[PATCH 2/4] nvme: refactor command completion
Christoph Hellwig
hch at lst.de
Mon Aug 17 04:15:42 EDT 2020
Lift all the code to decide the dispostition of a completed command
from nvme_complete_rq and nvme_failover_req into a new helper, which
returns an emum of the potential actions. nvme_complete_rq then
just switches on those and calls the proper helper for the action.
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
drivers/nvme/host/core.c | 76 ++++++++++++++++++++++-------------
drivers/nvme/host/multipath.c | 47 ++++++----------------
drivers/nvme/host/nvme.h | 31 ++++++++++++--
3 files changed, 90 insertions(+), 64 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 88cff309d8e4f0..8d474adad721fb 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -241,17 +241,6 @@ static blk_status_t nvme_error_status(u16 status)
}
}
-static inline bool nvme_req_needs_retry(struct request *req)
-{
- if (blk_noretry_request(req))
- return false;
- if (nvme_req(req)->status & NVME_SC_DNR)
- return false;
- if (nvme_req(req)->retries >= nvme_max_retries)
- return false;
- return true;
-}
-
static void nvme_retry_req(struct request *req)
{
struct nvme_ns *ns = req->q->queuedata;
@@ -268,34 +257,67 @@ static void nvme_retry_req(struct request *req)
blk_mq_delay_kick_requeue_list(req->q, delay);
}
-void nvme_complete_rq(struct request *req)
+enum nvme_disposition {
+ COMPLETE,
+ RETRY,
+ FAILOVER,
+};
+
+static inline enum nvme_disposition nvme_decide_disposition(struct request *req)
{
- blk_status_t status = nvme_error_status(nvme_req(req)->status);
+ u16 status = nvme_req(req)->status & 0x7ff;
- trace_nvme_complete_rq(req);
+ if (likely(status == 0))
+ return COMPLETE;
- nvme_cleanup_cmd(req);
+ if (blk_noretry_request(req) || (status & NVME_SC_DNR) ||
+ nvme_req(req)->retries >= nvme_max_retries)
+ return COMPLETE;
- if (nvme_req(req)->ctrl->kas)
- nvme_req(req)->ctrl->comp_seen = true;
+ if (req->cmd_flags & REQ_NVME_MPATH) {
+ if (nvme_is_path_error(status))
+ return FAILOVER;
+ }
- if (unlikely(status != BLK_STS_OK && nvme_req_needs_retry(req))) {
- if ((req->cmd_flags & REQ_NVME_MPATH) && nvme_failover_req(req))
- return;
+ if (blk_queue_dying(req->q))
+ return COMPLETE;
- if (!blk_queue_dying(req->q)) {
- nvme_retry_req(req);
- return;
- }
- } else if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
- req_op(req) == REQ_OP_ZONE_APPEND) {
+ return RETRY;
+}
+
+static inline void nvme_end_req(struct request *req)
+{
+ 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,
le64_to_cpu(nvme_req(req)->result.u64));
- }
nvme_trace_bio_complete(req, status);
blk_mq_end_request(req, status);
}
+
+void nvme_complete_rq(struct request *req)
+{
+ trace_nvme_complete_rq(req);
+ nvme_cleanup_cmd(req);
+
+ if (nvme_req(req)->ctrl->kas)
+ nvme_req(req)->ctrl->comp_seen = true;
+
+ switch (nvme_decide_disposition(req)) {
+ case COMPLETE:
+ nvme_end_req(req);
+ return;
+ case RETRY:
+ nvme_retry_req(req);
+ return;
+ case FAILOVER:
+ nvme_failover_req(req);
+ return;
+ }
+}
EXPORT_SYMBOL_GPL(nvme_complete_rq);
bool nvme_cancel_request(struct request *req, void *data, bool reserved)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 3ded54d2c9c6ad..abc5bcf7209506 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -65,51 +65,30 @@ void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
}
}
-bool nvme_failover_req(struct request *req)
+void nvme_failover_req(struct request *req)
{
struct nvme_ns *ns = req->q->queuedata;
- u16 status = nvme_req(req)->status;
+ u16 status = nvme_req(req)->status & 0x7ff;
unsigned long flags;
- switch (status & 0x7ff) {
- case NVME_SC_ANA_TRANSITION:
- case NVME_SC_ANA_INACCESSIBLE:
- case NVME_SC_ANA_PERSISTENT_LOSS:
- /*
- * If we got back an ANA error we know the controller is alive,
- * but not ready to serve this namespaces. The spec suggests
- * we should update our general state here, but due to the fact
- * that the admin and I/O queues are not serialized that is
- * fundamentally racy. So instead just clear the current path,
- * mark the the path as pending and kick of a re-read of the ANA
- * log page ASAP.
- */
- nvme_mpath_clear_current_path(ns);
- if (ns->ctrl->ana_log_buf) {
- set_bit(NVME_NS_ANA_PENDING, &ns->flags);
- queue_work(nvme_wq, &ns->ctrl->ana_work);
- }
- break;
- case NVME_SC_HOST_PATH_ERROR:
- case NVME_SC_HOST_ABORTED_CMD:
- /*
- * Temporary transport disruption in talking to the controller.
- * Try to send on a new path.
- */
- nvme_mpath_clear_current_path(ns);
- break;
- default:
- /* This was a non-ANA error so follow the normal error path. */
- return false;
+ nvme_mpath_clear_current_path(ns);
+
+ /*
+ * If we got back an ANA error, we know the controller is alive but not
+ * ready to serve this namespace. Kick of a re-read of the ANA
+ * information page, and just try any other available path for now.
+ */
+ if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) {
+ set_bit(NVME_NS_ANA_PENDING, &ns->flags);
+ queue_work(nvme_wq, &ns->ctrl->ana_work);
}
spin_lock_irqsave(&ns->head->requeue_lock, flags);
blk_steal_bios(&ns->head->requeue_list, req);
spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
- blk_mq_end_request(req, 0);
+ blk_mq_end_request(req, 0);
kblockd_schedule_work(&ns->head->requeue_work);
- return true;
}
void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 6d69cc7306d034..dfcdeb318f3ab6 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -523,6 +523,32 @@ static inline u32 nvme_bytes_to_numd(size_t len)
return (len >> 2) - 1;
}
+static inline bool nvme_is_ana_error(u16 status)
+{
+ switch (status & 0x7ff) {
+ case NVME_SC_ANA_TRANSITION:
+ case NVME_SC_ANA_INACCESSIBLE:
+ case NVME_SC_ANA_PERSISTENT_LOSS:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static inline bool nvme_is_path_error(u16 status)
+{
+ switch (status & 0x7ff) {
+ case NVME_SC_HOST_PATH_ERROR:
+ case NVME_SC_HOST_ABORTED_CMD:
+ case NVME_SC_ANA_TRANSITION:
+ case NVME_SC_ANA_INACCESSIBLE:
+ case NVME_SC_ANA_PERSISTENT_LOSS:
+ return true;
+ default:
+ return false;
+ }
+}
+
/*
* Fill in the status and result information from the CQE, and then figure
* out if we blk-mq will need to use IPI magic to complete the request, and
@@ -635,7 +661,7 @@ void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys);
void nvme_mpath_start_freeze(struct nvme_subsystem *subsys);
void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
struct nvme_ctrl *ctrl, int *flags);
-bool nvme_failover_req(struct request *req);
+void nvme_failover_req(struct request *req);
void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head);
void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id);
@@ -694,9 +720,8 @@ static inline void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
}
-static inline bool nvme_failover_req(struct request *req)
+static inline void nvme_failover_req(struct request *req)
{
- return false;
}
static inline void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
{
--
2.28.0
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