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Commit 9d112517 authored by Kiyoshi Ueda's avatar Kiyoshi Ueda Committed by James Bottomley
Browse files

[SCSI] refactor sdev/starget/shost busy checking 



This patch refactors the busy checking codes of scsi_device,
Scsi_Host and scsi_target.  There should be no functional change.

This is a preparation for another patch which exports scsi's busy
state to the block layer for request stacking drivers.

Signed-off-by: default avatarKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 22ab019b

drivers/scsi/scsi_lib.c

+20 −10
Original line number Diff line number Diff line
@@ -529,6 +529,14 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev) 
	spin_unlock_irqrestore(shost->host_lock, flags);

}



static inline int scsi_device_is_busy(struct scsi_device *sdev)

{

	if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked)

		return 1;



	return 0;

}



static inline int scsi_target_is_busy(struct scsi_target *starget)

{

	return ((starget->can_queue > 0 &&
@@ -536,6 +544,15 @@ static inline int scsi_target_is_busy(struct scsi_target *starget) 
		 starget->target_blocked);

}



static inline int scsi_host_is_busy(struct Scsi_Host *shost)

{

	if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||

	    shost->host_blocked || shost->host_self_blocked)

		return 1;



	return 0;

}



/*

 * Function:	scsi_run_queue()

 *
@@ -558,11 +575,7 @@ static void scsi_run_queue(struct request_queue *q) 
		scsi_single_lun_run(sdev);



	spin_lock_irqsave(shost->host_lock, flags);

	while (!list_empty(&shost->starved_list) &&

	       !shost->host_blocked && !shost->host_self_blocked &&

		!((shost->can_queue > 0) &&

		  (shost->host_busy >= shost->can_queue))) {



	while (!list_empty(&shost->starved_list) && !scsi_host_is_busy(shost)) {

		int flagset;



		/*
@@ -1348,8 +1361,6 @@ int scsi_prep_fn(struct request_queue *q, struct request *req) 
static inline int scsi_dev_queue_ready(struct request_queue *q,

				  struct scsi_device *sdev)

{

	if (sdev->device_busy >= sdev->queue_depth)

		return 0;

	if (sdev->device_busy == 0 && sdev->device_blocked) {

		/*

		 * unblock after device_blocked iterates to zero
@@ -1363,7 +1374,7 @@ static inline int scsi_dev_queue_ready(struct request_queue *q, 
			return 0;

		}

	}

	if (sdev->device_blocked)

	if (scsi_device_is_busy(sdev))

		return 0;



	return 1;
@@ -1440,8 +1451,7 @@ static inline int scsi_host_queue_ready(struct request_queue *q, 
			return 0;

		}

	}

	if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||

	    shost->host_blocked || shost->host_self_blocked) {

	if (scsi_host_is_busy(shost)) {

		if (list_empty(&sdev->starved_entry))

			list_add_tail(&sdev->starved_entry, &shost->starved_list);

		return 0;