REQ_FAILFAST_TRANSPORT is set by upper layer software that handles multipathing. Unlike SCSI, NVMe's error handling was specifically designed to handle local retry for non-path errors. As such, allow NVMe's local retry mechanism to be used for requests marked with REQ_FAILFAST_TRANSPORT.
In this way, the mechanism of NVMe multipath or other multipath are now equivalent. The mechanism is: non path related error will be retried locally, path related error is handled by multipath. Also, introduce FAILUP handling for REQ_FAILFAST_TRANSPORT. Update NVMe to allow failover of requests marked with either REQ_NVME_MPATH or REQ_FAILFAST_TRANSPORT. This allows such requests to be given a disposition of either FAILOVER or FAILUP respectively. nvme_complete_rq() is updated to call nvme_failup_req() if nvme_decide_disposition() returns FAILUP. nvme_failup_req() ensures the request is completed with a retryable path error. Signed-off-by: Mike Snitzer <[email protected]> --- drivers/nvme/host/core.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 540d6fd8ffef..a12b10a1383c 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -299,6 +299,7 @@ enum nvme_disposition { COMPLETE, RETRY, FAILOVER, + FAILUP, }; static inline enum nvme_disposition nvme_decide_disposition(struct request *req) @@ -306,15 +307,16 @@ static inline enum nvme_disposition nvme_decide_disposition(struct request *req) if (likely(nvme_req(req)->status == 0)) return COMPLETE; - if (blk_noretry_request(req) || + if ((req->cmd_flags & (REQ_FAILFAST_DEV | REQ_FAILFAST_DRIVER)) || (nvme_req(req)->status & NVME_SC_DNR) || nvme_req(req)->retries >= nvme_max_retries) return COMPLETE; - if (req->cmd_flags & REQ_NVME_MPATH) { + if (req->cmd_flags & (REQ_NVME_MPATH | REQ_FAILFAST_TRANSPORT)) { if (nvme_is_path_error(nvme_req(req)->status) || blk_queue_dying(req->q)) - return FAILOVER; + return (req->cmd_flags & REQ_NVME_MPATH) ? + FAILOVER : FAILUP; } else { if (blk_queue_dying(req->q)) return COMPLETE; @@ -336,6 +338,12 @@ static inline void nvme_end_req(struct request *req) blk_mq_end_request(req, status); } +static inline void nvme_failup_req(struct request *req) +{ + nvme_req(req)->status = NVME_SC_HOST_PATH_ERROR; + nvme_end_req(req); +} + void nvme_complete_rq(struct request *req) { trace_nvme_complete_rq(req); @@ -354,6 +362,9 @@ void nvme_complete_rq(struct request *req) case FAILOVER: nvme_failover_req(req); return; + case FAILUP: + nvme_failup_req(req); + return; } } EXPORT_SYMBOL_GPL(nvme_complete_rq); -- 2.15.0 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
