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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index cd2f96b2c57263628ef0816af3b114ad9437b740..007ab861eca00365d89c08c69741c84f58a02510 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1933,7 +1933,8 @@ 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;
 }