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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ed79d3925860..0dfec0dedd5e 100644
--- 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;