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(&deferred_bios, &era->deferred_bios);  in process_deferred_bios()
1276 	bio_list_init(&era->deferred_bios);  in process_deferred_bios()
1277 	spin_unlock(&era->deferred_lock);  in process_deferred_bios()
1283 		r = writeset_test_and_set(&era->md->bitset_info, ws,  in process_deferred_bios()
1284 					  get_block(era, bio));  in process_deferred_bios()
1298 		r = metadata_commit(era->md);  in process_deferred_bios()
1314 				set_bit(get_block(era, bio), ws->bits);  in process_deferred_bios()
1321 static void process_rpc_calls(struct era *era)  in process_rpc_calls()  argument
1329 	spin_lock(&era->rpc_lock);  in process_rpc_calls()
1330 	list_splice_init(&era->rpc_calls, &calls);  in process_rpc_calls()
1331 	spin_unlock(&era->rpc_lock);  in process_rpc_calls()
1334 		rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg);  in process_rpc_calls()
1339 		r = metadata_commit(era->md);  in process_rpc_calls()
1349 static void kick_off_digest(struct era *era)  in kick_off_digest()  argument
1351 	if (era->md->archived_writesets) {  in kick_off_digest()
1352 		era->md->archived_writesets = false;  in kick_off_digest()
1353 		metadata_digest_start(era->md, &era->digest);  in kick_off_digest()
1359 	struct era *era = container_of(ws, struct era, worker);  in do_work()  local
1361 	kick_off_digest(era);  in do_work()
1362 	process_old_eras(era);  in do_work()
1363 	process_deferred_bios(era);  in do_work()
1364 	process_rpc_calls(era);  in do_work()
1367 static void defer_bio(struct era *era, struct bio *bio)  in defer_bio()  argument
1369 	spin_lock(&era->deferred_lock);  in defer_bio()
1370 	bio_list_add(&era->deferred_bios, bio);  in defer_bio()
1371 	spin_unlock(&era->deferred_lock);  in defer_bio()
1373 	wake_worker(era);  in defer_bio()
1379 static int perform_rpc(struct era *era, struct rpc *rpc)  in perform_rpc()  argument
1384 	spin_lock(&era->rpc_lock);  in perform_rpc()
1385 	list_add(&rpc->list, &era->rpc_calls);  in perform_rpc()
1386 	spin_unlock(&era->rpc_lock);  in perform_rpc()
1388 	wake_worker(era);  in perform_rpc()
1394 static int in_worker0(struct era *era, int (*fn)(struct era_metadata *md))  in in_worker0()  argument
1401 	return perform_rpc(era, &rpc);  in in_worker0()
1404 static int in_worker1(struct era *era,  in in_worker1()  argument
1413 	return perform_rpc(era, &rpc);  in in_worker1()
1416 static void start_worker(struct era *era)  in start_worker()  argument
1418 	atomic_set(&era->suspended, 0);  in start_worker()
1421 static void stop_worker(struct era *era)  in stop_worker()  argument
1423 	atomic_set(&era->suspended, 1);  in stop_worker()
1424 	drain_workqueue(era->wq);  in stop_worker()
1432 static void era_destroy(struct era *era)  in era_destroy()  argument
1434 	if (era->md)  in era_destroy()
1435 		metadata_close(era->md);  in era_destroy()
1437 	if (era->wq)  in era_destroy()
1438 		destroy_workqueue(era->wq);  in era_destroy()
1440 	if (era->origin_dev)  in era_destroy()
1441 		dm_put_device(era->ti, era->origin_dev);  in era_destroy()
1443 	if (era->metadata_dev)  in era_destroy()
1444 		dm_put_device(era->ti, era->metadata_dev);  in era_destroy()
1446 	kfree(era);  in era_destroy()
1449 static dm_block_t calc_nr_blocks(struct era *era)  in calc_nr_blocks()  argument
1451 	return dm_sector_div_up(era->ti->len, era->sectors_per_block);  in calc_nr_blocks()
1469 	struct era *era;  in era_ctr()  local
1477 	era = kzalloc(sizeof(*era), GFP_KERNEL);  in era_ctr()
1478 	if (!era) {  in era_ctr()
1479 		ti->error = "Error allocating era structure";  in era_ctr()
1483 	era->ti = ti;  in era_ctr()
1486 			  &era->metadata_dev);  in era_ctr()
1489 		era_destroy(era);  in era_ctr()
1494 			  &era->origin_dev);  in era_ctr()
1497 		era_destroy(era);  in era_ctr()
1501 	r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy);  in era_ctr()
1504 		era_destroy(era);  in era_ctr()
1508 	r = dm_set_target_max_io_len(ti, era->sectors_per_block);  in era_ctr()
1511 		era_destroy(era);  in era_ctr()
1515 	if (!valid_block_size(era->sectors_per_block)) {  in era_ctr()
1517 		era_destroy(era);  in era_ctr()
1520 	if (era->sectors_per_block & (era->sectors_per_block - 1))  in era_ctr()
1521 		era->sectors_per_block_shift = -1;  in era_ctr()
1523 		era->sectors_per_block_shift = __ffs(era->sectors_per_block);  in era_ctr()
1525 	md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true);  in era_ctr()
1528 		era_destroy(era);  in era_ctr()
1531 	era->md = md;  in era_ctr()
1533 	era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);  in era_ctr()
1534 	if (!era->wq) {  in era_ctr()
1536 		era_destroy(era);  in era_ctr()
1539 	INIT_WORK(&era->worker, do_work);  in era_ctr()
1541 	spin_lock_init(&era->deferred_lock);  in era_ctr()
1542 	bio_list_init(&era->deferred_bios);  in era_ctr()
1544 	spin_lock_init(&era->rpc_lock);  in era_ctr()
1545 	INIT_LIST_HEAD(&era->rpc_calls);  in era_ctr()
1547 	ti->private = era;  in era_ctr()
1563 	struct era *era = ti->private;  in era_map()  local
1564 	dm_block_t block = get_block(era, bio);  in era_map()
1569 	 * block is marked in this era.  in era_map()
1571 	remap_to_origin(era, bio);  in era_map()
1578 	    !metadata_current_marked(era->md, block)) {  in era_map()
1579 		defer_bio(era, bio);  in era_map()
1589 	struct era *era = ti->private;  in era_postsuspend()  local
1591 	r = in_worker0(era, metadata_era_archive);  in era_postsuspend()
1593 		DMERR("%s: couldn't archive current era", __func__);  in era_postsuspend()
1597 	stop_worker(era);  in era_postsuspend()
1599 	r = metadata_commit(era->md);  in era_postsuspend()
1609 	struct era *era = ti->private;  in era_preresume()  local
1610 	dm_block_t new_size = calc_nr_blocks(era);  in era_preresume()
1612 	if (era->nr_blocks != new_size) {  in era_preresume()
1613 		r = metadata_resize(era->md, &new_size);  in era_preresume()
1619 		r = metadata_commit(era->md);  in era_preresume()
1625 		era->nr_blocks = new_size;  in era_preresume()
1628 	start_worker(era);  in era_preresume()
1630 	r = in_worker0(era, metadata_era_rollover);  in era_preresume()
1643  * <current era> <held metadata root | '-'>
1649 	struct era *era = ti->private;  in era_status()  local
1656 		r = in_worker1(era, metadata_get_stats, &stats);  in era_status()
1664 		       (unsigned int) stats.era);  in era_status()
1673 		format_dev_t(buf, era->metadata_dev->bdev->bd_dev);  in era_status()
1675 		format_dev_t(buf, era->origin_dev->bdev->bd_dev);  in era_status()
1676 		DMEMIT("%s %u", buf, era->sectors_per_block);  in era_status()
1693 	struct era *era = ti->private;  in era_message()  local
1701 		return in_worker0(era, metadata_checkpoint);  in era_message()
1704 		return in_worker0(era, metadata_take_snap);  in era_message()
1707 		return in_worker0(era, metadata_drop_snap);  in era_message()
1721 	struct era *era = ti->private;  in era_iterate_devices()  local
1723 	return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data);  in era_iterate_devices()
1728 	struct era *era = ti->private;  in era_io_hints()  local
1733 	 * era device's blocksize (io_opt is a factor) do not override them.  in era_io_hints()
1735 	if (io_opt_sectors < era->sectors_per_block ||  in era_io_hints()
1736 	    do_div(io_opt_sectors, era->sectors_per_block)) {  in era_io_hints()
1738 		blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT);  in era_io_hints()
1745 	.name = "era",
1758 module_dm(era);
1760 MODULE_DESCRIPTION(DM_NAME " era target");