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Subject: Re: [PATCH 1/2] f2fs: introduce {page,io}_is_mergeable() for
 readability
To:     <jaegeuk@kernel.org>
CC:     <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>, <chao@kernel.org>
References: <20190712085542.4068-1-yuchao0@huawei.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <28424a84-67aa-c8e9-99c3-475be89206ac@huawei.com>
Date:   Fri, 23 Aug 2019 11:02:41 +0800
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On 2019/7/12 16:55, Chao Yu wrote:
> Wrap merge condition into function for readability, no logic change.
> 
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
> v2: remove bio validation check in page_is_mergeable().
>  fs/f2fs/data.c | 40 +++++++++++++++++++++++++++++++++-------
>  1 file changed, 33 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 6a8db4abdf5f..f1e401f9fc13 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -482,6 +482,33 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
>  	return 0;
>  }
>  
> +static bool page_is_mergeable(struct f2fs_sb_info *sbi, struct bio *bio,
> +				block_t last_blkaddr, block_t cur_blkaddr)
> +{
> +	if (last_blkaddr != cur_blkaddr)

if (last_blkaddr + 1 != cur_blkaddr)

Merge condition is wrong here.

> +		return false;
> +	return __same_bdev(sbi, cur_blkaddr, bio);
> +}
> +
> +static bool io_type_is_mergeable(struct f2fs_bio_info *io,
> +						struct f2fs_io_info *fio)
> +{
> +	if (io->fio.op != fio->op)
> +		return false;
> +	return io->fio.op_flags == fio->op_flags;
> +}
> +
> +static bool io_is_mergeable(struct f2fs_sb_info *sbi, struct bio *bio,
> +					struct f2fs_bio_info *io,
> +					struct f2fs_io_info *fio,
> +					block_t last_blkaddr,
> +					block_t cur_blkaddr)
> +{
> +	if (!page_is_mergeable(sbi, bio, last_blkaddr, cur_blkaddr))
> +		return false;
> +	return io_type_is_mergeable(io, fio);
> +}
> +
>  int f2fs_merge_page_bio(struct f2fs_io_info *fio)
>  {
>  	struct bio *bio = *fio->bio;
> @@ -495,8 +522,8 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
>  	trace_f2fs_submit_page_bio(page, fio);
>  	f2fs_trace_ios(fio, 0);
>  
> -	if (bio && (*fio->last_block + 1 != fio->new_blkaddr ||
> -			!__same_bdev(fio->sbi, fio->new_blkaddr, bio))) {
> +	if (bio && !page_is_mergeable(fio->sbi, bio, *fio->last_block,
> +						fio->new_blkaddr)) {
>  		__submit_bio(fio->sbi, bio, fio->type);
>  		bio = NULL;
>  	}
> @@ -569,9 +596,8 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
>  
>  	inc_page_count(sbi, WB_DATA_TYPE(bio_page));
>  
> -	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
> -	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
> -			!__same_bdev(sbi, fio->new_blkaddr, io->bio)))
> +	if (io->bio && !io_is_mergeable(sbi, io->bio, io, fio,
> +			io->last_block_in_bio, fio->new_blkaddr))
>  		__submit_merged_bio(io);
>  alloc_new:
>  	if (io->bio == NULL) {
> @@ -1643,8 +1669,8 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
>  	 * This page will go to BIO.  Do we need to send this
>  	 * BIO off first?
>  	 */
> -	if (bio && (*last_block_in_bio != block_nr - 1 ||
> -		!__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
> +	if (bio && !page_is_mergeable(F2FS_I_SB(inode), bio,
> +				*last_block_in_bio, block_nr - 1)) {

*last_block_in_bio, block_nr)

Sorry, anyway, let me send v2.

>  submit_and_realloc:
>  		__submit_bio(F2FS_I_SB(inode), bio, DATA);
>  		bio = NULL;
>