Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756808Ab3JHUgC (ORCPT ); Tue, 8 Oct 2013 16:36:02 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:56288 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755116Ab3JHUf4 (ORCPT ); Tue, 8 Oct 2013 16:35:56 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Miklos Szeredi Cc: "Serge E. Hallyn" , Al Viro , Linux-Fsdevel , Kernel Mailing List , Andy Lutomirski , Rob Landley , Linus Torvalds References: <87a9kkax0j.fsf@xmission.com> <8761v7h2pt.fsf@tw-ebiederman.twitter.com> <87li281wx6.fsf_-_@xmission.com> <87a9io1wu1.fsf_-_@xmission.com> <20131008135648.GH14242@tucsk.piliscsaba.szeredi.hu> Date: Tue, 08 Oct 2013 13:32:53 -0700 In-Reply-To: <20131008135648.GH14242@tucsk.piliscsaba.szeredi.hu> (Miklos Szeredi's message of "Tue, 8 Oct 2013 15:56:48 +0200") Message-ID: <87fvsby03u.fsf@tw-ebiederman.twitter.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX18fq71i12FoymvZ6IeLHYbtX9v6/C1D5IA= X-SA-Exim-Connect-IP: 98.207.154.105 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 1.5 TR_Symld_Words too many words that have symbols inside * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.5 BAYES_05 BODY: Bayes spam probability is 1 to 5% * [score: 0.0122] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa05 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Miklos Szeredi X-Spam-Relay-Country: Subject: Re: [RFC][PATCH 2/3] vfs: Add a function to lazily unmount all mounts from any dentry. X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 14:26:46 -0700) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1128 Lines: 35 Miklos Szeredi writes: > On Fri, Oct 04, 2013 at 03:43:18PM -0700, Eric W. Biederman wrote: >> >> +void detach_mounts(struct dentry *dentry) >> +{ >> + struct mount *mnt, *next; >> + struct mountpoint *mp; >> + >> + namespace_lock(); >> + if (!d_mountpoint(dentry)) { >> + namespace_unlock(); >> + return; >> + } >> + mp = new_mountpoint(dentry); >> + if (IS_ERR(mp)) { >> + return; >> + } >> + br_write_lock(&vfsmount_lock); >> + list_for_each_entry_safe(mnt, next, &mp->m_list, mnt_mp_list) { > > I don't think list_for_each_entry_safe is actually safe enough here. Because > propageted umounts will likely remove other mounts from the same mountpoint as > well. Doing it with "while (!list_empty(&mp->m_list))" should be better, and > AFAICS it will always make progress. Thanks I will take a look. But on the surface that logic sounds correct. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/