From owner-freebsd-bugs@freebsd.org Thu Dec 3 02:11:33 2015 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DF059A3F9DE for ; Thu, 3 Dec 2015 02:11:33 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C0A07123A for ; Thu, 3 Dec 2015 02:11:33 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id tB32BXWk026451 for ; Thu, 3 Dec 2015 02:11:33 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 204949] panic: mtx_lock of spin mutex @ /usr/src/head/sys/kern/vfs_subr.c:512 Date: Thu, 03 Dec 2015 02:11:34 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: mckusick@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Dec 2015 02:11:34 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=204949 --- Comment #12 from Kirk McKusick --- The proposed fix by Mateusz Guzik is correct. Prior to my changes to vfs_subr.c the v_mountedhere union element was always zero'ed. Following my changes it was not. In the lookup function, it checks to see if v_mountedhere != NULL, and if it is not NULL assumes that it points to a struct mount and passes it to vfs_busy. If it contains a pointer to some other structure from a previous use of the vnode, the call to vfs_busy chokes when it attempts to dereference a mount mutex. I have committed the fix as noted in the above comment. -- You are receiving this mail because: You are the assignee for the bug.