From: David Howells dhowells@redhat.com
[ Upstream commit 1744a22ae948799da7927b53ec97ccc877ff9d61 ]
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: 6e0e99d58a65 ("afs: Fix mmap coherency vs 3rd-party changes") Reported-by: kafs-testing+fedora34_64checkkafs-build-300@auristor.com Suggested-by: Marc Dionne marc.dionne@auristor.com Signed-off-by: David Howells dhowells@redhat.com 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 torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 e6c447ae91f38..b165377179c3c 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -502,8 +502,9 @@ 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); }