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
