From: Dan Williams <dan.j.williams@intel.com>
Date: Tue, 16 Jun 2009 23:00:33 +0000 (-0700)
Subject: md/raid5: add missing call to schedule() after prepare_to_wait()
X-Git-Tag: v2.6.29.6~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7786253062211453885cb7e86528ff96e9099268;p=thirdparty%2Fkernel%2Fstable.git

md/raid5: add missing call to schedule() after prepare_to_wait()

commit 7a3ab908948b6296ee7e81d42f7c176361c51975 upstream.

In the unlikely event that reshape progresses past the current request
while it is waiting for a stripe we need to schedule() before retrying
for 2 reasons:
1/ Prevent list corruption from duplicated list_add() calls without
   intervening list_del().
2/ Give the reshape code a chance to make some progress to resolve the
   conflict.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a5ba080d303b9..b437eb65e9891 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3465,6 +3465,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
 				spin_unlock_irq(&conf->device_lock);
 				if (must_retry) {
 					release_stripe(sh);
+					schedule();
 					goto retry;
 				}
 			}