Re: [PATCH 18/23] nilfs2: Convert nilfs_lookup_dirty_data_buffers() to use filemap_get_folios_tag()

Ryusuke Konishi
2022-09-03T17:38:45Z

On Fri, Sep 2, 2022 at 7:07 AM Vishal Moola (Oracle) wrote:
>
> Convert function to use folios throughout. This is in preparation for
> the removal of find_get_pages_range_tag().
>
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
> fs/nilfs2/segment.c | 29 ++++++++++++++++-------------
> 1 file changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
> index 0afe0832c754..e95c667bdc8f 100644
> --- a/fs/nilfs2/segment.c
> +++ b/fs/nilfs2/segment.c
> @@ -680,7 +680,7 @@ static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
> loff_t start, loff_t end)
> {
> struct address_space *mapping = inode->i_mapping;
> - struct pagevec pvec;
> + struct folio_batch fbatch;
> pgoff_t index = 0, last = ULONG_MAX;
> size_t ndirties = 0;
> int i;
> @@ -694,23 +694,26 @@ static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
> index = start >> PAGE_SHIFT;
> last = end >> PAGE_SHIFT;
> }
> - pagevec_init(&pvec);
> + folio_batch_init(&fbatch);
> repeat:
> if (unlikely(index > last) ||
> - !pagevec_lookup_range_tag(&pvec, mapping, &index, last,
> - PAGECACHE_TAG_DIRTY))
> + !filemap_get_folios_tag(mapping, &index, last,
> + PAGECACHE_TAG_DIRTY, &fbatch))
> return ndirties;
>
> - for (i = 0; i < pagevec_count(&pvec); i++) {
> + for (i = 0; i < folio_batch_count(&fbatch); i++) {
> struct buffer_head *bh, *head;
> - struct page *page = pvec.pages[i];
> + struct folio *folio = fbatch.folios[i];
>
> - lock_page(page);
> - if (!page_has_buffers(page))
> - create_empty_buffers(page, i_blocksize(inode), 0);
> - unlock_page(page);

> + head = folio_buffers(folio);
> + folio_lock(folio);

Could you please swap these two lines to keep the "head" check in the lock?

Thanks,
Ryusuke Konishi

> + if (!head) {
> + create_empty_buffers(&folio->page, i_blocksize(inode), 0);
> + head = folio_buffers(folio);
> + }
> + folio_unlock(folio);
>
> - bh = head = page_buffers(page);
> + bh = head;
> do {
> if (!buffer_dirty(bh) || buffer_async_write(bh))
> continue;
> @@ -718,13 +721,13 @@ static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
> list_add_tail(&bh->b_assoc_buffers, listp);
> ndirties++;
> if (unlikely(ndirties >= nlimit)) {
> - pagevec_release(&pvec);
> + folio_batch_release(&fbatch);
> cond_resched();
> return ndirties;
> }
> } while (bh = bh->b_this_page, bh != head);
> }
> - pagevec_release(&pvec);
> + folio_batch_release(&fbatch);
> cond_resched();
> goto repeat;
> }
> --
> 2.36.1
>