Re: [PATCH 2/3] ntfs3: Use folios more in ntfs_compress_write()

[Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>]

On 5/14/25 19:06, Matthew Wilcox (Oracle) wrote:
> Remove the local 'page' variable and do everything in terms of folios.
> Removes the last user of copy_page_from_iter_atomic() and a hidden
> call to compound_head() in ClearPageDirty().
>
> Signed-off-by: Matthew Wilcox (Oracle)<willy@xxxxxxxxxxxxx>
> ---
>   fs/ntfs3/file.c | 31 +++++++++++++------------------
>   1 file changed, 13 insertions(+), 18 deletions(-)
>
> diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
> index 9b6a3f8d2e7c..bc6062e0668e 100644
> --- a/fs/ntfs3/file.c
> +++ b/fs/ntfs3/file.c
> @@ -998,7 +998,8 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   	struct ntfs_inode *ni = ntfs_i(inode);
>   	u64 valid = ni->i_valid;
>   	struct ntfs_sb_info *sbi = ni->mi.sbi;
> -	struct page *page, **pages = NULL;
> +	struct page **pages = NULL;
> +	struct folio *folio;
>   	size_t written = 0;
>   	u8 frame_bits = NTFS_LZNT_CUNIT + sbi->cluster_bits;
>   	u32 frame_size = 1u << frame_bits;
> @@ -1008,7 +1009,6 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   	u64 frame_vbo;
>   	pgoff_t index;
>   	bool frame_uptodate;
> -	struct folio *folio;
>   
>   	if (frame_size < PAGE_SIZE) {
>   		/*
> @@ -1062,8 +1062,7 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   					    pages_per_frame);
>   			if (err) {
>   				for (ip = 0; ip < pages_per_frame; ip++) {
> -					page = pages[ip];
> -					folio = page_folio(page);
> +					folio = page_folio(pages[ip]);
>   					folio_unlock(folio);
>   					folio_put(folio);
>   				}
> @@ -1074,10 +1073,9 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   		ip = off >> PAGE_SHIFT;
>   		off = offset_in_page(valid);
>   		for (; ip < pages_per_frame; ip++, off = 0) {
> -			page = pages[ip];
> -			folio = page_folio(page);
> -			zero_user_segment(page, off, PAGE_SIZE);
> -			flush_dcache_page(page);
> +			folio = page_folio(pages[ip]);
> +			folio_zero_segment(folio, off, PAGE_SIZE);
> +			flush_dcache_folio(folio);
>   			folio_mark_uptodate(folio);
>   		}
>   
> @@ -1086,8 +1084,7 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   		ni_unlock(ni);
>   
>   		for (ip = 0; ip < pages_per_frame; ip++) {
> -			page = pages[ip];
> -			folio = page_folio(page);
> +			folio = page_folio(pages[ip]);
>   			folio_mark_uptodate(folio);
>   			folio_unlock(folio);
>   			folio_put(folio);
> @@ -1131,8 +1128,7 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   				if (err) {
>   					for (ip = 0; ip < pages_per_frame;
>   					     ip++) {
> -						page = pages[ip];
> -						folio = page_folio(page);
> +						folio = page_folio(pages[ip]);
>   						folio_unlock(folio);
>   						folio_put(folio);
>   					}
> @@ -1150,10 +1146,10 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   		for (;;) {
>   			size_t cp, tail = PAGE_SIZE - off;
>   
> -			page = pages[ip];
> -			cp = copy_page_from_iter_atomic(page, off,
> +			folio = page_folio(pages[ip]);
> +			cp = copy_folio_from_iter_atomic(folio, off,
>   							min(tail, bytes), from);
> -			flush_dcache_page(page);
> +			flush_dcache_folio(folio);
>   
>   			copied += cp;
>   			bytes -= cp;
> @@ -1173,9 +1169,8 @@ static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
>   		ni_unlock(ni);
>   
>   		for (ip = 0; ip < pages_per_frame; ip++) {
> -			page = pages[ip];
> -			ClearPageDirty(page);
> -			folio = page_folio(page);
> +			folio = page_folio(pages[ip]);
> +			folio_clear_dirty(folio);
>   			folio_mark_uptodate(folio);
>   			folio_unlock(folio);
>   			folio_put(folio);

The changes look fine. Feel free to add them.