[DLM] add lock timeouts and warnings [2/6]

New features: lock timeouts and time warnings.  If the DLM_LKF_TIMEOUT
flag is set, then the request/conversion will be canceled after waiting
the specified number of centiseconds (specified per lock).  This feature
is only available for locks requested through libdlm (can be enabled for
kernel dlm users if there's a use for it.)

If the new DLM_LSFL_TIMEWARN flag is set when creating the lockspace, then
a warning message will be sent to userspace (using genetlink) after a
request/conversion has been waiting for a given number of centiseconds
(configurable per node).  The time warnings will be used in the future
to do deadlock detection in userspace.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 414a108..339a204 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -237,6 +237,7 @@ static int dlm_scand(void *data)
 		list_for_each_entry(ls, &lslist, ls_list) {
 			if (dlm_lock_recovery_try(ls)) {
 				dlm_scan_rsbs(ls);
+				dlm_scan_timeout(ls);
 				dlm_unlock_recovery(ls);
 			}
 		}
@@ -421,11 +422,16 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
 		goto out;
 	memcpy(ls->ls_name, name, namelen);
 	ls->ls_namelen = namelen;
-	ls->ls_exflags = flags;
 	ls->ls_lvblen = lvblen;
 	ls->ls_count = 0;
 	ls->ls_flags = 0;
 
+	/* ls_exflags are forced to match among nodes, and we don't
+	   need to require all nodes to have TIMEWARN active */
+	if (flags & DLM_LSFL_TIMEWARN)
+		set_bit(LSFL_TIMEWARN, &ls->ls_flags);
+	ls->ls_exflags = (flags & ~DLM_LSFL_TIMEWARN);
+
 	size = dlm_config.ci_rsbtbl_size;
 	ls->ls_rsbtbl_size = size;
 
@@ -465,6 +471,8 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
 	mutex_init(&ls->ls_waiters_mutex);
 	INIT_LIST_HEAD(&ls->ls_orphans);
 	mutex_init(&ls->ls_orphans_mutex);
+	INIT_LIST_HEAD(&ls->ls_timeout);
+	mutex_init(&ls->ls_timeout_mutex);
 
 	INIT_LIST_HEAD(&ls->ls_nodes);
 	INIT_LIST_HEAD(&ls->ls_nodes_gone);