From 7057f25d13b7b11ae683c77cb51796d835c516bd Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Tue, 4 Mar 2008 14:29:35 -0800
Subject: [PATCH] --- yaml --- r: 86847 b: refs/heads/master c:
 1c830532f6b44d10a1743ccd00e990c6b83396f5 h: refs/heads/master i:   86845:
 3568750f0445a37321e511e889732b2979fbc7eb   86843:
 f6c76bdb199299cca8a47f79b70fd27a2d47ca60   86839:
 5541b3e355b80a8e62369e3e354840fea01d2341   86831:
 18488bc07fd4a1e1d8c164b263f93a259bbe3040   86815:
 d278b32e8aa7d05a4d861330ad709e8c2df00dda   86783:
 d60ca20516b72df57f943fbad6f44eff3ad28c04 v: v3

---
 [refs]                    |  2 +-
 trunk/drivers/md/raid1.c  | 11 +++++++++--
 trunk/drivers/md/raid10.c | 11 +++++++++--
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 4a27c0c79ab4..870eb98176a3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8ed3a19563b6c05b7625649b1769ddb063d53253
+refs/heads/master: 1c830532f6b44d10a1743ccd00e990c6b83396f5
diff --git a/trunk/drivers/md/raid1.c b/trunk/drivers/md/raid1.c
index 38f076a3400d..ff61b309129a 100644
--- a/trunk/drivers/md/raid1.c
+++ b/trunk/drivers/md/raid1.c
@@ -704,13 +704,20 @@ static void freeze_array(conf_t *conf)
 	/* stop syncio and normal IO and wait for everything to
 	 * go quite.
 	 * We increment barrier and nr_waiting, and then
-	 * wait until barrier+nr_pending match nr_queued+2
+	 * wait until nr_pending match nr_queued+1
+	 * This is called in the context of one normal IO request
+	 * that has failed. Thus any sync request that might be pending
+	 * will be blocked by nr_pending, and we need to wait for
+	 * pending IO requests to complete or be queued for re-try.
+	 * Thus the number queued (nr_queued) plus this request (1)
+	 * must match the number of pending IOs (nr_pending) before
+	 * we continue.
 	 */
 	spin_lock_irq(&conf->resync_lock);
 	conf->barrier++;
 	conf->nr_waiting++;
 	wait_event_lock_irq(conf->wait_barrier,
-			    conf->barrier+conf->nr_pending == conf->nr_queued+2,
+			    conf->nr_pending == conf->nr_queued+1,
 			    conf->resync_lock,
 			    ({ flush_pending_writes(conf);
 			       raid1_unplug(conf->mddev->queue); }));
diff --git a/trunk/drivers/md/raid10.c b/trunk/drivers/md/raid10.c
index 6c486d839c99..8e5671d2f3d3 100644
--- a/trunk/drivers/md/raid10.c
+++ b/trunk/drivers/md/raid10.c
@@ -747,13 +747,20 @@ static void freeze_array(conf_t *conf)
 	/* stop syncio and normal IO and wait for everything to
 	 * go quiet.
 	 * We increment barrier and nr_waiting, and then
-	 * wait until barrier+nr_pending match nr_queued+2
+	 * wait until nr_pending match nr_queued+1
+	 * This is called in the context of one normal IO request
+	 * that has failed. Thus any sync request that might be pending
+	 * will be blocked by nr_pending, and we need to wait for
+	 * pending IO requests to complete or be queued for re-try.
+	 * Thus the number queued (nr_queued) plus this request (1)
+	 * must match the number of pending IOs (nr_pending) before
+	 * we continue.
 	 */
 	spin_lock_irq(&conf->resync_lock);
 	conf->barrier++;
 	conf->nr_waiting++;
 	wait_event_lock_irq(conf->wait_barrier,
-			    conf->barrier+conf->nr_pending == conf->nr_queued+2,
+			    conf->nr_pending == conf->nr_queued+1,
 			    conf->resync_lock,
 			    ({ flush_pending_writes(conf);
 			       raid10_unplug(conf->mddev->queue); }));