Re: [PATCH] change Kconfig entry for RAMFS

From: Grzegorz Kulewski
Date: Wed Nov 10 2004 - 05:42:05 EST


On Tue, 9 Nov 2004, Matt Mackall wrote:

On Sat, Nov 06, 2004 at 12:44:14AM +0100, Grzegorz Kulewski wrote:
So at the very least you'd need to make the Kconfig understand the
dependency on ramfs.

Should I add dependency to tmpfs on ramfs when building for embedded? Or
should I introduce new config option to stop registering ramfs as a
mountable filesystem?

Root is ramfs at early boot time, making it optional is tricky.

You mean it is

rootfs / rootfs rw 0 0

in my /proc/mounts? Why this can not be tmpfs on normal dektop or server machines?

I have two goals in removing ramfs:
- stop user or distribution from mounting it somewhere to avoid strange oom panics when, by some unkown reason, something writes more data on it than RAM in the box,
- maybe construct / on tmpfs (from initramfs => "inittmpfs") in the future. Then ramfs will mount all needed filesystem (possibly from net or some sophisticated compressed / encrypted / raid volumes. But I will want / on tmpfs to stay, just mount --bind /mnt/root/bin /bin and the same for other / directories. This way I can mount /proc, /sys, create /dev for udev and so on once, and I think this is simpler than mounting some real fs latter on / or using pivot_root. This way I can survive some serious fs problems on real disk / because I can umount it (maybe in single mode) and run some fs checker from my inittmpfs on it. I do not want to use ramfs for that because it can oom when some program or I will write big file to /.

I really do not understand why we need ramfs on not embedded boxes. If we can not remove its code then at least make in impossible to mount. But that is only my opinion.


Thanks,

Grzegorz Kulewski

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