api_create and do_bdev_create: a few more fixes

don't use lxcpath variable for rootfs_path, it's confusing.

if rootfs is passed in and tpath is passed in, return error
before we save a new config, and don't delete the container

make sure to check c->lxc_conf is not NULL before dereferencing it.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index d882fc3ef3218c9ae719fd9a7efdb763acca561d..680b536d2760d13c163b548a86c3f94da5294000 100644 (file)
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -701,19 +701,18 @@ static struct bdev *do_bdev_create(struct lxc_container *c, const char *type,
                         struct bdev_specs *specs)
 {
        char *dest;
-       const char *lxcpath;
        size_t len;
        struct bdev *bdev;
        int ret;
 
        /* rootfs.path or lxcpath/lxcname/rootfs */
        if (c->lxc_conf->rootfs.path && access(c->lxc_conf->rootfs.path, F_OK) == 0) {
-               lxcpath = c->lxc_conf->rootfs.path;
-               len = strlen(lxcpath) + 1;
+               const char *rpath = c->lxc_conf->rootfs.path;
+               len = strlen(rpath) + 1;
                dest = alloca(len);
-               ret = snprintf(dest, len, "%s", lxcpath);
+               ret = snprintf(dest, len, "%s", rpath);
        } else {
-               lxcpath = lxcapi_get_config_path(c);
+               const char *lxcpath = lxcapi_get_config_path(c);
                len = strlen(c->name) + strlen(lxcpath) + 9;
                dest = alloca(len);
                ret = snprintf(dest, len, "%s/%s/rootfs", lxcpath, c->name);
@@ -1110,23 +1109,43 @@ static bool lxcapi_create(struct lxc_container *c, const char *t,
                }
        }
 
+       /*
+        * If a template is passed in, and the rootfs already is defined in
+        * the container config and exists, then * caller is trying to create
+        * an existing container.  Return an error, but do NOT delete the
+        * container.
+        */
+       if (lxcapi_is_defined(c) && c->lxc_conf && c->lxc_conf->rootfs.path &&
+                       access(c->lxc_conf->rootfs.path, F_OK) == 0 && tpath) {
+               ERROR("Container %s:%s already exists", c->config_path, c->name);
+               free(tpath);
+               return false;
+       }
+
+       /* Save the loaded configuration to disk */
        if (!c->save_config(c, NULL)) {
                ERROR("failed to save starting configuration for %s\n", c->name);
                goto out;
        }
 
-       /*
-        * either template or rootfs.path should be set.
-        * if both template and rootfs.path are set, template is setup as rootfs.path.
-        * container is already created if we have a config and rootfs.path is accessible
-        */
-       if (c->lxc_conf && !c->lxc_conf->rootfs.path && !tpath)
-               goto out;
-       if (c->lxc_conf->rootfs.path && access(c->lxc_conf->rootfs.path, F_OK) != 0)
-               goto out;
-       if (lxcapi_is_defined(c) && c->lxc_conf->rootfs.path && !tpath) {
-               ret = true;
-               goto out;
+       if (c->lxc_conf) {
+               /*
+                * either template or rootfs.path should be set.
+                * if both template and rootfs.path are set, template is setup as rootfs.path.
+                * container is already created if we have a config and rootfs.path is accessible
+                */
+               if (!c->lxc_conf->rootfs.path && !tpath)
+                       /* no template passed in and rootfs does not exist: error */
+                       goto out;
+               if (c->lxc_conf->rootfs.path && access(c->lxc_conf->rootfs.path, F_OK) != 0)
+                       /* rootfs passed into configuration, but does not exist: error */
+                       goto out;
+               if (lxcapi_is_defined(c) && c->lxc_conf->rootfs.path && !tpath) {
+                       /* Rootfs already existed, user just wanted to save the
+                        * loaded configuration */
+                       ret = true;
+                       goto out;
+               }
        }
 
        /* Mark that this container is being created */