From 150dfb6c834c9e0e92db7794530b09fd2b9f05c8 Mon Sep 17 00:00:00 2001 From: Chaitanya Kulkarni Date: Tue, 20 Oct 2020 16:14:04 -0700 Subject: [PATCH] nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit By default, we set the passthru request allocation flag such that it returns the error in the following code path and we fail the I/O when BLK_MQ_REQ_NOWAIT is used for request allocation :- nvme_alloc_request()  blk_mq_alloc_request()   blk_mq_queue_enter()    if (flag & BLK_MQ_REQ_NOWAIT)         return -EBUSY; <-- return if busy. On some controllers using BLK_MQ_REQ_NOWAIT ends up in I/O error where the controller is perfectly healthy and not in a degraded state. Block layer request allocation does allow us to wait instead of immediately returning the error when we BLK_MQ_REQ_NOWAIT flag is not used. This has shown to fix the I/O error problem reported under heavy random write workload. Remove the BLK_MQ_REQ_NOWAIT parameter for passthru request allocation which resolves this issue. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Logan Gunthorpe Signed-off-by: Christoph Hellwig --- drivers/nvme/target/passthru.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c index 0814cba8298a..8ee94f056898 100644 --- a/drivers/nvme/target/passthru.c +++ b/drivers/nvme/target/passthru.c @@ -244,7 +244,7 @@ static void nvmet_passthru_execute_cmd(struct nvmet_req *req) q = ns->queue; } - rq = nvme_alloc_request(q, req->cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY); + rq = nvme_alloc_request(q, req->cmd, 0, NVME_QID_ANY); if (IS_ERR(rq)) { status = NVME_SC_INTERNAL; goto out_put_ns; -- 2.11.0