From a45ffd896ad8b45901917edb845d4011db46d6b4 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Mon, 14 Aug 2017 10:40:41 +0100
Subject: [PATCH] [block-cache] writeback could get stuck in a loop
If a block had a non zero ref count.
---
block-cache/block_cache.cc | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/block-cache/block_cache.cc b/block-cache/block_cache.cc
index 5e72cd8..f20a210 100644
--- a/block-cache/block_cache.cc
+++ b/block-cache/block_cache.cc
@@ -265,13 +265,11 @@ block_cache::writeback(unsigned count)
if (actual == count)
break;
- // The block may be on the dirty list from a prior
- // acquisition.
- if (it->ref_count_)
- continue;
-
- issue_write(*it);
- actual++;
+ // We can't writeback anything that's still in use.
+ if (!it->ref_count_) {
+ issue_write(*it);
+ actual++;
+ }
it = next;
}