Re: [PATCH 3/5] tools/kvm/9p: Don't follow symlink on server

Sasha Levin
2011-06-19T06:41:55Z

On Sun, 2011-06-19 at 10:47 +0530, Aneesh Kumar K.V wrote:
> On Sat, 18 Jun 2011 14:51:13 -0400, Sasha Levin <levinsasha928@gmail.com> wrote:
> > On Sat, 2011-06-18 at 23:19 +0530, Aneesh Kumar K.V wrote:
> > > Use lstat instead of stat
> >
> > This patch should probably come after 9p2000.u support is added, since
> > now we transparently work 'through' symlinks (because legacy 9p2000
> > doesn't support them).
> > Once 9p2000.u support is added we could represent symlinks and then a
> > switch to lstat might be due.
> >
>
> Shouldn't we aim to support 9p2000.L directly rather than supporting all
> the three versions of protocol ? Linux guest have good support for
> 9p2000.L

I'm perfectly fine with adding support directly for 9p2000.L, I just
figured that we'd need to go through the 9p2000.u milestone before
getting there instead of getting to 9p2000.L directly.

> Do you think the patch breaks any of the expectation of 9p2000 ?. It
> would be nice to get the correct file attributes when fetching
> attributes from the server, irrespective of whether client support symlink
> or not.

The idea behind following symlinks was that we could make them
transparently work even without protocol support (yes, not exactly what
the protocol defines - but it made it much more useful).

Removing symlink following also changes more than just the lstat thing,
you'd also need O_NOFOLLOW when opening files for example.

--

Sasha.