From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756420Ab3JHUey (ORCPT ); Tue, 8 Oct 2013 16:34:54 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:55518 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754418Ab3JHUeu (ORCPT ); Tue, 8 Oct 2013 16:34:50 -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> <87fvsg1wv6.fsf_-_@xmission.com> <20131008134453.GG14242@tucsk.piliscsaba.szeredi.hu> Date: Tue, 08 Oct 2013 13:31:45 -0700 In-Reply-To: <20131008134453.GG14242@tucsk.piliscsaba.szeredi.hu> (Miklos Szeredi's message of "Tue, 8 Oct 2013 15:44:53 +0200") Message-ID: <87li23y05q.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: U2FsdGVkX1+wuGYIVd97zIDVXW7oN+gatWMDAPh4RCI= 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: 0.0287] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Miklos Szeredi X-Spam-Relay-Country: Subject: Re: [RFC][PATCH 1/3] vfs: Keep a list of mounts on a mount point 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 in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Miklos Szeredi writes: >> @@ -691,6 +693,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path) >> list_del_init(&mnt->mnt_hash); >> put_mountpoint(mnt->mnt_mp); >> mnt->mnt_mp = NULL; >> + list_del_init(&mnt->mnt_mp_list); > > Should be done *before* put_mountpoint(), for obvious reasons. > > And a BUG_ON(!list_empty(&mp->m_list)) in put_mountpoint() for good measure (and > no, WARN_ON() is not better here, since use-after-free is definitely worse than > a BUG). Good point. I will take a look at making this change shortly and repost the patches. >> } >> >> /* >> @@ -705,6 +708,7 @@ void mnt_set_mountpoint(struct mount *mnt, >> child_mnt->mnt_mountpoint = dget(mp->m_dentry); >> child_mnt->mnt_parent = mnt; >> child_mnt->mnt_mp = mp; >> + list_add_tail(&child_mnt->mnt_mp_list, &mp->m_list); >> } >> >> /* >> @@ -1193,6 +1197,7 @@ void umount_tree(struct mount *mnt, int propagate) >> p->mnt_parent->mnt_ghosts++; >> put_mountpoint(p->mnt_mp); >> p->mnt_mp = NULL; >> + list_del_init(&mnt->mnt_mp_list); > > Ditto. > >> } >> change_mnt_propagation(p, MS_PRIVATE); >> } >> -- >> 1.7.5.4 >>