On 2023-07-13 05:55, Matthew Wilcox (Oracle) wrote:
> We still need to convert to/from folios in write_begin & write_end
> to fit the API, but this removes a lot of calls to old page-based
> functions, removing many hidden calls to compound_head().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Looks good to me except one minor nit!
Reviewed-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
> @@ -624,25 +623,23 @@ affs_extent_file_ofs(struct inode *inode, u32 newsize)
> return PTR_ERR(bh);
> }
>
> -static int
> -affs_read_folio_ofs(struct file *file, struct folio *folio)
> +static int affs_read_folio_ofs(struct file *file, struct folio *folio)
> {
> - struct page *page = &folio->page;
> - struct inode *inode = page->mapping->host;
> - u32 to;
> + struct inode *inode = folio->mapping->host;
> + size_t to;
> int err;
>
> - pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
> - to = PAGE_SIZE;
> - if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) {
> - to = inode->i_size & ~PAGE_MASK;
> - memset(page_address(page) + to, 0, PAGE_SIZE - to);
> + pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, folio->index);
> + to = folio_size(folio);
> + if (folio_pos(folio) + to > inode->i_size) {
> + to = inode->i_size - folio_pos(folio);
> + folio_zero_segment(folio, to, folio_size(folio));
This change makes the code more readable!
> }
>
> - err = affs_do_readpage_ofs(page, to, 0);
> + err = affs_do_read_folio_ofs(folio, to, 0);
> if (!err)
> @@ -688,6 +686,7 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
> loff_t pos, unsigned len, unsigned copied,
> struct page *page, void *fsdata)
> {
> + struct folio *folio = page_folio(page);
> struct inode *inode = mapping->host;
> struct super_block *sb = inode->i_sb;
> struct buffer_head *bh, *prev_bh;
> @@ -701,18 +700,18 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
> to = from + len;
> /*
> * XXX: not sure if this can handle short copies (len < copied), but
> - * we don't have to, because the page should always be uptodate here,
> + * we don't have to, because the folio should always be uptodate here,
> * due to write_begin.
> */
>
> pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
> pos + len);
> bsize = AFFS_SB(sb)->s_data_blksize;
> - data = page_address(page);
> + data = folio_address(folio);
>
> bh = NULL;
> written = 0;
> - tmp = (page->index << PAGE_SHIFT) + from;
> + tmp = (folio->index << PAGE_SHIFT) + from;
Can this be made to:
tmp = folio_pos(folio) + from;
Similar to what is being done in affs_do_read_folio_ofs()
> bidx = tmp / bsize;
> boff = tmp % bsize;
> if (boff) {
> @@ -804,11 +803,11 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
> from += tmp;
> bidx++;
> }
> - SetPageUptodate(page);
> + folio_mark_uptodate(folio);
>
> done:
> affs_brelse(bh);
> - tmp = (page->index << PAGE_SHIFT) + from;
> + tmp = (folio->index << PAGE_SHIFT) + from;
Same as the previous comment.
> if (tmp > inode->i_size)
> inode->i_size = AFFS_I(inode)->mmu_private = tmp;
>
> @@ -819,8 +818,8 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
> }
>
> err_first_bh:
> - unlock_page(page);
> - put_page(page);
> + folio_unlock(folio);
> + folio_put(folio);
>
> return written;
>
