[dm-devel] [PATCH] multipathd: fix no checking persistent reservation registration

[lixiaokeng]

If one multipath device has two paths, the first is down (network
failure) and the second is up, then we register a prkey to the
device. The first path will register successfully but the second
won't. Then fix the network. The uev_update_path will race with
check_path. If uev_update_path -> pathinfo is called before
check_path, the state of the first path will be set PATH_UP
without checking persistent reservation registration.

Here we add checking in uev_update_path.

Signed-off-by: Lixiaokeng <lixiaokeng at huawei.com>
---
 multipathd/main.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/multipathd/main.c b/multipathd/main.c
index 2251e02c..0948bf81 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -1316,6 +1316,7 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
 	struct path * pp;
 	struct config *conf;
 	int needs_reinit = 0;
+	int oldstate;

 	switch ((rc = change_foreign(uev->udev))) {
 	case FOREIGN_OK:
@@ -1366,9 +1367,22 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
 			pp->udev = udev_device_ref(uev->udev);
 			conf = get_multipath_config();
 			pthread_cleanup_push(put_multipath_config, conf);
+			oldstate = pp->state;
+
 			if (pathinfo(pp, conf, DI_SYSFS|DI_NOIO) != PATHINFO_OK)
 				condlog(1, "%s: pathinfo failed after change uevent",
 					uev->kernel);
+
+			if (pp->state != oldstate && (pp->state == PATH_UP || pp->state == PATH_GHOST)) {
+				if (pp->mpp && pp->mpp->prflag) {
+					/*
+					 * Check Persistent Reservation.
+					 */
+					condlog(2, "%s: checking persistent reservation "
+						"registration when update path", pp->dev);
+					mpath_pr_event_handle(pp);
+				}
+			}
 			pthread_cleanup_pop(1);
 		}

--