1 files changed, 4 insertions, 0 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f870aefc59dd..a3798a3aa0d2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7115,6 +7115,10 @@ static long btrfs_fallocate(struct inode *inode, int mode,
         alloc_start = offset & ~mask;
         alloc_end =  (offset + len + mask) & ~mask;
 
+        /* We only support the FALLOC_FL_KEEP_SIZE mode */
+        if (mode && (mode != FALLOC_FL_KEEP_SIZE))
+                return -EOPNOTSUPP;
+
         /*
          * wait for ordered IO before we have any locks.  We'll loop again
          * below with the locks held.