Re: [PATCH 1/2] f2fs: remove folio_detach_private() in .invalidate_folio and .release_folio

[Chao Yu]

On 2023/4/11 2:33, Jaegeuk Kim wrote:
> On 04/10, Chao Yu wrote:
> > We have maintain PagePrivate and page_private and page reference
> > w/ {set,clear}_page_private_*, it doesn't need to call
> > folio_detach_private() in the end of .invalidate_folio and
> > .release_folio, remove it and use f2fs_bug_on instead.
> >
> > Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
> > ---
> >   fs/f2fs/data.c | 7 +++++--
> >   1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 4946df6dd253..8b179b4bdc03 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -3737,7 +3737,8 @@ void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
> >   			inode->i_ino == F2FS_COMPRESS_INO(sbi))
> >   		clear_page_private_data(&folio->page);
> >   
> > -	folio_detach_private(folio);
> > +	f2fs_bug_on(sbi, PagePrivate(&folio->page));
> > +	f2fs_bug_on(sbi, page_private(&folio->page));
>
> I think we can just check page_private() only.

Why? how about the case PagePrivate was set, but page_private was't? It must
be a bug as well?

Thanks,

> >   }
> >   
> >   bool f2fs_release_folio(struct folio *folio, gfp_t wait)
> > @@ -3759,7 +3760,9 @@ bool f2fs_release_folio(struct folio *folio, gfp_t wait)
> >   	clear_page_private_reference(&folio->page);
> >   	clear_page_private_gcing(&folio->page);
> >   
> > -	folio_detach_private(folio);
> > +	f2fs_bug_on(sbi, PagePrivate(&folio->page));
> > +	f2fs_bug_on(sbi, page_private(&folio->page));
> > +
> >   	return true;
> >   }
> >   
> > --
> > 2.25.1