On Freitag, 17. Mai 2019 14:30:29 CEST Greg Kurz wrote: > Then, we come to the bulk problem: how to handle the case where we > have multiple devices involved in a directory we want to share ? > Antonios's proposal is a clever way to address the collisions, but > your work proves it isn't enough...
With the patch set I have right now, things finally bahave smooth. > Before going forward, I'd like > to consider another approach. > > What about: > > 1) de-compose the shared directory on a per-device basis, > ie. identify all mount points under the shared directory > > 2) expose found mount points separately, each with its onw 9p device > > 3) re-compose the directory tree within the guest using the same topology > as the host > > ie. if you want to share /vm/fs and > > /vm/fs on device A > /vm/fs/shares on device B > /vm/fs/tmp on device C > > you would start QEMU with > > -fsdev local,path=/vm/fs,id=fsdev0... \ > -device virtio-9p,fsdev=fsdev0,mount_tag=tag0 \ > -fsdev local,path=/vm/fs,id=fsdev1... \ > -device virtio-9p,fsdev=fsdev1,mount_tag=tag1 \ > -fsdev local,path=/vm/fs,id=fsdev2... \ > -device virtio-9p,fsdev=fsdev2,mount_tag=tag2 > > and /etc/fstab in the guest: > > tag0 / 9p nofail,trans=virtio,version=9p2000.L 0 0 > tag1 /shares 9p nofail,trans=virtio,version=9p2000.L 0 0 > tag2 /tmp 9p nofail,trans=virtio,version=9p2000.L 0 0 > > This involves some more work for the user but it doesn't require > any changes in QEMU. So your suggestion is actually: don't fix it. "Some" more work for the user is a quantity of how many guests you are running, multiplied by the nested virtualization levels you might have = potentially a lot of work for admins. > Would this approach solve the issues you've been hitting with Samba ? No, because that completely neglects runtime changes on a higher level (host), plus it completely destroys the fundamental idea about 9p, which is about transparency of the higher level(s). May I ask, do you have concrete reasons why you want to abondon the entire patch set? Because that's what it sounds to me. Best regards, Christian Schoenebeck
