tree 3f1e2e131beda1e027bf568cff77e2ebb0b0db1e
parent 9b00deb26b4cd03bc1e33afe7a5e2c5e0e87f06c
author Jeremy Kerr <jk@ozlabs.org> 1533870989 +0800
committer Jeremy Kerr <jk@ozlabs.org> 1533876287 +0800

nbd-proxy: listen for udev change event before running start hook

Currently, we run the start state-change hook as soon as the nbd session
has been established. However, at that point the nbd device isn't
connected, as we haven't processed any read/write operations on the
block device.

This change defers running the start script until we know that the
device is initialised - when we see a udev change event occur. To do
this, we establish a udev monitor.

Once we see that state change, we run the state change hooks and shut
down the udev monitor.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>