From bed2213d01de474eb8a6f3891070eec6be6fe772 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 25 Aug 2017 13:46:32 -0700 Subject: [PATCH] scsi: Use blk_mq_rq_to_pdu() to convert a request to a SCSI command pointer Since commit e9c787e65c0c ("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 Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_error.c | 2 +- drivers/scsi/scsi_lib.c | 18 +++++++++--------- include/scsi/scsi_tcq.h | 2 +- 3 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 01b2d2055edf..38942050b265 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -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; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9e8ce0d66c5a..0270b35f7680 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -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", diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h index 4416b1026189..5b416debf101 100644 --- a/include/scsi/scsi_tcq.h +++ b/include/scsi/scsi_tcq.h @@ -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 */ -- 2.20.1