From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756164AbYG0FRS (ORCPT ); Sun, 27 Jul 2008 01:17:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751886AbYG0FRG (ORCPT ); Sun, 27 Jul 2008 01:17:06 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:43587 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750935AbYG0FRF (ORCPT ); Sun, 27 Jul 2008 01:17:05 -0400 Date: Sun, 27 Jul 2008 06:17:02 +0100 From: Al Viro To: Valdis.Kletnieks@vt.edu Cc: Andrew Morton , linux-kernel@vger.kernel.org, Jan Kara , Linus Torvalds Subject: [PATCH] Re: 2.6.26-mmotm-0724 - linux-next.git loses /proc/sys/fs/quota, breaks disk quotas Message-ID: <20080727051702.GY28946@ZenIV.linux.org.uk> References: <14615.1217125366@turing-police.cc.vt.edu> <20080726202525.3ac3052f.akpm@linux-foundation.org> <21657.1217130229@turing-police.cc.vt.edu> <20080727040908.GX28946@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080727040908.GX28946@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 27, 2008 at 05:09:08AM +0100, Al Viro wrote: > On Sat, Jul 26, 2008 at 11:43:49PM -0400, Valdis.Kletnieks@vt.edu wrote: > > > > Ah, it seems to be taking a little vacation over in > > > /proc/sys/kernel/. Curious. > > > > Wow. I never *thought* to look for it there, and neither did my userspace :) > > Wow, indeed... Very odd, since there shouldn't be any way for that > to end up there. Off to try and reproduce it... Wait... I remember fixing exactly that, but the fix is not in there... Bugger. Botched "fold on reorder", fortunately still findable in old local branch. Anyway, I know what's going on; will test in a few, but I'm fairly sure what it is. The lost fix is to have try_attach() walk into the right subdirectory of what we are attaching, not the first one. Fun with reordering ;-/ The missing delta, rediffed to the tip of Linus' tree follows and definitely needs to be applied; will test if that's all there is as soon as the kernel build finishes... Sigh... Why does that stuff show up after 10 days in linux-next, about 5 minutes after seeing it merged into mainline? Murphy's fun... diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 911d846..fe47133 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1680,43 +1680,45 @@ static __init int sysctl_init(void) core_initcall(sysctl_init); -static int is_branch_in(struct ctl_table *branch, struct ctl_table *table) +static struct ctl_table *is_branch_in(struct ctl_table *branch, + struct ctl_table *table) { struct ctl_table *p; const char *s = branch->procname; /* branch should have named subdirectory as its first element */ if (!s || !branch->child) - return 0; + return NULL; /* ... and nothing else */ if (branch[1].procname || branch[1].ctl_name) - return 0; + return NULL; /* table should contain subdirectory with the same name */ for (p = table; p->procname || p->ctl_name; p++) { if (!p->child) continue; if (p->procname && strcmp(p->procname, s) == 0) - return 1; + return p; } - return 0; + return NULL; } /* see if attaching q to p would be an improvement */ static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) { struct ctl_table *to = p->ctl_table, *by = q->ctl_table; + struct ctl_table *next; int is_better = 0; int not_in_parent = !p->attached_by; - while (is_branch_in(by, to)) { + while ((next = is_branch_in(by, to)) != NULL) { if (by == q->attached_by) is_better = 1; if (to == p->attached_by) not_in_parent = 1; by = by->child; - to = to->child; + to = next->child; } if (is_better && not_in_parent) {