Commit a1bf9d1d authored by Tejun Heo 's avatar Tejun Heo Committed by James Bottomley
Browse files

[SCSI] make scsi_queue_insert() use blk_requeue_request() 



scsi_queue_insert() used to use blk_insert_request() for requeueing
requests.  This depends on the unobvious behavior of
blk_insert_request() setting REQ_SPECIAL and REQ_SOFTBARRIER when
requeueing.  This patch makes scsi_queue_insert() use
blk_requeue_request().  As REQ_SPECIAL means special requests and
REQ_SOFTBARRIER is automatically handled by blk layer now, no flag
needs to be set.

Note that scsi_queue_insert() now calls scsi_run_queue() itself, and
the prototype of the function is added right above
scsi_queue_insert().  This is temporary, as later requeue path
consolidation patchset removes scsi_queue_insert().  By adding
temporary prototype, we can do away with unnecessarily moving
functions.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 283369cc

drivers/scsi/scsi_lib.c

+14 −5
Original line number Diff line number Diff line
@@ -96,6 +96,8 @@ int scsi_insert_special_req(struct scsi_request *sreq, int at_head) 
	return 0;

}



static void scsi_run_queue(struct request_queue *q);



/*

 * Function:    scsi_queue_insert()

 *
@@ -119,6 +121,8 @@ int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) 
{

	struct Scsi_Host *host = cmd->device->host;

	struct scsi_device *device = cmd->device;

	struct request_queue *q = device->request_queue;

	unsigned long flags;



	SCSI_LOG_MLQUEUE(1,

		 printk("Inserting command %p into mlqueue\n", cmd));
@@ -160,17 +164,22 @@ int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) 
	scsi_device_unbusy(device);



	/*

	 * Insert this command at the head of the queue for it's device.

	 * It will go before all other commands that are already in the queue.

	 * Requeue this command.  It will go before all other commands

	 * that are already in the queue.

	 *

	 * NOTE: there is magic here about the way the queue is plugged if

	 * we have no outstanding commands.

	 * 

	 * Although this *doesn't* plug the queue, it does call the request

	 * Although we *don't* plug the queue, we call the request

	 * function.  The SCSI request function detects the blocked condition

	 * and plugs the queue appropriately.

         */

	blk_insert_request(device->request_queue, cmd->request, 1, cmd, 1);

	spin_lock_irqsave(q->queue_lock, flags);

	blk_requeue_request(q, cmd->request);

	spin_unlock_irqrestore(q->queue_lock, flags);



	scsi_run_queue(q);



	return 0;

}

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