xref: /linux/fs/btrfs/tree-checker.c (revision 1b0975ee3bdd3eb19a47371c26fd7ef8f7f6b599)
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 "disk-io.h"
25 #include "compression.h"
26 #include "volumes.h"
27 #include "misc.h"
28 #include "fs.h"
29 #include "accessors.h"
30 #include "file-item.h"
31 #include "inode-item.h"
32 
33 /*
34  * Error message should follow the following format:
35  * corrupt <type>: <identifier>, <reason>[, <bad_value>]
36  *
37  * @type:	leaf or node
38  * @identifier:	the necessary info to locate the leaf/node.
39  * 		It's recommended to decode key.objecitd/offset if it's
40  * 		meaningful.
41  * @reason:	describe the error
42  * @bad_value:	optional, it's recommended to output bad value and its
43  *		expected value (range).
44  *
45  * Since comma is used to separate the components, only space is allowed
46  * inside each component.
47  */
48 
49 /*
50  * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
51  * Allows callers to customize the output.
52  */
53 __printf(3, 4)
54 __cold
55 static void generic_err(const struct extent_buffer *eb, int slot,
56 			const char *fmt, ...)
57 {
58 	const struct btrfs_fs_info *fs_info = eb->fs_info;
59 	struct va_format vaf;
60 	va_list args;
61 
62 	va_start(args, fmt);
63 
64 	vaf.fmt = fmt;
65 	vaf.va = &args;
66 
67 	btrfs_crit(fs_info,
68 		"corrupt %s: root=%llu block=%llu slot=%d, %pV",
69 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
70 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, &vaf);
71 	va_end(args);
72 }
73 
74 /*
75  * Customized reporter for extent data item, since its key objectid and
76  * offset has its own meaning.
77  */
78 __printf(3, 4)
79 __cold
80 static void file_extent_err(const struct extent_buffer *eb, int slot,
81 			    const char *fmt, ...)
82 {
83 	const struct btrfs_fs_info *fs_info = eb->fs_info;
84 	struct btrfs_key key;
85 	struct va_format vaf;
86 	va_list args;
87 
88 	btrfs_item_key_to_cpu(eb, &key, slot);
89 	va_start(args, fmt);
90 
91 	vaf.fmt = fmt;
92 	vaf.va = &args;
93 
94 	btrfs_crit(fs_info,
95 	"corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
96 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
97 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
98 		key.objectid, key.offset, &vaf);
99 	va_end(args);
100 }
101 
102 /*
103  * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
104  * Else return 1
105  */
106 #define CHECK_FE_ALIGNED(leaf, slot, fi, name, alignment)		      \
107 ({									      \
108 	if (unlikely(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)),      \
109 				 (alignment))))				      \
110 		file_extent_err((leaf), (slot),				      \
111 	"invalid %s for file extent, have %llu, should be aligned to %u",     \
112 			(#name), btrfs_file_extent_##name((leaf), (fi)),      \
113 			(alignment));					      \
114 	(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment)));   \
115 })
116 
117 static u64 file_extent_end(struct extent_buffer *leaf,
118 			   struct btrfs_key *key,
119 			   struct btrfs_file_extent_item *extent)
120 {
121 	u64 end;
122 	u64 len;
123 
124 	if (btrfs_file_extent_type(leaf, extent) == BTRFS_FILE_EXTENT_INLINE) {
125 		len = btrfs_file_extent_ram_bytes(leaf, extent);
126 		end = ALIGN(key->offset + len, leaf->fs_info->sectorsize);
127 	} else {
128 		len = btrfs_file_extent_num_bytes(leaf, extent);
129 		end = key->offset + len;
130 	}
131 	return end;
132 }
133 
134 /*
135  * Customized report for dir_item, the only new important information is
136  * key->objectid, which represents inode number
137  */
138 __printf(3, 4)
139 __cold
140 static void dir_item_err(const struct extent_buffer *eb, int slot,
141 			 const char *fmt, ...)
142 {
143 	const struct btrfs_fs_info *fs_info = eb->fs_info;
144 	struct btrfs_key key;
145 	struct va_format vaf;
146 	va_list args;
147 
148 	btrfs_item_key_to_cpu(eb, &key, slot);
149 	va_start(args, fmt);
150 
151 	vaf.fmt = fmt;
152 	vaf.va = &args;
153 
154 	btrfs_crit(fs_info,
155 		"corrupt %s: root=%llu block=%llu slot=%d ino=%llu, %pV",
156 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
157 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
158 		key.objectid, &vaf);
159 	va_end(args);
160 }
161 
162 /*
163  * This functions checks prev_key->objectid, to ensure current key and prev_key
164  * share the same objectid as inode number.
165  *
166  * This is to detect missing INODE_ITEM in subvolume trees.
167  *
168  * Return true if everything is OK or we don't need to check.
169  * Return false if anything is wrong.
170  */
171 static bool check_prev_ino(struct extent_buffer *leaf,
172 			   struct btrfs_key *key, int slot,
173 			   struct btrfs_key *prev_key)
174 {
175 	/* No prev key, skip check */
176 	if (slot == 0)
177 		return true;
178 
179 	/* Only these key->types needs to be checked */
180 	ASSERT(key->type == BTRFS_XATTR_ITEM_KEY ||
181 	       key->type == BTRFS_INODE_REF_KEY ||
182 	       key->type == BTRFS_DIR_INDEX_KEY ||
183 	       key->type == BTRFS_DIR_ITEM_KEY ||
184 	       key->type == BTRFS_EXTENT_DATA_KEY);
185 
186 	/*
187 	 * Only subvolume trees along with their reloc trees need this check.
188 	 * Things like log tree doesn't follow this ino requirement.
189 	 */
190 	if (!is_fstree(btrfs_header_owner(leaf)))
191 		return true;
192 
193 	if (key->objectid == prev_key->objectid)
194 		return true;
195 
196 	/* Error found */
197 	dir_item_err(leaf, slot,
198 		"invalid previous key objectid, have %llu expect %llu",
199 		prev_key->objectid, key->objectid);
200 	return false;
201 }
202 static int check_extent_data_item(struct extent_buffer *leaf,
203 				  struct btrfs_key *key, int slot,
204 				  struct btrfs_key *prev_key)
205 {
206 	struct btrfs_fs_info *fs_info = leaf->fs_info;
207 	struct btrfs_file_extent_item *fi;
208 	u32 sectorsize = fs_info->sectorsize;
209 	u32 item_size = btrfs_item_size(leaf, slot);
210 	u64 extent_end;
211 
212 	if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
213 		file_extent_err(leaf, slot,
214 "unaligned file_offset for file extent, have %llu should be aligned to %u",
215 			key->offset, sectorsize);
216 		return -EUCLEAN;
217 	}
218 
219 	/*
220 	 * Previous key must have the same key->objectid (ino).
221 	 * It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
222 	 * But if objectids mismatch, it means we have a missing
223 	 * INODE_ITEM.
224 	 */
225 	if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
226 		return -EUCLEAN;
227 
228 	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
229 
230 	/*
231 	 * Make sure the item contains at least inline header, so the file
232 	 * extent type is not some garbage.
233 	 */
234 	if (unlikely(item_size < BTRFS_FILE_EXTENT_INLINE_DATA_START)) {
235 		file_extent_err(leaf, slot,
236 				"invalid item size, have %u expect [%zu, %u)",
237 				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START,
238 				SZ_4K);
239 		return -EUCLEAN;
240 	}
241 	if (unlikely(btrfs_file_extent_type(leaf, fi) >=
242 		     BTRFS_NR_FILE_EXTENT_TYPES)) {
243 		file_extent_err(leaf, slot,
244 		"invalid type for file extent, have %u expect range [0, %u]",
245 			btrfs_file_extent_type(leaf, fi),
246 			BTRFS_NR_FILE_EXTENT_TYPES - 1);
247 		return -EUCLEAN;
248 	}
249 
250 	/*
251 	 * Support for new compression/encryption must introduce incompat flag,
252 	 * and must be caught in open_ctree().
253 	 */
254 	if (unlikely(btrfs_file_extent_compression(leaf, fi) >=
255 		     BTRFS_NR_COMPRESS_TYPES)) {
256 		file_extent_err(leaf, slot,
257 	"invalid compression for file extent, have %u expect range [0, %u]",
258 			btrfs_file_extent_compression(leaf, fi),
259 			BTRFS_NR_COMPRESS_TYPES - 1);
260 		return -EUCLEAN;
261 	}
262 	if (unlikely(btrfs_file_extent_encryption(leaf, fi))) {
263 		file_extent_err(leaf, slot,
264 			"invalid encryption for file extent, have %u expect 0",
265 			btrfs_file_extent_encryption(leaf, fi));
266 		return -EUCLEAN;
267 	}
268 	if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
269 		/* Inline extent must have 0 as key offset */
270 		if (unlikely(key->offset)) {
271 			file_extent_err(leaf, slot,
272 		"invalid file_offset for inline file extent, have %llu expect 0",
273 				key->offset);
274 			return -EUCLEAN;
275 		}
276 
277 		/* Compressed inline extent has no on-disk size, skip it */
278 		if (btrfs_file_extent_compression(leaf, fi) !=
279 		    BTRFS_COMPRESS_NONE)
280 			return 0;
281 
282 		/* Uncompressed inline extent size must match item size */
283 		if (unlikely(item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
284 					  btrfs_file_extent_ram_bytes(leaf, fi))) {
285 			file_extent_err(leaf, slot,
286 	"invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
287 				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
288 				btrfs_file_extent_ram_bytes(leaf, fi));
289 			return -EUCLEAN;
290 		}
291 		return 0;
292 	}
293 
294 	/* Regular or preallocated extent has fixed item size */
295 	if (unlikely(item_size != sizeof(*fi))) {
296 		file_extent_err(leaf, slot,
297 	"invalid item size for reg/prealloc file extent, have %u expect %zu",
298 			item_size, sizeof(*fi));
299 		return -EUCLEAN;
300 	}
301 	if (unlikely(CHECK_FE_ALIGNED(leaf, slot, fi, ram_bytes, sectorsize) ||
302 		     CHECK_FE_ALIGNED(leaf, slot, fi, disk_bytenr, sectorsize) ||
303 		     CHECK_FE_ALIGNED(leaf, slot, fi, disk_num_bytes, sectorsize) ||
304 		     CHECK_FE_ALIGNED(leaf, slot, fi, offset, sectorsize) ||
305 		     CHECK_FE_ALIGNED(leaf, slot, fi, num_bytes, sectorsize)))
306 		return -EUCLEAN;
307 
308 	/* Catch extent end overflow */
309 	if (unlikely(check_add_overflow(btrfs_file_extent_num_bytes(leaf, fi),
310 					key->offset, &extent_end))) {
311 		file_extent_err(leaf, slot,
312 	"extent end overflow, have file offset %llu extent num bytes %llu",
313 				key->offset,
314 				btrfs_file_extent_num_bytes(leaf, fi));
315 		return -EUCLEAN;
316 	}
317 
318 	/*
319 	 * Check that no two consecutive file extent items, in the same leaf,
320 	 * present ranges that overlap each other.
321 	 */
322 	if (slot > 0 &&
323 	    prev_key->objectid == key->objectid &&
324 	    prev_key->type == BTRFS_EXTENT_DATA_KEY) {
325 		struct btrfs_file_extent_item *prev_fi;
326 		u64 prev_end;
327 
328 		prev_fi = btrfs_item_ptr(leaf, slot - 1,
329 					 struct btrfs_file_extent_item);
330 		prev_end = file_extent_end(leaf, prev_key, prev_fi);
331 		if (unlikely(prev_end > key->offset)) {
332 			file_extent_err(leaf, slot - 1,
333 "file extent end range (%llu) goes beyond start offset (%llu) of the next file extent",
334 					prev_end, key->offset);
335 			return -EUCLEAN;
336 		}
337 	}
338 
339 	return 0;
340 }
341 
342 static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
343 			   int slot, struct btrfs_key *prev_key)
344 {
345 	struct btrfs_fs_info *fs_info = leaf->fs_info;
346 	u32 sectorsize = fs_info->sectorsize;
347 	const u32 csumsize = fs_info->csum_size;
348 
349 	if (unlikely(key->objectid != BTRFS_EXTENT_CSUM_OBJECTID)) {
350 		generic_err(leaf, slot,
351 		"invalid key objectid for csum item, have %llu expect %llu",
352 			key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
353 		return -EUCLEAN;
354 	}
355 	if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
356 		generic_err(leaf, slot,
357 	"unaligned key offset for csum item, have %llu should be aligned to %u",
358 			key->offset, sectorsize);
359 		return -EUCLEAN;
360 	}
361 	if (unlikely(!IS_ALIGNED(btrfs_item_size(leaf, slot), csumsize))) {
362 		generic_err(leaf, slot,
363 	"unaligned item size for csum item, have %u should be aligned to %u",
364 			btrfs_item_size(leaf, slot), csumsize);
365 		return -EUCLEAN;
366 	}
367 	if (slot > 0 && prev_key->type == BTRFS_EXTENT_CSUM_KEY) {
368 		u64 prev_csum_end;
369 		u32 prev_item_size;
370 
371 		prev_item_size = btrfs_item_size(leaf, slot - 1);
372 		prev_csum_end = (prev_item_size / csumsize) * sectorsize;
373 		prev_csum_end += prev_key->offset;
374 		if (unlikely(prev_csum_end > key->offset)) {
375 			generic_err(leaf, slot - 1,
376 "csum end range (%llu) goes beyond the start range (%llu) of the next csum item",
377 				    prev_csum_end, key->offset);
378 			return -EUCLEAN;
379 		}
380 	}
381 	return 0;
382 }
383 
384 /* Inode item error output has the same format as dir_item_err() */
385 #define inode_item_err(eb, slot, fmt, ...)			\
386 	dir_item_err(eb, slot, fmt, __VA_ARGS__)
387 
388 static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key,
389 			   int slot)
390 {
391 	struct btrfs_key item_key;
392 	bool is_inode_item;
393 
394 	btrfs_item_key_to_cpu(leaf, &item_key, slot);
395 	is_inode_item = (item_key.type == BTRFS_INODE_ITEM_KEY);
396 
397 	/* For XATTR_ITEM, location key should be all 0 */
398 	if (item_key.type == BTRFS_XATTR_ITEM_KEY) {
399 		if (unlikely(key->objectid != 0 || key->type != 0 ||
400 			     key->offset != 0))
401 			return -EUCLEAN;
402 		return 0;
403 	}
404 
405 	if (unlikely((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
406 		      key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
407 		     key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
408 		     key->objectid != BTRFS_FREE_INO_OBJECTID)) {
409 		if (is_inode_item) {
410 			generic_err(leaf, slot,
411 	"invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
412 				key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
413 				BTRFS_FIRST_FREE_OBJECTID,
414 				BTRFS_LAST_FREE_OBJECTID,
415 				BTRFS_FREE_INO_OBJECTID);
416 		} else {
417 			dir_item_err(leaf, slot,
418 "invalid location key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
419 				key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
420 				BTRFS_FIRST_FREE_OBJECTID,
421 				BTRFS_LAST_FREE_OBJECTID,
422 				BTRFS_FREE_INO_OBJECTID);
423 		}
424 		return -EUCLEAN;
425 	}
426 	if (unlikely(key->offset != 0)) {
427 		if (is_inode_item)
428 			inode_item_err(leaf, slot,
429 				       "invalid key offset: has %llu expect 0",
430 				       key->offset);
431 		else
432 			dir_item_err(leaf, slot,
433 				"invalid location key offset:has %llu expect 0",
434 				key->offset);
435 		return -EUCLEAN;
436 	}
437 	return 0;
438 }
439 
440 static int check_root_key(struct extent_buffer *leaf, struct btrfs_key *key,
441 			  int slot)
442 {
443 	struct btrfs_key item_key;
444 	bool is_root_item;
445 
446 	btrfs_item_key_to_cpu(leaf, &item_key, slot);
447 	is_root_item = (item_key.type == BTRFS_ROOT_ITEM_KEY);
448 
449 	/* No such tree id */
450 	if (unlikely(key->objectid == 0)) {
451 		if (is_root_item)
452 			generic_err(leaf, slot, "invalid root id 0");
453 		else
454 			dir_item_err(leaf, slot,
455 				     "invalid location key root id 0");
456 		return -EUCLEAN;
457 	}
458 
459 	/* DIR_ITEM/INDEX/INODE_REF is not allowed to point to non-fs trees */
460 	if (unlikely(!is_fstree(key->objectid) && !is_root_item)) {
461 		dir_item_err(leaf, slot,
462 		"invalid location key objectid, have %llu expect [%llu, %llu]",
463 				key->objectid, BTRFS_FIRST_FREE_OBJECTID,
464 				BTRFS_LAST_FREE_OBJECTID);
465 		return -EUCLEAN;
466 	}
467 
468 	/*
469 	 * ROOT_ITEM with non-zero offset means this is a snapshot, created at
470 	 * @offset transid.
471 	 * Furthermore, for location key in DIR_ITEM, its offset is always -1.
472 	 *
473 	 * So here we only check offset for reloc tree whose key->offset must
474 	 * be a valid tree.
475 	 */
476 	if (unlikely(key->objectid == BTRFS_TREE_RELOC_OBJECTID &&
477 		     key->offset == 0)) {
478 		generic_err(leaf, slot, "invalid root id 0 for reloc tree");
479 		return -EUCLEAN;
480 	}
481 	return 0;
482 }
483 
484 static int check_dir_item(struct extent_buffer *leaf,
485 			  struct btrfs_key *key, struct btrfs_key *prev_key,
486 			  int slot)
487 {
488 	struct btrfs_fs_info *fs_info = leaf->fs_info;
489 	struct btrfs_dir_item *di;
490 	u32 item_size = btrfs_item_size(leaf, slot);
491 	u32 cur = 0;
492 
493 	if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
494 		return -EUCLEAN;
495 
496 	di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
497 	while (cur < item_size) {
498 		struct btrfs_key location_key;
499 		u32 name_len;
500 		u32 data_len;
501 		u32 max_name_len;
502 		u32 total_size;
503 		u32 name_hash;
504 		u8 dir_type;
505 		int ret;
506 
507 		/* header itself should not cross item boundary */
508 		if (unlikely(cur + sizeof(*di) > item_size)) {
509 			dir_item_err(leaf, slot,
510 		"dir item header crosses item boundary, have %zu boundary %u",
511 				cur + sizeof(*di), item_size);
512 			return -EUCLEAN;
513 		}
514 
515 		/* Location key check */
516 		btrfs_dir_item_key_to_cpu(leaf, di, &location_key);
517 		if (location_key.type == BTRFS_ROOT_ITEM_KEY) {
518 			ret = check_root_key(leaf, &location_key, slot);
519 			if (unlikely(ret < 0))
520 				return ret;
521 		} else if (location_key.type == BTRFS_INODE_ITEM_KEY ||
522 			   location_key.type == 0) {
523 			ret = check_inode_key(leaf, &location_key, slot);
524 			if (unlikely(ret < 0))
525 				return ret;
526 		} else {
527 			dir_item_err(leaf, slot,
528 			"invalid location key type, have %u, expect %u or %u",
529 				     location_key.type, BTRFS_ROOT_ITEM_KEY,
530 				     BTRFS_INODE_ITEM_KEY);
531 			return -EUCLEAN;
532 		}
533 
534 		/* dir type check */
535 		dir_type = btrfs_dir_ftype(leaf, di);
536 		if (unlikely(dir_type >= BTRFS_FT_MAX)) {
537 			dir_item_err(leaf, slot,
538 			"invalid dir item type, have %u expect [0, %u)",
539 				dir_type, BTRFS_FT_MAX);
540 			return -EUCLEAN;
541 		}
542 
543 		if (unlikely(key->type == BTRFS_XATTR_ITEM_KEY &&
544 			     dir_type != BTRFS_FT_XATTR)) {
545 			dir_item_err(leaf, slot,
546 		"invalid dir item type for XATTR key, have %u expect %u",
547 				dir_type, BTRFS_FT_XATTR);
548 			return -EUCLEAN;
549 		}
550 		if (unlikely(dir_type == BTRFS_FT_XATTR &&
551 			     key->type != BTRFS_XATTR_ITEM_KEY)) {
552 			dir_item_err(leaf, slot,
553 			"xattr dir type found for non-XATTR key");
554 			return -EUCLEAN;
555 		}
556 		if (dir_type == BTRFS_FT_XATTR)
557 			max_name_len = XATTR_NAME_MAX;
558 		else
559 			max_name_len = BTRFS_NAME_LEN;
560 
561 		/* Name/data length check */
562 		name_len = btrfs_dir_name_len(leaf, di);
563 		data_len = btrfs_dir_data_len(leaf, di);
564 		if (unlikely(name_len > max_name_len)) {
565 			dir_item_err(leaf, slot,
566 			"dir item name len too long, have %u max %u",
567 				name_len, max_name_len);
568 			return -EUCLEAN;
569 		}
570 		if (unlikely(name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info))) {
571 			dir_item_err(leaf, slot,
572 			"dir item name and data len too long, have %u max %u",
573 				name_len + data_len,
574 				BTRFS_MAX_XATTR_SIZE(fs_info));
575 			return -EUCLEAN;
576 		}
577 
578 		if (unlikely(data_len && dir_type != BTRFS_FT_XATTR)) {
579 			dir_item_err(leaf, slot,
580 			"dir item with invalid data len, have %u expect 0",
581 				data_len);
582 			return -EUCLEAN;
583 		}
584 
585 		total_size = sizeof(*di) + name_len + data_len;
586 
587 		/* header and name/data should not cross item boundary */
588 		if (unlikely(cur + total_size > item_size)) {
589 			dir_item_err(leaf, slot,
590 		"dir item data crosses item boundary, have %u boundary %u",
591 				cur + total_size, item_size);
592 			return -EUCLEAN;
593 		}
594 
595 		/*
596 		 * Special check for XATTR/DIR_ITEM, as key->offset is name
597 		 * hash, should match its name
598 		 */
599 		if (key->type == BTRFS_DIR_ITEM_KEY ||
600 		    key->type == BTRFS_XATTR_ITEM_KEY) {
601 			char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)];
602 
603 			read_extent_buffer(leaf, namebuf,
604 					(unsigned long)(di + 1), name_len);
605 			name_hash = btrfs_name_hash(namebuf, name_len);
606 			if (unlikely(key->offset != name_hash)) {
607 				dir_item_err(leaf, slot,
608 		"name hash mismatch with key, have 0x%016x expect 0x%016llx",
609 					name_hash, key->offset);
610 				return -EUCLEAN;
611 			}
612 		}
613 		cur += total_size;
614 		di = (struct btrfs_dir_item *)((void *)di + total_size);
615 	}
616 	return 0;
617 }
618 
619 __printf(3, 4)
620 __cold
621 static void block_group_err(const struct extent_buffer *eb, int slot,
622 			    const char *fmt, ...)
623 {
624 	const struct btrfs_fs_info *fs_info = eb->fs_info;
625 	struct btrfs_key key;
626 	struct va_format vaf;
627 	va_list args;
628 
629 	btrfs_item_key_to_cpu(eb, &key, slot);
630 	va_start(args, fmt);
631 
632 	vaf.fmt = fmt;
633 	vaf.va = &args;
634 
635 	btrfs_crit(fs_info,
636 	"corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV",
637 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
638 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
639 		key.objectid, key.offset, &vaf);
640 	va_end(args);
641 }
642 
643 static int check_block_group_item(struct extent_buffer *leaf,
644 				  struct btrfs_key *key, int slot)
645 {
646 	struct btrfs_fs_info *fs_info = leaf->fs_info;
647 	struct btrfs_block_group_item bgi;
648 	u32 item_size = btrfs_item_size(leaf, slot);
649 	u64 chunk_objectid;
650 	u64 flags;
651 	u64 type;
652 
653 	/*
654 	 * Here we don't really care about alignment since extent allocator can
655 	 * handle it.  We care more about the size.
656 	 */
657 	if (unlikely(key->offset == 0)) {
658 		block_group_err(leaf, slot,
659 				"invalid block group size 0");
660 		return -EUCLEAN;
661 	}
662 
663 	if (unlikely(item_size != sizeof(bgi))) {
664 		block_group_err(leaf, slot,
665 			"invalid item size, have %u expect %zu",
666 				item_size, sizeof(bgi));
667 		return -EUCLEAN;
668 	}
669 
670 	read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
671 			   sizeof(bgi));
672 	chunk_objectid = btrfs_stack_block_group_chunk_objectid(&bgi);
673 	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
674 		/*
675 		 * We don't init the nr_global_roots until we load the global
676 		 * roots, so this could be 0 at mount time.  If it's 0 we'll
677 		 * just assume we're fine, and later we'll check against our
678 		 * actual value.
679 		 */
680 		if (unlikely(fs_info->nr_global_roots &&
681 			     chunk_objectid >= fs_info->nr_global_roots)) {
682 			block_group_err(leaf, slot,
683 	"invalid block group global root id, have %llu, needs to be <= %llu",
684 					chunk_objectid,
685 					fs_info->nr_global_roots);
686 			return -EUCLEAN;
687 		}
688 	} else if (unlikely(chunk_objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID)) {
689 		block_group_err(leaf, slot,
690 		"invalid block group chunk objectid, have %llu expect %llu",
691 				btrfs_stack_block_group_chunk_objectid(&bgi),
692 				BTRFS_FIRST_CHUNK_TREE_OBJECTID);
693 		return -EUCLEAN;
694 	}
695 
696 	if (unlikely(btrfs_stack_block_group_used(&bgi) > key->offset)) {
697 		block_group_err(leaf, slot,
698 			"invalid block group used, have %llu expect [0, %llu)",
699 				btrfs_stack_block_group_used(&bgi), key->offset);
700 		return -EUCLEAN;
701 	}
702 
703 	flags = btrfs_stack_block_group_flags(&bgi);
704 	if (unlikely(hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1)) {
705 		block_group_err(leaf, slot,
706 "invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set",
707 			flags & BTRFS_BLOCK_GROUP_PROFILE_MASK,
708 			hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK));
709 		return -EUCLEAN;
710 	}
711 
712 	type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
713 	if (unlikely(type != BTRFS_BLOCK_GROUP_DATA &&
714 		     type != BTRFS_BLOCK_GROUP_METADATA &&
715 		     type != BTRFS_BLOCK_GROUP_SYSTEM &&
716 		     type != (BTRFS_BLOCK_GROUP_METADATA |
717 			      BTRFS_BLOCK_GROUP_DATA))) {
718 		block_group_err(leaf, slot,
719 "invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx or 0x%llx",
720 			type, hweight64(type),
721 			BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
722 			BTRFS_BLOCK_GROUP_SYSTEM,
723 			BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA);
724 		return -EUCLEAN;
725 	}
726 	return 0;
727 }
728 
729 __printf(4, 5)
730 __cold
731 static void chunk_err(const struct extent_buffer *leaf,
732 		      const struct btrfs_chunk *chunk, u64 logical,
733 		      const char *fmt, ...)
734 {
735 	const struct btrfs_fs_info *fs_info = leaf->fs_info;
736 	bool is_sb;
737 	struct va_format vaf;
738 	va_list args;
739 	int i;
740 	int slot = -1;
741 
742 	/* Only superblock eb is able to have such small offset */
743 	is_sb = (leaf->start == BTRFS_SUPER_INFO_OFFSET);
744 
745 	if (!is_sb) {
746 		/*
747 		 * Get the slot number by iterating through all slots, this
748 		 * would provide better readability.
749 		 */
750 		for (i = 0; i < btrfs_header_nritems(leaf); i++) {
751 			if (btrfs_item_ptr_offset(leaf, i) ==
752 					(unsigned long)chunk) {
753 				slot = i;
754 				break;
755 			}
756 		}
757 	}
758 	va_start(args, fmt);
759 	vaf.fmt = fmt;
760 	vaf.va = &args;
761 
762 	if (is_sb)
763 		btrfs_crit(fs_info,
764 		"corrupt superblock syschunk array: chunk_start=%llu, %pV",
765 			   logical, &vaf);
766 	else
767 		btrfs_crit(fs_info,
768 	"corrupt leaf: root=%llu block=%llu slot=%d chunk_start=%llu, %pV",
769 			   BTRFS_CHUNK_TREE_OBJECTID, leaf->start, slot,
770 			   logical, &vaf);
771 	va_end(args);
772 }
773 
774 /*
775  * The common chunk check which could also work on super block sys chunk array.
776  *
777  * Return -EUCLEAN if anything is corrupted.
778  * Return 0 if everything is OK.
779  */
780 int btrfs_check_chunk_valid(struct extent_buffer *leaf,
781 			    struct btrfs_chunk *chunk, u64 logical)
782 {
783 	struct btrfs_fs_info *fs_info = leaf->fs_info;
784 	u64 length;
785 	u64 chunk_end;
786 	u64 stripe_len;
787 	u16 num_stripes;
788 	u16 sub_stripes;
789 	u64 type;
790 	u64 features;
791 	bool mixed = false;
792 	int raid_index;
793 	int nparity;
794 	int ncopies;
795 
796 	length = btrfs_chunk_length(leaf, chunk);
797 	stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
798 	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
799 	sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
800 	type = btrfs_chunk_type(leaf, chunk);
801 	raid_index = btrfs_bg_flags_to_raid_index(type);
802 	ncopies = btrfs_raid_array[raid_index].ncopies;
803 	nparity = btrfs_raid_array[raid_index].nparity;
804 
805 	if (unlikely(!num_stripes)) {
806 		chunk_err(leaf, chunk, logical,
807 			  "invalid chunk num_stripes, have %u", num_stripes);
808 		return -EUCLEAN;
809 	}
810 	if (unlikely(num_stripes < ncopies)) {
811 		chunk_err(leaf, chunk, logical,
812 			  "invalid chunk num_stripes < ncopies, have %u < %d",
813 			  num_stripes, ncopies);
814 		return -EUCLEAN;
815 	}
816 	if (unlikely(nparity && num_stripes == nparity)) {
817 		chunk_err(leaf, chunk, logical,
818 			  "invalid chunk num_stripes == nparity, have %u == %d",
819 			  num_stripes, nparity);
820 		return -EUCLEAN;
821 	}
822 	if (unlikely(!IS_ALIGNED(logical, fs_info->sectorsize))) {
823 		chunk_err(leaf, chunk, logical,
824 		"invalid chunk logical, have %llu should aligned to %u",
825 			  logical, fs_info->sectorsize);
826 		return -EUCLEAN;
827 	}
828 	if (unlikely(btrfs_chunk_sector_size(leaf, chunk) != fs_info->sectorsize)) {
829 		chunk_err(leaf, chunk, logical,
830 			  "invalid chunk sectorsize, have %u expect %u",
831 			  btrfs_chunk_sector_size(leaf, chunk),
832 			  fs_info->sectorsize);
833 		return -EUCLEAN;
834 	}
835 	if (unlikely(!length || !IS_ALIGNED(length, fs_info->sectorsize))) {
836 		chunk_err(leaf, chunk, logical,
837 			  "invalid chunk length, have %llu", length);
838 		return -EUCLEAN;
839 	}
840 	if (unlikely(check_add_overflow(logical, length, &chunk_end))) {
841 		chunk_err(leaf, chunk, logical,
842 "invalid chunk logical start and length, have logical start %llu length %llu",
843 			  logical, length);
844 		return -EUCLEAN;
845 	}
846 	if (unlikely(!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN)) {
847 		chunk_err(leaf, chunk, logical,
848 			  "invalid chunk stripe length: %llu",
849 			  stripe_len);
850 		return -EUCLEAN;
851 	}
852 	/*
853 	 * We artificially limit the chunk size, so that the number of stripes
854 	 * inside a chunk can be fit into a U32.  The current limit (256G) is
855 	 * way too large for real world usage anyway, and it's also much larger
856 	 * than our existing limit (10G).
857 	 *
858 	 * Thus it should be a good way to catch obvious bitflips.
859 	 */
860 	if (unlikely(length >= btrfs_stripe_nr_to_offset(U32_MAX))) {
861 		chunk_err(leaf, chunk, logical,
862 			  "chunk length too large: have %llu limit %llu",
863 			  length, btrfs_stripe_nr_to_offset(U32_MAX));
864 		return -EUCLEAN;
865 	}
866 	if (unlikely(type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
867 			      BTRFS_BLOCK_GROUP_PROFILE_MASK))) {
868 		chunk_err(leaf, chunk, logical,
869 			  "unrecognized chunk type: 0x%llx",
870 			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
871 			    BTRFS_BLOCK_GROUP_PROFILE_MASK) &
872 			  btrfs_chunk_type(leaf, chunk));
873 		return -EUCLEAN;
874 	}
875 
876 	if (unlikely(!has_single_bit_set(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
877 		     (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0)) {
878 		chunk_err(leaf, chunk, logical,
879 		"invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
880 			  type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
881 		return -EUCLEAN;
882 	}
883 	if (unlikely((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0)) {
884 		chunk_err(leaf, chunk, logical,
885 	"missing chunk type flag, have 0x%llx one bit must be set in 0x%llx",
886 			  type, BTRFS_BLOCK_GROUP_TYPE_MASK);
887 		return -EUCLEAN;
888 	}
889 
890 	if (unlikely((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
891 		     (type & (BTRFS_BLOCK_GROUP_METADATA |
892 			      BTRFS_BLOCK_GROUP_DATA)))) {
893 		chunk_err(leaf, chunk, logical,
894 			  "system chunk with data or metadata type: 0x%llx",
895 			  type);
896 		return -EUCLEAN;
897 	}
898 
899 	features = btrfs_super_incompat_flags(fs_info->super_copy);
900 	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
901 		mixed = true;
902 
903 	if (!mixed) {
904 		if (unlikely((type & BTRFS_BLOCK_GROUP_METADATA) &&
905 			     (type & BTRFS_BLOCK_GROUP_DATA))) {
906 			chunk_err(leaf, chunk, logical,
907 			"mixed chunk type in non-mixed mode: 0x%llx", type);
908 			return -EUCLEAN;
909 		}
910 	}
911 
912 	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 &&
913 		      sub_stripes != btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes) ||
914 		     (type & BTRFS_BLOCK_GROUP_RAID1 &&
915 		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1].devs_min) ||
916 		     (type & BTRFS_BLOCK_GROUP_RAID1C3 &&
917 		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C3].devs_min) ||
918 		     (type & BTRFS_BLOCK_GROUP_RAID1C4 &&
919 		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C4].devs_min) ||
920 		     (type & BTRFS_BLOCK_GROUP_RAID5 &&
921 		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID5].devs_min) ||
922 		     (type & BTRFS_BLOCK_GROUP_RAID6 &&
923 		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID6].devs_min) ||
924 		     (type & BTRFS_BLOCK_GROUP_DUP &&
925 		      num_stripes != btrfs_raid_array[BTRFS_RAID_DUP].dev_stripes) ||
926 		     ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
927 		      num_stripes != btrfs_raid_array[BTRFS_RAID_SINGLE].dev_stripes))) {
928 		chunk_err(leaf, chunk, logical,
929 			"invalid num_stripes:sub_stripes %u:%u for profile %llu",
930 			num_stripes, sub_stripes,
931 			type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
932 		return -EUCLEAN;
933 	}
934 
935 	return 0;
936 }
937 
938 /*
939  * Enhanced version of chunk item checker.
940  *
941  * The common btrfs_check_chunk_valid() doesn't check item size since it needs
942  * to work on super block sys_chunk_array which doesn't have full item ptr.
943  */
944 static int check_leaf_chunk_item(struct extent_buffer *leaf,
945 				 struct btrfs_chunk *chunk,
946 				 struct btrfs_key *key, int slot)
947 {
948 	int num_stripes;
949 
950 	if (unlikely(btrfs_item_size(leaf, slot) < sizeof(struct btrfs_chunk))) {
951 		chunk_err(leaf, chunk, key->offset,
952 			"invalid chunk item size: have %u expect [%zu, %u)",
953 			btrfs_item_size(leaf, slot),
954 			sizeof(struct btrfs_chunk),
955 			BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
956 		return -EUCLEAN;
957 	}
958 
959 	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
960 	/* Let btrfs_check_chunk_valid() handle this error type */
961 	if (num_stripes == 0)
962 		goto out;
963 
964 	if (unlikely(btrfs_chunk_item_size(num_stripes) !=
965 		     btrfs_item_size(leaf, slot))) {
966 		chunk_err(leaf, chunk, key->offset,
967 			"invalid chunk item size: have %u expect %lu",
968 			btrfs_item_size(leaf, slot),
969 			btrfs_chunk_item_size(num_stripes));
970 		return -EUCLEAN;
971 	}
972 out:
973 	return btrfs_check_chunk_valid(leaf, chunk, key->offset);
974 }
975 
976 __printf(3, 4)
977 __cold
978 static void dev_item_err(const struct extent_buffer *eb, int slot,
979 			 const char *fmt, ...)
980 {
981 	struct btrfs_key key;
982 	struct va_format vaf;
983 	va_list args;
984 
985 	btrfs_item_key_to_cpu(eb, &key, slot);
986 	va_start(args, fmt);
987 
988 	vaf.fmt = fmt;
989 	vaf.va = &args;
990 
991 	btrfs_crit(eb->fs_info,
992 	"corrupt %s: root=%llu block=%llu slot=%d devid=%llu %pV",
993 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
994 		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
995 		key.objectid, &vaf);
996 	va_end(args);
997 }
998 
999 static int check_dev_item(struct extent_buffer *leaf,
1000 			  struct btrfs_key *key, int slot)
1001 {
1002 	struct btrfs_dev_item *ditem;
1003 	const u32 item_size = btrfs_item_size(leaf, slot);
1004 
1005 	if (unlikely(key->objectid != BTRFS_DEV_ITEMS_OBJECTID)) {
1006 		dev_item_err(leaf, slot,
1007 			     "invalid objectid: has=%llu expect=%llu",
1008 			     key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
1009 		return -EUCLEAN;
1010 	}
1011 
1012 	if (unlikely(item_size != sizeof(*ditem))) {
1013 		dev_item_err(leaf, slot, "invalid item size: has %u expect %zu",
1014 			     item_size, sizeof(*ditem));
1015 		return -EUCLEAN;
1016 	}
1017 
1018 	ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
1019 	if (unlikely(btrfs_device_id(leaf, ditem) != key->offset)) {
1020 		dev_item_err(leaf, slot,
1021 			     "devid mismatch: key has=%llu item has=%llu",
1022 			     key->offset, btrfs_device_id(leaf, ditem));
1023 		return -EUCLEAN;
1024 	}
1025 
1026 	/*
1027 	 * For device total_bytes, we don't have reliable way to check it, as
1028 	 * it can be 0 for device removal. Device size check can only be done
1029 	 * by dev extents check.
1030 	 */
1031 	if (unlikely(btrfs_device_bytes_used(leaf, ditem) >
1032 		     btrfs_device_total_bytes(leaf, ditem))) {
1033 		dev_item_err(leaf, slot,
1034 			     "invalid bytes used: have %llu expect [0, %llu]",
1035 			     btrfs_device_bytes_used(leaf, ditem),
1036 			     btrfs_device_total_bytes(leaf, ditem));
1037 		return -EUCLEAN;
1038 	}
1039 	/*
1040 	 * Remaining members like io_align/type/gen/dev_group aren't really
1041 	 * utilized.  Skip them to make later usage of them easier.
1042 	 */
1043 	return 0;
1044 }
1045 
1046 static int check_inode_item(struct extent_buffer *leaf,
1047 			    struct btrfs_key *key, int slot)
1048 {
1049 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1050 	struct btrfs_inode_item *iitem;
1051 	u64 super_gen = btrfs_super_generation(fs_info->super_copy);
1052 	u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
1053 	const u32 item_size = btrfs_item_size(leaf, slot);
1054 	u32 mode;
1055 	int ret;
1056 	u32 flags;
1057 	u32 ro_flags;
1058 
1059 	ret = check_inode_key(leaf, key, slot);
1060 	if (unlikely(ret < 0))
1061 		return ret;
1062 
1063 	if (unlikely(item_size != sizeof(*iitem))) {
1064 		generic_err(leaf, slot, "invalid item size: has %u expect %zu",
1065 			    item_size, sizeof(*iitem));
1066 		return -EUCLEAN;
1067 	}
1068 
1069 	iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);
1070 
1071 	/* Here we use super block generation + 1 to handle log tree */
1072 	if (unlikely(btrfs_inode_generation(leaf, iitem) > super_gen + 1)) {
1073 		inode_item_err(leaf, slot,
1074 			"invalid inode generation: has %llu expect (0, %llu]",
1075 			       btrfs_inode_generation(leaf, iitem),
1076 			       super_gen + 1);
1077 		return -EUCLEAN;
1078 	}
1079 	/* Note for ROOT_TREE_DIR_ITEM, mkfs could set its transid 0 */
1080 	if (unlikely(btrfs_inode_transid(leaf, iitem) > super_gen + 1)) {
1081 		inode_item_err(leaf, slot,
1082 			"invalid inode transid: has %llu expect [0, %llu]",
1083 			       btrfs_inode_transid(leaf, iitem), super_gen + 1);
1084 		return -EUCLEAN;
1085 	}
1086 
1087 	/*
1088 	 * For size and nbytes it's better not to be too strict, as for dir
1089 	 * item its size/nbytes can easily get wrong, but doesn't affect
1090 	 * anything in the fs. So here we skip the check.
1091 	 */
1092 	mode = btrfs_inode_mode(leaf, iitem);
1093 	if (unlikely(mode & ~valid_mask)) {
1094 		inode_item_err(leaf, slot,
1095 			       "unknown mode bit detected: 0x%x",
1096 			       mode & ~valid_mask);
1097 		return -EUCLEAN;
1098 	}
1099 
1100 	/*
1101 	 * S_IFMT is not bit mapped so we can't completely rely on
1102 	 * is_power_of_2/has_single_bit_set, but it can save us from checking
1103 	 * FIFO/CHR/DIR/REG.  Only needs to check BLK, LNK and SOCKS
1104 	 */
1105 	if (!has_single_bit_set(mode & S_IFMT)) {
1106 		if (unlikely(!S_ISLNK(mode) && !S_ISBLK(mode) && !S_ISSOCK(mode))) {
1107 			inode_item_err(leaf, slot,
1108 			"invalid mode: has 0%o expect valid S_IF* bit(s)",
1109 				       mode & S_IFMT);
1110 			return -EUCLEAN;
1111 		}
1112 	}
1113 	if (unlikely(S_ISDIR(mode) && btrfs_inode_nlink(leaf, iitem) > 1)) {
1114 		inode_item_err(leaf, slot,
1115 		       "invalid nlink: has %u expect no more than 1 for dir",
1116 			btrfs_inode_nlink(leaf, iitem));
1117 		return -EUCLEAN;
1118 	}
1119 	btrfs_inode_split_flags(btrfs_inode_flags(leaf, iitem), &flags, &ro_flags);
1120 	if (unlikely(flags & ~BTRFS_INODE_FLAG_MASK)) {
1121 		inode_item_err(leaf, slot,
1122 			       "unknown incompat flags detected: 0x%x", flags);
1123 		return -EUCLEAN;
1124 	}
1125 	if (unlikely(!sb_rdonly(fs_info->sb) &&
1126 		     (ro_flags & ~BTRFS_INODE_RO_FLAG_MASK))) {
1127 		inode_item_err(leaf, slot,
1128 			"unknown ro-compat flags detected on writeable mount: 0x%x",
1129 			ro_flags);
1130 		return -EUCLEAN;
1131 	}
1132 	return 0;
1133 }
1134 
1135 static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
1136 			   int slot)
1137 {
1138 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1139 	struct btrfs_root_item ri = { 0 };
1140 	const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY |
1141 				     BTRFS_ROOT_SUBVOL_DEAD;
1142 	int ret;
1143 
1144 	ret = check_root_key(leaf, key, slot);
1145 	if (unlikely(ret < 0))
1146 		return ret;
1147 
1148 	if (unlikely(btrfs_item_size(leaf, slot) != sizeof(ri) &&
1149 		     btrfs_item_size(leaf, slot) !=
1150 		     btrfs_legacy_root_item_size())) {
1151 		generic_err(leaf, slot,
1152 			    "invalid root item size, have %u expect %zu or %u",
1153 			    btrfs_item_size(leaf, slot), sizeof(ri),
1154 			    btrfs_legacy_root_item_size());
1155 		return -EUCLEAN;
1156 	}
1157 
1158 	/*
1159 	 * For legacy root item, the members starting at generation_v2 will be
1160 	 * all filled with 0.
1161 	 * And since we allow geneartion_v2 as 0, it will still pass the check.
1162 	 */
1163 	read_extent_buffer(leaf, &ri, btrfs_item_ptr_offset(leaf, slot),
1164 			   btrfs_item_size(leaf, slot));
1165 
1166 	/* Generation related */
1167 	if (unlikely(btrfs_root_generation(&ri) >
1168 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1169 		generic_err(leaf, slot,
1170 			"invalid root generation, have %llu expect (0, %llu]",
1171 			    btrfs_root_generation(&ri),
1172 			    btrfs_super_generation(fs_info->super_copy) + 1);
1173 		return -EUCLEAN;
1174 	}
1175 	if (unlikely(btrfs_root_generation_v2(&ri) >
1176 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1177 		generic_err(leaf, slot,
1178 		"invalid root v2 generation, have %llu expect (0, %llu]",
1179 			    btrfs_root_generation_v2(&ri),
1180 			    btrfs_super_generation(fs_info->super_copy) + 1);
1181 		return -EUCLEAN;
1182 	}
1183 	if (unlikely(btrfs_root_last_snapshot(&ri) >
1184 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1185 		generic_err(leaf, slot,
1186 		"invalid root last_snapshot, have %llu expect (0, %llu]",
1187 			    btrfs_root_last_snapshot(&ri),
1188 			    btrfs_super_generation(fs_info->super_copy) + 1);
1189 		return -EUCLEAN;
1190 	}
1191 
1192 	/* Alignment and level check */
1193 	if (unlikely(!IS_ALIGNED(btrfs_root_bytenr(&ri), fs_info->sectorsize))) {
1194 		generic_err(leaf, slot,
1195 		"invalid root bytenr, have %llu expect to be aligned to %u",
1196 			    btrfs_root_bytenr(&ri), fs_info->sectorsize);
1197 		return -EUCLEAN;
1198 	}
1199 	if (unlikely(btrfs_root_level(&ri) >= BTRFS_MAX_LEVEL)) {
1200 		generic_err(leaf, slot,
1201 			    "invalid root level, have %u expect [0, %u]",
1202 			    btrfs_root_level(&ri), BTRFS_MAX_LEVEL - 1);
1203 		return -EUCLEAN;
1204 	}
1205 	if (unlikely(btrfs_root_drop_level(&ri) >= BTRFS_MAX_LEVEL)) {
1206 		generic_err(leaf, slot,
1207 			    "invalid root level, have %u expect [0, %u]",
1208 			    btrfs_root_drop_level(&ri), BTRFS_MAX_LEVEL - 1);
1209 		return -EUCLEAN;
1210 	}
1211 
1212 	/* Flags check */
1213 	if (unlikely(btrfs_root_flags(&ri) & ~valid_root_flags)) {
1214 		generic_err(leaf, slot,
1215 			    "invalid root flags, have 0x%llx expect mask 0x%llx",
1216 			    btrfs_root_flags(&ri), valid_root_flags);
1217 		return -EUCLEAN;
1218 	}
1219 	return 0;
1220 }
1221 
1222 __printf(3,4)
1223 __cold
1224 static void extent_err(const struct extent_buffer *eb, int slot,
1225 		       const char *fmt, ...)
1226 {
1227 	struct btrfs_key key;
1228 	struct va_format vaf;
1229 	va_list args;
1230 	u64 bytenr;
1231 	u64 len;
1232 
1233 	btrfs_item_key_to_cpu(eb, &key, slot);
1234 	bytenr = key.objectid;
1235 	if (key.type == BTRFS_METADATA_ITEM_KEY ||
1236 	    key.type == BTRFS_TREE_BLOCK_REF_KEY ||
1237 	    key.type == BTRFS_SHARED_BLOCK_REF_KEY)
1238 		len = eb->fs_info->nodesize;
1239 	else
1240 		len = key.offset;
1241 	va_start(args, fmt);
1242 
1243 	vaf.fmt = fmt;
1244 	vaf.va = &args;
1245 
1246 	btrfs_crit(eb->fs_info,
1247 	"corrupt %s: block=%llu slot=%d extent bytenr=%llu len=%llu %pV",
1248 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
1249 		eb->start, slot, bytenr, len, &vaf);
1250 	va_end(args);
1251 }
1252 
1253 static int check_extent_item(struct extent_buffer *leaf,
1254 			     struct btrfs_key *key, int slot,
1255 			     struct btrfs_key *prev_key)
1256 {
1257 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1258 	struct btrfs_extent_item *ei;
1259 	bool is_tree_block = false;
1260 	unsigned long ptr;	/* Current pointer inside inline refs */
1261 	unsigned long end;	/* Extent item end */
1262 	const u32 item_size = btrfs_item_size(leaf, slot);
1263 	u64 flags;
1264 	u64 generation;
1265 	u64 total_refs;		/* Total refs in btrfs_extent_item */
1266 	u64 inline_refs = 0;	/* found total inline refs */
1267 
1268 	if (unlikely(key->type == BTRFS_METADATA_ITEM_KEY &&
1269 		     !btrfs_fs_incompat(fs_info, SKINNY_METADATA))) {
1270 		generic_err(leaf, slot,
1271 "invalid key type, METADATA_ITEM type invalid when SKINNY_METADATA feature disabled");
1272 		return -EUCLEAN;
1273 	}
1274 	/* key->objectid is the bytenr for both key types */
1275 	if (unlikely(!IS_ALIGNED(key->objectid, fs_info->sectorsize))) {
1276 		generic_err(leaf, slot,
1277 		"invalid key objectid, have %llu expect to be aligned to %u",
1278 			   key->objectid, fs_info->sectorsize);
1279 		return -EUCLEAN;
1280 	}
1281 
1282 	/* key->offset is tree level for METADATA_ITEM_KEY */
1283 	if (unlikely(key->type == BTRFS_METADATA_ITEM_KEY &&
1284 		     key->offset >= BTRFS_MAX_LEVEL)) {
1285 		extent_err(leaf, slot,
1286 			   "invalid tree level, have %llu expect [0, %u]",
1287 			   key->offset, BTRFS_MAX_LEVEL - 1);
1288 		return -EUCLEAN;
1289 	}
1290 
1291 	/*
1292 	 * EXTENT/METADATA_ITEM consists of:
1293 	 * 1) One btrfs_extent_item
1294 	 *    Records the total refs, type and generation of the extent.
1295 	 *
1296 	 * 2) One btrfs_tree_block_info (for EXTENT_ITEM and tree backref only)
1297 	 *    Records the first key and level of the tree block.
1298 	 *
1299 	 * 2) Zero or more btrfs_extent_inline_ref(s)
1300 	 *    Each inline ref has one btrfs_extent_inline_ref shows:
1301 	 *    2.1) The ref type, one of the 4
1302 	 *         TREE_BLOCK_REF	Tree block only
1303 	 *         SHARED_BLOCK_REF	Tree block only
1304 	 *         EXTENT_DATA_REF	Data only
1305 	 *         SHARED_DATA_REF	Data only
1306 	 *    2.2) Ref type specific data
1307 	 *         Either using btrfs_extent_inline_ref::offset, or specific
1308 	 *         data structure.
1309 	 */
1310 	if (unlikely(item_size < sizeof(*ei))) {
1311 		extent_err(leaf, slot,
1312 			   "invalid item size, have %u expect [%zu, %u)",
1313 			   item_size, sizeof(*ei),
1314 			   BTRFS_LEAF_DATA_SIZE(fs_info));
1315 		return -EUCLEAN;
1316 	}
1317 	end = item_size + btrfs_item_ptr_offset(leaf, slot);
1318 
1319 	/* Checks against extent_item */
1320 	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
1321 	flags = btrfs_extent_flags(leaf, ei);
1322 	total_refs = btrfs_extent_refs(leaf, ei);
1323 	generation = btrfs_extent_generation(leaf, ei);
1324 	if (unlikely(generation >
1325 		     btrfs_super_generation(fs_info->super_copy) + 1)) {
1326 		extent_err(leaf, slot,
1327 			   "invalid generation, have %llu expect (0, %llu]",
1328 			   generation,
1329 			   btrfs_super_generation(fs_info->super_copy) + 1);
1330 		return -EUCLEAN;
1331 	}
1332 	if (unlikely(!has_single_bit_set(flags & (BTRFS_EXTENT_FLAG_DATA |
1333 						  BTRFS_EXTENT_FLAG_TREE_BLOCK)))) {
1334 		extent_err(leaf, slot,
1335 		"invalid extent flag, have 0x%llx expect 1 bit set in 0x%llx",
1336 			flags, BTRFS_EXTENT_FLAG_DATA |
1337 			BTRFS_EXTENT_FLAG_TREE_BLOCK);
1338 		return -EUCLEAN;
1339 	}
1340 	is_tree_block = !!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK);
1341 	if (is_tree_block) {
1342 		if (unlikely(key->type == BTRFS_EXTENT_ITEM_KEY &&
1343 			     key->offset != fs_info->nodesize)) {
1344 			extent_err(leaf, slot,
1345 				   "invalid extent length, have %llu expect %u",
1346 				   key->offset, fs_info->nodesize);
1347 			return -EUCLEAN;
1348 		}
1349 	} else {
1350 		if (unlikely(key->type != BTRFS_EXTENT_ITEM_KEY)) {
1351 			extent_err(leaf, slot,
1352 			"invalid key type, have %u expect %u for data backref",
1353 				   key->type, BTRFS_EXTENT_ITEM_KEY);
1354 			return -EUCLEAN;
1355 		}
1356 		if (unlikely(!IS_ALIGNED(key->offset, fs_info->sectorsize))) {
1357 			extent_err(leaf, slot,
1358 			"invalid extent length, have %llu expect aligned to %u",
1359 				   key->offset, fs_info->sectorsize);
1360 			return -EUCLEAN;
1361 		}
1362 		if (unlikely(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
1363 			extent_err(leaf, slot,
1364 			"invalid extent flag, data has full backref set");
1365 			return -EUCLEAN;
1366 		}
1367 	}
1368 	ptr = (unsigned long)(struct btrfs_extent_item *)(ei + 1);
1369 
1370 	/* Check the special case of btrfs_tree_block_info */
1371 	if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
1372 		struct btrfs_tree_block_info *info;
1373 
1374 		info = (struct btrfs_tree_block_info *)ptr;
1375 		if (unlikely(btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL)) {
1376 			extent_err(leaf, slot,
1377 			"invalid tree block info level, have %u expect [0, %u]",
1378 				   btrfs_tree_block_level(leaf, info),
1379 				   BTRFS_MAX_LEVEL - 1);
1380 			return -EUCLEAN;
1381 		}
1382 		ptr = (unsigned long)(struct btrfs_tree_block_info *)(info + 1);
1383 	}
1384 
1385 	/* Check inline refs */
1386 	while (ptr < end) {
1387 		struct btrfs_extent_inline_ref *iref;
1388 		struct btrfs_extent_data_ref *dref;
1389 		struct btrfs_shared_data_ref *sref;
1390 		u64 dref_offset;
1391 		u64 inline_offset;
1392 		u8 inline_type;
1393 
1394 		if (unlikely(ptr + sizeof(*iref) > end)) {
1395 			extent_err(leaf, slot,
1396 "inline ref item overflows extent item, ptr %lu iref size %zu end %lu",
1397 				   ptr, sizeof(*iref), end);
1398 			return -EUCLEAN;
1399 		}
1400 		iref = (struct btrfs_extent_inline_ref *)ptr;
1401 		inline_type = btrfs_extent_inline_ref_type(leaf, iref);
1402 		inline_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1403 		if (unlikely(ptr + btrfs_extent_inline_ref_size(inline_type) > end)) {
1404 			extent_err(leaf, slot,
1405 "inline ref item overflows extent item, ptr %lu iref size %u end %lu",
1406 				   ptr, inline_type, end);
1407 			return -EUCLEAN;
1408 		}
1409 
1410 		switch (inline_type) {
1411 		/* inline_offset is subvolid of the owner, no need to check */
1412 		case BTRFS_TREE_BLOCK_REF_KEY:
1413 			inline_refs++;
1414 			break;
1415 		/* Contains parent bytenr */
1416 		case BTRFS_SHARED_BLOCK_REF_KEY:
1417 			if (unlikely(!IS_ALIGNED(inline_offset,
1418 						 fs_info->sectorsize))) {
1419 				extent_err(leaf, slot,
1420 		"invalid tree parent bytenr, have %llu expect aligned to %u",
1421 					   inline_offset, fs_info->sectorsize);
1422 				return -EUCLEAN;
1423 			}
1424 			inline_refs++;
1425 			break;
1426 		/*
1427 		 * Contains owner subvolid, owner key objectid, adjusted offset.
1428 		 * The only obvious corruption can happen in that offset.
1429 		 */
1430 		case BTRFS_EXTENT_DATA_REF_KEY:
1431 			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1432 			dref_offset = btrfs_extent_data_ref_offset(leaf, dref);
1433 			if (unlikely(!IS_ALIGNED(dref_offset,
1434 						 fs_info->sectorsize))) {
1435 				extent_err(leaf, slot,
1436 		"invalid data ref offset, have %llu expect aligned to %u",
1437 					   dref_offset, fs_info->sectorsize);
1438 				return -EUCLEAN;
1439 			}
1440 			inline_refs += btrfs_extent_data_ref_count(leaf, dref);
1441 			break;
1442 		/* Contains parent bytenr and ref count */
1443 		case BTRFS_SHARED_DATA_REF_KEY:
1444 			sref = (struct btrfs_shared_data_ref *)(iref + 1);
1445 			if (unlikely(!IS_ALIGNED(inline_offset,
1446 						 fs_info->sectorsize))) {
1447 				extent_err(leaf, slot,
1448 		"invalid data parent bytenr, have %llu expect aligned to %u",
1449 					   inline_offset, fs_info->sectorsize);
1450 				return -EUCLEAN;
1451 			}
1452 			inline_refs += btrfs_shared_data_ref_count(leaf, sref);
1453 			break;
1454 		default:
1455 			extent_err(leaf, slot, "unknown inline ref type: %u",
1456 				   inline_type);
1457 			return -EUCLEAN;
1458 		}
1459 		ptr += btrfs_extent_inline_ref_size(inline_type);
1460 	}
1461 	/* No padding is allowed */
1462 	if (unlikely(ptr != end)) {
1463 		extent_err(leaf, slot,
1464 			   "invalid extent item size, padding bytes found");
1465 		return -EUCLEAN;
1466 	}
1467 
1468 	/* Finally, check the inline refs against total refs */
1469 	if (unlikely(inline_refs > total_refs)) {
1470 		extent_err(leaf, slot,
1471 			"invalid extent refs, have %llu expect >= inline %llu",
1472 			   total_refs, inline_refs);
1473 		return -EUCLEAN;
1474 	}
1475 
1476 	if ((prev_key->type == BTRFS_EXTENT_ITEM_KEY) ||
1477 	    (prev_key->type == BTRFS_METADATA_ITEM_KEY)) {
1478 		u64 prev_end = prev_key->objectid;
1479 
1480 		if (prev_key->type == BTRFS_METADATA_ITEM_KEY)
1481 			prev_end += fs_info->nodesize;
1482 		else
1483 			prev_end += prev_key->offset;
1484 
1485 		if (unlikely(prev_end > key->objectid)) {
1486 			extent_err(leaf, slot,
1487 	"previous extent [%llu %u %llu] overlaps current extent [%llu %u %llu]",
1488 				   prev_key->objectid, prev_key->type,
1489 				   prev_key->offset, key->objectid, key->type,
1490 				   key->offset);
1491 			return -EUCLEAN;
1492 		}
1493 	}
1494 
1495 	return 0;
1496 }
1497 
1498 static int check_simple_keyed_refs(struct extent_buffer *leaf,
1499 				   struct btrfs_key *key, int slot)
1500 {
1501 	u32 expect_item_size = 0;
1502 
1503 	if (key->type == BTRFS_SHARED_DATA_REF_KEY)
1504 		expect_item_size = sizeof(struct btrfs_shared_data_ref);
1505 
1506 	if (unlikely(btrfs_item_size(leaf, slot) != expect_item_size)) {
1507 		generic_err(leaf, slot,
1508 		"invalid item size, have %u expect %u for key type %u",
1509 			    btrfs_item_size(leaf, slot),
1510 			    expect_item_size, key->type);
1511 		return -EUCLEAN;
1512 	}
1513 	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
1514 		generic_err(leaf, slot,
1515 "invalid key objectid for shared block ref, have %llu expect aligned to %u",
1516 			    key->objectid, leaf->fs_info->sectorsize);
1517 		return -EUCLEAN;
1518 	}
1519 	if (unlikely(key->type != BTRFS_TREE_BLOCK_REF_KEY &&
1520 		     !IS_ALIGNED(key->offset, leaf->fs_info->sectorsize))) {
1521 		extent_err(leaf, slot,
1522 		"invalid tree parent bytenr, have %llu expect aligned to %u",
1523 			   key->offset, leaf->fs_info->sectorsize);
1524 		return -EUCLEAN;
1525 	}
1526 	return 0;
1527 }
1528 
1529 static int check_extent_data_ref(struct extent_buffer *leaf,
1530 				 struct btrfs_key *key, int slot)
1531 {
1532 	struct btrfs_extent_data_ref *dref;
1533 	unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);
1534 	const unsigned long end = ptr + btrfs_item_size(leaf, slot);
1535 
1536 	if (unlikely(btrfs_item_size(leaf, slot) % sizeof(*dref) != 0)) {
1537 		generic_err(leaf, slot,
1538 	"invalid item size, have %u expect aligned to %zu for key type %u",
1539 			    btrfs_item_size(leaf, slot),
1540 			    sizeof(*dref), key->type);
1541 		return -EUCLEAN;
1542 	}
1543 	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
1544 		generic_err(leaf, slot,
1545 "invalid key objectid for shared block ref, have %llu expect aligned to %u",
1546 			    key->objectid, leaf->fs_info->sectorsize);
1547 		return -EUCLEAN;
1548 	}
1549 	for (; ptr < end; ptr += sizeof(*dref)) {
1550 		u64 offset;
1551 
1552 		/*
1553 		 * We cannot check the extent_data_ref hash due to possible
1554 		 * overflow from the leaf due to hash collisions.
1555 		 */
1556 		dref = (struct btrfs_extent_data_ref *)ptr;
1557 		offset = btrfs_extent_data_ref_offset(leaf, dref);
1558 		if (unlikely(!IS_ALIGNED(offset, leaf->fs_info->sectorsize))) {
1559 			extent_err(leaf, slot,
1560 	"invalid extent data backref offset, have %llu expect aligned to %u",
1561 				   offset, leaf->fs_info->sectorsize);
1562 			return -EUCLEAN;
1563 		}
1564 	}
1565 	return 0;
1566 }
1567 
1568 #define inode_ref_err(eb, slot, fmt, args...)			\
1569 	inode_item_err(eb, slot, fmt, ##args)
1570 static int check_inode_ref(struct extent_buffer *leaf,
1571 			   struct btrfs_key *key, struct btrfs_key *prev_key,
1572 			   int slot)
1573 {
1574 	struct btrfs_inode_ref *iref;
1575 	unsigned long ptr;
1576 	unsigned long end;
1577 
1578 	if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
1579 		return -EUCLEAN;
1580 	/* namelen can't be 0, so item_size == sizeof() is also invalid */
1581 	if (unlikely(btrfs_item_size(leaf, slot) <= sizeof(*iref))) {
1582 		inode_ref_err(leaf, slot,
1583 			"invalid item size, have %u expect (%zu, %u)",
1584 			btrfs_item_size(leaf, slot),
1585 			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
1586 		return -EUCLEAN;
1587 	}
1588 
1589 	ptr = btrfs_item_ptr_offset(leaf, slot);
1590 	end = ptr + btrfs_item_size(leaf, slot);
1591 	while (ptr < end) {
1592 		u16 namelen;
1593 
1594 		if (unlikely(ptr + sizeof(iref) > end)) {
1595 			inode_ref_err(leaf, slot,
1596 			"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
1597 				ptr, end, sizeof(iref));
1598 			return -EUCLEAN;
1599 		}
1600 
1601 		iref = (struct btrfs_inode_ref *)ptr;
1602 		namelen = btrfs_inode_ref_name_len(leaf, iref);
1603 		if (unlikely(ptr + sizeof(*iref) + namelen > end)) {
1604 			inode_ref_err(leaf, slot,
1605 				"inode ref overflow, ptr %lu end %lu namelen %u",
1606 				ptr, end, namelen);
1607 			return -EUCLEAN;
1608 		}
1609 
1610 		/*
1611 		 * NOTE: In theory we should record all found index numbers
1612 		 * to find any duplicated indexes, but that will be too time
1613 		 * consuming for inodes with too many hard links.
1614 		 */
1615 		ptr += sizeof(*iref) + namelen;
1616 	}
1617 	return 0;
1618 }
1619 
1620 /*
1621  * Common point to switch the item-specific validation.
1622  */
1623 static enum btrfs_tree_block_status check_leaf_item(struct extent_buffer *leaf,
1624 						    struct btrfs_key *key,
1625 						    int slot,
1626 						    struct btrfs_key *prev_key)
1627 {
1628 	int ret = 0;
1629 	struct btrfs_chunk *chunk;
1630 
1631 	switch (key->type) {
1632 	case BTRFS_EXTENT_DATA_KEY:
1633 		ret = check_extent_data_item(leaf, key, slot, prev_key);
1634 		break;
1635 	case BTRFS_EXTENT_CSUM_KEY:
1636 		ret = check_csum_item(leaf, key, slot, prev_key);
1637 		break;
1638 	case BTRFS_DIR_ITEM_KEY:
1639 	case BTRFS_DIR_INDEX_KEY:
1640 	case BTRFS_XATTR_ITEM_KEY:
1641 		ret = check_dir_item(leaf, key, prev_key, slot);
1642 		break;
1643 	case BTRFS_INODE_REF_KEY:
1644 		ret = check_inode_ref(leaf, key, prev_key, slot);
1645 		break;
1646 	case BTRFS_BLOCK_GROUP_ITEM_KEY:
1647 		ret = check_block_group_item(leaf, key, slot);
1648 		break;
1649 	case BTRFS_CHUNK_ITEM_KEY:
1650 		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1651 		ret = check_leaf_chunk_item(leaf, chunk, key, slot);
1652 		break;
1653 	case BTRFS_DEV_ITEM_KEY:
1654 		ret = check_dev_item(leaf, key, slot);
1655 		break;
1656 	case BTRFS_INODE_ITEM_KEY:
1657 		ret = check_inode_item(leaf, key, slot);
1658 		break;
1659 	case BTRFS_ROOT_ITEM_KEY:
1660 		ret = check_root_item(leaf, key, slot);
1661 		break;
1662 	case BTRFS_EXTENT_ITEM_KEY:
1663 	case BTRFS_METADATA_ITEM_KEY:
1664 		ret = check_extent_item(leaf, key, slot, prev_key);
1665 		break;
1666 	case BTRFS_TREE_BLOCK_REF_KEY:
1667 	case BTRFS_SHARED_DATA_REF_KEY:
1668 	case BTRFS_SHARED_BLOCK_REF_KEY:
1669 		ret = check_simple_keyed_refs(leaf, key, slot);
1670 		break;
1671 	case BTRFS_EXTENT_DATA_REF_KEY:
1672 		ret = check_extent_data_ref(leaf, key, slot);
1673 		break;
1674 	}
1675 
1676 	if (ret)
1677 		return BTRFS_TREE_BLOCK_INVALID_ITEM;
1678 	return BTRFS_TREE_BLOCK_CLEAN;
1679 }
1680 
1681 enum btrfs_tree_block_status __btrfs_check_leaf(struct extent_buffer *leaf)
1682 {
1683 	struct btrfs_fs_info *fs_info = leaf->fs_info;
1684 	/* No valid key type is 0, so all key should be larger than this key */
1685 	struct btrfs_key prev_key = {0, 0, 0};
1686 	struct btrfs_key key;
1687 	u32 nritems = btrfs_header_nritems(leaf);
1688 	int slot;
1689 
1690 	if (unlikely(btrfs_header_level(leaf) != 0)) {
1691 		generic_err(leaf, 0,
1692 			"invalid level for leaf, have %d expect 0",
1693 			btrfs_header_level(leaf));
1694 		return BTRFS_TREE_BLOCK_INVALID_LEVEL;
1695 	}
1696 
1697 	/*
1698 	 * Extent buffers from a relocation tree have a owner field that
1699 	 * corresponds to the subvolume tree they are based on. So just from an
1700 	 * extent buffer alone we can not find out what is the id of the
1701 	 * corresponding subvolume tree, so we can not figure out if the extent
1702 	 * buffer corresponds to the root of the relocation tree or not. So
1703 	 * skip this check for relocation trees.
1704 	 */
1705 	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
1706 		u64 owner = btrfs_header_owner(leaf);
1707 
1708 		/* These trees must never be empty */
1709 		if (unlikely(owner == BTRFS_ROOT_TREE_OBJECTID ||
1710 			     owner == BTRFS_CHUNK_TREE_OBJECTID ||
1711 			     owner == BTRFS_DEV_TREE_OBJECTID ||
1712 			     owner == BTRFS_FS_TREE_OBJECTID ||
1713 			     owner == BTRFS_DATA_RELOC_TREE_OBJECTID)) {
1714 			generic_err(leaf, 0,
1715 			"invalid root, root %llu must never be empty",
1716 				    owner);
1717 			return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
1718 		}
1719 
1720 		/* Unknown tree */
1721 		if (unlikely(owner == 0)) {
1722 			generic_err(leaf, 0,
1723 				"invalid owner, root 0 is not defined");
1724 			return BTRFS_TREE_BLOCK_INVALID_OWNER;
1725 		}
1726 
1727 		/* EXTENT_TREE_V2 can have empty extent trees. */
1728 		if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
1729 			return BTRFS_TREE_BLOCK_CLEAN;
1730 
1731 		if (unlikely(owner == BTRFS_EXTENT_TREE_OBJECTID)) {
1732 			generic_err(leaf, 0,
1733 			"invalid root, root %llu must never be empty",
1734 				    owner);
1735 			return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
1736 		}
1737 
1738 		return BTRFS_TREE_BLOCK_CLEAN;
1739 	}
1740 
1741 	if (unlikely(nritems == 0))
1742 		return BTRFS_TREE_BLOCK_CLEAN;
1743 
1744 	/*
1745 	 * Check the following things to make sure this is a good leaf, and
1746 	 * leaf users won't need to bother with similar sanity checks:
1747 	 *
1748 	 * 1) key ordering
1749 	 * 2) item offset and size
1750 	 *    No overlap, no hole, all inside the leaf.
1751 	 * 3) item content
1752 	 *    If possible, do comprehensive sanity check.
1753 	 *    NOTE: All checks must only rely on the item data itself.
1754 	 */
1755 	for (slot = 0; slot < nritems; slot++) {
1756 		u32 item_end_expected;
1757 		u64 item_data_end;
1758 
1759 		btrfs_item_key_to_cpu(leaf, &key, slot);
1760 
1761 		/* Make sure the keys are in the right order */
1762 		if (unlikely(btrfs_comp_cpu_keys(&prev_key, &key) >= 0)) {
1763 			generic_err(leaf, slot,
1764 	"bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
1765 				prev_key.objectid, prev_key.type,
1766 				prev_key.offset, key.objectid, key.type,
1767 				key.offset);
1768 			return BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
1769 		}
1770 
1771 		item_data_end = (u64)btrfs_item_offset(leaf, slot) +
1772 				btrfs_item_size(leaf, slot);
1773 		/*
1774 		 * Make sure the offset and ends are right, remember that the
1775 		 * item data starts at the end of the leaf and grows towards the
1776 		 * front.
1777 		 */
1778 		if (slot == 0)
1779 			item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
1780 		else
1781 			item_end_expected = btrfs_item_offset(leaf,
1782 								 slot - 1);
1783 		if (unlikely(item_data_end != item_end_expected)) {
1784 			generic_err(leaf, slot,
1785 				"unexpected item end, have %llu expect %u",
1786 				item_data_end, item_end_expected);
1787 			return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
1788 		}
1789 
1790 		/*
1791 		 * Check to make sure that we don't point outside of the leaf,
1792 		 * just in case all the items are consistent to each other, but
1793 		 * all point outside of the leaf.
1794 		 */
1795 		if (unlikely(item_data_end > BTRFS_LEAF_DATA_SIZE(fs_info))) {
1796 			generic_err(leaf, slot,
1797 			"slot end outside of leaf, have %llu expect range [0, %u]",
1798 				item_data_end, BTRFS_LEAF_DATA_SIZE(fs_info));
1799 			return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
1800 		}
1801 
1802 		/* Also check if the item pointer overlaps with btrfs item. */
1803 		if (unlikely(btrfs_item_ptr_offset(leaf, slot) <
1804 			     btrfs_item_nr_offset(leaf, slot) + sizeof(struct btrfs_item))) {
1805 			generic_err(leaf, slot,
1806 		"slot overlaps with its data, item end %lu data start %lu",
1807 				btrfs_item_nr_offset(leaf, slot) +
1808 				sizeof(struct btrfs_item),
1809 				btrfs_item_ptr_offset(leaf, slot));
1810 			return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
1811 		}
1812 
1813 		/*
1814 		 * We only want to do this if WRITTEN is set, otherwise the leaf
1815 		 * may be in some intermediate state and won't appear valid.
1816 		 */
1817 		if (btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_WRITTEN)) {
1818 			enum btrfs_tree_block_status ret;
1819 
1820 			/*
1821 			 * Check if the item size and content meet other
1822 			 * criteria
1823 			 */
1824 			ret = check_leaf_item(leaf, &key, slot, &prev_key);
1825 			if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
1826 				return ret;
1827 		}
1828 
1829 		prev_key.objectid = key.objectid;
1830 		prev_key.type = key.type;
1831 		prev_key.offset = key.offset;
1832 	}
1833 
1834 	return BTRFS_TREE_BLOCK_CLEAN;
1835 }
1836 
1837 int btrfs_check_leaf(struct extent_buffer *leaf)
1838 {
1839 	enum btrfs_tree_block_status ret;
1840 
1841 	ret = __btrfs_check_leaf(leaf);
1842 	if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
1843 		return -EUCLEAN;
1844 	return 0;
1845 }
1846 ALLOW_ERROR_INJECTION(btrfs_check_leaf, ERRNO);
1847 
1848 enum btrfs_tree_block_status __btrfs_check_node(struct extent_buffer *node)
1849 {
1850 	struct btrfs_fs_info *fs_info = node->fs_info;
1851 	unsigned long nr = btrfs_header_nritems(node);
1852 	struct btrfs_key key, next_key;
1853 	int slot;
1854 	int level = btrfs_header_level(node);
1855 	u64 bytenr;
1856 
1857 	if (unlikely(level <= 0 || level >= BTRFS_MAX_LEVEL)) {
1858 		generic_err(node, 0,
1859 			"invalid level for node, have %d expect [1, %d]",
1860 			level, BTRFS_MAX_LEVEL - 1);
1861 		return BTRFS_TREE_BLOCK_INVALID_LEVEL;
1862 	}
1863 	if (unlikely(nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info))) {
1864 		btrfs_crit(fs_info,
1865 "corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
1866 			   btrfs_header_owner(node), node->start,
1867 			   nr == 0 ? "small" : "large", nr,
1868 			   BTRFS_NODEPTRS_PER_BLOCK(fs_info));
1869 		return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
1870 	}
1871 
1872 	for (slot = 0; slot < nr - 1; slot++) {
1873 		bytenr = btrfs_node_blockptr(node, slot);
1874 		btrfs_node_key_to_cpu(node, &key, slot);
1875 		btrfs_node_key_to_cpu(node, &next_key, slot + 1);
1876 
1877 		if (unlikely(!bytenr)) {
1878 			generic_err(node, slot,
1879 				"invalid NULL node pointer");
1880 			return BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
1881 		}
1882 		if (unlikely(!IS_ALIGNED(bytenr, fs_info->sectorsize))) {
1883 			generic_err(node, slot,
1884 			"unaligned pointer, have %llu should be aligned to %u",
1885 				bytenr, fs_info->sectorsize);
1886 			return BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
1887 		}
1888 
1889 		if (unlikely(btrfs_comp_cpu_keys(&key, &next_key) >= 0)) {
1890 			generic_err(node, slot,
1891 	"bad key order, current (%llu %u %llu) next (%llu %u %llu)",
1892 				key.objectid, key.type, key.offset,
1893 				next_key.objectid, next_key.type,
1894 				next_key.offset);
1895 			return BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
1896 		}
1897 	}
1898 	return BTRFS_TREE_BLOCK_CLEAN;
1899 }
1900 
1901 int btrfs_check_node(struct extent_buffer *node)
1902 {
1903 	enum btrfs_tree_block_status ret;
1904 
1905 	ret = __btrfs_check_node(node);
1906 	if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
1907 		return -EUCLEAN;
1908 	return 0;
1909 }
1910 ALLOW_ERROR_INJECTION(btrfs_check_node, ERRNO);
1911 
1912 int btrfs_check_eb_owner(const struct extent_buffer *eb, u64 root_owner)
1913 {
1914 	const bool is_subvol = is_fstree(root_owner);
1915 	const u64 eb_owner = btrfs_header_owner(eb);
1916 
1917 	/*
1918 	 * Skip dummy fs, as selftests don't create unique ebs for each dummy
1919 	 * root.
1920 	 */
1921 	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &eb->fs_info->fs_state))
1922 		return 0;
1923 	/*
1924 	 * There are several call sites (backref walking, qgroup, and data
1925 	 * reloc) passing 0 as @root_owner, as they are not holding the
1926 	 * tree root.  In that case, we can not do a reliable ownership check,
1927 	 * so just exit.
1928 	 */
1929 	if (root_owner == 0)
1930 		return 0;
1931 	/*
1932 	 * These trees use key.offset as their owner, our callers don't have
1933 	 * the extra capacity to pass key.offset here.  So we just skip them.
1934 	 */
1935 	if (root_owner == BTRFS_TREE_LOG_OBJECTID ||
1936 	    root_owner == BTRFS_TREE_RELOC_OBJECTID)
1937 		return 0;
1938 
1939 	if (!is_subvol) {
1940 		/* For non-subvolume trees, the eb owner should match root owner */
1941 		if (unlikely(root_owner != eb_owner)) {
1942 			btrfs_crit(eb->fs_info,
1943 "corrupted %s, root=%llu block=%llu owner mismatch, have %llu expect %llu",
1944 				btrfs_header_level(eb) == 0 ? "leaf" : "node",
1945 				root_owner, btrfs_header_bytenr(eb), eb_owner,
1946 				root_owner);
1947 			return -EUCLEAN;
1948 		}
1949 		return 0;
1950 	}
1951 
1952 	/*
1953 	 * For subvolume trees, owners can mismatch, but they should all belong
1954 	 * to subvolume trees.
1955 	 */
1956 	if (unlikely(is_subvol != is_fstree(eb_owner))) {
1957 		btrfs_crit(eb->fs_info,
1958 "corrupted %s, root=%llu block=%llu owner mismatch, have %llu expect [%llu, %llu]",
1959 			btrfs_header_level(eb) == 0 ? "leaf" : "node",
1960 			root_owner, btrfs_header_bytenr(eb), eb_owner,
1961 			BTRFS_FIRST_FREE_OBJECTID, BTRFS_LAST_FREE_OBJECTID);
1962 		return -EUCLEAN;
1963 	}
1964 	return 0;
1965 }
1966 
1967 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
1968 			   struct btrfs_key *first_key, u64 parent_transid)
1969 {
1970 	struct btrfs_fs_info *fs_info = eb->fs_info;
1971 	int found_level;
1972 	struct btrfs_key found_key;
1973 	int ret;
1974 
1975 	found_level = btrfs_header_level(eb);
1976 	if (found_level != level) {
1977 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
1978 		     KERN_ERR "BTRFS: tree level check failed\n");
1979 		btrfs_err(fs_info,
1980 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
1981 			  eb->start, level, found_level);
1982 		return -EIO;
1983 	}
1984 
1985 	if (!first_key)
1986 		return 0;
1987 
1988 	/*
1989 	 * For live tree block (new tree blocks in current transaction),
1990 	 * we need proper lock context to avoid race, which is impossible here.
1991 	 * So we only checks tree blocks which is read from disk, whose
1992 	 * generation <= fs_info->last_trans_committed.
1993 	 */
1994 	if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
1995 		return 0;
1996 
1997 	/* We have @first_key, so this @eb must have at least one item */
1998 	if (btrfs_header_nritems(eb) == 0) {
1999 		btrfs_err(fs_info,
2000 		"invalid tree nritems, bytenr=%llu nritems=0 expect >0",
2001 			  eb->start);
2002 		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
2003 		return -EUCLEAN;
2004 	}
2005 
2006 	if (found_level)
2007 		btrfs_node_key_to_cpu(eb, &found_key, 0);
2008 	else
2009 		btrfs_item_key_to_cpu(eb, &found_key, 0);
2010 	ret = btrfs_comp_cpu_keys(first_key, &found_key);
2011 
2012 	if (ret) {
2013 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
2014 		     KERN_ERR "BTRFS: tree first key check failed\n");
2015 		btrfs_err(fs_info,
2016 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
2017 			  eb->start, parent_transid, first_key->objectid,
2018 			  first_key->type, first_key->offset,
2019 			  found_key.objectid, found_key.type,
2020 			  found_key.offset);
2021 	}
2022 	return ret;
2023 }
2024