fcntl() locking does not pair at all with dlm locking. So both ocfs2 and gfs2 use a special scheme just for this lock. Both use the ordered messaging provided by the corosync cluster engine. This lock is fully synchronised and thus is not as performant as it can be. (Both cman and pacemaker use cce.)
But that's ok because fcntl()'s locking semantics is not what you think it is. The lock is almost useless in this day and age. The only use is supporting legacy apps. For more refer to Jeremy Allison's overview of this user lock. http://www.samba.org/samba/news/articles/low_point/tale_two_stds_os2.html Given that and considering most apps allow users to choose between fcntl() and flock(), we've decided for now to just support the latter with o2cb. flock() pairs well with dlm locking. On 01/18/2011 10:22 AM, Dan Warner wrote:
OK thanks for the clarification. Is the support of fcntl() locking within o2cb, on the wishlist of features to be implemented at a future date? Is it even a priority to do? Thanks, Dan On 18 January 2011 18:00, Sunil Mushran <sunil.mush...@oracle.com <mailto:sunil.mush...@oracle.com>> wrote: ping_long tests the fcntl() user locks. ocfs2 supports clustered fcntl() locking with cman and pacemaker cluster stacks. Not with o2cb. ocfs2 supports clustered flock() with all stacks. o2cb, cman and pacemaker. _______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-users
_______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-users
