Re: [Qemu-devel] 9pfs segfaults on chmod(special)

[Michael Tokarev]

28.02.2013 16:24, M. Mohan Kumar wrote:
> Michael Tokarev <address@hidden> writes:
>> 28.02.2013 13:12, Aneesh Kumar K.V wrote:

>>> any specific reason why you are trying 9p .u ?
>>
>> Sorry?  What _is_ "9p .u" ? :)
> 
> 9p.u is the extension of 9p protocol developed during Linux porting of
> 9p. Original 9p was designed for Plan 9 operating system. 9p.u has
> support for numerical uids, gids, additional mode and permissio bits.
> 
> But still 9p.u lacked support for full Linux VFS operations. Such as
> xattrs, locking etc. In order to overcome these issues and address
> functionalities provides by Linux VFS a new protocol 9p2000.L was
> developed (http://code.google.com/p/diod/wiki/protocol)
> 
> By default 9p.u is used, you can override by that
>  mount -t 9p -otrans=virtio,version=9p2000.L tag /mnt

Aha.  Well. Most likely the reason is
 a) the default is "wrong" and
 b) there's not much knowledge about even existance of other option.

I've got this report from someone else (a debian user) and am just
forwarding it here (after verifying and adding a backtrace etc), --
this is the first time I _ever_ used 9pfs ;)

The same probably applies to the other bug (random errors for
unwritable dirs -- note the subject was wrong, it is about
unWRITEable dirs, not unreadable).

So it looks like the default mode isn't being tested much,
and when the usage is "real", everyone is using the .L mode.
Still, I think, it'd be nice to fix things in the default
mode too ;)

Thank you!

/mjt