[multipathd] remove pthread_cancel logic to stop waiter a thread

Rely only on the ioctl interruption through a signal, proposed by
Ben. Note we never actually used this code before, my bad.

diff --git a/multipathd/main.c b/multipathd/main.c
index aaa9180..e56f672 100644 (file)
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -98,6 +98,29 @@ alloc_waiter (void)
 }
 
 static void
+free_waiter (void * data)
+{
+       struct event_thread * wp = (struct event_thread *)data;
+
+       if (wp->dmt)
+               dm_task_destroy(wp->dmt);
+       FREE(wp);
+}
+
+static void
+stop_waiter_thread (struct multipath * mpp, struct vectors * vecs)
+{
+       struct event_thread * wp = (struct event_thread *)mpp->waiter;
+       pthread_t thread = wp->thread;
+
+       if (!wp)
+               return;
+
+       condlog(2, "%s: stop event checker thread", wp->mapname);
+       pthread_kill(thread, SIGHUP);
+}
+
+static void
 cleanup_lock (void * data)
 {
        pthread_mutex_unlock((pthread_mutex_t *)data);
@@ -310,11 +333,49 @@ extract_hwe_from_path(struct multipath * mpp)
        return pp->hwe;
 }
 
-static int
-setup_multipath (struct vectors * vecs, struct multipath * mpp)
+static void
+remove_map (struct multipath * mpp, struct vectors * vecs)
 {
        int i;
 
+       stop_waiter_thread(mpp, vecs);
+
+       /*
+        * clear references to this map
+        */
+       orphan_paths(vecs, mpp);
+
+       /*
+        * purge the multipath vector
+        */
+       i = find_slot(vecs->mpvec, (void *)mpp);
+       vector_del_slot(vecs->mpvec, i);
+
+       /*
+        * final free
+        */
+       free_multipath(mpp, KEEP_PATHS);
+       mpp = NULL;
+}
+
+static void
+remove_maps (struct vectors * vecs)
+{
+       int i;
+       struct multipath * mpp;
+
+       vector_foreach_slot (vecs->mpvec, mpp, i) {
+               remove_map(mpp, vecs);
+               i--;
+       }
+
+       vector_free(vecs->mpvec);
+       vecs->mpvec = NULL;
+}
+
+static int
+setup_multipath (struct vectors * vecs, struct multipath * mpp)
+{
        set_multipath_wwid(mpp);
        mpp->mpe = find_mpe(mpp->wwid);
        condlog(4, "discovered map %s", mpp->alias);
@@ -329,13 +390,7 @@ setup_multipath (struct vectors * vecs, struct multipath * mpp)
 
        return 0;
 out:
-       /*
-        * purge the multipath vector
-        */
-       if ((i = find_slot(vecs->mpvec, (void *)mpp)) != -1)
-               vector_del_slot(vecs->mpvec, i);
-
-       free_multipath(mpp, KEEP_PATHS);
+       remove_map(mpp, vecs);
        condlog(0, "failed to setup multipath");
        return 1;
 }
@@ -431,16 +486,6 @@ out:
        return r;
 }
 
-static void
-free_waiter (void * data)
-{
-       struct event_thread * wp = (struct event_thread *)data;
-
-       if (wp->dmt)
-               dm_task_destroy(wp->dmt);
-       FREE(wp);
-}
-
 static sigset_t unblock_sighup(void)
 {
        sigset_t set, old;
@@ -480,14 +525,25 @@ waiteventloop (struct event_thread * waiter)
        }
 
        dm_task_no_open_count(waiter->dmt);
-
+       
+       /* accept wait interruption */
        set = unblock_sighup();
-       dm_task_run(waiter->dmt);
+
+       /* interruption spits messages */
+       dm_shut_log();
+
+       /* wait */
+       r = dm_task_run(waiter->dmt);
+
+       /* wait is over : event or interrupt */
        pthread_sigmask(SIG_SETMASK, &set, NULL);
-       pthread_testcancel();
+       //dm_restore_log();
+
+       if (!r) /* wait interrupted by signal */
+               return -1;
+
        dm_task_destroy(waiter->dmt);
        waiter->dmt = NULL;
-
        waiter->event_nr++;
 
        /*
@@ -543,9 +599,7 @@ waitevent (void * et)
                if (r < 0)
                        break;
 
-               pthread_testcancel();
                sleep(r);
-               pthread_testcancel();
        }
 
        pthread_cleanup_pop(1);
@@ -553,27 +607,6 @@ waitevent (void * et)
 }
 
 static int
-stop_waiter_thread (struct multipath * mpp, struct vectors * vecs)
-{
-       struct event_thread * wp = (struct event_thread *)mpp->waiter;
-       pthread_t thread = wp->thread;
-       int r;
-
-       if (!wp)
-               return 1;
-
-       condlog(2, "%s: stop event checker thread", wp->mapname);
-
-       if ((r = pthread_cancel(thread)))
-               return r;
-
-       condlog(2, "%s: couldn't stop event checker thread gracefully, kill",
-               wp->mapname);
-       pthread_kill(thread, SIGHUP);
-       return 0;
-}
-
-static int
 start_waiter_thread (struct multipath * mpp, struct vectors * vecs)
 {
        pthread_attr_t attr;
@@ -612,60 +645,10 @@ out:
        return 1;
 }
 
-static void
-remove_map (struct multipath * mpp, struct vectors * vecs)
-{
-       int i;
-
-       /*
-        * stop the DM event waiter thread
-        */
-       if (stop_waiter_thread(mpp, vecs)) {
-               condlog(0, "%s: error canceling waiter thread", mpp->alias);
-               /*
-                * warrior mode
-                */
-               free_waiter(mpp->waiter);
-               mpp->waiter = NULL;
-       }
-
-       /*
-        * clear references to this map
-        */
-       orphan_paths(vecs, mpp);
-
-       /*
-        * purge the multipath vector
-        */
-       i = find_slot(vecs->mpvec, (void *)mpp);
-       vector_del_slot(vecs->mpvec, i);
-
-       /*
-        * final free
-        */
-       free_multipath(mpp, KEEP_PATHS);
-       mpp = NULL;
-}
-
-static void
-remove_maps (struct vectors * vecs)
-{
-       int i;
-       struct multipath * mpp;
-
-       vector_foreach_slot (vecs->mpvec, mpp, i) {
-               remove_map(mpp, vecs);
-               i--;
-       }
-
-       vector_free(vecs->mpvec);
-       vecs->mpvec = NULL;
-}
-
 int
 uev_add_map (char * devname, struct vectors * vecs)
 {
-       int major, minor, i;
+       int major, minor;
        char dev_t[BLK_DEV_SIZE];
        char * alias;
        struct multipath * mpp;
@@ -724,13 +707,7 @@ uev_add_map (char * devname, struct vectors * vecs)
        return 0;
 out:
        condlog(2, "%s: add devmap failed", mpp->alias);
-       /*
-        * purge the multipath vector
-        */
-       if ((i = find_slot(vecs->mpvec, (void *)mpp)) != -1)
-               vector_del_slot(vecs->mpvec, i);
-
-       free_multipath(mpp, KEEP_PATHS);
+       remove_map(mpp, vecs);
        return 1;
 }
 
@@ -1050,10 +1027,9 @@ out:
 static void *
 ueventloop (void * ap)
 {
-       if (uevent_listen(&uev_trigger, ap)) {
+       if (uevent_listen(&uev_trigger, ap))
                fprintf(stderr, "error starting uevent listener");
-               exit;
-       }
+               
        return NULL;
 }