Add DEFINE_ARRAY_FREE_FUNC and mount_image_free_array

This is similar to DEFINE_POINTER_ARRAY_FREE_FUNC, but one
pointer chase less. The name of the outer and inner functions are
specified separately. The inner function does not free, so it'll
be generally something like 'foo_done', but the outer function
does free, so it can be called 'foo_array_free'.

src/core/dbus-execute.c

@@ -4055,7 +4055,7 @@ int bus_exec_context_set_transient_property(
                 MountImage *mount_images = NULL;
                 size_t n_mount_images = 0;
 
-                CLEANUP_ARRAY(mount_images, n_mount_images, mount_image_free_many);
+                CLEANUP_ARRAY(mount_images, n_mount_images, mount_image_free_array);
 
                 r = sd_bus_message_enter_container(message, 'a', "(ssba(ss))");
                 if (r < 0)
@@ -4127,7 +4127,7 @@ int bus_exec_context_set_transient_property(
 
                 if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
                         if (n_mount_images == 0) {
-                                mount_image_free_many(c->mount_images, c->n_mount_images);
+                                mount_image_free_array(c->mount_images, c->n_mount_images);
                                 c->mount_images = NULL;
                                 c->n_mount_images = 0;
 
@@ -4158,7 +4158,7 @@ int bus_exec_context_set_transient_property(
                 MountImage *extension_images = NULL;
                 size_t n_extension_images = 0;
 
-                CLEANUP_ARRAY(extension_images, n_extension_images, mount_image_free_many);
+                CLEANUP_ARRAY(extension_images, n_extension_images, mount_image_free_array);
 
                 r = sd_bus_message_enter_container(message, 'a', "(sba(ss))");
                 if (r < 0)
@@ -4220,7 +4220,7 @@ int bus_exec_context_set_transient_property(
 
                 if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
                         if (n_extension_images == 0) {
-                                mount_image_free_many(c->extension_images, c->n_extension_images);
+                                mount_image_free_array(c->extension_images, c->n_extension_images);
                                 c->extension_images = NULL;
                                 c->n_extension_images = 0;
 

src/core/execute.c

@@ -696,10 +696,10 @@ void exec_context_done(ExecContext *c) {
         bind_mount_free_many(c->bind_mounts, c->n_bind_mounts);
         c->bind_mounts = NULL;
         c->n_bind_mounts = 0;
-        mount_image_free_many(c->mount_images, c->n_mount_images);
+        mount_image_free_array(c->mount_images, c->n_mount_images);
         c->mount_images = NULL;
         c->n_mount_images = 0;
-        mount_image_free_many(c->extension_images, c->n_extension_images);
+        mount_image_free_array(c->extension_images, c->n_extension_images);
         c->extension_images = NULL;
         c->n_extension_images = 0;
         c->extension_directories = strv_free(c->extension_directories);

src/core/load-fragment.c

@@ -5235,7 +5235,7 @@ int config_parse_mount_images(
 
         if (isempty(rvalue)) {
                 /* Empty assignment resets the list */
-                mount_image_free_many(c->mount_images, c->n_mount_images);
+                mount_image_free_array(c->mount_images, c->n_mount_images);
                 c->mount_images = NULL;
                 c->n_mount_images = 0;
                 return 0;
@@ -5385,7 +5385,7 @@ int config_parse_extension_images(
 
         if (isempty(rvalue)) {
                 /* Empty assignment resets the list */
-                mount_image_free_many(c->extension_images, c->n_extension_images);
+                mount_image_free_array(c->extension_images, c->n_extension_images);
                 c->extension_images = NULL;
                 c->n_extension_images = 0;
                 return 0;

src/core/namespace.c

@@ -3250,18 +3250,15 @@ int bind_mount_add(BindMount **b, size_t *n, const BindMount *item) {
         return 0;
 }
 
-void mount_image_free_many(MountImage *m, size_t n) {
-        assert(m || n == 0);
-
-        FOREACH_ARRAY(i, m, n) {
-                free(i->source);
-                free(i->destination);
-                mount_options_free_all(i->mount_options);
-        }
-
-        free(m);
+static void mount_image_done(MountImage *m) {
+        assert(m);
+        m->source = mfree(m->source);
+        m->destination = mfree(m->destination);
+        m->mount_options = mount_options_free_all(m->mount_options);
 }
 
+DEFINE_ARRAY_FREE_FUNC(mount_image_free_array, MountImage, mount_image_done);
+
 int mount_image_add(MountImage **m, size_t *n, const MountImage *item) {
         _cleanup_free_ char *s = NULL, *d = NULL;
         _cleanup_(mount_options_free_allp) MountOptions *o = NULL;

src/core/namespace.h

@@ -303,7 +303,7 @@ DECLARE_STRING_TABLE_LOOKUP(private_pids, PrivatePIDs);
 void bind_mount_free_many(BindMount *b, size_t n);
 int bind_mount_add(BindMount **b, size_t *n, const BindMount *item);
 
-void mount_image_free_many(MountImage *m, size_t n);
+void mount_image_free_array(MountImage *array, size_t n);
 int mount_image_add(MountImage **m, size_t *n, const MountImage *item);
 
 void temporary_filesystem_free_many(TemporaryFileSystem *t, size_t n);

src/fundamental/cleanup-fundamental.h

@@ -64,6 +64,16 @@
                 free(array);                                    \
         }
 
+/* Clean up an array of objects of known size by dropping all the items in it.
+ * Then free the array itself. */
+#define DEFINE_ARRAY_FREE_FUNC(name, type, helper)              \
+        void name(type *array, size_t n) {                      \
+                assert(array || n == 0);                        \
+                FOREACH_ARRAY(item, array, n)                   \
+                        helper(item);                           \
+                free(array);                                    \
+        }
+
 typedef void (*free_array_func_t)(void *p, size_t n);
 
 /* An automatic _cleanup_-like logic for destroy arrays (i.e. pointers + size) when leaving scope */