From a4fc4a0c45f2617c3aa8b693739de264e0c09909 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 7 Nov 2023 21:26:40 +0000 Subject: mm: add folio_zero_tail() and use it in ext4 Patch series "Add folio_zero_tail() and folio_fill_tail()". I'm trying to make it easier for filesystems with tailpacking / stuffing / inline data to use folios. The primary function here is folio_fill_tail(). You give it a pointer to memory where the data currently is, and it takes care of copying it into the folio at that offset. That works for gfs2 & iomap. Then There's Ext4. Rather than gin up some kind of specialist "Here's a two pointers to two blocks of memory" routine, just let it do its current thing, and let it call folio_zero_tail(), which is also called by folio_fill_tail(). Other filesystems can be converted later; these ones seemed like good examples as they're already partly or completely converted to folios. This patch (of 3): Instead of unmapping the folio after copying the data to it, then mapping it again to zero the tail, provide folio_zero_tail() to zero the tail of an already-mapped folio. [akpm@linux-foundation.org: fix kerneldoc argument ordering] Link: https://lkml.kernel.org/r/20231107212643.3490372-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231107212643.3490372-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Andreas Gruenbacher Cc: Darrick J. Wong Cc: Theodore Ts'o Signed-off-by: Andrew Morton --- fs/ext4/inline.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs/ext4/inline.c') diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index 9a84a5f9fef4..d5bd1e3a5d36 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -502,9 +502,8 @@ static int ext4_read_inline_folio(struct inode *inode, struct folio *folio) BUG_ON(len > PAGE_SIZE); kaddr = kmap_local_folio(folio, 0); ret = ext4_read_inline_data(inode, kaddr, len, &iloc); - flush_dcache_folio(folio); + kaddr = folio_zero_tail(folio, len, kaddr + len); kunmap_local(kaddr); - folio_zero_segment(folio, len, folio_size(folio)); folio_mark_uptodate(folio); brelse(iloc.bh); -- cgit