On Fri, Aug 23, 2024 at 12:03 PM Josef Bacik <josef@xxxxxxxxxxxxxx> wrote:
>
> On Fri, Aug 23, 2024 at 09:27:27AM -0700, Joanne Koong wrote:
> > To pave the way for refactoring out the shared logic in
> > fuse_writepages_fill() and fuse_writepage_locked(), this change converts
> > the temporary page in fuse_writepages_fill() to use the folio API.
> >
> > This is similar to the change in e0887e095a80 ("fuse: Convert
> > fuse_writepage_locked to take a folio"), which converted the tmp page in
> > fuse_writepage_locked() to use the folio API.
> >
> > inc_node_page_state() is intentionally preserved here instead of
> > converting to node_stat_add_folio() since it is updating the stat of the
> > underlying page and to better maintain API symmetry with
> > dec_node_page_stat() in fuse_writepage_finish_stat().
> >
> > No functional changes added.
> >
> > Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
> > ---
> > fs/fuse/file.c | 14 +++++++-------
> > 1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> > index a51b0b085616..905b202a7acd 100644
> > --- a/fs/fuse/file.c
> > +++ b/fs/fuse/file.c
> > @@ -2260,7 +2260,7 @@ static int fuse_writepages_fill(struct folio *folio,
> > struct inode *inode = data->inode;
> > struct fuse_inode *fi = get_fuse_inode(inode);
> > struct fuse_conn *fc = get_fuse_conn(inode);
> > - struct page *tmp_page;
> > + struct folio *tmp_folio;
> > int err;
> >
> > if (wpa && fuse_writepage_need_send(fc, &folio->page, ap, data)) {
> > @@ -2269,8 +2269,8 @@ static int fuse_writepages_fill(struct folio *folio,
> > }
> >
> > err = -ENOMEM;
> > - tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
> > - if (!tmp_page)
> > + tmp_folio = folio_alloc(GFP_NOFS | __GFP_HIGHMEM, 0);
> > + if (!tmp_folio)
> > goto out_unlock;
> >
> > /*
> > @@ -2290,7 +2290,7 @@ static int fuse_writepages_fill(struct folio *folio,
> > err = -ENOMEM;
> > wpa = fuse_writepage_args_alloc();
> > if (!wpa) {
> > - __free_page(tmp_page);
> > + folio_put(tmp_folio);
> > goto out_unlock;
> > }
> > fuse_writepage_add_to_bucket(fc, wpa);
> > @@ -2308,14 +2308,14 @@ static int fuse_writepages_fill(struct folio *folio,
> > }
> > folio_start_writeback(folio);
> >
> > - copy_highpage(tmp_page, &folio->page);
> > - ap->pages[ap->num_pages] = tmp_page;
> > + folio_copy(tmp_folio, folio);
> > + ap->pages[ap->num_pages] = &tmp_folio->page;
> > ap->descs[ap->num_pages].offset = 0;
> > ap->descs[ap->num_pages].length = PAGE_SIZE;
> > data->orig_pages[ap->num_pages] = &folio->page;
> >
> > inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
> > - inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
> > + inc_node_page_state(&tmp_folio->page, NR_WRITEBACK_TEMP);
>
> I *think* you can use
>
> node_stat_add_folio(tmp_folio, NR_WRITEBACK_TEMP);
>
> here instead of inc_node_page_state(). Thanks,
I was thinking inc_node_page_state() here would be better for
preserving the API symmetry with the dec_node_page_state() function
that gets called when the writeback gets finished (in
fuse_writepage_finish_stat) - I don't think it's immediately obvious
that node_stat_add_folio() and dec_node_page_state() are inverses of
each other. I don't feel strongly about this though, so i'm happy to
change this to node_stat_add_folio as well.
Thanks,
Joanne
>
> Josef
