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

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")
Cc: stable@vger.kernel.org (v2.6.17+)
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 85dc0e67fb883d24183a1f5c18793288235409ec..9748e525e4c0378ab123ccd1e6f578b575bb31f7 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2216,7 +2216,8 @@ 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;
 }