linux-kernel - [PATCH] z3fold: fix spinlock unlocking in page reclaim

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Message-Id: <20170311222239.7b83d8e7ef1914e05497649f@gmail.com>
Date:   Sat, 11 Mar 2017 22:22:39 +0100
From:   Vitaly Wool <vitalywool@...il.com>
To:     Linux-MM <linux-mm@...ck.org>, linux-kernel@...r.kernel.org
Cc:     Alexey Khoroshilov <khoroshilov@...ras.ru>,
        Dan Streetman <ddstreet@...e.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Matthew Wilcox <willy@...radead.org>
Subject: [PATCH] z3fold: fix spinlock unlocking in page reclaim

The patch "z3fold: add kref refcounting" introduced a bug in
z3fold_reclaim_page() with function exit that may leave pool->lock
spinlock held. Here comes the trivial fix.

Reported-by: Alexey Khoroshilov <khoroshilov@...ras.ru>
Signed-off-by: Vitaly Wool <vitalywool@...il.com>
---
 mm/z3fold.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/z3fold.c b/mm/z3fold.c
index 8970a2f..f9492bc 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -667,6 +667,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
 			z3fold_page_unlock(zhdr);
 			spin_lock(&pool->lock);
 			if (kref_put(&zhdr->refcount, release_z3fold_page)) {
+				spin_unlock(&pool->lock);
 				atomic64_dec(&pool->pages_nr);
 				return 0;
 			}
-- 
2.5.0