Merge tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb...

[platform/kernel/linux-rpi.git] / drivers / scsi / scsi_lib.c

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ed79d39..0dfec0d 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -191,7 +191,19 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
         */
        cmd->result = 0;
        if (q->mq_ops) {
-               scsi_mq_requeue_cmd(cmd);
+               /*
+                * Before a SCSI command is dispatched,
+                * get_device(&sdev->sdev_gendev) is called and the host,
+                * target and device busy counters are increased. Since
+                * requeuing a request causes these actions to be repeated and
+                * since scsi_device_unbusy() has already been called,
+                * put_device(&device->sdev_gendev) must still be called. Call
+                * put_device() after blk_mq_requeue_request() to avoid that
+                * removal of the SCSI device can start before requeueing has
+                * happened.
+                */
+               blk_mq_requeue_request(cmd->request, true);
+               put_device(&device->sdev_gendev);
                return;
        }
        spin_lock_irqsave(q->queue_lock, flags);
@@ -858,6 +870,17 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                /* for passthrough error may be set */
                error = BLK_STS_OK;
        }
+       /*
+        * Another corner case: the SCSI status byte is non-zero but 'good'.
+        * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
+        * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
+        * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
+        * intermediate statuses (both obsolete in SAM-4) as good.
+        */
+       if (status_byte(result) && scsi_status_is_good(result)) {
+               result = 0;
+               error = BLK_STS_OK;
+       }
 
        /*
         * special case: failed zero length commands always need to
@@ -2611,7 +2634,7 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
        /* try to eat the UNIT_ATTENTION if there are enough retries */
        do {
                result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
-                                         timeout, retries, NULL);
+                                         timeout, 1, NULL);
                if (sdev->removable && scsi_sense_valid(sshdr) &&
                    sshdr->sense_key == UNIT_ATTENTION)
                        sdev->changed = 1;