Re: [PATCH v2 2/4] fs/sysv: Change the signature of dir_get_page()

Fabio M. De Francesco
2023-01-12T20:47:31Z

On mercoledì 11 gennaio 2023 03:34:47 CET Al Viro wrote:
> On Mon, Jan 09, 2023 at 06:06:37PM +0100, Fabio M. De Francesco wrote:
> > -struct sysv_dir_entry * sysv_dotdot (struct inode *dir, struct page **p)
> > +struct sysv_dir_entry *sysv_dotdot(struct inode *dir, struct page **p)
> >
> > {
> >
> > - struct page *page = dir_get_page(dir, 0);
> > - struct sysv_dir_entry *de = NULL;
> > + struct page *page = NULL;
> > + struct sysv_dir_entry *de = dir_get_page(dir, 0, &page);
> >
> > - if (!IS_ERR(page)) {
> > - de = (struct sysv_dir_entry*) page_address(page) + 1;
> > + if (!IS_ERR(de)) {
> >
> > *p = page;
> >
> > + return (struct sysv_dir_entry *)page_address(page) + 1;
> >
> > }
> >
> > - return de;
> > + return NULL;
> >
> > }
>
> Would be better off with
>
> struct sysv_dir_entry *de = dir_get_page(dir, 0, p);
>
> if (!IS_ERR(de))
> return de + 1; // ".." is the second directory entry
> return NULL;
>
> IMO...

I totally agree with you...

1) This comment is a good way to explain why we return "de + 1".
2) "*p = page" is redundant, so it's not necessary because we assign the out
argument in dir_get_page() if and only if read_mapping_page() doesn't fail.

I will send v3 asap.

Thanks for your suggestions.

Fabio