xref: /linux/fs/btrfs/tree-checker.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) Qu Wenruo 2017.  All rights reserved.
4  */
5 
6 /*
7  * The module is used to catch unexpected/corrupted tree block data.
8  * Such behavior can be caused either by a fuzzed image or bugs.
9  *
10  * The objective is to do leaf/node validation checks when tree block is read
11  * from disk, and check *every* possible member, so other code won't
12  * need to checking them again.
13  *
14  * Due to the potential and unwanted damage, every checker needs to be
15  * carefully reviewed otherwise so it does not prevent mount of valid images.
16  */
17 
18 #include <linux/types.h>
19 #include <linux/stddef.h>
20 #include <linux/error-injection.h>
21 #include "messages.h"
22 #include "ctree.h"
23 #include "tree-checker.h"
24 #include "compression.h"
25 #include "volumes.h"
26 #include "misc.h"
27 #include "fs.h"
28 #include "accessors.h"
29 #include "file-item.h"
30 #include "inode-item.h"
31 #include "dir-item.h"
32 #include "extent-tree.h"
33 
34 /*
35  * Error message should follow the following format:
36  * corrupt <type>: <identifier>, <reason>[, <bad_value>]
37  *
38  * @type:	leaf or node
39  * @identifier:	the necessary info to locate the leaf/node.
40  * 		It's recommended to decode key.objecitd/offset if it's
41  * 		meaningful.
42  * @reason:	describe the error
43  * @bad_value:	optional, it's recommended to output bad value and its
44  *		expected value (range).
45  *
46  * Since comma is used to separate the components, only space is allowed
47  * inside each component.
48  */
49 
50 /*
51  * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
52  * Allows callers to customize the output.
53  */
54 __printf(3, 4)
55 __cold
56 static void generic_err(const struct extent_buffer *eb, int slot,
57 			const char *fmt, ...)
58 {
59 	const struct btrfs_fs_info *fs_info = eb->fs_info;
60 	struct va_format vaf;
61 	va_list args;
62 
63 	va_start(args, fmt);
64 
65 	vaf.fmt = fmt;
66 	vaf.va = &args;
67 
68 	dump_page(folio_page(eb->folios[0], 0), "eb page dump");
69 	btrfs_crit(fs_info,
70 		"corrupt %s: root=%llu block=%llu slot=%d, %pV",
71 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
72 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, &vaf);
73 	va_end(args);
74 }
75 
76 /*
77  * Customized reporter for extent data item, since its key objectid and
78  * offset has its own meaning.
79  */
80 __printf(3, 4)
81 __cold
82 static void file_extent_err(const struct extent_buffer *eb, int slot,
83 			    const char *fmt, ...)
84 {
85 	const struct btrfs_fs_info *fs_info = eb->fs_info;
86 	struct btrfs_key key;
87 	struct va_format vaf;
88 	va_list args;
89 
90 	btrfs_item_key_to_cpu(eb, &key, slot);
91 	va_start(args, fmt);
92 
93 	vaf.fmt = fmt;
94 	vaf.va = &args;
95 
96 	dump_page(folio_page(eb->folios[0], 0), "eb page dump");
97 	btrfs_crit(fs_info,
98 	"corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
99 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
100 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
101 		key.objectid, key.offset, &vaf);
102 	va_end(args);
103 }
104 
105 /*
106  * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
107  * Else return 1
108  */
109 #define CHECK_FE_ALIGNED(leaf, slot, fi, name, alignment)		      \
110 ({									      \
111 	if (unlikely(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)),      \
112 				 (alignment))))				      \
113 		file_extent_err((leaf), (slot),				      \
114 	"invalid %s for file extent, have %llu, should be aligned to %u",     \
115 			(#name), btrfs_file_extent_##name((leaf), (fi)),      \
116 			(alignment));					      \
117 	(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment)));   \
118 })
119 
120 static u64 file_extent_end(struct extent_buffer *leaf,
121 			   struct btrfs_key *key,
122 			   struct btrfs_file_extent_item *extent)
123 {
124 	u64 end;
125 	u64 len;
126 
127 	if (btrfs_file_extent_type(leaf, extent) == BTRFS_FILE_EXTENT_INLINE) {
128 		len = btrfs_file_extent_ram_bytes(leaf, extent);
129 		end = ALIGN(key->offset + len, leaf->fs_info->sectorsize);
130 	} else {
131 		len = btrfs_file_extent_num_bytes(leaf, extent);
132 		end = key->offset + len;
133 	}
134 	return end;
135 }
136 
137 /*
138  * Customized report for dir_item, the only new important information is
139  * key->objectid, which represents inode number
140  */
141 __printf(3, 4)
142 __cold
143 static void dir_item_err(const struct extent_buffer *eb, int slot,
144 			 const char *fmt, ...)
145 {
146 	const struct btrfs_fs_info *fs_info = eb->fs_info;
147 	struct btrfs_key key;
148 	struct va_format vaf;
149 	va_list args;
150 
151 	btrfs_item_key_to_cpu(eb, &key, slot);
152 	va_start(args, fmt);
153 
154 	vaf.fmt = fmt;
155 	vaf.va = &args;
156 
157 	dump_page(folio_page(eb->folios[0], 0), "eb page dump");
158 	btrfs_crit(fs_info,
159 		"corrupt %s: root=%llu block=%llu slot=%d ino=%llu, %pV",
160 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
161 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
162 		key.objectid, &vaf);
163 	va_end(args);
164 }
165 
166 /*
167  * This functions checks prev_key->objectid, to ensure current key and prev_key
168  * share the same objectid as inode number.
169  *
170  * This is to detect missing INODE_ITEM in subvolume trees.
171  *
172  * Return true if everything is OK or we don't need to check.
173  * Return false if anything is wrong.
174  */
175 static bool check_prev_ino(struct extent_buffer *leaf,
176 			   struct btrfs_key *key, int slot,
177 			   struct btrfs_key *prev_key)
178 {
179 	/* No prev key, skip check */
180 	if (slot == 0)
181 		return true;
182 
183 	/* Only these key->types needs to be checked */
184 	ASSERT(key->type == BTRFS_XATTR_ITEM_KEY ||
185 	       key->type == BTRFS_INODE_REF_KEY ||
186 	       key->type == BTRFS_DIR_INDEX_KEY ||
187 	       key->type == BTRFS_DIR_ITEM_KEY ||
188 	       key->type == BTRFS_EXTENT_DATA_KEY);
189 
190 	/*
191 	 * Only subvolume trees along with their reloc trees need this check.
192 	 * Things like log tree doesn't follow this ino requirement.
193 	 */
194 	if (!is_fstree(btrfs_header_owner(leaf)))
195 		return true;
196 
197 	if (key->objectid == prev_key->objectid)
198 		return true;
199 
200 	/* Error found */
201 	dir_item_err(leaf, slot,
202 		"invalid previous key objectid, have %llu expect %llu",
203 		prev_key->objectid, key->objectid);
204 	return false;
205 }
206 static int check_extent_data_item(struct extent_buffer *leaf,
207 				  struct btrfs_key *key, int slot,
208 				  struct btrfs_key *prev_key)
209 {
210 	struct btrfs_fs_info *fs_info = leaf->fs_info;
211 	struct btrfs_file_extent_item *fi;
212 	u32 sectorsize = fs_info->sectorsize;
213 	u32 item_size = btrfs_item_size(leaf, slot);
214 	u64 extent_end;
215 
216 	if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
217 		file_extent_err(leaf, slot,
218 "unaligned file_offset for file extent, have %llu should be aligned to %u",
219 			key->offset, sectorsize);
220 		return -EUCLEAN;
221 	}
222 
223 	/*
224 	 * Previous key must have the same key->objectid (ino).
225 	 * It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
226 	 * But if objectids mismatch, it means we have a missing
227 	 * INODE_ITEM.
228 	 */
229 	if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
230 		return -EUCLEAN;
231 
232 	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
233 
234 	/*
235 	 * Make sure the item contains at least inline header, so the file
236 	 * extent type is not some garbage.
237 	 */
238 	if (unlikely(item_size < BTRFS_FILE_EXTENT_INLINE_DATA_START)) {
239 		file_extent_err(leaf, slot,
240 				"invalid item size, have %u expect [%zu, %u)",
241 				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START,
242 				SZ_4K);
243 		return -EUCLEAN;
244 	}
245 	if (unlikely(btrfs_file_extent_type(leaf, fi) >=
246 		     BTRFS_NR_FILE_EXTENT_TYPES)) {
247 		file_extent_err(leaf, slot,
248 		"invalid type for file extent, have %u expect range [0, %u]",
249 			btrfs_file_extent_type(leaf, fi),
250 			BTRFS_NR_FILE_EXTENT_TYPES - 1);
251 		return -EUCLEAN;
252 	}
253 
254 	/*
255 	 * Support for new compression/encryption must introduce incompat flag,
256 	 * and must be caught in open_ctree().
257 	 */
258 	if (unlikely(btrfs_file_extent_compression(leaf, fi) >=
259 		     BTRFS_NR_COMPRESS_TYPES)) {
260 		file_extent_err(leaf, slot,
261 	"invalid compression for file extent, have %u expect range [0, %u]",
262 			btrfs_file_extent_compression(leaf, fi),
263 			BTRFS_NR_COMPRESS_TYPES - 1);
264 		return -EUCLEAN;
265 	}
266 	if (unlikely(btrfs_file_extent_encryption(leaf, fi))) {
267 		file_extent_err(leaf, slot,
268 			"invalid encryption for file extent, have %u expect 0",
269 			btrfs_file_extent_encryption(leaf, fi));
270 		return -EUCLEAN;
271 	}
272 	if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
273 		/* Inline extent must have 0 as key offset */
274 		if (unlikely(key->offset)) {
275 			file_extent_err(leaf, slot,
276 		"invalid file_offset for inline file extent, have %llu expect 0",
277 				key->offset);
278 			return -EUCLEAN;
279 		}
280 
281 		/* Compressed inline extent has no on-disk size, skip it */
282 		if (btrfs_file_extent_compression(leaf, fi) !=
283 		    BTRFS_COMPRESS_NONE)
284 			return 0;
285 
286 		/* Uncompressed inline extent size must match item size */
287 		if (unlikely(item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
288 					  btrfs_file_extent_ram_bytes(leaf, fi))) {
289 			file_extent_err(leaf, slot,
290 	"invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
291 				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
292 				btrfs_file_extent_ram_bytes(leaf, fi));
293 			return -EUCLEAN;
294 		}
295 		return 0;
296 	}
297 
298 	/* Regular or preallocated extent has fixed item size */
299 	if (unlikely(item_size != sizeof(*fi))) {
300 		file_extent_err(leaf, slot,
301 	"invalid item size for reg/prealloc file extent, have %u expect %zu",
302 			item_size, sizeof(*fi));
303 		return -EUCLEAN;
304 	}
305 	if (unlikely(CHECK_FE_ALIGNED(leaf, slot, fi, ram_bytes, sectorsize) ||
306 		     CHECK_FE_ALIGNED(leaf, slot, fi, disk_bytenr, sectorsize) ||
307 		     CHECK_FE_ALIGNED(leaf, slot, fi, disk_num_bytes, sectorsize) ||
308 		     CHECK_FE_ALIGNED(leaf, slot, fi, offset, sectorsize) ||
309 		     CHECK_FE_ALIGNED(leaf, slot, fi, num_bytes, sectorsize)))
310 		return -EUCLEAN;
311 
312 	/* Catch extent end overflow */
313 	if (unlikely(check_add_overflow(btrfs_file_extent_num_bytes(leaf, fi),
314 					key->offset, &extent_end))) {
315 		file_extent_err(leaf, slot,
316 	"extent end overflow, have file offset %llu extent num bytes %llu",
317 				key->offset,
318 				btrfs_file_extent_num_bytes(leaf, fi));
319 		return -EUCLEAN;
320 	}
321 
322 	/*
323 	 * Check that no two consecutive file extent items, in the same leaf,
324 	 * present ranges that overlap each other.
325 	 */
326 	if (slot > 0 &&
327 	    prev_key->objectid == key->objectid &&
328 	    prev_key->type == BTRFS_EXTENT_DATA_KEY) {
329 		struct btrfs_file_extent_item *prev_fi;
330 		u64 prev_end;
331 
332 		prev_fi = btrfs_item_ptr(leaf, slot - 1,
333 					 struct btrfs_file_extent_item);
334 		prev_end = file_extent_end(leaf, prev_key, prev_fi);
335 		if (unlikely(prev_end > key->offset)) {
336 			file_extent_err(leaf, slot - 1,
337 "file extent end range (%llu) goes beyond start offset (%llu) of the next file extent",
338 					prev_end, key->offset);
339 			return -EUCLEAN;
340 		}
341 	}
342 
343 	return 0;
344 }
345 
346 static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
347 			   int slot, struct btrfs_key *prev_key)
348 {
349 	struct btrfs_fs_info *fs_info = leaf->fs_info;
350 	u32 sectorsize = fs_info->sectorsize;
351 	const u32 csumsize = fs_info->csum_size;
352 
353 	if (unlikely(key->objectid != BTRFS_EXTENT_CSUM_OBJECTID)) {
354 		generic_err(leaf, slot,
355 		"invalid key objectid for csum item, have %llu expect %llu",
356 			key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
357 		return -EUCLEAN;
358 	}
359 	if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
360 		generic_err(leaf, slot,
361 	"unaligned key offset for csum item, have %llu should be aligned to %u",
362 			key->offset, sectorsize);
363 		return -EUCLEAN;
364 	}
365 	if (unlikely(!IS_ALIGNED(btrfs_item_size(leaf, slot), csumsize))) {
366 		generic_err(leaf, slot,
367 	"unaligned item size for csum item, have %u should be aligned to %u",
368 			btrfs_item_size(leaf, slot), csumsize);
369 		return -EUCLEAN;
370 	}
371 	if (slot > 0 && prev_key->type == BTRFS_EXTENT_CSUM_KEY) {
372 		u64 prev_csum_end;
373 		u32 prev_item_size;
374 
375 		prev_item_size = btrfs_item_size(leaf, slot - 1);
376 		prev_csum_end = (prev_item_size / csumsize) * sectorsize;
377 		prev_csum_end += prev_key->offset;
378 		if (unlikely(prev_csum_end > key->offset)) {
379 			generic_err(leaf, slot - 1,
380 "csum end range (%llu) goes beyond the start range (%llu) of the next csum item",
381 				    prev_csum_end, key->offset);
382 			return -EUCLEAN;
383 		}
384 	}
385 	return 0;
386 }
387 
388 /* Inode item error output has the same format as dir_item_err() */
389 #define inode_item_err(eb, slot, fmt, ...)			\
390 	dir_item_err(eb, slot, fmt, __VA_ARGS__)
391 
392 static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key,
393 			   int slot)
394 {
395 	struct btrfs_key item_key;
396 	bool is_inode_item;
397 
398 	btrfs_item_key_to_cpu(leaf, &item_key, slot);
399 	is_inode_item = (item_key.type == BTRFS_INODE_ITEM_KEY);
400 
401 	/* For XATTR_ITEM, location key should be all 0 */
402 	if (item_key.type == BTRFS_XATTR_ITEM_KEY) {
403 		if (unlikely(key->objectid != 0 || key->type != 0 ||
404 			     key->offset != 0))
405 			return -EUCLEAN;
406 		return 0;
407 	}
408 
409 	if (unlikely((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
410 		      key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
411 		     key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
412 		     key->objectid != BTRFS_FREE_INO_OBJECTID)) {
413 		if (is_inode_item) {
414 			generic_err(leaf, slot,
415 	"invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
416 				key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
417 				BTRFS_FIRST_FREE_OBJECTID,
418 				BTRFS_LAST_FREE_OBJECTID,
419 				BTRFS_FREE_INO_OBJECTID);
420 		} else {
421 			dir_item_err(leaf, slot,
422 "invalid location key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
423 				key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
424 				BTRFS_FIRST_FREE_OBJECTID,
425 				BTRFS_LAST_FREE_OBJECTID,
426 				BTRFS_FREE_INO_OBJECTID);
427 		}
428 		return -EUCLEAN;
429 	}
430 	if (unlikely(key->offset != 0)) {
431 		if (is_inode_item)
432 			inode_item_err(leaf, slot,
433 				       "invalid key offset: has %llu expect 0",
434 				       key->offset);
435 		else
436 			dir_item_err(leaf, slot,
437 				"invalid location key offset:has %llu expect 0",
438 				key->offset);
439 		return -EUCLEAN;
440 	}
441 	return 0;
442 }
443 
444 static int check_root_key(struct extent_buffer *leaf, struct btrfs_key *key,
445 			  int slot)
446 {
447 	struct btrfs_key item_key;
448 	bool is_root_item;
449 
450 	btrfs_item_key_to_cpu(leaf, &item_key, slot);
451 	is_root_item = (item_key.type == BTRFS_ROOT_ITEM_KEY);
452 
453 	/*
454 	 * Bad rootid for reloc trees.
455 	 *
456 	 * Reloc trees are only for subvolume trees, other trees only need
457 	 * to be COWed to be relocated.
458 	 */
459 	if (unlikely(is_root_item && key->objectid == BTRFS_TREE_RELOC_OBJECTID &&
460 		     !is_fstree(key->offset))) {
461 		generic_err(leaf, slot,
462 		"invalid reloc tree for root %lld, root id is not a subvolume tree",
463 			    key->offset);
464 		return -EUCLEAN;
465 	}
466 
467 	/* No such tree id */
468 	if (unlikely(key->objectid == 0)) {
469 		if (is_root_item)
470 			generic_err(leaf, slot, "invalid root id 0");
471 		else
472 			dir_item_err(leaf, slot,
473 				     "invalid location key root id 0");
474 		return -EUCLEAN;
475 	}
476 
477 	/* DIR_ITEM/INDEX/INODE_REF is not allowed to point to non-fs trees */
478 	if (unlikely(!is_fstree(key->objectid) && !is_root_item)) {
479 		dir_item_err(leaf, slot,
480 		"invalid location key objectid, have %llu expect [%llu, %llu]",
481 				key->objectid, BTRFS_FIRST_FREE_OBJECTID,
482 				BTRFS_LAST_FREE_OBJECTID);
483 		return -EUCLEAN;
484 	}
485 
486 	/*
487 	 * ROOT_ITEM with non-zero offset means this is a snapshot, created at
488 	 * @offset transid.
489 	 * Furthermore, for location key in DIR_ITEM, its offset is always -1.
490 	 *
491 	 * So here we only check offset for reloc tree whose key->offset must
492 	 * be a valid tree.
493 	 */
494 	if (unlikely(key->objectid == BTRFS_TREE_RELOC_OBJECTID &&
495 		     key->offset == 0)) {
496 		generic_err(leaf, slot, "invalid root id 0 for reloc tree");
497 		return -EUCLEAN;
498 	}
499 	return 0;
500 }
501 
502 static int check_dir_item(struct extent_buffer *leaf,
503 			  struct btrfs_key *key, struct btrfs_key *prev_key,
504 			  int slot)
505 {
506 	struct btrfs_fs_info *fs_info = leaf->fs_info;
507 	struct btrfs_dir_item *di;
508 	u32 item_size = btrfs_item_size(leaf, slot);
509 	u32 cur = 0;
510 
511 	if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
512 		return -EUCLEAN;
513 
514 	di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
515 	while (cur < item_size) {
516 		struct btrfs_key location_key;
517 		u32 name_len;
518 		u32 data_len;
519 		u32 max_name_len;
520 		u32 total_size;
521 		u32 name_hash;
522 		u8 dir_type;
523 		int ret;
524 
525 		/* header itself should not cross item boundary */
526 		if (unlikely(cur + sizeof(*di) > item_size)) {
527 			dir_item_err(leaf, slot,
528 		"dir item header crosses item boundary, have %zu boundary %u",
529 				cur + sizeof(*di), item_size);
530 			return -EUCLEAN;
531 		}
532 
533 		/* Location key check */
534 		btrfs_dir_item_key_to_cpu(leaf, di, &location_key);
535 		if (location_key.type == BTRFS_ROOT_ITEM_KEY) {
536 			ret = check_root_key(leaf, &location_key, slot);
537 			if (unlikely(ret < 0))
538 				return ret;
539 		} else if (location_key.type == BTRFS_INODE_ITEM_KEY ||
540 			   location_key.type == 0) {
541 			ret = check_inode_key(leaf, &location_key, slot);
542 			if (unlikely(ret < 0))
543 				return ret;
544 		} else {
545 			dir_item_err(leaf, slot,
546 			"invalid location key type, have %u, expect %u or %u",
547 				     location_key.type, BTRFS_ROOT_ITEM_KEY,
548 				     BTRFS_INODE_ITEM_KEY);
549 			return -EUCLEAN;
550 		}
551 
552 		/* dir type check */
553 		dir_type = btrfs_dir_ftype(leaf, di);
554 		if (unlikely(dir_type >= BTRFS_FT_MAX)) {
555 			dir_item_err(leaf, slot,
556 			"invalid dir item type, have %u expect [0, %u)",
557 				dir_type, BTRFS_FT_MAX);
558 			return -EUCLEAN;
559 		}
560 
561 		if (unlikely(key->type == BTRFS_XATTR_ITEM_KEY &&
562 			     dir_type != BTRFS_FT_XATTR)) {
563 			dir_item_err(leaf, slot,
564 		"invalid dir item type for XATTR key, have %u expect %u",
565 				dir_type, BTRFS_FT_XATTR);
566 			return -EUCLEAN;
567 		}
568 		if (unlikely(dir_type == BTRFS_FT_XATTR &&
569 			     key->type != BTRFS_XATTR_ITEM_KEY)) {
570 			dir_item_err(leaf, slot,
571 			"xattr dir type found for non-XATTR key");
572 			return -EUCLEAN;
573 		}
574 		if (dir_type == BTRFS_FT_XATTR)
575 			max_name_len = XATTR_NAME_MAX;
576 		else
577 			max_name_len = BTRFS_NAME_LEN;
578 
579 		/* Name/data length check */
580 		name_len = btrfs_dir_name_len(leaf, di);
581 		data_len = btrfs_dir_data_len(leaf, di);
582 		if (unlikely(name_len > max_name_len)) {
583 			dir_item_err(leaf, slot,
584 			"dir item name len too long, have %u max %u",
585 				name_len, max_name_len);
586 			return -EUCLEAN;
587 		}
588 		if (unlikely(name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info))) {
589 			dir_item_err(leaf, slot,
590 			"dir item name and data len too long, have %u max %u",
591 				name_len + data_len,
592 				BTRFS_MAX_XATTR_SIZE(fs_info));
593 			return -EUCLEAN;
594 		}
595 
596 		if (unlikely(data_len && dir_type != BTRFS_FT_XATTR)) {
597 			dir_item_err(leaf, slot,
598 			"dir item with invalid data len, have %u expect 0",
599 				data_len);
600 			return -EUCLEAN;
601 		}
602 
603 		total_size = sizeof(*di) + name_len + data_len;
604 
605 		/* header and name/data should not cross item boundary */
606 		if (unlikely(cur + total_size > item_size)) {
607 			dir_item_err(leaf, slot,
608 		"dir item data crosses item boundary, have %u boundary %u",
609 				cur + total_size, item_size);
610 			return -EUCLEAN;
611 		}
612 
613 		/*
614 		 * Special check for XATTR/DIR_ITEM, as key->offset is name
615 		 * hash, should match its name
616 		 */
617 		if (key->type == BTRFS_DIR_ITEM_KEY ||
618 		    key->type == BTRFS_XATTR_ITEM_KEY) {
619 			char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)];
620 
621 			read_extent_buffer(leaf, namebuf,
622 					(unsigned long)(di + 1), name_len);
623 			name_hash = btrfs_name_hash(namebuf, name_len);
624 			if (unlikely(key->offset != name_hash)) {
625 				dir_item_err(leaf, slot,
626 		"name hash mismatch with key, have 0x%016x expect 0x%016llx",
627 					name_hash, key->offset);
628 				return -EUCLEAN;
629 			}
630 		}
631 		cur += total_size;
632 		di = (struct btrfs_dir_item *)((void *)di + total_size);
633 	}
634 	return 0;
635 }
636 
637 __printf(3, 4)
638 __cold
639 static void block_group_err(const struct extent_buffer *eb, int slot,
640 			    const char *fmt, ...)
641 {
642 	const struct btrfs_fs_info *fs_info = eb->fs_info;
643 	struct btrfs_key key;
644 	struct va_format vaf;
645 	va_list args;
646 
647 	btrfs_item_key_to_cpu(eb, &key, slot);
648 	va_start(args, fmt);
649 
650 	vaf.fmt = fmt;
651 	vaf.va = &args;
652 
653 	dump_page(folio_page(eb->folios[0], 0), "eb page dump");
654 	btrfs_crit(fs_info,
655 	"corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV",
656 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
657 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
658 		key.objectid, key.offset, &vaf);
659 	va_end(args);
660 }
661 
662 static int check_block_group_item(struct extent_buffer *leaf,
663 				  struct btrfs_key *key, int slot)
664 {
665 	struct btrfs_fs_info *fs_info = leaf->fs_info;
666 	struct btrfs_block_group_item bgi;
667 	u32 item_size = btrfs_item_size(leaf, slot);
668 	u64 chunk_objectid;
669 	u64 flags;
670 	u64 type;
671 
672 	/*
673 	 * Here we don't really care about alignment since extent allocator can
674 	 * handle it.  We care more about the size.
675 	 */
676 	if (unlikely(key->offset == 0)) {
677 		block_group_err(leaf, slot,
678 				"invalid block group size 0");
679 		return -EUCLEAN;
680 	}
681 
682 	if (unlikely(item_size != sizeof(bgi))) {
683 		block_group_err(leaf, slot,
684 			"invalid item size, have %u expect %zu",
685 				item_size, sizeof(bgi));
686 		return -EUCLEAN;
687 	}
688 
689 	read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
690 			   sizeof(bgi));
691 	chunk_objectid = btrfs_stack_block_group_chunk_objectid(&bgi);
692 	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
693 		/*
694 		 * We don't init the nr_global_roots until we load the global
695 		 * roots, so this could be 0 at mount time.  If it's 0 we'll
696 		 * just assume we're fine, and later we'll check against our
697 		 * actual value.
698 		 */
699 		if (unlikely(fs_info->nr_global_roots &&
700 			     chunk_objectid >= fs_info->nr_global_roots)) {
701 			block_group_err(leaf, slot,
702 	"invalid block group global root id, have %llu, needs to be <= %llu",
703 					chunk_objectid,
704 					fs_info->nr_global_roots);
705 			return -EUCLEAN;
706 		}
707 	} else if (unlikely(chunk_objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID)) {
708 		block_group_err(leaf, slot,
709 		"invalid block group chunk objectid, have %llu expect %llu",
710 				btrfs_stack_block_group_chunk_objectid(&bgi),
711 				BTRFS_FIRST_CHUNK_TREE_OBJECTID);
712 		return -EUCLEAN;
713 	}
714 
715 	if (unlikely(btrfs_stack_block_group_used(&bgi) > key->offset)) {
716 		block_group_err(leaf, slot,
717 			"invalid block group used, have %llu expect [0, %llu)",
718 				btrfs_stack_block_group_used(&bgi), key->offset);
719 		return -EUCLEAN;
720 	}
721 
722 	flags = btrfs_stack_block_group_flags(&bgi);
723 	if (unlikely(hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1)) {
724 		block_group_err(leaf, slot,
725 "invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set",
726 			flags & BTRFS_BLOCK_GROUP_PROFILE_MASK,
727 			hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK));
728 		return -EUCLEAN;
729 	}
730 
731 	type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
732 	if (unlikely(type != BTRFS_BLOCK_GROUP_DATA &&
733 		     type != BTRFS_BLOCK_GROUP_METADATA &&
734 		     type != BTRFS_BLOCK_GROUP_SYSTEM &&
735 		     type != (BTRFS_BLOCK_GROUP_METADATA |
736 			      BTRFS_BLOCK_GROUP_DATA))) {
737 		block_group_err(leaf, slot,
738 "invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx or 0x%llx",
739 			type, hweight64(type),
740 			BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
741 			BTRFS_BLOCK_GROUP_SYSTEM,
742 			BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA);
743 		return -EUCLEAN;
744 	}
745 	return 0;
746 }
747 
748 __printf(4, 5)
749 __cold
750 static void chunk_err(const struct extent_buffer *leaf,
751 		      const struct btrfs_chunk *chunk, u64 logical,
752 		      const char *fmt, ...)
753 {
754 	const struct btrfs_fs_info *fs_info = leaf->fs_info;
755 	bool is_sb;
756 	struct va_format vaf;
757 	va_list args;
758 	int i;
759 	int slot = -1;
760 
761 	/* Only superblock eb is able to have such small offset */
762 	is_sb = (leaf->start == BTRFS_SUPER_INFO_OFFSET);
763 
764 	if (!is_sb) {
765 		/*
766 		 * Get the slot number by iterating through all slots, this
767 		 * would provide better readability.
768 		 */
769 		for (i = 0; i < btrfs_header_nritems(leaf); i++) {
770 			if (btrfs_item_ptr_offset(leaf, i) ==
771 					(unsigned long)chunk) {
772 				slot = i;
773 				break;
774 			}
775 		}
776 	}
777 	va_start(args, fmt);
778 	vaf.fmt = fmt;
779 	vaf.va = &args;
780 
781 	if (is_sb)
782 		btrfs_crit(fs_info,
783 		"corrupt superblock syschunk array: chunk_start=%llu, %pV",
784 			   logical, &vaf);
785 	else
786 		btrfs_crit(fs_info,
787 	"corrupt leaf: root=%llu block=%llu slot=%d chunk_start=%llu, %pV",
788 			   BTRFS_CHUNK_TREE_OBJECTID, leaf->start, slot,
789 			   logical, &vaf);
790 	va_end(args);
791 }
792 
793 /*
794  * The common chunk check which could also work on super block sys chunk array.
795  *
796  * Return -EUCLEAN if anything is corrupted.
797  * Return 0 if everything is OK.
798  */
799 int btrfs_check_chunk_valid(struct extent_buffer *leaf,
800 			    struct btrfs_chunk *chunk, u64 logical)
801 {
802 	struct btrfs_fs_info *fs_info = leaf->fs_info;
803 	u64 length;
804 	u64 chunk_end;
805 	u64 stripe_len;
806 	u16 num_stripes;
807 	u16 sub_stripes;
808 	u64 type;
809 	u64 features;
810 	bool mixed = false;
811 	int raid_index;
812 	int nparity;
813 	int ncopies;
814 
815 	length = btrfs_chunk_length(leaf, chunk);
816 	stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
817 	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
818 	sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
819 	type = btrfs_chunk_type(leaf, chunk);
820 	raid_index = btrfs_bg_flags_to_raid_index(type);
821 	ncopies = btrfs_raid_array[raid_index].ncopies;
822 	nparity = btrfs_raid_array[raid_index].nparity;
823 
824 	if (unlikely(!num_stripes)) {
825 		chunk_err(leaf, chunk, logical,
826 			  "invalid chunk num_stripes, have %u", num_stripes);
827 		return -EUCLEAN;
828 	}
829 	if (unlikely(num_stripes < ncopies)) {
830 		chunk_err(leaf, chunk, logical,
831 			  "invalid chunk num_stripes < ncopies, have %u < %d",
832 			  num_stripes, ncopies);
833 		return -EUCLEAN;
834 	}
835 	if (unlikely(nparity && num_stripes == nparity)) {
836 		chunk_err(leaf, chunk, logical,
837 			  "invalid chunk num_stripes == nparity, have %u == %d",
838 			  num_stripes, nparity);
839 		return -EUCLEAN;
840 	}
841 	if (unlikely(!IS_ALIGNED(logical, fs_info->sectorsize))) {
842 		chunk_err(leaf, chunk, logical,
843 		"invalid chunk logical, have %llu should aligned to %u",
844 			  logical, fs_info->sectorsize);
845 		return -EUCLEAN;
846 	}
847 	if (unlikely(btrfs_chunk_sector_size(leaf, chunk) != fs_info->sectorsize)) {
848 		chunk_err(leaf, chunk, logical,
849 			  "invalid chunk sectorsize, have %u expect %u",
850 			  btrfs_chunk_sector_size(leaf, chunk),
851 			  fs_info->sectorsize);
852 		return -EUCLEAN;
853 	}
854 	if (unlikely(!length || !IS_ALIGNED(length, fs_info->sectorsize))) {
855 		chunk_err(leaf, chunk, logical,
856 			  "invalid chunk length, have %llu", length);
857 		return -EUCLEAN;
858 	}
859 	if (unlikely(check_add_overflow(logical, length, &chunk_end))) {
860 		chunk_err(leaf, chunk, logical,
861 "invalid chunk logical start and length, have logical start %llu length %llu",
862 			  logical, length);
863 		return -EUCLEAN;
864 	}
865 	if (unlikely(!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN)) {
866 		chunk_err(leaf, chunk, logical,
867 			  "invalid chunk stripe length: %llu",
868 			  stripe_len);
869 		return -EUCLEAN;
870 	}
871 	/*
872 	 * We artificially limit the chunk size, so that the number of stripes
873 	 * inside a chunk can be fit into a U32.  The current limit (256G) is
874 	 * way too large for real world usage anyway, and it's also much larger
875 	 * than our existing limit (10G).
876 	 *
877 	 * Thus it should be a good way to catch obvious bitflips.
878 	 */
879 	if (unlikely(length >= btrfs_stripe_nr_to_offset(U32_MAX))) {
880 		chunk_err(leaf, chunk, logical,
881 			  "chunk length too large: have %llu limit %llu",
882 			  length, btrfs_stripe_nr_to_offset(U32_MAX));
883 		return -EUCLEAN;
884 	}
885 	if (unlikely(type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
886 			      BTRFS_BLOCK_GROUP_PROFILE_MASK))) {
887 		chunk_err(leaf, chunk, logical,
888 			  "unrecognized chunk type: 0x%llx",
889 			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
890 			    BTRFS_BLOCK_GROUP_PROFILE_MASK) &
891 			  btrfs_chunk_type(leaf, chunk));
892 		return -EUCLEAN;
893 	}
894 
895 	if (unlikely(!has_single_bit_set(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
896 		     (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0)) {
897 		chunk_err(leaf, chunk, logical,
898 		"invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
899 			  type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
900 		return -EUCLEAN;
901 	}
902 	if (unlikely((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0)) {
903 		chunk_err(leaf, chunk, logical,
904 	"missing chunk type flag, have 0x%llx one bit must be set in 0x%llx",
905 			  type, BTRFS_BLOCK_GROUP_TYPE_MASK);
906 		return -EUCLEAN;
907 	}
908 
909 	if (unlikely((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
910 		     (type & (BTRFS_BLOCK_GROUP_METADATA |
911 			      BTRFS_BLOCK_GROUP_DATA)))) {
912 		chunk_err(leaf, chunk, logical,
913 			  "system chunk with data or metadata type: 0x%llx",
914 			  type);
915 		return -EUCLEAN;
916 	}
917 
918 	features = btrfs_super_incompat_flags(fs_info->super_copy);
919 	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
920 		mixed = true;
921 
922 	if (!mixed) {
923 		if (unlikely((type & BTRFS_BLOCK_GROUP_METADATA) &&
924 			     (type & BTRFS_BLOCK_GROUP_DATA))) {
925 			chunk_err(leaf, chunk, logical,
926 			"mixed chunk type in non-mixed mode: 0x%llx", type);
927 			return -EUCLEAN;
928 		}
929 	}
930 
931 	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 &&
932 		      sub_stripes != btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes) ||
933 		     (type & BTRFS_BLOCK_GROUP_RAID1 &&
934 		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1].devs_min) ||
935 		     (type & BTRFS_BLOCK_GROUP_RAID1C3 &&
936 		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C3].devs_min) ||
937 		     (type & BTRFS_BLOCK_GROUP_RAID1C4 &&
938 		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C4].devs_min) ||
939 		     (type & BTRFS_BLOCK_GROUP_RAID5 &&
940 		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID5].devs_min) ||
941 		     (type & BTRFS_BLOCK_GROUP_RAID6 &&
942 		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID6].devs_min) ||
943 		     (type & BTRFS_BLOCK_GROUP_DUP &&
944 		      num_stripes != btrfs_raid_array[BTRFS_RAID_DUP].dev_stripes) ||
945 		     ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
946 		      num_stripes != btrfs_raid_array[BTRFS_RAID_SINGLE].dev_stripes))) {
947 		chunk_err(leaf, chunk, logical,
948 			"invalid num_stripes:sub_stripes %u:%u for profile %llu",
949 			num_stripes, sub_stripes,
950 			type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
951 		return -EUCLEAN;
952 	}
953 
954 	return 0;
955 }
956 
957 /*
958  * Enhanced version of chunk item checker.
959  *
960  * The common btrfs_check_chunk_valid() doesn't check item size since it needs
961  * to work on super block sys_chunk_array which doesn't have full item ptr.
962  */
963 static int check_leaf_chunk_item(struct extent_buffer *leaf,
964 				 struct btrfs_chunk *chunk,
965 				 struct btrfs_key *key, int slot)
966 {
967 	int num_stripes;
968 
969 	if (unlikely(btrfs_item_size(leaf, slot) < sizeof(struct btrfs_chunk))) {
970 		chunk_err(leaf, chunk, key->offset,
971 			"invalid chunk item size: have %u expect [%zu, %u)",
972 			btrfs_item_size(leaf, slot),
973 			sizeof(struct btrfs_chunk),
974 			BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
975 		return -EUCLEAN;
976 	}
977 
978 	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
979 	/* Let btrfs_check_chunk_valid() handle this error type */
980 	if (num_stripes == 0)
981 		goto out;
982 
983 	if (unlikely(btrfs_chunk_item_size(num_stripes) !=
984 		     btrfs_item_size(leaf, slot))) {
985 		chunk_err(leaf, chunk, key->offset,
986 			"invalid chunk item size: have %u expect %lu",
987 			btrfs_item_size(leaf, slot),
988 			btrfs_chunk_item_size(num_stripes));
989 		return -EUCLEAN;
990 	}
991 out:
992 	return btrfs_check_chunk_valid(leaf, chunk, key->offset);
993 }
994 
995 __printf(3, 4)
996 __cold
997 static void dev_item_err(const struct extent_buffer *eb, int slot,
998 			 const char *fmt, ...)
999 {
1000 	struct btrfs_key key;
1001 	struct va_format vaf;
1002 	va_list args;
1003 
1004 	btrfs_item_key_to_cpu(eb, &key, slot);
1005 	va_start(args, fmt);
1006 
1007 	vaf.fmt = fmt;
1008 	vaf.va = &args;
1009 
1010 	dump_page(folio_page(eb->folios[0], 0), "eb page dump");
1011 	btrfs_crit(eb->fs_info,
1012 	"corrupt %s: root=%llu block=%llu slot=%d devid=%llu %pV",
1013 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
1014 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
1015 		key.objectid, &vaf);
1016 	va_end(args);
1017 }
1018 
1019 static int check_dev_item(struct extent_buffer *leaf,
1020 			  struct btrfs_key *key, int slot)
1021 {
1022 	struct btrfs_dev_item *ditem;
1023 	const u32 item_size = btrfs_item_size(leaf, slot);
1024 
1025 	if (unlikely(key->objectid != BTRFS_DEV_ITEMS_OBJECTID)) {
1026 		dev_item_err(leaf, slot,
1027 			     "invalid objectid: has=%llu expect=%llu",
1028 			     key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
1029 		return -EUCLEAN;
1030 	}
1031 
1032 	if (unlikely(item_size != sizeof(*ditem))) {
1033 		dev_item_err(leaf, slot, "invalid item size: has %u expect %zu",
1034 			     item_size, sizeof(*ditem));
1035 		return -EUCLEAN;
1036 	}
1037 
1038 	ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
1039 	if (unlikely(btrfs_device_id(leaf, ditem) != key->offset)) {
1040 		dev_item_err(leaf, slot,
1041 			     "devid mismatch: key has=%llu item has=%llu",
1042 			     key->offset, btrfs_device_id(leaf, ditem));
1043 		return -EUCLEAN;
1044 	}
1045 
1046 	/*
1047 	 * For device total_bytes, we don't have reliable way to check it, as
1048 	 * it can be 0 for device removal. Device size check can only be done
1049 	 * by dev extents check.
1050 	 */
1051 	if (unlikely(btrfs_device_bytes_used(leaf, ditem) >
1052 		     btrfs_device_total_bytes(leaf, ditem))) {
1053 		dev_item_err(leaf, slot,
1054 			     "invalid bytes used: have %llu expect [0, %llu]",
1055 			     btrfs_device_bytes_used(leaf, ditem),
1056 			     btrfs_device_total_bytes(leaf, ditem));
1057 		return -EUCLEAN;
1058 	}
1059 	/*
1060 	 * Remaining members like io_align/type/gen/dev_group aren't really
1061 	 * utilized.  Skip them to make later usage of them easier.
1062 	 */
1063 	return 0;
1064 }
1065 
1066 static int check_inode_item(struct extent_buffer *leaf,
1067 			    struct btrfs_key *key, int slot)
1068 {
1069 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1070 	struct btrfs_inode_item *iitem;
1071 	u64 super_gen = btrfs_super_generation(fs_info->super_copy);
1072 	u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
1073 	const u32 item_size = btrfs_item_size(leaf, slot);
1074 	u32 mode;
1075 	int ret;
1076 	u32 flags;
1077 	u32 ro_flags;
1078 
1079 	ret = check_inode_key(leaf, key, slot);
1080 	if (unlikely(ret < 0))
1081 		return ret;
1082 
1083 	if (unlikely(item_size != sizeof(*iitem))) {
1084 		generic_err(leaf, slot, "invalid item size: has %u expect %zu",
1085 			    item_size, sizeof(*iitem));
1086 		return -EUCLEAN;
1087 	}
1088 
1089 	iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);
1090 
1091 	/* Here we use super block generation + 1 to handle log tree */
1092 	if (unlikely(btrfs_inode_generation(leaf, iitem) > super_gen + 1)) {
1093 		inode_item_err(leaf, slot,
1094 			"invalid inode generation: has %llu expect (0, %llu]",
1095 			       btrfs_inode_generation(leaf, iitem),
1096 			       super_gen + 1);
1097 		return -EUCLEAN;
1098 	}
1099 	/* Note for ROOT_TREE_DIR_ITEM, mkfs could set its transid 0 */
1100 	if (unlikely(btrfs_inode_transid(leaf, iitem) > super_gen + 1)) {
1101 		inode_item_err(leaf, slot,
1102 			"invalid inode transid: has %llu expect [0, %llu]",
1103 			       btrfs_inode_transid(leaf, iitem), super_gen + 1);
1104 		return -EUCLEAN;
1105 	}
1106 
1107 	/*
1108 	 * For size and nbytes it's better not to be too strict, as for dir
1109 	 * item its size/nbytes can easily get wrong, but doesn't affect
1110 	 * anything in the fs. So here we skip the check.
1111 	 */
1112 	mode = btrfs_inode_mode(leaf, iitem);
1113 	if (unlikely(mode & ~valid_mask)) {
1114 		inode_item_err(leaf, slot,
1115 			       "unknown mode bit detected: 0x%x",
1116 			       mode & ~valid_mask);
1117 		return -EUCLEAN;
1118 	}
1119 
1120 	/*
1121 	 * S_IFMT is not bit mapped so we can't completely rely on
1122 	 * is_power_of_2/has_single_bit_set, but it can save us from checking
1123 	 * FIFO/CHR/DIR/REG.  Only needs to check BLK, LNK and SOCKS
1124 	 */
1125 	if (!has_single_bit_set(mode & S_IFMT)) {
1126 		if (unlikely(!S_ISLNK(mode) && !S_ISBLK(mode) && !S_ISSOCK(mode))) {
1127 			inode_item_err(leaf, slot,
1128 			"invalid mode: has 0%o expect valid S_IF* bit(s)",
1129 				       mode & S_IFMT);
1130 			return -EUCLEAN;
1131 		}
1132 	}
1133 	if (unlikely(S_ISDIR(mode) && btrfs_inode_nlink(leaf, iitem) > 1)) {
1134 		inode_item_err(leaf, slot,
1135 		       "invalid nlink: has %u expect no more than 1 for dir",
1136 			btrfs_inode_nlink(leaf, iitem));
1137 		return -EUCLEAN;
1138 	}
1139 	btrfs_inode_split_flags(btrfs_inode_flags(leaf, iitem), &flags, &ro_flags);
1140 	if (unlikely(flags & ~BTRFS_INODE_FLAG_MASK)) {
1141 		inode_item_err(leaf, slot,
1142 			       "unknown incompat flags detected: 0x%x", flags);
1143 		return -EUCLEAN;
1144 	}
1145 	if (unlikely(!sb_rdonly(fs_info->sb) &&
1146 		     (ro_flags & ~BTRFS_INODE_RO_FLAG_MASK))) {
1147 		inode_item_err(leaf, slot,
1148 			"unknown ro-compat flags detected on writeable mount: 0x%x",
1149 			ro_flags);
1150 		return -EUCLEAN;
1151 	}
1152 	return 0;
1153 }
1154 
1155 static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
1156 			   int slot)
1157 {
1158 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1159 	struct btrfs_root_item ri = { 0 };
1160 	const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY |
1161 				     BTRFS_ROOT_SUBVOL_DEAD;
1162 	int ret;
1163 
1164 	ret = check_root_key(leaf, key, slot);
1165 	if (unlikely(ret < 0))
1166 		return ret;
1167 
1168 	if (unlikely(btrfs_item_size(leaf, slot) != sizeof(ri) &&
1169 		     btrfs_item_size(leaf, slot) !=
1170 		     btrfs_legacy_root_item_size())) {
1171 		generic_err(leaf, slot,
1172 			    "invalid root item size, have %u expect %zu or %u",
1173 			    btrfs_item_size(leaf, slot), sizeof(ri),
1174 			    btrfs_legacy_root_item_size());
1175 		return -EUCLEAN;
1176 	}
1177 
1178 	/*
1179 	 * For legacy root item, the members starting at generation_v2 will be
1180 	 * all filled with 0.
1181 	 * And since we allow geneartion_v2 as 0, it will still pass the check.
1182 	 */
1183 	read_extent_buffer(leaf, &ri, btrfs_item_ptr_offset(leaf, slot),
1184 			   btrfs_item_size(leaf, slot));
1185 
1186 	/* Generation related */
1187 	if (unlikely(btrfs_root_generation(&ri) >
1188 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1189 		generic_err(leaf, slot,
1190 			"invalid root generation, have %llu expect (0, %llu]",
1191 			    btrfs_root_generation(&ri),
1192 			    btrfs_super_generation(fs_info->super_copy) + 1);
1193 		return -EUCLEAN;
1194 	}
1195 	if (unlikely(btrfs_root_generation_v2(&ri) >
1196 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1197 		generic_err(leaf, slot,
1198 		"invalid root v2 generation, have %llu expect (0, %llu]",
1199 			    btrfs_root_generation_v2(&ri),
1200 			    btrfs_super_generation(fs_info->super_copy) + 1);
1201 		return -EUCLEAN;
1202 	}
1203 	if (unlikely(btrfs_root_last_snapshot(&ri) >
1204 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1205 		generic_err(leaf, slot,
1206 		"invalid root last_snapshot, have %llu expect (0, %llu]",
1207 			    btrfs_root_last_snapshot(&ri),
1208 			    btrfs_super_generation(fs_info->super_copy) + 1);
1209 		return -EUCLEAN;
1210 	}
1211 
1212 	/* Alignment and level check */
1213 	if (unlikely(!IS_ALIGNED(btrfs_root_bytenr(&ri), fs_info->sectorsize))) {
1214 		generic_err(leaf, slot,
1215 		"invalid root bytenr, have %llu expect to be aligned to %u",
1216 			    btrfs_root_bytenr(&ri), fs_info->sectorsize);
1217 		return -EUCLEAN;
1218 	}
1219 	if (unlikely(btrfs_root_level(&ri) >= BTRFS_MAX_LEVEL)) {
1220 		generic_err(leaf, slot,
1221 			    "invalid root level, have %u expect [0, %u]",
1222 			    btrfs_root_level(&ri), BTRFS_MAX_LEVEL - 1);
1223 		return -EUCLEAN;
1224 	}
1225 	if (unlikely(btrfs_root_drop_level(&ri) >= BTRFS_MAX_LEVEL)) {
1226 		generic_err(leaf, slot,
1227 			    "invalid root level, have %u expect [0, %u]",
1228 			    btrfs_root_drop_level(&ri), BTRFS_MAX_LEVEL - 1);
1229 		return -EUCLEAN;
1230 	}
1231 
1232 	/* Flags check */
1233 	if (unlikely(btrfs_root_flags(&ri) & ~valid_root_flags)) {
1234 		generic_err(leaf, slot,
1235 			    "invalid root flags, have 0x%llx expect mask 0x%llx",
1236 			    btrfs_root_flags(&ri), valid_root_flags);
1237 		return -EUCLEAN;
1238 	}
1239 	return 0;
1240 }
1241 
1242 __printf(3,4)
1243 __cold
1244 static void extent_err(const struct extent_buffer *eb, int slot,
1245 		       const char *fmt, ...)
1246 {
1247 	struct btrfs_key key;
1248 	struct va_format vaf;
1249 	va_list args;
1250 	u64 bytenr;
1251 	u64 len;
1252 
1253 	btrfs_item_key_to_cpu(eb, &key, slot);
1254 	bytenr = key.objectid;
1255 	if (key.type == BTRFS_METADATA_ITEM_KEY ||
1256 	    key.type == BTRFS_TREE_BLOCK_REF_KEY ||
1257 	    key.type == BTRFS_SHARED_BLOCK_REF_KEY)
1258 		len = eb->fs_info->nodesize;
1259 	else
1260 		len = key.offset;
1261 	va_start(args, fmt);
1262 
1263 	vaf.fmt = fmt;
1264 	vaf.va = &args;
1265 
1266 	dump_page(folio_page(eb->folios[0], 0), "eb page dump");
1267 	btrfs_crit(eb->fs_info,
1268 	"corrupt %s: block=%llu slot=%d extent bytenr=%llu len=%llu %pV",
1269 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
1270 		eb->start, slot, bytenr, len, &vaf);
1271 	va_end(args);
1272 }
1273 
1274 static int check_extent_item(struct extent_buffer *leaf,
1275 			     struct btrfs_key *key, int slot,
1276 			     struct btrfs_key *prev_key)
1277 {
1278 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1279 	struct btrfs_extent_item *ei;
1280 	bool is_tree_block = false;
1281 	unsigned long ptr;	/* Current pointer inside inline refs */
1282 	unsigned long end;	/* Extent item end */
1283 	const u32 item_size = btrfs_item_size(leaf, slot);
1284 	u8 last_type = 0;
1285 	u64 last_seq = U64_MAX;
1286 	u64 flags;
1287 	u64 generation;
1288 	u64 total_refs;		/* Total refs in btrfs_extent_item */
1289 	u64 inline_refs = 0;	/* found total inline refs */
1290 
1291 	if (unlikely(key->type == BTRFS_METADATA_ITEM_KEY &&
1292 		     !btrfs_fs_incompat(fs_info, SKINNY_METADATA))) {
1293 		generic_err(leaf, slot,
1294 "invalid key type, METADATA_ITEM type invalid when SKINNY_METADATA feature disabled");
1295 		return -EUCLEAN;
1296 	}
1297 	/* key->objectid is the bytenr for both key types */
1298 	if (unlikely(!IS_ALIGNED(key->objectid, fs_info->sectorsize))) {
1299 		generic_err(leaf, slot,
1300 		"invalid key objectid, have %llu expect to be aligned to %u",
1301 			   key->objectid, fs_info->sectorsize);
1302 		return -EUCLEAN;
1303 	}
1304 
1305 	/* key->offset is tree level for METADATA_ITEM_KEY */
1306 	if (unlikely(key->type == BTRFS_METADATA_ITEM_KEY &&
1307 		     key->offset >= BTRFS_MAX_LEVEL)) {
1308 		extent_err(leaf, slot,
1309 			   "invalid tree level, have %llu expect [0, %u]",
1310 			   key->offset, BTRFS_MAX_LEVEL - 1);
1311 		return -EUCLEAN;
1312 	}
1313 
1314 	/*
1315 	 * EXTENT/METADATA_ITEM consists of:
1316 	 * 1) One btrfs_extent_item
1317 	 *    Records the total refs, type and generation of the extent.
1318 	 *
1319 	 * 2) One btrfs_tree_block_info (for EXTENT_ITEM and tree backref only)
1320 	 *    Records the first key and level of the tree block.
1321 	 *
1322 	 * 2) Zero or more btrfs_extent_inline_ref(s)
1323 	 *    Each inline ref has one btrfs_extent_inline_ref shows:
1324 	 *    2.1) The ref type, one of the 4
1325 	 *         TREE_BLOCK_REF	Tree block only
1326 	 *         SHARED_BLOCK_REF	Tree block only
1327 	 *         EXTENT_DATA_REF	Data only
1328 	 *         SHARED_DATA_REF	Data only
1329 	 *    2.2) Ref type specific data
1330 	 *         Either using btrfs_extent_inline_ref::offset, or specific
1331 	 *         data structure.
1332 	 *
1333 	 *    All above inline items should follow the order:
1334 	 *
1335 	 *    - All btrfs_extent_inline_ref::type should be in an ascending
1336 	 *      order
1337 	 *
1338 	 *    - Within the same type, the items should follow a descending
1339 	 *      order by their sequence number. The sequence number is
1340 	 *      determined by:
1341 	 *      * btrfs_extent_inline_ref::offset for all types  other than
1342 	 *        EXTENT_DATA_REF
1343 	 *      * hash_extent_data_ref() for EXTENT_DATA_REF
1344 	 */
1345 	if (unlikely(item_size < sizeof(*ei))) {
1346 		extent_err(leaf, slot,
1347 			   "invalid item size, have %u expect [%zu, %u)",
1348 			   item_size, sizeof(*ei),
1349 			   BTRFS_LEAF_DATA_SIZE(fs_info));
1350 		return -EUCLEAN;
1351 	}
1352 	end = item_size + btrfs_item_ptr_offset(leaf, slot);
1353 
1354 	/* Checks against extent_item */
1355 	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
1356 	flags = btrfs_extent_flags(leaf, ei);
1357 	total_refs = btrfs_extent_refs(leaf, ei);
1358 	generation = btrfs_extent_generation(leaf, ei);
1359 	if (unlikely(generation >
1360 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1361 		extent_err(leaf, slot,
1362 			   "invalid generation, have %llu expect (0, %llu]",
1363 			   generation,
1364 			   btrfs_super_generation(fs_info->super_copy) + 1);
1365 		return -EUCLEAN;
1366 	}
1367 	if (unlikely(!has_single_bit_set(flags & (BTRFS_EXTENT_FLAG_DATA |
1368 						  BTRFS_EXTENT_FLAG_TREE_BLOCK)))) {
1369 		extent_err(leaf, slot,
1370 		"invalid extent flag, have 0x%llx expect 1 bit set in 0x%llx",
1371 			flags, BTRFS_EXTENT_FLAG_DATA |
1372 			BTRFS_EXTENT_FLAG_TREE_BLOCK);
1373 		return -EUCLEAN;
1374 	}
1375 	is_tree_block = !!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK);
1376 	if (is_tree_block) {
1377 		if (unlikely(key->type == BTRFS_EXTENT_ITEM_KEY &&
1378 			     key->offset != fs_info->nodesize)) {
1379 			extent_err(leaf, slot,
1380 				   "invalid extent length, have %llu expect %u",
1381 				   key->offset, fs_info->nodesize);
1382 			return -EUCLEAN;
1383 		}
1384 	} else {
1385 		if (unlikely(key->type != BTRFS_EXTENT_ITEM_KEY)) {
1386 			extent_err(leaf, slot,
1387 			"invalid key type, have %u expect %u for data backref",
1388 				   key->type, BTRFS_EXTENT_ITEM_KEY);
1389 			return -EUCLEAN;
1390 		}
1391 		if (unlikely(!IS_ALIGNED(key->offset, fs_info->sectorsize))) {
1392 			extent_err(leaf, slot,
1393 			"invalid extent length, have %llu expect aligned to %u",
1394 				   key->offset, fs_info->sectorsize);
1395 			return -EUCLEAN;
1396 		}
1397 		if (unlikely(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
1398 			extent_err(leaf, slot,
1399 			"invalid extent flag, data has full backref set");
1400 			return -EUCLEAN;
1401 		}
1402 	}
1403 	ptr = (unsigned long)(struct btrfs_extent_item *)(ei + 1);
1404 
1405 	/* Check the special case of btrfs_tree_block_info */
1406 	if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
1407 		struct btrfs_tree_block_info *info;
1408 
1409 		info = (struct btrfs_tree_block_info *)ptr;
1410 		if (unlikely(btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL)) {
1411 			extent_err(leaf, slot,
1412 			"invalid tree block info level, have %u expect [0, %u]",
1413 				   btrfs_tree_block_level(leaf, info),
1414 				   BTRFS_MAX_LEVEL - 1);
1415 			return -EUCLEAN;
1416 		}
1417 		ptr = (unsigned long)(struct btrfs_tree_block_info *)(info + 1);
1418 	}
1419 
1420 	/* Check inline refs */
1421 	while (ptr < end) {
1422 		struct btrfs_extent_inline_ref *iref;
1423 		struct btrfs_extent_data_ref *dref;
1424 		struct btrfs_shared_data_ref *sref;
1425 		u64 seq;
1426 		u64 dref_offset;
1427 		u64 inline_offset;
1428 		u8 inline_type;
1429 
1430 		if (unlikely(ptr + sizeof(*iref) > end)) {
1431 			extent_err(leaf, slot,
1432 "inline ref item overflows extent item, ptr %lu iref size %zu end %lu",
1433 				   ptr, sizeof(*iref), end);
1434 			return -EUCLEAN;
1435 		}
1436 		iref = (struct btrfs_extent_inline_ref *)ptr;
1437 		inline_type = btrfs_extent_inline_ref_type(leaf, iref);
1438 		inline_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1439 		seq = inline_offset;
1440 		if (unlikely(ptr + btrfs_extent_inline_ref_size(inline_type) > end)) {
1441 			extent_err(leaf, slot,
1442 "inline ref item overflows extent item, ptr %lu iref size %u end %lu",
1443 				   ptr, btrfs_extent_inline_ref_size(inline_type), end);
1444 			return -EUCLEAN;
1445 		}
1446 
1447 		switch (inline_type) {
1448 		/* inline_offset is subvolid of the owner, no need to check */
1449 		case BTRFS_TREE_BLOCK_REF_KEY:
1450 			inline_refs++;
1451 			break;
1452 		/* Contains parent bytenr */
1453 		case BTRFS_SHARED_BLOCK_REF_KEY:
1454 			if (unlikely(!IS_ALIGNED(inline_offset,
1455 						 fs_info->sectorsize))) {
1456 				extent_err(leaf, slot,
1457 		"invalid tree parent bytenr, have %llu expect aligned to %u",
1458 					   inline_offset, fs_info->sectorsize);
1459 				return -EUCLEAN;
1460 			}
1461 			inline_refs++;
1462 			break;
1463 		/*
1464 		 * Contains owner subvolid, owner key objectid, adjusted offset.
1465 		 * The only obvious corruption can happen in that offset.
1466 		 */
1467 		case BTRFS_EXTENT_DATA_REF_KEY:
1468 			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1469 			dref_offset = btrfs_extent_data_ref_offset(leaf, dref);
1470 			seq = hash_extent_data_ref(
1471 					btrfs_extent_data_ref_root(leaf, dref),
1472 					btrfs_extent_data_ref_objectid(leaf, dref),
1473 					btrfs_extent_data_ref_offset(leaf, dref));
1474 			if (unlikely(!IS_ALIGNED(dref_offset,
1475 						 fs_info->sectorsize))) {
1476 				extent_err(leaf, slot,
1477 		"invalid data ref offset, have %llu expect aligned to %u",
1478 					   dref_offset, fs_info->sectorsize);
1479 				return -EUCLEAN;
1480 			}
1481 			inline_refs += btrfs_extent_data_ref_count(leaf, dref);
1482 			break;
1483 		/* Contains parent bytenr and ref count */
1484 		case BTRFS_SHARED_DATA_REF_KEY:
1485 			sref = (struct btrfs_shared_data_ref *)(iref + 1);
1486 			if (unlikely(!IS_ALIGNED(inline_offset,
1487 						 fs_info->sectorsize))) {
1488 				extent_err(leaf, slot,
1489 		"invalid data parent bytenr, have %llu expect aligned to %u",
1490 					   inline_offset, fs_info->sectorsize);
1491 				return -EUCLEAN;
1492 			}
1493 			inline_refs += btrfs_shared_data_ref_count(leaf, sref);
1494 			break;
1495 		case BTRFS_EXTENT_OWNER_REF_KEY:
1496 			WARN_ON(!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA));
1497 			break;
1498 		default:
1499 			extent_err(leaf, slot, "unknown inline ref type: %u",
1500 				   inline_type);
1501 			return -EUCLEAN;
1502 		}
1503 		if (inline_type < last_type) {
1504 			extent_err(leaf, slot,
1505 				   "inline ref out-of-order: has type %u, prev type %u",
1506 				   inline_type, last_type);
1507 			return -EUCLEAN;
1508 		}
1509 		/* Type changed, allow the sequence starts from U64_MAX again. */
1510 		if (inline_type > last_type)
1511 			last_seq = U64_MAX;
1512 		if (seq > last_seq) {
1513 			extent_err(leaf, slot,
1514 "inline ref out-of-order: has type %u offset %llu seq 0x%llx, prev type %u seq 0x%llx",
1515 				   inline_type, inline_offset, seq,
1516 				   last_type, last_seq);
1517 			return -EUCLEAN;
1518 		}
1519 		last_type = inline_type;
1520 		last_seq = seq;
1521 		ptr += btrfs_extent_inline_ref_size(inline_type);
1522 	}
1523 	/* No padding is allowed */
1524 	if (unlikely(ptr != end)) {
1525 		extent_err(leaf, slot,
1526 			   "invalid extent item size, padding bytes found");
1527 		return -EUCLEAN;
1528 	}
1529 
1530 	/* Finally, check the inline refs against total refs */
1531 	if (unlikely(inline_refs > total_refs)) {
1532 		extent_err(leaf, slot,
1533 			"invalid extent refs, have %llu expect >= inline %llu",
1534 			   total_refs, inline_refs);
1535 		return -EUCLEAN;
1536 	}
1537 
1538 	if ((prev_key->type == BTRFS_EXTENT_ITEM_KEY) ||
1539 	    (prev_key->type == BTRFS_METADATA_ITEM_KEY)) {
1540 		u64 prev_end = prev_key->objectid;
1541 
1542 		if (prev_key->type == BTRFS_METADATA_ITEM_KEY)
1543 			prev_end += fs_info->nodesize;
1544 		else
1545 			prev_end += prev_key->offset;
1546 
1547 		if (unlikely(prev_end > key->objectid)) {
1548 			extent_err(leaf, slot,
1549 	"previous extent [%llu %u %llu] overlaps current extent [%llu %u %llu]",
1550 				   prev_key->objectid, prev_key->type,
1551 				   prev_key->offset, key->objectid, key->type,
1552 				   key->offset);
1553 			return -EUCLEAN;
1554 		}
1555 	}
1556 
1557 	return 0;
1558 }
1559 
1560 static int check_simple_keyed_refs(struct extent_buffer *leaf,
1561 				   struct btrfs_key *key, int slot)
1562 {
1563 	u32 expect_item_size = 0;
1564 
1565 	if (key->type == BTRFS_SHARED_DATA_REF_KEY)
1566 		expect_item_size = sizeof(struct btrfs_shared_data_ref);
1567 
1568 	if (unlikely(btrfs_item_size(leaf, slot) != expect_item_size)) {
1569 		generic_err(leaf, slot,
1570 		"invalid item size, have %u expect %u for key type %u",
1571 			    btrfs_item_size(leaf, slot),
1572 			    expect_item_size, key->type);
1573 		return -EUCLEAN;
1574 	}
1575 	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
1576 		generic_err(leaf, slot,
1577 "invalid key objectid for shared block ref, have %llu expect aligned to %u",
1578 			    key->objectid, leaf->fs_info->sectorsize);
1579 		return -EUCLEAN;
1580 	}
1581 	if (unlikely(key->type != BTRFS_TREE_BLOCK_REF_KEY &&
1582 		     !IS_ALIGNED(key->offset, leaf->fs_info->sectorsize))) {
1583 		extent_err(leaf, slot,
1584 		"invalid tree parent bytenr, have %llu expect aligned to %u",
1585 			   key->offset, leaf->fs_info->sectorsize);
1586 		return -EUCLEAN;
1587 	}
1588 	return 0;
1589 }
1590 
1591 static int check_extent_data_ref(struct extent_buffer *leaf,
1592 				 struct btrfs_key *key, int slot)
1593 {
1594 	struct btrfs_extent_data_ref *dref;
1595 	unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);
1596 	const unsigned long end = ptr + btrfs_item_size(leaf, slot);
1597 
1598 	if (unlikely(btrfs_item_size(leaf, slot) % sizeof(*dref) != 0)) {
1599 		generic_err(leaf, slot,
1600 	"invalid item size, have %u expect aligned to %zu for key type %u",
1601 			    btrfs_item_size(leaf, slot),
1602 			    sizeof(*dref), key->type);
1603 		return -EUCLEAN;
1604 	}
1605 	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
1606 		generic_err(leaf, slot,
1607 "invalid key objectid for shared block ref, have %llu expect aligned to %u",
1608 			    key->objectid, leaf->fs_info->sectorsize);
1609 		return -EUCLEAN;
1610 	}
1611 	for (; ptr < end; ptr += sizeof(*dref)) {
1612 		u64 offset;
1613 
1614 		/*
1615 		 * We cannot check the extent_data_ref hash due to possible
1616 		 * overflow from the leaf due to hash collisions.
1617 		 */
1618 		dref = (struct btrfs_extent_data_ref *)ptr;
1619 		offset = btrfs_extent_data_ref_offset(leaf, dref);
1620 		if (unlikely(!IS_ALIGNED(offset, leaf->fs_info->sectorsize))) {
1621 			extent_err(leaf, slot,
1622 	"invalid extent data backref offset, have %llu expect aligned to %u",
1623 				   offset, leaf->fs_info->sectorsize);
1624 			return -EUCLEAN;
1625 		}
1626 	}
1627 	return 0;
1628 }
1629 
1630 #define inode_ref_err(eb, slot, fmt, args...)			\
1631 	inode_item_err(eb, slot, fmt, ##args)
1632 static int check_inode_ref(struct extent_buffer *leaf,
1633 			   struct btrfs_key *key, struct btrfs_key *prev_key,
1634 			   int slot)
1635 {
1636 	struct btrfs_inode_ref *iref;
1637 	unsigned long ptr;
1638 	unsigned long end;
1639 
1640 	if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
1641 		return -EUCLEAN;
1642 	/* namelen can't be 0, so item_size == sizeof() is also invalid */
1643 	if (unlikely(btrfs_item_size(leaf, slot) <= sizeof(*iref))) {
1644 		inode_ref_err(leaf, slot,
1645 			"invalid item size, have %u expect (%zu, %u)",
1646 			btrfs_item_size(leaf, slot),
1647 			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
1648 		return -EUCLEAN;
1649 	}
1650 
1651 	ptr = btrfs_item_ptr_offset(leaf, slot);
1652 	end = ptr + btrfs_item_size(leaf, slot);
1653 	while (ptr < end) {
1654 		u16 namelen;
1655 
1656 		if (unlikely(ptr + sizeof(iref) > end)) {
1657 			inode_ref_err(leaf, slot,
1658 			"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
1659 				ptr, end, sizeof(iref));
1660 			return -EUCLEAN;
1661 		}
1662 
1663 		iref = (struct btrfs_inode_ref *)ptr;
1664 		namelen = btrfs_inode_ref_name_len(leaf, iref);
1665 		if (unlikely(ptr + sizeof(*iref) + namelen > end)) {
1666 			inode_ref_err(leaf, slot,
1667 				"inode ref overflow, ptr %lu end %lu namelen %u",
1668 				ptr, end, namelen);
1669 			return -EUCLEAN;
1670 		}
1671 
1672 		/*
1673 		 * NOTE: In theory we should record all found index numbers
1674 		 * to find any duplicated indexes, but that will be too time
1675 		 * consuming for inodes with too many hard links.
1676 		 */
1677 		ptr += sizeof(*iref) + namelen;
1678 	}
1679 	return 0;
1680 }
1681 
1682 static int check_raid_stripe_extent(const struct extent_buffer *leaf,
1683 				    const struct btrfs_key *key, int slot)
1684 {
1685 	struct btrfs_stripe_extent *stripe_extent =
1686 		btrfs_item_ptr(leaf, slot, struct btrfs_stripe_extent);
1687 
1688 	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
1689 		generic_err(leaf, slot,
1690 "invalid key objectid for raid stripe extent, have %llu expect aligned to %u",
1691 			    key->objectid, leaf->fs_info->sectorsize);
1692 		return -EUCLEAN;
1693 	}
1694 
1695 	if (unlikely(!btrfs_fs_incompat(leaf->fs_info, RAID_STRIPE_TREE))) {
1696 		generic_err(leaf, slot,
1697 	"RAID_STRIPE_EXTENT present but RAID_STRIPE_TREE incompat bit unset");
1698 		return -EUCLEAN;
1699 	}
1700 
1701 	switch (btrfs_stripe_extent_encoding(leaf, stripe_extent)) {
1702 	case BTRFS_STRIPE_RAID0:
1703 	case BTRFS_STRIPE_RAID1:
1704 	case BTRFS_STRIPE_DUP:
1705 	case BTRFS_STRIPE_RAID10:
1706 	case BTRFS_STRIPE_RAID5:
1707 	case BTRFS_STRIPE_RAID6:
1708 	case BTRFS_STRIPE_RAID1C3:
1709 	case BTRFS_STRIPE_RAID1C4:
1710 		break;
1711 	default:
1712 		generic_err(leaf, slot, "invalid raid stripe encoding %u",
1713 			    btrfs_stripe_extent_encoding(leaf, stripe_extent));
1714 		return -EUCLEAN;
1715 	}
1716 
1717 	return 0;
1718 }
1719 
1720 /*
1721  * Common point to switch the item-specific validation.
1722  */
1723 static enum btrfs_tree_block_status check_leaf_item(struct extent_buffer *leaf,
1724 						    struct btrfs_key *key,
1725 						    int slot,
1726 						    struct btrfs_key *prev_key)
1727 {
1728 	int ret = 0;
1729 	struct btrfs_chunk *chunk;
1730 
1731 	switch (key->type) {
1732 	case BTRFS_EXTENT_DATA_KEY:
1733 		ret = check_extent_data_item(leaf, key, slot, prev_key);
1734 		break;
1735 	case BTRFS_EXTENT_CSUM_KEY:
1736 		ret = check_csum_item(leaf, key, slot, prev_key);
1737 		break;
1738 	case BTRFS_DIR_ITEM_KEY:
1739 	case BTRFS_DIR_INDEX_KEY:
1740 	case BTRFS_XATTR_ITEM_KEY:
1741 		ret = check_dir_item(leaf, key, prev_key, slot);
1742 		break;
1743 	case BTRFS_INODE_REF_KEY:
1744 		ret = check_inode_ref(leaf, key, prev_key, slot);
1745 		break;
1746 	case BTRFS_BLOCK_GROUP_ITEM_KEY:
1747 		ret = check_block_group_item(leaf, key, slot);
1748 		break;
1749 	case BTRFS_CHUNK_ITEM_KEY:
1750 		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1751 		ret = check_leaf_chunk_item(leaf, chunk, key, slot);
1752 		break;
1753 	case BTRFS_DEV_ITEM_KEY:
1754 		ret = check_dev_item(leaf, key, slot);
1755 		break;
1756 	case BTRFS_INODE_ITEM_KEY:
1757 		ret = check_inode_item(leaf, key, slot);
1758 		break;
1759 	case BTRFS_ROOT_ITEM_KEY:
1760 		ret = check_root_item(leaf, key, slot);
1761 		break;
1762 	case BTRFS_EXTENT_ITEM_KEY:
1763 	case BTRFS_METADATA_ITEM_KEY:
1764 		ret = check_extent_item(leaf, key, slot, prev_key);
1765 		break;
1766 	case BTRFS_TREE_BLOCK_REF_KEY:
1767 	case BTRFS_SHARED_DATA_REF_KEY:
1768 	case BTRFS_SHARED_BLOCK_REF_KEY:
1769 		ret = check_simple_keyed_refs(leaf, key, slot);
1770 		break;
1771 	case BTRFS_EXTENT_DATA_REF_KEY:
1772 		ret = check_extent_data_ref(leaf, key, slot);
1773 		break;
1774 	case BTRFS_RAID_STRIPE_KEY:
1775 		ret = check_raid_stripe_extent(leaf, key, slot);
1776 		break;
1777 	}
1778 
1779 	if (ret)
1780 		return BTRFS_TREE_BLOCK_INVALID_ITEM;
1781 	return BTRFS_TREE_BLOCK_CLEAN;
1782 }
1783 
1784 enum btrfs_tree_block_status __btrfs_check_leaf(struct extent_buffer *leaf)
1785 {
1786 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1787 	/* No valid key type is 0, so all key should be larger than this key */
1788 	struct btrfs_key prev_key = {0, 0, 0};
1789 	struct btrfs_key key;
1790 	u32 nritems = btrfs_header_nritems(leaf);
1791 	int slot;
1792 
1793 	if (unlikely(btrfs_header_level(leaf) != 0)) {
1794 		generic_err(leaf, 0,
1795 			"invalid level for leaf, have %d expect 0",
1796 			btrfs_header_level(leaf));
1797 		return BTRFS_TREE_BLOCK_INVALID_LEVEL;
1798 	}
1799 
1800 	if (unlikely(!btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_WRITTEN))) {
1801 		generic_err(leaf, 0, "invalid flag for leaf, WRITTEN not set");
1802 		return BTRFS_TREE_BLOCK_WRITTEN_NOT_SET;
1803 	}
1804 
1805 	/*
1806 	 * Extent buffers from a relocation tree have a owner field that
1807 	 * corresponds to the subvolume tree they are based on. So just from an
1808 	 * extent buffer alone we can not find out what is the id of the
1809 	 * corresponding subvolume tree, so we can not figure out if the extent
1810 	 * buffer corresponds to the root of the relocation tree or not. So
1811 	 * skip this check for relocation trees.
1812 	 */
1813 	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
1814 		u64 owner = btrfs_header_owner(leaf);
1815 
1816 		/* These trees must never be empty */
1817 		if (unlikely(owner == BTRFS_ROOT_TREE_OBJECTID ||
1818 			     owner == BTRFS_CHUNK_TREE_OBJECTID ||
1819 			     owner == BTRFS_DEV_TREE_OBJECTID ||
1820 			     owner == BTRFS_FS_TREE_OBJECTID ||
1821 			     owner == BTRFS_DATA_RELOC_TREE_OBJECTID)) {
1822 			generic_err(leaf, 0,
1823 			"invalid root, root %llu must never be empty",
1824 				    owner);
1825 			return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
1826 		}
1827 
1828 		/* Unknown tree */
1829 		if (unlikely(owner == 0)) {
1830 			generic_err(leaf, 0,
1831 				"invalid owner, root 0 is not defined");
1832 			return BTRFS_TREE_BLOCK_INVALID_OWNER;
1833 		}
1834 
1835 		/* EXTENT_TREE_V2 can have empty extent trees. */
1836 		if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
1837 			return BTRFS_TREE_BLOCK_CLEAN;
1838 
1839 		if (unlikely(owner == BTRFS_EXTENT_TREE_OBJECTID)) {
1840 			generic_err(leaf, 0,
1841 			"invalid root, root %llu must never be empty",
1842 				    owner);
1843 			return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
1844 		}
1845 
1846 		return BTRFS_TREE_BLOCK_CLEAN;
1847 	}
1848 
1849 	if (unlikely(nritems == 0))
1850 		return BTRFS_TREE_BLOCK_CLEAN;
1851 
1852 	/*
1853 	 * Check the following things to make sure this is a good leaf, and
1854 	 * leaf users won't need to bother with similar sanity checks:
1855 	 *
1856 	 * 1) key ordering
1857 	 * 2) item offset and size
1858 	 *    No overlap, no hole, all inside the leaf.
1859 	 * 3) item content
1860 	 *    If possible, do comprehensive sanity check.
1861 	 *    NOTE: All checks must only rely on the item data itself.
1862 	 */
1863 	for (slot = 0; slot < nritems; slot++) {
1864 		u32 item_end_expected;
1865 		u64 item_data_end;
1866 		enum btrfs_tree_block_status ret;
1867 
1868 		btrfs_item_key_to_cpu(leaf, &key, slot);
1869 
1870 		/* Make sure the keys are in the right order */
1871 		if (unlikely(btrfs_comp_cpu_keys(&prev_key, &key) >= 0)) {
1872 			generic_err(leaf, slot,
1873 	"bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
1874 				prev_key.objectid, prev_key.type,
1875 				prev_key.offset, key.objectid, key.type,
1876 				key.offset);
1877 			return BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
1878 		}
1879 
1880 		item_data_end = (u64)btrfs_item_offset(leaf, slot) +
1881 				btrfs_item_size(leaf, slot);
1882 		/*
1883 		 * Make sure the offset and ends are right, remember that the
1884 		 * item data starts at the end of the leaf and grows towards the
1885 		 * front.
1886 		 */
1887 		if (slot == 0)
1888 			item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
1889 		else
1890 			item_end_expected = btrfs_item_offset(leaf,
1891 								 slot - 1);
1892 		if (unlikely(item_data_end != item_end_expected)) {
1893 			generic_err(leaf, slot,
1894 				"unexpected item end, have %llu expect %u",
1895 				item_data_end, item_end_expected);
1896 			return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
1897 		}
1898 
1899 		/*
1900 		 * Check to make sure that we don't point outside of the leaf,
1901 		 * just in case all the items are consistent to each other, but
1902 		 * all point outside of the leaf.
1903 		 */
1904 		if (unlikely(item_data_end > BTRFS_LEAF_DATA_SIZE(fs_info))) {
1905 			generic_err(leaf, slot,
1906 			"slot end outside of leaf, have %llu expect range [0, %u]",
1907 				item_data_end, BTRFS_LEAF_DATA_SIZE(fs_info));
1908 			return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
1909 		}
1910 
1911 		/* Also check if the item pointer overlaps with btrfs item. */
1912 		if (unlikely(btrfs_item_ptr_offset(leaf, slot) <
1913 			     btrfs_item_nr_offset(leaf, slot) + sizeof(struct btrfs_item))) {
1914 			generic_err(leaf, slot,
1915 		"slot overlaps with its data, item end %lu data start %lu",
1916 				btrfs_item_nr_offset(leaf, slot) +
1917 				sizeof(struct btrfs_item),
1918 				btrfs_item_ptr_offset(leaf, slot));
1919 			return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
1920 		}
1921 
1922 		/* Check if the item size and content meet other criteria. */
1923 		ret = check_leaf_item(leaf, &key, slot, &prev_key);
1924 		if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
1925 			return ret;
1926 
1927 		prev_key.objectid = key.objectid;
1928 		prev_key.type = key.type;
1929 		prev_key.offset = key.offset;
1930 	}
1931 
1932 	return BTRFS_TREE_BLOCK_CLEAN;
1933 }
1934 
1935 int btrfs_check_leaf(struct extent_buffer *leaf)
1936 {
1937 	enum btrfs_tree_block_status ret;
1938 
1939 	ret = __btrfs_check_leaf(leaf);
1940 	if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
1941 		return -EUCLEAN;
1942 	return 0;
1943 }
1944 ALLOW_ERROR_INJECTION(btrfs_check_leaf, ERRNO);
1945 
1946 enum btrfs_tree_block_status __btrfs_check_node(struct extent_buffer *node)
1947 {
1948 	struct btrfs_fs_info *fs_info = node->fs_info;
1949 	unsigned long nr = btrfs_header_nritems(node);
1950 	struct btrfs_key key, next_key;
1951 	int slot;
1952 	int level = btrfs_header_level(node);
1953 	u64 bytenr;
1954 
1955 	if (unlikely(!btrfs_header_flag(node, BTRFS_HEADER_FLAG_WRITTEN))) {
1956 		generic_err(node, 0, "invalid flag for node, WRITTEN not set");
1957 		return BTRFS_TREE_BLOCK_WRITTEN_NOT_SET;
1958 	}
1959 
1960 	if (unlikely(level <= 0 || level >= BTRFS_MAX_LEVEL)) {
1961 		generic_err(node, 0,
1962 			"invalid level for node, have %d expect [1, %d]",
1963 			level, BTRFS_MAX_LEVEL - 1);
1964 		return BTRFS_TREE_BLOCK_INVALID_LEVEL;
1965 	}
1966 	if (unlikely(nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info))) {
1967 		btrfs_crit(fs_info,
1968 "corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
1969 			   btrfs_header_owner(node), node->start,
1970 			   nr == 0 ? "small" : "large", nr,
1971 			   BTRFS_NODEPTRS_PER_BLOCK(fs_info));
1972 		return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
1973 	}
1974 
1975 	for (slot = 0; slot < nr - 1; slot++) {
1976 		bytenr = btrfs_node_blockptr(node, slot);
1977 		btrfs_node_key_to_cpu(node, &key, slot);
1978 		btrfs_node_key_to_cpu(node, &next_key, slot + 1);
1979 
1980 		if (unlikely(!bytenr)) {
1981 			generic_err(node, slot,
1982 				"invalid NULL node pointer");
1983 			return BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
1984 		}
1985 		if (unlikely(!IS_ALIGNED(bytenr, fs_info->sectorsize))) {
1986 			generic_err(node, slot,
1987 			"unaligned pointer, have %llu should be aligned to %u",
1988 				bytenr, fs_info->sectorsize);
1989 			return BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
1990 		}
1991 
1992 		if (unlikely(btrfs_comp_cpu_keys(&key, &next_key) >= 0)) {
1993 			generic_err(node, slot,
1994 	"bad key order, current (%llu %u %llu) next (%llu %u %llu)",
1995 				key.objectid, key.type, key.offset,
1996 				next_key.objectid, next_key.type,
1997 				next_key.offset);
1998 			return BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
1999 		}
2000 	}
2001 	return BTRFS_TREE_BLOCK_CLEAN;
2002 }
2003 
2004 int btrfs_check_node(struct extent_buffer *node)
2005 {
2006 	enum btrfs_tree_block_status ret;
2007 
2008 	ret = __btrfs_check_node(node);
2009 	if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
2010 		return -EUCLEAN;
2011 	return 0;
2012 }
2013 ALLOW_ERROR_INJECTION(btrfs_check_node, ERRNO);
2014 
2015 int btrfs_check_eb_owner(const struct extent_buffer *eb, u64 root_owner)
2016 {
2017 	const bool is_subvol = is_fstree(root_owner);
2018 	const u64 eb_owner = btrfs_header_owner(eb);
2019 
2020 	/*
2021 	 * Skip dummy fs, as selftests don't create unique ebs for each dummy
2022 	 * root.
2023 	 */
2024 	if (btrfs_is_testing(eb->fs_info))
2025 		return 0;
2026 	/*
2027 	 * There are several call sites (backref walking, qgroup, and data
2028 	 * reloc) passing 0 as @root_owner, as they are not holding the
2029 	 * tree root.  In that case, we can not do a reliable ownership check,
2030 	 * so just exit.
2031 	 */
2032 	if (root_owner == 0)
2033 		return 0;
2034 	/*
2035 	 * These trees use key.offset as their owner, our callers don't have
2036 	 * the extra capacity to pass key.offset here.  So we just skip them.
2037 	 */
2038 	if (root_owner == BTRFS_TREE_LOG_OBJECTID ||
2039 	    root_owner == BTRFS_TREE_RELOC_OBJECTID)
2040 		return 0;
2041 
2042 	if (!is_subvol) {
2043 		/* For non-subvolume trees, the eb owner should match root owner */
2044 		if (unlikely(root_owner != eb_owner)) {
2045 			btrfs_crit(eb->fs_info,
2046 "corrupted %s, root=%llu block=%llu owner mismatch, have %llu expect %llu",
2047 				btrfs_header_level(eb) == 0 ? "leaf" : "node",
2048 				root_owner, btrfs_header_bytenr(eb), eb_owner,
2049 				root_owner);
2050 			return -EUCLEAN;
2051 		}
2052 		return 0;
2053 	}
2054 
2055 	/*
2056 	 * For subvolume trees, owners can mismatch, but they should all belong
2057 	 * to subvolume trees.
2058 	 */
2059 	if (unlikely(is_subvol != is_fstree(eb_owner))) {
2060 		btrfs_crit(eb->fs_info,
2061 "corrupted %s, root=%llu block=%llu owner mismatch, have %llu expect [%llu, %llu]",
2062 			btrfs_header_level(eb) == 0 ? "leaf" : "node",
2063 			root_owner, btrfs_header_bytenr(eb), eb_owner,
2064 			BTRFS_FIRST_FREE_OBJECTID, BTRFS_LAST_FREE_OBJECTID);
2065 		return -EUCLEAN;
2066 	}
2067 	return 0;
2068 }
2069 
2070 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
2071 			   struct btrfs_key *first_key, u64 parent_transid)
2072 {
2073 	struct btrfs_fs_info *fs_info = eb->fs_info;
2074 	int found_level;
2075 	struct btrfs_key found_key;
2076 	int ret;
2077 
2078 	found_level = btrfs_header_level(eb);
2079 	if (found_level != level) {
2080 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
2081 		     KERN_ERR "BTRFS: tree level check failed\n");
2082 		btrfs_err(fs_info,
2083 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
2084 			  eb->start, level, found_level);
2085 		return -EIO;
2086 	}
2087 
2088 	if (!first_key)
2089 		return 0;
2090 
2091 	/*
2092 	 * For live tree block (new tree blocks in current transaction),
2093 	 * we need proper lock context to avoid race, which is impossible here.
2094 	 * So we only checks tree blocks which is read from disk, whose
2095 	 * generation <= fs_info->last_trans_committed.
2096 	 */
2097 	if (btrfs_header_generation(eb) > btrfs_get_last_trans_committed(fs_info))
2098 		return 0;
2099 
2100 	/* We have @first_key, so this @eb must have at least one item */
2101 	if (btrfs_header_nritems(eb) == 0) {
2102 		btrfs_err(fs_info,
2103 		"invalid tree nritems, bytenr=%llu nritems=0 expect >0",
2104 			  eb->start);
2105 		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
2106 		return -EUCLEAN;
2107 	}
2108 
2109 	if (found_level)
2110 		btrfs_node_key_to_cpu(eb, &found_key, 0);
2111 	else
2112 		btrfs_item_key_to_cpu(eb, &found_key, 0);
2113 	ret = btrfs_comp_cpu_keys(first_key, &found_key);
2114 
2115 	if (ret) {
2116 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
2117 		     KERN_ERR "BTRFS: tree first key check failed\n");
2118 		btrfs_err(fs_info,
2119 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
2120 			  eb->start, parent_transid, first_key->objectid,
2121 			  first_key->type, first_key->offset,
2122 			  found_key.objectid, found_key.type,
2123 			  found_key.offset);
2124 	}
2125 	return ret;
2126 }
2127