- Implement the grow command to make it easier for users to extend plexes

without having to understand all gvinum internals.
- Document the grow command in the manpage and update examples to use the
  command where possible.

sbin/gvinum/gvinum.8

@@ -79,6 +79,10 @@ flag is given.
 .It Ic detach Oo Fl f Oc Op Ar plex | subdisk
 Detach a plex or subdisk from the volume or plex to which it is
 attached.
+.It Ic grow Ar plex device
+Grow a plex by creating a gvinum drive and subdisk on device and attach it to
+the plex.
+If required by the plex organization, it will be put into the growable state.
 .It Ic help
 Provides a synopsis of
 .Nm
@@ -333,16 +337,11 @@ Then, initiate the rebuild:
 The plex will go up form degraded mode after the rebuild is finished.
 The plex can still be used while the rebuild is in progress, although requests
 might be delayed.
-For a more advanced usage and detailed explanation of gvinum, the
-handbook is recommended.
 .Pp
 Given the configuration as in the previous example, growing a RAID-5 or STRIPED
-array is accomplished by adding a new subdisk to the plex with a
-.Ar description-file
-similar to this:
+array is accomplished by using the grow command:
 .Pp
-.Dl "drive newdrive device /dev/ad4"
-.Dl "sd drive newdrive plex myraid5vol.p0"
+.Dl "gvinum grow myraid5vol.p0 /dev/ad4"
 .Pp
 If everything went ok, the plex state should now be set to growable.
 You can then start the growing with the
@@ -355,6 +354,9 @@ As with rebuilding, you can watch the progress using the
 .Ic list
 command.
 .Pp
+For a more advanced usage and detailed explanation of gvinum, the
+handbook is recommended.
+.Pp
 .Sh SEE ALSO
 .Xr geom 4 ,
 .Xr geom 8

sbin/gvinum/gvinum.c

@@ -61,6 +61,7 @@ void	gvinum_attach(int, char **);
 void	gvinum_concat(int, char **);
 void	gvinum_create(int, char **);
 void	gvinum_detach(int, char **);
+void	gvinum_grow(int, char **);
 void	gvinum_help(void);
 void	gvinum_list(int, char **);
 void	gvinum_move(int, char **);
@@ -690,6 +691,8 @@ gvinum_help(void)
 	    "detach [-f] [plex | subdisk]\n"
 	    "        Detach a plex or a subdisk from the volume or plex to\n"
 	    "        which it is attached.\n"
+	    "grow plex drive\n"
+	    "        Grow plex by creating a properly sized subdisk on drive\n"
 	    "l | list [-r] [-v] [-V] [volume | plex | subdisk]\n"
 	    "        List information about specified objects.\n"
 	    "ld [-r] [-v] [-V] [volume]\n"
@@ -1242,6 +1245,87 @@ gvinum_stripe(int argc, char **argv)
 	create_volume(argc, argv, "stripe");
 }
 
+/* Grow a subdisk by adding disk backed by provider. */
+void
+gvinum_grow(int argc, char **argv)
+{
+	struct gctl_req *req;
+	char *drive, *sdname;
+	char sdprefix[GV_MAXSDNAME];
+	struct gv_drive *d;
+	struct gv_sd *s;
+	const char *errstr;
+	int drives, volumes, plexes, subdisks, flags;
+
+	drives = volumes = plexes = subdisks = 0;
+	if (argc < 3) {
+		warnx("usage:\tgrow plex drive\n");
+		return;
+	}
+
+	s = gv_alloc_sd();
+	if (s == NULL) {
+		warn("unable to create subdisk");
+		return;
+	}
+	d = gv_alloc_drive();
+	if (d == NULL) {
+		warn("unable to create drive");
+		free(s);
+		return;
+	}
+	/* Lookup device and set an appropriate drive name. */
+	drive = find_drive(argv[2]);
+	if (drive == NULL) {
+		warn("unable to find an appropriate drive name");
+		free(s);
+		free(d);
+		return;
+	}
+	strlcpy(d->name, drive, sizeof(d->name));
+	if (strncmp(argv[2], "/dev/", 5) == 0)
+		strlcpy(d->device, (argv[2] + 5), sizeof(d->device));
+	else
+		strlcpy(d->device, argv[2], sizeof(d->device));
+	drives = 1;
+
+	/* We try to use the plex name as basis for the subdisk name. */
+	snprintf(sdprefix, sizeof(sdprefix), "%s.s", argv[1]);
+	sdname = find_name(sdprefix, GV_TYPE_SD, GV_MAXSDNAME);
+	if (sdname == NULL) {
+		warn("unable to find an appropriate subdisk name");
+		free(s);
+		free(d);
+		free(drive);
+		return;
+	}
+	strlcpy(s->name, sdname, sizeof(s->name));
+	free(sdname);
+	strlcpy(s->plex, argv[1], sizeof(s->plex));
+	strlcpy(s->drive, d->name, sizeof(s->drive));
+	subdisks = 1;
+
+	req = gctl_get_handle();
+	gctl_ro_param(req, "class", -1, "VINUM");
+	gctl_ro_param(req, "verb", -1, "create");
+	gctl_ro_param(req, "flags", sizeof(int), &flags);
+	gctl_ro_param(req, "volumes", sizeof(int), &volumes);
+	gctl_ro_param(req, "plexes", sizeof(int), &plexes);
+	gctl_ro_param(req, "subdisks", sizeof(int), &subdisks);
+	gctl_ro_param(req, "drives", sizeof(int), &drives);
+	gctl_ro_param(req, "drive0", sizeof(*d), d);
+	gctl_ro_param(req, "sd0", sizeof(*s), s);
+	errstr = gctl_issue(req);
+	free(drive);
+	if (errstr != NULL) {
+		warnx("unable to grow plex: %s", errstr);
+		free(s);
+		free(d);
+		return;
+	}
+	gctl_free(req);
+}
+
 void
 parseline(int argc, char **argv)
 {
@@ -1258,6 +1342,8 @@ parseline(int argc, char **argv)
 		gvinum_detach(argc, argv);
 	else if (!strcmp(argv[0], "concat"))
 		gvinum_concat(argc, argv);
+	else if (!strcmp(argv[0], "grow"))
+		gvinum_grow(argc, argv);
 	else if (!strcmp(argv[0], "help"))
 		gvinum_help();
 	else if (!strcmp(argv[0], "list") || !strcmp(argv[0], "l"))