Messages in this thread | | | From | Jianchao Wang <> | Subject | [PATCH V5 0/2] nvme-pci: fix the timeout case when reset is ongoing | Date | Thu, 18 Jan 2018 18:10:00 +0800 |
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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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