Re: [libvirt] [PATCH v3 05/12] LXC: Creating devices for container on host side

user namespace doesn't allow to create devices in uninit userns. We should create devices on host side. We first mount tmpfs on dev directroy under state dir of container. then create devices under this dev dir. Finally in container, mount the dev directroy created on host to the /dev/ directroy of container. Signed-off-by: Gao feng <gaofeng(a)cn.fujitsu.com&gt; --- src/lxc/lxc_container.c | 96 +++++++++++++--------------------- src/lxc/lxc_controller.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 166 insertions(+), 60 deletions(-) @@ -903,15 +884,6 @@ static int lxcContainerPopulateDevices(char **ttyPaths, size_t nttyPaths) _("Failed to bind /dev/pts/ptmx on to /dev/ptmx")); return -1; } - } else { - /* Legacy devpts, so we need to just use shared one */ - dev_t dev = makedev(LXC_DEV_MAJ_TTY, LXC_DEV_MIN_PTMX); - if (mknod("/dev/ptmx", S_IFCHR, dev) < 0 || - chmod("/dev/ptmx", 0666)) { - virReportSystemError(errno, "%s", - _("Failed to make device /dev/ptmx")); - return -1; - } }

diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index 0a2e3ac..e9808f3 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c +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, "/null" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_ZERO, 0666, "/zero" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_FULL, 0666, "/full" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_RANDOM, 0666, "/random" }, + { LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_URANDOM, 0666, "/urandom" }, + }; + + if (virLXCControllerSetupDev(ctrl) < 0) + goto out; + + /* Populate /dev/ with a few important bits */ + for (i = 0 ; i < ARRAY_CARDINALITY(devs) ; i++) { + if (virAsprintf(&path, "/%s/%s.dev/%s", + LXC_STATE_DIR, ctrl->def->name, + 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; + } + VIR_FREE(path); + } + + if (virAsprintf(&ptmx, "/%s/%s.devpts/ptmx", + LXC_STATE_DIR, ctrl->def->name) < 0) { + virReportOOMError(); + goto out; + } + + if (access(ptmx, W_OK)) { + if (virAsprintf(&path, "/%s/%s.dev/ptmx", + LXC_STATE_DIR, ctrl->def->name)) { + virReportOOMError(); + goto out; + } + /* Legacy devpts, so we need to just use shared one */ + dev_t dev = makedev(LXC_DEV_MAJ_TTY, LXC_DEV_MIN_PTMX); + if (mknod(path, S_IFCHR, dev) < 0 || + chmod(path, 0666)) { + virReportSystemError(errno, _("Failed to make device %s"), path); + goto out; + }