Re: [PATCH 17/23] ocfs2: Convert ocfs2_duplicate_clusters_by_page() to use a folio

[Joseph Qi <joseph.qi@linux.alibaba.com>]

On 2024/12/6 01:16, Matthew Wilcox (Oracle) wrote:
> From: Mark Tinguely <mark.tinguely@oracle.com>
> 
> Retrieve folios from the page cache, not pages, and use a folio
> throughout this function.  Removes seven calls to compound_head().
> 
> Signed-off-by: Mark Tinguely <mark.tinguely@oracle.com>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Looks good.
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

> ---
>  fs/ocfs2/refcounttree.c | 32 +++++++++++++++-----------------
>  1 file changed, 15 insertions(+), 17 deletions(-)
> 
> diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
> index 004393b13c0a..68e0339690e9 100644
> --- a/fs/ocfs2/refcounttree.c
> +++ b/fs/ocfs2/refcounttree.c
> @@ -2902,7 +2902,6 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  	int ret = 0, partial;
>  	struct super_block *sb = inode->i_sb;
>  	u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
> -	struct page *page;
>  	pgoff_t page_index;
>  	unsigned int from, to;
>  	loff_t offset, end, map_end;
> @@ -2921,6 +2920,7 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  		end = i_size_read(inode);
>  
>  	while (offset < end) {
> +		struct folio *folio;
>  		page_index = offset >> PAGE_SHIFT;
>  		map_end = ((loff_t)page_index + 1) << PAGE_SHIFT;
>  		if (map_end > end)
> @@ -2933,9 +2933,10 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  			to = map_end & (PAGE_SIZE - 1);
>  
>  retry:
> -		page = find_or_create_page(mapping, page_index, GFP_NOFS);
> -		if (!page) {
> -			ret = -ENOMEM;
> +		folio = __filemap_get_folio(mapping, page_index,
> +				FGP_LOCK | FGP_ACCESSED | FGP_CREAT, GFP_NOFS);
> +		if (IS_ERR(folio)) {
> +			ret = PTR_ERR(folio);
>  			mlog_errno(ret);
>  			break;
>  		}
> @@ -2945,9 +2946,9 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  		 * page, so write it back.
>  		 */
>  		if (PAGE_SIZE <= OCFS2_SB(sb)->s_clustersize) {
> -			if (PageDirty(page)) {
> -				unlock_page(page);
> -				put_page(page);
> +			if (folio_test_dirty(folio)) {
> +				folio_unlock(folio);
> +				folio_put(folio);
>  
>  				ret = filemap_write_and_wait_range(mapping,
>  						offset, map_end - 1);
> @@ -2955,9 +2956,7 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  			}
>  		}
>  
> -		if (!PageUptodate(page)) {
> -			struct folio *folio = page_folio(page);
> -
> +		if (!folio_test_uptodate(folio)) {
>  			ret = block_read_full_folio(folio, ocfs2_get_block);
>  			if (ret) {
>  				mlog_errno(ret);
> @@ -2966,8 +2965,8 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  			folio_lock(folio);
>  		}
>  
> -		if (page_has_buffers(page)) {
> -			ret = walk_page_buffers(handle, page_buffers(page),
> +		if (folio_buffers(folio)) {
> +			ret = walk_page_buffers(handle, folio_buffers(folio),
>  						from, to, &partial,
>  						ocfs2_clear_cow_buffer);
>  			if (ret) {
> @@ -2978,12 +2977,11 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
>  
>  		ocfs2_map_and_dirty_page(inode,
>  					 handle, from, to,
> -					 page, 0, &new_block);
> -		mark_page_accessed(page);
> +					 &folio->page, 0, &new_block);
> +		folio_mark_accessed(folio);
>  unlock:
> -		unlock_page(page);
> -		put_page(page);
> -		page = NULL;
> +		folio_unlock(folio);
> +		folio_put(folio);
>  		offset = map_end;
>  		if (ret)
>  			break;