From: Mike Snitzer <snitzer@redhat.com>
Date: Tue, 8 Feb 2011 18:49:06 -0500
Subject: [md] dm-mpath: skip activate_path for failed paths
Message-id: <1297190949-29149-7-git-send-email-snitzer@redhat.com>
Patchwork-id: 33171
O-Subject: [RHEL5.7 PATCH 5/8] dm mpath: skip activate_path for failed paths
Bugzilla: 673058
RH-Acked-by: Alasdair G Kergon <agk@redhat.com>

BZ 673058

Upstream commit f7b934c8127deebf4eb56fbe4a4ae0da16b6dbcd
Author: Moger, Babu <Babu.Moger@lsi.com>
Date:   Sat Mar 6 02:29:49 2010 +0000

    dm mpath: skip activate_path for failed paths

    This patch adds two minor fixes while processing device mapper path activation.

    Skip failed paths while calling activate_path.  If the path is already failed
    then activate_path will fail for sure. We don't have to call in that case. In
    some case this might cause prolonged retries unnecessarily.

    Change the misleading message if the path being activated fails with SCSI_DH_NOSYS.

    Signed-off-by: Babu Moger <babu.moger@lsi.com>
    Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index c49bc0e..4de9a33 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -449,6 +449,9 @@ static void process_queued_ios(void *data)
 			init_required = 1;
 		} else {
 			list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) {
+				/* Skip failed paths */
+				if (!tmp->path.is_active)
+					continue;
 				if (queue_delayed_work(kmpath_handlerd,
 				    &tmp->activate_path, m->pg_init_delay ?
 				    m->pg_init_delay_secs * HZ : 0))
@@ -1199,8 +1202,8 @@ static void pg_init_done(void *data, int errors)
 			errors = 0;
 			break;
 		}
-		DMERR("Cannot failover device because scsi_dh_%s was not "
-		      "loaded.", m->hw_handler_name);
+		DMERR("Could not failover the device: Handler scsi_dh_%s "
+		      "Error %d.", m->hw_handler_name, errors);
 		/*
 		 * Fail path for now, so we do not ping pong
 		 */