Re: [PATCH 1/5] squashfs: Use a folio throughout squashfs_read_folio()

[Phillip Lougher <phillip@squashfs.org.uk>]

On 12/16/24 16:26, Matthew Wilcox (Oracle) wrote:
> Use modern folio APIs where they exist and convert back to struct
> page for the internal functions.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Phillip Lougher <phillip@squashfs.org.uk>

> ---
>   fs/squashfs/file.c | 25 +++++++++----------------
>   1 file changed, 9 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
> index 21aaa96856c1..bc6598c3a48f 100644
> --- a/fs/squashfs/file.c
> +++ b/fs/squashfs/file.c
> @@ -445,21 +445,19 @@ static int squashfs_readpage_sparse(struct page *page, int expected)
>   
>   static int squashfs_read_folio(struct file *file, struct folio *folio)
>   {
> -	struct page *page = &folio->page;
> -	struct inode *inode = page->mapping->host;
> +	struct inode *inode = folio->mapping->host;
>   	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
> -	int index = page->index >> (msblk->block_log - PAGE_SHIFT);
> +	int index = folio->index >> (msblk->block_log - PAGE_SHIFT);
>   	int file_end = i_size_read(inode) >> msblk->block_log;
>   	int expected = index == file_end ?
>   			(i_size_read(inode) & (msblk->block_size - 1)) :
>   			 msblk->block_size;
>   	int res = 0;
> -	void *pageaddr;
>   
>   	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
> -				page->index, squashfs_i(inode)->start);
> +				folio->index, squashfs_i(inode)->start);
>   
> -	if (page->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >>
> +	if (folio->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >>
>   					PAGE_SHIFT))
>   		goto out;
>   
> @@ -472,23 +470,18 @@ static int squashfs_read_folio(struct file *file, struct folio *folio)
>   			goto out;
>   
>   		if (res == 0)
> -			res = squashfs_readpage_sparse(page, expected);
> +			res = squashfs_readpage_sparse(&folio->page, expected);
>   		else
> -			res = squashfs_readpage_block(page, block, res, expected);
> +			res = squashfs_readpage_block(&folio->page, block, res, expected);
>   	} else
> -		res = squashfs_readpage_fragment(page, expected);
> +		res = squashfs_readpage_fragment(&folio->page, expected);
>   
>   	if (!res)
>   		return 0;
>   
>   out:
> -	pageaddr = kmap_atomic(page);
> -	memset(pageaddr, 0, PAGE_SIZE);
> -	kunmap_atomic(pageaddr);
> -	flush_dcache_page(page);
> -	if (res == 0)
> -		SetPageUptodate(page);
> -	unlock_page(page);
> +	folio_zero_segment(folio, 0, folio_size(folio));
> +	folio_end_read(folio, res == 0);
>   
>   	return res;
>   }