Now that 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().

Signed-off-by: Bart Van Assche <bvanass...@acm.org>
Acked-by: Tejun Heo <t...@kernel.org>
Cc: James Bottomley <jbottom...@parallels.com>
Cc: Hannes Reinecke <h...@suse.de>
Cc: Mike Christie <micha...@cs.wisc.edu>
---
 drivers/scsi/scsi_lib.c |   14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d6ca072..03d4165 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1533,16 +1533,14 @@ 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.
@@ -1631,7 +1629,7 @@ static void scsi_request_fn(struct request_queue *q)
                        goto out_delay;
        }
 
-       goto out;
+       return;
 
  not_ready:
        spin_unlock_irq(shost->host_lock);
@@ -1650,12 +1648,6 @@ static void scsi_request_fn(struct request_queue *q)
 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

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