[lxc-devel] [PATCH 2/1] btrfs: support unprivileged destroy
Serge Hallyn
serge.hallyn at ubuntu.com
Tue May 6 21:43:19 UTC 2014
Do this by calling the bdev->destroy() hook from a user namespace
configured as the container's.
Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
---
src/lxc/lxccontainer.c | 50 ++++++++++++++++++++++++++++++++++++++----------
1 file changed, 40 insertions(+), 10 deletions(-)
diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 9e23c7b..255fde5 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -1987,10 +1987,41 @@ static int lxc_rmdir_onedev_wrapper(void *data)
return lxc_rmdir_onedev(arg);
}
+static int do_bdev_destroy(struct lxc_conf *conf)
+{
+ struct bdev *r;
+ int ret = 0;
+
+ r = bdev_init(conf->rootfs.path, conf->rootfs.mount, NULL);
+ if (!r)
+ return -1;
+
+ if (r->ops->destroy(r) < 0)
+ ret = -1;
+ bdev_put(r);
+ return ret;
+}
+
+static int bdev_destroy_wrapper(void *data)
+{
+ struct lxc_conf *conf = data;
+
+ if (setgid(0) < 0) {
+ ERROR("Failed to setgid to 0");
+ return -1;
+ }
+ if (setgroups(0, NULL) < 0)
+ WARN("Failed to clear groups");
+ if (setuid(0) < 0) {
+ ERROR("Failed to setuid to 0");
+ return -1;
+ }
+ return do_bdev_destroy(conf);
+}
+
// do we want the api to support --force, or leave that to the caller?
static bool lxcapi_destroy(struct lxc_container *c)
{
- struct bdev *r = NULL;
bool bret = false;
int ret;
@@ -2011,15 +2042,14 @@ static bool lxcapi_destroy(struct lxc_container *c)
goto out;
}
- if (!am_unpriv() && c->lxc_conf && c->lxc_conf->rootfs.path && c->lxc_conf->rootfs.mount) {
- r = bdev_init(c->lxc_conf->rootfs.path, c->lxc_conf->rootfs.mount, NULL);
- if (r) {
- if (r->ops->destroy(r) < 0) {
- bdev_put(r);
- ERROR("Error destroying rootfs for %s", c->name);
- goto out;
- }
- bdev_put(r);
+ if (c->lxc_conf && c->lxc_conf->rootfs.path && c->lxc_conf->rootfs.mount) {
+ if (am_unpriv())
+ ret = userns_exec_1(c->lxc_conf, bdev_destroy_wrapper, c->lxc_conf);
+ else
+ ret = do_bdev_destroy(c->lxc_conf);
+ if (ret < 0) {
+ ERROR("Error destroying rootfs for %s", c->name);
+ goto out;
}
}
--
1.7.9.5
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