diff options
| author | anton <anton@cvs.openbsd.org> | 2020-03-27 07:58:18 +0000 |
|---|---|---|
| committer | anton <anton@cvs.openbsd.org> | 2020-03-27 07:58:18 +0000 |
| commit | cea14634fd45b0fdfd49a60f8f65e1246c5c8612 (patch) | |
| tree | fe08b3b573168697a3b297b5b847db6fd594d2aa /sys/kern/vfs_subr.c | |
| parent | cd33168edafa403b5f33ed895072b8ded3c2b520 (diff) | |
Relax the lockcount assertion in vputonfreelist(). Back when I fixed
several problems with the vnode exclusive lock implementation, I
overlooked the fact that a vnode can be in a state where the usecount is
zero while the holdcount still being positive. There could still be
threads waiting on the vnode lock in uvn_io() as long as the holdcount
is positive.
"go ahead" mpi@
Reported-by: syzbot+767d6deb1a647850a0ca@syzkaller.appspotmail.com
Diffstat (limited to 'sys/kern/vfs_subr.c')
| -rw-r--r-- | sys/kern/vfs_subr.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index e6cb86795a1..8c015e44e40 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -1,4 +1,4 @@ -/* $OpenBSD: vfs_subr.c,v 1.300 2020/02/13 08:47:10 claudio Exp $ */ +/* $OpenBSD: vfs_subr.c,v 1.301 2020/03/27 07:58:17 anton Exp $ */ /* $NetBSD: vfs_subr.c,v 1.53 1996/04/22 01:39:13 christos Exp $ */ /* @@ -704,7 +704,11 @@ vputonfreelist(struct vnode *vp) if (vp->v_usecount != 0) panic("Use count is not zero!"); - if (vp->v_lockcount != 0) + /* + * If the hold count is still positive, one or many threads could still + * be waiting on the vnode lock inside uvn_io(). + */ + if (vp->v_holdcnt == 0 && vp->v_lockcount != 0) panic("%s: lock count is not zero", __func__); if (vp->v_bioflag & VBIOONFREELIST) { |