Re: [PATCH] Doc fix for dget_dlock

From: Randy Dunlap
Date: Thu Aug 11 2022 - 14:33:14 EST


Hi--

On 8/11/22 07:48, Anup Parikh wrote:
> Hello Mr. Randy Dunlap,
>
> I checked include/linux/dcache.h (dget() and dget_dlock()), include/linux/lockref.h and linux/lib/lockref.c.
> My current knowledge is limited but I think:
> 1) dget_dlock() directly increments the count variable without any atomicity guards.
> 2) dget() does the same but with atomicity guarantee - even across multiple-cores on a multi-core system (according to https://stackoverflow.com/questions/36964478/understanding-synchronization-with-multiple-processors <https://stackoverflow.com/questions/36964478/understanding-synchronization-with-multiple-processors> and code in linux/lib/lockref.c).
>
> Please let me know if I should write the corresponding documentation and send a new patch.

Yes, please.
Thanks.

> Thanks and Regards,
> Anup K Parikh.
>
>
> On Tue, Aug 9, 2022 at 11:58 PM Randy Dunlap <rdunlap@xxxxxxxxxxxxx <mailto:rdunlap@xxxxxxxxxxxxx>> wrote:
>
> Hi--
>
> On 8/5/22 09:39, Anup K Parikh wrote:
> > Removes the warning for dget_dlock in include/linux/dcache.h and
> > enables generation of its API documentation
> >
> > Signed-off-by: Anup K Parikh <parikhanupk.foss@xxxxxxxxx <mailto:parikhanupk.foss@xxxxxxxxx>>
> > ---
> >  include/linux/dcache.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/linux/dcache.h b/include/linux/dcache.h
> > index f5bba5148..ce0b36f72 100644
> > --- a/include/linux/dcache.h
> > +++ b/include/linux/dcache.h
> > @@ -297,7 +297,7 @@ extern char *dentry_path(const struct dentry *, char *, int);
> >  /* Allocation counts.. */
>
> >  /**
> > - *   dget, dget_dlock -      get a reference to a dentry
> > + *   dget_dlock -    get a reference to a dentry
> >   *   @dentry: dentry to get a reference to
> >   *
> >   *   Given a dentry or %NULL pointer increment the reference count
>
> Someone was trying to document both dget() and get_dlock() with the same
> kernel-doc comment block.
> I suppose that you could duplicate the comments for dget() also.
>
> It would be nice to know the difference(s) in the functions as well.
>
> thanks.
> --
> ~Randy
>

--
~Randy