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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 2cca9cffc63f..d8099c7cab00 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1031,7 +1031,8 @@ int scsi_init_io(struct scsi_cmnd *cmd)
bool is_mq = (rq->mq_ctx != NULL);
int error;
- BUG_ON(!rq->nr_phys_segments);
+ if (WARN_ON_ONCE(!rq->nr_phys_segments))
+ return -EINVAL;
error = scsi_init_sgtable(rq, &cmd->sdb);
if (error)
@@ -2126,6 +2127,29 @@ void scsi_mq_destroy_tags(struct Scsi_Host *shost)
blk_mq_free_tag_set(&shost->tag_set);
}
+/**
+ * scsi_device_from_queue - return sdev associated with a request_queue
+ * @q: The request queue to return the sdev from
+ *
+ * Return the sdev associated with a request queue or NULL if the
+ * request_queue does not reference a SCSI device.
+ */
+struct scsi_device *scsi_device_from_queue(struct request_queue *q)
+{
+ struct scsi_device *sdev = NULL;
+
+ if (q->mq_ops) {
+ if (q->mq_ops == &scsi_mq_ops)
+ sdev = q->queuedata;
+ } else if (q->request_fn == scsi_request_fn)
+ sdev = q->queuedata;
+ if (!sdev || !get_device(&sdev->sdev_gendev))
+ sdev = NULL;
+
+ return sdev;
+}
+EXPORT_SYMBOL_GPL(scsi_device_from_queue);
+
/*
* Function: scsi_block_requests()
*