Commit a25def1f authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

iomap: Convert __iomap_zero_iter to use a folio 



The zero iterator can work in folio-sized chunks instead of page-sized
chunks.  This will save a lot of page cache lookups if the file is cached
in large folios.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent d454ab82

fs/iomap/buffered-io.c

+9 −5
Original line number Diff line number Diff line
@@ -893,19 +893,23 @@ EXPORT_SYMBOL_GPL(iomap_file_unshare); 


static s64 __iomap_zero_iter(struct iomap_iter *iter, loff_t pos, u64 length)

{

	struct folio *folio;

	struct page *page;

	int status;

	unsigned offset = offset_in_page(pos);

	size_t offset;

	unsigned bytes = min_t(u64, UINT_MAX, length);



	status = iomap_write_begin(iter, pos, bytes, &page);

	if (status)

		return status;

	if (bytes > PAGE_SIZE - offset)

		bytes = PAGE_SIZE - offset;

	folio = page_folio(page);



	offset = offset_in_folio(folio, pos);

	if (bytes > folio_size(folio) - offset)

		bytes = folio_size(folio) - offset;



	zero_user(page, offset, bytes);

	mark_page_accessed(page);

	folio_zero_range(folio, offset, bytes);

	folio_mark_accessed(folio);



	return iomap_write_end(iter, pos, bytes, bytes, page);

}