Commit bed2213d authored by Bart Van Assche's avatar Bart Van Assche Committed by Martin K. Petersen
Browse files

scsi: Use blk_mq_rq_to_pdu() to convert a request to a SCSI command pointer 



Since commit e9c787e6 ("scsi: allocate scsi_cmnd structures as
part of struct request") struct request and struct scsi_cmnd are
adjacent. This means that there is now an alternative to reading
req->special to convert a pointer to a prepared request into a
SCSI command pointer, namely by using blk_mq_rq_to_pdu(). Make
this change where appropriate. Although this patch does not
change any functionality, it slightly improves performance and
slightly improves readability.

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>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent e7008ff5

drivers/scsi/scsi_error.c

+1 −1
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd) 
 */

enum blk_eh_timer_return scsi_times_out(struct request *req)

{

	struct scsi_cmnd *scmd = req->special;

	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);

	enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;

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

drivers/scsi/scsi_lib.c

+9 −9
Original line number Diff line number Diff line
@@ -627,7 +627,7 @@ static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) 
static bool scsi_end_request(struct request *req, blk_status_t error,

		unsigned int bytes, unsigned int bidi_bytes)

{

	struct scsi_cmnd *cmd = req->special;

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);

	struct scsi_device *sdev = cmd->device;

	struct request_queue *q = sdev->request_queue;
@@ -1171,7 +1171,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) 


static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)

{

	struct scsi_cmnd *cmd = req->special;

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);



	/*

	 * Passthrough requests may transfer data, in which case they must
@@ -1202,7 +1202,7 @@ static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req) 
 */

static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)

{

	struct scsi_cmnd *cmd = req->special;

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);



	if (unlikely(sdev->handler && sdev->handler->prep_fn)) {

		int ret = sdev->handler->prep_fn(sdev, req);
@@ -1217,7 +1217,7 @@ static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) 


static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)

{

	struct scsi_cmnd *cmd = req->special;

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);



	if (!blk_rq_bytes(req))

		cmd->sc_data_direction = DMA_NONE;
@@ -1354,7 +1354,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req) 


static void scsi_unprep_fn(struct request_queue *q, struct request *req)

{

	scsi_uninit_cmd(req->special);

	scsi_uninit_cmd(blk_mq_rq_to_pdu(req));

}



/*
@@ -1545,7 +1545,7 @@ static int scsi_lld_busy(struct request_queue *q) 
 */

static void scsi_kill_request(struct request *req, struct request_queue *q)

{

	struct scsi_cmnd *cmd = req->special;

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);

	struct scsi_device *sdev;

	struct scsi_target *starget;

	struct Scsi_Host *shost;
@@ -1576,7 +1576,7 @@ static void scsi_kill_request(struct request *req, struct request_queue *q) 


static void scsi_softirq_done(struct request *rq)

{

	struct scsi_cmnd *cmd = rq->special;

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);

	unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;

	int disposition;
@@ -1764,8 +1764,8 @@ static void scsi_request_fn(struct request_queue *q) 
			blk_start_request(req);



		spin_unlock_irq(q->queue_lock);

		cmd = req->special;

		if (unlikely(cmd == NULL)) {

		cmd = blk_mq_rq_to_pdu(req);

		if (cmd != req->special) {

			printk(KERN_CRIT "impossible request in %s.\n"

					 "please mail a stack trace to "

					 "linux-scsi@vger.kernel.org\n",

include/scsi/scsi_tcq.h

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost, 


	if (!req)

		return NULL;

	return req->special;

	return blk_mq_rq_to_pdu(req);

}



#endif /* CONFIG_BLOCK */