Re: umount(/proc) after CLONE_NEWNS in 2.6.25?

From: Michael Tokarev
Date: Tue Apr 29 2008 - 00:37:17 EST


Al Viro wrote:
On Tue, Apr 29, 2008 at 03:06:38AM +0100, Al Viro wrote:

Check the version of umount(8) you've got. And see if that strace happens
to have open of /proc/mounts, without matching close by the time it calls
umount(). util-linux-ng 2.13.1 is _that_ dumb...
Umm... Looks like something more odd is going on...

... or something much simpler:

; cat /proc/mounts |grep proc
proc /proc proc rw,nosuid,nodev,noexec 0 0
usbfs /proc/bus/usb usbfs rw 0 0
;

and unmounting the stuff mounted under /proc before doing umount /proc
works as expected. Amazing how well the first cup of coffee helps...

Hey. Don't paint ME *that* dumb... ;)

It was indeed the case here. I never tried those things on my
home machine before, and decided to experiment, but I forgot
that it has /proc/bus/usb mounted. And for comparison I used
another machine which does NOT have that filesystem mounted.
How.. dum^Wodd... ;)

Please excuse me for the noise.

/mj
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/