Re: Use of disowned struct filename after 3c5499fa56f5?

[Dmitry Kadashev <dkadashev@gmail.com>]

On Fri, Nov 06, 2020 at 01:27:51PM +0000, Pavel Begunkov wrote:
> On 06/11/2020 13:15, Dmitry Kadashev wrote:
> > On Fri, Nov 06, 2020 at 12:49:05PM +0000, Pavel Begunkov wrote:
> >> On 06/11/2020 10:08, Dmitry Kadashev wrote:
> >>> On Thu, Nov 05, 2020 at 08:57:43PM +0000, Pavel Begunkov wrote:
> >>> That's pretty much what do_unlinkat() does btw. Thanks Pavel for looking
> >>> into this!
> >>>
> >>> Can I pick your brain some more? do_mkdirat() case is slightly
> >>> different:
> >>>
> >>> static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
> >>> {
> >>> 	struct dentry *dentry;
> >>> 	struct path path;
> >>> 	int error;
> >>> 	unsigned int lookup_flags = LOOKUP_DIRECTORY;
> >>>
> >>> retry:
> >>> 	dentry = user_path_create(dfd, pathname, &path, lookup_flags);
> >>>
> >>> If we just change @pathname to struct filename, then user_path_create
> >>> can be swapped for filename_create(). But the same problem on retry
> >>> arises. Is there some more or less "idiomatic" way to solve this?
> >>
> >> I don't think there is, fs guys may have a different opinion but
> >> sometimes it's hard to get through them.
> >>
> >> I'd take a filename reference before "retry:"
> > 
> > How do I do that? Just `++name.refcnt` or is there a helper function /
> > better way?
> 
> I don't know, take a look around if there is one. In the end, a review and
> guys familiar with this code will hopefully suggest a better way (if any).

OK, thanks Pavel! I'll look around.

-- 
Dmitry