Messages in this thread | | | Subject | Re: [PATCH V2 0/6]nvme-pci: fixes on nvme_timeout and nvme_dev_disable | From | "jianchao.wang" <> | Date | Fri, 9 Feb 2018 09:50:58 +0800 |
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Hi Keith and Sagi
Many thanks for your kindly response. That's really appreciated.
On 02/09/2018 01:56 AM, Keith Busch wrote: > On Thu, Feb 08, 2018 at 05:56:49PM +0200, Sagi Grimberg wrote: >> Given the discussion on this set, you plan to respin again >> for 4.16? > > With the exception of maybe patch 1, this needs more consideration than > I'd feel okay with for the 4.16 release. > Currently, one of the block is the nvme_wait_freeze in nvme_reset_work. This cause some issues when I test this patchset yesterday. As I posted on the V1 patchset mail thread:
if we set NVME_REQ_CANCELLED and return BLK_EH_HANDLED as the RESETTING case, nvme_reset_work will hang forever, because no one could complete the entered requests.
if we invoke nvme_reset_ctrl after modify the state machine to be able to change to RESETTING to RECONNECTING and queue reset_work, we still cannot move things forward, because the reset_work is being executed.
if we use nvme_wait_freeze_timeout in nvme_reset_work, unfreeze and return if expires. But the timeout value is tricky..
And actually, one of the possible solution to fix this cleanly is blk_set_preempt_only. It is a lightweight way to gate the new bios out of generic_make_request.
Looking forward your advice on this. And many thanks for your precious time on this.
Sincerely Thanks Jianchao
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