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

[M. Mohan Kumar]

Michael Tokarev <address@hidden> writes:


> 28.02.2013 17:55, M. Mohan Kumar wrote:
>> 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.
>
> Yes, with 9p2000.L it works fine, both reported
> issues are gone.
>
>> I am using Guest kernel 3.8.0-rc5+.
>
> But do you see my original error, with the default mount version?
> (I'm using 3.2 guest kernel if that matters, and it is also 32bits,
> which should not matter).
Yes, with default mount option, i am getting same error.

>
>>> 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
>>