btrfs-progs: Enhance tree block check by checking empty leaf or node

For btrfs, it's possible to have empty leaf, but empty node is not
possible.

Add check for empty node for tree blocks.

Suggested-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/disk-io.c b/disk-io.c
index 86abdeb..b4f185f 100644 (file)
--- a/disk-io.c
+++ b/disk-io.c
@@ -67,6 +67,11 @@ static int check_tree_block(struct btrfs_fs_info *fs_info,
                                                    nodesize))
                return BTRFS_BAD_NRITEMS;
 
+       /* Only leaf can be empty */
+       if (btrfs_header_nritems(buf) == 0 &&
+           btrfs_header_level(buf) != 0)
+               return BTRFS_BAD_NRITEMS;
+
        fs_devices = fs_info->fs_devices;
        while (fs_devices) {
                if (fs_info->ignore_fsid_mismatch ||