Hi there, > No. There's a change there, all right, and thank you for reminding > me > of that, but (afaik) it's NOT in the kernel itself. It's a mount > option. It's that bloody MS_SHARED option and, to a lessor extent, > MS_SLAVE option that are behind how those things are propagated. > MS_SHARED will propagate certain things from a child mount to the > mount > point and to other children, IIRC, while MS_SLAVE propagates in one > direction and MS_PRIVATE restricts it. I think the trouble maker is > MS_SHARED and that's what caused all the "pivot_root" calls to face > plant when systemd started mounting everything with MS_SHARED in the > host system. I was using bind mounts to avoid some of these problems > but then they changed systemd and its default mount options and broke > a > number of things I had running.
This is not MS_SHARED. The 3.8 instance I'm testing this with is a Debian Wheezy with a custom kernel (the 3.8 from Serge's and/or Stéphane's repository for userns which floated around here half a year ago or so. (I never had a chance to upgrade, it's in a KVM, so that I don't break my main system). Look at the following: root@lxcdev:~# mkdir /foo/bar /foo/baz -p root@lxcdev:~# mount --bind /foo/bar /foo/baz root@lxcdev:~# grep /foo /proc/self/mountinfo 25 20 253:1 /foo/bar /foo/baz rw,relatime - ext4 /dev/disk/by-uuid/b2e1ac13-e6d0-48e7-a3b0-9fcdf81db294 rw,errors=remount-ro,data=ordered root@lxcdev:~# grep ^20 /proc/self/mountinfo 20 1 253:1 / / rw,relatime - ext4 /dev/disk/by-uuid/b2e1ac13-e6d0-48e7-a3b0-9fcdf81db294 rw,errors=remount-ro,data=ordered root@lxcdev:~# mount /foo/baz -o remount,ro mount: /foo/baz is busy root@lxcdev:~# mount /foo/baz -o remount,bind,ro root@lxcdev:~# grep /foo /proc/self/mountinfo 25 20 253:1 /foo/bar /foo/baz ro,relatime - ext4 /dev/disk/by-uuid/b2e1ac13-e6d0-48e7-a3b0-9fcdf81db294 rw,errors=remount-ro,data=ordered root@lxcdev:~# uname -a Linux lxcdev 3.8.0-rc3+ #1 SMP Sun Jan 27 16:39:34 CET 2013 x86_64 GNU/Linux I don't see any shared: in /proc/self/mountinfo. Obviously, this could be a side-effect of the specific kernel I'm using, but I don't recall the additional userns patches to change anything in that regard. Also note that a mount --make-private / doesn't change anything. And that this isn't even in an own namespace. I don't have that much time atm, so I won't be able to check with a current official kernel. -- Christian ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60133471&iu=/4140/ostg.clktrk _______________________________________________ Lxc-devel mailing list Lxc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lxc-devel
