Messages in this thread | | | Subject | Re: [PATCH V5 0/2] nvme-pci: fix the timeout case when reset is ongoing | From | James Smart <> | Date | Thu, 18 Jan 2018 07:34:59 -0800 |
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Jianchao,
This looks very coherent to me. Thank You.
-- james
On 1/18/2018 2:10 AM, Jianchao Wang wrote: > Hello > > Please consider the following scenario. > nvme_reset_ctrl > -> set state to RESETTING > -> queue reset_work > (scheduling) > nvme_reset_work > -> nvme_dev_disable > -> quiesce queues > -> nvme_cancel_request > on outstanding requests > -------------------------------_boundary_ > -> nvme initializing (issue request on adminq) > > Before the _boundary_, not only quiesce the queues, but only cancel > all the outstanding requests. > > A request could expire when the ctrl state is RESETTING. > - If the timeout occur before the _boundary_, the expired requests > are from the previous work. > - Otherwise, the expired requests are from the controller initializing > procedure, such as sending cq/sq create commands to adminq to setup > io queues. > In current implementation, nvme_timeout cannot identify the _boundary_ > so only handles second case above. > > In fact, after Sagi's commit (nvme-rdma: fix concurrent reset and > reconnect), both nvme-fc/rdma have following pattern: > RESETTING - quiesce blk-mq queues, teardown and delete queues/ > connections, clear out outstanding IO requests... > RECONNECTING - establish new queues/connections and some other > initializing things. > Introduce RECONNECTING to nvme-pci transport to do the same mark > Then we get a coherent state definition among nvme pci/rdma/fc > transports and nvme_timeout could identify the _boundary_. > > V5: > - discard RESET_PREPARE and introduce RESETTING into nvme-pci > - change the 1st patch's name and comment > - other misc changes > > V4: > - rebase patches on Jens' for-next > - let RESETTING equal to RECONNECTING in terms of work procedure > - change the 1st patch's name and comment > - other misc changes > > V3: > - fix wrong reference in loop.c > - other misc changes > > V2: > - split NVME_CTRL_RESETTING into NVME_CTRL_RESET_PREPARE and > NVME_CTRL_RESETTING. Introduce new patch based on this. > - distinguish the requests based on the new state in nvme_timeout > - change comments of patch > > drivers/nvme/host/core.c | 2 +- > drivers/nvme/host/pci.c | 43 ++++++++++++++++++++++++++++++++----------- > 2 files changed, 33 insertions(+), 12 deletions(-) > > Thanks > Jianchao
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