svn commit: r242617 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Mon Nov  5 16:40:42 2012
New Revision: 242617
URL: http://svnweb.freebsd.org/changeset/base/242617

Log:
  A clarification to the behaviour of the active vnode list management
  regarding the vnode page cleaning.
  
  In collaboration with:	pho
  MFC after:	1 week

Modified:
  head/sys/kern/vfs_subr.c

Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c	Mon Nov  5 15:23:54 2012	(r242616)
+++ head/sys/kern/vfs_subr.c	Mon Nov  5 16:40:42 2012	(r242617)
@@ -2507,6 +2507,9 @@ vinactive(struct vnode *vp, struct threa
 	 * Before moving off the active list, we must be sure that any
 	 * modified pages are on the vnode's dirty list since these will
 	 * no longer be checked once the vnode is on the inactive list.
+	 * Because the vnode vm object keeps a hold reference on the vnode
+	 * if there is at least one resident non-cached page, the vnode
+	 * cannot leave the active list without the page cleanup done.
 	 */
 	obj = vp->v_object;
 	if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {