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| author | Liu Bo <bo.li.liu@oracle.com> | 2016-08-23 22:22:58 (GMT) |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2016-08-25 10:58:31 (GMT) |
| commit | 1ba98d086fe3a14d6a31f2f66dbab70c45d00f63 (patch) | |
| tree | c521349d7730ec47b60fe78a63822123c0fcf87d /fs | |
| parent | 053ab70f0604224c7893b43f9d9d5efa283580d6 (diff) | |
| download | linux-1ba98d086fe3a14d6a31f2f66dbab70c45d00f63.tar.xz | |
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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/disk-io.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 474209f..70e76ad 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) != |