Gentoo Archives: gentoo-dev

From: Luca Barbato <lu_zero@g.o>
To: gentoo-dev@l.g.o
Subject: Re: [gentoo-dev] rfc: Does OpenRC really need mount-ro
Date: Wed, 17 Feb 2016 08:25:12
Message-Id: f3c23737-b774-c979-fbba-95c509642c9c@gentoo.org
In Reply to: [gentoo-dev] rfc: Does OpenRC really need mount-ro by William Hubbs
1 On 16/02/16 19:05, William Hubbs wrote:
2 > All,
3 >
4 > I have a bug that points out a significant issue with
5 > /etc/init.d/mount-ro in OpenRC.
6 >
7 > Apparently, there are issues that cause it to not work properly for file
8 > systems which happen to be pre-mounted from an initramfs [1].
9
10 Who is using that file system? Ideally if "we" are the last user of the
11 file system it should be safe to mount ro it as well.
12
13 In general this happens when there is a "too smart to fit /" filesystem
14 in use.
15
16 In general that means that the same stuff used in /usr to mount it
17 should live in the initrd...
18
19 In general deprecating split-/usr moves the problem in in supporting fat
20 initrds to begin with. (I guess needing a boot filesystem that is fuse
21 based and needs rabbitmq or postgresql might be extra fun btw).
22
23 > This service only exists in the Linux world; there is no equivalent in
24 > OpenRC for any other operating systems we support.
25
26 Given it is a safety feature I do not know how the other kernels achieve
27 the same out of box.
28
29 > The reason it exists is very vague to me; I think it has something to do
30 > with claims of data loss in the past.
31
32 I think any fuse-supporting system should have it for more or less
33 obvious reasons (see the evil example above).
34
35 lu