Re: kern/43439 (mount_null panic: lockdebug_wantlock: locking against myself)

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/43439; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: Antti Kantee <pooka%netbsd.org@localhost>
Subject: Re: kern/43439 (mount_null panic: lockdebug_wantlock: locking
        against myself)
Date: Thu, 10 Jun 2010 04:48:51 +0000

 On Wed, Jun 09, 2010 at 09:02:07AM +0000, hannken%NetBSD.org@localhost wrote:
  > Two possible solutions:
  > 1) Remove recursive vnode locks and move mount-on lookup into the
  > file systems
  > 2) Add a bypass function to layered file systems to pass vn_setrecurse down
 
 Also (3) rototill how mounting works so that you prepare the fs first
 and only then attach it to the namespace, which seems like the correct
 order of operations and would avoid this problem. I have no idea how
 hard this would be though.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost