueue(fs_info, "worker", flags, max_active, 16);
1973 
1974 	fs_info->delalloc_workers =
1975 		btrfs_alloc_workqueue(fs_info, "delalloc",
1976 				      flags, max_active, 2);
1977 
1978 	fs_info->flush_workers =
1979 		btrfs_alloc_workqueue(fs_info, "flush_delalloc",
1980 				      flags, max_active, 0);
1981 
1982 	fs_info->caching_workers =
1983 		btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
1984 
1985 	fs_info->fixup_workers =
1986 		btrfs_alloc_ordered_workqueue(fs_info, "fixup", ordered_flags);
1987 
1988 	fs_info->endio_workers =
1989 		alloc_workqueue("btrfs-endio", flags, max_active);
1990 	fs_info->endio_meta_workers =
1991 		alloc_workqueue("btrfs-endio-meta", flags, max_active);
1992 	fs_info->rmw_workers = alloc_workqueue("btrfs-rmw", flags, max_active);
1993 	fs_info->endio_write_workers =
1994 		btrfs_alloc_workqueue(fs_info, "endio-write", flags,
1995 				      max_active, 2);
1996 	fs_info->compressed_write_workers =
1997 		alloc_workqueue("btrfs-compressed-write", flags, max_active);
1998 	fs_info->endio_freespace_worker =
1999 		btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2000 				      max_active, 0);
2001 	fs_info->delayed_workers =
2002 		btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2003 				      max_active, 0);
2004 	fs_info->qgroup_rescan_workers =
2005 		btrfs_alloc_ordered_workqueue(fs_info, "qgroup-rescan",
2006 					      ordered_flags);
2007 	fs_info->discard_ctl.discard_workers =
2008 		alloc_ordered_workqueue("btrfs_discard", WQ_FREEZABLE);
2009 
2010 	if (!(fs_info->workers &&
2011 	      fs_info->delalloc_workers && fs_info->flush_workers &&
2012 	      fs_info->endio_workers && fs_info->endio_meta_workers &&
2013 	      fs_info->compressed_write_workers &&
2014 	      fs_info->endio_write_workers &&
2015 	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2016 	      fs_info->caching_workers && fs_info->fixup_workers &&
2017 	      fs_info->delayed_workers && fs_info->qgroup_rescan_workers &&
2018 	      fs_info->discard_ctl.discard_workers)) {
2019 		return -ENOMEM;
2020 	}
2021 
2022 	return 0;
2023 }
2024 
btrfs_init_csum_hash(struct btrfs_fs_info * fs_info,u16 csum_type)2025 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2026 {
2027 	struct crypto_shash *csum_shash;
2028 	const char *csum_driver = btrfs_super_csum_driver(csum_type);
2029 
2030 	csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2031 
2032 	if (IS_ERR(csum_shash)) {
2033 		btrfs_err(fs_info, "error allocating %s hash for checksum",
2034 			  csum_driver);
2035 		return PTR_ERR(csum_shash);
2036 	}
2037 
2038 	fs_info->csum_shash = csum_shash;
2039 
2040 	/*
2041 	 * Check if the checksum implementation is a fast accelerated one.
2042 	 * As-is this is a bit of a hack and should be replaced once the csum
2043 	 * implementations provide that information themselves.
2044 	 */
2045 	switch (csum_type) {
2046 	case BTRFS_CSUM_TYPE_CRC32:
2047 		if (!strstr(crypto_shash_driver_name(csum_shash), "generic"))
2048 			set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
2049 		break;
2050 	case BTRFS_CSUM_TYPE_XXHASH:
2051 		set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
2052 		break;
2053 	default:
2054 		break;
2055 	}
2056 
2057 	btrfs_info(fs_info, "using %s (%s) checksum algorithm",
2058 			btrfs_super_csum_name(csum_type),
2059 			crypto_shash_driver_name(csum_shash));
2060 	return 0;
2061 }
2062 
btrfs_replay_log(struct btrfs_fs_info * fs_info,struct btrfs_fs_devices * fs_devices)2063 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2064 			    struct btrfs_fs_devices *fs_devices)
2065 {
2066 	int ret;
2067 	struct btrfs_tree_parent_check check = { 0 };
2068 	struct btrfs_root *log_tree_root;
2069 	struct btrfs_super_block *disk_super = fs_info->super_copy;
2070 	u64 bytenr = btrfs_super_log_root(disk_super);
2071 	int level = btrfs_super_log_root_level(disk_super);
2072 
2073 	if (fs_devices->rw_devices == 0) {
2074 		btrfs_warn(fs_info, "log replay required on RO media");
2075 		return -EIO;
2076 	}
2077 
2078 	log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2079 					 GFP_KERNEL);
2080 	if (!log_tree_root)
2081 		return -ENOMEM;
2082 
2083 	check.level = level;
2084 	check.transid = fs_info->generation + 1;
2085 	check.owner_root = BTRFS_TREE_LOG_OBJECTID;
2086 	log_tree_root->node = read_tree_block(fs_info, bytenr, &check);
2087 	if (IS_ERR(log_tree_root->node)) {
2088 		btrfs_warn(fs_info, "failed to read log tree");
2089 		ret = PTR_ERR(log_tree_root->node);
2090 		log_tree_root->node = NULL;
2091 		btrfs_put_root(log_tree_root);
2092 		return ret;
2093 	}
2094 	if (!extent_buffer_uptodate(log_tree_root->node)) {
2095 		btrfs_err(fs_info, "failed to read log tree");
2096 		btrfs_put_root(log_tree_root);
2097 		return -EIO;
2098 	}
2099 
2100 	/* returns with log_tree_root freed on success */
2101 	ret = btrfs_recover_log_trees(log_tree_root);
2102 	if (ret) {
2103 		btrfs_handle_fs_error(fs_info, ret,
2104 				      "Failed to recover log tree");
2105 		btrfs_put_root(log_tree_root);
2106 		return ret;
2107 	}
2108 
2109 	if (sb_rdonly(fs_info->sb)) {
2110 		ret = btrfs_commit_super(fs_info);
2111 		if (ret)
2112 			return ret;
2113 	}
2114 
2115 	return 0;
2116 }
2117 
load_global_roots_objectid(struct btrfs_root * tree_root,struct btrfs_path * path,u64 objectid,const char * name)2118 static int load_global_roots_objectid(struct btrfs_root *tree_root,
2119 				      struct btrfs_path *path, u64 objectid,
2120 				      const char *name)
2121 {
2122 	struct btrfs_fs_info *fs_info = tree_root->fs_info;
2123 	struct btrfs_root *root;
2124 	u64 max_global_id = 0;
2125 	int ret;
2126 	struct btrfs_key key = {
2127 		.objectid = objectid,
2128 		.type = BTRFS_ROOT_ITEM_KEY,
2129 		.offset = 0,
2130 	};
2131 	bool found = false;
2132 
2133 	/* If we have IGNOREDATACSUMS skip loading these roots. */
2134 	if (objectid == BTRFS_CSUM_TREE_OBJECTID &&
2135 	    btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2136 		set_bit(BTRFS_FS_STATE_NO_DATA_CSUMS, &fs_info->fs_state);
2137 		return 0;
2138 	}
2139 
2140 	while (1) {
2141 		ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2142 		if (ret < 0)
2143 			break;
2144 
2145 		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2146 			ret = btrfs_next_leaf(tree_root, path);
2147 			if (ret) {
2148 				if (ret > 0)
2149 					ret = 0;
2150 				break;
2151 			}
2152 		}
2153 		ret = 0;
2154 
2155 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2156 		if (key.objectid != objectid)
2157 			break;
2158 		btrfs_release_path(path);
2159 
2160 		/*
2161 		 * Just worry about this for extent tree, it'll be the same for
2162 		 * everybody.
2163 		 */
2164 		if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2165 			max_global_id = max(max_global_id, key.offset);
2166 
2167 		found = true;
2168 		root = read_tree_root_path(tree_root, path, &key);
2169 		if (IS_ERR(root)) {
2170 			if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2171 				ret = PTR_ERR(root);
2172 			break;
2173 		}
2174 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2175 		ret = btrfs_global_root_insert(root);
2176 		if (ret) {
2177 			btrfs_put_root(root);
2178 			break;
2179 		}
2180 		key.offset++;
2181 	}
2182 	btrfs_release_path(path);
2183 
2184 	if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2185 		fs_info->nr_global_roots = max_global_id + 1;
2186 
2187 	if (!found || ret) {
2188 		if (objectid == BTRFS_CSUM_TREE_OBJECTID)
2189 			set_bit(BTRFS_FS_STATE_NO_DATA_CSUMS, &fs_info->fs_state);
2190 
2191 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2192 			ret = ret ? ret : -ENOENT;
2193 		else
2194 			ret = 0;
2195 		btrfs_err(fs_info, "failed to load root %s", name);
2196 	}
2197 	return ret;
2198 }
2199 
load_global_roots(struct btrfs_root * tree_root)2200 static int load_global_roots(struct btrfs_root *tree_root)
2201 {
2202 	struct btrfs_path *path;
2203 	int ret = 0;
2204 
2205 	path = btrfs_alloc_path();
2206 	if (!path)
2207 		return -ENOMEM;
2208 
2209 	ret = load_global_roots_objectid(tree_root, path,
2210 					 BTRFS_EXTENT_TREE_OBJECTID, "extent");
2211 	if (ret)
2212 		goto out;
2213 	ret = load_global_roots_objectid(tree_root, path,
2214 					 BTRFS_CSUM_TREE_OBJECTID, "csum");
2215 	if (ret)
2216 		goto out;
2217 	if (!btrfs_fs_compat_ro(tree_root->fs_info, FREE_SPACE_TREE))
2218 		goto out;
2219 	ret = load_global_roots_objectid(tree_root, path,
2220 					 BTRFS_FREE_SPACE_TREE_OBJECTID,
2221 					 "free space");
2222 out:
2223 	btrfs_free_path(path);
2224 	return ret;
2225 }
2226 
btrfs_read_roots(struct btrfs_fs_info * fs_info)2227 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2228 {
2229 	struct btrfs_root *tree_root = fs_info->tree_root;
2230 	struct btrfs_root *root;
2231 	struct btrfs_key location;
2232 	int ret;
2233 
2234 	ASSERT(fs_info->tree_root);
2235 
2236 	ret = load_global_roots(tree_root);
2237 	if (ret)
2238 		return ret;
2239 
2240 	location.type = BTRFS_ROOT_ITEM_KEY;
2241 	location.offset = 0;
2242 
2243 	if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE)) {
2244 		location.objectid = BTRFS_BLOCK_GROUP_TREE_OBJECTID;
2245 		root = btrfs_read_tree_root(tree_root, &location);
2246 		if (IS_ERR(root)) {
2247 			if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2248 				ret = PTR_ERR(root);
2249 				goto out;
2250 			}
2251 		} else {
2252 			set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2253 			fs_info->block_group_root = root;
2254 		}
2255 	}
2256 
2257 	location.objectid = BTRFS_DEV_TREE_OBJECTID;
2258 	root = btrfs_read_tree_root(tree_root, &location);
2259 	if (IS_ERR(root)) {
2260 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2261 			ret = PTR_ERR(root);
2262 			goto out;
2263 		}
2264 	} else {
2265 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2266 		fs_info->dev_root = root;
2267 	}
2268 	/* Initialize fs_info for all devices in any case */
2269 	ret = btrfs_init_devices_late(fs_info);
2270 	if (ret)
2271 		goto out;
2272 
2273 	/*
2274 	 * This tree can share blocks with some other fs tree during relocation
2275 	 * and we need a proper setup by btrfs_get_fs_root
2276 	 */
2277 	root = btrfs_get_fs_root(tree_root->fs_info,
2278 				 BTRFS_DATA_RELOC_TREE_OBJECTID, true);
2279 	if (IS_ERR(root)) {
2280 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2281 			ret = PTR_ERR(root);
2282 			goto out;
2283 		}
2284 	} else {
2285 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2286 		fs_info->data_reloc_root = root;
2287 	}
2288 
2289 	location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2290 	root = btrfs_read_tree_root(tree_root, &location);
2291 	if (!IS_ERR(root)) {
2292 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2293 		fs_info->quota_root = root;
2294 	}
2295 
2296 	location.objectid = BTRFS_UUID_TREE_OBJECTID;
2297 	root = btrfs_read_tree_root(tree_root, &location);
2298 	if (IS_ERR(root)) {
2299 		if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2300 			ret = PTR_ERR(root);
2301 			if (ret != -ENOENT)
2302 				goto out;
2303 		}
2304 	} else {
2305 		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2306 		fs_info->uuid_root = root;
2307 	}
2308 
2309 	if (btrfs_fs_incompat(fs_info, RAID_STRIPE_TREE)) {
2310 		location.objectid = BTRFS_RAID_STRIPE_TREE_OBJECTID;
2311 		root = btrfs_read_tree_root(tree_root, &location);
2312 		if (IS_ERR(root)) {
2313 			if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2314 				ret = PTR_ERR(root);
2315 				goto out;
2316 			}
2317 		} else {
2318 			set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2319 			fs_info->stripe_root = root;
2320 		}
2321 	}
2322 
2323 	return 0;
2324 out:
2325 	btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2326 		   location.objectid, ret);
2327 	return ret;
2328 }
2329 
2330 /*
2331  * Real super block validation
2332  * NOTE: super csum type and incompat features will not be checked here.
2333  *
2334  * @sb:		super block to check
2335  * @mirror_num:	the super block number to check its bytenr:
2336  * 		0	the primary (1st) sb
2337  * 		1, 2	2nd and 3rd backup copy
2338  * 	       -1	skip bytenr check
2339  */
btrfs_validate_super(const struct btrfs_fs_info * fs_info,const struct btrfs_super_block * sb,int mirror_num)2340 int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
2341 			 const struct btrfs_super_block *sb, int mirror_num)
2342 {
2343 	u64 nodesize = btrfs_super_nodesize(sb);
2344 	u64 sectorsize = btrfs_super_sectorsize(sb);
2345 	int ret = 0;
2346 	const bool ignore_flags = btrfs_test_opt(fs_info, IGNORESUPERFLAGS);
2347 
2348 	if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2349 		btrfs_err(fs_info, "no valid FS found");
2350 		ret = -EINVAL;
2351 	}
2352 	if ((btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP)) {
2353 		if (!ignore_flags) {
2354 			btrfs_err(fs_info,
2355 			"unrecognized or unsupported super flag 0x%llx",
2356 				  btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2357 			ret = -EINVAL;
2358 		} else {
2359 			btrfs_info(fs_info,
2360 			"unrecognized or unsupported super flags: 0x%llx, ignored",
2361 				   btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2362 		}
2363 	}
2364 	if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2365 		btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2366 				btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2367 		ret = -EINVAL;
2368 	}
2369 	if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2370 		btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2371 				btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2372 		ret = -EINVAL;
2373 	}
2374 	if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2375 		btrfs_err(fs_info, "log_root level too big: %d >= %d",
2376 				btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2377 		ret = -EINVAL;
2378 	}
2379 
2380 	/*
2381 	 * Check sectorsize and nodesize first, other check will need it.
2382 	 * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2383 	 */
2384 	if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2385 	    sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2386 		btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2387 		ret = -EINVAL;
2388 	}
2389 
2390 	/*
2391 	 * We only support at most two sectorsizes: 4K and PAGE_SIZE.
2392 	 *
2393 	 * We can support 16K sectorsize with 64K page size without problem,
2394 	 * but such sectorsize/pagesize combination doesn't make much sense.
2395 	 * 4K will be our future standard, PAGE_SIZE is supported from the very
2396 	 * beginning.
2397 	 */
2398 	if (sectorsize > PAGE_SIZE || (sectorsize != SZ_4K && sectorsize != PAGE_SIZE)) {
2399 		btrfs_err(fs_info,
2400 			"sectorsize %llu not yet supported for page size %lu",
2401 			sectorsize, PAGE_SIZE);
2402 		ret = -EINVAL;
2403 	}
2404 
2405 	if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2406 	    nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2407 		btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2408 		ret = -EINVAL;
2409 	}
2410 	if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2411 		btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2412 			  le32_to_cpu(sb->__unused_leafsize), nodesize);
2413 		ret = -EINVAL;
2414 	}
2415 
2416 	/* Root alignment check */
2417 	if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2418 		btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2419 			   btrfs_super_root(sb));
2420 		ret = -EINVAL;
2421 	}
2422 	if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2423 		btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2424 			   btrfs_super_chunk_root(sb));
2425 		ret = -EINVAL;
2426 	}
2427 	if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2428 		btrfs_warn(fs_info, "log_root block unaligned: %llu",
2429 			   btrfs_super_log_root(sb));
2430 		ret = -EINVAL;
2431 	}
2432 
2433 	if (!fs_info->fs_devices->temp_fsid &&
2434 	    memcmp(fs_info->fs_devices->fsid, sb->fsid, BTRFS_FSID_SIZE) != 0) {
2435 		btrfs_err(fs_info,
2436 		"superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
2437 			  sb->fsid, fs_info->fs_devices->fsid);
2438 		ret = -EINVAL;
2439 	}
2440 
2441 	if (memcmp(fs_info->fs_devices->metadata_uuid, btrfs_sb_fsid_ptr(sb),
2442 		   BTRFS_FSID_SIZE) != 0) {
2443 		btrfs_err(fs_info,
2444 "superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
2445 			  btrfs_sb_fsid_ptr(sb), fs_info->fs_devices->metadata_uuid);
2446 		ret = -EINVAL;
2447 	}
2448 
2449 	if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2450 		   BTRFS_FSID_SIZE) != 0) {
2451 		btrfs_err(fs_info,
2452 			"dev_item UUID does not match metadata fsid: %pU != %pU",
2453 			fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2454 		ret = -EINVAL;
2455 	}
2456 
2457 	/*
2458 	 * Artificial requirement for block-group-tree to force newer features
2459 	 * (free-space-tree, no-holes) so the test matrix is smaller.
2460 	 */
2461 	if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) &&
2462 	    (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID) ||
2463 	     !btrfs_fs_incompat(fs_info, NO_HOLES))) {
2464 		btrfs_err(fs_info,
2465 		"block-group-tree feature requires free-space-tree and no-holes");
2466 		ret = -EINVAL;
2467 	}
2468 
2469 	/*
2470 	 * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2471 	 * done later
2472 	 */
2473 	if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2474 		btrfs_err(fs_info, "bytes_used is too small %llu",
2475 			  btrfs_super_bytes_used(sb));
2476 		ret = -EINVAL;
2477 	}
2478 	if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2479 		btrfs_err(fs_info, "invalid stripesize %u",
2480 			  btrfs_super_stripesize(sb));
2481 		ret = -EINVAL;
2482 	}
2483 	if (btrfs_super_num_devices(sb) > (1UL << 31))
2484 		btrfs_warn(fs_info, "suspicious number of devices: %llu",
2485 			   btrfs_super_num_devices(sb));
2486 	if (btrfs_super_num_devices(sb) == 0) {
2487 		btrfs_err(fs_info, "number of devices is 0");
2488 		ret = -EINVAL;
2489 	}
2490 
2491 	if (mirror_num >= 0 &&
2492 	    btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2493 		btrfs_err(fs_info, "super offset mismatch %llu != %u",
2494 			  btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2495 		ret = -EINVAL;
2496 	}
2497 
2498 	/*
2499 	 * Obvious sys_chunk_array corruptions, it must hold at least one key
2500 	 * and one chunk
2501 	 */
2502 	if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2503 		btrfs_err(fs_info, "system chunk array too big %u > %u",
2504 			  btrfs_super_sys_array_size(sb),
2505 			  BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2506 		ret = -EINVAL;
2507 	}
2508 	if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2509 			+ sizeof(struct btrfs_chunk)) {
2510 		btrfs_err(fs_info, "system chunk array too small %u < %zu",
2511 			  btrfs_super_sys_array_size(sb),
2512 			  sizeof(struct btrfs_disk_key)
2513 			  + sizeof(struct btrfs_chunk));
2514 		ret = -EINVAL;
2515 	}
2516 
2517 	/*
2518 	 * The generation is a global counter, we'll trust it more than the others
2519 	 * but it's still possible that it's the one that's wrong.
2520 	 */
2521 	if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2522 		btrfs_warn(fs_info,
2523 			"suspicious: generation < chunk_root_generation: %llu < %llu",
2524 			btrfs_super_generation(sb),
2525 			btrfs_super_chunk_root_generation(sb));
2526 	if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2527 	    && btrfs_super_cache_generation(sb) != (u64)-1)
2528 		btrfs_warn(fs_info,
2529 			"suspicious: generation < cache_generation: %llu < %llu",
2530 			btrfs_super_generation(sb),
2531 			btrfs_super_cache_generation(sb));
2532 
2533 	return ret;
2534 }
2535 
2536 /*
2537  * Validation of super block at mount time.
2538  * Some checks already done early at mount time, like csum type and incompat
2539  * flags will be skipped.
2540  */
btrfs_validate_mount_super(struct btrfs_fs_info * fs_info)2541 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2542 {
2543 	return btrfs_validate_super(fs_info, fs_info->super_copy, 0);
2544 }
2545 
2546 /*
2547  * Validation of super block at write time.
2548  * Some checks like bytenr check will be skipped as their values will be
2549  * overwritten soon.
2550  * Extra checks like csum type and incompat flags will be done here.
2551  */
btrfs_validate_write_super(struct btrfs_fs_info * fs_info,struct btrfs_super_block * sb)2552 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2553 				      struct btrfs_super_block *sb)
2554 {
2555 	int ret;
2556 
2557 	ret = btrfs_validate_super(fs_info, sb, -1);
2558 	if (ret < 0)
2559 		goto out;
2560 	if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2561 		ret = -EUCLEAN;
2562 		btrfs_err(fs_info, "invalid csum type, has %u want %u",
2563 			  btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2564 		goto out;
2565 	}
2566 	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2567 		ret = -EUCLEAN;
2568 		btrfs_err(fs_info,
2569 		"invalid incompat flags, has 0x%llx valid mask 0x%llx",
2570 			  btrfs_super_incompat_flags(sb),
2571 			  (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2572 		goto out;
2573 	}
2574 out:
2575 	if (ret < 0)
2576 		btrfs_err(fs_info,
2577 		"super block corruption detected before writing it to disk");
2578 	return ret;
2579 }
2580 
load_super_root(struct btrfs_root * root,u64 bytenr,u64 gen,int level)2581 static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int level)
2582 {
2583 	struct btrfs_tree_parent_check check = {
2584 		.level = level,
2585 		.transid = gen,
2586 		.owner_root = btrfs_root_id(root)
2587 	};
2588 	int ret = 0;
2589 
2590 	root->node = read_tree_block(root->fs_info, bytenr, &check);
2591 	if (IS_ERR(root->node)) {
2592 		ret = PTR_ERR(root->node);
2593 		root->node = NULL;
2594 		return ret;
2595 	}
2596 	if (!extent_buffer_uptodate(root->node)) {
2597 		free_extent_buffer(root->node);
2598 		root->node = NULL;
2599 		return -EIO;
2600 	}
2601 
2602 	btrfs_set_root_node(&root->root_item, root->node);
2603 	root->commit_root = btrfs_root_node(root);
2604 	btrfs_set_root_refs(&root->root_item, 1);
2605 	return ret;
2606 }
2607 
load_important_roots(struct btrfs_fs_info * fs_info)2608 static int load_important_roots(struct btrfs_fs_info *fs_info)
2609 {
2610 	struct btrfs_super_block *sb = fs_info->super_copy;
2611 	u64 gen, bytenr;
2612 	int level, ret;
2613 
2614 	bytenr = btrfs_super_root(sb);
2615 	gen = btrfs_super_generation(sb);
2616 	level = btrfs_super_root_level(sb);
2617 	ret = load_super_root(fs_info->tree_root, bytenr, gen, level);
2618 	if (ret) {
2619 		btrfs_warn(fs_info, "couldn't read tree root");
2620 		return ret;
2621 	}
2622 	return 0;
2623 }
2624 
init_tree_roots(struct btrfs_fs_info * fs_info)2625 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2626 {
2627 	int backup_index = find_newest_super_backup(fs_info);
2628 	struct btrfs_super_block *sb = fs_info->super_copy;
2629 	struct btrfs_root *tree_root = fs_info->tree_root;
2630 	bool handle_error = false;
2631 	int ret = 0;
2632 	int i;
2633 
2634 	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2635 		if (handle_error) {
2636 			if (!IS_ERR(tree_root->node))
2637 				free_extent_buffer(tree_root->node);
2638 			tree_root->node = NULL;
2639 
2640 			if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2641 				break;
2642 
2643 			free_root_pointers(fs_info, 0);
2644 
2645 			/*
2646 			 * Don't use the log in recovery mode, it won't be
2647 			 * valid
2648 			 */
2649 			btrfs_set_super_log_root(sb, 0);
2650 
2651 			btrfs_warn(fs_info, "try to load backup roots slot %d", i);
2652 			ret = read_backup_root(fs_info, i);
2653 			backup_index = ret;
2654 			if (ret < 0)
2655 				return ret;
2656 		}
2657 
2658 		ret = load_important_roots(fs_info);
2659 		if (ret) {
2660 			handle_error = true;
2661 			continue;
2662 		}
2663 
2664 		/*
2665 		 * No need to hold btrfs_root::objectid_mutex since the fs
2666 		 * hasn't been fully initialised and we are the only user
2667 		 */
2668 		ret = btrfs_init_root_free_objectid(tree_root);
2669 		if (ret < 0) {
2670 			handle_error = true;
2671 			continue;
2672 		}
2673 
2674 		ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
2675 
2676 		ret = btrfs_read_roots(fs_info);
2677 		if (ret < 0) {
2678 			handle_error = true;
2679 			continue;
2680 		}
2681 
2682 		/* All successful */
2683 		fs_info->generation = btrfs_header_generation(tree_root->node);
2684 		btrfs_set_last_trans_committed(fs_info, fs_info->generation);
2685 		fs_info->last_reloc_trans = 0;
2686 
2687 		/* Always begin writing backup roots after the one being used */
2688 		if (backup_index < 0) {
2689 			fs_info->backup_root_index = 0;
2690 		} else {
2691 			fs_info->backup_root_index = backup_index + 1;
2692 			fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
2693 		}
2694 		break;
2695 	}
2696 
2697 	return ret;
2698 }
2699 
btrfs_init_fs_info(struct btrfs_fs_info * fs_info)2700 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
2701 {
2702 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2703 	INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2704 	INIT_LIST_HEAD(&fs_info->trans_list);
2705 	INIT_LIST_HEAD(&fs_info->dead_roots);
2706 	INIT_LIST_HEAD(&fs_info->delayed_iputs);
2707 	INIT_LIST_HEAD(&fs_info->delalloc_roots);
2708 	INIT_LIST_HEAD(&fs_info->caching_block_groups);
2709 	spin_lock_init(&fs_info->delalloc_root_lock);
2710 	spin_lock_init(&fs_info->trans_lock);
2711 	spin_lock_init(&fs_info->fs_roots_radix_lock);
2712 	spin_lock_init(&fs_info->delayed_iput_lock);
2713 	spin_lock_init(&fs_info->defrag_inodes_lock);
2714 	spin_lock_init(&fs_info->super_lock);
2715 	spin_lock_init(&fs_info->buffer_lock);
2716 	spin_lock_init(&fs_info->unused_bgs_lock);
2717 	spin_lock_init(&fs_info->treelog_bg_lock);
2718 	spin_lock_init(&fs_info->zone_active_bgs_lock);
2719 	spin_lock_init(&fs_info->relocation_bg_lock);
2720 	rwlock_init(&fs_info->tree_mod_log_lock);
2721 	rwlock_init(&fs_info->global_root_lock);
2722 	mutex_init(&fs_info->unused_bg_unpin_mutex);
2723 	mutex_init(&fs_info->reclaim_bgs_lock);
2724 	mutex_init(&fs_info->reloc_mutex);
2725 	mutex_init(&fs_info->delalloc_root_mutex);
2726 	mutex_init(&fs_info->zoned_meta_io_lock);
2727 	mutex_init(&fs_info->zoned_data_reloc_io_lock);
2728 	seqlock_init(&fs_info->profiles_lock);
2729 
2730 	btrfs_lockdep_init_map(fs_info, btrfs_trans_num_writers);
2731 	btrfs_lockdep_init_map(fs_info, btrfs_trans_num_extwriters);
2732 	btrfs_lockdep_init_map(fs_info, btrfs_trans_pending_ordered);
2733 	btrfs_lockdep_init_map(fs_info, btrfs_ordered_extent);
2734 	btrfs_state_lockdep_init_map(fs_info, btrfs_trans_commit_prep,
2735 				     BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
2736 	btrfs_state_lockdep_init_map(fs_info, btrfs_trans_unblocked,
2737 				     BTRFS_LOCKDEP_TRANS_UNBLOCKED);
2738 	btrfs_state_lockdep_init_map(fs_info, btrfs_trans_super_committed,
2739 				     BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED);
2740 	btrfs_state_lockdep_init_map(fs_info, btrfs_trans_completed,
2741 				     BTRFS_LOCKDEP_TRANS_COMPLETED);
2742 
2743 	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2744 	INIT_LIST_HEAD(&fs_info->space_info);
2745 	INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2746 	INIT_LIST_HEAD(&fs_info->unused_bgs);
2747 	INIT_LIST_HEAD(&fs_info->reclaim_bgs);
2748 	INIT_LIST_HEAD(&fs_info->zone_active_bgs);
2749 #ifdef CONFIG_BTRFS_DEBUG
2750 	INIT_LIST_HEAD(&fs_info->allocated_roots);
2751 	INIT_LIST_HEAD(&fs_info->allocated_ebs);
2752 	spin_lock_init(&fs_info->eb_leak_lock);
2753 #endif
2754 	fs_info->mapping_tree = RB_ROOT_CACHED;
2755 	rwlock_init(&fs_info->mapping_tree_lock);
2756 	btrfs_init_block_rsv(&fs_info->global_block_rsv,
2757 			     BTRFS_BLOCK_RSV_GLOBAL);
2758 	btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2759 	btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2760 	btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2761 	btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2762 			     BTRFS_BLOCK_RSV_DELOPS);
2763 	btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
2764 			     BTRFS_BLOCK_RSV_DELREFS);
2765 
2766 	atomic_set(&fs_info->async_delalloc_pages, 0);
2767 	atomic_set(&fs_info->defrag_running, 0);
2768 	atomic_set(&fs_info->nr_delayed_iputs, 0);
2769 	atomic64_set(&fs_info->tree_mod_seq, 0);
2770 	fs_info->global_root_tree = RB_ROOT;
2771 	fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2772 	fs_info->metadata_ratio = 0;
2773 	fs_info->defrag_inodes = RB_ROOT;
2774 	atomic64_set(&fs_info->free_chunk_space, 0);
2775 	fs_info->tree_mod_log = RB_ROOT;
2776 	fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2777 	btrfs_init_ref_verify(fs_info);
2778 
2779 	fs_info->thread_pool_size = min_t(unsigned long,
2780 					  num_online_cpus() + 2, 8);
2781 
2782 	INIT_LIST_HEAD(&fs_info->ordered_roots);
2783 	spin_lock_init(&fs_info->ordered_root_lock);
2784 
2785 	btrfs_init_scrub(fs_info);
2786 	btrfs_init_balance(fs_info);
2787 	btrfs_init_async_reclaim_work(fs_info);
2788 	btrfs_init_extent_map_shrinker_work(fs_info);
2789 
2790 	rwlock_init(&fs_info->block_group_cache_lock);
2791 	fs_info->block_group_cache_tree = RB_ROOT_CACHED;
2792 
2793 	extent_io_tree_init(fs_info, &fs_info->excluded_extents,
2794 			    IO_TREE_FS_EXCLUDED_EXTENTS);
2795 
2796 	mutex_init(&fs_info->ordered_operations_mutex);
2797 	mutex_init(&fs_info->tree_log_mutex);
2798 	mutex_init(&fs_info->chunk_mutex);
2799 	mutex_init(&fs_info->transaction_kthread_mutex);
2800 	mutex_init(&fs_info->cleaner_mutex);
2801 	mutex_init(&fs_info->ro_block_group_mutex);
2802 	init_rwsem(&fs_info->commit_root_sem);
2803 	init_rwsem(&fs_info->cleanup_work_sem);
2804 	init_rwsem(&fs_info->subvol_sem);
2805 	sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2806 
2807 	btrfs_init_dev_replace_locks(fs_info);
2808 	btrfs_init_qgroup(fs_info);
2809 	btrfs_discard_init(fs_info);
2810 
2811 	btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2812 	btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2813 
2814 	init_waitqueue_head(&fs_info->transaction_throttle);
2815 	init_waitqueue_head(&fs_info->transaction_wait);
2816 	init_waitqueue_head(&fs_info->transaction_blocked_wait);
2817 	init_waitqueue_head(&fs_info->async_submit_wait);
2818 	init_waitqueue_head(&fs_info->delayed_iputs_wait);
2819 
2820 	/* Usable values until the real ones are cached from the superblock */
2821 	fs_info->nodesize = 4096;
2822 	fs_info->sectorsize = 4096;
2823 	fs_info->sectorsize_bits = ilog2(4096);
2824 	fs_info->stripesize = 4096;
2825 
2826 	/* Default compress algorithm when user does -o compress */
2827 	fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2828 
2829 	fs_info->max_extent_size = BTRFS_MAX_EXTENT_SIZE;
2830 
2831 	spin_lock_init(&fs_info->swapfile_pins_lock);
2832 	fs_info->swapfile_pins = RB_ROOT;
2833 
2834 	fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH;
2835 	INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work);
2836 }
2837 
init_mount_fs_info(struct btrfs_fs_info * fs_info,struct super_block * sb)2838 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
2839 {
2840 	int ret;
2841 
2842 	fs_info->sb = sb;
2843 	/* Temporary fixed values for block size until we read the superblock. */
2844 	sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
2845 	sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
2846 
2847 	ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
2848 	if (ret)
2849 		return ret;
2850 
2851 	ret = percpu_counter_init(&fs_info->evictable_extent_maps, 0, GFP_KERNEL);
2852 	if (ret)
2853 		return ret;
2854 
2855 	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2856 	if (ret)
2857 		return ret;
2858 
2859 	fs_info->dirty_metadata_batch = PAGE_SIZE *
2860 					(1 + ilog2(nr_cpu_ids));
2861 
2862 	ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2863 	if (ret)
2864 		return ret;
2865 
2866 	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
2867 			GFP_KERNEL);
2868 	if (ret)
2869 		return ret;
2870 
2871 	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2872 					GFP_KERNEL);
2873 	if (!fs_info->delayed_root)
2874 		return -ENOMEM;
2875 	btrfs_init_delayed_root(fs_info->delayed_root);
2876 
2877 	if (sb_rdonly(sb))
2878 		set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
2879 	if (btrfs_test_opt(fs_info, IGNOREMETACSUMS))
2880 		set_bit(BTRFS_FS_STATE_SKIP_META_CSUMS, &fs_info->fs_state);
2881 
2882 	return btrfs_alloc_stripe_hash_table(fs_info);
2883 }
2884 
btrfs_uuid_rescan_kthread(void * data)2885 static int btrfs_uuid_rescan_kthread(void *data)
2886 {
2887 	struct btrfs_fs_info *fs_info = data;
2888 	int ret;
2889 
2890 	/*
2891 	 * 1st step is to iterate through the existing UUID tree and
2892 	 * to delete all entries that contain outdated data.
2893 	 * 2nd step is to add all missing entries to the UUID tree.
2894 	 */
2895 	ret = btrfs_uuid_tree_iterate(fs_info);
2896 	if (ret < 0) {
2897 		if (ret != -EINTR)
2898 			btrfs_warn(fs_info, "iterating uuid_tree failed %d",
2899 				   ret);
2900 		up(&fs_info->uuid_tree_rescan_sem);
2901 		return ret;
2902 	}
2903 	return btrfs_uuid_scan_kthread(data);
2904 }
2905 
btrfs_check_uuid_tree(struct btrfs_fs_info * fs_info)2906 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
2907 {
2908 	struct task_struct *task;
2909 
2910 	down(&fs_info->uuid_tree_rescan_sem);
2911 	task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
2912 	if (IS_ERR(task)) {
2913 		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
2914 		btrfs_warn(fs_info, "failed to start uuid_rescan task");
2915 		up(&fs_info->uuid_tree_rescan_sem);
2916 		return PTR_ERR(task);
2917 	}
2918 
2919 	return 0;
2920 }
2921 
btrfs_cleanup_fs_roots(struct btrfs_fs_info * fs_info)2922 static int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2923 {
2924 	u64 root_objectid = 0;
2925 	struct btrfs_root *gang[8];
2926 	int ret = 0;
2927 
2928 	while (1) {
2929 		unsigned int found;
2930 
2931 		spin_lock(&fs_info->fs_roots_radix_lock);
2932 		found = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2933 					     (void **)gang, root_objectid,
2934 					     ARRAY_SIZE(gang));
2935 		if (!found) {
2936 			spin_unlock(&fs_info->fs_roots_radix_lock);
2937 			break;
2938 		}
2939 		root_objectid = btrfs_root_id(gang[found - 1]) + 1;
2940 
2941 		for (int i = 0; i < found; i++) {
2942 			/* Avoid to grab roots in dead_roots. */
2943 			if (btrfs_root_refs(&gang[i]->root_item) == 0) {
2944 				gang[i] = NULL;
2945 				continue;
2946 			}
2947 			/* Grab all the search result for later use. */
2948 			gang[i] = btrfs_grab_root(gang[i]);
2949 		}
2950 		spin_unlock(&fs_info->fs_roots_radix_lock);
2951 
2952 		for (int i = 0; i < found; i++) {
2953 			if (!gang[i])
2954 				continue;
2955 			root_objectid = btrfs_root_id(gang[i]);
2956 			/*
2957 			 * Continue to release the remaining roots after the first
2958 			 * error without cleanup and preserve the first error
2959 			 * for the return.
2960 			 */
2961 			if (!ret)
2962 				ret = btrfs_orphan_cleanup(gang[i]);
2963 			btrfs_put_root(gang[i]);
2964 		}
2965 		if (ret)
2966 			break;
2967 
2968 		root_objectid++;
2969 	}
2970 	return ret;
2971 }
2972 
2973 /*
2974  * Mounting logic specific to read-write file systems. Shared by open_ctree
2975  * and btrfs_remount when remounting from read-only to read-write.
2976  */
btrfs_start_pre_rw_mount(struct btrfs_fs_info * fs_info)2977 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
2978 {
2979 	int ret;
2980 	const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
2981 	bool rebuild_free_space_tree = false;
2982 
2983 	if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
2984 	    btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2985 		if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
2986 			btrfs_warn(fs_info,
2987 				   "'clear_cache' option is ignored with extent tree v2");
2988 		else
2989 			rebuild_free_space_tree = true;
2990 	} else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
2991 		   !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
2992 		btrfs_warn(fs_info, "free space tree is invalid");
2993 		rebuild_free_space_tree = true;
2994 	}
2995 
2996 	if (rebuild_free_space_tree) {
2997 		btrfs_info(fs_info, "rebuilding free space tree");
2998 		ret = btrfs_rebuild_free_space_tree(fs_info);
2999 		if (ret) {
3000 			btrfs_warn(fs_info,
3001 				   "failed to rebuild free space tree: %d", ret);
3002 			goto out;
3003 		}
3004 	}
3005 
3006 	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3007 	    !btrfs_test_opt(fs_info, FREE_SPACE_TREE)) {
3008 		btrfs_info(fs_info, "disabling free space tree");
3009 		ret = btrfs_delete_free_space_tree(fs_info);
3010 		if (ret) {
3011 			btrfs_warn(fs_info,
3012 				   "failed to disable free space tree: %d", ret);
3013 			goto out;
3014 		}
3015 	}
3016 
3017 	/*
3018 	 * btrfs_find_orphan_roots() is responsible for finding all the dead
3019 	 * roots (with 0 refs), flag them with BTRFS_ROOT_DEAD_TREE and load
3020 	 * them into the fs_info->fs_roots_radix tree. This must be done before
3021 	 * calling btrfs_orphan_cleanup() on the tree root. If we don't do it
3022 	 * first, then btrfs_orphan_cleanup() will delete a dead root's orphan
3023 	 * item before the root's tree is deleted - this means that if we unmount
3024 	 * or crash before the deletion completes, on the next mount we will not
3025 	 * delete what remains of the tree because the orphan item does not
3026 	 * exists anymore, which is what tells us we have a pending deletion.
3027 	 */
3028 	ret = btrfs_find_orphan_roots(fs_info);
3029 	if (ret)
3030 		goto out;
3031 
3032 	ret = btrfs_cleanup_fs_roots(fs_info);
3033 	if (ret)
3034 		goto out;
3035 
3036 	down_read(&fs_info->cleanup_work_sem);
3037 	if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3038 	    (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3039 		up_read(&fs_info->cleanup_work_sem);
3040 		goto out;
3041 	}
3042 	up_read(&fs_info->cleanup_work_sem);
3043 
3044 	mutex_lock(&fs_info->cleaner_mutex);
3045 	ret = btrfs_recover_relocation(fs_info);
3046 	mutex_unlock(&fs_info->cleaner_mutex);
3047 	if (ret < 0) {
3048 		btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
3049 		goto out;
3050 	}
3051 
3052 	if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3053 	    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3054 		btrfs_info(fs_info, "creating free space tree");
3055 		ret = btrfs_create_free_space_tree(fs_info);
3056 		if (ret) {
3057 			btrfs_warn(fs_info,
3058 				"failed to create free space tree: %d", ret);
3059 			goto out;
3060 		}
3061 	}
3062 
3063 	if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3064 		ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3065 		if (ret)
3066 			goto out;
3067 	}
3068 
3069 	ret = btrfs_resume_balance_async(fs_info);
3070 	if (ret)
3071 		goto out;
3072 
3073 	ret = btrfs_resume_dev_replace_async(fs_info);
3074 	if (ret) {
3075 		btrfs_warn(fs_info, "failed to resume dev_replace");
3076 		goto out;
3077 	}
3078 
3079 	btrfs_qgroup_rescan_resume(fs_info);
3080 
3081 	if (!fs_info->uuid_root) {
3082 		btrfs_info(fs_info, "creating UUID tree");
3083 		ret = btrfs_create_uuid_tree(fs_info);
3084 		if (ret) {
3085 			btrfs_warn(fs_info,
3086 				   "failed to create the UUID tree %d", ret);
3087 			goto out;
3088 		}
3089 	}
3090 
3091 out:
3092 	return ret;
3093 }
3094 
3095 /*
3096  * Do various sanity and dependency checks of different features.
3097  *
3098  * @is_rw_mount:	If the mount is read-write.
3099  *
3100  * This is the place for less strict checks (like for subpage or artificial
3101  * feature dependencies).
3102  *
3103  * For strict checks or possible corruption detection, see
3104  * btrfs_validate_super().
3105  *
3106  * This should be called after btrfs_parse_options(), as some mount options
3107  * (space cache related) can modify on-disk format like free space tree and
3108  * screw up certain feature dependencies.
3109  */
btrfs_check_features(struct btrfs_fs_info * fs_info,bool is_rw_mount)3110 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount)
3111 {
3112 	struct btrfs_super_block *disk_super = fs_info->super_copy;
3113 	u64 incompat = btrfs_super_incompat_flags(disk_super);
3114 	const u64 compat_ro = btrfs_super_compat_ro_flags(disk_super);
3115 	const u64 compat_ro_unsupp = (compat_ro & ~BTRFS_FEATURE_COMPAT_RO_SUPP);
3116 
3117 	if (incompat & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
3118 		btrfs_err(fs_info,
3119 		"cannot mount because of unknown incompat features (0x%llx)",
3120 		    incompat);
3121 		return -EINVAL;
3122 	}
3123 
3124 	/* Runtime limitation for mixed block groups. */
3125 	if ((incompat & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3126 	    (fs_info->sectorsize != fs_info->nodesize)) {
3127 		btrfs_err(fs_info,
3128 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3129 			fs_info->nodesize, fs_info->sectorsize);
3130 		return -EINVAL;
3131 	}
3132 
3133 	/* Mixed backref is an always-enabled feature. */
3134 	incompat |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3135 
3136 	/* Set compression related flags just in case. */
3137 	if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3138 		incompat |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3139 	else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3140 		incompat |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3141 
3142 	/*
3143 	 * An ancient flag, which should really be marked deprecated.
3144 	 * Such runtime limitation doesn't really need a incompat flag.
3145 	 */
3146 	if (btrfs_super_nodesize(disk_super) > PAGE_SIZE)
3147 		incompat |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3148 
3149 	if (compat_ro_unsupp && is_rw_mount) {
3150 		btrfs_err(fs_info,
3151 	"cannot mount read-write because of unknown compat_ro features (0x%llx)",
3152 		       compat_ro);
3153 		return -EINVAL;
3154 	}
3155 
3156 	/*
3157 	 * We have unsupported RO compat features, although RO mounted, we
3158 	 * should not cause any metadata writes, including log replay.
3159 	 * Or we could screw up whatever the new feature requires.
3160 	 */
3161 	if (compat_ro_unsupp && btrfs_super_log_root(disk_super) &&
3162 	    !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3163 		btrfs_err(fs_info,
3164 "cannot replay dirty log with unsupported compat_ro features (0x%llx), try rescue=nologreplay",
3165 			  compat_ro);
3166 		return -EINVAL;
3167 	}
3168 
3169 	/*
3170 	 * Artificial limitations for block group tree, to force
3171 	 * block-group-tree to rely on no-holes and free-space-tree.
3172 	 */
3173 	if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) &&
3174 	    (!btrfs_fs_incompat(fs_info, NO_HOLES) ||
3175 	     !btrfs_test_opt(fs_info, FREE_SPACE_TREE))) {
3176 		btrfs_err(fs_info,
3177 "block-group-tree feature requires no-holes and free-space-tree features");
3178 		return -EINVAL;
3179 	}
3180 
3181 	/*
3182 	 * Subpage runtime limitation on v1 cache.
3183 	 *
3184 	 * V1 space cache still has some hard codeed PAGE_SIZE usage, while
3185 	 * we're already defaulting to v2 cache, no need to bother v1 as it's
3186 	 * going to be deprecated anyway.
3187 	 */
3188 	if (fs_info->sectorsize < PAGE_SIZE && btrfs_test_opt(fs_info, SPACE_CACHE)) {
3189 		btrfs_warn(fs_info,
3190 	"v1 space cache is not supported for page size %lu with sectorsize %u",
3191 			   PAGE_SIZE, fs_info->sectorsize);
3192 		return -EINVAL;
3193 	}
3194 
3195 	/* This can be called by remount, we need to protect the super block. */
3196 	spin_lock(&fs_info->super_lock);
3197 	btrfs_set_super_incompat_flags(disk_super, incompat);
3198 	spin_unlock(&fs_info->super_lock);
3199 
3200 	return 0;
3201 }
3202 
open_ctree(struct super_block * sb,struct btrfs_fs_devices * fs_devices)3203 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices)
3204 {
3205 	u32 sectorsize;
3206 	u32 nodesize;
3207 	u32 stripesize;
3208 	u64 generation;
3209 	u16 csum_type;
3210 	struct btrfs_super_block *disk_super;
3211 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3212 	struct btrfs_root *tree_root;
3213 	struct btrfs_root *chunk_root;
3214 	int ret;
3215 	int level;
3216 
3217 	ret = init_mount_fs_info(fs_info, sb);
3218 	if (ret)
3219 		goto fail;
3220 
3221 	/* These need to be init'ed before we start creating inodes and such. */
3222 	tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3223 				     GFP_KERNEL);
3224 	fs_info->tree_root = tree_root;
3225 	chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3226 				      GFP_KERNEL);
3227 	fs_info->chunk_root = chunk_root;
3228 	if (!tree_root || !chunk_root) {
3229 		ret = -ENOMEM;
3230 		goto fail;
3231 	}
3232 
3233 	ret = btrfs_init_btree_inode(sb);
3234 	if (ret)
3235 		goto fail;
3236 
3237 	invalidate_bdev(fs_devices->latest_dev->bdev);
3238 
3239 	/*
3240 	 * Read super block and check the signature bytes only
3241 	 */
3242 	disk_super = btrfs_read_dev_super(fs_devices->latest_dev->bdev);
3243 	if (IS_ERR(disk_super)) {
3244 		ret = PTR_ERR(disk_super);
3245 		goto fail_alloc;
3246 	}
3247 
3248 	btrfs_info(fs_info, "first mount of filesystem %pU", disk_super->fsid);
3249 	/*
3250 	 * Verify the type first, if that or the checksum value are
3251 	 * corrupted, we'll find out
3252 	 */
3253 	csum_type = btrfs_super_csum_type(disk_super);
3254 	if (!btrfs_supported_super_csum(csum_type)) {
3255 		btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3256 			  csum_type);
3257 		ret = -EINVAL;
3258 		btrfs_release_disk_super(disk_super);
3259 		goto fail_alloc;
3260 	}
3261 
3262 	fs_info->csum_size = btrfs_super_csum_size(disk_super);
3263 
3264 	ret = btrfs_init_csum_hash(fs_info, csum_type);
3265 	if (ret) {
3266 		btrfs_release_disk_super(disk_super);
3267 		goto fail_alloc;
3268 	}
3269 
3270 	/*
3271 	 * We want to check superblock checksum, the type is stored inside.
3272 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3273 	 */
3274 	if (btrfs_check_super_csum(fs_info, disk_super)) {
3275 		btrfs_err(fs_info, "superblock checksum mismatch");
3276 		ret = -EINVAL;
3277 		btrfs_release_disk_super(disk_super);
3278 		goto fail_alloc;
3279 	}
3280 
3281 	/*
3282 	 * super_copy is zeroed at allocation time and we never touch the
3283 	 * following bytes up to INFO_SIZE, the checksum is calculated from
3284 	 * the whole block of INFO_SIZE
3285 	 */
3286 	memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3287 	btrfs_release_disk_super(disk_super);
3288 
3289 	disk_super = fs_info->super_copy;
3290 
3291 	memcpy(fs_info->super_for_commit, fs_info->super_copy,
3292 	       sizeof(*fs_info->super_for_commit));
3293 
3294 	ret = btrfs_validate_mount_super(fs_info);
3295 	if (ret) {
3296 		btrfs_err(fs_info, "superblock contains fatal errors");
3297 		ret = -EINVAL;
3298 		goto fail_alloc;
3299 	}
3300 
3301 	if (!btrfs_super_root(disk_super)) {
3302 		btrfs_err(fs_info, "invalid superblock tree root bytenr");
3303 		ret = -EINVAL;
3304 		goto fail_alloc;
3305 	}
3306 
3307 	/* check FS state, whether FS is broken. */
3308 	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3309 		WRITE_ONCE(fs_info->fs_error, -EUCLEAN);
3310 
3311 	/* Set up fs_info before parsing mount options */
3312 	nodesize = btrfs_super_nodesize(disk_super);
3313 	sectorsize = btrfs_super_sectorsize(disk_super);
3314 	stripesize = sectorsize;
3315 	fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3316 	fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3317 
3318 	fs_info->nodesize = nodesize;
3319 	fs_info->sectorsize = sectorsize;
3320 	fs_info->sectorsize_bits = ilog2(sectorsize);
3321 	fs_info->sectors_per_page = (PAGE_SIZE >> fs_info->sectorsize_bits);
3322 	fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3323 	fs_info->stripesize = stripesize;
3324 
3325 	/*
3326 	 * Handle the space caching options appropriately now that we have the
3327 	 * super block loaded and validated.
3328 	 */
3329 	btrfs_set_free_space_cache_settings(fs_info);
3330 
3331 	if (!btrfs_check_options(fs_info, &fs_info->mount_opt, sb->s_flags)) {
3332 		ret = -EINVAL;
3333 		goto fail_alloc;
3334 	}
3335 
3336 	ret = btrfs_check_features(fs_info, !sb_rdonly(sb));
3337 	if (ret < 0)
3338 		goto fail_alloc;
3339 
3340 	/*
3341 	 * At this point our mount options are validated, if we set ->max_inline
3342 	 * to something non-standard make sure we truncate it to sectorsize.
3343 	 */
3344 	fs_info->max_inline = min_t(u64, fs_info->max_inline, fs_info->sectorsize);
3345 
3346 	if (sectorsize < PAGE_SIZE)
3347 		btrfs_warn(fs_info,
3348 		"read-write for sector size %u with page size %lu is experimental",
3349 			   sectorsize, PAGE_SIZE);
3350 
3351 	ret = btrfs_init_workqueues(fs_info);
3352 	if (ret)
3353 		goto fail_sb_buffer;
3354 
3355 	sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3356 	sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3357 
3358 	/* Update the values for the current filesystem. */
3359 	sb->s_blocksize = sectorsize;
3360 	sb->s_blocksize_bits = blksize_bits(sectorsize);
3361 	memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3362 
3363 	mutex_lock(&fs_info->chunk_mutex);
3364 	ret = btrfs_read_sys_array(fs_info);
3365 	mutex_unlock(&fs_info->chunk_mutex);
3366 	if (ret) {
3367 		btrfs_err(fs_info, "failed to read the system array: %d", ret);
3368 		goto fail_sb_buffer;
3369 	}
3370 
3371 	generation = btrfs_super_chunk_root_generation(disk_super);
3372 	level = btrfs_super_chunk_root_level(disk_super);
3373 	ret = load_super_root(chunk_root, btrfs_super_chunk_root(disk_super),
3374 			      generation, level);
3375 	if (ret) {
3376 		btrfs_err(fs_info, "failed to read chunk root");
3377 		goto fail_tree_roots;
3378 	}
3379 
3380 	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3381 			   offsetof(struct btrfs_header, chunk_tree_uuid),
3382 			   BTRFS_UUID_SIZE);
3383 
3384 	ret = btrfs_read_chunk_tree(fs_info);
3385 	if (ret) {
3386 		btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3387 		goto fail_tree_roots;
3388 	}
3389 
3390 	/*
3391 	 * At this point we know all the devices that make this filesystem,
3392 	 * including the seed devices but we don't know yet if the replace
3393 	 * target is required. So free devices that are not part of this
3394 	 * filesystem but skip the replace target device which is checked
3395 	 * below in btrfs_init_dev_replace().
3396 	 */
3397 	btrfs_free_extra_devids(fs_devices);
3398 	if (!fs_devices->latest_dev->bdev) {
3399 		btrfs_err(fs_info, "failed to read devices");
3400 		ret = -EIO;
3401 		goto fail_tree_roots;
3402 	}
3403 
3404 	ret = init_tree_roots(fs_info);
3405 	if (ret)
3406 		goto fail_tree_roots;
3407 
3408 	/*
3409 	 * Get zone type information of zoned block devices. This will also
3410 	 * handle emulation of a zoned filesystem if a regular device has the
3411 	 * zoned incompat feature flag set.
3412 	 */
3413 	ret = btrfs_get_dev_zone_info_all_devices(fs_info);
3414 	if (ret) {
3415 		btrfs_err(fs_info,
3416 			  "zoned: failed to read device zone info: %d", ret);
3417 		goto fail_block_groups;
3418 	}
3419 
3420 	/*
3421 	 * If we have a uuid root and we're not being told to rescan we need to
3422 	 * check the generation here so we can set the
3423 	 * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
3424 	 * transaction during a balance or the log replay without updating the
3425 	 * uuid generation, and then if we crash we would rescan the uuid tree,
3426 	 * even though it was perfectly fine.
3427 	 */
3428 	if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3429 	    fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3430 		set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3431 
3432 	ret = btrfs_verify_dev_extents(fs_info);
3433 	if (ret) {
3434 		btrfs_err(fs_info,
3435 			  "failed to verify dev extents against chunks: %d",
3436 			  ret);
3437 		goto fail_block_groups;
3438 	}
3439 	ret = btrfs_recover_balance(fs_info);
3440 	if (ret) {
3441 		btrfs_err(fs_info, "failed to recover balance: %d", ret);
3442 		goto fail_block_groups;
3443 	}
3444 
3445 	ret = btrfs_init_dev_stats(fs_info);
3446 	if (ret) {
3447 		btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3448 		goto fail_block_groups;
3449 	}
3450 
3451 	ret = btrfs_init_dev_replace(fs_info);
3452 	if (ret) {
3453 		btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3454 		goto fail_block_groups;
3455 	}
3456 
3457 	ret = btrfs_check_zoned_mode(fs_info);
3458 	if (ret) {
3459 		btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3460 			  ret);
3461 		goto fail_block_groups;
3462 	}
3463 
3464 	ret = btrfs_sysfs_add_fsid(fs_devices);
3465 	if (ret) {
3466 		btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3467 				ret);
3468 		goto fail_block_groups;
3469 	}
3470 
3471 	ret = btrfs_sysfs_add_mounted(fs_info);
3472 	if (ret) {
3473 		btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3474 		goto fail_fsdev_sysfs;
3475 	}
3476 
3477 	ret = btrfs_init_space_info(fs_info);
3478 	if (ret) {
3479 		btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3480 		goto fail_sysfs;
3481 	}
3482 
3483 	ret = btrfs_read_block_groups(fs_info);
3484 	if (ret) {
3485 		btrfs_err(fs_info, "failed to read block groups: %d", ret);
3486 		goto fail_sysfs;
3487 	}
3488 
3489 	btrfs_free_zone_cache(fs_info);
3490 
3491 	btrfs_check_active_zone_reservation(fs_info);
3492 
3493 	if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices &&
3494 	    !btrfs_check_rw_degradable(fs_info, NULL)) {
3495 		btrfs_warn(fs_info,
3496 		"writable mount is not allowed due to too many missing devices");
3497 		ret = -EINVAL;
3498 		goto fail_sysfs;
3499 	}
3500 
3501 	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, fs_info,
3502 					       "btrfs-cleaner");
3503 	if (IS_ERR(fs_info->cleaner_kthread)) {
3504 		ret = PTR_ERR(fs_info->cleaner_kthread);
3505 		goto fail_sysfs;
3506 	}
3507 
3508 	fs_info->transaction_kthread = kthread_run(transaction_kthread,
3509 						   tree_root,
3510 						   "btrfs-transaction");
3511 	if (IS_ERR(fs_info->transaction_kthread)) {
3512 		ret = PTR_ERR(fs_info->transaction_kthread);
3513 		goto fail_cleaner;
3514 	}
3515 
3516 	ret = btrfs_read_qgroup_config(fs_info);
3517 	if (ret)
3518 		goto fail_trans_kthread;
3519 
3520 	if (btrfs_build_ref_tree(fs_info))
3521 		btrfs_err(fs_info, "couldn't build ref tree");
3522 
3523 	/* do not make disk changes in broken FS or nologreplay is given */
3524 	if (btrfs_super_log_root(disk_super) != 0 &&
3525 	    !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3526 		btrfs_info(fs_info, "start tree-log replay");
3527 		ret = btrfs_replay_log(fs_info, fs_devices);
3528 		if (ret)
3529 			goto fail_qgroup;
3530 	}
3531 
3532 	fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3533 	if (IS_ERR(fs_info->fs_root)) {
3534 		ret = PTR_ERR(fs_info->fs_root);
3535 		btrfs_warn(fs_info, "failed to read fs tree: %d", ret);
3536 		fs_info->fs_root = NULL;
3537 		goto fail_qgroup;
3538 	}
3539 
3540 	if (sb_rdonly(sb))
3541 		return 0;
3542 
3543 	ret = btrfs_start_pre_rw_mount(fs_info);
3544 	if (ret) {
3545 		close_ctree(fs_info);
3546 		return ret;
3547 	}
3548 	btrfs_discard_resume(fs_info);
3549 
3550 	if (fs_info->uuid_root &&
3551 	    (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3552 	     fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3553 		btrfs_info(fs_info, "checking UUID tree");
3554 		ret = btrfs_check_uuid_tree(fs_info);
3555 		if (ret) {
3556 			btrfs_warn(fs_info,
3557 				"failed to check the UUID tree: %d", ret);
3558 			close_ctree(fs_info);
3559 			return ret;
3560 		}
3561 	}
3562 
3563 	set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3564 
3565 	/* Kick the cleaner thread so it'll start deleting snapshots. */
3566 	if (test_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags))
3567 		wake_up_process(fs_info->cleaner_kthread);
3568 
3569 	return 0;
3570 
3571 fail_qgroup:
3572 	btrfs_free_qgroup_config(fs_info);
3573 fail_trans_kthread:
3574 	kthread_stop(fs_info->transaction_kthread);
3575 	btrfs_cleanup_transaction(fs_info);
3576 	btrfs_free_fs_roots(fs_info);
3577 fail_cleaner:
3578 	kthread_stop(fs_info->cleaner_kthread);
3579 
3580 	/*
3581 	 * make sure we're done with the btree inode before we stop our
3582 	 * kthreads
3583 	 */
3584 	filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3585 
3586 fail_sysfs:
3587 	btrfs_sysfs_remove_mounted(fs_info);
3588 
3589 fail_fsdev_sysfs:
3590 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3591 
3592 fail_block_groups:
3593 	btrfs_put_block_group_cache(fs_info);
3594 
3595 fail_tree_roots:
3596 	if (fs_info->data_reloc_root)
3597 		btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3598 	free_root_pointers(fs_info, true);
3599 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3600 
3601 fail_sb_buffer:
3602 	btrfs_stop_all_workers(fs_info);
3603 	btrfs_free_block_groups(fs_info);
3604 fail_alloc:
3605 	btrfs_mapping_tree_free(fs_info);
3606 
3607 	iput(fs_info->btree_inode);
3608 fail:
3609 	btrfs_close_devices(fs_info->fs_devices);
3610 	ASSERT(ret < 0);
3611 	return ret;
3612 }
3613 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3614 
btrfs_end_super_write(struct bio * bio)3615 static void btrfs_end_super_write(struct bio *bio)
3616 {
3617 	struct btrfs_device *device = bio->bi_private;
3618 	struct folio_iter fi;
3619 
3620 	bio_for_each_folio_all(fi, bio) {
3621 		if (bio->bi_status) {
3622 			btrfs_warn_rl_in_rcu(device->fs_info,
3623 				"lost super block write due to IO error on %s (%d)",
3624 				btrfs_dev_name(device),
3625 				blk_status_to_errno(bio->bi_status));
3626 			btrfs_dev_stat_inc_and_print(device,
3627 						     BTRFS_DEV_STAT_WRITE_ERRS);
3628 			/* Ensure failure if the primary sb fails. */
3629 			if (bio->bi_opf & REQ_FUA)
3630 				atomic_add(BTRFS_SUPER_PRIMARY_WRITE_ERROR,
3631 					   &device->sb_write_errors);
3632 			else
3633 				atomic_inc(&device->sb_write_errors);
3634 		}
3635 		folio_unlock(fi.folio);
3636 		folio_put(fi.folio);
3637 	}
3638 
3639 	bio_put(bio);
3640 }
3641 
btrfs_read_dev_one_super(struct block_device * bdev,int copy_num,bool drop_cache)3642 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3643 						   int copy_num, bool drop_cache)
3644 {
3645 	struct btrfs_super_block *super;
3646 	struct page *page;
3647 	u64 bytenr, bytenr_orig;
3648 	struct address_space *mapping = bdev->bd_mapping;
3649 	int ret;
3650 
3651 	bytenr_orig = btrfs_sb_offset(copy_num);
3652 	ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3653 	if (ret == -ENOENT)
3654 		return ERR_PTR(-EINVAL);
3655 	else if (ret)
3656 		return ERR_PTR(ret);
3657 
3658 	if (bytenr + BTRFS_SUPER_INFO_SIZE >= bdev_nr_bytes(bdev))
3659 		return ERR_PTR(-EINVAL);
3660 
3661 	if (drop_cache) {
3662 		/* This should only be called with the primary sb. */
3663 		ASSERT(copy_num == 0);
3664 
3665 		/*
3666 		 * Drop the page of the primary superblock, so later read will
3667 		 * always read from the device.
3668 		 */
3669 		invalidate_inode_pages2_range(mapping,
3670 				bytenr >> PAGE_SHIFT,
3671 				(bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT);
3672 	}
3673 
3674 	page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
3675 	if (IS_ERR(page))
3676 		return ERR_CAST(page);
3677 
3678 	super = page_address(page);
3679 	if (btrfs_super_magic(super) != BTRFS_MAGIC) {
3680 		btrfs_release_disk_super(super);
3681 		return ERR_PTR(-ENODATA);
3682 	}
3683 
3684 	if (btrfs_super_bytenr(super) != bytenr_orig) {
3685 		btrfs_release_disk_super(super);
3686 		return ERR_PTR(-EINVAL);
3687 	}
3688 
3689 	return super;
3690 }
3691 
3692 
btrfs_read_dev_super(struct block_device * bdev)3693 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
3694 {
3695 	struct btrfs_super_block *super, *latest = NULL;
3696 	int i;
3697 	u64 transid = 0;
3698 
3699 	/* we would like to check all the supers, but that would make
3700 	 * a btrfs mount succeed after a mkfs from a different FS.
3701 	 * So, we need to add a special mount option to scan for
3702 	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3703 	 */
3704 	for (i = 0; i < 1; i++) {
3705 		super = btrfs_read_dev_one_super(bdev, i, false);
3706 		if (IS_ERR(super))
3707 			continue;
3708 
3709 		if (!latest || btrfs_super_generation(super) > transid) {
3710 			if (latest)
3711 				btrfs_release_disk_super(super);
3712 
3713 			latest = super;
3714 			transid = btrfs_super_generation(super);
3715 		}
3716 	}
3717 
3718 	return super;
3719 }
3720 
3721 /*
3722  * Write superblock @sb to the @device. Do not wait for completion, all the
3723  * folios we use for writing are locked.
3724  *
3725  * Write @max_mirrors copies of the superblock, where 0 means default that fit
3726  * the expected device size at commit time. Note that max_mirrors must be
3727  * same for write and wait phases.
3728  *
3729  * Return number of errors when folio is not found or submission fails.
3730  */
write_dev_supers(struct btrfs_device * device,struct btrfs_super_block * sb,int max_mirrors)3731 static int write_dev_supers(struct btrfs_device *device,
3732 			    struct btrfs_super_block *sb, int max_mirrors)
3733 {
3734 	struct btrfs_fs_info *fs_info = device->fs_info;
3735 	struct address_space *mapping = device->bdev->bd_mapping;
3736 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
3737 	int i;
3738 	int ret;
3739 	u64 bytenr, bytenr_orig;
3740 
3741 	atomic_set(&device->sb_write_errors, 0);
3742 
3743 	if (max_mirrors == 0)
3744 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3745 
3746 	shash->tfm = fs_info->csum_shash;
3747 
3748 	for (i = 0; i < max_mirrors; i++) {
3749 		struct folio *folio;
3750 		struct bio *bio;
3751 		struct btrfs_super_block *disk_super;
3752 		size_t offset;
3753 
3754 		bytenr_orig = btrfs_sb_offset(i);
3755 		ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
3756 		if (ret == -ENOENT) {
3757 			continue;
3758 		} else if (ret < 0) {
3759 			btrfs_err(device->fs_info,
3760 				"couldn't get super block location for mirror %d",
3761 				i);
3762 			atomic_inc(&device->sb_write_errors);
3763 			continue;
3764 		}
3765 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3766 		    device->commit_total_bytes)
3767 			break;
3768 
3769 		btrfs_set_super_bytenr(sb, bytenr_orig);
3770 
3771 		crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
3772 				    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
3773 				    sb->csum);
3774 
3775 		folio = __filemap_get_folio(mapping, bytenr >> PAGE_SHIFT,
3776 					    FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
3777 					    GFP_NOFS);
3778 		if (IS_ERR(folio)) {
3779 			btrfs_err(device->fs_info,
3780 			    "couldn't get super block page for bytenr %llu",
3781 			    bytenr);
3782 			atomic_inc(&device->sb_write_errors);
3783 			continue;
3784 		}
3785 		ASSERT(folio_order(folio) == 0);
3786 
3787 		offset = offset_in_folio(folio, bytenr);
3788 		disk_super = folio_address(folio) + offset;
3789 		memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
3790 
3791 		/*
3792 		 * Directly use bios here instead of relying on the page cache
3793 		 * to do I/O, so we don't lose the ability to do integrity
3794 		 * checking.
3795 		 */
3796 		bio = bio_alloc(device->bdev, 1,
3797 				REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO,
3798 				GFP_NOFS);
3799 		bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
3800 		bio->bi_private = device;
3801 		bio->bi_end_io = btrfs_end_super_write;
3802 		bio_add_folio_nofail(bio, folio, BTRFS_SUPER_INFO_SIZE, offset);
3803 
3804 		/*
3805 		 * We FUA only the first super block.  The others we allow to
3806 		 * go down lazy and there's a short window where the on-disk
3807 		 * copies might still contain the older version.
3808 		 */
3809 		if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
3810 			bio->bi_opf |= REQ_FUA;
3811 		submit_bio(bio);
3812 
3813 		if (btrfs_advance_sb_log(device, i))
3814 			atomic_inc(&device->sb_write_errors);
3815 	}
3816 	return atomic_read(&device->sb_write_errors) < i ? 0 : -1;
3817 }
3818 
3819 /*
3820  * Wait for write completion of superblocks done by write_dev_supers,
3821  * @max_mirrors same for write and wait phases.
3822  *
3823  * Return -1 if primary super block write failed or when there were no super block
3824  * copies written. Otherwise 0.
3825  */
wait_dev_supers(struct btrfs_device * device,int max_mirrors)3826 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
3827 {
3828 	int i;
3829 	int errors = 0;
3830 	bool primary_failed = false;
3831 	int ret;
3832 	u64 bytenr;
3833 
3834 	if (max_mirrors == 0)
3835 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3836 
3837 	for (i = 0; i < max_mirrors; i++) {
3838 		struct folio *folio;
3839 
3840 		ret = btrfs_sb_log_location(device, i, READ, &bytenr);
3841 		if (ret == -ENOENT) {
3842 			break;
3843 		} else if (ret < 0) {
3844 			errors++;
3845 			if (i == 0)
3846 				primary_failed = true;
3847 			continue;
3848 		}
3849 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3850 		    device->commit_total_bytes)
3851 			break;
3852 
3853 		folio = filemap_get_folio(device->bdev->bd_mapping,
3854 					  bytenr >> PAGE_SHIFT);
3855 		/* If the folio has been removed, then we know it completed. */
3856 		if (IS_ERR(folio))
3857 			continue;
3858 		ASSERT(folio_order(folio) == 0);
3859 
3860 		/* Folio will be unlocked once the write completes. */
3861 		folio_wait_locked(folio);
3862 		folio_put(folio);
3863 	}
3864 
3865 	errors += atomic_read(&device->sb_write_errors);
3866 	if (errors >= BTRFS_SUPER_PRIMARY_WRITE_ERROR)
3867 		primary_failed = true;
3868 	if (primary_failed) {
3869 		btrfs_err(device->fs_info, "error writing primary super block to device %llu",
3870 			  device->devid);
3871 		return -1;
3872 	}
3873 
3874 	return errors < i ? 0 : -1;
3875 }
3876 
3877 /*
3878  * endio for the write_dev_flush, this will wake anyone waiting
3879  * for the barrier when it is done
3880  */
btrfs_end_empty_barrier(struct bio * bio)3881 static void btrfs_end_empty_barrier(struct bio *bio)
3882 {
3883 	bio_uninit(bio);
3884 	complete(bio->bi_private);
3885 }
3886 
3887 /*
3888  * Submit a flush request to the device if it supports it. Error handling is
3889  * done in the waiting counterpart.
3890  */
write_dev_flush(struct btrfs_device * device)3891 static void write_dev_flush(struct btrfs_device *device)
3892 {
3893 	struct bio *bio = &device->flush_bio;
3894 
3895 	device->last_flush_error = BLK_STS_OK;
3896 
3897 	bio_init(bio, device->bdev, NULL, 0,
3898 		 REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH);
3899 	bio->bi_end_io = btrfs_end_empty_barrier;
3900 	init_completion(&device->flush_wait);
3901 	bio->bi_private = &device->flush_wait;
3902 	submit_bio(bio);
3903 	set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3904 }
3905 
3906 /*
3907  * If the flush bio has been submitted by write_dev_flush, wait for it.
3908  * Return true for any error, and false otherwise.
3909  */
wait_dev_flush(struct btrfs_device * device)3910 static bool wait_dev_flush(struct btrfs_device *device)
3911 {
3912 	struct bio *bio = &device->flush_bio;
3913 
3914 	if (!test_and_clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
3915 		return false;
3916 
3917 	wait_for_completion_io(&device->flush_wait);
3918 
3919 	if (bio->bi_status) {
3920 		device->last_flush_error = bio->bi_status;
3921 		btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_FLUSH_ERRS);
3922 		return true;
3923 	}
3924 
3925 	return false;
3926 }
3927 
3928 /*
3929  * send an empty flush down to each device in parallel,
3930  * then wait for them
3931  */
barrier_all_devices(struct btrfs_fs_info * info)3932 static int barrier_all_devices(struct btrfs_fs_info *info)
3933 {
3934 	struct list_head *head;
3935 	struct btrfs_device *dev;
3936 	int errors_wait = 0;
3937 
3938 	lockdep_assert_held(&info->fs_devices->device_list_mutex);
3939 	/* send down all the barriers */
3940 	head = &info->fs_devices->devices;
3941 	list_for_each_entry(dev, head, dev_list) {
3942 		if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3943 			continue;
3944 		if (!dev->bdev)
3945 			continue;
3946 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3947 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3948 			continue;
3949 
3950 		write_dev_flush(dev);
3951 	}
3952 
3953 	/* wait for all the barriers */
3954 	list_for_each_entry(dev, head, dev_list) {
3955 		if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3956 			continue;
3957 		if (!dev->bdev) {
3958 			errors_wait++;
3959 			continue;
3960 		}
3961 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3962 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3963 			continue;
3964 
3965 		if (wait_dev_flush(dev))
3966 			errors_wait++;
3967 	}
3968 
3969 	/*
3970 	 * Checks last_flush_error of disks in order to determine the device
3971 	 * state.
3972 	 */
3973 	if (errors_wait && !btrfs_check_rw_degradable(info, NULL))
3974 		return -EIO;
3975 
3976 	return 0;
3977 }
3978 
btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)3979 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
3980 {
3981 	int raid_type;
3982 	int min_tolerated = INT_MAX;
3983 
3984 	if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
3985 	    (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
3986 		min_tolerated = min_t(int, min_tolerated,
3987 				    btrfs_raid_array[BTRFS_RAID_SINGLE].
3988 				    tolerated_failures);
3989 
3990 	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
3991 		if (raid_type == BTRFS_RAID_SINGLE)
3992 			continue;
3993 		if (!(flags & btrfs_raid_array[raid_type].bg_flag))
3994 			continue;
3995 		min_tolerated = min_t(int, min_tolerated,
3996 				    btrfs_raid_array[raid_type].
3997 				    tolerated_failures);
3998 	}
3999 
4000 	if (min_tolerated == INT_MAX) {
4001 		pr_warn("BTRFS: unknown raid flag: %llu", flags);
4002 		min_tolerated = 0;
4003 	}
4004 
4005 	return min_tolerated;
4006 }
4007 
write_all_supers(struct btrfs_fs_info * fs_info,int max_mirrors)4008 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
4009 {
4010 	struct list_head *head;
4011 	struct btrfs_device *dev;
4012 	struct btrfs_super_block *sb;
4013 	struct btrfs_dev_item *dev_item;
4014 	int ret;
4015 	int do_barriers;
4016 	int max_errors;
4017 	int total_errors = 0;
4018 	u64 flags;
4019 
4020 	do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
4021 
4022 	/*
4023 	 * max_mirrors == 0 indicates we're from commit_transaction,
4024 	 * not from fsync where the tree roots in fs_info have not
4025 	 * been consistent on disk.
4026 	 */
4027 	if (max_mirrors == 0)
4028 		backup_super_roots(fs_info);
4029 
4030 	sb = fs_info->super_for_commit;
4031 	dev_item = &sb->dev_item;
4032 
4033 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
4034 	head = &fs_info->fs_devices->devices;
4035 	max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
4036 
4037 	if (do_barriers) {
4038 		ret = barrier_all_devices(fs_info);
4039 		if (ret) {
4040 			mutex_unlock(
4041 				&fs_info->fs_devices->device_list_mutex);
4042 			btrfs_handle_fs_error(fs_info, ret,
4043 					      "errors while submitting device barriers.");
4044 			return ret;
4045 		}
4046 	}
4047 
4048 	list_for_each_entry(dev, head, dev_list) {
4049 		if (!dev->bdev) {
4050 			total_errors++;
4051 			continue;
4052 		}
4053 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4054 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4055 			continue;
4056 
4057 		btrfs_set_stack_device_generation(dev_item, 0);
4058 		btrfs_set_stack_device_type(dev_item, dev->type);
4059 		btrfs_set_stack_device_id(dev_item, dev->devid);
4060 		btrfs_set_stack_device_total_bytes(dev_item,
4061 						   dev->commit_total_bytes);
4062 		btrfs_set_stack_device_bytes_used(dev_item,
4063 						  dev->commit_bytes_used);
4064 		btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4065 		btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4066 		btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4067 		memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4068 		memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4069 		       BTRFS_FSID_SIZE);
4070 
4071 		flags = btrfs_super_flags(sb);
4072 		btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4073 
4074 		ret = btrfs_validate_write_super(fs_info, sb);
4075 		if (ret < 0) {
4076 			mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4077 			btrfs_handle_fs_error(fs_info, -EUCLEAN,
4078 				"unexpected superblock corruption detected");
4079 			return -EUCLEAN;
4080 		}
4081 
4082 		ret = write_dev_supers(dev, sb, max_mirrors);
4083 		if (ret)
4084 			total_errors++;
4085 	}
4086 	if (total_errors > max_errors) {
4087 		btrfs_err(fs_info, "%d errors while writing supers",
4088 			  total_errors);
4089 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4090 
4091 		/* FUA is masked off if unsupported and can't be the reason */
4092 		btrfs_handle_fs_error(fs_info, -EIO,
4093 				      "%d errors while writing supers",
4094 				      total_errors);
4095 		return -EIO;
4096 	}
4097 
4098 	total_errors = 0;
4099 	list_for_each_entry(dev, head, dev_list) {
4100 		if (!dev->bdev)
4101 			continue;
4102 		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4103 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4104 			continue;
4105 
4106 		ret = wait_dev_supers(dev, max_mirrors);
4107 		if (ret)
4108 			total_errors++;
4109 	}
4110 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4111 	if (total_errors > max_errors) {
4112 		btrfs_handle_fs_error(fs_info, -EIO,
4113 				      "%d errors while writing supers",
4114 				      total_errors);
4115 		return -EIO;
4116 	}
4117 	return 0;
4118 }
4119 
4120 /* Drop a fs root from the radix tree and free it. */
btrfs_drop_and_free_fs_root(struct btrfs_fs_info * fs_info,struct btrfs_root * root)4121 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4122 				  struct btrfs_root *root)
4123 {
4124 	bool drop_ref = false;
4125 
4126 	spin_lock(&fs_info->fs_roots_radix_lock);
4127 	radix_tree_delete(&fs_info->fs_roots_radix,
4128 			  (unsigned long)btrfs_root_id(root));
4129 	if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4130 		drop_ref = true;
4131 	spin_unlock(&fs_info->fs_roots_radix_lock);
4132 
4133 	if (BTRFS_FS_ERROR(fs_info)) {
4134 		ASSERT(root->log_root == NULL);
4135 		if (root->reloc_root) {
4136 			btrfs_put_root(root->reloc_root);
4137 			root->reloc_root = NULL;
4138 		}
4139 	}
4140 
4141 	if (drop_ref)
4142 		btrfs_put_root(root);
4143 }
4144 
btrfs_commit_super(struct btrfs_fs_info * fs_info)4145 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4146 {
4147 	mutex_lock(&fs_info->cleaner_mutex);
4148 	btrfs_run_delayed_iputs(fs_info);
4149 	mutex_unlock(&fs_info->cleaner_mutex);
4150 	wake_up_process(fs_info->cleaner_kthread);
4151 
4152 	/* wait until ongoing cleanup work done */
4153 	down_write(&fs_info->cleanup_work_sem);
4154 	up_write(&fs_info->cleanup_work_sem);
4155 
4156 	return btrfs_commit_current_transaction(fs_info->tree_root);
4157 }
4158 
warn_about_uncommitted_trans(struct btrfs_fs_info * fs_info)4159 static void warn_about_uncommitted_trans(struct btrfs_fs_info *fs_info)
4160 {
4161 	struct btrfs_transaction *trans;
4162 	struct btrfs_transaction *tmp;
4163 	bool found = false;
4164 
4165 	/*
4166 	 * This function is only called at the very end of close_ctree(),
4167 	 * thus no other running transaction, no need to take trans_lock.
4168 	 */
4169 	ASSERT(test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags));
4170 	list_for_each_entry_safe(trans, tmp, &fs_info->trans_list, list) {
4171 		struct extent_state *cached = NULL;
4172 		u64 dirty_bytes = 0;
4173 		u64 cur = 0;
4174 		u64 found_start;
4175 		u64 found_end;
4176 
4177 		found = true;
4178 		while (find_first_extent_bit(&trans->dirty_pages, cur,
4179 			&found_start, &found_end, EXTENT_DIRTY, &cached)) {
4180 			dirty_bytes += found_end + 1 - found_start;
4181 			cur = found_end + 1;
4182 		}
4183 		btrfs_warn(fs_info,
4184 	"transaction %llu (with %llu dirty metadata bytes) is not committed",
4185 			   trans->transid, dirty_bytes);
4186 		btrfs_cleanup_one_transaction(trans);
4187 
4188 		if (trans == fs_info->running_transaction)
4189 			fs_info->running_transaction = NULL;
4190 		list_del_init(&trans->list);
4191 
4192 		btrfs_put_transaction(trans);
4193 		trace_btrfs_transaction_commit(fs_info);
4194 	}
4195 	ASSERT(!found);
4196 }
4197 
close_ctree(struct btrfs_fs_info * fs_info)4198 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4199 {
4200 	int ret;
4201 
4202 	set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4203 
4204 	/*
4205 	 * If we had UNFINISHED_DROPS we could still be processing them, so
4206 	 * clear that bit and wake up relocation so it can stop.
4207 	 * We must do this before stopping the block group reclaim task, because
4208 	 * at btrfs_relocate_block_group() we wait for this bit, and after the
4209 	 * wait we stop with -EINTR if btrfs_fs_closing() returns non-zero - we
4210 	 * have just set BTRFS_FS_CLOSING_START, so btrfs_fs_closing() will
4211 	 * return 1.
4212 	 */
4213 	btrfs_wake_unfinished_drop(fs_info);
4214 
4215 	/*
4216 	 * We may have the reclaim task running and relocating a data block group,
4217 	 * in which case it may create delayed iputs. So stop it before we park
4218 	 * the cleaner kthread otherwise we can get new delayed iputs after
4219 	 * parking the cleaner, and that can make the async reclaim task to hang
4220 	 * if it's waiting for delayed iputs to complete, since the cleaner is
4221 	 * parked and can not run delayed iputs - this will make us hang when
4222 	 * trying to stop the async reclaim task.
4223 	 */
4224 	cancel_work_sync(&fs_info->reclaim_bgs_work);
4225 	/*
4226 	 * We don't want the cleaner to start new transactions, add more delayed
4227 	 * iputs, etc. while we're closing. We can't use kthread_stop() yet
4228 	 * because that frees the task_struct, and the transaction kthread might
4229 	 * still try to wake up the cleaner.
4230 	 */
4231 	kthread_park(fs_info->cleaner_kthread);
4232 
4233 	/* wait for the qgroup rescan worker to stop */
4234 	btrfs_qgroup_wait_for_completion(fs_info, false);
4235 
4236 	/* wait for the uuid_scan task to finish */
4237 	down(&fs_info->uuid_tree_rescan_sem);
4238 	/* avoid complains from lockdep et al., set sem back to initial state */
4239 	up(&fs_info->uuid_tree_rescan_sem);
4240 
4241 	/* pause restriper - we want to resume on mount */
4242 	btrfs_pause_balance(fs_info);
4243 
4244 	btrfs_dev_replace_suspend_for_unmount(fs_info);
4245 
4246 	btrfs_scrub_cancel(fs_info);
4247 
4248 	/* wait for any defraggers to finish */
4249 	wait_event(fs_info->transaction_wait,
4250 		   (atomic_read(&fs_info->defrag_running) == 0));
4251 
4252 	/* clear out the rbtree of defraggable inodes */
4253 	btrfs_cleanup_defrag_inodes(fs_info);
4254 
4255 	/*
4256 	 * Wait for any fixup workers to complete.
4257 	 * If we don't wait for them here and they are still running by the time
4258 	 * we call kthread_stop() against the cleaner kthread further below, we
4259 	 * get an use-after-free on the cleaner because the fixup worker adds an
4260 	 * inode to the list of delayed iputs and then attempts to wakeup the
4261 	 * cleaner kthread, which was already stopped and destroyed. We parked
4262 	 * already the cleaner, but below we run all pending delayed iputs.
4263 	 */
4264 	btrfs_flush_workqueue(fs_info->fixup_workers);
4265 	/*
4266 	 * Similar case here, we have to wait for delalloc workers before we
4267 	 * proceed below and stop the cleaner kthread, otherwise we trigger a
4268 	 * use-after-tree on the cleaner kthread task_struct when a delalloc
4269 	 * worker running submit_compressed_extents() adds a delayed iput, which
4270 	 * does a wake up on the cleaner kthread, which was already freed below
4271 	 * when we call kthread_stop().
4272 	 */
4273 	btrfs_flush_workqueue(fs_info->delalloc_workers);
4274 
4275 	/*
4276 	 * After we parked the cleaner kthread, ordered extents may have
4277 	 * completed and created new delayed iputs. If one of the async reclaim
4278 	 * tasks is running and in the RUN_DELAYED_IPUTS flush state, then we
4279 	 * can hang forever trying to stop it, because if a delayed iput is
4280 	 * added after it ran btrfs_run_delayed_iputs() and before it called
4281 	 * btrfs_wait_on_delayed_iputs(), it will hang forever since there is
4282 	 * no one else to run iputs.
4283 	 *
4284 	 * So wait for all ongoing ordered extents to complete and then run
4285 	 * delayed iputs. This works because once we reach this point no one
4286 	 * can either create new ordered extents nor create delayed iputs
4287 	 * through some other means.
4288 	 *
4289 	 * Also note that btrfs_wait_ordered_roots() is not safe here, because
4290 	 * it waits for BTRFS_ORDERED_COMPLETE to be set on an ordered extent,
4291 	 * but the delayed iput for the respective inode is made only when doing
4292 	 * the final btrfs_put_ordered_extent() (which must happen at
4293 	 * btrfs_finish_ordered_io() when we are unmounting).
4294 	 */
4295 	btrfs_flush_workqueue(fs_info->endio_write_workers);
4296 	/* Ordered extents for free space inodes. */
4297 	btrfs_flush_workqueue(fs_info->endio_freespace_worker);
4298 	btrfs_run_delayed_iputs(fs_info);
4299 
4300 	cancel_work_sync(&fs_info->async_reclaim_work);
4301 	cancel_work_sync(&fs_info->async_data_reclaim_work);
4302 	cancel_work_sync(&fs_info->preempt_reclaim_work);
4303 	cancel_work_sync(&fs_info->em_shrinker_work);
4304 
4305 	/* Cancel or finish ongoing discard work */
4306 	btrfs_discard_cleanup(fs_info);
4307 
4308 	if (!sb_rdonly(fs_info->sb)) {
4309 		/*
4310 		 * The cleaner kthread is stopped, so do one final pass over
4311 		 * unused block groups.
4312 		 */
4313 		btrfs_delete_unused_bgs(fs_info);
4314 
4315 		/*
4316 		 * There might be existing delayed inode workers still running
4317 		 * and holding an empty delayed inode item. We must wait for
4318 		 * them to complete first because they can create a transaction.
4319 		 * This happens when someone calls btrfs_balance_delayed_items()
4320 		 * and then a transaction commit runs the same delayed nodes
4321 		 * before any delayed worker has done something with the nodes.
4322 		 * We must wait for any worker here and not at transaction
4323 		 * commit time since that could cause a deadlock.
4324 		 * This is a very rare case.
4325 		 */
4326 		btrfs_flush_workqueue(fs_info->delayed_workers);
4327 
4328 		ret = btrfs_commit_super(fs_info);
4329 		if (ret)
4330 			btrfs_err(fs_info, "commit super ret %d", ret);
4331 	}
4332 
4333 	if (BTRFS_FS_ERROR(fs_info))
4334 		btrfs_error_commit_super(fs_info);
4335 
4336 	kthread_stop(fs_info->transaction_kthread);
4337 	kthread_stop(fs_info->cleaner_kthread);
4338 
4339 	ASSERT(list_empty(&fs_info->delayed_iputs));
4340 	set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4341 
4342 	if (btrfs_check_quota_leak(fs_info)) {
4343 		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4344 		btrfs_err(fs_info, "qgroup reserved space leaked");
4345 	}
4346 
4347 	btrfs_free_qgroup_config(fs_info);
4348 	ASSERT(list_empty(&fs_info->delalloc_roots));
4349 
4350 	if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4351 		btrfs_info(fs_info, "at unmount delalloc count %lld",
4352 		       percpu_counter_sum(&fs_info->delalloc_bytes));
4353 	}
4354 
4355 	if (percpu_counter_sum(&fs_info->ordered_bytes))
4356 		btrfs_info(fs_info, "at unmount dio bytes count %lld",
4357 			   percpu_counter_sum(&fs_info->ordered_bytes));
4358 
4359 	btrfs_sysfs_remove_mounted(fs_info);
4360 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4361 
4362 	btrfs_put_block_group_cache(fs_info);
4363 
4364 	/*
4365 	 * we must make sure there is not any read request to
4366 	 * submit after we stopping all workers.
4367 	 */
4368 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4369 	btrfs_stop_all_workers(fs_info);
4370 
4371 	/* We shouldn't have any transaction open at this point */
4372 	warn_about_uncommitted_trans(fs_info);
4373 
4374 	clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4375 	free_root_pointers(fs_info, true);
4376 	btrfs_free_fs_roots(fs_info);
4377 
4378 	/*
4379 	 * We must free the block groups after dropping the fs_roots as we could
4380 	 * have had an IO error and have left over tree log blocks that aren't
4381 	 * cleaned up until the fs roots are freed.  This makes the block group
4382 	 * accounting appear to be wrong because there's pending reserved bytes,
4383 	 * so make sure we do the block group cleanup afterwards.
4384 	 */
4385 	btrfs_free_block_groups(fs_info);
4386 
4387 	iput(fs_info->btree_inode);
4388 
4389 	btrfs_mapping_tree_free(fs_info);
4390 	btrfs_close_devices(fs_info->fs_devices);
4391 }
4392 
btrfs_mark_buffer_dirty(struct btrfs_trans_handle * trans,struct extent_buffer * buf)4393 void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
4394 			     struct extent_buffer *buf)
4395 {
4396 	struct btrfs_fs_info *fs_info = buf->fs_info;
4397 	u64 transid = btrfs_header_generation(buf);
4398 
4399 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4400 	/*
4401 	 * This is a fast path so only do this check if we have sanity tests
4402 	 * enabled.  Normal people shouldn't be using unmapped buffers as dirty
4403 	 * outside of the sanity tests.
4404 	 */
4405 	if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4406 		return;
4407 #endif
4408 	/* This is an active transaction (its state < TRANS_STATE_UNBLOCKED). */
4409 	ASSERT(trans->transid == fs_info->generation);
4410 	btrfs_assert_tree_write_locked(buf);
4411 	if (unlikely(transid != fs_info->generation)) {
4412 		btrfs_abort_transaction(trans, -EUCLEAN);
4413 		btrfs_crit(fs_info,
4414 "dirty buffer transid mismatch, logical %llu found transid %llu running transid %llu",
4415 			   buf->start, transid, fs_info->generation);
4416 	}
4417 	set_extent_buffer_dirty(buf);
4418 }
4419 
__btrfs_btree_balance_dirty(struct btrfs_fs_info * fs_info,int flush_delayed)4420 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4421 					int flush_delayed)
4422 {
4423 	/*
4424 	 * looks as though older kernels can get into trouble with
4425 	 * this code, they end up stuck in balance_dirty_pages forever
4426 	 */
4427 	int ret;
4428 
4429 	if (current->flags & PF_MEMALLOC)
4430 		return;
4431 
4432 	if (flush_delayed)
4433 		btrfs_balance_delayed_items(fs_info);
4434 
4435 	ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4436 				     BTRFS_DIRTY_METADATA_THRESH,
4437 				     fs_info->dirty_metadata_batch);
4438 	if (ret > 0) {
4439 		balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4440 	}
4441 }
4442 
btrfs_btree_balance_dirty(struct btrfs_fs_info * fs_info)4443 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4444 {
4445 	__btrfs_btree_balance_dirty(fs_info, 1);
4446 }
4447 
btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info * fs_info)4448 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4449 {
4450 	__btrfs_btree_balance_dirty(fs_info, 0);
4451 }
4452 
btrfs_error_commit_super(struct btrfs_fs_info * fs_info)4453 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4454 {
4455 	/* cleanup FS via transaction */
4456 	btrfs_cleanup_transaction(fs_info);
4457 
4458 	mutex_lock(&fs_info->cleaner_mutex);
4459 	btrfs_run_delayed_iputs(fs_info);
4460 	mutex_unlock(&fs_info->cleaner_mutex);
4461 
4462 	down_write(&fs_info->cleanup_work_sem);
4463 	up_write(&fs_info->cleanup_work_sem);
4464 }
4465 
btrfs_drop_all_logs(struct btrfs_fs_info * fs_info)4466 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4467 {
4468 	struct btrfs_root *gang[8];
4469 	u64 root_objectid = 0;
4470 	int ret;
4471 
4472 	spin_lock(&fs_info->fs_roots_radix_lock);
4473 	while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4474 					     (void **)gang, root_objectid,
4475 					     ARRAY_SIZE(gang))) != 0) {
4476 		int i;
4477 
4478 		for (i = 0; i < ret; i++)
4479 			gang[i] = btrfs_grab_root(gang[i]);
4480 		spin_unlock(&fs_info->fs_roots_radix_lock);
4481 
4482 		for (i = 0; i < ret; i++) {
4483 			if (!gang[i])
4484 				continue;
4485 			root_objectid = btrfs_root_id(gang[i]);
4486 			btrfs_free_log(NULL, gang[i]);
4487 			btrfs_put_root(gang[i]);
4488 		}
4489 		root_objectid++;
4490 		spin_lock(&fs_info->fs_roots_radix_lock);
4491 	}
4492 	spin_unlock(&fs_info->fs_roots_radix_lock);
4493 	btrfs_free_log_root_tree(NULL, fs_info);
4494 }
4495 
btrfs_destroy_ordered_extents(struct btrfs_root * root)4496 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4497 {
4498 	struct btrfs_ordered_extent *ordered;
4499 
4500 	spin_lock(&root->ordered_extent_lock);
4501 	/*
4502 	 * This will just short circuit the ordered completion stuff which will
4503 	 * make sure the ordered extent gets properly cleaned up.
4504 	 */
4505 	list_for_each_entry(ordered, &root->ordered_extents,
4506 			    root_extent_list)
4507 		set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4508 	spin_unlock(&root->ordered_extent_lock);
4509 }
4510 
btrfs_destroy_all_ordered_extents(struct btrfs_fs_info * fs_info)4511 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4512 {
4513 	struct btrfs_root *root;
4514 	LIST_HEAD(splice);
4515 
4516 	spin_lock(&fs_info->ordered_root_lock);
4517 	list_splice_init(&fs_info->ordered_roots, &splice);
4518 	while (!list_empty(&splice)) {
4519 		root = list_first_entry(&splice, struct btrfs_root,
4520 					ordered_root);
4521 		list_move_tail(&root->ordered_root,
4522 			       &fs_info->ordered_roots);
4523 
4524 		spin_unlock(&fs_info->ordered_root_lock);
4525 		btrfs_destroy_ordered_extents(root);
4526 
4527 		cond_resched();
4528 		spin_lock(&fs_info->ordered_root_lock);
4529 	}
4530 	spin_unlock(&fs_info->ordered_root_lock);
4531 
4532 	/*
4533 	 * We need this here because if we've been flipped read-only we won't
4534 	 * get sync() from the umount, so we need to make sure any ordered
4535 	 * extents that haven't had their dirty pages IO start writeout yet
4536 	 * actually get run and error out properly.
4537 	 */
4538 	btrfs_wait_ordered_roots(fs_info, U64_MAX, NULL);
4539 }
4540 
btrfs_destroy_delalloc_inodes(struct btrfs_root * root)4541 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4542 {
4543 	struct btrfs_inode *btrfs_inode;
4544 	LIST_HEAD(splice);
4545 
4546 	spin_lock(&root->delalloc_lock);
4547 	list_splice_init(&root->delalloc_inodes, &splice);
4548 
4549 	while (!list_empty(&splice)) {
4550 		struct inode *inode = NULL;
4551 		btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4552 					       delalloc_inodes);
4553 		btrfs_del_delalloc_inode(btrfs_inode);
4554 		spin_unlock(&root->delalloc_lock);
4555 
4556 		/*
4557 		 * Make sure we get a live inode and that it'll not disappear
4558 		 * meanwhile.
4559 		 */
4560 		inode = igrab(&btrfs_inode->vfs_inode);
4561 		if (inode) {
4562 			unsigned int nofs_flag;
4563 
4564 			nofs_flag = memalloc_nofs_save();
4565 			invalidate_inode_pages2(inode->i_mapping);
4566 			memalloc_nofs_restore(nofs_flag);
4567 			iput(inode);
4568 		}
4569 		spin_lock(&root->delalloc_lock);
4570 	}
4571 	spin_unlock(&root->delalloc_lock);
4572 }
4573 
btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info * fs_info)4574 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4575 {
4576 	struct btrfs_root *root;
4577 	LIST_HEAD(splice);
4578 
4579 	spin_lock(&fs_info->delalloc_root_lock);
4580 	list_splice_init(&fs_info->delalloc_roots, &splice);
4581 	while (!list_empty(&splice)) {
4582 		root = list_first_entry(&splice, struct btrfs_root,
4583 					 delalloc_root);
4584 		root = btrfs_grab_root(root);
4585 		BUG_ON(!root);
4586 		spin_unlock(&fs_info->delalloc_root_lock);
4587 
4588 		btrfs_destroy_delalloc_inodes(root);
4589 		btrfs_put_root(root);
4590 
4591 		spin_lock(&fs_info->delalloc_root_lock);
4592 	}
4593 	spin_unlock(&fs_info->delalloc_root_lock);
4594 }
4595 
btrfs_destroy_marked_extents(struct btrfs_fs_info * fs_info,struct extent_io_tree * dirty_pages,int mark)4596 static void btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
4597 					 struct extent_io_tree *dirty_pages,
4598 					 int mark)
4599 {
4600 	struct extent_buffer *eb;
4601 	u64 start = 0;
4602 	u64 end;
4603 
4604 	while (find_first_extent_bit(dirty_pages, start, &start, &end,
4605 				     mark, NULL)) {
4606 		clear_extent_bits(dirty_pages, start, end, mark);
4607 		while (start <= end) {
4608 			eb = find_extent_buffer(fs_info, start);
4609 			start += fs_info->nodesize;
4610 			if (!eb)
4611 				continue;
4612 
4613 			btrfs_tree_lock(eb);
4614 			wait_on_extent_buffer_writeback(eb);
4615 			btrfs_clear_buffer_dirty(NULL, eb);
4616 			btrfs_tree_unlock(eb);
4617 
4618 			free_extent_buffer_stale(eb);
4619 		}
4620 	}
4621 }
4622 
btrfs_destroy_pinned_extent(struct btrfs_fs_info * fs_info,struct extent_io_tree * unpin)4623 static void btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
4624 					struct extent_io_tree *unpin)
4625 {
4626 	u64 start;
4627 	u64 end;
4628 
4629 	while (1) {
4630 		struct extent_state *cached_state = NULL;
4631 
4632 		/*
4633 		 * The btrfs_finish_extent_commit() may get the same range as
4634 		 * ours between find_first_extent_bit and clear_extent_dirty.
4635 		 * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
4636 		 * the same extent range.
4637 		 */
4638 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
4639 		if (!find_first_extent_bit(unpin, 0, &start, &end,
4640 					   EXTENT_DIRTY, &cached_state)) {
4641 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4642 			break;
4643 		}
4644 
4645 		clear_extent_dirty(unpin, start, end, &cached_state);
4646 		free_extent_state(cached_state);
4647 		btrfs_error_unpin_extent_range(fs_info, start, end);
4648 		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4649 		cond_resched();
4650 	}
4651 }
4652 
btrfs_cleanup_bg_io(struct btrfs_block_group * cache)4653 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
4654 {
4655 	struct inode *inode;
4656 
4657 	inode = cache->io_ctl.inode;
4658 	if (inode) {
4659 		unsigned int nofs_flag;
4660 
4661 		nofs_flag = memalloc_nofs_save();
4662 		invalidate_inode_pages2(inode->i_mapping);
4663 		memalloc_nofs_restore(nofs_flag);
4664 
4665 		BTRFS_I(inode)->generation = 0;
4666 		cache->io_ctl.inode = NULL;
4667 		iput(inode);
4668 	}
4669 	ASSERT(cache->io_ctl.pages == NULL);
4670 	btrfs_put_block_group(cache);
4671 }
4672 
btrfs_cleanup_dirty_bgs(struct btrfs_transaction * cur_trans,struct btrfs_fs_info * fs_info)4673 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
4674 			     struct btrfs_fs_info *fs_info)
4675 {
4676 	struct btrfs_block_group *cache;
4677 
4678 	spin_lock(&cur_trans->dirty_bgs_lock);
4679 	while (!list_empty(&cur_trans->dirty_bgs)) {
4680 		cache = list_first_entry(&cur_trans->dirty_bgs,
4681 					 struct btrfs_block_group,
4682 					 dirty_list);
4683 
4684 		if (!list_empty(&cache->io_list)) {
4685 			spin_unlock(&cur_trans->dirty_bgs_lock);
4686 			list_del_init(&cache->io_list);
4687 			btrfs_cleanup_bg_io(cache);
4688 			spin_lock(&cur_trans->dirty_bgs_lock);
4689 		}
4690 
4691 		list_del_init(&cache->dirty_list);
4692 		spin_lock(&cache->lock);
4693 		cache->disk_cache_state = BTRFS_DC_ERROR;
4694 		spin_unlock(&cache->lock);
4695 
4696 		spin_unlock(&cur_trans->dirty_bgs_lock);
4697 		btrfs_put_block_group(cache);
4698 		btrfs_dec_delayed_refs_rsv_bg_updates(fs_info);
4699 		spin_lock(&cur_trans->dirty_bgs_lock);
4700 	}
4701 	spin_unlock(&cur_trans->dirty_bgs_lock);
4702 
4703 	/*
4704 	 * Refer to the definition of io_bgs member for details why it's safe
4705 	 * to use it without any locking
4706 	 */
4707 	while (!list_empty(&cur_trans->io_bgs)) {
4708 		cache = list_first_entry(&cur_trans->io_bgs,
4709 					 struct btrfs_block_group,
4710 					 io_list);
4711 
4712 		list_del_init(&cache->io_list);
4713 		spin_lock(&cache->lock);
4714 		cache->disk_cache_state = BTRFS_DC_ERROR;
4715 		spin_unlock(&cache->lock);
4716 		btrfs_cleanup_bg_io(cache);
4717 	}
4718 }
4719 
btrfs_free_all_qgroup_pertrans(struct btrfs_fs_info * fs_info)4720 static void btrfs_free_all_qgroup_pertrans(struct btrfs_fs_info *fs_info)
4721 {
4722 	struct btrfs_root *gang[8];
4723 	int i;
4724 	int ret;
4725 
4726 	spin_lock(&fs_info->fs_roots_radix_lock);
4727 	while (1) {
4728 		ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
4729 						 (void **)gang, 0,
4730 						 ARRAY_SIZE(gang),
4731 						 BTRFS_ROOT_TRANS_TAG);
4732 		if (ret == 0)
4733 			break;
4734 		for (i = 0; i < ret; i++) {
4735 			struct btrfs_root *root = gang[i];
4736 
4737 			btrfs_qgroup_free_meta_all_pertrans(root);
4738 			radix_tree_tag_clear(&fs_info->fs_roots_radix,
4739 					(unsigned long)btrfs_root_id(root),
4740 					BTRFS_ROOT_TRANS_TAG);
4741 		}
4742 	}
4743 	spin_unlock(&fs_info->fs_roots_radix_lock);
4744 }
4745 
btrfs_cleanup_one_transaction(struct btrfs_transaction * cur_trans)4746 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans)
4747 {
4748 	struct btrfs_fs_info *fs_info = cur_trans->fs_info;
4749 	struct btrfs_device *dev, *tmp;
4750 
4751 	btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
4752 	ASSERT(list_empty(&cur_trans->dirty_bgs));
4753 	ASSERT(list_empty(&cur_trans->io_bgs));
4754 
4755 	list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
4756 				 post_commit_list) {
4757 		list_del_init(&dev->post_commit_list);
4758 	}
4759 
4760 	btrfs_destroy_delayed_refs(cur_trans);
4761 
4762 	cur_trans->state = TRANS_STATE_COMMIT_START;
4763 	wake_up(&fs_info->transaction_blocked_wait);
4764 
4765 	cur_trans->state = TRANS_STATE_UNBLOCKED;
4766 	wake_up(&fs_info->transaction_wait);
4767 
4768 	btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
4769 				     EXTENT_DIRTY);
4770 	btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
4771 
4772 	cur_trans->state =TRANS_STATE_COMPLETED;
4773 	wake_up(&cur_trans->commit_wait);
4774 }
4775 
btrfs_cleanup_transaction(struct btrfs_fs_info * fs_info)4776 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
4777 {
4778 	struct btrfs_transaction *t;
4779 
4780 	mutex_lock(&fs_info->transaction_kthread_mutex);
4781 
4782 	spin_lock(&fs_info->trans_lock);
4783 	while (!list_empty(&fs_info->trans_list)) {
4784 		t = list_first_entry(&fs_info->trans_list,
4785 				     struct btrfs_transaction, list);
4786 		if (t->state >= TRANS_STATE_COMMIT_PREP) {
4787 			refcount_inc(&t->use_count);
4788 			spin_unlock(&fs_info->trans_lock);
4789 			btrfs_wait_for_commit(fs_info, t->transid);
4790 			btrfs_put_transaction(t);
4791 			spin_lock(&fs_info->trans_lock);
4792 			continue;
4793 		}
4794 		if (t == fs_info->running_transaction) {
4795 			t->state = TRANS_STATE_COMMIT_DOING;
4796 			spin_unlock(&fs_info->trans_lock);
4797 			/*
4798 			 * We wait for 0 num_writers since we don't hold a trans
4799 			 * handle open currently for this transaction.
4800 			 */
4801 			wait_event(t->writer_wait,
4802 				   atomic_read(&t->num_writers) == 0);
4803 		} else {
4804 			spin_unlock(&fs_info->trans_lock);
4805 		}
4806 		btrfs_cleanup_one_transaction(t);
4807 
4808 		spin_lock(&fs_info->trans_lock);
4809 		if (t == fs_info->running_transaction)
4810 			fs_info->running_transaction = NULL;
4811 		list_del_init(&t->list);
4812 		spin_unlock(&fs_info->trans_lock);
4813 
4814 		btrfs_put_transaction(t);
4815 		trace_btrfs_transaction_commit(fs_info);
4816 		spin_lock(&fs_info->trans_lock);
4817 	}
4818 	spin_unlock(&fs_info->trans_lock);
4819 	btrfs_destroy_all_ordered_extents(fs_info);
4820 	btrfs_destroy_delayed_inodes(fs_info);
4821 	btrfs_assert_delayed_root_empty(fs_info);
4822 	btrfs_destroy_all_delalloc_inodes(fs_info);
4823 	btrfs_drop_all_logs(fs_info);
4824 	btrfs_free_all_qgroup_pertrans(fs_info);
4825 	mutex_unlock(&fs_info->transaction_kthread_mutex);
4826 
4827 	return 0;
4828 }
4829 
btrfs_init_root_free_objectid(struct btrfs_root * root)4830 int btrfs_init_root_free_objectid(struct btrfs_root *root)
4831 {
4832 	struct btrfs_path *path;
4833 	int ret;
4834 	struct extent_buffer *l;
4835 	struct btrfs_key search_key;
4836 	struct btrfs_key found_key;
4837 	int slot;
4838 
4839 	path = btrfs_alloc_path();
4840 	if (!path)
4841 		return -ENOMEM;
4842 
4843 	search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
4844 	search_key.type = -1;
4845 	search_key.offset = (u64)-1;
4846 	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
4847 	if (ret < 0)
4848 		goto error;
4849 	if (ret == 0) {
4850 		/*
4851 		 * Key with offset -1 found, there would have to exist a root
4852 		 * with such id, but this is out of valid range.
4853 		 */
4854 		ret = -EUCLEAN;
4855 		goto error;
4856 	}
4857 	if (path->slots[0] > 0) {
4858 		slot = path->slots[0] - 1;
4859 		l = path->nodes[0];
4860 		btrfs_item_key_to_cpu(l, &found_key, slot);
4861 		root->free_objectid = max_t(u64, found_key.objectid + 1,
4862 					    BTRFS_FIRST_FREE_OBJECTID);
4863 	} else {
4864 		root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
4865 	}
4866 	ret = 0;
4867 error:
4868 	btrfs_free_path(path);
4869 	return ret;
4870 }
4871 
btrfs_get_free_objectid(struct btrfs_root * root,u64 * objectid)4872 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
4873 {
4874 	int ret;
4875 	mutex_lock(&root->objectid_mutex);
4876 
4877 	if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
4878 		btrfs_warn(root->fs_info,
4879 			   "the objectid of root %llu reaches its highest value",
4880 			   btrfs_root_id(root));
4881 		ret = -ENOSPC;
4882 		goto out;
4883 	}
4884 
4885 	*objectid = root->free_objectid++;
4886 	ret = 0;
4887 out:
4888 	mutex_unlock(&root->objectid_mutex);
4889 	return ret;
4890 }
4891