Re: [PATCH v5 1/2] fs/dcache: add d_compare() helper support

[Xiubo Li]

On 5/24/22 1:57 AM, Luis Chamberlain wrote:
> On Thu, May 19, 2022 at 06:18:45PM +0800, Xiubo Li wrote:
> > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
> > ---
> >   fs/dcache.c            | 15 +++++++++++++++
> >   include/linux/dcache.h |  2 ++
> >   2 files changed, 17 insertions(+)
> >
> > diff --git a/fs/dcache.c b/fs/dcache.c
> > index 93f4f5ee07bf..95a72f92a94b 100644
> > --- a/fs/dcache.c
> > +++ b/fs/dcache.c
> > @@ -2262,6 +2262,21 @@ static inline bool d_same_name(const struct dentry *dentry,
> >   				       name) == 0;
> >   }
> >   
> > +/**
> > + * d_compare - compare dentry name with case-exact name
> > + * @parent: parent dentry
> > + * @dentry: the negative dentry that was passed to the parent's lookup func
> > + * @name:   the case-exact name to be associated with the returned dentry
> > + *
> > + * Return: 0 if names are same, or 1
> > + */
> > +bool d_compare(const struct dentry *parent, const struct dentry *dentry,
> > +	       const struct qstr *name)
> > +{
> > +	return !d_same_name(dentry, parent, name);
> What's wrong with d_same_name()? Why introduce a whole new operation
> and export it when you the same prototype except first and second
> argument moved with an even more confusing name?

Sounds resonable, will export the d_same_name instead.

> > +}
> > +EXPORT_SYMBOL(d_compare);
> New symbols should go with EXPORT_SYMBOL_GPL() instead.

Not familiar with the story about this, before I checked the Doc and 
didn't find any where says we must use it and just followed what recent 
commits did.

If this is what we should use I will switch to it in the next version.

Thanks

-- Xiubo


>    Luis