Connection reset in nvme-cli?

[Hannes Reinecke <hare@suse.de>]

Hey Sagi,

the secure-concatenation stuff is nearing completion, but there is just
one snag: After DH-CHAP negotiation the connection has to be reset to
start over with a TLS-encrypted connection.

IE currently I have to do:

nvme connect ...
echo 1 > /sys/class/nvme/nvmeX/reset_controller

which is clearly unsatisfactory.

So now I have two options:
1) reset the controller after the call to ->create_ctrl()
    in drivers/nvme/host/fabrics.c
2) reset the controller from nvme-cli after the connection
    was established.
The really awkward thing is that resetting the connection works
when run from the error recovery; it's just the initial connect
for which I need to do something 'special'.

Personally, I'm not a big fan of option 2), as it means that we
have to do a 'blind' reset, ie we have to assume that upon reset
we'll pick up the correct key. If someone slips in a new key
after the initial connect and the reset call the connection will
fail as we won't be able to pick up the correct key.
Option 1) doesn't have this problem (as the 'options' structure
is carried over across resets, and the generated key is stored
in there). But then the intention seems to be to move error handling
/ retries from the initial connect over to userspace.

So, which way do you prefer?

Cheers,

Hannes