lxccontainer: switch api to new clearer callbacks

src/lxc/confile.c

@@ -1040,7 +1040,7 @@ static int set_config_network_ipv4(const char *key, const char *value,
 	char *addr = NULL, *bcast = NULL, *prefix = NULL;
 
 	if (config_value_empty(value))
-		return lxc_clear_config_item(lxc_conf, key);
+		return clr_config_network_item(key, lxc_conf);
 
 	netdev = network_netdev(key, value, &lxc_conf->network);
 	if (!netdev)
@@ -1169,7 +1169,7 @@ static int set_config_network_ipv6(const char *key, const char *value,
 	char *slash, *valdup, *netmask;
 
 	if (config_value_empty(value))
-		return lxc_clear_config_item(lxc_conf, key);
+		return clr_config_network_item(key, lxc_conf);
 
 	netdev = network_netdev(key, value, &lxc_conf->network);
 	if (!netdev)
@@ -2128,7 +2128,7 @@ static int set_config_fstab(const char *key, const char *value,
 			    struct lxc_conf *lxc_conf)
 {
 	if (config_value_empty(value)) {
-		lxc_clear_config_item(lxc_conf, key);
+		clr_config_fstab(key, lxc_conf);
 		return -1;
 	}
 
@@ -2452,7 +2452,7 @@ static int set_config_includefiles(const char *key, const char *value,
 {
 	/* Set config value to default. */
 	if (config_value_empty(value)) {
-		lxc_clear_config_item(lxc_conf, key);
+		clr_config_includefiles(key, lxc_conf);
 		return 0;
 	}
 
@@ -2511,7 +2511,7 @@ static int set_config_utsname(const char *key, const char *value,
 	struct utsname *utsname;
 
 	if (config_value_empty(value)) {
-		lxc_clear_config_item(lxc_conf, key);
+		clr_config_utsname(key, lxc_conf);
 		return 0;
 	}
 
@@ -2771,11 +2771,6 @@ static inline int lxc_get_conf_int(struct lxc_conf *c, char *retv, int inlen,
 	return snprintf(retv, inlen, "%d", v);
 }
 
-int lxc_clear_config_item(struct lxc_conf *c, const char *key)
-{
-	return 0;
-}
-
 /* Write out a configuration file. */
 void write_config(FILE *fout, struct lxc_conf *c)
 {

src/lxc/confile.h

@@ -38,7 +38,7 @@ struct lxc_config_t {
 	char *name;
 	config_set_cb set;
 	config_get_cb get;
-	config_clr_cb clear;
+	config_clr_cb clr;
 };
 
 extern struct lxc_config_t *lxc_getconfig(const char *key);

src/lxc/lxccontainer.c

@@ -1676,17 +1676,27 @@ static void do_clear_unexp_config_line(struct lxc_conf *conf, const char *key)
 		WARN("Error clearing configuration for %s", key);
 }
 
-static bool do_lxcapi_clear_config_item(struct lxc_container *c, const char *key)
+static bool do_lxcapi_clear_config_item(struct lxc_container *c,
+					const char *key)
 {
-	int ret;
+	int ret = 1;
+	struct lxc_config_t *config;
 
 	if (!c || !c->lxc_conf)
 		return false;
+
 	if (container_mem_lock(c))
 		return false;
-	ret = lxc_clear_config_item(c->lxc_conf, key);
+
+	config = lxc_getconfig(key);
+	/* Verify that the config key exists and that it has a callback
+	 * implemented.
+	 */
+	if (config && config->clr)
+		ret = config->clr(key, c->lxc_conf);
 	if (!ret)
 		do_clear_unexp_config_line(c->lxc_conf, key);
+
 	container_mem_unlock(c);
 	return ret == 0;
 }