Re: [PATCH v2 01/17] mm: drop "wait" parameter from write_one_page

From: Jan Kara <jack@suse.cz>
To: Jeff Layton <jlayton@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	akpm@linux-foundation.org, tytso@mit.edu, jack@suse.cz,
	willy@infradead.org, neilb@suse.com, viro@zeniv.linux.org.uk
Subject: Re: [PATCH v2 01/17] mm: drop "wait" parameter from write_one_page
Date: Wed, 12 Apr 2017 14:15:54 +0200	[thread overview]
Message-ID: <20170412121554.GA1289@quack2.suse.cz> (raw)
In-Reply-To: <20170412120614.6111-2-jlayton@redhat.com>

On Wed 12-04-17 08:05:58, Jeff Layton wrote:
> The callers all set it to 1. Also, make it clear that this function will
> not set any sort of AS_* error, and that the caller must do so if
> necessary. No existing caller uses this on normal files, so none of them
> need it.
> 
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/exofs/dir.c        |  2 +-
>  fs/ext2/dir.c         |  2 +-
>  fs/jfs/jfs_metapage.c |  4 ++--
>  fs/minix/dir.c        |  2 +-
>  fs/sysv/dir.c         |  2 +-
>  fs/ufs/dir.c          |  2 +-
>  include/linux/mm.h    |  2 +-
>  mm/page-writeback.c   | 14 +++++++-------
>  8 files changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/fs/exofs/dir.c b/fs/exofs/dir.c
> index 42f9a0a0c4ca..e163ed980c20 100644
> --- a/fs/exofs/dir.c
> +++ b/fs/exofs/dir.c
> @@ -72,7 +72,7 @@ static int exofs_commit_chunk(struct page *page, loff_t pos, unsigned len)
>  	set_page_dirty(page);
>  
>  	if (IS_DIRSYNC(dir))
> -		err = write_one_page(page, 1);
> +		err = write_one_page(page);
>  	else
>  		unlock_page(page);
>  
> diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
> index d9650c9508e4..e2709695b177 100644
> --- a/fs/ext2/dir.c
> +++ b/fs/ext2/dir.c
> @@ -100,7 +100,7 @@ static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
>  	}
>  
>  	if (IS_DIRSYNC(dir)) {
> -		err = write_one_page(page, 1);
> +		err = write_one_page(page);
>  		if (!err)
>  			err = sync_inode_metadata(dir, 1);
>  	} else {
> diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
> index 489aaa1403e5..744fa3c079e6 100644
> --- a/fs/jfs/jfs_metapage.c
> +++ b/fs/jfs/jfs_metapage.c
> @@ -711,7 +711,7 @@ void force_metapage(struct metapage *mp)
>  	get_page(page);
>  	lock_page(page);
>  	set_page_dirty(page);
> -	write_one_page(page, 1);
> +	write_one_page(page);
>  	clear_bit(META_forcewrite, &mp->flag);
>  	put_page(page);
>  }
> @@ -756,7 +756,7 @@ void release_metapage(struct metapage * mp)
>  		set_page_dirty(page);
>  		if (test_bit(META_sync, &mp->flag)) {
>  			clear_bit(META_sync, &mp->flag);
> -			write_one_page(page, 1);
> +			write_one_page(page);
>  			lock_page(page); /* write_one_page unlocks the page */
>  		}
>  	} else if (mp->lsn)	/* discard_metapage doesn't remove it */
> diff --git a/fs/minix/dir.c b/fs/minix/dir.c
> index 7edc9b395700..baa9721f1299 100644
> --- a/fs/minix/dir.c
> +++ b/fs/minix/dir.c
> @@ -57,7 +57,7 @@ static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
>  		mark_inode_dirty(dir);
>  	}
>  	if (IS_DIRSYNC(dir))
> -		err = write_one_page(page, 1);
> +		err = write_one_page(page);
>  	else
>  		unlock_page(page);
>  	return err;
> diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
> index 5bdae85ceef7..f5191cb2c947 100644
> --- a/fs/sysv/dir.c
> +++ b/fs/sysv/dir.c
> @@ -45,7 +45,7 @@ static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
>  		mark_inode_dirty(dir);
>  	}
>  	if (IS_DIRSYNC(dir))
> -		err = write_one_page(page, 1);
> +		err = write_one_page(page);
>  	else
>  		unlock_page(page);
>  	return err;
> diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
> index de01b8f2aa78..48609f1d9580 100644
> --- a/fs/ufs/dir.c
> +++ b/fs/ufs/dir.c
> @@ -53,7 +53,7 @@ static int ufs_commit_chunk(struct page *page, loff_t pos, unsigned len)
>  		mark_inode_dirty(dir);
>  	}
>  	if (IS_DIRSYNC(dir))
> -		err = write_one_page(page, 1);
> +		err = write_one_page(page);
>  	else
>  		unlock_page(page);
>  	return err;
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 00a8fa7e366a..f25b76486645 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2187,7 +2187,7 @@ extern void filemap_map_pages(struct vm_fault *vmf,
>  extern int filemap_page_mkwrite(struct vm_fault *vmf);
>  
>  /* mm/page-writeback.c */
> -int write_one_page(struct page *page, int wait);
> +int write_one_page(struct page *page);
>  void task_dirty_inc(struct task_struct *tsk);
>  
>  /* readahead.c */
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index d8ac2a7fb9e7..de0dbf12e2c1 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -2361,15 +2361,16 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
>  }
>  
>  /**
> - * write_one_page - write out a single page and optionally wait on I/O
> + * write_one_page - write out a single page and wait on I/O
>   * @page: the page to write
> - * @wait: if true, wait on writeout
>   *
>   * The page must be locked by the caller and will be unlocked upon return.
>   *
> - * write_one_page() returns a negative error code if I/O failed.
> + * write_one_page() returns a negative error code if I/O failed. Note that
> + * the address_space is not marked for error. The caller must do this if
> + * needed.
>   */
> -int write_one_page(struct page *page, int wait)
> +int write_one_page(struct page *page)
>  {
>  	struct address_space *mapping = page->mapping;
>  	int ret = 0;
> @@ -2380,13 +2381,12 @@ int write_one_page(struct page *page, int wait)
>  
>  	BUG_ON(!PageLocked(page));
>  
> -	if (wait)
> -		wait_on_page_writeback(page);
> +	wait_on_page_writeback(page);
>  
>  	if (clear_page_dirty_for_io(page)) {
>  		get_page(page);
>  		ret = mapping->a_ops->writepage(page, &wbc);
> -		if (ret == 0 && wait) {
> +		if (ret == 0) {
>  			wait_on_page_writeback(page);
>  			if (PageError(page))
>  				ret = -EIO;
> -- 
> 2.9.3
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR