Re: [RFC PATCH 0/2] Fix up the NFS mmap code

[Al Viro]

On Fri, Jan 08, 2010 at 05:17:14PM -0800, Linus Torvalds wrote:
> 
> 
> On Fri, 8 Jan 2010, Trond Myklebust wrote:
> >
> > How about something like the following. I chose to wrap the call to
> > do_mmap_pgoff() instead of making a special ->pre_mmap(), since that
> > seems more consistent with the way we handle ->read() and ->write().
> 
> I still don't think that you can ever do mmap _and_ readdir on the same 
> inode, so there's something wrong with the lockdep annotations.

readdir() is certainly a red herring.  write(), OTOH, is quite real.
And there we do i_mutex followed by pagefaults.

I *REALLY* dislike Trond's solution, though.

Could we please get a sane expalanation of the reasons why nfs mmap
wants i_mutex in the first place?  Before we add yet another hook
from hell and complicate already overcomplicated area...
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/