Btrfs: Update find free objectid function for orphan cleanup code

Orphan items use BTRFS_ORPHAN_OBJECTID (-5UUL) as key objectid. This
affects the find free objectid functions, inode objectid can easily
overflow after orphan file cleanup.

---

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 754c738ec2e8..2ed6918f32e5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -82,9 +82,10 @@ struct btrfs_ordered_sum;
 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
 
 /*
- * All files have objectids higher than this.
+ * All files have objectids in this range.
  */
 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
+#define BTRFS_LAST_FREE_OBJECTID -256ULL
 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL