[Cluster-devel] [Ocfs2-devel] [PATCH 1/3] fs/buffer.c: add new api to allow eof writeback

[Joseph Qi]

On 4/27/21 6:05 AM, Junxiao Bi wrote:
> When doing truncate/fallocate for some filesytem like ocfs2, it
> will zero some pages that are out of inode size and then later
> update the inode size, so it needs this api to writeback eof
> pages.
> 
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Junxiao Bi <junxiao.bi at oracle.com>


Looks good.
Reviewed-by: Joseph Qi <joseph.qi at linux.alibaba.com>
> ---
>  fs/buffer.c                 | 14 +++++++++++---
>  include/linux/buffer_head.h |  3 +++
>  2 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 0cb7ffd4977c..802f0bacdbde 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -1709,9 +1709,9 @@ static struct buffer_head *create_page_buffers(struct page *page, struct inode *
>   * WB_SYNC_ALL, the writes are posted using REQ_SYNC; this
>   * causes the writes to be flagged as synchronous writes.
>   */
> -int __block_write_full_page(struct inode *inode, struct page *page,
> +int __block_write_full_page_eof(struct inode *inode, struct page *page,
>  			get_block_t *get_block, struct writeback_control *wbc,
> -			bh_end_io_t *handler)
> +			bh_end_io_t *handler, bool eof_write)
>  {
>  	int err;
>  	sector_t block;
> @@ -1746,7 +1746,7 @@ int __block_write_full_page(struct inode *inode, struct page *page,
>  	 * handle any aliases from the underlying blockdev's mapping.
>  	 */
>  	do {
> -		if (block > last_block) {
> +		if (block > last_block && !eof_write) {
>  			/*
>  			 * mapped buffers outside i_size will occur, because
>  			 * this page can be outside i_size when there is a
> @@ -1871,6 +1871,14 @@ int __block_write_full_page(struct inode *inode, struct page *page,
>  	unlock_page(page);
>  	goto done;
>  }
> +EXPORT_SYMBOL(__block_write_full_page_eof);
> +
> +int __block_write_full_page(struct inode *inode, struct page *page,
> +			get_block_t *get_block, struct writeback_control *wbc,
> +			bh_end_io_t *handler)
> +{
> +	return __block_write_full_page_eof(inode, page, get_block, wbc, handler, false);
> +}
>  EXPORT_SYMBOL(__block_write_full_page);
>  
>  /*
> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> index 6b47f94378c5..5da15a1ba15c 100644
> --- a/include/linux/buffer_head.h
> +++ b/include/linux/buffer_head.h
> @@ -221,6 +221,9 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
>  int __block_write_full_page(struct inode *inode, struct page *page,
>  			get_block_t *get_block, struct writeback_control *wbc,
>  			bh_end_io_t *handler);
> +int __block_write_full_page_eof(struct inode *inode, struct page *page,
> +			get_block_t *get_block, struct writeback_control *wbc,
> +			bh_end_io_t *handler, bool eof_write);
>  int block_read_full_page(struct page*, get_block_t*);
>  int block_is_partially_uptodate(struct page *page, unsigned long from,
>  				unsigned long count);
>