From f9a49aa302a05e91ca01f69031cb79a0ea33031f Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Mon, 5 Jan 2026 13:17:27 -0800 Subject: fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Above the while() loop in wait_sb_inodes(), we document that we must wait for all pages under writeback for data integrity. Consequently, if a mapping, like fuse, traditionally does not have data integrity semantics, there is no need to wait at all; we can simply skip these inodes. This restores fuse back to prior behavior where syncs are no-ops. This fixes a user regression where if a system is running a faulty fuse server that does not reply to issued write requests, this causes wait_sb_inodes() to wait forever. Link: https://lkml.kernel.org/r/20260105211737.4105620-2-joannelkoong@gmail.com Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") Signed-off-by: Joanne Koong Reported-by: Athul Krishna Reported-by: J. Neuschäfer Reviewed-by: Bernd Schubert Tested-by: J. Neuschäfer Cc: Alexander Viro Cc: Bernd Schubert Cc: Bonaccorso Salvatore Cc: Christian Brauner Cc: David Hildenbrand Cc: Jan Kara Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: "Matthew Wilcox (Oracle)" Cc: Michal Hocko Cc: Mike Rapoport Cc: Miklos Szeredi Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton --- fs/fs-writeback.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 6800886c4d10..baa2f2141146 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -2750,8 +2750,13 @@ static void wait_sb_inodes(struct super_block *sb) * The mapping can appear untagged while still on-list since we * do not have the mapping lock. Skip it here, wb completion * will remove it. + * + * If the mapping does not have data integrity semantics, + * there's no need to wait for the writeout to complete, as the + * mapping cannot guarantee that data is persistently stored. */ - if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) + if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK) || + mapping_no_data_integrity(mapping)) continue; spin_unlock_irq(&sb->s_inode_wblist_lock); -- cgit v1.2.3