Create arrays via metadata-update

Support creating arrays inside an active ddf container by
sending a metadata update over a pipe to mdmon.

Create.c

@@ -573,12 +573,13 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 				return 1;
 			}
 			if (mdmon_running(st->container_dev)) {
-				fprintf(stderr, Name ": mdmon already running "
-					"for %s - sorry\n",
-					devnum2devname(st->container_dev));
-				return 1;
-			}
-			need_mdmon = 1;
+				if (verbose)
+					fprintf(stderr, Name ": reusing mdmon "
+						"for %s.\n",
+						devnum2devname(st->container_dev));
+				st->update_tail = &st->updates;
+			} else
+				need_mdmon = 1;
 		}
 		if ((vers % 100) < 2 ||
 		    sra == NULL ||
@@ -707,8 +708,10 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 			}
 			if (dv == moved_disk && dnum != insert_point) break;
 		}
-		if (pass == 1)
+		if (pass == 1) {
 			st->ss->write_init_super(st);
+			flush_metadata_updates(st);
+		}
 	}
 	free(infos);
 	st->ss->free_super(st);

managemon.c

@@ -428,9 +428,25 @@ void manage(struct mdstat_ent *mdstat, struct supertype *container)
 	}
 }
 
-static int handle_message(struct supertype *container, struct metadata_update *msg)
+static void handle_message(struct supertype *container, struct metadata_update *msg)
 {
-	return -1;
+	/* queue this metadata update through to the monitor */
+
+	struct metadata_update *mu;
+
+	if (msg->len == 0) {
+		wait_update_handled();
+	} else {
+		mu = malloc(sizeof(*mu));
+		mu->len = msg->len;
+		mu->buf = msg->buf;
+		msg->buf = NULL;
+		mu->space = NULL;
+		mu->next = NULL;
+		if (container->ss->prepare_update)
+			container->ss->prepare_update(container, mu);
+		queue_metadata_update(mu);
+	}
 }
 
 void read_sock(struct supertype *container)
@@ -460,8 +476,6 @@ void read_sock(struct supertype *container)
 		} else
 			terminate = 1;
 
-		if (msg.buf)
-			free(msg.buf);
 	} while (!terminate);
 
 	close(fd);

mdadm.h

@@ -542,6 +542,8 @@ extern struct superswitch {
 	void (*sync_metadata)(struct supertype *st);
 	void (*process_update)(struct supertype *st,
 			       struct metadata_update *update);
+	void (*prepare_update)(struct supertype *st,
+			       struct metadata_update *update);
 
 	/* activate_spare will check if the array is degraded and, if it
 	 * is, try to find some spare space in the container.
@@ -559,6 +561,13 @@ extern struct superswitch {
 
 extern struct superswitch super_imsm;
 
+struct metadata_update {
+	int	len;
+	char	*buf;
+	void	*space; /* allocated space that monitor will use */
+	struct metadata_update *next;
+};
+
 /* A supertype holds a particular collection of metadata.
  * It identifies the metadata type by the superswitch, and the particular
  * sub-version of that metadata type.
@@ -579,6 +588,9 @@ struct supertype {
 	void *sb;
 	void *info;
 
+	struct metadata_update *updates;
+	struct metadata_update **update_tail;
+
 	/* extra stuff used by mdmon */
 	struct active_array *arrays;
 	int sock; /* listen to external programs */
@@ -738,6 +750,8 @@ extern unsigned long long get_component_size(int fd);
 extern void remove_partitions(int fd);
 extern unsigned long long calc_array_size(int level, int raid_disks, int layout,
 				   int chunksize, unsigned long long devsize);
+extern int flush_metadata_updates(struct supertype *st);
+extern void append_metadata_update(struct supertype *st, void *buf, int len);
 
 
 extern char *human_size(long long bytes);

mdmon.h

@@ -41,12 +41,6 @@ struct active_array {
  * superswitch.  All common code sees them as opaque
  * blobs.
  */
-struct metadata_update {
-	int	len;
-	char	*buf;
-	void	*space; /* allocated space that monitor will use */
-	struct metadata_update *next;
-};
 extern struct metadata_update *update_queue, *update_queue_handled;
 
 #define MD_MAJOR 9

super-ddf.c

@@ -2122,7 +2122,32 @@ static int __write_init_super_ddf(struct supertype *st, int do_close)
 
 static int write_init_super_ddf(struct supertype *st)
 {
-	return __write_init_super_ddf(st, 1);
+
+	if (st->update_tail) {
+		/* queue the virtual_disk and vd_config as metadata updates */
+		struct virtual_disk *vd;
+		struct vd_config *vc;
+		struct ddf_super *ddf = st->sb;
+		int len;
+
+		/* First the virtual disk.  We have a slightly fake header */
+		len = sizeof(struct virtual_disk) + sizeof(struct virtual_entry);
+		vd = malloc(len);
+		*vd = *ddf->virt;
+		vd->entries[0] = ddf->virt->entries[ddf->currentconf->vcnum];
+		vd->populated_vdes = __cpu_to_be16(ddf->currentconf->vcnum);
+		append_metadata_update(st, vd, len);
+
+		/* Then the vd_config */
+		len = ddf->conf_rec_len * 512;
+		vc = malloc(len);
+		memcpy(vc, &ddf->currentconf->conf, len);
+		append_metadata_update(st, vc, len);
+
+		/* FIXME I need to close the fds! */
+		return 0;
+	} else 
+		return __write_init_super_ddf(st, 1);
 }
 
 #endif
@@ -2812,7 +2837,7 @@ static void ddf_process_update(struct supertype *st,
 		printf("len %d %d\n", update->len, ddf->conf_rec_len);
 
 		mppe = __be16_to_cpu(ddf->anchor.max_primary_element_entries);
-		if (update->len != ddf->conf_rec_len)
+		if (update->len != ddf->conf_rec_len * 512)
 			return;
 		vc = (struct vd_config*)update->buf;
 		for (vcl = ddf->conflist; vcl ; vcl = vcl->next)
@@ -2830,7 +2855,7 @@ static void ddf_process_update(struct supertype *st,
 			vcl = update->space;
 			update->space = NULL;
 			vcl->next = ddf->conflist;
-			vcl->conf = *vc;
+			memcpy(&vcl->conf, vc, update->len);
 			vcl->lba_offset = (__u64*)
 				&vcl->conf.phys_refnum[mppe];
 			ddf->conflist = vcl;
@@ -2876,6 +2901,20 @@ static void ddf_process_update(struct supertype *st,
 	}
 }
 
+static void ddf_prepare_update(struct supertype *st,
+			       struct metadata_update *update)
+{
+	/* This update arrived at managemon.
+	 * We are about to pass it to monitor.
+	 * If a malloc is needed, do it here.
+	 */
+	struct ddf_super *ddf = st->sb;
+	__u32 *magic = (__u32*)update->buf;
+	if (*magic == DDF_VD_CONF_MAGIC)
+		update->space = malloc(offsetof(struct vcl, conf)
+				       + ddf->conf_rec_len * 512);
+}
+
 /*
  * Check if the array 'a' is degraded but not failed.
  * If it is, find as many spares as are available and needed and
@@ -3106,6 +3145,7 @@ struct superswitch super_ddf = {
 	.set_disk       = ddf_set_disk,
 	.sync_metadata  = ddf_sync_metadata,
 	.process_update	= ddf_process_update,
+	.prepare_update	= ddf_prepare_update,
 	.activate_spare = ddf_activate_spare,
 
 };

util.c

@@ -29,7 +29,9 @@
 
 #include	"mdadm.h"
 #include	"md_p.h"
+#include	<sys/socket.h>
 #include	<sys/utsname.h>
+#include	<sys/un.h>
 #include	<ctype.h>
 #include	<dirent.h>
 #include	<signal.h>
@@ -1065,6 +1067,47 @@ int signal_mdmon(int devnum)
 }
 
 
+int flush_metadata_updates(struct supertype *st)
+{
+	int sfd;
+	if (!st->updates) {
+		st->update_tail = NULL;
+		return -1;
+	}
+
+	sfd = connect_monitor(devnum2devname(st->container_dev));
+	if (sfd < 0)
+		return -1;
+
+	while (st->updates) {
+		struct metadata_update *mu = st->updates;
+		st->updates = mu->next;
+
+		send_message(sfd, mu, 0);
+		wait_reply(sfd, 0);
+		free(mu->buf);
+		free(mu);
+	}
+	ack(sfd, 0);
+	wait_reply(sfd, 0);
+	close(sfd);
+	st->update_tail = NULL;
+	return 0;
+}
+
+void append_metadata_update(struct supertype *st, void *buf, int len)
+{
+
+	struct metadata_update *mu = malloc(sizeof(*mu));
+
+	mu->buf = buf;
+	mu->len = len;
+	mu->space = NULL;
+	mu->next = NULL;
+	*st->update_tail = mu;
+	st->update_tail = &mu->next;
+}
+
 
 #ifdef __TINYC__
 /* tinyc doesn't optimize this check in ioctl.h out ... */