From owner-freebsd-bugs@FreeBSD.ORG Tue Mar 3 17:17:54 2015 Return-Path: Delivered-To: freebsd-bugs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1792EDEA for ; Tue, 3 Mar 2015 17:17:54 +0000 (UTC) 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 D8DB3A68 for ; Tue, 3 Mar 2015 17:17:53 +0000 (UTC) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.14.9/8.14.9) with ESMTP id t23HHrvZ032800 for ; Tue, 3 Mar 2015 17:17:53 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 198231] [unionfs] deadlock Date: Tue, 03 Mar 2015 17:17:54 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 9.3-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: andre@fbsd.ata.myota.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: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: 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: 2.1.18-1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Mar 2015 17:17:54 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=198231 Bug ID: 198231 Summary: [unionfs] deadlock Product: Base System Version: 9.3-RELEASE Hardware: i386 OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: andre@fbsd.ata.myota.org I can reliably deadlock a 9.3-STABLE by the following procedure: Let's assume that /tmp is a standard swap-backed file system already. First let's set up what we need: mkdir /tmp/1 /tmp/2 mount -v -t unionfs /tmp/1 /usr/local mount -v -t unionfs /tmp/2 /usr/local No let's lock the system: mkdir /tmp/2/bla while :; do echo go tar -cC /usr/src/etc -f - . | tar -xpC /tmp/2/bla -f - done It survives about 3 or 4 rounds, sometimes more, sometimes only 2. It is important to use tar to copy the stuff. If we replace the tar line by e.g. cp -pR /usr/src/etc/* /tmp/2/bla things are all well. The system doesn't lock up entirely, you can move the mouse and ping it but no fs access is possible anymore. One can switch to the console and enter the debugger but a reboot with ctrl-alt-del doesn't work... The interesting part is that all this worked pretty well on 9-STABLE until approx. 2 months ago. But nothing had been committed to unionfs for a long time so I really have no idea what's going on. It also reminds us of https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=161511 but this stuff had been merged to 9-STABLE already... -- You are receiving this mail because: You are the assignee for the bug.