Re: [PATCH 2/7] ext4: fold ext4_generic_write_end() into ext4_write_end()

["Lukáš Czerner" <lczerner@redhat.com>]

On Sun, 24 Mar 2013, Theodore Ts'o wrote:

> Date: Sun, 24 Mar 2013 20:06:49 -0400
> From: Theodore Ts'o <tytso@mit.edu>
> To: Ext4 Developers List <linux-ext4@vger.kernel.org>
> Cc: Zheng Liu <wenqing.lz@taobao.com>, Theodore Ts'o <tytso@mit.edu>
> Subject: [PATCH 2/7] ext4: fold ext4_generic_write_end() into ext4_write_end()
> 
> From: Zheng Liu <wenqing.lz@taobao.com>
> 
> After collpasing the handling of data ordered and data writeback
> codepath, ext4_generic_write_end() has only one caller,
> ext4_write_end().  So we fold it into ext4_write_end().

Looks good.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>

Thanks!
-Lukas

> 
> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
> ---
>  fs/ext4/inode.c | 67 +++++++++++++++++++++++----------------------------------
>  1 file changed, 27 insertions(+), 40 deletions(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 4ee6927..a4ffb47 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1087,14 +1087,32 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh)
>  	return ext4_handle_dirty_metadata(handle, NULL, bh);
>  }
>  
> -static int ext4_generic_write_end(struct file *file,
> -				  struct address_space *mapping,
> -				  loff_t pos, unsigned len, unsigned copied,
> -				  struct page *page, void *fsdata)
> +/*
> + * We need to pick up the new inode size which generic_commit_write gave us
> + * `file' can be NULL - eg, when called from page_symlink().
> + *
> + * ext4 never places buffers on inode->i_mapping->private_list.  metadata
> + * buffers are managed internally.
> + */
> +static int ext4_write_end(struct file *file,
> +			  struct address_space *mapping,
> +			  loff_t pos, unsigned len, unsigned copied,
> +			  struct page *page, void *fsdata)
>  {
> -	int i_size_changed = 0;
> -	struct inode *inode = mapping->host;
>  	handle_t *handle = ext4_journal_current_handle();
> +	struct inode *inode = mapping->host;
> +	int ret = 0, ret2;
> +	int i_size_changed = 0;
> +
> +	trace_ext4_write_end(inode, pos, len, copied);
> +	if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
> +		ret = ext4_jbd2_file_inode(handle, inode);
> +		if (ret) {
> +			unlock_page(page);
> +			page_cache_release(page);
> +			goto errout;
> +		}
> +	}
>  
>  	if (ext4_has_inline_data(inode))
>  		copied = ext4_write_inline_data_end(inode, pos, len,
> @@ -1105,7 +1123,7 @@ static int ext4_generic_write_end(struct file *file,
>  
>  	/*
>  	 * No need to use i_size_read() here, the i_size
> -	 * cannot change under us because we hold i_mutex.
> +	 * cannot change under us because we hole i_mutex.
>  	 *
>  	 * But it's important to update i_size while still holding page lock:
>  	 * page writeout could otherwise come in and zero beyond i_size.
> @@ -1115,10 +1133,10 @@ static int ext4_generic_write_end(struct file *file,
>  		i_size_changed = 1;
>  	}
>  
> -	if (pos + copied >  EXT4_I(inode)->i_disksize) {
> +	if (pos + copied > EXT4_I(inode)->i_disksize) {
>  		/* We need to mark inode dirty even if
>  		 * new_i_size is less that inode->i_size
> -		 * bu greater than i_disksize.(hint delalloc)
> +		 * but greater than i_disksize. (hint delalloc)
>  		 */
>  		ext4_update_i_disksize(inode, (pos + copied));
>  		i_size_changed = 1;
> @@ -1135,37 +1153,6 @@ static int ext4_generic_write_end(struct file *file,
>  	if (i_size_changed)
>  		ext4_mark_inode_dirty(handle, inode);
>  
> -	return copied;
> -}
> -
> -/*
> - * We need to pick up the new inode size which generic_commit_write gave us
> - * `file' can be NULL - eg, when called from page_symlink().
> - *
> - * ext4 never places buffers on inode->i_mapping->private_list.  metadata
> - * buffers are managed internally.
> - */
> -static int ext4_write_end(struct file *file,
> -			  struct address_space *mapping,
> -			  loff_t pos, unsigned len, unsigned copied,
> -			  struct page *page, void *fsdata)
> -{
> -	handle_t *handle = ext4_journal_current_handle();
> -	struct inode *inode = mapping->host;
> -	int ret = 0, ret2;
> -
> -	trace_ext4_write_end(inode, pos, len, copied);
> -	if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
> -		ret = ext4_jbd2_file_inode(handle, inode);
> -		if (ret) {
> -			unlock_page(page);
> -			page_cache_release(page);
> -			goto errout;
> -		}
> -	}
> -
> -	copied = ext4_generic_write_end(file, mapping, pos, len, copied,
> -					page, fsdata);
>  	if (copied < 0)
>  		ret = copied;
>  	if (pos + len > inode->i_size && ext4_can_truncate(inode))
>