Re: [PATCH] exfat: remove 'rwoffset' in exfat_inode_info

[Tetsuhiro Kohada]

On 2020/09/12 14:01, Sungjong Seo wrote:
> > Remove 'rwoffset' in exfat_inode_info and replace it with the
> > parameter(cpos) of exfat_readdir.
> > Since rwoffset of  is referenced only by exfat_readdir, it is not
> > necessary a exfat_inode_info's member.
> >
> > Signed-off-by: Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>
> > ---
> >   fs/exfat/dir.c      | 16 ++++++----------
> >   fs/exfat/exfat_fs.h |  2 --
> >   fs/exfat/file.c     |  2 --
> >   fs/exfat/inode.c    |  3 ---
> >   fs/exfat/super.c    |  1 -
> >   5 files changed, 6 insertions(+), 18 deletions(-)
> >
> > diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> > a9b13ae3f325..fa5bb72aa295 100644
> > --- a/fs/exfat/dir.c
> > +++ b/fs/exfat/dir.c
> [snip]
> > sector @@ -262,13 +260,11 @@ static int exfat_iterate(struct file *filp,
> > struct dir_context *ctx)
> >   		goto end_of_dir;
> >   	}
> >
> > -	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
> > -
> >   	if (!nb->lfn[0])
> >   		goto end_of_dir;
> >
> >   	i_pos = ((loff_t)ei->start_clu << 32) |
> > -		((ei->rwoffset - 1) & 0xffffffff);
> > +		(EXFAT_B_TO_DEN(cpos-1) & 0xffffffff);
>
> Need to fix the above line to be:
> (EXFAT_B_TO_DEN(cpos)-1)) & 0xffffffff);


Here, we simply converted so that the calculation results would be the same.
But after reading it carefully again, I noticed.
 - Why use the previous entry?
 - Why does cpos point to stream dir-entry in entry-set?

For the former, there is no need to "++dentry" in exfat_readdir().
For the latter, I think cpos should point to the next to current entry-set.

I'll make V2 considering these.
How do you think?

BR
---
Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>