linux-kernel - Re: 2.6.26-mmotm-0724 - linux-next.git loses /proc/sys/fs/quota, breaks disk quotas

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20080726202525.3ac3052f.akpm@linux-foundation.org>
Date:	Sat, 26 Jul 2008 20:25:25 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Valdis.Kletnieks@...edu
Cc:	linux-kernel@...r.kernel.org, Jan Kara <jack@....cz>,
	Al Viro <viro@...iv.linux.org.uk>
Subject: Re: 2.6.26-mmotm-0724 - linux-next.git loses /proc/sys/fs/quota,
 breaks disk quotas

On Sat, 26 Jul 2008 22:22:46 -0400 Valdis.Kletnieks@...edu wrote:

> I bisected the problem to somewhere in here:
> 
> repeatable-slab-corruption-with-ltp-msgctl08.patch GOOD
> #
> linux-next.patch
> linux-next-git-rejects.patch
> linux-next-fixup.patch BAD
> 
> I have no idea how to go bisecting through linux-next.patch

You need to grab the git tree and use git-bisect.  Then wade through
all the runtime and compile-time bisection breakage which people
nowadays seem to find acceptable because git collapses in an
ignominious heap when these are fixed.

> It works in 26-mmotm-0715, but is broken in -0724, so that will hopefully
> narrow the suspect commits down a *little* bit...
> 
> The problem is that the userspace does this:
> 
>         /* Detect new kernel interface; Assume generic interface unless we can p
> rove there is not one... */
>         if (!stat("/proc/sys/fs/quota", &st) || errno != ENOENT) {
>                 kernel_iface = IFACE_GENERIC;
>                 kernel_formats |= (1 << QF_VFSOLD) | (1 << QF_VFSV0);
>         }
>         else {
>                 struct v2_dqstats v2_stats;
> 
> and /proc/sys/fs/quota has mysteriously vanished in -0724. As a result,
> the userspace code goes looking for the quotav1 files and doesn't find them,
> since the actual files on disk are quotav2 (with a different name).
> 
> fs/dquot.c, which contains the code for that, appears to be identical in -0715
> and -0724, so something *else* is breaking it.
> 
> Anybody know where /proc/sys/fs/quota went?
> 

Nope.  There are pretty extensive changes to procfs core in the vfs
tree - perhaps something there made /proc/sys/fs/quota vanish.

<checks>

Yup, it happens in the most recent linux-next too.

Ah, it seems to be taking a little vacation over in
/proc/sys/kernel/.  Curious.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/