scsi: core: Only process PM requests if rpm_status != RPM_ACTIVE

Instead of submitting all SCSI commands submitted with scsi_execute() to a
SCSI device if rpm_status != RPM_ACTIVE, only submit RQF_PM (power
management requests) if rpm_status != RPM_ACTIVE. This patch makes the SCSI
core handle the runtime power management status (rpm_status) as it should
be handled.

Link: https://lore.kernel.org/r/20201209052951.16136-7-bvanassche@acm.org
Cc: Can Guo <cang@codeaurora.org>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b7ac145..91bc39a 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -249,7 +249,8 @@ int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 
        req = blk_get_request(sdev->request_queue,
                        data_direction == DMA_TO_DEVICE ?
-                       REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
+                       REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
+                       rq_flags & RQF_PM ? BLK_MQ_REQ_PM : 0);
        if (IS_ERR(req))
                return ret;
        rq = scsi_req(req);
@@ -1206,6 +1207,8 @@ static blk_status_t
 scsi_device_state_check(struct scsi_device *sdev, struct request *req)
 {
        switch (sdev->sdev_state) {
+       case SDEV_CREATED:
+               return BLK_STS_OK;
        case SDEV_OFFLINE:
        case SDEV_TRANSPORT_OFFLINE:
                /*
@@ -1232,18 +1235,18 @@ scsi_device_state_check(struct scsi_device *sdev, struct request *req)
                return BLK_STS_RESOURCE;
        case SDEV_QUIESCE:
                /*
-                * If the devices is blocked we defer normal commands.
+                * If the device is blocked we only accept power management
+                * commands.
                 */
-               if (req && !(req->rq_flags & RQF_PREEMPT))
+               if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM)))
                        return BLK_STS_RESOURCE;
                return BLK_STS_OK;
        default:
                /*
                 * For any other not fully online state we only allow
-                * special commands.  In particular any user initiated
-                * command is not allowed.
+                * power management commands.
                 */
-               if (req && !(req->rq_flags & RQF_PREEMPT))
+               if (req && !(req->rq_flags & RQF_PM))
                        return BLK_STS_IOERR;
                return BLK_STS_OK;
        }
@@ -2517,15 +2520,13 @@ void sdev_evt_send_simple(struct scsi_device *sdev,
 EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
 
 /**
- *     scsi_device_quiesce - Block user issued commands.
+ *     scsi_device_quiesce - Block all commands except power management.
  *     @sdev:  scsi device to quiesce.
  *
  *     This works by trying to transition to the SDEV_QUIESCE state
  *     (which must be a legal transition).  When the device is in this
- *     state, only special requests will be accepted, all others will
- *     be deferred.  Since special requests may also be requeued requests,
- *     a successful return doesn't guarantee the device will be
- *     totally quiescent.
+ *     state, only power management requests will be accepted, all others will
+ *     be deferred.
  *
  *     Must be called with user context, may sleep.
  *
@@ -2587,12 +2588,12 @@ void scsi_device_resume(struct scsi_device *sdev)
         * device deleted during suspend)
         */
        mutex_lock(&sdev->state_mutex);
+       if (sdev->sdev_state == SDEV_QUIESCE)
+               scsi_device_set_state(sdev, SDEV_RUNNING);
        if (sdev->quiesced_by) {
                sdev->quiesced_by = NULL;
                blk_clear_pm_only(sdev->request_queue);
        }
-       if (sdev->sdev_state == SDEV_QUIESCE)
-               scsi_device_set_state(sdev, SDEV_RUNNING);
        mutex_unlock(&sdev->state_mutex);
 }
 EXPORT_SYMBOL(scsi_device_resume);