From 64dd161f4db6b6d303fb4da851ea5e1426a4aa1b Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 14 Dec 2021 09:22:12 +0000 Subject: [PATCH] afs: Fix mmap Fix afs_add_open_map() to check that the vnode isn't already on the list when it adds it. It's possible that afs_drop_open_mmap() decremented the cb_nr_mmap counter, but hadn't yet got into the locked section to remove it. Also vnode->cb_mmap_link should be initialised, so fix that too. Fixes: 5c5ec604ae2a ("afs: Fix mmap coherency vs 3rd-party changes") Reported-by: kafs-testing+fedora34_64checkkafs-build-300@auristor.com Suggested-by: Marc Dionne Signed-off-by: David Howells Tested-by: kafs-testing+fedora34_64checkkafs-build-300@auristor.com cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/686465.1639435380@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds --- fs/afs/file.c | 5 +++-- fs/afs/super.c | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/afs/file.c b/fs/afs/file.c index cb6ad61eec3bf..afe4b803f84b4 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -514,8 +514,9 @@ static void afs_add_open_mmap(struct afs_vnode *vnode) if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) { down_write(&vnode->volume->cell->fs_open_mmaps_lock); - list_add_tail(&vnode->cb_mmap_link, - &vnode->volume->cell->fs_open_mmaps); + if (list_empty(&vnode->cb_mmap_link)) + list_add_tail(&vnode->cb_mmap_link, + &vnode->volume->cell->fs_open_mmaps); up_write(&vnode->volume->cell->fs_open_mmaps_lock); } diff --git a/fs/afs/super.c b/fs/afs/super.c index d110def8aa8eb..34c68724c98be 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -667,6 +667,7 @@ static void afs_i_init_once(void *_vnode) INIT_LIST_HEAD(&vnode->pending_locks); INIT_LIST_HEAD(&vnode->granted_locks); INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work); + INIT_LIST_HEAD(&vnode->cb_mmap_link); seqlock_init(&vnode->cb_lock); } -- 2.39.5