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

Since commit e9c787e65c ("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: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche 2017-08-25 13:46:32 -07:00 committed by Martin K. Petersen
parent e7008ff5c6
commit bed2213d01
3 changed files with 11 additions and 11 deletions

View File

@ -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;

View File

@ -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 @@ out:
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",

View File

@ -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 */