Re: [Qemu-devel] 9pfs: unreadable dirs with random errors in guest

[M. Mohan Kumar]

Michael Tokarev <address@hidden> writes:

Hi,

Please try mounting with -oversion=9p2000.L

With qemu-1.4.0 and 9p2000.L, I could not recreate this issue. ie not
getting Unknown error during directory listing.

I am using Guest kernel 3.8.0-rc5+.

> When I mount a 9pfs filesystem in guest with no write permission for
> some dirs, I'm getting strange errors in guest.
>
> Host (as a regular user):
>  qemu-system-x86_64 -virtfs 
> local,path=/,security_model=mapped-file,mount_tag=tag
>
> Guest:
>  # mount -t 9p -o trans=virtio,ro tag /mnt
>  # ls /mnt
>  ls: reading directory /mnt: Unknown error 593
>  # ls /mnt/dev
>  ls: reading directory /mnt/dev: Unknown error 849
>  # ls /mnt/tmp
>  [works]
>  # ls /mnt/root
>  ls: cannot open directory /mnt/root: Permission denied
>
> So, it reports errors while trying to _read_ (not open)
> readable but non-writable dirs, and these errors are _random_.
> It correctly reports errors when trying to open an unreadable
> dir.
>
> This is 1.4.0.  Similar problem exists with earlier versions
> of qemu.
>
> Thanks!
>
> /mjt