Re: [PATCH v2 19/28] iomap: Convert __iomap_zero_iter to use a folio
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2021-11-17 02:24:26
Also in:
linux-fsdevel, linux-xfs, lkml
On Mon, Nov 08, 2021 at 04:05:42AM +0000, Matthew Wilcox (Oracle) wrote:
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 multi-page folios. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
hch's dax decoupling series notwithstanding, Though TBH I am kinda wondering how the two of you plan to resolve those kinds of differences -- I haven't looked at that series, though I think this one's been waiting in the wings for longer? Heck, I wonder how Matthew plans to merge all this given that it touches mm, fs, block, and iomap...? Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D
quoted hunk ↗ jump to hunk
--- fs/iomap/buffered-io.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 64e54981b651..9c61d12028ca 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c@@ -881,17 +881,20 @@ 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); - unsigned bytes = min_t(u64, PAGE_SIZE - offset, length); + size_t offset, bytes; - status = iomap_write_begin(iter, pos, bytes, &page); + status = iomap_write_begin(iter, pos, length, &page); if (status) return status; + folio = page_folio(page); - zero_user(page, offset, bytes); - mark_page_accessed(page); + offset = offset_in_folio(folio, pos); + bytes = min_t(u64, folio_size(folio) - offset, length); + folio_zero_range(folio, offset, bytes); + folio_mark_accessed(folio); return iomap_write_end(iter, pos, bytes, bytes, page); }-- 2.33.0