From d454ab82bc7f4aa7af9f539d5cf9a1e237cdcbc2 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 9 Dec 2021 15:47:44 -0500 Subject: [PATCH] iomap: Allow iomap_write_begin() to be called with the full length In the future, we want write_begin to know the entire length of the write so that it can choose to allocate large folios. Pass the full length in from __iomap_zero_iter() and limit it where necessary. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 8d7a67655b60..b1ded5204d1c 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -619,6 +619,9 @@ static int iomap_write_begin(const struct iomap_iter *iter, loff_t pos, if (fatal_signal_pending(current)) return -EINTR; + if (!mapping_large_folio_support(iter->inode->i_mapping)) + len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos)); + if (page_ops && page_ops->page_prepare) { status = page_ops->page_prepare(iter->inode, pos, len); if (status) @@ -632,6 +635,8 @@ static int iomap_write_begin(const struct iomap_iter *iter, loff_t pos, goto out_no_page; } folio = page_folio(page); + if (pos + len > folio_pos(folio) + folio_size(folio)) + len = folio_pos(folio) + folio_size(folio) - pos; if (srcmap->type == IOMAP_INLINE) status = iomap_write_begin_inline(iter, page); @@ -891,11 +896,13 @@ static s64 __iomap_zero_iter(struct iomap_iter *iter, loff_t pos, u64 length) struct page *page; int status; unsigned offset = offset_in_page(pos); - unsigned bytes = min_t(u64, PAGE_SIZE - offset, length); + 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; zero_user(page, offset, bytes); mark_page_accessed(page);