From: NeilBrown <neilb@suse.de>
Date: Tue, 3 Jul 2012 02:13:29 +0000 (+1000)
Subject: md/raid5: fix refcount problem when blocked_rdev is set.
X-Git-Tag: v3.5-rc7~8^2~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5f066c632fcfd2a33f2eb7077c15c630e9f5ea5b;p=profile%2Fivi%2Fkernel-x86-ivi.git

md/raid5: fix refcount problem when blocked_rdev is set.

commit 43220aa0f22cd3ce5b30246d50ccd696d119edea
    md/raid5: fix a hang on device failure.

fixed a hang, but introduced a refcounting in-balance so
that if the presence of bad-blocks ever caused an rdev to
be 'blocked' we would increment the refcount on the rdev and
never decrement it.

So added the needed rdev_dec_pending when md_wait_for_blocked_rdev
is not called.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index befadb4..62b6b3a 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3588,8 +3588,18 @@ static void handle_stripe(struct stripe_head *sh)
 
 finish:
 	/* wait for this device to become unblocked */
-	if (conf->mddev->external && unlikely(s.blocked_rdev))
-		md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev);
+	if (unlikely(s.blocked_rdev)) {
+		if (conf->mddev->external)
+			md_wait_for_blocked_rdev(s.blocked_rdev,
+						 conf->mddev);
+		else
+			/* Internal metadata will immediately
+			 * be written by raid5d, so we don't
+			 * need to wait here.
+			 */
+			rdev_dec_pending(s.blocked_rdev,
+					 conf->mddev);
+	}
 
 	if (s.handle_bad_blocks)
 		for (i = disks; i--; ) {