gfs2: Don't support fallocate on jdata files

We cannot provide an efficient implementation due to the headers
on the data blocks, so there doesn't seem much point in having it.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/file.c

@@ -917,7 +917,7 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t le
 	struct gfs2_holder gh;
 	int ret;
 
-	if (mode & ~FALLOC_FL_KEEP_SIZE)
+	if ((mode & ~FALLOC_FL_KEEP_SIZE) || gfs2_is_jdata(ip))
 		return -EOPNOTSUPP;
 
 	mutex_lock(&inode->i_mutex);