Rename subarray v2

Allow the name of the array stored in the metadata to be updated.  In
some cases the metadata format may not be able to support this rename
without modifying the UUID.  In these cases the request will be blocked.
Otherwise we allow the rename to take place, even for active arrays.
This assumes that the user understands the difference between the kernel
node name, the device node symlink name, and the metadata specific name.

Anticipating further need to modify subarrays in-place, introduce the
->update_subarray() superswitch method.  A future potential use
case is setting storage pool (spare-group) identifiers.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 107 insertions, 10 deletions

diff --git a/super-intel.c b/super-intel.c
index d81d620..f0377b8 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -283,6 +283,7 @@ enum imsm_update_type {
 	update_activate_spare,
 	update_create_array,
 	update_kill_array,
+	update_rename_array,
 	update_add_disk,
 };
 
@@ -309,6 +310,12 @@ struct imsm_update_kill_array {
 	int dev_idx;
 };
 
+struct imsm_update_rename_array {
+	enum imsm_update_type type;
+	__u8 name[MAX_RAID_SERIAL_LEN];
+	int dev_idx;
+};
+
 struct imsm_update_add_disk {
 	enum imsm_update_type type;
 };
@@ -2939,6 +2946,30 @@ static void imsm_update_version_info(struct intel_super *super)
 	}
 }
 
+static int check_name(struct intel_super *super, char *name, int quiet)
+{
+	struct imsm_super *mpb = super->anchor;
+	char *reason = NULL;
+	int i;
+
+	if (strlen(name) > MAX_RAID_SERIAL_LEN)
+		reason = "must be 16 characters or less";
+
+	for (i = 0; i < mpb->num_raid_devs; i++) {
+		struct imsm_dev *dev = get_imsm_dev(super, i);
+
+		if (strncmp((char *) dev->volume, name, MAX_RAID_SERIAL_LEN) == 0) {
+			reason = "already exists";
+			break;
+		}
+	}
+
+	if (reason && !quiet)
+		fprintf(stderr, Name ": imsm volume name %s\n", reason);
+
+	return !reason;
+}
+
 static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
 				  unsigned long long size, char *name,
 				  char *homehost, int *uuid)
@@ -2990,16 +3021,8 @@ static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
 	if (super->current_vol == 0)
 		mpb->num_disks = 0;
 
-	for (i = 0; i < super->current_vol; i++) {
-		dev = get_imsm_dev(super, i);
-		if (strncmp((char *) dev->volume, name,
-			     MAX_RAID_SERIAL_LEN) == 0) {
-			fprintf(stderr, Name": '%s' is already defined for this container\n",
-				name);
-			return 0;
-		}
-	}
-
+	if (!check_name(super, name, 0))
+		return 0;
 	sprintf(st->subarray, "%d", idx);
 	dv = malloc(sizeof(*dv));
 	if (!dv) {
@@ -4107,6 +4130,54 @@ static int kill_subarray_imsm(struct supertype *st)
 
 	return 0;
 }
+
+static int update_subarray_imsm(struct supertype *st, char *update, mddev_ident_t ident)
+{
+	/* update the subarray currently referenced by ->current_vol */
+	struct intel_super *super = st->sb;
+	struct imsm_super *mpb = super->anchor;
+
+	if (super->current_vol < 0)
+		return 2;
+
+	if (strcmp(update, "name") == 0) {
+		char *name = ident->name;
+
+		if (is_subarray_active(st->subarray, st->devname)) {
+			fprintf(stderr,
+				Name ": Unable to update name of active subarray\n");
+			return 2;
+		}
+
+		if (!check_name(super, name, 0))
+			return 2;
+
+		if (st->update_tail) {
+			struct imsm_update_rename_array *u = malloc(sizeof(*u));
+
+			if (!u)
+				return 2;
+			u->type = update_rename_array;
+			u->dev_idx = super->current_vol;
+			snprintf((char *) u->name, MAX_RAID_SERIAL_LEN, "%s", name);
+			append_metadata_update(st, u, sizeof(*u));
+		} else {
+			struct imsm_dev *dev;
+			int i;
+
+			dev = get_imsm_dev(super, super->current_vol);
+			snprintf((char *) dev->volume, MAX_RAID_SERIAL_LEN, "%s", name);
+			for (i = 0; i < mpb->num_raid_devs; i++) {
+				dev = get_imsm_dev(super, i);
+				handle_missing(super, dev);
+			}
+			super->updates_pending++;
+		}
+	} else
+		return 2;
+
+	return 0;
+}
 #endif /* MDASSEMBLE */
 
 static int is_rebuilding(struct imsm_dev *dev)
@@ -5217,6 +5288,31 @@ static void imsm_process_update(struct supertype *st,
 		super->updates_pending++;
 		break;
 	}
+	case update_rename_array: {
+		struct imsm_update_rename_array *u = (void *) update->buf;
+		char name[MAX_RAID_SERIAL_LEN+1];
+		int target = u->dev_idx;
+		struct active_array *a;
+		struct imsm_dev *dev;
+
+		/* sanity check that we are not affecting the uuid of
+		 * an active array
+		 */
+		snprintf(name, MAX_RAID_SERIAL_LEN, "%s", (char *) u->name);
+		name[MAX_RAID_SERIAL_LEN] = '\0';
+		for (a = st->arrays; a; a = a->next)
+			if (a->info.container_member == target)
+				break;
+		dev = get_imsm_dev(super, u->dev_idx);
+		if (a || !dev || !check_name(super, name, 1)) {
+			dprintf("failed to rename subarray-%d\n", target);
+			break;
+		}
+
+		snprintf((char *) dev->volume, MAX_RAID_SERIAL_LEN, name);
+		super->updates_pending++;
+		break;
+	}
 	case update_add_disk:
 
 		/* we may be able to repair some arrays if disks are
@@ -5393,6 +5489,7 @@ struct superswitch super_imsm = {
 	.add_to_super	= add_to_super_imsm,
 	.detail_platform = detail_platform_imsm,
 	.kill_subarray = kill_subarray_imsm,
+	.update_subarray = update_subarray_imsm,
 #endif
 	.match_home	= match_home_imsm,
 	.uuid_from_super= uuid_from_super_imsm,