[libvirt] [PATCH v2 5/8] LXC: Creating devices for container on host side
Gao feng
gaofeng at cn.fujitsu.com
Fri May 10 09:58:14 UTC 2013
user namespace doesn't allow to create devices in
uninit userns. We should create devices on host side.
Signed-off-by: Gao feng <gaofeng at 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_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;
+
+ if (lxcContainerSendContinue(control[0]) < 0) {
+ virReportSystemError(errno, "%s",
+ _("Unable to send container continue message"));
+ goto cleanup;
+ }
+
/* Now the container is fully setup... */
/* ...and reduce our privileges */
--
1.8.1.4
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