Add `gmirror create` subcommand, alike to gstripe, gconcat, etc.

It is quite specific mode of operation without storing on-disk metadata.
It can be useful in some cases in combination with some external control
tools handling mirror creation and disks hot-plug.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.

3 files changed, 244 insertions, 14 deletions

diff --git a/sys/geom/mirror/g_mirror.c b/sys/geom/mirror/g_mirror.c
index e1daae1ddaf1..02ca68b9cee8 100644
--- a/sys/geom/mirror/g_mirror.c
+++ b/sys/geom/mirror/g_mirror.c
@@ -700,6 +700,8 @@ g_mirror_clear_metadata(struct g_mirror_disk *disk)
 	g_topology_assert_not();
 	sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
 
+	if (disk->d_softc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
+		return (0);
 	error = g_mirror_write_metadata(disk, NULL);
 	if (error == 0) {
 		G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
@@ -765,6 +767,8 @@ g_mirror_update_metadata(struct g_mirror_disk *disk)
 	sc = disk->d_softc;
 	sx_assert(&sc->sc_lock, SX_LOCKED);
 
+	if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
+		return;
 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0)
 		g_mirror_fill_metadata(sc, disk, &md);
 	error = g_mirror_write_metadata(disk, &md);
@@ -2942,8 +2946,9 @@ end:
 	return (error);
 }
 
-static struct g_geom *
-g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
+struct g_geom *
+g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md,
+    u_int type)
 {
 	struct g_mirror_softc *sc;
 	struct g_geom *gp;
@@ -2966,6 +2971,7 @@ g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
 	gp->access = g_mirror_access;
 	gp->dumpconf = g_mirror_dumpconf;
 
+	sc->sc_type = type;
 	sc->sc_id = md->md_mid;
 	sc->sc_slice = md->md_slice;
 	sc->sc_balance = md->md_balance;
@@ -3142,6 +3148,8 @@ g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 		sc = gp->softc;
 		if (sc == NULL)
 			continue;
+		if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
+			continue;
 		if (sc->sc_sync.ds_geom == gp)
 			continue;
 		if (strcmp(md.md_name, sc->sc_name) != 0)
@@ -3154,7 +3162,7 @@ g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 		break;
 	}
 	if (gp == NULL) {
-		gp = g_mirror_create(mp, &md);
+		gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_AUTOMATIC);
 		if (gp == NULL) {
 			G_MIRROR_DEBUG(0, "Cannot create device %s.",
 			    md.md_name);
@@ -3302,6 +3310,19 @@ g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
 	} else {
 		g_topology_unlock();
 		sx_xlock(&sc->sc_lock);
+		sbuf_printf(sb, "%s<Type>", indent);
+		switch (sc->sc_type) {
+		case G_MIRROR_TYPE_AUTOMATIC:
+			sbuf_printf(sb, "AUTOMATIC");
+			break;
+		case G_MIRROR_TYPE_MANUAL:
+			sbuf_printf(sb, "MANUAL");
+			break;
+		default:
+			sbuf_printf(sb, "UNKNOWN");
+			break;
+		}
+		sbuf_printf(sb, "</Type>\n");
 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
 		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
 		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
diff --git a/sys/geom/mirror/g_mirror.h b/sys/geom/mirror/g_mirror.h
index ed499a55c8f3..bb49303ef3cc 100644
--- a/sys/geom/mirror/g_mirror.h
+++ b/sys/geom/mirror/g_mirror.h
@@ -165,11 +165,15 @@ struct g_mirror_event {
 #define	G_MIRROR_DEVICE_STATE_STARTING		0
 #define	G_MIRROR_DEVICE_STATE_RUNNING		1
 
+#define	G_MIRROR_TYPE_MANUAL	0
+#define	G_MIRROR_TYPE_AUTOMATIC	1
+
 /* Bump syncid on first write. */
 #define	G_MIRROR_BUMP_SYNCID	0x1
 /* Bump genid immediately. */
 #define	G_MIRROR_BUMP_GENID	0x2
 struct g_mirror_softc {
+	u_int		sc_type;	/* Device type (manual/automatic). */
 	u_int		sc_state;	/* Device state. */
 	uint32_t	sc_slice;	/* Slice size. */
 	uint8_t		sc_balance;	/* Balance algorithm. */
@@ -220,7 +224,11 @@ struct g_mirror_softc {
 };
 #define	sc_name	sc_geom->name
 
+struct g_mirror_metadata;
+
 u_int g_mirror_ndisks(struct g_mirror_softc *sc, int state);
+struct g_geom * g_mirror_create(struct g_class *mp,
+    const struct g_mirror_metadata *md, u_int type);
 #define	G_MIRROR_DESTROY_SOFT		0
 #define	G_MIRROR_DESTROY_DELAYED	1
 #define	G_MIRROR_DESTROY_HARD		2
diff --git a/sys/geom/mirror/g_mirror_ctl.c b/sys/geom/mirror/g_mirror_ctl.c
index df24e52aafaf..099e5d1bc7ce 100644
--- a/sys/geom/mirror/g_mirror_ctl.c
+++ b/sys/geom/mirror/g_mirror_ctl.c
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/bio.h>
+#include <sys/sbuf.h>
 #include <sys/sysctl.h>
 #include <sys/malloc.h>
 #include <sys/bitstring.h>
@@ -301,6 +302,182 @@ g_mirror_ctl_configure(struct gctl_req *req, struct g_class *mp)
 }
 
 static void
+g_mirror_create_orphan(struct g_consumer *cp)
+{
+
+	KASSERT(1 == 0, ("%s called while creating %s.", __func__,
+	    cp->provider->name));
+}
+
+static void
+g_mirror_ctl_create(struct gctl_req *req, struct g_class *mp)
+{
+	struct g_mirror_metadata md;
+	struct g_geom *gp;
+	struct g_consumer *cp;
+	struct g_provider *pp;
+	struct g_mirror_softc *sc;
+	struct sbuf *sb;
+	const char *name;
+	char param[16];
+	int *nargs;
+	intmax_t *val;
+	int *ival;
+	const char *sval;
+	int bal;
+	unsigned attached, no, sectorsize;
+	off_t mediasize;
+
+	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
+	if (nargs == NULL) {
+		gctl_error(req, "No '%s' argument.", "nargs");
+		return;
+	}
+	if (*nargs <= 2) {
+		gctl_error(req, "Too few arguments.");
+		return;
+	}
+
+	strlcpy(md.md_magic, G_MIRROR_MAGIC, sizeof(md.md_magic));
+	md.md_version = G_MIRROR_VERSION;
+	name = gctl_get_asciiparam(req, "arg0");
+	if (name == NULL) {
+		gctl_error(req, "No 'arg%u' argument.", 0);
+		return;
+	}
+	strlcpy(md.md_name, name, sizeof(md.md_name));
+	md.md_mid = arc4random();
+	md.md_all = *nargs - 1;
+	md.md_genid = 0;
+	md.md_syncid = 1;
+	md.md_sync_offset = 0;
+	val = gctl_get_paraml(req, "slice", sizeof(*val));
+	if (val == NULL) {
+		gctl_error(req, "No slice argument.");
+		return;
+	}
+	md.md_slice = *val;
+	sval = gctl_get_asciiparam(req, "balance");
+	if (sval == NULL) {
+		gctl_error(req, "No balance argument.");
+		return;
+	}
+	bal = balance_id(sval);
+	if (bal < 0) {
+		gctl_error(req, "Invalid balance algorithm.");
+		return;
+	}
+	md.md_balance = bal;
+	md.md_mflags = 0;
+	md.md_dflags = 0;
+	ival = gctl_get_paraml(req, "noautosync", sizeof(*ival));
+	if (ival != NULL && *ival)
+		md.md_mflags |= G_MIRROR_DEVICE_FLAG_NOAUTOSYNC;
+	ival = gctl_get_paraml(req, "nofailsync", sizeof(*ival));
+	if (ival != NULL && *ival)
+		md.md_mflags |= G_MIRROR_DEVICE_FLAG_NOFAILSYNC;
+	/* These fields not used in manual mode. */
+	bzero(md.md_provider, sizeof(md.md_provider));
+	md.md_provsize = 0;
+
+	g_topology_lock();
+	mediasize = OFF_MAX;
+	sectorsize = 0;
+	gp = g_new_geomf(mp, "%s", md.md_name);
+	gp->orphan = g_mirror_create_orphan;
+	cp = g_new_consumer(gp);
+	for (no = 1; no < *nargs; no++) {
+		snprintf(param, sizeof(param), "arg%u", no);
+		name = gctl_get_asciiparam(req, param);
+		if (name == NULL) {
+			gctl_error(req, "No 'arg%u' argument.", no);
+err:
+			g_destroy_consumer(cp);
+			g_destroy_geom(gp);
+			g_topology_unlock();
+			return;
+		}
+		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
+			name += strlen("/dev/");
+		pp = g_provider_by_name(name);
+		if (pp == NULL) {
+			G_MIRROR_DEBUG(1, "Disk %s is invalid.", name);
+			gctl_error(req, "Disk %s is invalid.", name);
+			goto err;
+		}
+		g_attach(cp, pp);
+		if (g_access(cp, 1, 0, 0) != 0) {
+			G_MIRROR_DEBUG(1, "Can't open disk %s.", name);
+			gctl_error(req, "Can't open disk %s.", name);
+err2:
+			g_detach(cp);
+			goto err;
+		}
+		if (pp->mediasize == 0 || pp->sectorsize == 0) {
+			G_MIRROR_DEBUG(1, "Disk %s has no media.", name);
+			gctl_error(req, "Disk %s has no media.", name);
+			g_access(cp, -1, 0, 0);
+			goto err2;
+		}
+		if (pp->mediasize < mediasize)
+			mediasize = pp->mediasize;
+		if (pp->sectorsize > sectorsize)
+			sectorsize = pp->sectorsize;
+		g_access(cp, -1, 0, 0);
+		g_detach(cp);
+	}
+	g_destroy_consumer(cp);
+	g_destroy_geom(gp);
+	md.md_mediasize = mediasize;
+	md.md_sectorsize = sectorsize;
+	md.md_mediasize -= (md.md_mediasize % md.md_sectorsize);
+
+	gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_MANUAL);
+	if (gp == NULL) {
+		gctl_error(req, "Can't create %s.", md.md_name);
+		g_topology_unlock();
+		return;
+	}
+
+	sc = gp->softc;
+	g_topology_unlock();
+	sx_xlock(&sc->sc_lock);
+	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
+	sb = sbuf_new_auto();
+	sbuf_printf(sb, "Can't attach disk(s) to %s:", gp->name);
+	for (attached = 0, no = 1; no < *nargs; no++) {
+		snprintf(param, sizeof(param), "arg%u", no);
+		name = gctl_get_asciiparam(req, param);
+		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
+			name += strlen("/dev/");
+		pp = g_provider_by_name(name);
+		if (pp == NULL) {
+			G_MIRROR_DEBUG(1, "Provider %s disappear?!", name);
+			sbuf_printf(sb, " %s", name);
+			continue;
+		}
+		md.md_did = arc4random();
+		md.md_priority = no - 1;
+		if (g_mirror_add_disk(sc, pp, &md) != 0) {
+			G_MIRROR_DEBUG(1, "Disk %u (%s) not attached to %s.",
+			    no, pp->name, gp->name);
+			sbuf_printf(sb, " %s", pp->name);
+			continue;
+		}
+		attached++;
+	}
+	sbuf_finish(sb);
+	sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
+	if (md.md_all != attached ||
+	    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
+		g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_HARD);
+		gctl_error(req, "%s", sbuf_data(sb));
+	} else
+		sx_xunlock(&sc->sc_lock);
+	sbuf_delete(sb);
+}
+
+static void
 g_mirror_ctl_rebuild(struct gctl_req *req, struct g_class *mp)
 {
 	struct g_mirror_metadata md;
@@ -401,6 +578,7 @@ g_mirror_ctl_insert(struct gctl_req *req, struct g_class *mp)
 		struct g_provider	*provider;
 		struct g_consumer	*consumer;
 	} *disks;
+	off_t mdsize;
 
 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
 	if (nargs == NULL) {
@@ -462,16 +640,6 @@ g_mirror_ctl_insert(struct gctl_req *req, struct g_class *mp)
 			gctl_error(req, "Unknown provider %s.", name);
 			continue;
 		}
-		if (sc->sc_provider->mediasize >
-		    pp->mediasize - pp->sectorsize) {
-			gctl_error(req, "Provider %s too small.", name);
-			continue;
-		}
-		if ((sc->sc_provider->sectorsize % pp->sectorsize) != 0) {
-			gctl_error(req, "Invalid sectorsize of provider %s.",
-			    name);
-			continue;
-		}
 		cp = g_new_consumer(sc->sc_geom);
 		if (g_attach(cp, pp) != 0) {
 			g_destroy_consumer(cp);
@@ -479,9 +647,40 @@ g_mirror_ctl_insert(struct gctl_req *req, struct g_class *mp)
 			continue;
 		}
 		if (g_access(cp, 0, 1, 1) != 0) {
+			gctl_error(req, "Cannot access provider %s.", name);
+err:
 			g_detach(cp);
 			g_destroy_consumer(cp);
-			gctl_error(req, "Cannot access provider %s.", name);
+			continue;
+		}
+		mdsize = (sc->sc_type == G_MIRROR_TYPE_AUTOMATIC) ?
+		    pp->sectorsize : 0;
+		if (sc->sc_provider->mediasize > pp->mediasize - mdsize) {
+			gctl_error(req, "Provider %s too small.", name);
+err2:
+			g_access(cp, 0, -1, -1);
+			goto err;
+		}
+		if ((sc->sc_provider->sectorsize % pp->sectorsize) != 0) {
+			gctl_error(req, "Invalid sectorsize of provider %s.",
+			    name);
+			goto err2;
+		}
+		if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC) {
+			g_access(cp, 0, -1, -1);
+			g_detach(cp);
+			g_destroy_consumer(cp);
+			g_topology_unlock();
+			sc->sc_ndisks++;
+			g_mirror_fill_metadata(sc, NULL, &md);
+			md.md_priority = *priority;
+			if (*inactive)
+				md.md_dflags |= G_MIRROR_DISK_FLAG_INACTIVE;
+			if (g_mirror_add_disk(sc, pp, &md) != 0) {
+				sc->sc_ndisks--;
+				gctl_error(req, "Disk %s not inserted.", name);
+			}
+			g_topology_lock();
 			continue;
 		}
 		disks[n].provider = pp;
@@ -872,6 +1071,8 @@ g_mirror_config(struct gctl_req *req, struct g_class *mp, const char *verb)
 	g_topology_unlock();
 	if (strcmp(verb, "configure") == 0)
 		g_mirror_ctl_configure(req, mp);
+	else if (strcmp(verb, "create") == 0)
+		g_mirror_ctl_create(req, mp);
 	else if (strcmp(verb, "rebuild") == 0)
 		g_mirror_ctl_rebuild(req, mp);
 	else if (strcmp(verb, "insert") == 0)