Re: [libvirt] [RFC v2 0/4] LXC with block device and enabled userns
On Wed, Jun 13, 2018 at 03:18:02PM +0100, Radostin Stoyanov wrote:
> Ideally qemu-nbd would automatically exit when the last use of
/dev/nbdNNN
> was release (ie when filesystem was unmounted). This is something you can
> enable for loopback devices, but I'm not sure it works for NBD. THis would
> be a useful kernel enhancement if someone feels adventurous.
It seems like qemu-nbd terminates automatically when the last client
disconnects.
Right, but in the case where the kernel has connected qemu-nbd to a block
device, the kernel itself is a client that won't exit.
So what I was describing was that the kernel should automatically delete
the /dev/ndb0 device when the last mount was unmounted, and thus in turn
it can close the last client of qemu-nbd
https://git.qemu.org/?p=qemu.git;a=blob;f=qemu-nbd.c;h=51b9d38c72732c821c...
I will send a patch thattakes qemu-nbd out of the cgroups and
disconnects qemu-nbd on container shutdown.
Radostin
Regards,
Daniel
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