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>
diff --git a/include/linux/loop.h b/include/linux/loop.h
index 26a0a10..46169a7 100644
--- a/include/linux/loop.h
+++ b/include/linux/loop.h
@@ -76,6 +76,7 @@
enum {
LO_FLAGS_READ_ONLY = 1,
LO_FLAGS_USE_AOPS = 2,
+ LO_FLAGS_AUTOCLEAR = 4,
};
#include <asm/posix_types.h> /* for __kernel_old_dev_t */