Re: [libvirt] [PATCH v2 5/8] 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. Signed-off-by: Gao feng <gaofeng(a)cn.fujitsu.com&gt; --- 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_container.c b/src/lxc/lxc_container.c index eabaa34..540246f 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -833,22 +833,10 @@ cleanup: return ret; } -static int lxcContainerPopulateDevices(char **ttyPaths, size_t nttyPaths) +static int lxcContainerSetupDevices(char **ttyPaths, size_t nttyPaths) { size_t i; 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" }, - }; - const struct { const char *src; const char *dst; } links[] = { @@ -858,18 +846,6 @@ static int lxcContainerPopulateDevices(char **ttyPaths, size_t nttyPaths) { "/proc/self/fd", "/dev/fd" }, }; - /* Populate /dev/ with a few important bits */ - for (i = 0 ; i < ARRAY_CARDINALITY(devs) ; i++) { - dev_t dev = makedev(devs[i].maj, devs[i].min); - if (mknod(devs[i].path, S_IFCHR, dev) < 0 || - chmod(devs[i].path, devs[i].mode)) { - virReportSystemError(errno, - _("Failed to make device %s"), - devs[i].path); - return -1; - } - } - for (i = 0 ; i < ARRAY_CARDINALITY(links) ; i++) { if (symlink(links[i].src, links[i].dst) < 0) { virReportSystemError(errno, @@ -882,22 +858,13 @@ static int lxcContainerPopulateDevices(char **ttyPaths, size_t nttyPaths) if (access("/dev/pts/ptmx", W_OK) == 0) { /* We have private devpts capability, so bind that */ if (virFileTouch("/dev/ptmx", 0666) < 0) - return -1; + return -1; if (mount("/dev/pts/ptmx", "/dev/ptmx", "ptmx", MS_BIND, NULL) < 0) { virReportSystemError(errno, "%s", _("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; - } } for (i = 0 ; i < nttyPaths ; i++) { @@ -1825,8 +1792,8 @@ static int lxcContainerSetupPivotRoot(virDomainDefPtr vmDef, if (lxcContainerMountFSDevPTS(vmDef, "/.oldroot") < 0) goto cleanup; - /* Populates device nodes in /dev/ */ - if (lxcContainerPopulateDevices(ttyPaths, nttyPaths) < 0) + /* Sets up device nodes in /dev/ */ + if (lxcContainerSetupDevices(ttyPaths, nttyPaths) < 0) goto cleanup; /* Sets up any non-root mounts from guest config */ @@ -2037,6 +2004,12 @@ static int lxcContainerChild(void *data) goto cleanup; } + if (lxcContainerWaitForContinue(argv->monitor) < 0) { + virReportSystemError(errno, "%s", + _("Failed to read the container continue message")); + goto cleanup; + } + ret = 0; cleanup: VIR_FREE(ttyPath); 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(); + goto out; + } + + if (access(ptmx, W_OK)) { + VIR_FREE(path); + + if (virAsprintf(&path, "/proc/%llu/root/dev/ptmx", + (unsigned long long)ctrl->initpid) < 0) { + 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; + } + } + + ret = 0; +out: + VIR_FREE(ptmx); + VIR_FREE(path); + return ret; +} /** * virLXCControllerMoveInterfaces @@ -1552,6 +1619,16 @@ virLXCControllerRun(virLXCControllerPtr ctrl) goto cleanup; } + /* Populate devices for container */ + if (virLXCControllerPopulateDevices(ctrl) < 0) + goto cleanup;