From: Loic Dachary <ldachary@redhat.com>
Date: Wed, 15 Feb 2017 20:46:26 +0000 (+0100)
Subject: crush: allow uniform buckets with no items
X-Git-Tag: v12.0.1~293^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=d4990c9d98bb16fa8b2f2d9cd6108afc9f86f7a1;p=ceph.git

crush: allow uniform buckets with no items

When a uniform bucket is created with zero size, it returns on error
because crush_multiplication_is_unsafe returns false. Since the goal
of this safegard is to avoid overflow, it should not fail.

Signed-off-by: Loic Dachary <ldachary@redhat.com>
---

diff --git a/src/crush/builder.c b/src/crush/builder.c
index 71a6264e76a91..364db9256c07c 100644
--- a/src/crush/builder.c
+++ b/src/crush/builder.c
@@ -1416,6 +1416,8 @@ int crush_addition_is_unsafe(__u32 a, __u32 b)
 int crush_multiplication_is_unsafe(__u32  a, __u32 b)
 {
 	/* prevent division by zero */
+        if (!a)
+                return 0;
 	if (!b)
 		return 1;
 	if ((((__u32)(-1)) / b) < a)