Allow auto-destruction of loop devices
authorDavid Woodhouse <dwmw2@infradead.org>
Wed, 6 Feb 2008 09:36:27 +0000 (01:36 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Wed, 6 Feb 2008 18:41:01 +0000 (10:41 -0800)
commit96c5865559cee0f9cbc5173f3c949f6ce3525581
treebbcfa89faeae5e5b1334a8f537b6bdb7caa992d8
parenta3b81113fb6658629f4ebaabf8dd3067cd341020
Allow auto-destruction of loop devices

This allows a flag to be set on loop devices so that when they are
closed for the last time, they'll self-destruct.

In general, so that we can automatically allocate loop devices (as with
losetup -f) and have them disappear when we're done with them.

In particular, right now, so that we can stop relying on the hackish
special-case in umount(8) which kills off loop devices which were set up by
'mount -oloop'.  That means we can stop putting crap in /etc/mtab which
doesn't belong there, which means it can be a symlink to /proc/mounts, which
means yet another writable file on the root filesystem is eliminated and the
'stateless' folks get happier...  and OLPC trac #356 can be closed.

The mount(8) side of that is at
http://marc.info/?l=util-linux-ng&m=119362955431694&w=2

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Bernardo Innocenti <bernie@codewiz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/block/loop.c
include/linux/loop.h