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: v2.6.31-rc1~143^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7a3ab908948b6296ee7e81d42f7c176361c51975;p=karo-tx-linux.git

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

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.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 8f2e3740a05a..59e29c2983cb 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3695,6 +3695,7 @@ 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;
 				}
 			}