diff options
author | Qu Wenruo <quwenruo@cn.fujitsu.com> | 2014-10-06 14:31:21 +0800 |
---|---|---|
committer | David Sterba <dsterba@suse.cz> | 2014-10-10 10:38:38 +0200 |
commit | 0cf497719cf8d2c6f7967a386a7b54b0119fd1b4 (patch) | |
tree | eb0d61b948311b9be1ee51e1e481fb0ae0e93a81 | |
parent | 935457f16446012841f8da5a5c9804063d76b366 (diff) |
btrfs-progs: Check the consistence between the parent node and child node/leaf.
When btrfs-progs walk down the tree, it does not check whether the child
node/leaf is valid.
In fact, there is some corrupted image whose csum is all valid but
parent node points to a invalid leaf.
In my case, the parent node in fs tree point to a invalid leaf(gen 11),
whose generation(15) and first key(EXTENT_TREE ROOT_ITEM 0) is
completely invalid, and will cause BUG_ON in process_inode_item().
Unfortunately, we are unable to fix when it happens.
So we can only output meaningful error message and avoid the insane
node/leaf, which is still much better than the original BUG_ON().
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
-rw-r--r-- | cmds-check.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/cmds-check.c b/cmds-check.c index 2aab34b1..a1d5a557 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -1335,6 +1335,56 @@ static void reada_walk_down(struct btrfs_root *root, } } +/* + * Check the child node/leaf by the following condition: + * 1. the first item key of the node/leaf should be the same with the one + * in parent. + * 2. block in parent node should match the child node/leaf. + * 3. generation of parent node and child's header should be consistent. + * + * Or the child node/leaf pointed by the key in parent is not valid. + * + * We hope to check leaf owner too, but since subvol may share leaves, + * which makes leaf owner check not so strong, key check should be + * sufficient enough for that case. + */ +static int check_child_node(struct btrfs_root *root, + struct extent_buffer *parent, int slot, + struct extent_buffer *child) +{ + struct btrfs_key parent_key; + struct btrfs_key child_key; + int ret = 0; + + btrfs_node_key_to_cpu(parent, &parent_key, slot); + if (btrfs_header_level(child) == 0) + btrfs_item_key_to_cpu(child, &child_key, 0); + else + btrfs_node_key_to_cpu(child, &child_key, 0); + + if (memcmp(&parent_key, &child_key, sizeof(parent_key))) { + ret = -EINVAL; + fprintf(stderr, + "Wrong key of child node/leaf, wanted: (%llu, %u, %llu), have: (%llu, %u, %llu)\n", + parent_key.objectid, parent_key.type, parent_key.offset, + child_key.objectid, child_key.type, child_key.offset); + } + if (btrfs_header_bytenr(child) != btrfs_node_blockptr(parent, slot)) { + ret = -EINVAL; + fprintf(stderr, "Wrong block of child node/leaf, wanted: %llu, have: %llu\n", + btrfs_node_blockptr(parent, slot), + btrfs_header_bytenr(child)); + } + if (btrfs_node_ptr_generation(parent, slot) != + btrfs_header_generation(child)) { + ret = -EINVAL; + fprintf(stderr, "Wrong generation of child node/leaf, wanted: %llu, have: %llu\n", + btrfs_header_generation(child), + btrfs_node_ptr_generation(parent, slot)); + } + return ret; +} + static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int *level) { @@ -1410,6 +1460,11 @@ static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path, } } + ret = check_child_node(root, cur, path->slots[*level], next); + if (ret) { + err = ret; + goto out; + } *level = *level - 1; free_extent_buffer(path->nodes[*level]); path->nodes[*level] = next; |