diff mbox series

[07/26] gfs2; Convert gfs2_getjdatabuf to use a folio

Message ID 20230919045135.3635437-8-willy@infradead.org
State Not Applicable
Headers show
Series Finish the create_empty_buffers() transition | expand

Commit Message

Matthew Wilcox Sept. 19, 2023, 4:51 a.m. UTC
Use the folio APIs, saving four hidden calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/gfs2/meta_io.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

Comments

Andreas Gruenbacher Sept. 19, 2023, 10:27 p.m. UTC | #1
Thanks,

but this patch has an unwanted semicolon in the subject.

On Tue, Sep 19, 2023 at 7:00 AM Matthew Wilcox (Oracle)
<willy@infradead.org> wrote:
>
> Use the folio APIs, saving four hidden calls to compound_head().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  fs/gfs2/meta_io.c | 22 ++++++++--------------
>  1 file changed, 8 insertions(+), 14 deletions(-)
>
> diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
> index f1fac1b45059..b28196015543 100644
> --- a/fs/gfs2/meta_io.c
> +++ b/fs/gfs2/meta_io.c
> @@ -400,26 +400,20 @@ static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
>  {
>         struct address_space *mapping = ip->i_inode.i_mapping;
>         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
> -       struct page *page;
> +       struct folio *folio;
>         struct buffer_head *bh;
>         unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
>         unsigned long index = blkno >> shift; /* convert block to page */
>         unsigned int bufnum = blkno - (index << shift);
>
> -       page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED);
> -       if (!page)
> -               return NULL;
> -       if (!page_has_buffers(page)) {
> -               unlock_page(page);
> -               put_page(page);
> +       folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCESSED, 0);
> +       if (IS_ERR(folio))
>                 return NULL;
> -       }
> -       /* Locate header for our buffer within our page */
> -       for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
> -               /* Do nothing */;
> -       get_bh(bh);
> -       unlock_page(page);
> -       put_page(page);
> +       bh = folio_buffers(folio);
> +       if (bh)
> +               get_nth_bh(bh, bufnum);

And we need this here:

    bh = get_nth_bh(bh, bufnum);

> +       folio_unlock(folio);
> +       folio_put(folio);
>         return bh;
>  }
>
> --
> 2.40.1
>
>

Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Matthew Wilcox Sept. 20, 2023, 3:11 a.m. UTC | #2
On Wed, Sep 20, 2023 at 12:27:08AM +0200, Andreas Gruenbacher wrote:
> Thanks,
> 
> but this patch has an unwanted semicolon in the subject.

Thanks.  My laptop has a dodgy shift key, so this sometimes happens.
The build quality on HP Spectre laptops has gone downhill in the last
few years.

> > -       page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED);
> > -       if (!page)
> > -               return NULL;
> > -       if (!page_has_buffers(page)) {
> > -               unlock_page(page);
> > -               put_page(page);
> > +       folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCESSED, 0);
> > +       if (IS_ERR(folio))
> >                 return NULL;
> > -       }
> > -       /* Locate header for our buffer within our page */
> > -       for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
> > -               /* Do nothing */;
> > -       get_bh(bh);
> > -       unlock_page(page);
> > -       put_page(page);
> > +       bh = folio_buffers(folio);
> > +       if (bh)
> > +               get_nth_bh(bh, bufnum);
> 
> And we need this here:
> 
>     bh = get_nth_bh(bh, bufnum);

Oof.  I should make that __must_check so the compiler tells me I'm being
an idiot.

Thanks!
diff mbox series

Patch

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index f1fac1b45059..b28196015543 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -400,26 +400,20 @@  static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
 {
 	struct address_space *mapping = ip->i_inode.i_mapping;
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	struct page *page;
+	struct folio *folio;
 	struct buffer_head *bh;
 	unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 	unsigned long index = blkno >> shift; /* convert block to page */
 	unsigned int bufnum = blkno - (index << shift);
 
-	page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED);
-	if (!page)
-		return NULL;
-	if (!page_has_buffers(page)) {
-		unlock_page(page);
-		put_page(page);
+	folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCESSED, 0);
+	if (IS_ERR(folio))
 		return NULL;
-	}
-	/* Locate header for our buffer within our page */
-	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
-		/* Do nothing */;
-	get_bh(bh);
-	unlock_page(page);
-	put_page(page);
+	bh = folio_buffers(folio);
+	if (bh)
+		get_nth_bh(bh, bufnum);
+	folio_unlock(folio);
+	folio_put(folio);
 	return bh;
 }