svn commit: r268609 - head/sys/fs/tmpfs

[Konstantin Belousov]

Author: kib
Date: Mon Jul 14 08:55:02 2014
New Revision: 268609
URL: http://svnweb.freebsd.org/changeset/base/268609

Log:
  Add some assertions for the code handling vm_object for tmpfs vnode.
  In particular, vnode must be exclusively locked when the tmpfs vnode
  and object are divorced.  When the vnode is opened, the object must be
  still alive, since only live vnode can be opened, and the tmpfs node
  owns a reference on the object.
  
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks

Modified:
  head/sys/fs/tmpfs/tmpfs_subr.c
  head/sys/fs/tmpfs/tmpfs_vnops.c

Modified: head/sys/fs/tmpfs/tmpfs_subr.c
==============================================================================
--- head/sys/fs/tmpfs/tmpfs_subr.c	Mon Jul 14 08:45:29 2014	(r268608)
+++ head/sys/fs/tmpfs/tmpfs_subr.c	Mon Jul 14 08:55:02 2014	(r268609)
@@ -428,6 +428,7 @@ void
 tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj)
 {
 
+	ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject");
 	if (vp->v_type != VREG || obj == NULL)
 		return;
 

Modified: head/sys/fs/tmpfs/tmpfs_vnops.c
==============================================================================
--- head/sys/fs/tmpfs/tmpfs_vnops.c	Mon Jul 14 08:45:29 2014	(r268608)
+++ head/sys/fs/tmpfs/tmpfs_vnops.c	Mon Jul 14 08:55:02 2014	(r268609)
@@ -258,6 +258,8 @@ tmpfs_open(struct vop_open_args *v)
 	else {
 		error = 0;
 		/* For regular files, the call below is nop. */
+		KASSERT(vp->v_type != VREG || (node->tn_reg.tn_aobj->flags &
+		    OBJ_DEAD) == 0, ("dead object"));
 		vnode_create_vobject(vp, node->tn_size, v->a_td);
 	}