In scsi core, __scsi_queue_insert should just put request back on the queue and retry using the same command as before. However, for blk-mq, scsi_mq_requeue_cmd is employed here which will unprepare the request. To align with the semantics of __scsi_queue_insert, use blk_mq_requeue_request with kick_requeue_list == true and put the reference of scsi_device. Cc: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx> Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxx> --- Changelog: V2 -> V3: - add commit to explain why we need a put_device in __scsi_queue_insert - add reviewed-by V1 -> V2: - add put_device on scsi_device->sdev_gendev drivers/scsi/scsi_lib.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index a86df9c..d2f1838 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -191,7 +191,13 @@ 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); + /* + * scsi_device.sdev_gendev will be get every time in .get_budget and + * be put in scsi_end_request. Hence we need to put the reference + * here when we decide to requeue request. + */ + blk_mq_requeue_request(cmd->request, true); + put_device(&device->sdev_gendev); return; } spin_lock_irqsave(q->queue_lock, flags); -- 2.7.4