Re: Kernel bug: Bad page state: related to generic symlink code and mmap

Al Viro
2005-08-19T19:35:45Z

On Fri, Aug 19, 2005 at 07:00:38PM +0100, Christoph Hellwig wrote:
> On Fri, Aug 19, 2005 at 07:02:18PM +0100, Al Viro wrote:
> > On Fri, Aug 19, 2005 at 05:53:32PM +0100, Al Viro wrote:
> > > I'm taking NFS helpers to libfs.c and switching ncpfs to them. IMO that's
> > > better than copying the damn thing and other network filesystems might have
> > > the same needs eventually...
> >
> > [something like this - completely untested]
> >
> > * stray_page_get_link(inode, filler) - returns ERR_PTR(error) or pointer
> > to symlink body. Said symlink body sits in a page at offset equal to
> > offsetof(page, struct stray_page_link). filler() is expected to put it
> > at such offset. Page is cached.
> >
> > * stray_page_put_link() - ->put_link() suitable for links obtained from
> > stray_page_get_link(). Unlike the usual pagecache-based variants, this
> > sucker does _not_ rely on page staying cached.
> >
> > * nfs and ncpfs switched to the helpers above.
>
> Can you add some kerneldoc comments to describe them? Especially as
> the name is not very descriptive.

Hey, if anybody has suggestions on names - they are very welcome ;-)

FWIW, I'd rather take page_symlink(), page_symlink_inode_operations,
page_put_link(), page_follow_link_light(), page_readlink(), page_getlink(),
generic_readlink() and vfs_readlink() to the same place where these guys
would live. They all belong together and none of them has any business
in fs/namei.c. Options: fs/libfs.c or separate library since fs/libfs.c
is getting crowded. Linus, do you have any objections to that or suggestions
on filename here?