Can't remove any file on guest user at latest

[zchee]

Hi @jceel and lib9p-dev, thanks for great library :)
I use lib9p for docker-machine-driver-xhyve support 9p folder share(I think you already know, thanks issue comment!).
Also, I use you wrote the xhyve side code. Thanks again.
https://github.com/zchee/docker-machine-driver-xhyve/blob/master/vendor/github.com/zchee/libhyperkit/pci_virtio_9p.c

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BTW, If I'm not wrong, I found a guest user permission(?) bug.
That can create any file, but can't remove this(or any) file, like using rm.

That occur on the latest commit of time of the found it. (not tested yet current latest)
But, not occur at 7be3e0b. (https://github.com/zchee/docker-machine-driver-xhyve/tree/master/vendor)

Sorry, I do not yet detailed debug for it. will do.
Just for reference, Here is simply reproduced way.
Note that it is only tested on the boot2docker OS built on top of docker-machine-driver-xhyve. It might be other causes.

config

• kexec:
  • -s 5,virtio-9p,host=/Users
  • https://github.com/zchee/docker-machine-driver-xhyve/blob/master/xhyve/xhyve.go#L430
• guest's mount command:
  • sudo mount -t 9p -o version=9p2000 -o trans=virtio -o uname=johndue -o dfltuid=1000 -o dfltgid=50 -o access=any host /Users
  • https://github.com/zchee/docker-machine-driver-xhyve/blob/master/xhyve/xhyve.go#L719

command on guest

dd if=/dev/zero of=/Users/johndoe/test bs=8k count=200k; rm -f /Users/johndoe/test

When create the zero filled file use dd, successful. but rm -f will fail with permission problem. This file still exists on the host.
I used config are same as you suggest variables, and xhyve side implement code is same as you folk xhyve.

Is it implements or require config has been changed? or a bug?

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Off topic and question.
lib9p seems to already support the 9P2000.u/.L protocol.
I don't yet fully understand that protocol advantages, but 9P2000 is legacy, and it might be will provide a more performance (right?)

However, If use 9P2000.u/.L, does not work dfltuid and dfltgid config on lib9p. So AFAIK, can folder share, but can't create, edit files if different to uid|gid host and guest.
Is it by design of the 9p protocol? or implementation of lib9p?

I'd appreciate if you advise to me. and sorry for long comment and poor English :(
Thanks.