15 #define DM_MSG_PREFIX "era"
47  * after digesting into the era array.
216 		DMERR("Era metadata version %u found, but only versions between %u and %u supported.",  in check_metadata_version()
283 	 * We preallocate 2 writesets.  When an era rolls over we
467 		DMERR("couldn't create era array");  in create_fresh_metadata()
674  * Writesets get 'digested' into the main era array.
682 	uint32_t era;  member
698 	uint64_t key = d->era;  in metadata_digest_remove_writeset()
759 	d->era = key;  in metadata_digest_lookup_writeset()
962 		DMERR("%s: new era failed", __func__);  in metadata_era_rollover()
1030  * Metadata snapshots allow userland to access era data.
1044 		DMERR("%s: era rollover failed", __func__);  in metadata_take_snap()
1078 		DMERR("%s: couldn't inc era tree root", __func__);  in metadata_take_snap()
1126 		DMERR("%s: error deleting era array clone", __func__);  in metadata_drop_snap()
1141 	uint32_t era;  member
1165 	s->era = md->current_era;  in metadata_get_stats()
1172 struct era {  struct
1212 static bool block_size_is_power_of_two(struct era *era)  in block_size_is_power_of_two()  argument
1214 	return era->sectors_per_block_shift >= 0;  in block_size_is_power_of_two()
1217 static dm_block_t get_block(struct era *era, struct bio *bio)  in get_block()  argument
1221 	if (!block_size_is_power_of_two(era))  in get_block()
1222 		(void) sector_div(block_nr, era->sectors_per_block);  in get_block()
1224 		block_nr >>= era->sectors_per_block_shift;  in get_block()
1229 static void remap_to_origin(struct era *era, struct bio *bio)  in remap_to_origin()  argument
1231 	bio_set_dev(bio, era->origin_dev->bdev);  in remap_to_origin()
1239 static void wake_worker(struct era *era)  in wake_worker()  argument
1241 	if (!atomic_read(&era->suspended))  in wake_worker()
1242 		queue_work(era->wq, &era->worker);  in wake_worker()
1245 static void process_old_eras(struct era *era)  in process_old_eras()  argument
1249 	if (!era->digest.step)  in process_old_eras()
1252 	r = era->digest.step(era->md, &era->digest);  in process_old_eras()
1255 		era->digest.step = NULL;  in process_old_eras()
1257 	} else if (era->digest.step)  in process_old_eras()
1258 		wake_worker(era);  in process_old_eras()
1261 static void process_deferred_bios(struct era *era)  in process_deferred_bios()  argument
1269 	struct writeset *ws = era->md->current_writeset;  in process_deferred_bios()
1274 	spin_lock(&era->deferred_lock);  in process_deferred_bios()
1275 	bio_list_merge_init(&deferred_bios, &era->deferred_bios);  in process_deferred_bios()
1276 	spin_unlock(&era->deferred_lock);  in process_deferred_bios()
1282 		r = writeset_test_and_set(&era->md->bitset_info, ws,  in process_deferred_bios()
1283 					  get_block(era, bio));  in process_deferred_bios()
1297 		r = metadata_commit(era->md);  in process_deferred_bios()
1313 				set_bit(get_block(era, bio), ws->bits);  in process_deferred_bios()
1320 static void process_rpc_calls(struct era *era)  in process_rpc_calls()  argument
1328 	spin_lock(&era->rpc_lock);  in process_rpc_calls()
1329 	list_splice_init(&era->rpc_calls, &calls);  in process_rpc_calls()
1330 	spin_unlock(&era->rpc_lock);  in process_rpc_calls()
1333 		rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg);  in process_rpc_calls()
1338 		r = metadata_commit(era->md);  in process_rpc_calls()
1348 static void kick_off_digest(struct era *era)  in kick_off_digest()  argument
1350 	if (era->md->archived_writesets) {  in kick_off_digest()
1351 		era->md->archived_writesets = false;  in kick_off_digest()
1352 		metadata_digest_start(era->md, &era->digest);  in kick_off_digest()
1358 	struct era *era = container_of(ws, struct era, worker);  in do_work()  local
1360 	kick_off_digest(era);  in do_work()
1361 	process_old_eras(era);  in do_work()
1362 	process_deferred_bios(era);  in do_work()
1363 	process_rpc_calls(era);  in do_work()
1366 static void defer_bio(struct era *era, struct bio *bio)  in defer_bio()  argument
1368 	spin_lock(&era->deferred_lock);  in defer_bio()
1369 	bio_list_add(&era->deferred_bios, bio);  in defer_bio()
1370 	spin_unlock(&era->deferred_lock);  in defer_bio()
1372 	wake_worker(era);  in defer_bio()
1378 static int perform_rpc(struct era *era, struct rpc *rpc)  in perform_rpc()  argument
1383 	spin_lock(&era->rpc_lock);  in perform_rpc()
1384 	list_add(&rpc->list, &era->rpc_calls);  in perform_rpc()
1385 	spin_unlock(&era->rpc_lock);  in perform_rpc()
1387 	wake_worker(era);  in perform_rpc()
1393 static int in_worker0(struct era *era, int (*fn)(struct era_metadata *md))  in in_worker0()  argument
1400 	return perform_rpc(era, &rpc);  in in_worker0()
1403 static int in_worker1(struct era *era,  in in_worker1()  argument
1412 	return perform_rpc(era, &rpc);  in in_worker1()
1415 static void start_worker(struct era *era)  in start_worker()  argument
1417 	atomic_set(&era->suspended, 0);  in start_worker()
1420 static void stop_worker(struct era *era)  in stop_worker()  argument
1422 	atomic_set(&era->suspended, 1);  in stop_worker()
1423 	drain_workqueue(era->wq);  in stop_worker()
1431 static void era_destroy(struct era *era)  in era_destroy()  argument
1433 	if (era->md)  in era_destroy()
1434 		metadata_close(era->md);  in era_destroy()
1436 	if (era->wq)  in era_destroy()
1437 		destroy_workqueue(era->wq);  in era_destroy()
1439 	if (era->origin_dev)  in era_destroy()
1440 		dm_put_device(era->ti, era->origin_dev);  in era_destroy()
1442 	if (era->metadata_dev)  in era_destroy()
1443 		dm_put_device(era->ti, era->metadata_dev);  in era_destroy()
1445 	kfree(era);  in era_destroy()
1448 static dm_block_t calc_nr_blocks(struct era *era)  in calc_nr_blocks()  argument
1450 	return dm_sector_div_up(era->ti->len, era->sectors_per_block);  in calc_nr_blocks()
1468 	struct era *era;  in era_ctr()  local
1476 	era = kzalloc(sizeof(*era), GFP_KERNEL);  in era_ctr()
1477 	if (!era) {  in era_ctr()
1478 		ti->error = "Error allocating era structure";  in era_ctr()
1482 	era->ti = ti;  in era_ctr()
1485 			  &era->metadata_dev);  in era_ctr()
1488 		era_destroy(era);  in era_ctr()
1493 			  &era->origin_dev);  in era_ctr()
1496 		era_destroy(era);  in era_ctr()
1500 	r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy);  in era_ctr()
1503 		era_destroy(era);  in era_ctr()
1507 	r = dm_set_target_max_io_len(ti, era->sectors_per_block);  in era_ctr()
1510 		era_destroy(era);  in era_ctr()
1514 	if (!valid_block_size(era->sectors_per_block)) {  in era_ctr()
1516 		era_destroy(era);  in era_ctr()
1519 	if (era->sectors_per_block & (era->sectors_per_block - 1))  in era_ctr()
1520 		era->sectors_per_block_shift = -1;  in era_ctr()
1522 		era->sectors_per_block_shift = __ffs(era->sectors_per_block);  in era_ctr()
1524 	md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true);  in era_ctr()
1527 		era_destroy(era);  in era_ctr()
1530 	era->md = md;  in era_ctr()
1532 	era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);  in era_ctr()
1533 	if (!era->wq) {  in era_ctr()
1535 		era_destroy(era);  in era_ctr()
1538 	INIT_WORK(&era->worker, do_work);  in era_ctr()
1540 	spin_lock_init(&era->deferred_lock);  in era_ctr()
1541 	bio_list_init(&era->deferred_bios);  in era_ctr()
1543 	spin_lock_init(&era->rpc_lock);  in era_ctr()
1544 	INIT_LIST_HEAD(&era->rpc_calls);  in era_ctr()
1546 	ti->private = era;  in era_ctr()
1562 	struct era *era = ti->private;  in era_map()  local
1563 	dm_block_t block = get_block(era, bio);  in era_map()
1568 	 * block is marked in this era.  in era_map()
1570 	remap_to_origin(era, bio);  in era_map()
1577 	    !metadata_current_marked(era->md, block)) {  in era_map()
1578 		defer_bio(era, bio);  in era_map()
1588 	struct era *era = ti->private;  in era_postsuspend()  local
1590 	r = in_worker0(era, metadata_era_archive);  in era_postsuspend()
1592 		DMERR("%s: couldn't archive current era", __func__);  in era_postsuspend()
1596 	stop_worker(era);  in era_postsuspend()
1598 	r = metadata_commit(era->md);  in era_postsuspend()
1608 	struct era *era = ti->private;  in era_preresume()  local
1609 	dm_block_t new_size = calc_nr_blocks(era);  in era_preresume()
1611 	if (era->nr_blocks != new_size) {  in era_preresume()
1612 		r = metadata_resize(era->md, &new_size);  in era_preresume()
1618 		r = metadata_commit(era->md);  in era_preresume()
1624 		era->nr_blocks = new_size;  in era_preresume()
1627 	start_worker(era);  in era_preresume()
1629 	r = in_worker0(era, metadata_era_rollover);  in era_preresume()
1642  * <current era> <held metadata root | '-'>
1648 	struct era *era = ti->private;  in era_status()  local
1655 		r = in_worker1(era, metadata_get_stats, &stats);  in era_status()
1663 		       (unsigned int) stats.era);  in era_status()
1672 		format_dev_t(buf, era->metadata_dev->bdev->bd_dev);  in era_status()
1674 		format_dev_t(buf, era->origin_dev->bdev->bd_dev);  in era_status()
1675 		DMEMIT("%s %u", buf, era->sectors_per_block);  in era_status()
1692 	struct era *era = ti->private;  in era_message()  local
1700 		return in_worker0(era, metadata_checkpoint);  in era_message()
1703 		return in_worker0(era, metadata_take_snap);  in era_message()
1706 		return in_worker0(era, metadata_drop_snap);  in era_message()
1720 	struct era *era = ti->private;  in era_iterate_devices()  local
1722 	return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data);  in era_iterate_devices()
1727 	struct era *era = ti->private;  in era_io_hints()  local
1732 	 * era device's blocksize (io_opt is a factor) do not override them.  in era_io_hints()
1734 	if (io_opt_sectors < era->sectors_per_block ||  in era_io_hints()
1735 	    do_div(io_opt_sectors, era->sectors_per_block)) {  in era_io_hints()
1737 		limits->io_opt = era->sectors_per_block << SECTOR_SHIFT;  in era_io_hints()
1744 	.name = "era",
1757 module_dm(era);
1759 MODULE_DESCRIPTION(DM_NAME " era target");