/dev/root (was: Re: Partitioned raid and major number)

On 2004.03.01 01:54, Neil Brown wrote:

On Saturday February 28, miquels@cistron.nl wrote:

quoted

Hmm. With a dynamic major, the system might fail at checking the root
file system at boot. At that time, /dev is still read-only, and
/dev/md/d0p1 might not be the correct device yet.

So either mdp needs its own partition number, or we need a /dev/root
device that's an alias for the current root (like /dev/console).

Yes, I think this is a real problem.
There are a number of avenues that could be followed to fix it.
One it your suggestion.

Another is to make "rootfs" remountable

And then:

  mount -t rootfs rootfs /mnt/root
  fsck /mnt/root/dev/root

Another is to add "rootdev" to /proc/*, as in appended patch. Then
  ln -s /proc/self/roodev /dev/root

and providing /proc is mounted, /dev/root will work.

I might try to push it on linux-kernel.

Mind if I post all three approaches (/dev/root alias device, rootfs, /proc/pid/root)
to linux-kernel and ask input on what approach is the preferred one ?

Mike.