Re: kern/48135: Bad locking for umount

["J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>]

The following reply was made to PR kern/48135; it has been noted by GNATS.

From: "J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/48135: Bad locking for umount
Date: Wed, 21 Aug 2013 11:13:54 +0200

 This fix looks wrong.
 
 If it is possible for the (last) reference to go away while vfs_busy() is
 running it is also unsafe to increment the reference counter here as it
 could be zero and be freed from vfs_destroy().
 
 Do you have stack traces from the threads running vfs_busy()
 and vfs_destroy()?
 
 --
 J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig 
(Germany)