svn commit: r256078 - stable/9/sys/kern

[Konstantin Belousov]

Author: kib
Date: Sun Oct  6 06:14:29 2013
New Revision: 256078
URL: http://svnweb.freebsd.org/changeset/base/256078

Log:
  MFC r255942:
  For vunref(), try to upgrade the vnode lock if the function was called
  with the vnode shared-locked.

Modified:
  stable/9/sys/kern/vfs_subr.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/kern/vfs_subr.c
==============================================================================
--- stable/9/sys/kern/vfs_subr.c	Sun Oct  6 06:09:43 2013	(r256077)
+++ stable/9/sys/kern/vfs_subr.c	Sun Oct  6 06:14:29 2013	(r256078)
@@ -2343,8 +2343,10 @@ vputx(struct vnode *vp, int func)
 		}
 		break;
 	case VPUTX_VUNREF:
-		if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
-			error = EBUSY;
+		if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
+			error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
+			VI_LOCK(vp);
+		}
 		break;
 	}
 	if (vp->v_usecount > 0)