If we cannot queue a request in scsi_queue_rq(), then we may error out with an error code which means that the block layer ends the request (and does not requeue). Such an error scenario would be scsi_device transport offline.
In this case, we should update the request to deal with when SCMD_MPATH_IO_STATS and SCMD_MPATH_IO_STATS flags have been set. Signed-off-by: John Garry <[email protected]> --- drivers/scsi/scsi_lib.c | 3 +++ drivers/scsi/scsi_multipath.c | 35 +++++++++++++++++++++++++++++++++++ include/scsi/scsi_multipath.h | 5 +++++ 3 files changed, 43 insertions(+) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 13562c0ab48b..a5a2967d17a2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1996,6 +1996,9 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, cmd->result = DID_NO_CONNECT << 16; else cmd->result = DID_ERROR << 16; + + if (sdev->scsi_mpath_dev && is_mpath_request(req)) + scsi_mpath_end_request_no_update(req, ret); /* * Make sure to release all allocated resources when * we hit an error, as we will never see this command diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c index 93a4545f1dbf..bec6dd94f3be 100644 --- a/drivers/scsi/scsi_multipath.c +++ b/drivers/scsi/scsi_multipath.c @@ -614,6 +614,41 @@ bool scsi_mpath_end_request(struct request *req, blk_status_t error, return false; } +void scsi_mpath_end_request_no_update(struct request *req, blk_status_t error) +{ + struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req); + struct scsi_device *sdev = scmd->device; + struct bio *clone = req->bio, *master = clone->bi_private; + struct block_device *bi_bdev = master->bi_bdev; + unsigned int nr_bytes; + + /* Don't generate error logs if we are going to try another path */ + if (blk_path_error(error)) + req->rq_flags |= RQF_QUIET; + + if (scmd->flags & SCMD_MPATH_CNT_ACTIVE) { + struct Scsi_Host *shost = sdev->host; + + atomic_dec_if_positive(&shost->mpath_nr_active); + } + + if (!(scmd->flags & SCMD_MPATH_IO_STATS)) + return; + + /* + * blk_rq_bytes() value should never exceed start_bytes, but check in + * case. + */ + if (scmd->start_bytes > blk_rq_bytes(req)) + nr_bytes = scmd->start_bytes - blk_rq_bytes(req); + else + nr_bytes = 0; + + bdev_end_io_acct(bi_bdev, req_op(req), + nr_bytes >> SECTOR_SHIFT, + scmd->start_time); +} + int __init scsi_multipath_init(void) { return class_register(&scsi_mpath_device_class); diff --git a/include/scsi/scsi_multipath.h b/include/scsi/scsi_multipath.h index dca1307c9fa4..72ad109a9a81 100644 --- a/include/scsi/scsi_multipath.h +++ b/include/scsi/scsi_multipath.h @@ -60,6 +60,7 @@ void scsi_mpath_revalidate_paths(struct scsi_mpath_device *scsi_mpath_dev); void scsi_mpath_start_request(struct request *req); bool scsi_mpath_end_request(struct request *req, blk_status_t error, unsigned int nr_bytes); +void scsi_mpath_end_request_no_update(struct request *req, blk_status_t error); #else /* CONFIG_SCSI_MULTIPATH */ struct scsi_mpath_head { @@ -120,5 +121,9 @@ static inline bool scsi_mpath_end_request(struct request *req, blk_status_t erro { return false; } +static inline void scsi_mpath_end_request_no_update(struct request *req, + blk_status_t error) +{ +} #endif /* CONFIG_SCSI_MULTIPATH */ #endif /* _SCSI_SCSI_MULTIPATH_H */ -- 2.43.0
