Subject: Re: devfs, was Re: ptyfs fully working now...
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 11/13/2004 00:57:46
>> The first problem is solved by a devfs layer that, before returning
>> any device inode, verifies that it exists in the running system.
> How about putting one more odd kink in it?  The drivers don't create
> the nodes on disk, they just appear magically in devfs as you would
> expect.  But when you chmod/chown/etc. any of them, *then* a shadow
> entry is created on the disk beneath the mount point (sort of like a
> union fs upside down) and the owner/mode replicated there.

What about "mv /dev/lpt1 /dev/spinner", how does that get represented
in the on-disk layer?  Presumably a whiteout is created to hide
/dev/lpt1, but what happens for /dev/spinner?

What about

# mv /dev/tty00 /dev/foo
# mv /dev/tty01 /dev/tty00
# mv /dev/foo /dev/tty01

how does that get represented?  (Yes, such things have their uses.)

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