[PATCH 1/2] ocfs2: add flock lock type

This adds a new dlmglue lock type which is intended to back flock()
requests.

Since these locks are driven from userspace, usage rules are much more
liberal than the typical Ocfs2 internal cluster lock. As a result, we can't
make use of most dlmglue features - lock caching and lock level
optimizations in particular. Additionally, userspace is free to deadlock
itself, so we have to deal with that in the same way as the rest of the
kernel - by allowing a signal to abort a lock request.

In order to keep ocfs2_cluster_lock() complexity down, ocfs2_file_lock()
does it's own dlm coordination. We still use the same helper functions
though, so duplicated code is kept to a minimum.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index d12bd7036da7..63c131e1cc77 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -101,6 +101,7 @@ enum ocfs2_unlock_action {
                                                * about to be
                                                * dropped. */
 #define OCFS2_LOCK_QUEUED        (0x00000100) /* queued for downconvert */
+#define OCFS2_LOCK_NOCACHE       (0x00000200) /* don't use a holder count */
 
 struct ocfs2_lock_res_ops;