aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorLiu Bo <bo.li.liu@oracle.com>2016-08-23 15:22:58 -0700
committerChris Mason <clm@fb.com>2016-08-25 03:58:31 -0700
commit1ba98d086fe3a14d6a31f2f66dbab70c45d00f63 (patch)
treec521349d7730ec47b60fe78a63822123c0fcf87d
parent053ab70f0604224c7893b43f9d9d5efa283580d6 (diff)
downloadlinux-yocto-4.8-1ba98d086fe3a14d6a31f2f66dbab70c45d00f63.tar.gz
linux-yocto-4.8-1ba98d086fe3a14d6a31f2f66dbab70c45d00f63.tar.bz2
linux-yocto-4.8-1ba98d086fe3a14d6a31f2f66dbab70c45d00f63.zip
Btrfs: detect corruption when non-root leaf has zero item
Right now we treat leaf which has zero item as a valid one because we could have an empty tree, that is, a root that is also a leaf without any item, however, in the same case but when the leaf is not a root, we can end up with hitting the BUG_ON(1) in btrfs_extend_item() called by setup_inline_extent_backref(). This makes us check the situation as a corruption if leaf is not its own root. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
-rw-r--r--fs/btrfs/disk-io.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 474209f50844..70e76ad11fbf 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -560,8 +560,29 @@ static noinline int check_leaf(struct btrfs_root *root,
u32 nritems = btrfs_header_nritems(leaf);
int slot;
- if (nritems == 0)
+ if (nritems == 0) {
+ 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(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)) {
+ /* if leaf is the root, then it's fine */
+ if (leaf->start !=
+ btrfs_root_bytenr(&check_root->root_item)) {
+ CORRUPT("non-root leaf's nritems is 0",
+ leaf, root, 0);
+ return -EIO;
+ }
+ }
return 0;
+ }
/* Check the 0 item */
if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=