On Fri, May 10, 2013 at 05:58:14PM +0800, Gao feng wrote:
user namespace doesn't allow to create devices in uninit userns. We should create devices on host side.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> --- src/lxc/lxc_container.c | 47 +++++++---------------------- src/lxc/lxc_controller.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 87 insertions(+), 37 deletions(-)
diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index e9b90bf..2072e9a 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c @@ -1103,6 +1103,73 @@ cleanup: }
+static int virLXCControllerPopulateDevices(virLXCControllerPtr ctrl) +{ + size_t i; + int ret = -1; + char *ptmx = NULL; + char *path = NULL; + const struct { + int maj; + int min; + mode_t mode; + const char *path; + } devs[] = { + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_NULL, 0666, "/dev/null" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_ZERO, 0666, "/dev/zero" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_FULL, 0666, "/dev/full" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_RANDOM, 0666, "/dev/random" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_URANDOM, 0666, "/dev/urandom" }, + }; + + /* Populate /dev/ with a few important bits */ + for (i = 0 ; i < ARRAY_CARDINALITY(devs) ; i++) { + if (virAsprintf(&path, "/proc/%llu/root/%s", + (unsigned long long)ctrl->initpid, + devs[i].path) < 0) { + virReportOOMError(); + goto out; + } + + dev_t dev = makedev(devs[i].maj, devs[i].min); + if (mknod(path, S_IFCHR, dev) < 0 || + chmod(path, devs[i].mode)) { + virReportSystemError(errno, + _("Failed to make device %s"), + devs[i].path); + goto out; + } + } + + if (virAsprintf(&ptmx, "/proc/%llu/root/dev/pts/ptmx", + (unsigned long long)ctrl->initpid) < 0) { + virReportOOMError();
It is really non-obvious that this code is not being run until the container has started. IMHO rather than playing games with the /proc/$PID/root/dev link, you should make the lxc_controller.c code responsible for mounting the /dev tmpfs somewhere, and populate it before any of the lxc_container code even runs. Then the lxc_container code can simply MS_MOVE the pre-populate /dev to the right place when it starts. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|