svn commit: r292961 - head/sys/fs/nullfs

[Konstantin Belousov]

Author: kib
Date: Wed Dec 30 19:49:22 2015
New Revision: 292961
URL: https://svnweb.freebsd.org/changeset/base/292961

Log:
  Force nullfs vnode reclaim after unlinking, to potentially unlink
  lower vnode.  Otherwise, reference to the lower vnode from the upper
  one prevents final unlink.
  
  PR:	178238
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/fs/nullfs/null_vnops.c

Modified: head/sys/fs/nullfs/null_vnops.c
==============================================================================
--- head/sys/fs/nullfs/null_vnops.c	Wed Dec 30 18:57:29 2015	(r292960)
+++ head/sys/fs/nullfs/null_vnops.c	Wed Dec 30 19:49:22 2015	(r292961)
@@ -568,14 +568,16 @@ static int
 null_remove(struct vop_remove_args *ap)
 {
 	int retval, vreleit;
-	struct vnode *lvp;
+	struct vnode *lvp, *vp;
 
-	if (vrefcnt(ap->a_vp) > 1) {
-		lvp = NULLVPTOLOWERVP(ap->a_vp);
+	vp = ap->a_vp;
+	if (vrefcnt(vp) > 1) {
+		lvp = NULLVPTOLOWERVP(vp);
 		VREF(lvp);
 		vreleit = 1;
 	} else
 		vreleit = 0;
+	VTONULL(vp)->null_flags |= NULLV_DROP;
 	retval = null_bypass(&ap->a_gen);
 	if (vreleit != 0)
 		vrele(lvp);