Re: [PATCH 3/3] gfs2: Convert stuffed_readpage() to stuffed_read_folio()

Andreas Gruenbacher
2023-11-09T21:53:47Z

On Tue, Nov 7, 2023 at 10:27 PM Matthew Wilcox (Oracle)
<willy@infradead.org> wrote:
> Use folio_fill_tail() to implement the unstuffing and folio_end_read()
> to simultaneously mark the folio uptodate and unlock it. Unifies a
> couple of code paths.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> fs/gfs2/aops.c | 37 +++++++++++++++++--------------------
> 1 file changed, 17 insertions(+), 20 deletions(-)
>
> diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
> index 9611bfceda4b..ba8742dc91f8 100644
> --- a/fs/gfs2/aops.c
> +++ b/fs/gfs2/aops.c
> @@ -403,18 +403,18 @@ static int gfs2_jdata_writepages(struct address_space *mapping,
> }
>
> /**
> - * stuffed_readpage - Fill in a Linux folio with stuffed file data
> + * stuffed_read_folio - Fill in a Linux folio with stuffed file data
> * @ip: the inode
> * @folio: the folio
> *
> * Returns: errno
> */
> -static int stuffed_readpage(struct gfs2_inode *ip, struct folio *folio)
> +static int stuffed_read_folio(struct gfs2_inode *ip, struct folio *folio)
> {
> - struct buffer_head *dibh;
> - size_t i_size = i_size_read(&ip->i_inode);
> - void *data;
> - int error;
> + struct buffer_head *dibh = NULL;
> + size_t dsize = i_size_read(&ip->i_inode);
> + void *from = NULL;
> + int error = 0;
>
> /*
> * Due to the order of unstuffing files and ->fault(), we can be
> @@ -422,22 +422,20 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct folio *folio)
> * so we need to supply one here. It doesn't happen often.
> */
> if (unlikely(folio->index)) {
> - folio_zero_range(folio, 0, folio_size(folio));
> - folio_mark_uptodate(folio);
> - return 0;
> + dsize = 0;
> + } else {
> + error = gfs2_meta_inode_buffer(ip, &dibh);
> + if (error)
> + goto out;
> + from = dibh->b_data + sizeof(struct gfs2_dinode);
> }
>
> - error = gfs2_meta_inode_buffer(ip, &dibh);
> - if (error)
> - return error;
> -
> - data = dibh->b_data + sizeof(struct gfs2_dinode);
> - memcpy_to_folio(folio, 0, data, i_size);
> - folio_zero_range(folio, i_size, folio_size(folio) - i_size);
> + folio_fill_tail(folio, 0, from, dsize);
> brelse(dibh);
> - folio_mark_uptodate(folio);
> +out:
> + folio_end_read(folio, error == 0);
>
> - return 0;
> + return error;
> }
>
> /**
> @@ -456,8 +454,7 @@ static int gfs2_read_folio(struct file *file, struct folio *folio)
> (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
> error = iomap_read_folio(folio, &gfs2_iomap_ops);
> } else if (gfs2_is_stuffed(ip)) {
> - error = stuffed_readpage(ip, folio);
> - folio_unlock(folio);
> + error = stuffed_read_folio(ip, folio);
> } else {
> error = mpage_read_folio(folio, gfs2_block_map);
> }
> --
> 2.42.0
>

Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

Thanks,
Andreas