[PATCH 1/9] nvme: allow timed-out ios to retry
From: Christoph Hellwig <hch@lst.de>
Date: 2017-09-18 23:14:45
Also in:
linux-nvme
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
From: James Smart <redacted> Currently the nvme_req_needs_retry() applies several checks to see if a retry is allowed. On of those is whether the current time has exceeded the start time of the io plus the timeout length. This check, if an io times out, means there is never a retry allowed for the io. Which means applications see the io failure. Remove this check and allow the io to timeout, like it does on other protocols, and retries to be made. On the FC transport, a frame can be lost for an individual io, and there may be no other errors that escalate for the connection/association. The io will timeout, which causes the transport to escalate into creating a new association, but the io that timed out, due to this retry logic, has already failed back to the application and things are hosed. Signed-off-by: James Smart <redacted> Reviewed-by: Keith Busch <redacted> Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/nvme/host/core.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d470f031e27f..5589f67d2cd8 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c@@ -134,8 +134,6 @@ static inline bool nvme_req_needs_retry(struct request *req) return false; if (nvme_req(req)->status & NVME_SC_DNR) return false; - if (jiffies - req->start_time >= req->timeout) - return false; if (nvme_req(req)->retries >= nvme_max_retries) return false; return true;
--
2.14.1