Re: nfs: infinite loop in fcntl(F_SETLKW)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sun, Apr 13, 2008 at 10:13:21AM +0200, Miklos Szeredi wrote:
> > > > > OK. So the correct fix here should really be applied to fcntl_setlk().
> > > > > There is absolutely no reason why we should be looping at all if the
> > > > > filesystem has a ->lock() method.
> > > > > 
> > > > > In fact, this looping behaviour was introduced recently in commit
> > > > > 7723ec9777d9832849b76475b1a21a2872a40d20.
> > > > 
> > > > Apologies, that was indeed a behavioral change introduced in a commit
> > > > that claimed just to be shuffling code around.
> > > 
> > > Yeah, that patch looks totally wrong.  It's not generally a good idea
> > > to do a loop where the exit condition depends on something you don't
> > > control.  And error values from filesystem methods are typically like
> > > that.  For example with fuse, the error code could come from an
> > > unprivileged userspace process.
> > > 
> > > I didn't realize this aspect of the bug previously, because I
> > > concentrated on the lockd inconsistency.
> > 
> > So, does this patch on its own fix the problem you saw?
> 
> Yes.  With the patch applied, the test program returns "lockf:
> Resource temporarily unavailable" instead of hanging.

OK, thanks!

--b.
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux