From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757406Ab0KOBbV (ORCPT ); Sun, 14 Nov 2010 20:31:21 -0500 Received: from out3.smtp.messagingengine.com ([66.111.4.27]:39882 "EHLO out3.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757326Ab0KOBbU (ORCPT ); Sun, 14 Nov 2010 20:31:20 -0500 X-Sasl-enc: vpsMsZdSOhsgcD9FDF81hq2xiWd+pfObRzLoeyZaSeRN 1289784679 Subject: Re: autofs4 hang in 2.6.37-rc1 From: Ian Kent To: Arnd Bergmann Cc: Avi Kivity , autofs@linux.kernel.org, linux-kernel In-Reply-To: <201011141615.32166.arnd@arndb.de> References: <4CDFDC2B.6040205@redhat.com> <4CDFE948.4020709@redhat.com> <201011141615.32166.arnd@arndb.de> Content-Type: text/plain; charset="UTF-8" Date: Mon, 15 Nov 2010 09:31:14 +0800 Message-ID: <1289784674.3248.11.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 (2.28.3-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2010-11-14 at 16:15 +0100, Arnd Bergmann wrote: > On Sunday 14 November 2010 14:51:04 Avi Kivity wrote: > > automount S ffff88012a28a680 0 399 1 0x00000000 > > ffff88012a07bd08 0000000000000082 0000000000000000 0000000000000000 > > ffff88012a07a010 ffff88012a07bfd8 0000000000011800 ffff88012693c260 > > ffff88012693c5d0 ffff88012693c5c8 0000000000011800 0000000000011800 > > Call Trace: > > [] ? prepare_to_wait+0x67/0x74 > > [] autofs4_wait+0x5a4/0x6d5 > > [] ? autoremove_wake_function+0x0/0x34 > > [] autofs4_do_expire_multi+0x5b/0xa3 > > [] autofs4_expire_multi+0x4c/0x54 > > [] autofs4_root_ioctl_unlocked+0x23e/0x252 > > [] autofs4_root_ioctl+0x39/0x53 > > [] do_vfs_ioctl+0x557/0x5bb > > [] ? remove_vma+0x6e/0x76 > > [] ? do_munmap+0x31c/0x33e > > [] sys_ioctl+0x42/0x65 > > [] system_call_fastpath+0x16/0x1b > > > > > > Shouldn't we drop autofs4_ioctl_mutex while we wait? > > If the ioctl can sleep for multiple seconds, the mutex should > indeed be dropped, and that would be safe because we used to > do the same with the BKL. > > The question is why this would sleep for more than 120 seconds. umount against a server that isn't responding can easily take more than 2 minutes. Ian