[Ocfs2-devel] [PATCH 3/3] mm, jfs: move write_one_page/folio_write_one to jfs

[Dave Kleikamp]

On 3/7/23 8:31AM, Christoph Hellwig wrote:
> The last remaining user of folio_write_one through the write_one_page
> wrapper is jfs, so move the functionality there and hard code the
> call to metapage_writepage.
> 
> Note that the use of the pagecache by the JFS 'metapage' buffer cache
> is a bit odd, and we could probably do without VM-level dirty tracking
> at all, but that's a change for another time.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Acked-by: Dave Kleikamp <dave.kleikamp at oracle.com>

Was about to ack this and noticed I must have done it earlier. For the 
record, it looks good to me.

Shaggy

> ---
>   fs/jfs/jfs_metapage.c   | 39 ++++++++++++++++++++++++++++++++++-----
>   include/linux/pagemap.h |  6 ------
>   mm/page-writeback.c     | 40 ----------------------------------------
>   3 files changed, 34 insertions(+), 51 deletions(-)
> 
> diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
> index 2e8461ce74de69..961569c1115901 100644
> --- a/fs/jfs/jfs_metapage.c
> +++ b/fs/jfs/jfs_metapage.c
> @@ -691,6 +691,35 @@ void grab_metapage(struct metapage * mp)
>   	unlock_page(mp->page);
>   }
>   
> +static int metapage_write_one(struct page *page)
> +{
> +	struct folio *folio = page_folio(page);
> +	struct address_space *mapping = folio->mapping;
> +	struct writeback_control wbc = {
> +		.sync_mode = WB_SYNC_ALL,
> +		.nr_to_write = folio_nr_pages(folio),
> +	};
> +	int ret = 0;
> +
> +	BUG_ON(!folio_test_locked(folio));
> +
> +	folio_wait_writeback(folio);
> +
> +	if (folio_clear_dirty_for_io(folio)) {
> +		folio_get(folio);
> +		ret = metapage_writepage(page, &wbc);
> +		if (ret == 0)
> +			folio_wait_writeback(folio);
> +		folio_put(folio);
> +	} else {
> +		folio_unlock(folio);
> +	}
> +
> +	if (!ret)
> +		ret = filemap_check_errors(mapping);
> +	return ret;
> +}
> +
>   void force_metapage(struct metapage *mp)
>   {
>   	struct page *page = mp->page;
> @@ -700,8 +729,8 @@ void force_metapage(struct metapage *mp)
>   	get_page(page);
>   	lock_page(page);
>   	set_page_dirty(page);
> -	if (write_one_page(page))
> -		jfs_error(mp->sb, "write_one_page() failed\n");
> +	if (metapage_write_one(page))
> +		jfs_error(mp->sb, "metapage_write_one() failed\n");
>   	clear_bit(META_forcewrite, &mp->flag);
>   	put_page(page);
>   }
> @@ -746,9 +775,9 @@ void release_metapage(struct metapage * mp)
>   		set_page_dirty(page);
>   		if (test_bit(META_sync, &mp->flag)) {
>   			clear_bit(META_sync, &mp->flag);
> -			if (write_one_page(page))
> -				jfs_error(mp->sb, "write_one_page() failed\n");
> -			lock_page(page); /* write_one_page unlocks the page */
> +			if (metapage_write_one(page))
> +				jfs_error(mp->sb, "metapage_write_one() failed\n");
> +			lock_page(page);
>   		}
>   	} else if (mp->lsn)	/* discard_metapage doesn't remove it */
>   		remove_from_logsync(mp);
> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
> index 0acb8e1fb7afdc..853184a46411f4 100644
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@ -1066,12 +1066,6 @@ static inline void folio_cancel_dirty(struct folio *folio)
>   bool folio_clear_dirty_for_io(struct folio *folio);
>   bool clear_page_dirty_for_io(struct page *page);
>   void folio_invalidate(struct folio *folio, size_t offset, size_t length);
> -int __must_check folio_write_one(struct folio *folio);
> -static inline int __must_check write_one_page(struct page *page)
> -{
> -	return folio_write_one(page_folio(page));
> -}
> -
>   int __set_page_dirty_nobuffers(struct page *page);
>   bool noop_dirty_folio(struct address_space *mapping, struct folio *folio);
>   
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 516b1aa247e83f..db794399900734 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -2583,46 +2583,6 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
>   	return ret;
>   }
>   
> -/**
> - * folio_write_one - write out a single folio and wait on I/O.
> - * @folio: The folio to write.
> - *
> - * The folio must be locked by the caller and will be unlocked upon return.
> - *
> - * Note that the mapping's AS_EIO/AS_ENOSPC flags will be cleared when this
> - * function returns.
> - *
> - * Return: %0 on success, negative error code otherwise
> - */
> -int folio_write_one(struct folio *folio)
> -{
> -	struct address_space *mapping = folio->mapping;
> -	int ret = 0;
> -	struct writeback_control wbc = {
> -		.sync_mode = WB_SYNC_ALL,
> -		.nr_to_write = folio_nr_pages(folio),
> -	};
> -
> -	BUG_ON(!folio_test_locked(folio));
> -
> -	folio_wait_writeback(folio);
> -
> -	if (folio_clear_dirty_for_io(folio)) {
> -		folio_get(folio);
> -		ret = mapping->a_ops->writepage(&folio->page, &wbc);
> -		if (ret == 0)
> -			folio_wait_writeback(folio);
> -		folio_put(folio);
> -	} else {
> -		folio_unlock(folio);
> -	}
> -
> -	if (!ret)
> -		ret = filemap_check_errors(mapping);
> -	return ret;
> -}
> -EXPORT_SYMBOL(folio_write_one);
> -
>   /*
>    * For address_spaces which do not use buffers nor write back.
>    */