A crash happens when trying to disconnect a reconnecting ctrl:
1) The network was cut off when the connection was just established,
scan work hang there waiting for some IOs complete. Those I/Os were
retried because we return BLK_STS_RESOURCE to blk in reconnecting.
2) After a while, I tried to disconnect this connection. This
procedure also hangs because it tried to obtain ctrl->scan_lock.
It should be noted that now we have switched the controller state
to NVME_CTRL_DELETING.
3) In nvme_check_ready(), we always return true when ctrl->state is
NVME_CTRL_DELETING, so those retrying I/Os were issued to the bottom
device which was already freed.
To fix this, when ctrl->state is NVME_CTRL_DELETING, issue cmd to bottom
device only when queue state is live. If not, return host path error to
the block layer
Signed-off-by: Ruozhu Li <liruozhu@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>