From: NeilBrown <neilb@suse.de>
Date: Fri, 8 May 2015 08:19:34 +0000 (+1000)
Subject: md/raid5: don't record new size if resize_stripes fails.
X-Git-Tag: v3.4.109~59
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ece8cda08af85d72b151b2071df2d92a16b291b1;p=linux

md/raid5: don't record new size if resize_stripes fails.

commit 6e9eac2dcee5e19f125967dd2be3e36558c42fff upstream.

If any memory allocation in resize_stripes fails we will return
-ENOMEM, but in some cases we update conf->pool_size anyway.

This means that if we try again, the allocations will be assumed
to be larger than they are, and badness results.

So only update pool_size if there is no error.

This bug was introduced in 2.6.17 and the patch is suitable for
-stable.

Fixes: ad01c9e3752f ("[PATCH] md: Allow stripes to be expanded in preparation for expanding an array")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c276ad09ace9..7a218e81eb39 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1622,7 +1622,8 @@ static int resize_stripes(struct r5conf *conf, int newsize)
 
 	conf->slab_cache = sc;
 	conf->active_name = 1-conf->active_name;
-	conf->pool_size = newsize;
+	if (!err)
+		conf->pool_size = newsize;
 	return err;
 }