From owner-freebsd-bugs@freebsd.org Thu Dec 28 13:09:05 2017 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 D3425E8EA42 for ; Thu, 28 Dec 2017 13:09:05 +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 C1F8A79CD6 for ; Thu, 28 Dec 2017 13:09:05 +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 vBSD94fn047845 for ; Thu, 28 Dec 2017 13:09:05 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 224479] kernel panic in reboot+swapoff sys call Date: Thu, 28 Dec 2017 13:09:05 +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: CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: avg@FreeBSD.org X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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: 2.1.25 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Dec 2017 13:09:05 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D224479 --- Comment #15 from Andriy Gapon --- (In reply to Konstantin Belousov from comment #14) On the other hand, if the kernel knows that a vnode is used for swap and the kernel knows that the force reclaim of that vnode will lead to a panic, then why should the kernel allow that? I see several possibilities, but not sure if any of them makes sense from t= he FreeBSD architecture and design point of view. 1. When vgone-ing the swap vnode somehow perform an equivalent of swap off = on it. 2. Do not allow even the force unmount of a filesystem if there is a vnode = used for swap. 3. "Orphan" the swap vnode such that it is removed from its mount list, the name cache, etc, but it is still alive and is owned by the swap pager. I fe= el that this is impossible to do, however. Also, I am not sure about any "race", but it seems that during a shutdown we should first turn off all the file-backed swap and only then start unmounti= ng filesystems. From comment #0 it seems that we do not follow this order. --=20 You are receiving this mail because: You are the assignee for the bug.=