linux-kernel - Re: [PATCH 1/2] f2fs: introduce {page,io}_is

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Message-ID: <20190823145738.GA35310@jaegeuk-macbookpro.roam.corp.google.com>
Date:   Fri, 23 Aug 2019 07:57:38 -0700
From:   Jaegeuk Kim <jaegeuk@...nel.org>
To:     Chao Yu <yuchao0@...wei.com>
Cc:     linux-f2fs-devel@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org, chao@...nel.org
Subject: Re: [PATCH 1/2] f2fs: introduce {page,io}_is_mergeable() for
 readability

On 08/23, Chao Yu wrote:
> 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@...wei.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.

Fixed, thanks,

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