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[95.166.82.66]) by smtp.gmail.com with ESMTPSA id v64sm2764583lfa.48.2018.12.11.11.17.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Dec 2018 11:17:17 -0800 (PST) From: =?UTF-8?q?Matias=20Bj=C3=B8rling?= To: axboe@fb.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Matias=20Bj=C3=B8rling?= Subject: [GIT PULL 15/21] lightnvm: pblk: avoid ref warning on cache creation Date: Tue, 11 Dec 2018 20:16:21 +0100 Message-Id: <20181211191627.15542-16-mb@lightnvm.io> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181211191627.15542-1-mb@lightnvm.io> References: <20181211191627.15542-1-mb@lightnvm.io> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Javier González The current kref implementation around pblk global caches triggers a false positive on refcount_inc_checked() (when called) as the kref is initialized to 0. Instead of usint kref_inc() on a 0 reference, which is in principle correct, use kref_init() to avoid the check. This is also more explicit about what actually happens on cache creation. In the process, do a small refactoring to use kref helpers. Fixes: 1864de94ec9d6 "lightnvm: pblk: stop recreating global caches" Signed-off-by: Javier González Reviewed-by: Hans Holmberg Signed-off-by: Matias Bjørling --- drivers/lightnvm/pblk-init.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c index 0e37104de596..72ad3e70318c 100644 --- a/drivers/lightnvm/pblk-init.c +++ b/drivers/lightnvm/pblk-init.c @@ -347,23 +347,19 @@ static int pblk_create_global_caches(void) static int pblk_get_global_caches(void) { - int ret; + int ret = 0; mutex_lock(&pblk_caches.mutex); - if (kref_read(&pblk_caches.kref) > 0) { - kref_get(&pblk_caches.kref); - mutex_unlock(&pblk_caches.mutex); - return 0; - } + if (kref_get_unless_zero(&pblk_caches.kref)) + goto out; ret = pblk_create_global_caches(); - if (!ret) - kref_get(&pblk_caches.kref); + kref_init(&pblk_caches.kref); +out: mutex_unlock(&pblk_caches.mutex); - return ret; } -- 2.17.1