diff options
| author | kato <kato@FreeBSD.org> | 1997-04-26 04:09:40 +0000 |
|---|---|---|
| committer | kato <kato@FreeBSD.org> | 1997-04-26 04:09:40 +0000 |
| commit | f18676ff22d9297535b2acd920192c055db4ae2d (patch) | |
| tree | 086af2b8fcb3c6b10e0beb3795c05ec0f22ed28f /sys/miscfs | |
| parent | 80b96ecb2f86cc9a64bc39f7b7afb0f052645aef (diff) | |
| download | FreeBSD-src-f18676ff22d9297535b2acd920192c055db4ae2d.zip FreeBSD-src-f18676ff22d9297535b2acd920192c055db4ae2d.tar.gz | |
Do not clear UN_ULOCK in certain case.
Our vput calls vm_object_deallocate() --> vm_object_terminate(). The
vm_object_terminate() calls vn_lock(), since UN_LOCKED has been
already cleared in union_unlock(). Then, union_lock locks upper vnode
when UN_ULOCK is not set. The upper vnode is not unlocked when
UN_KLOCK is set in union_unlock(), thus, union_lock tries to lock
locked vnode and we get panic.
Diffstat (limited to 'sys/miscfs')
| -rw-r--r-- | sys/miscfs/union/union_vnops.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/sys/miscfs/union/union_vnops.c b/sys/miscfs/union/union_vnops.c index e90c5d49..cc632a2 100644 --- a/sys/miscfs/union/union_vnops.c +++ b/sys/miscfs/union/union_vnops.c @@ -35,7 +35,7 @@ * SUCH DAMAGE. * * @(#)union_vnops.c 8.32 (Berkeley) 6/23/95 - * $Id: union_vnops.c,v 1.26 1997/04/21 12:40:42 kato Exp $ + * $Id: union_vnops.c,v 1.27 1997/04/21 15:32:24 kato Exp $ */ #include <sys/param.h> @@ -1492,6 +1492,7 @@ start: panic("union_link: upper vnode is locked, " "but UN_UNLOCK is not set."); #endif + printf("union_lock: adjust un_flags\n"); un->un_flags |= UN_ULOCK; /* Adjust -- dirty */ } else { error = vn_lock(un->un_uppervp, flags, p); @@ -1565,7 +1566,16 @@ union_unlock(ap) if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK) VOP_UNLOCK(un->un_uppervp, 0, p); - un->un_flags &= ~(UN_ULOCK|UN_KLOCK); + if ((un->un_flags & UN_KLOCK) && (ap->a_vp->v_usecount == 1)) { + /* + * Do not clear UN_ULOCK here. Our vput will call + * VOP_LOCK for vm related reason. If we clear UN_ULOCK, + * VOP_LOCK will try to lock upper vnode, whic is not + * unlocked. + */ + un->un_flags &= ~UN_KLOCK; + } else + un->un_flags &= ~(UN_ULOCK|UN_KLOCK); if (un->un_flags & UN_WANT) { un->un_flags &= ~UN_WANT; |
