[PATCH V5 0/9] nvme: pci: fix & improve timeout handling

[ming.lei@redhat.com (Ming Lei)]

Hi,

The 1st patch introduces blk_quiesce_timeout() and blk_unquiesce_timeout()
for NVMe, meantime fixes blk_sync_queue().

The 2nd patch covers timeout for admin commands for recovering controller
for avoiding possible deadlock.

The 3rd and 4th patches avoid to wait_freeze on queues which aren't frozen.

The last 5 patches fixes several races wrt. NVMe timeout handler, and
finally can make blktests block/011 passed. Meantime the NVMe PCI timeout
mecanism become much more rebost than before.

gitweb:
	https://github.com/ming1/linux/commits/v4.17-rc-nvme-timeout.V5

V5:
	- avoid to remove controller in case of reset failure in inner EHs
	- make sure that nvme_unfreeze and nvme_start_freeze are paired

V4:
	- fixe nvme_init_set_host_mem_cmd()
	- use nested EH model, and run both nvme_dev_disable() and
	resetting in one same context

V3:
	- fix one new race related freezing in patch 4, nvme_reset_work()
	may hang forever without this patch
	- rewrite the last 3 patches, and avoid to break nvme_reset_ctrl*()

V2:
	- fix draining timeout work, so no need to change return value from
	.timeout()
	- fix race between nvme_start_freeze() and nvme_unfreeze()
	- cover timeout for admin commands running in EH

Ming Lei (9):
  block: introduce blk_quiesce_timeout() and blk_unquiesce_timeout()
  nvme: pci: cover timeout for admin commands running in EH
  nvme: pci: only wait freezing if queue is frozen
  nvme: pci: freeze queue in nvme_dev_disable() in case of error
    recovery
  nvme: pci: prepare for supporting error recovery from resetting
    context
  nvme: pci: move error handling out of nvme_reset_dev()
  nvme: pci: don't unfreeze queue until controller state updating
    succeeds
  nvme: core: introduce nvme_force_change_ctrl_state()
  nvme: pci: support nested EH

 block/blk-core.c         |  21 ++-
 block/blk-mq.c           |   9 ++
 block/blk-timeout.c      |   5 +-
 drivers/nvme/host/core.c |  57 +++++++
 drivers/nvme/host/nvme.h |   7 +
 drivers/nvme/host/pci.c  | 402 +++++++++++++++++++++++++++++++++++++++++------
 include/linux/blkdev.h   |  13 ++
 7 files changed, 462 insertions(+), 52 deletions(-)

Cc: James Smart <james.smart at broadcom.com>
Cc: Jianchao Wang <jianchao.w.wang at oracle.com>
Cc: Christoph Hellwig <hch at lst.de>
Cc: Sagi Grimberg <sagi at grimberg.me>
Cc: linux-nvme at lists.infradead.org
Cc: Laurence Oberman <loberman at redhat.com>
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