[PATCH] nvme: Let the blocklayer set timeouts for requests

[Heyne, Maximilian]

When initializing an nvme request which is about to be send to the block
layer, we do not need to initialize its timeout. If it's left
uninitialized at 0 the block layer will use the request queue's timeout
in blk_add_timer (via nvme_start_request which is called from
nvme_*_queue_rq). These timeouts are setup to either NVME_IO_TIMEOUT or
NVME_ADMIN_TIMEOUT when the request queues were created.

Because the io_timeout of the IO queues can actually be modified via
sysfs, the following situation can occur:

1) NVME_IO_TIMEOUT = 30 (default module parameter)
2) nvme1n1 is probed. IO queues default timeout is 30 s
3) manually change the IO timeout to 90 s
   echo 90000 > /sys/class/nvme/nvme1/nvme1n1/queue/io_timeout
4) nvme zns report-zones /dev/nvme1n1
   This command issues IO commands with timeout 30 s instead of the
   wanted 90 s which might be more suitable for this device.

This patch, therefore, improves the consistency of IO timeout usage.
However, there are still uses of NVME_IO_TIMEOUT which could be
inconsistent with what is set in the device's request_queue by the user.

Signed-off-by: Maximilian Heyne <mheyne at amazon.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 f1f719351f3f2..3a6d74e6dae11 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -724,10 +724,8 @@ void nvme_init_request(struct request *req, struct nvme_command *cmd)
 		struct nvme_ns *ns = req->q->disk->private_data;
 
 		logging_enabled = ns->head->passthru_err_log_enabled;
-		req->timeout = NVME_IO_TIMEOUT;
 	} else { /* no queuedata implies admin queue */
 		logging_enabled = nr->ctrl->passthru_err_log_enabled;
-		req->timeout = NVME_ADMIN_TIMEOUT;
 	}
 
 	if (!logging_enabled)
-- 
2.47.3




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