[arch-projects] [mkinitcpio][PATCH] shutdown: disassemble devices on shutdown v2

[Dave Reisner]

On Wed, Mar 28, 2012 at 11:48:48AM +0200, Thomas Bächler wrote:
> Okay, I am late to this party.

You missed all the beer and the strippers, but I sweeped up some broken
pretzels that you're welcome to.

> Am 25.03.2012 21:11, schrieb Dave Reisner:
> 
> > +    # this can sometimes fail on stopped md devices, when the
> > +    # sysfs node doesn't go away as quickly as i'd like it to.
> > +    devtype=$(lsblk -drno TYPE "/dev/$1" 2>/dev/null) || return 1
> > +    case $devtype in
> > +        crypt)
> > +            read devname <"$1/dm/name"
> > +            cryptsetup luksClose "$devname"
> > +            ;;
> 
> This should be "cryptsetup remove". Although the two are identical
> operations, the "luksClose" keyword seems to indicate that something
> LUKS-specific is happening here, which it isn't.
> 

Yup, good call.

> > +        dmraid)
> > +            # XXX: i have no idea how dmraid works
> > +            dmraid -an
> > +            ;;
> 
> 
> According to the manpage, you can use the name of the dmraid set to only
> deactivate this specific dmraid set only. Determining this name from the
> device name seems to be harder than with LVM, but I don't have any
> dmraid-capable hardware to give you specifics.

That's as far as I got... I would love to see the hierarchy under
/sys/class/block/dm* and the contents of some choice nodes from someone
who actually has this hardware.

> 
> Is there any way to make something similar work with loop devices? You
> would need to disable the loop device before umounting the underlying
> file system. If we could solve this as well, then archiso probably
> wouldn't need its special shutdown hook anymore.
> 

sure, lsblk loudly declares loop devices to be type loop. Hrmmm, archiso
does a lot of weird stuff... in particular, the squashfs mounts are
confusing me and/or lsblk. I'll get myself a newer image and poke around
at what Gerardo is doing on setup...

I'm sure it's possible, I just need to understand what's happening.

d