nvme-fabrics: reject I/O to offline device

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA
Link: https://gitee.com/openeuler/kernel/issues/I1WGZE



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Commands get stuck while Host NVMe-oF controller is in reconnect state.
NVMe ctrler enters into reconnect state when it loses connection with the
target. It tries to reconnect every 10 seconds
 until successful reconnection or until reconnect time-out is reached.
The default reconnect time out is 10 minutes.

Applications are expecting commands to complete with success or error
within a certain timeout (30 seconds by default).  The NVMe host is
enforcing that timeout while it is connected, never the less, during
reconnection, the timeout is not enforced and commands may get stuck for
 a long period or even forever.

To fix this long delay due to the default timeout we introduce new
session parameter "fast_io_fail_tmo". The timeout is measured in seconds
from the controller reconnect, any command beyond that timeout is
rejected. The new parameter value may be passed during 'connect'.
The default value of -1 means no timeout (similar to current behavior).

We add a new controller NVME_CTRL_FAILFAST_EXPIRED and respective
delayed work that updates the NVME_CTRL_FAILFAST_EXPIRED flag.

When the controller is entering the CONNECTING state, we schedule the
delayed_work based on failfast timeout value. If the transition is out of
CONNECTING, terminate delayed work item and ensure failfast_expired is
false. If delayed work item expires then set "NVME_CTRL_FAILFAST_EXPIRED"
flag to true.

We also update nvmf_fail_nonready_command() and
nvme_available_path() functions with check the
"NVME_CTRL_FAILFAST_EXPIRED" controller flag.

Signed-off-by: Victor Gladkov <victor.gladkov@kioxia.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chao Leng <lengchao@huawei.com>
Reviewed-by: Jike Cheng <chengjike.cheng@huawei.com>
Signed-off-by: Ruozhu Li <liruozhu@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>