Commit 551eb598 authored by Bart Van Assche's avatar Bart Van Assche Committed by Martin K. Petersen
Browse files

scsi: Split scsi_internal_device_block() 



Instead of passing a "wait" argument to scsi_internal_device_block(),
split this function into a function that waits and a function that
doesn't wait. This will make it easier to serialize SCSI device state
changes through a mutex.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 8e688254

drivers/scsi/mpt3sas/mpt3sas_scsih.c

+2 −2
Original line number Diff line number Diff line
@@ -2859,7 +2859,7 @@ _scsih_internal_device_block(struct scsi_device *sdev, 
	    sas_device_priv_data->sas_target->handle);

	sas_device_priv_data->block = 1;



	r = scsi_internal_device_block(sdev, false);

	r = scsi_internal_device_block_nowait(sdev);

	if (r == -EINVAL)

		sdev_printk(KERN_WARNING, sdev,

		    "device_block failed with return(%d) for handle(0x%04x)\n",
@@ -2895,7 +2895,7 @@ _scsih_internal_device_unblock(struct scsi_device *sdev, 
		    "performing a block followed by an unblock\n",

		    r, sas_device_priv_data->sas_target->handle);

		sas_device_priv_data->block = 1;

		r = scsi_internal_device_block(sdev, false);

		r = scsi_internal_device_block_nowait(sdev);

		if (r)

			sdev_printk(KERN_WARNING, sdev, "retried device_block "

			    "failed with return(%d) for handle(0x%04x)\n",

drivers/scsi/scsi_lib.c

+47 −26
Original line number Diff line number Diff line
@@ -2944,28 +2944,20 @@ scsi_target_resume(struct scsi_target *starget) 
EXPORT_SYMBOL(scsi_target_resume);



/**

 * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state

 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state

 * @sdev: device to block

 * @wait:	Whether or not to wait until ongoing .queuecommand() /

 *		.queue_rq() calls have finished.

 *

 * Block request made by scsi lld's to temporarily stop all

 * scsi commands on the specified device. May sleep.

 * Pause SCSI command processing on the specified device. Does not sleep.

 *

 * Returns zero if successful or error if not

 * Returns zero if successful or a negative error code upon failure.

 *

 * Notes:

 *	This routine transitions the device to the SDEV_BLOCK state

 *	(which must be a legal transition).  When the device is in this

 *	state, all commands are deferred until the scsi lld reenables

 *	the device with scsi_device_unblock or device_block_tmo fires.

 *

 * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after

 * scsi_internal_device_block() has blocked a SCSI device and also

 * remove the rport mutex lock and unlock calls from srp_queuecommand().

 * This routine transitions the device to the SDEV_BLOCK state (which must be

 * a legal transition). When the device is in this state, command processing

 * is paused until the device leaves the SDEV_BLOCK state. See also

 * scsi_internal_device_unblock_nowait().

 */

int

scsi_internal_device_block(struct scsi_device *sdev, bool wait)

int scsi_internal_device_block_nowait(struct scsi_device *sdev)

{

	struct request_queue *q = sdev->request_queue;

	unsigned long flags;
@@ -2985,21 +2977,50 @@ scsi_internal_device_block(struct scsi_device *sdev, bool wait) 
	 * request queue. 

	 */

	if (q->mq_ops) {

		if (wait)

			blk_mq_quiesce_queue(q);

		else

		blk_mq_stop_hw_queues(q);

	} else {

		spin_lock_irqsave(q->queue_lock, flags);

		blk_stop_queue(q);

		spin_unlock_irqrestore(q->queue_lock, flags);

		if (wait)

			scsi_wait_for_queuecommand(sdev);

	}



	return 0;

}

EXPORT_SYMBOL_GPL(scsi_internal_device_block);

EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);



/**

 * scsi_internal_device_block - try to transition to the SDEV_BLOCK state

 * @sdev: device to block

 *

 * Pause SCSI command processing on the specified device and wait until all

 * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.

 *

 * Returns zero if successful or a negative error code upon failure.

 *

 * Note:

 * This routine transitions the device to the SDEV_BLOCK state (which must be

 * a legal transition). When the device is in this state, command processing

 * is paused until the device leaves the SDEV_BLOCK state. See also

 * scsi_internal_device_unblock().

 *

 * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after

 * scsi_internal_device_block() has blocked a SCSI device and also

 * remove the rport mutex lock and unlock calls from srp_queuecommand().

 */

static int scsi_internal_device_block(struct scsi_device *sdev)

{

	struct request_queue *q = sdev->request_queue;

	int err;



	err = scsi_internal_device_block_nowait(sdev);

	if (err == 0) {

		if (q->mq_ops)

			blk_mq_quiesce_queue(q);

		else

			scsi_wait_for_queuecommand(sdev);

	}

	return err;

}

 

/**

 * scsi_internal_device_unblock - resume a device after a block request
@@ -3056,7 +3077,7 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); 
static void

device_block(struct scsi_device *sdev, void *data)

{

	scsi_internal_device_block(sdev, true);

	scsi_internal_device_block(sdev);

}



static int

include/scsi/scsi_device.h

+1 −1
Original line number Diff line number Diff line
@@ -472,7 +472,7 @@ static inline int scsi_device_created(struct scsi_device *sdev) 
		sdev->sdev_state == SDEV_CREATED_BLOCK;

}



int scsi_internal_device_block(struct scsi_device *sdev, bool wait);

int scsi_internal_device_block_nowait(struct scsi_device *sdev);

int scsi_internal_device_unblock(struct scsi_device *sdev,

				 enum scsi_device_state new_state);