nvme: update failover handling to work with REQ_FAILFAST_TRANSPORT
From: Mike Snitzer <hidden>
Date: 2021-04-15 23:11:45
Also in:
dm-devel
BZ: 1948690
Upstream Status: RHEL-only
Signed-off-by: Mike Snitzer <redacted>
rhel-8.git commit f8fb6ea1226e2abc525c88da13b346118d548eea
Author: Mike Snitzer [off-list ref]
Date: Tue Aug 25 21:52:46 2020 -0400
[nvme] nvme: update failover handling to work with REQ_FAILFAST_TRANSPORT
Message-id: [off-list ref]
Patchwork-id: 325177
Patchwork-instance: patchwork
O-Subject: [RHEL8.3 PATCH 08/10] nvme: update failover handling to work with REQ_FAILFAST_TRANSPORT
Bugzilla: 1843515
RH-Acked-by: David Milburn [off-list ref]
RH-Acked-by: Gopal Tiwari [off-list ref]
RH-Acked-by: Ewan Milne [off-list ref]
BZ: 1843515
Upstream Status: RHEL-only
If REQ_FAILFAST_TRANSPORT is set it means the driver should not retry
IO that completed with transport errors. REQ_FAILFAST_TRANSPORT is
set by multipathing software (e.g. dm-multipath) before it issues IO.
Update NVMe to prepare for failover of requests marked with either
REQ_NVME_MPATH or REQ_FAILFAST_TRANSPORT. This allows such requests
to be given a disposition of FAILOVER.
Introduce nvme_end_req_with_failover() for use in nvme_complete_rq()
if REQ_NVME_MPATH isn't set. nvme_end_req_with_failover() ensures
request is completed with a retryable IO error when appropriate.
__nvme_end_req() was factored out for use by both nvme_end_req() and
nvme_end_req_with_failover().
Signed-off-by: Mike Snitzer [off-list ref]
Signed-off-by: Frantisek Hrbata [off-list ref]
---
drivers/nvme/host/core.c | 33 ++++++++++++++++++++++++++++-----
1 file changed, 28 insertions(+), 5 deletions(-)
Index: linux-rhel9/drivers/nvme/host/core.c
===================================================================--- linux-rhel9.orig/drivers/nvme/host/core.c
+++ linux-rhel9/drivers/nvme/host/core.c@@ -311,7 +311,7 @@ static inline enum nvme_disposition nvme 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;
@@ -323,10 +323,8 @@ static inline enum nvme_disposition nvme return RETRY; } -static inline void nvme_end_req(struct request *req) +static inline void __nvme_end_req(struct request *req, blk_status_t status) { - blk_status_t status = nvme_error_status(nvme_req(req)->status); - if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && req_op(req) == REQ_OP_ZONE_APPEND) req->__sector = nvme_lba_to_sect(req->q->queuedata,
@@ -336,6 +334,28 @@ static inline void nvme_end_req(struct r blk_mq_end_request(req, status); } +static inline void nvme_end_req(struct request *req) +{ + __nvme_end_req(req, nvme_error_status(nvme_req(req)->status)); +} + +static inline void nvme_end_req_with_failover(struct request *req) +{ + u16 nvme_status = nvme_req(req)->status; + blk_status_t status = nvme_error_status(nvme_status); + + if (unlikely(nvme_status & NVME_SC_DNR)) + goto out; + + if (!blk_path_error(status)) { + pr_debug("Request meant for failover but blk_status_t (errno=%d) was not retryable.\n", + blk_status_to_errno(status)); + status = BLK_STS_IOERR; + } +out: + __nvme_end_req(req, status); +} + void nvme_complete_rq(struct request *req) { trace_nvme_complete_rq(req);
@@ -352,7 +372,10 @@ void nvme_complete_rq(struct request *re nvme_retry_req(req); return; case FAILOVER: - nvme_failover_req(req); + if (req->cmd_flags & REQ_NVME_MPATH) + nvme_failover_req(req); + else + nvme_end_req_with_failover(req); return; } }