btrfs: tree-checker: Refactor root key check into separate function

ROOT_ITEM key check itself is not as simple as single line check, and
will be reused for both ROOT_ITEM and DIR_ITEM/DIR_INDEX location key
check, so refactor such check into check_root_key().

Also since we are here, fix a comment error about ROOT_ITEM offset,
which is transid of snapshot creation, not some "older kernel behavior".

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 2019-12-09 18:54:34 +08:00 committed by David Sterba
parent c23c77b097
commit 57a0e67491

View File

@ -428,6 +428,49 @@ static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key,
return 0;
}
static int check_root_key(struct extent_buffer *leaf, struct btrfs_key *key,
int slot)
{
struct btrfs_key item_key;
bool is_root_item;
btrfs_item_key_to_cpu(leaf, &item_key, slot);
is_root_item = (item_key.type == BTRFS_ROOT_ITEM_KEY);
/* No such tree id */
if (key->objectid == 0) {
if (is_root_item)
generic_err(leaf, slot, "invalid root id 0");
else
dir_item_err(leaf, slot,
"invalid location key root id 0");
return -EUCLEAN;
}
/* DIR_ITEM/INDEX/INODE_REF is not allowed to point to non-fs trees */
if (!is_fstree(key->objectid) && !is_root_item) {
dir_item_err(leaf, slot,
"invalid location key objectid, have %llu expect [%llu, %llu]",
key->objectid, BTRFS_FIRST_FREE_OBJECTID,
BTRFS_LAST_FREE_OBJECTID);
return -EUCLEAN;
}
/*
* ROOT_ITEM with non-zero offset means this is a snapshot, created at
* @offset transid.
* Furthermore, for location key in DIR_ITEM, its offset is always -1.
*
* So here we only check offset for reloc tree whose key->offset must
* be a valid tree.
*/
if (key->objectid == BTRFS_TREE_RELOC_OBJECTID && key->offset == 0) {
generic_err(leaf, slot, "invalid root id 0 for reloc tree");
return -EUCLEAN;
}
return 0;
}
static int check_dir_item(struct extent_buffer *leaf,
struct btrfs_key *key, struct btrfs_key *prev_key,
int slot)
@ -978,22 +1021,11 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
struct btrfs_root_item ri;
const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY |
BTRFS_ROOT_SUBVOL_DEAD;
int ret;
/* No such tree id */
if (key->objectid == 0) {
generic_err(leaf, slot, "invalid root id 0");
return -EUCLEAN;
}
/*
* Some older kernel may create ROOT_ITEM with non-zero offset, so here
* we only check offset for reloc tree whose key->offset must be a
* valid tree.
*/
if (key->objectid == BTRFS_TREE_RELOC_OBJECTID && key->offset == 0) {
generic_err(leaf, slot, "invalid root id 0 for reloc tree");
return -EUCLEAN;
}
ret = check_root_key(leaf, key, slot);
if (ret < 0)
return ret;
if (btrfs_item_size_nr(leaf, slot) != sizeof(ri)) {
generic_err(leaf, slot,