Allow a metadata update to have a linked list of allocated spaces.

Sometimes one metadata update will require allocating several
larger data structures.  As 'monitor' cannot allocate, 'manager'
must, so it must be able to attach a list of allocates to the
update, and importantly it must be able to easily free them.

So add a 'space_list' element to metadata updates where each
element on the list starts with a pointer to the next.

Signed-off-by: NeilBrown <neilb@suse.de>

managemon.c

@@ -217,10 +217,16 @@ static void free_updates(struct metadata_update **update)
 {
 	while (*update) {
 		struct metadata_update *this = *update;
+		void **space_list = this->space_list;
 
 		*update = this->next;
 		free(this->buf);
 		free(this->space);
+		while (space_list) {
+			void *space = space_list;
+			space_list = *space_list;
+			free(space);
+		}
 		free(this);
 	}
 }
@@ -710,6 +716,7 @@ static void handle_message(struct supertype *container, struct metadata_update *
 		mu->buf = msg->buf;
 		msg->buf = NULL;
 		mu->space = NULL;
+		mu->space_list = NULL;
 		mu->next = NULL;
 		if (container->ss->prepare_update)
 			container->ss->prepare_update(container, mu);

mdadm.h

@@ -764,6 +764,9 @@ struct metadata_update {
 	int	len;
 	char	*buf;
 	void	*space; /* allocated space that monitor will use */
+	void	**space_list; /* list of allocated spaces that monitor can
+			       * use or that it returned.
+			       */
 	struct metadata_update *next;
 };
 

super-intel.c

@@ -5357,6 +5357,7 @@ static struct mdinfo *imsm_activate_spare(struct active_array *a,
 	}
 			
 	mu->space = NULL;
+	mu->space_list = NULL;
 	mu->len = sizeof(struct imsm_update_activate_spare) * num_spares;
 	mu->next = *updates;
 	u = (struct imsm_update_activate_spare *) mu->buf;

util.c

@@ -1890,6 +1890,7 @@ void append_metadata_update(struct supertype *st, void *buf, int len)
 	mu->buf = buf;
 	mu->len = len;
 	mu->space = NULL;
+	mu->space_list = NULL;
 	mu->next = NULL;
 	*st->update_tail = mu;
 	st->update_tail = &mu->next;