ceph: add F_SYNC file flag to force sync (non-O_DIRECT) io

This allows us to force IO through the sync path which you normally only
get when multiple clients are reading/writing to the same file or by
mounting with -o sync.  Among other things, this lets test programs verify
correctness with a single mount.

Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 8febe6fce2b1..cdb17d36755c 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -543,6 +543,8 @@ extern void ceph_reservation_status(struct ceph_fs_client *client,
 /*
  * we keep buffered readdir results attached to file->private_data
  */
+#define CEPH_F_SYNC     1
+
 struct ceph_file_info {
         short fmode;     /* initialized on open */
         short flags;     /* CEPH_F_* */