From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Lord <kernel@teksavvy.com>
Subject: Re: [PATCH] Syscalls: reboot: Add options to the reboot syscall to
 remount filesystems ro
Date: Thu, 03 Mar 2011 13:28:01 -0500
Message-ID: <4D6FDDB1.3060209@teksavvy.com>
References: <1299137483-10975-1-git-send-email-ksumrall@android.com> <AANLkTik1pNPzPqXaNrLNFnEt4+cknxYdOUwZ9Q=g5PCA@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Cc: Ken Sumrall <ksumrall@android.com>, linux-kernel@vger.kernel.org,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Christoph Hellwig <hch@lst.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jan Kara <jack@suse.cz>, Jens Axboe <axboe@kernel.dk>,
	Matthew Wilcox <matthew@wil.cx>,
	Eric Paris <eparis@redhat.com>,
	Dave Young <hidave.darkstar@gmail.com>,
	Jiri Slaby <jslaby@suse.cz>, James Morris <jmorris@namei.org>,
	linux-fsdevel@vger.kernel.org
To: Linus Torvalds <torvalds@linux-foundation.org>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <AANLkTik1pNPzPqXaNrLNFnEt4+cknxYdOUwZ9Q=g5PCA@mail.gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

On 11-03-03 12:45 PM, Linus Torvalds wrote:
>
> If you can change whatever user-land process that does the reboot
> system call (and clearly you can, since you're adding new commands and
> using those), then why the heck don't you just do the remount-ro from
> that same user land?

Is there a system call for emergency_remount_*() ?
I've been writing to /proc/proc/sysrq-trigger to accomplish this.