svn commit: r226963 - stable/9/sys/fs/nullfs

[Peter Holm]

Author: pho
Date: Mon Oct 31 09:18:01 2011
New Revision: 226963
URL: http://svn.freebsd.org/changeset/base/226963

Log:
  MFC r226681:
  Only unlock if the lock is exclusive.
  
  Approved by:	re (kib)
  PR:		kern/161956

Modified:
  stable/9/sys/fs/nullfs/null_vfsops.c
Directory Properties:
  stable/9/sys/   (props changed)
  stable/9/sys/amd64/include/xen/   (props changed)
  stable/9/sys/boot/   (props changed)
  stable/9/sys/boot/i386/efi/   (props changed)
  stable/9/sys/boot/ia64/efi/   (props changed)
  stable/9/sys/boot/ia64/ski/   (props changed)
  stable/9/sys/boot/powerpc/boot1.chrp/   (props changed)
  stable/9/sys/boot/powerpc/ofw/   (props changed)
  stable/9/sys/cddl/contrib/opensolaris/   (props changed)
  stable/9/sys/conf/   (props changed)
  stable/9/sys/contrib/dev/acpica/   (props changed)
  stable/9/sys/contrib/octeon-sdk/   (props changed)
  stable/9/sys/contrib/pf/   (props changed)
  stable/9/sys/contrib/x86emu/   (props changed)

Modified: stable/9/sys/fs/nullfs/null_vfsops.c
==============================================================================
--- stable/9/sys/fs/nullfs/null_vfsops.c	Mon Oct 31 09:06:33 2011	(r226962)
+++ stable/9/sys/fs/nullfs/null_vfsops.c	Mon Oct 31 09:18:01 2011	(r226963)
@@ -104,11 +104,10 @@ nullfs_mount(struct mount *mp)
 		return (EINVAL);
 
 	/*
-	 * Unlock lower node to avoid deadlock.
-	 * (XXX) VOP_ISLOCKED is needed?
+	 * Unlock lower node to avoid possible deadlock.
 	 */
 	if ((mp->mnt_vnodecovered->v_op == &null_vnodeops) &&
-		VOP_ISLOCKED(mp->mnt_vnodecovered)) {
+	    VOP_ISLOCKED(mp->mnt_vnodecovered) == LK_EXCLUSIVE) {
 		VOP_UNLOCK(mp->mnt_vnodecovered, 0);
 		isvnunlocked = 1;
 	}