Merge pull request #2435 from brauner/2018-06-27/storage_managed

[RFC] conf: introduce lxc.rootfs.managed

src/lxc/conf.c

@@ -2769,6 +2769,7 @@ struct lxc_conf *lxc_conf_init(void)
 		free(new);
 		return NULL;
 	}
+	new->rootfs.managed = true;
 	new->logfd = -1;
 	lxc_list_init(&new->cgroup);
 	lxc_list_init(&new->cgroup2);

src/lxc/conf.h

@@ -159,6 +159,7 @@ struct lxc_tty_info {
  * @options    : mount options
  * @mountflags : the portion of @options that are flags
  * @data       : the porition of @options that are not flags
+ * @managed    : whether it is managed by LXC
  */
 struct lxc_rootfs {
 	char *path;
@@ -167,6 +168,7 @@ struct lxc_rootfs {
 	char *options;
 	unsigned long mountflags;
 	char *data;
+	bool managed;
 };
 
 /*

src/lxc/confile.c

@@ -142,6 +142,7 @@ lxc_config_define(no_new_privs);
 lxc_config_define(personality);
 lxc_config_define(prlimit);
 lxc_config_define(pty_max);
+lxc_config_define(rootfs_managed);
 lxc_config_define(rootfs_mount);
 lxc_config_define(rootfs_options);
 lxc_config_define(rootfs_path);
@@ -228,6 +229,7 @@ static struct lxc_config_t config[] = {
 	{ "lxc.no_new_privs",	           set_config_no_new_privs,                get_config_no_new_privs,                clr_config_no_new_privs,              },
 	{ "lxc.prlimit",                   set_config_prlimit,                     get_config_prlimit,                     clr_config_prlimit,                   },
 	{ "lxc.pty.max",                   set_config_pty_max,                     get_config_pty_max,                     clr_config_pty_max,                   },
+	{ "lxc.rootfs.managed",            set_config_rootfs_managed,              get_config_rootfs_managed,              clr_config_rootfs_managed,            },
 	{ "lxc.rootfs.mount",              set_config_rootfs_mount,                get_config_rootfs_mount,                clr_config_rootfs_mount,              },
 	{ "lxc.rootfs.options",            set_config_rootfs_options,              get_config_rootfs_options,              clr_config_rootfs_options,            },
 	{ "lxc.rootfs.path",               set_config_rootfs_path,                 get_config_rootfs_path,                 clr_config_rootfs_path,               },
@@ -2162,6 +2164,31 @@ static int set_config_rootfs_path(const char *key, const char *value,
 	return ret;
 }
 
+static int set_config_rootfs_managed(const char *key, const char *value,
+				     struct lxc_conf *lxc_conf, void *data)
+{
+	unsigned int val = 0;
+
+	if (lxc_config_value_empty(value)) {
+		lxc_conf->rootfs.managed = true;
+		return 0;
+	}
+
+	if (lxc_safe_uint(value, &val) < 0)
+		return -EINVAL;
+
+	switch (val) {
+	case 0:
+		lxc_conf->rootfs.managed = false;
+		return 0;
+	case 1:
+		lxc_conf->rootfs.managed = true;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
 static int set_config_rootfs_mount(const char *key, const char *value,
 				   struct lxc_conf *lxc_conf, void *data)
 {
@@ -3390,6 +3417,12 @@ static int get_config_rootfs_path(const char *key, char *retv, int inlen,
 	return lxc_get_conf_str(retv, inlen, c->rootfs.path);
 }
 
+static int get_config_rootfs_managed(const char *key, char *retv, int inlen,
+				     struct lxc_conf *c, void *data)
+{
+	return lxc_get_conf_bool(c, retv, inlen, c->rootfs.managed);
+}
+
 static int get_config_rootfs_mount(const char *key, char *retv, int inlen,
 				   struct lxc_conf *c, void *data)
 {
@@ -4016,6 +4049,13 @@ static inline int clr_config_rootfs_path(const char *key, struct lxc_conf *c,
 	return 0;
 }
 
+static inline int clr_config_rootfs_managed(const char *key, struct lxc_conf *c,
+					    void *data)
+{
+	c->rootfs.managed = true;
+	return 0;
+}
+
 static inline int clr_config_rootfs_mount(const char *key, struct lxc_conf *c,
 					  void *data)
 {

src/lxc/confile_utils.c

@@ -672,6 +672,21 @@ int lxc_get_conf_str(char *retv, int inlen, const char *value)
 	return value_len;
 }
 
+int lxc_get_conf_bool(struct lxc_conf *c, char *retv, int inlen, bool v)
+{
+	int len;
+	int fulllen = 0;
+
+	if (!retv)
+		inlen = 0;
+	else
+		memset(retv, 0, inlen);
+
+	strprint(retv, inlen, "%d", v);
+
+	return fulllen;
+}
+
 int lxc_get_conf_int(struct lxc_conf *c, char *retv, int inlen, int v)
 {
 	int len;

src/lxc/confile_utils.h

@@ -72,6 +72,7 @@ extern bool lxc_config_net_hwaddr(const char *line);
 extern void update_hwaddr(const char *line);
 extern bool new_hwaddr(char *hwaddr);
 extern int lxc_get_conf_str(char *retv, int inlen, const char *value);
+extern int lxc_get_conf_bool(struct lxc_conf *c, char *retv, int inlen, bool v);
 extern int lxc_get_conf_int(struct lxc_conf *c, char *retv, int inlen, int v);
 extern int lxc_get_conf_size_t(struct lxc_conf *c, char *retv, int inlen, size_t v);
 extern int lxc_get_conf_uint64(struct lxc_conf *c, char *retv, int inlen, uint64_t v);

src/lxc/lxccontainer.c

@@ -2984,6 +2984,10 @@ static bool container_destroy(struct lxc_container *c,
 		}
 	}
 
+	/* LXC is not managing the storage of the container. */
+	if (conf && !conf->rootfs.managed)
+		goto on_success;
+
 	if (conf && conf->rootfs.path && conf->rootfs.mount) {
 		if (!do_destroy_container(conf)) {
 			ERROR("Error destroying rootfs for %s", c->name);
@@ -3056,6 +3060,7 @@ static bool container_destroy(struct lxc_container *c,
 	}
 	INFO("Destroyed directory \"%s\" for \"%s\"", path, c->name);
 
+on_success:
 	bret = true;
 
 out:
@@ -3071,14 +3076,16 @@ static bool do_lxcapi_destroy(struct lxc_container *c)
 	if (!c || !lxcapi_is_defined(c))
 		return false;
 
-	if (has_snapshots(c)) {
-		ERROR("Container %s has snapshots;  not removing", c->name);
-		return false;
-	}
+	if (c->lxc_conf && c->lxc_conf->rootfs.managed) {
+		if (has_snapshots(c)) {
+			ERROR("Container %s has snapshots;  not removing", c->name);
+			return false;
+		}
 
-	if (has_fs_snapshots(c)) {
-		ERROR("container %s has snapshots on its rootfs", c->name);
-		return false;
+		if (has_fs_snapshots(c)) {
+			ERROR("container %s has snapshots on its rootfs", c->name);
+			return false;
+		}
 	}
 
 	return container_destroy(c, NULL);