From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Alan Stern , Christoph Hellwig , Bart Van Assche , Jianchao Wang , Hannes Reinecke , Johannes Thumshirn , Adrian Hunter , "James E.J. Bottomley" , "Martin K. Petersen" , linux-scsi@vger.kernel.org Subject: [RFC PATCH V2 07/17] SCSI: prepare for introducing admin queue for legacy path Date: Sat, 11 Aug 2018 15:12:10 +0800 Message-Id: <20180811071220.357-8-ming.lei@redhat.com> In-Reply-To: <20180811071220.357-1-ming.lei@redhat.com> References: <20180811071220.357-1-ming.lei@redhat.com> List-ID: Uses scsi_is_admin_queue() and scsi_get_scsi_dev() to retrieve 'scsi_device' for legacy path. The same approach can be used in SCSI_MQ path too, just not very efficiently, and will deal with that in the patch when introducing admin queue for SCSI_MQ. Cc: Alan Stern Cc: Christoph Hellwig Cc: Bart Van Assche Cc: Jianchao Wang Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: Adrian Hunter Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org Signed-off-by: Ming Lei --- drivers/scsi/scsi_lib.c | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 62699adaef61..d0da89322425 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -46,6 +46,20 @@ static DEFINE_MUTEX(scsi_sense_cache_mutex); static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd); +/* For admin queue, its queuedata is NULL */ +static inline bool scsi_is_admin_queue(struct request_queue *q) +{ + return !q->queuedata; +} + +/* This helper can only be used in req prep stage */ +static inline struct scsi_device *scsi_get_scsi_dev(struct request *rq) +{ + if (scsi_is_admin_queue(rq->q)) + return scsi_req(rq)->sdev; + return rq->q->queuedata; +} + static inline struct kmem_cache * scsi_select_sense_cache(bool unchecked_isa_dma) { @@ -1376,10 +1390,9 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req) } static int -scsi_prep_return(struct request_queue *q, struct request *req, int ret) +scsi_prep_return(struct scsi_device *sdev, struct request_queue *q, + struct request *req, int ret) { - struct scsi_device *sdev = q->queuedata; - switch (ret) { case BLKPREP_KILL: case BLKPREP_INVALID: @@ -1411,7 +1424,7 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret) static int scsi_prep_fn(struct request_queue *q, struct request *req) { - struct scsi_device *sdev = q->queuedata; + struct scsi_device *sdev = scsi_get_scsi_dev(req); struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); int ret; @@ -1436,7 +1449,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req) ret = scsi_setup_cmnd(sdev, req); out: - return scsi_prep_return(q, req, ret); + return scsi_prep_return(sdev, q, req, ret); } static void scsi_unprep_fn(struct request_queue *q, struct request *req) @@ -1613,6 +1626,9 @@ static int scsi_lld_busy(struct request_queue *q) if (blk_queue_dying(q)) return 0; + if (WARN_ON_ONCE(scsi_is_admin_queue(q))) + return 0; + shost = sdev->host; /* @@ -1816,7 +1832,7 @@ static void scsi_request_fn(struct request_queue *q) __releases(q->queue_lock) __acquires(q->queue_lock) { - struct scsi_device *sdev = q->queuedata; + struct scsi_device *sdev; struct Scsi_Host *shost; struct scsi_cmnd *cmd; struct request *req; @@ -1825,7 +1841,6 @@ static void scsi_request_fn(struct request_queue *q) * To start with, we keep looping until the queue is empty, or until * the host is no longer able to accept any more requests. */ - shost = sdev->host; for (;;) { int rtn; /* @@ -1837,6 +1852,10 @@ static void scsi_request_fn(struct request_queue *q) if (!req) break; + cmd = blk_mq_rq_to_pdu(req); + sdev = cmd->device; + shost = sdev->host; + if (unlikely(!scsi_device_online(sdev))) { sdev_printk(KERN_ERR, sdev, "rejecting I/O to offline device\n"); @@ -1854,7 +1873,6 @@ static void scsi_request_fn(struct request_queue *q) blk_start_request(req); spin_unlock_irq(q->queue_lock); - 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 " @@ -2332,6 +2350,9 @@ struct scsi_device *scsi_device_from_queue(struct request_queue *q) { struct scsi_device *sdev = NULL; + /* admin queue won't be exposed to external users */ + WARN_ON_ONCE(scsi_is_admin_queue(q)); + if (q->mq_ops) { if (q->mq_ops == &scsi_mq_ops) sdev = q->queuedata; -- 2.9.5