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btrfs: tree-checker: Try to detect missing INODE_ITEM

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For the following items, key->objectid is inode number:
- DIR_ITEM
- DIR_INDEX
- XATTR_ITEM
- EXTENT_DATA
- INODE_REF

So in the subvolume tree, such items must have its previous item share the
same objectid, e.g.:

 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 INODE_ITEM 0)
 (258 INODE_REF 0)
 (258 XATTR_ITEM 0)
 (258 EXTENT_DATA 0)

But if we have the following sequence, then there is definitely
something wrong, normally some INODE_ITEM is missing, like:

 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 XATTR_ITEM 0)  <<< objecitd suddenly changed to 258
 (258 EXTENT_DATA 0)

So just by checking the previous key for above inode based key types, we
can detect a missing inode item.

For INODE_REF key type, the check will be added along with INODE_REF
checker.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2019-08-26 15:40:38 +08:00 committed by David Sterba
parent b9fae2ebee
commit c18679ebd8
1 changed files with 25 additions and 2 deletions
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27
fs/btrfs/tree-checker.c
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@ -141,6 +141,20 @@ static int check_extent_data_item(struct extent_buffer *leaf,
return -EUCLEAN;
}
/*
* Previous key must have the same key->objectid (ino).
* It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
* But if objectids mismatch, it means we have a missing
* INODE_ITEM.
*/
if (slot > 0 && is_fstree(btrfs_header_owner(leaf)) &&
prev_key->objectid != key->objectid) {
file_extent_err(leaf, slot,
"invalid previous key objectid, have %llu expect %llu",
prev_key->objectid, key->objectid);
return -EUCLEAN;
}
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
@ -299,13 +313,22 @@ static void dir_item_err(const struct extent_buffer *eb, int slot,
}
static int check_dir_item(struct extent_buffer *leaf,
struct btrfs_key *key, int slot)
struct btrfs_key *key, struct btrfs_key *prev_key,
int slot)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct btrfs_dir_item *di;
u32 item_size = btrfs_item_size_nr(leaf, slot);
u32 cur = 0;
/* Same check as in check_extent_data_item() */
if (slot > 0 && is_fstree(btrfs_header_owner(leaf)) &&
prev_key->objectid != key->objectid) {
dir_item_err(leaf, slot,
"invalid previous key objectid, have %llu expect %llu",
prev_key->objectid, key->objectid);
return -EUCLEAN;
}
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
while (cur < item_size) {
u32 name_len;
@ -1244,7 +1267,7 @@ static int check_leaf_item(struct extent_buffer *leaf,
case BTRFS_DIR_ITEM_KEY:
case BTRFS_DIR_INDEX_KEY:
case BTRFS_XATTR_ITEM_KEY:
ret = check_dir_item(leaf, key, slot);
ret = check_dir_item(leaf, key, prev_key, slot);
break;
case BTRFS_BLOCK_GROUP_ITEM_KEY:
ret = check_block_group_item(leaf, key, slot);