bcache: add set_uuid in struct cache_set

This patch adds a separated set_uuid[16] in struct cache_set, to store
the uuid of the cache set. This is the preparation to remove the
embedded struct cache_sb from struct cache_set.

Signed-off-by: Coly Li <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/md/bcache/bcache.h

···
 	struct mutex		verify_lock;
 #endif
 
+	uint8_t			set_uuid[16];
 	unsigned int		nr_uuids;
 	struct uuid_entry	*uuids;
 	BKEY_PADDED(uuid_bucket);

drivers/md/bcache/debug.c

···
 	if (!IS_ERR_OR_NULL(bcache_debug)) {
 		char name[50];
 
-		snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
+		snprintf(name, 50, "bcache-%pU", c->set_uuid);
 		c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
 					       &cache_set_debug_ops);
 	}

drivers/md/bcache/super.c

···
 	struct cached_dev *exist_dc, *t;
 	int ret = 0;
 
-	if ((set_uuid && memcmp(set_uuid, c->sb.set_uuid, 16)) ||
-	    (!set_uuid && memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16)))
+	if ((set_uuid && memcmp(set_uuid, c->set_uuid, 16)) ||
+	    (!set_uuid && memcmp(dc->sb.set_uuid, c->set_uuid, 16)))
 		return -ENOENT;
 
 	if (dc->disk.c) {
···
 		u->first_reg = u->last_reg = rtime;
 		bch_uuid_write(c);
 
-		memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16);
+		memcpy(dc->sb.set_uuid, c->set_uuid, 16);
 		SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
 
 		bch_write_bdev_super(dc, &cl);
···
 	pr_info("Caching %s as %s on set %pU\n",
 		dc->backing_dev_name,
 		dc->disk.disk->disk_name,
-		dc->disk.c->sb.set_uuid);
+		dc->disk.c->set_uuid);
 	return 0;
 }
 
···
 	vaf.va = &args;
 
 	pr_err("error on %pU: %pV, disabling caching\n",
-	       c->sb.set_uuid, &vaf);
+	       c->set_uuid, &vaf);
 
 	va_end(args);
 
···
 	list_del(&c->list);
 	mutex_unlock(&bch_register_lock);
 
-	pr_info("Cache set %pU unregistered\n", c->sb.set_uuid);
+	pr_info("Cache set %pU unregistered\n", c->set_uuid);
 	wake_up(&unregister_wait);
 
 	closure_debug_destroy(&c->cl);
···
 {
 	if (dc->stop_when_cache_set_failed == BCH_CACHED_DEV_STOP_ALWAYS) {
 		pr_warn("stop_when_cache_set_failed of %s is \"always\", stop it for failed cache set %pU.\n",
-			d->disk->disk_name, c->sb.set_uuid);
+			d->disk->disk_name, c->set_uuid);
 		bcache_device_stop(d);
 	} else if (atomic_read(&dc->has_dirty)) {
 		/*
···
 
 	bch_cache_accounting_init(&c->accounting, &c->cl);
 
-	memcpy(c->sb.set_uuid, sb->set_uuid, 16);
+	memcpy(c->set_uuid, sb->set_uuid, 16);
 	c->sb.block_size	= sb->block_size;
 	c->sb.bucket_size	= sb->bucket_size;
 	c->sb.nr_in_set		= sb->nr_in_set;
···
 	struct cache_set *c;
 
 	list_for_each_entry(c, &bch_cache_sets, list)
-		if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) {
+		if (!memcmp(c->set_uuid, ca->sb.set_uuid, 16)) {
 			if (c->cache)
 				return "duplicate cache set member";
 
···
 		return err;
 
 	err = "error creating kobject";
-	if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) ||
+	if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->set_uuid) ||
 	    kobject_add(&c->internal, &c->kobj, "internal"))
 		goto err;
 
···
 	 */
 	if (ca->sb.seq > c->sb.seq || c->sb.seq == 0) {
 		c->sb.version		= ca->sb.version;
-		memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
+		memcpy(c->set_uuid, ca->sb.set_uuid, 16);
 		c->sb.flags             = ca->sb.flags;
 		c->sb.seq		= ca->sb.seq;
 		pr_debug("set version = %llu\n", c->sb.version);
···
 	list_for_each_entry_safe(pdev, tpdev, &pending_devs, list) {
 		list_for_each_entry_safe(c, tc, &bch_cache_sets, list) {
 			char *pdev_set_uuid = pdev->dc->sb.set_uuid;
-			char *set_uuid = c->sb.uuid;
+			char *set_uuid = c->set_uuid;
 
 			if (!memcmp(pdev_set_uuid, set_uuid, 16)) {
 				list_del(&pdev->list);

include/trace/events/bcache.h

···
 	),
 
 	TP_fast_assign(
-		memcpy(__entry->uuid, c->sb.set_uuid, 16);
+		memcpy(__entry->uuid, c->set_uuid, 16);
 		__entry->inode		= inode;
 		__entry->sector		= bio->bi_iter.bi_sector;
 		__entry->nr_sector	= bio->bi_iter.bi_size >> 9;
···
 	),
 
 	TP_fast_assign(
-		memcpy(__entry->uuid, c->sb.set_uuid, 16);
+		memcpy(__entry->uuid, c->set_uuid, 16);
 	),
 
 	TP_printk("%pU", __entry->uuid)