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Date: Fri, 18 Apr 1997 23:04:20 -0700 (PDT)
From: KATO Takenori <kato>
Message-Id: <199704190604.XAA28022@freefall.freebsd.org>
To: CVS-committers, cvs-all, cvs-sys
Subject: cvs commit:  src/sys/miscfs/union union_vfsops.c src/sys/miscfs/nullfs null_vfsops.c
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kato        97/04/18 23:04:17

  Modified:    sys/miscfs/nullfs  null_vfsops.c
               sys/miscfs/union  union_vfsops.c
  Log:
  Avoid `lock against myself' panic by following operation:
  
  	# mount -t union (or null) dir1 dir2
  	# mount -t union (or null) dir2 dir1
  
  The function namei in union_mount calls union_root.  The upper vnode
  has been already locked and vn_lock in union_root causes above panic.
  
  Add printf's included in `#ifdef DIAGNOSTIC' for EDEADLK cases.
  
  Revision  Changes    Path
  1.17      +17 -4     src/sys/miscfs/nullfs/null_vfsops.c
  1.16      +16 -2     src/sys/miscfs/union/union_vfsops.c