From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH 7/7] Remove get_device() / put_device() pair from scsi_request_fn() Date: Fri, 26 Oct 2012 14:05:47 +0200 Message-ID: <508A7C9B.5020800@acm.org> References: <508A7B63.60608@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from georges.telenet-ops.be ([195.130.137.68]:37594 "EHLO georges.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932369Ab2JZMFs (ORCPT ); Fri, 26 Oct 2012 08:05:48 -0400 In-Reply-To: <508A7B63.60608@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi Cc: James Bottomley , Mike Christie , Jens Axboe , Tejun Heo , Chanho Min Since all scsi_request_fn() callers hold a reference on the SCSI device that function is invoked for and since blk_cleanup_queue() waits until scsi_request_fn() has finished it is safe to remove the get_device() / put_device() pair from scsi_request_fn(). Cc: James Bottomley Cc: Mike Christie Cc: Jens Axboe Cc: Tejun Heo Signed-off-by: Bart Van Assche --- drivers/scsi/scsi_lib.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index c5d4ec2..71bddec 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1516,16 +1516,14 @@ static void scsi_softirq_done(struct request *rq) * Lock status: IO request lock assumed to be held when called. */ static void scsi_request_fn(struct request_queue *q) + __releases(q->queue_lock) + __acquires(q->queue_lock) { struct scsi_device *sdev = q->queuedata; struct Scsi_Host *shost; struct scsi_cmnd *cmd; struct request *req; - if(!get_device(&sdev->sdev_gendev)) - /* We must be tearing the block queue down already */ - return; - /* * To start with, we keep looping until the queue is empty, or until * the host is no longer able to accept any more requests. @@ -1634,11 +1632,7 @@ out_delay: if (sdev->device_busy == 0) blk_delay_queue(q, SCSI_QUEUE_DELAY); out: - /* must be careful here...if we trigger the ->remove() function - * we cannot be holding the q lock */ - spin_unlock_irq(q->queue_lock); - put_device(&sdev->sdev_gendev); - spin_lock_irq(q->queue_lock); + ; } u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) -- 1.7.10.4