fs/btrfs/tree-checker.c - arm/linux - Git at Google

 /*
  * Copyright (C) Qu Wenruo 2017.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
  * License v2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public
  * License along with this program.
  */

 /*
  * The module is used to catch unexpected/corrupted tree block data.
  * Such behavior can be caused either by a fuzzed image or bugs.
  *
  * The objective is to do leaf/node validation checks when tree block is read
  * from disk, and check *every* possible member, so other code won't
  * need to checking them again.
  *
  * Due to the potential and unwanted damage, every checker needs to be
  * carefully reviewed otherwise so it does not prevent mount of valid images.
  */

 #include "ctree.h"
 #include "tree-checker.h"
 #include "disk-io.h"
 #include "compression.h"

 /*
  * Error message should follow the following format:
  * corrupt <type>: <identifier>, <reason>[, <bad_value>]
  *
  * @type:	leaf or node
  * @identifier:	the necessary info to locate the leaf/node.
  * 		It's recommened to decode key.objecitd/offset if it's
  * 		meaningful.
  * @reason:	describe the error
  * @bad_value:	optional, it's recommened to output bad value and its
  *		expected value (range).
  *
  * Since comma is used to separate the components, only space is allowed
  * inside each component.
  */

 /*
  * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
  * Allows callers to customize the output.
  */
 __printf(4, 5)
 static void generic_err(const struct btrfs_root *root,
 			const struct extent_buffer *eb, int slot,
 			const char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list args;

 	va_start(args, fmt);

 	vaf.fmt = fmt;
 	vaf.va = &args;

 	btrfs_crit(root->fs_info,
 		"corrupt %s: root=%llu block=%llu slot=%d, %pV",
 		btrfs_header_level(eb) == 0 ? "leaf" : "node",
 		root->objectid, btrfs_header_bytenr(eb), slot, &vaf);
 	va_end(args);
 }

 /*
  * Customized reporter for extent data item, since its key objectid and
  * offset has its own meaning.
  */
 __printf(4, 5)
 static void file_extent_err(const struct btrfs_root *root,
 			    const struct extent_buffer *eb, int slot,
 			    const char *fmt, ...)
 {
 	struct btrfs_key key;
 	struct va_format vaf;
 	va_list args;

 	btrfs_item_key_to_cpu(eb, &key, slot);
 	va_start(args, fmt);

 	vaf.fmt = fmt;
 	vaf.va = &args;

 	btrfs_crit(root->fs_info,
 	"corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
 		btrfs_header_level(eb) == 0 ? "leaf" : "node", root->objectid,
 		btrfs_header_bytenr(eb), slot, key.objectid, key.offset, &vaf);
 	va_end(args);
 }

 /*
  * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
  * Else return 1
  */
 #define CHECK_FE_ALIGNED(root, leaf, slot, fi, name, alignment)		      \
 ({									      \
 	if (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))) \
 		file_extent_err((root), (leaf), (slot),			      \
 	"invalid %s for file extent, have %llu, should be aligned to %u",     \
 			(#name), btrfs_file_extent_##name((leaf), (fi)),      \
 			(alignment));					      \
 	(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment)));   \
 })

 static int check_extent_data_item(struct btrfs_root *root,
 				  struct extent_buffer *leaf,
 				  struct btrfs_key *key, int slot)
 {
 	struct btrfs_file_extent_item *fi;
 	u32 sectorsize = root->fs_info->sectorsize;
 	u32 item_size = btrfs_item_size_nr(leaf, slot);

 	if (!IS_ALIGNED(key->offset, sectorsize)) {
 		file_extent_err(root, leaf, slot,
 "unaligned file_offset for file extent, have %llu should be aligned to %u",
 			key->offset, sectorsize);
 		return -EUCLEAN;
 	}

 	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);

 	if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
 		file_extent_err(root, leaf, slot,
 		"invalid type for file extent, have %u expect range [0, %u]",
 			btrfs_file_extent_type(leaf, fi),
 			BTRFS_FILE_EXTENT_TYPES);
 		return -EUCLEAN;
 	}

 	/*
 	 * Support for new compression/encrption must introduce incompat flag,
 	 * and must be caught in open_ctree().
 	 */
 	if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) {
 		file_extent_err(root, leaf, slot,
 	"invalid compression for file extent, have %u expect range [0, %u]",
 			btrfs_file_extent_compression(leaf, fi),
 			BTRFS_COMPRESS_TYPES);
 		return -EUCLEAN;
 	}
 	if (btrfs_file_extent_encryption(leaf, fi)) {
 		file_extent_err(root, leaf, slot,
 			"invalid encryption for file extent, have %u expect 0",
 			btrfs_file_extent_encryption(leaf, fi));
 		return -EUCLEAN;
 	}
 	if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
 		/* Inline extent must have 0 as key offset */
 		if (key->offset) {
 			file_extent_err(root, leaf, slot,
 		"invalid file_offset for inline file extent, have %llu expect 0",
 				key->offset);
 			return -EUCLEAN;
 		}

 		/* Compressed inline extent has no on-disk size, skip it */
 		if (btrfs_file_extent_compression(leaf, fi) !=
 		    BTRFS_COMPRESS_NONE)
 			return 0;

 		/* Uncompressed inline extent size must match item size */
 		if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
 		    btrfs_file_extent_ram_bytes(leaf, fi)) {
 			file_extent_err(root, leaf, slot,
 	"invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
 				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
 				btrfs_file_extent_ram_bytes(leaf, fi));
 			return -EUCLEAN;
 		}
 		return 0;
 	}

 	/* Regular or preallocated extent has fixed item size */
 	if (item_size != sizeof(*fi)) {
 		file_extent_err(root, leaf, slot,
 	"invalid item size for reg/prealloc file extent, have %u expect %zu",
 			item_size, sizeof(*fi));
 		return -EUCLEAN;
 	}
 	if (CHECK_FE_ALIGNED(root, leaf, slot, fi, ram_bytes, sectorsize) ||
 	    CHECK_FE_ALIGNED(root, leaf, slot, fi, disk_bytenr, sectorsize) ||
 	    CHECK_FE_ALIGNED(root, leaf, slot, fi, disk_num_bytes, sectorsize) ||
 	    CHECK_FE_ALIGNED(root, leaf, slot, fi, offset, sectorsize) ||
 	    CHECK_FE_ALIGNED(root, leaf, slot, fi, num_bytes, sectorsize))
 		return -EUCLEAN;
 	return 0;
 }

 static int check_csum_item(struct btrfs_root *root, struct extent_buffer *leaf,
 			   struct btrfs_key *key, int slot)
 {
 	u32 sectorsize = root->fs_info->sectorsize;
 	u32 csumsize = btrfs_super_csum_size(root->fs_info->super_copy);

 	if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
 		generic_err(root, leaf, slot,
 		"invalid key objectid for csum item, have %llu expect %llu",
 			key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
 		return -EUCLEAN;
 	}
 	if (!IS_ALIGNED(key->offset, sectorsize)) {
 		generic_err(root, leaf, slot,
 	"unaligned key offset for csum item, have %llu should be aligned to %u",
 			key->offset, sectorsize);
 		return -EUCLEAN;
 	}
 	if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) {
 		generic_err(root, leaf, slot,
 	"unaligned item size for csum item, have %u should be aligned to %u",
 			btrfs_item_size_nr(leaf, slot), csumsize);
 		return -EUCLEAN;
 	}
 	return 0;
 }

 /*
  * Common point to switch the item-specific validation.
  */
 static int check_leaf_item(struct btrfs_root *root,
 			   struct extent_buffer *leaf,
 			   struct btrfs_key *key, int slot)
 {
 	int ret = 0;

 	switch (key->type) {
 	case BTRFS_EXTENT_DATA_KEY:
 		ret = check_extent_data_item(root, leaf, key, slot);
 		break;
 	case BTRFS_EXTENT_CSUM_KEY:
 		ret = check_csum_item(root, leaf, key, slot);
 		break;
 	}
 	return ret;
 }

 static int check_leaf(struct btrfs_root *root, struct extent_buffer *leaf,
 		      bool check_item_data)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	/* No valid key type is 0, so all key should be larger than this key */
 	struct btrfs_key prev_key = {0, 0, 0};
 	struct btrfs_key key;
 	u32 nritems = btrfs_header_nritems(leaf);
 	int slot;

 	/*
 	 * Extent buffers from a relocation tree have a owner field that
 	 * corresponds to the subvolume tree they are based on. So just from an
 	 * extent buffer alone we can not find out what is the id of the
 	 * corresponding subvolume tree, so we can not figure out if the extent
 	 * buffer corresponds to the root of the relocation tree or not. So
 	 * skip this check for relocation trees.
 	 */
 	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
 		struct btrfs_root *check_root;

 		key.objectid = btrfs_header_owner(leaf);
 		key.type = BTRFS_ROOT_ITEM_KEY;
 		key.offset = (u64)-1;

 		check_root = btrfs_get_fs_root(fs_info, &key, false);
 		/*
 		 * The only reason we also check NULL here is that during
 		 * open_ctree() some roots has not yet been set up.
 		 */
 		if (!IS_ERR_OR_NULL(check_root)) {
 			struct extent_buffer *eb;

 			eb = btrfs_root_node(check_root);
 			/* if leaf is the root, then it's fine */
 			if (leaf != eb) {
 				generic_err(check_root, leaf, 0,
 		"invalid nritems, have %u should not be 0 for non-root leaf",
 					nritems);
 				free_extent_buffer(eb);
 				return -EUCLEAN;
 			}
 			free_extent_buffer(eb);
 		}
 		return 0;
 	}

 	if (nritems == 0)
 		return 0;

 	/*
 	 * Check the following things to make sure this is a good leaf, and
 	 * leaf users won't need to bother with similar sanity checks:
 	 *
 	 * 1) key ordering
 	 * 2) item offset and size
 	 *    No overlap, no hole, all inside the leaf.
 	 * 3) item content
 	 *    If possible, do comprehensive sanity check.
 	 *    NOTE: All checks must only rely on the item data itself.
 	 */
 	for (slot = 0; slot < nritems; slot++) {
 		u32 item_end_expected;
 		int ret;

 		btrfs_item_key_to_cpu(leaf, &key, slot);

 		/* Make sure the keys are in the right order */
 		if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) {
 			generic_err(root, leaf, slot,
 	"bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
 				prev_key.objectid, prev_key.type,
 				prev_key.offset, key.objectid, key.type,
 				key.offset);
 			return -EUCLEAN;
 		}

 		/*
 		 * Make sure the offset and ends are right, remember that the
 		 * item data starts at the end of the leaf and grows towards the
 		 * front.
 		 */
 		if (slot == 0)
 			item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
 		else
 			item_end_expected = btrfs_item_offset_nr(leaf,
 								 slot - 1);
 		if (btrfs_item_end_nr(leaf, slot) != item_end_expected) {
 			generic_err(root, leaf, slot,
 				"unexpected item end, have %u expect %u",
 				btrfs_item_end_nr(leaf, slot),
 				item_end_expected);
 			return -EUCLEAN;
 		}

 		/*
 		 * Check to make sure that we don't point outside of the leaf,
 		 * just in case all the items are consistent to each other, but
 		 * all point outside of the leaf.
 		 */
 		if (btrfs_item_end_nr(leaf, slot) >
 		    BTRFS_LEAF_DATA_SIZE(fs_info)) {
 			generic_err(root, leaf, slot,
 			"slot end outside of leaf, have %u expect range [0, %u]",
 				btrfs_item_end_nr(leaf, slot),
 				BTRFS_LEAF_DATA_SIZE(fs_info));
 			return -EUCLEAN;
 		}

 		/* Also check if the item pointer overlaps with btrfs item. */
 		if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) >
 		    btrfs_item_ptr_offset(leaf, slot)) {
 			generic_err(root, leaf, slot,
 		"slot overlaps with its data, item end %lu data start %lu",
 				btrfs_item_nr_offset(slot) +
 				sizeof(struct btrfs_item),
 				btrfs_item_ptr_offset(leaf, slot));
 			return -EUCLEAN;
 		}

 		if (check_item_data) {
 			/*
 			 * Check if the item size and content meet other
 			 * criteria
 			 */
 			ret = check_leaf_item(root, leaf, &key, slot);
 			if (ret < 0)
 				return ret;
 		}

 		prev_key.objectid = key.objectid;
 		prev_key.type = key.type;
 		prev_key.offset = key.offset;
 	}

 	return 0;
 }

 int btrfs_check_leaf_full(struct btrfs_root *root, struct extent_buffer *leaf)
 {
 	return check_leaf(root, leaf, true);
 }

 int btrfs_check_leaf_relaxed(struct btrfs_root *root,
 			     struct extent_buffer *leaf)
 {
 	return check_leaf(root, leaf, false);
 }

 int btrfs_check_node(struct btrfs_root *root, struct extent_buffer *node)
 {
 	unsigned long nr = btrfs_header_nritems(node);
 	struct btrfs_key key, next_key;
 	int slot;
 	u64 bytenr;
 	int ret = 0;

 	if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root->fs_info)) {
 		btrfs_crit(root->fs_info,
 "corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
 			   root->objectid, node->start,
 			   nr == 0 ? "small" : "large", nr,
 			   BTRFS_NODEPTRS_PER_BLOCK(root->fs_info));
 		return -EUCLEAN;
 	}

 	for (slot = 0; slot < nr - 1; slot++) {
 		bytenr = btrfs_node_blockptr(node, slot);
 		btrfs_node_key_to_cpu(node, &key, slot);
 		btrfs_node_key_to_cpu(node, &next_key, slot + 1);

 		if (!bytenr) {
 			generic_err(root, node, slot,
 				"invalid NULL node pointer");
 			ret = -EUCLEAN;
 			goto out;
 		}
 		if (!IS_ALIGNED(bytenr, root->fs_info->sectorsize)) {
 			generic_err(root, node, slot,
 			"unaligned pointer, have %llu should be aligned to %u",
 				bytenr, root->fs_info->sectorsize);
 			ret = -EUCLEAN;
 			goto out;
 		}

 		if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
 			generic_err(root, node, slot,
 	"bad key order, current (%llu %u %llu) next (%llu %u %llu)",
 				key.objectid, key.type, key.offset,
 				next_key.objectid, next_key.type,
 				next_key.offset);
 			ret = -EUCLEAN;
 			goto out;
 		}
 	}
 out:
 	return ret;
 }
	/*
	* Copyright (C) Qu Wenruo 2017. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public
	* License v2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public
	* License along with this program.
	*/

	/*
	* The module is used to catch unexpected/corrupted tree block data.
	* Such behavior can be caused either by a fuzzed image or bugs.
	*
	* The objective is to do leaf/node validation checks when tree block is read
	* from disk, and check every possible member, so other code won't
	* need to checking them again.
	*
	* Due to the potential and unwanted damage, every checker needs to be
	* carefully reviewed otherwise so it does not prevent mount of valid images.
	*/

	#include "ctree.h"
	#include "tree-checker.h"
	#include "disk-io.h"
	#include "compression.h"

	/*
	* Error message should follow the following format:
	* corrupt <type>: <identifier>, <reason>[, <bad_value>]
	*
	* @type: leaf or node
	* @identifier: the necessary info to locate the leaf/node.
	* It's recommened to decode key.objecitd/offset if it's
	* meaningful.
	* @reason: describe the error
	* @bad_value: optional, it's recommened to output bad value and its
	* expected value (range).
	*
	* Since comma is used to separate the components, only space is allowed
	* inside each component.
	*/

	/*
	* Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
	* Allows callers to customize the output.
	*/
	__printf(4, 5)
	static void generic_err(const struct btrfs_root *root,
	const struct extent_buffer *eb, int slot,
	const char *fmt, ...)
	{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(root->fs_info,
	"corrupt %s: root=%llu block=%llu slot=%d, %pV",
	btrfs_header_level(eb) == 0 ? "leaf" : "node",
	root->objectid, btrfs_header_bytenr(eb), slot, &vaf);
	va_end(args);
	}

	/*
	* Customized reporter for extent data item, since its key objectid and
	* offset has its own meaning.
	*/
	__printf(4, 5)
	static void file_extent_err(const struct btrfs_root *root,
	const struct extent_buffer *eb, int slot,
	const char *fmt, ...)
	{
	struct btrfs_key key;
	struct va_format vaf;
	va_list args;

	btrfs_item_key_to_cpu(eb, &key, slot);
	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(root->fs_info,
	"corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
	btrfs_header_level(eb) == 0 ? "leaf" : "node", root->objectid,
	btrfs_header_bytenr(eb), slot, key.objectid, key.offset, &vaf);
	va_end(args);
	}

	/*
	* Return 0 if the btrfs_file_extent_##name is aligned to @alignment
	* Else return 1
	*/
	#define CHECK_FE_ALIGNED(root, leaf, slot, fi, name, alignment) \
	({ \
	if (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))) \
	file_extent_err((root), (leaf), (slot), \
	"invalid %s for file extent, have %llu, should be aligned to %u", \
	(#name), btrfs_file_extent_##name((leaf), (fi)), \
	(alignment)); \
	(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))); \
	})

	static int check_extent_data_item(struct btrfs_root *root,
	struct extent_buffer *leaf,
	struct btrfs_key *key, int slot)
	{
	struct btrfs_file_extent_item *fi;
	u32 sectorsize = root->fs_info->sectorsize;
	u32 item_size = btrfs_item_size_nr(leaf, slot);

	if (!IS_ALIGNED(key->offset, sectorsize)) {
	file_extent_err(root, leaf, slot,
	"unaligned file_offset for file extent, have %llu should be aligned to %u",
	key->offset, sectorsize);
	return -EUCLEAN;
	}

	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);

	if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
	file_extent_err(root, leaf, slot,
	"invalid type for file extent, have %u expect range [0, %u]",
	btrfs_file_extent_type(leaf, fi),
	BTRFS_FILE_EXTENT_TYPES);
	return -EUCLEAN;
	}

	/*
	* Support for new compression/encrption must introduce incompat flag,
	* and must be caught in open_ctree().
	*/
	if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) {
	file_extent_err(root, leaf, slot,
	"invalid compression for file extent, have %u expect range [0, %u]",
	btrfs_file_extent_compression(leaf, fi),
	BTRFS_COMPRESS_TYPES);
	return -EUCLEAN;
	}
	if (btrfs_file_extent_encryption(leaf, fi)) {
	file_extent_err(root, leaf, slot,
	"invalid encryption for file extent, have %u expect 0",
	btrfs_file_extent_encryption(leaf, fi));
	return -EUCLEAN;
	}
	if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
	/* Inline extent must have 0 as key offset */
	if (key->offset) {
	file_extent_err(root, leaf, slot,
	"invalid file_offset for inline file extent, have %llu expect 0",
	key->offset);
	return -EUCLEAN;
	}

	/* Compressed inline extent has no on-disk size, skip it */
	if (btrfs_file_extent_compression(leaf, fi) !=
	BTRFS_COMPRESS_NONE)
	return 0;

	/* Uncompressed inline extent size must match item size */
	if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
	btrfs_file_extent_ram_bytes(leaf, fi)) {
	file_extent_err(root, leaf, slot,
	"invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
	item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
	btrfs_file_extent_ram_bytes(leaf, fi));
	return -EUCLEAN;
	}
	return 0;
	}

	/* Regular or preallocated extent has fixed item size */
	if (item_size != sizeof(*fi)) {
	file_extent_err(root, leaf, slot,
	"invalid item size for reg/prealloc file extent, have %u expect %zu",
	item_size, sizeof(*fi));
	return -EUCLEAN;
	}
	if (CHECK_FE_ALIGNED(root, leaf, slot, fi, ram_bytes, sectorsize) \|\|
	CHECK_FE_ALIGNED(root, leaf, slot, fi, disk_bytenr, sectorsize) \|\|
	CHECK_FE_ALIGNED(root, leaf, slot, fi, disk_num_bytes, sectorsize) \|\|
	CHECK_FE_ALIGNED(root, leaf, slot, fi, offset, sectorsize) \|\|
	CHECK_FE_ALIGNED(root, leaf, slot, fi, num_bytes, sectorsize))
	return -EUCLEAN;
	return 0;
	}

	static int check_csum_item(struct btrfs_root root, struct extent_buffer leaf,
	struct btrfs_key *key, int slot)
	{
	u32 sectorsize = root->fs_info->sectorsize;
	u32 csumsize = btrfs_super_csum_size(root->fs_info->super_copy);

	if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
	generic_err(root, leaf, slot,
	"invalid key objectid for csum item, have %llu expect %llu",
	key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
	return -EUCLEAN;
	}
	if (!IS_ALIGNED(key->offset, sectorsize)) {
	generic_err(root, leaf, slot,
	"unaligned key offset for csum item, have %llu should be aligned to %u",
	key->offset, sectorsize);
	return -EUCLEAN;
	}
	if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) {
	generic_err(root, leaf, slot,
	"unaligned item size for csum item, have %u should be aligned to %u",
	btrfs_item_size_nr(leaf, slot), csumsize);
	return -EUCLEAN;
	}
	return 0;
	}

	/*
	* Common point to switch the item-specific validation.
	*/
	static int check_leaf_item(struct btrfs_root *root,
	struct extent_buffer *leaf,
	struct btrfs_key *key, int slot)
	{
	int ret = 0;

	switch (key->type) {
	case BTRFS_EXTENT_DATA_KEY:
	ret = check_extent_data_item(root, leaf, key, slot);
	break;
	case BTRFS_EXTENT_CSUM_KEY:
	ret = check_csum_item(root, leaf, key, slot);
	break;
	}
	return ret;
	}

	static int check_leaf(struct btrfs_root root, struct extent_buffer leaf,
	bool check_item_data)
	{
	struct btrfs_fs_info *fs_info = root->fs_info;
	/* No valid key type is 0, so all key should be larger than this key */
	struct btrfs_key prev_key = {0, 0, 0};
	struct btrfs_key key;
	u32 nritems = btrfs_header_nritems(leaf);
	int slot;

	/*
	* Extent buffers from a relocation tree have a owner field that
	* corresponds to the subvolume tree they are based on. So just from an
	* extent buffer alone we can not find out what is the id of the
	* corresponding subvolume tree, so we can not figure out if the extent
	* buffer corresponds to the root of the relocation tree or not. So
	* skip this check for relocation trees.
	*/
	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
	struct btrfs_root *check_root;

	key.objectid = btrfs_header_owner(leaf);
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;

	check_root = btrfs_get_fs_root(fs_info, &key, false);
	/*
	* The only reason we also check NULL here is that during
	* open_ctree() some roots has not yet been set up.
	*/
	if (!IS_ERR_OR_NULL(check_root)) {
	struct extent_buffer *eb;

	eb = btrfs_root_node(check_root);
	/* if leaf is the root, then it's fine */
	if (leaf != eb) {
	generic_err(check_root, leaf, 0,
	"invalid nritems, have %u should not be 0 for non-root leaf",
	nritems);
	free_extent_buffer(eb);
	return -EUCLEAN;
	}
	free_extent_buffer(eb);
	}
	return 0;
	}

	if (nritems == 0)
	return 0;

	/*
	* Check the following things to make sure this is a good leaf, and
	* leaf users won't need to bother with similar sanity checks:
	*
	* 1) key ordering
	* 2) item offset and size
	* No overlap, no hole, all inside the leaf.
	* 3) item content
	* If possible, do comprehensive sanity check.
	* NOTE: All checks must only rely on the item data itself.
	*/
	for (slot = 0; slot < nritems; slot++) {
	u32 item_end_expected;
	int ret;

	btrfs_item_key_to_cpu(leaf, &key, slot);

	/* Make sure the keys are in the right order */
	if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) {
	generic_err(root, leaf, slot,
	"bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
	prev_key.objectid, prev_key.type,
	prev_key.offset, key.objectid, key.type,
	key.offset);
	return -EUCLEAN;
	}

	/*
	* Make sure the offset and ends are right, remember that the
	* item data starts at the end of the leaf and grows towards the
	* front.
	*/
	if (slot == 0)
	item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
	else
	item_end_expected = btrfs_item_offset_nr(leaf,
	slot - 1);
	if (btrfs_item_end_nr(leaf, slot) != item_end_expected) {
	generic_err(root, leaf, slot,
	"unexpected item end, have %u expect %u",
	btrfs_item_end_nr(leaf, slot),
	item_end_expected);
	return -EUCLEAN;
	}

	/*
	* Check to make sure that we don't point outside of the leaf,
	* just in case all the items are consistent to each other, but
	* all point outside of the leaf.
	*/
	if (btrfs_item_end_nr(leaf, slot) >
	BTRFS_LEAF_DATA_SIZE(fs_info)) {
	generic_err(root, leaf, slot,
	"slot end outside of leaf, have %u expect range [0, %u]",
	btrfs_item_end_nr(leaf, slot),
	BTRFS_LEAF_DATA_SIZE(fs_info));
	return -EUCLEAN;
	}

	/* Also check if the item pointer overlaps with btrfs item. */
	if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) >
	btrfs_item_ptr_offset(leaf, slot)) {
	generic_err(root, leaf, slot,
	"slot overlaps with its data, item end %lu data start %lu",
	btrfs_item_nr_offset(slot) +
	sizeof(struct btrfs_item),
	btrfs_item_ptr_offset(leaf, slot));
	return -EUCLEAN;
	}

	if (check_item_data) {
	/*
	* Check if the item size and content meet other
	* criteria
	*/
	ret = check_leaf_item(root, leaf, &key, slot);
	if (ret < 0)
	return ret;
	}

	prev_key.objectid = key.objectid;
	prev_key.type = key.type;
	prev_key.offset = key.offset;
	}

	return 0;
	}

	int btrfs_check_leaf_full(struct btrfs_root root, struct extent_buffer leaf)
	{
	return check_leaf(root, leaf, true);
	}

	int btrfs_check_leaf_relaxed(struct btrfs_root *root,
	struct extent_buffer *leaf)
	{
	return check_leaf(root, leaf, false);
	}

	int btrfs_check_node(struct btrfs_root root, struct extent_buffer node)
	{
	unsigned long nr = btrfs_header_nritems(node);
	struct btrfs_key key, next_key;
	int slot;
	u64 bytenr;
	int ret = 0;

	if (nr == 0 \|\| nr > BTRFS_NODEPTRS_PER_BLOCK(root->fs_info)) {
	btrfs_crit(root->fs_info,
	"corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
	root->objectid, node->start,
	nr == 0 ? "small" : "large", nr,
	BTRFS_NODEPTRS_PER_BLOCK(root->fs_info));
	return -EUCLEAN;
	}

	for (slot = 0; slot < nr - 1; slot++) {
	bytenr = btrfs_node_blockptr(node, slot);
	btrfs_node_key_to_cpu(node, &key, slot);
	btrfs_node_key_to_cpu(node, &next_key, slot + 1);

	if (!bytenr) {
	generic_err(root, node, slot,
	"invalid NULL node pointer");
	ret = -EUCLEAN;
	goto out;
	}
	if (!IS_ALIGNED(bytenr, root->fs_info->sectorsize)) {
	generic_err(root, node, slot,
	"unaligned pointer, have %llu should be aligned to %u",
	bytenr, root->fs_info->sectorsize);
	ret = -EUCLEAN;
	goto out;
	}

	if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
	generic_err(root, node, slot,
	"bad key order, current (%llu %u %llu) next (%llu %u %llu)",
	key.objectid, key.type, key.offset,
	next_key.objectid, next_key.type,
	next_key.offset);
	ret = -EUCLEAN;
	goto out;
	}
	}
	out:
	return ret;
	}