Commit 0785a9aa authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: tree-checker: Add EXTENT_DATA_REF check 



EXTENT_DATA_REF is a little like DIR_ITEM which contains hash in its
key->offset.

This patch will check the following contents:
- Key->objectid
  Basic alignment check.

- Hash
  Hash of each extent_data_ref item must match key->offset.

- Offset
  Basic alignment check.

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent e2406a6f

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -2447,6 +2447,7 @@ enum btrfs_inline_ref_type { 
int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,

				     struct btrfs_extent_inline_ref *iref,

				     enum btrfs_inline_ref_type is_data);

u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset);



u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes);

fs/btrfs/extent-tree.c

+1 −1
Original line number Diff line number Diff line
@@ -438,7 +438,7 @@ int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb, 
	return BTRFS_REF_TYPE_INVALID;

}



static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)

u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)

{

	u32 high_crc = ~(u32)0;

	u32 low_crc = ~(u32)0;

fs/btrfs/tree-checker.c

+48 −0
Original line number Diff line number Diff line
@@ -1187,6 +1187,51 @@ static int check_simple_keyed_refs(struct extent_buffer *leaf, 
	return 0;

}



static int check_extent_data_ref(struct extent_buffer *leaf,

				 struct btrfs_key *key, int slot)

{

	struct btrfs_extent_data_ref *dref;

	unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);

	const unsigned long end = ptr + btrfs_item_size_nr(leaf, slot);



	if (btrfs_item_size_nr(leaf, slot) % sizeof(*dref) != 0) {

		generic_err(leaf, slot,

	"invalid item size, have %u expect aligned to %zu for key type %u",

			    btrfs_item_size_nr(leaf, slot),

			    sizeof(*dref), key->type);

	}

	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {

		generic_err(leaf, slot,

"invalid key objectid for shared block ref, have %llu expect aligned to %u",

			    key->objectid, leaf->fs_info->sectorsize);

		return -EUCLEAN;

	}

	for (; ptr < end; ptr += sizeof(*dref)) {

		u64 root_objectid;

		u64 owner;

		u64 offset;

		u64 hash;



		dref = (struct btrfs_extent_data_ref *)ptr;

		root_objectid = btrfs_extent_data_ref_root(leaf, dref);

		owner = btrfs_extent_data_ref_objectid(leaf, dref);

		offset = btrfs_extent_data_ref_offset(leaf, dref);

		hash = hash_extent_data_ref(root_objectid, owner, offset);

		if (hash != key->offset) {

			extent_err(leaf, slot,

	"invalid extent data ref hash, item has 0x%016llx key has 0x%016llx",

				   hash, key->offset);

			return -EUCLEAN;

		}

		if (!IS_ALIGNED(offset, leaf->fs_info->sectorsize)) {

			extent_err(leaf, slot,

	"invalid extent data backref offset, have %llu expect aligned to %u",

				   offset, leaf->fs_info->sectorsize);

		}

	}

	return 0;

}



/*

 * Common point to switch the item-specific validation.

 */
@@ -1234,6 +1279,9 @@ static int check_leaf_item(struct extent_buffer *leaf, 
	case BTRFS_SHARED_BLOCK_REF_KEY:

		ret = check_simple_keyed_refs(leaf, key, slot);

		break;

	case BTRFS_EXTENT_DATA_REF_KEY:

		ret = check_extent_data_ref(leaf, key, slot);

		break;

	}

	return ret;

}

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