From c36258b5925e6cf6bf72904635100593573bfcff Mon Sep 17 00:00:00 2001 From: David Teigland Date: Thu, 27 Sep 2007 15:53:38 -0500 Subject: [DLM] block dlm_recv in recovery transition Introduce a per-lockspace rwsem that's held in read mode by dlm_recv threads while working in the dlm. This allows dlm_recv activity to be suspended when the lockspace transitions to, from and between recovery cycles. The specific bug prompting this change is one where an in-progress recovery cycle is aborted by a new recovery cycle. While dlm_recv was processing a recovery message, the recovery cycle was aborted and dlm_recoverd began cleaning up. dlm_recv decremented recover_locks_count on an rsb after dlm_recoverd had reset it to zero. This is fixed by suspending dlm_recv (taking write lock on the rwsem) before aborting the current recovery. The transitions to/from normal and recovery modes are simplified by using this new ability to block dlm_recv. The switch from normal to recovery mode means dlm_recv goes from processing locking messages, to saving them for later, and vice versa. Races are avoided by blocking dlm_recv when setting the flag that switches between modes. Signed-off-by: David Teigland Signed-off-by: Steven Whitehouse --- fs/dlm/lockspace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/dlm/lockspace.c') diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index 1dc72105ab1..628eaa669e6 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -519,6 +519,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, ls->ls_recover_seq = 0; ls->ls_recover_args = NULL; init_rwsem(&ls->ls_in_recovery); + init_rwsem(&ls->ls_recv_active); INIT_LIST_HEAD(&ls->ls_requestqueue); mutex_init(&ls->ls_requestqueue_mutex); mutex_init(&ls->ls_clear_proc_locks); -- cgit v1.2.3