svn commit: r259522 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Tue Dec 17 17:31:16 2013
New Revision: 259522
URL: http://svnweb.freebsd.org/changeset/base/259522

Log:
  If vn_open_vnode() succeeded in opening the vnode, but subsequent
  advisory lock cannot be obtained, prevent double-close of the vnode in
  vn_close() called from the fdrop(), by resetting file' f_ops methods.
  
  Reported and tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/kern/vfs_vnops.c

Modified: head/sys/kern/vfs_vnops.c
==============================================================================
--- head/sys/kern/vfs_vnops.c	Tue Dec 17 17:28:02 2013	(r259521)
+++ head/sys/kern/vfs_vnops.c	Tue Dec 17 17:31:16 2013	(r259522)
@@ -313,6 +313,9 @@ vn_open_vnode(struct vnode *vp, int fmod
 			vn_lock(vp, lock_flags | LK_RETRY);
 			(void)VOP_CLOSE(vp, fmode, cred, td);
 			vn_finished_write(mp);
+			/* Prevent second close from fdrop()->vn_close(). */
+			if (fp != NULL)
+				fp->f_ops= &badfileops;
 			return (error);
 		}
 		fp->f_flag |= FHASLOCK;