tree 4705326641f39fdb1b97c925b55dae3c4634d5e0
parent 2fbe8d1ebe004425b4f7b8bba345623d2280be82
author Mark Fasheh <mark.fasheh@oracle.com> 1198197790 -0800
committer Mark Fasheh <mark.fasheh@oracle.com> 1201302343 -0800

[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>