From: Ming Lei <ming.lei@redhat.com> To: Christoph Hellwig <hch@lst.de> Cc: linux-nvme@lists.infradead.org, Xiao Liang <xiliang@redhat.com>, Ming Lei <ming.lei@redhat.com>, "jianchao.wang" <jianchao.w.wang@oracle.com>, Sagi Grimberg <sagi@grimberg.me>, Keith Busch <keith.busch@intel.com>, stable@vger.kernel.org Subject: [PATCH] nvme: don't retry request marked as NVME_REQ_CANCELLED Date: Thu, 25 Jan 2018 16:10:23 +0800 [thread overview] Message-ID: <20180125081023.13303-1-ming.lei@redhat.com> (raw) If request is marked as NVME_REQ_CANCELLED, we don't need to retry for requeuing it, and it should be completed immediately. Even simply from the flag name, it needn't to be requeued. Otherwise, it is easy to cause IO hang when IO is timed out in case of PCI NVMe: 1) IO timeout is triggered, and nvme_timeout() tries to disable device(nvme_dev_disable) and reset controller(nvme_reset_ctrl) 2) inside nvme_dev_disable(), queue is frozen and quiesced, and try to cancel every request, but the timeout request can't be canceled since it is completed by __blk_mq_complete_request() in blk_mq_rq_timed_out(). 3) this timeout req is requeued via nvme_complete_rq(), but can't be dispatched at all because queue is quiesced and hardware isn't ready, finally nvme_wait_freeze() waits for ever in nvme_reset_work(). Cc: "jianchao.wang" <jianchao.w.wang@oracle.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Keith Busch <keith.busch@intel.com> Cc: stable@vger.kernel.org Reported-by: Xiao Liang <xiliang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/nvme/host/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 0ff03cf95f7f..5cd713a164cb 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -210,6 +210,8 @@ static inline bool nvme_req_needs_retry(struct request *req) return false; if (nvme_req(req)->retries >= nvme_max_retries) return false; + if (nvme_req(req)->flags & NVME_REQ_CANCELLED) + return false; return true; } -- 2.9.5
WARNING: multiple messages have this Message-ID (diff)
From: ming.lei@redhat.com (Ming Lei) Subject: [PATCH] nvme: don't retry request marked as NVME_REQ_CANCELLED Date: Thu, 25 Jan 2018 16:10:23 +0800 [thread overview] Message-ID: <20180125081023.13303-1-ming.lei@redhat.com> (raw) If request is marked as NVME_REQ_CANCELLED, we don't need to retry for requeuing it, and it should be completed immediately. Even simply from the flag name, it needn't to be requeued. Otherwise, it is easy to cause IO hang when IO is timed out in case of PCI NVMe: 1) IO timeout is triggered, and nvme_timeout() tries to disable device(nvme_dev_disable) and reset controller(nvme_reset_ctrl) 2) inside nvme_dev_disable(), queue is frozen and quiesced, and try to cancel every request, but the timeout request can't be canceled since it is completed by __blk_mq_complete_request() in blk_mq_rq_timed_out(). 3) this timeout req is requeued via nvme_complete_rq(), but can't be dispatched at all because queue is quiesced and hardware isn't ready, finally nvme_wait_freeze() waits for ever in nvme_reset_work(). Cc: "jianchao.wang" <jianchao.w.wang at oracle.com> Cc: Sagi Grimberg <sagi at grimberg.me> Cc: Keith Busch <keith.busch at intel.com> Cc: stable at vger.kernel.org Reported-by: Xiao Liang <xiliang at redhat.com> Signed-off-by: Ming Lei <ming.lei at redhat.com> --- drivers/nvme/host/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 0ff03cf95f7f..5cd713a164cb 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -210,6 +210,8 @@ static inline bool nvme_req_needs_retry(struct request *req) return false; if (nvme_req(req)->retries >= nvme_max_retries) return false; + if (nvme_req(req)->flags & NVME_REQ_CANCELLED) + return false; return true; } -- 2.9.5
next reply other threads:[~2018-01-25 8:10 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-01-25 8:10 Ming Lei [this message] 2018-01-25 8:10 ` [PATCH] nvme: don't retry request marked as NVME_REQ_CANCELLED Ming Lei 2018-01-25 8:52 ` jianchao.wang 2018-01-25 8:52 ` jianchao.wang 2018-01-25 10:15 ` Ming Lei 2018-01-25 10:15 ` Ming Lei 2018-01-27 12:33 ` jianchao.wang 2018-01-27 12:33 ` jianchao.wang 2018-01-27 13:31 ` Ming Lei 2018-01-27 13:31 ` Ming Lei 2018-01-27 14:29 ` jianchao.wang 2018-01-27 14:29 ` jianchao.wang 2018-01-27 15:44 ` Ming Lei 2018-01-27 15:44 ` Ming Lei 2018-01-28 9:01 ` jianchao.wang 2018-01-28 9:01 ` jianchao.wang
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