Re: [Qemu-discuss] [Qemu-devel] virtfs / 9p - and "Permission denied" in guests

[Greg Kurz]

On Fri, 2 Sep 2016 13:39:05 +0100
lejeczek <address@hidden> wrote:

> hi devel, sorry to bother you but tried "users" without any 
> luck and am hoping to get some help here.
> 
> I'm trying to passthrough host's filesystem, first time but 
> a pretty regular setup, and guests mount that mount tag, I 
> can list in a guest mountpoint's content, I see files & dirs 
> but  when I try to add/create/remove content in the 
> mountpoint then it gets denied:
> 
> $ touch DDD
> touch: setting times of `DDD': No such file or directory
> 

This is strange indeed. Was the 'DDD' file already present in the directory ?

> in libvirt:
> 
>      <filesystem type='mount' accessmode='passthrough'>
>        <source 
> dir='/__.aLocalStorages/2/__.home.usersSecondHome'/>  
>        <target dir='__.x.USERs.SECOND_HOME'/>
>        <address type='pci' domain='0x0000' bus='0x00' 
> slot='0x09' function='0x0'/>
>      </filesystem>
> 

I do not use libvirt so often and I'm not sure how this gets translated
to QEMU arguments. Can you try to reproduce with QEMU directly (following
the instructions at http://wiki.qemu-project.org/Documentation/9psetup) ?
Or at least provide the QEMU command line generated by libvirt ?

> I believe I fished out all SE denials and logs are not clear 
> of any sealerts.
> I suggests "time" but time seems in sync between host and guest.

The "setting times" seems to indicate that "touch" could at least open or
create the file, but that utimensat() failed indeed... but ENOENT indicates
a problem with the file path, not the time.

> Would you have some suggestions how to troubleshoot?

Maybe you can provide the output of 'strace touch foo' where 'foo' does not 
already
exist ?

> many thanks.
> L
> 

Cheers.

--
Greg