From 3b1a94c88b798d4f3bd1a5b61f5c8fb9d987c242 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Wed, 7 Jun 2017 15:55:39 +0900 Subject: dm zoned: drive-managed zoned block device target The dm-zoned device mapper target provides transparent write access to zoned block devices (ZBC and ZAC compliant block devices). dm-zoned hides to the device user (a file system or an application doing raw block device accesses) any constraint imposed on write requests by the device, equivalent to a drive-managed zoned block device model. Write requests are processed using a combination of on-disk buffering using the device conventional zones and direct in-place processing for requests aligned to a zone sequential write pointer position. A background reclaim process implemented using dm_kcopyd_copy ensures that conventional zones are always available for executing unaligned write requests. The reclaim process overhead is minimized by managing buffer zones in a least-recently-written order and first targeting the oldest buffer zones. Doing so, blocks under regular write access (such as metadata blocks of a file system) remain stored in conventional zones, resulting in no apparent overhead. dm-zoned implementation focus on simplicity and on minimizing overhead (CPU, memory and storage overhead). For a 14TB host-managed disk with 256 MB zones, dm-zoned memory usage per disk instance is at most about 3 MB and as little as 5 zones will be used internally for storing metadata and performing buffer zone reclaim operations. This is achieved using zone level indirection rather than a full block indirection system for managing block movement between zones. dm-zoned primary target is host-managed zoned block devices but it can also be used with host-aware device models to mitigate potential device-side performance degradation due to excessive random writing. Zoned block devices can be formatted and checked for use with the dm-zoned target using the dmzadm utility available at: https://github.com/hgst/dm-zoned-tools Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Bart Van Assche [Mike Snitzer partly refactored Damien's original work to cleanup the code] Signed-off-by: Mike Snitzer --- drivers/md/dm-zoned-target.c | 967 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 967 insertions(+) create mode 100644 drivers/md/dm-zoned-target.c (limited to 'drivers/md/dm-zoned-target.c') diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c new file mode 100644 index 000000000000..2b538fa817f4 --- /dev/null +++ b/drivers/md/dm-zoned-target.c @@ -0,0 +1,967 @@ +/* + * Copyright (C) 2017 Western Digital Corporation or its affiliates. + * + * This file is released under the GPL. + */ + +#include "dm-zoned.h" + +#include + +#define DM_MSG_PREFIX "zoned" + +#define DMZ_MIN_BIOS 8192 + +/* + * Zone BIO context. + */ +struct dmz_bioctx { + struct dmz_target *target; + struct dm_zone *zone; + struct bio *bio; + atomic_t ref; + blk_status_t status; +}; + +/* + * Chunk work descriptor. + */ +struct dm_chunk_work { + struct work_struct work; + atomic_t refcount; + struct dmz_target *target; + unsigned int chunk; + struct bio_list bio_list; +}; + +/* + * Target descriptor. + */ +struct dmz_target { + struct dm_dev *ddev; + + unsigned long flags; + + /* Zoned block device information */ + struct dmz_dev *dev; + + /* For metadata handling */ + struct dmz_metadata *metadata; + + /* For reclaim */ + struct dmz_reclaim *reclaim; + + /* For chunk work */ + struct mutex chunk_lock; + struct radix_tree_root chunk_rxtree; + struct workqueue_struct *chunk_wq; + + /* For cloned BIOs to zones */ + struct bio_set *bio_set; + + /* For flush */ + spinlock_t flush_lock; + struct bio_list flush_list; + struct delayed_work flush_work; + struct workqueue_struct *flush_wq; +}; + +/* + * Flush intervals (seconds). + */ +#define DMZ_FLUSH_PERIOD (10 * HZ) + +/* + * Target BIO completion. + */ +static inline void dmz_bio_endio(struct bio *bio, blk_status_t status) +{ + struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx)); + + if (bioctx->status == BLK_STS_OK && status != BLK_STS_OK) + bioctx->status = status; + bio_endio(bio); +} + +/* + * Partial clone read BIO completion callback. This terminates the + * target BIO when there are no more references to its context. + */ +static void dmz_read_bio_end_io(struct bio *bio) +{ + struct dmz_bioctx *bioctx = bio->bi_private; + blk_status_t status = bio->bi_status; + + bio_put(bio); + dmz_bio_endio(bioctx->bio, status); +} + +/* + * Issue a BIO to a zone. The BIO may only partially process the + * original target BIO. + */ +static int dmz_submit_read_bio(struct dmz_target *dmz, struct dm_zone *zone, + struct bio *bio, sector_t chunk_block, + unsigned int nr_blocks) +{ + struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx)); + sector_t sector; + struct bio *clone; + + /* BIO remap sector */ + sector = dmz_start_sect(dmz->metadata, zone) + dmz_blk2sect(chunk_block); + + /* If the read is not partial, there is no need to clone the BIO */ + if (nr_blocks == dmz_bio_blocks(bio)) { + /* Setup and submit the BIO */ + bio->bi_iter.bi_sector = sector; + atomic_inc(&bioctx->ref); + generic_make_request(bio); + return 0; + } + + /* Partial BIO: we need to clone the BIO */ + clone = bio_clone_fast(bio, GFP_NOIO, dmz->bio_set); + if (!clone) + return -ENOMEM; + + /* Setup the clone */ + clone->bi_iter.bi_sector = sector; + clone->bi_iter.bi_size = dmz_blk2sect(nr_blocks) << SECTOR_SHIFT; + clone->bi_end_io = dmz_read_bio_end_io; + clone->bi_private = bioctx; + + bio_advance(bio, clone->bi_iter.bi_size); + + /* Submit the clone */ + atomic_inc(&bioctx->ref); + generic_make_request(clone); + + return 0; +} + +/* + * Zero out pages of discarded blocks accessed by a read BIO. + */ +static void dmz_handle_read_zero(struct dmz_target *dmz, struct bio *bio, + sector_t chunk_block, unsigned int nr_blocks) +{ + unsigned int size = nr_blocks << DMZ_BLOCK_SHIFT; + + /* Clear nr_blocks */ + swap(bio->bi_iter.bi_size, size); + zero_fill_bio(bio); + swap(bio->bi_iter.bi_size, size); + + bio_advance(bio, size); +} + +/* + * Process a read BIO. + */ +static int dmz_handle_read(struct dmz_target *dmz, struct dm_zone *zone, + struct bio *bio) +{ + sector_t chunk_block = dmz_chunk_block(dmz->dev, dmz_bio_block(bio)); + unsigned int nr_blocks = dmz_bio_blocks(bio); + sector_t end_block = chunk_block + nr_blocks; + struct dm_zone *rzone, *bzone; + int ret; + + /* Read into unmapped chunks need only zeroing the BIO buffer */ + if (!zone) { + zero_fill_bio(bio); + return 0; + } + + dmz_dev_debug(dmz->dev, "READ chunk %llu -> %s zone %u, block %llu, %u blocks", + (unsigned long long)dmz_bio_chunk(dmz->dev, bio), + (dmz_is_rnd(zone) ? "RND" : "SEQ"), + dmz_id(dmz->metadata, zone), + (unsigned long long)chunk_block, nr_blocks); + + /* Check block validity to determine the read location */ + bzone = zone->bzone; + while (chunk_block < end_block) { + nr_blocks = 0; + if (dmz_is_rnd(zone) || chunk_block < zone->wp_block) { + /* Test block validity in the data zone */ + ret = dmz_block_valid(dmz->metadata, zone, chunk_block); + if (ret < 0) + return ret; + if (ret > 0) { + /* Read data zone blocks */ + nr_blocks = ret; + rzone = zone; + } + } + + /* + * No valid blocks found in the data zone. + * Check the buffer zone, if there is one. + */ + if (!nr_blocks && bzone) { + ret = dmz_block_valid(dmz->metadata, bzone, chunk_block); + if (ret < 0) + return ret; + if (ret > 0) { + /* Read buffer zone blocks */ + nr_blocks = ret; + rzone = bzone; + } + } + + if (nr_blocks) { + /* Valid blocks found: read them */ + nr_blocks = min_t(unsigned int, nr_blocks, end_block - chunk_block); + ret = dmz_submit_read_bio(dmz, rzone, bio, chunk_block, nr_blocks); + if (ret) + return ret; + chunk_block += nr_blocks; + } else { + /* No valid block: zeroout the current BIO block */ + dmz_handle_read_zero(dmz, bio, chunk_block, 1); + chunk_block++; + } + } + + return 0; +} + +/* + * Issue a write BIO to a zone. + */ +static void dmz_submit_write_bio(struct dmz_target *dmz, struct dm_zone *zone, + struct bio *bio, sector_t chunk_block, + unsigned int nr_blocks) +{ + struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx)); + + /* Setup and submit the BIO */ + bio->bi_bdev = dmz->dev->bdev; + bio->bi_iter.bi_sector = dmz_start_sect(dmz->metadata, zone) + dmz_blk2sect(chunk_block); + atomic_inc(&bioctx->ref); + generic_make_request(bio); + + if (dmz_is_seq(zone)) + zone->wp_block += nr_blocks; +} + +/* + * Write blocks directly in a data zone, at the write pointer. + * If a buffer zone is assigned, invalidate the blocks written + * in place. + */ +static int dmz_handle_direct_write(struct dmz_target *dmz, + struct dm_zone *zone, struct bio *bio, + sector_t chunk_block, + unsigned int nr_blocks) +{ + struct dmz_metadata *zmd = dmz->metadata; + struct dm_zone *bzone = zone->bzone; + int ret; + + if (dmz_is_readonly(zone)) + return -EROFS; + + /* Submit write */ + dmz_submit_write_bio(dmz, zone, bio, chunk_block, nr_blocks); + + /* + * Validate the blocks in the data zone and invalidate + * in the buffer zone, if there is one. + */ + ret = dmz_validate_blocks(zmd, zone, chunk_block, nr_blocks); + if (ret == 0 && bzone) + ret = dmz_invalidate_blocks(zmd, bzone, chunk_block, nr_blocks); + + return ret; +} + +/* + * Write blocks in the buffer zone of @zone. + * If no buffer zone is assigned yet, get one. + * Called with @zone write locked. + */ +static int dmz_handle_buffered_write(struct dmz_target *dmz, + struct dm_zone *zone, struct bio *bio, + sector_t chunk_block, + unsigned int nr_blocks) +{ + struct dmz_metadata *zmd = dmz->metadata; + struct dm_zone *bzone; + int ret; + + /* Get the buffer zone. One will be allocated if needed */ + bzone = dmz_get_chunk_buffer(zmd, zone); + if (!bzone) + return -ENOSPC; + + if (dmz_is_readonly(bzone)) + return -EROFS; + + /* Submit write */ + dmz_submit_write_bio(dmz, bzone, bio, chunk_block, nr_blocks); + + /* + * Validate the blocks in the buffer zone + * and invalidate in the data zone. + */ + ret = dmz_validate_blocks(zmd, bzone, chunk_block, nr_blocks); + if (ret == 0 && chunk_block < zone->wp_block) + ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks); + + return ret; +} + +/* + * Process a write BIO. + */ +static int dmz_handle_write(struct dmz_target *dmz, struct dm_zone *zone, + struct bio *bio) +{ + sector_t chunk_block = dmz_chunk_block(dmz->dev, dmz_bio_block(bio)); + unsigned int nr_blocks = dmz_bio_blocks(bio); + + if (!zone) + return -ENOSPC; + + dmz_dev_debug(dmz->dev, "WRITE chunk %llu -> %s zone %u, block %llu, %u blocks", + (unsigned long long)dmz_bio_chunk(dmz->dev, bio), + (dmz_is_rnd(zone) ? "RND" : "SEQ"), + dmz_id(dmz->metadata, zone), + (unsigned long long)chunk_block, nr_blocks); + + if (dmz_is_rnd(zone) || chunk_block == zone->wp_block) { + /* + * zone is a random zone or it is a sequential zone + * and the BIO is aligned to the zone write pointer: + * direct write the zone. + */ + return dmz_handle_direct_write(dmz, zone, bio, chunk_block, nr_blocks); + } + + /* + * This is an unaligned write in a sequential zone: + * use buffered write. + */ + return dmz_handle_buffered_write(dmz, zone, bio, chunk_block, nr_blocks); +} + +/* + * Process a discard BIO. + */ +static int dmz_handle_discard(struct dmz_target *dmz, struct dm_zone *zone, + struct bio *bio) +{ + struct dmz_metadata *zmd = dmz->metadata; + sector_t block = dmz_bio_block(bio); + unsigned int nr_blocks = dmz_bio_blocks(bio); + sector_t chunk_block = dmz_chunk_block(dmz->dev, block); + int ret = 0; + + /* For unmapped chunks, there is nothing to do */ + if (!zone) + return 0; + + if (dmz_is_readonly(zone)) + return -EROFS; + + dmz_dev_debug(dmz->dev, "DISCARD chunk %llu -> zone %u, block %llu, %u blocks", + (unsigned long long)dmz_bio_chunk(dmz->dev, bio), + dmz_id(zmd, zone), + (unsigned long long)chunk_block, nr_blocks); + + /* + * Invalidate blocks in the data zone and its + * buffer zone if one is mapped. + */ + if (dmz_is_rnd(zone) || chunk_block < zone->wp_block) + ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks); + if (ret == 0 && zone->bzone) + ret = dmz_invalidate_blocks(zmd, zone->bzone, + chunk_block, nr_blocks); + return ret; +} + +/* + * Process a BIO. + */ +static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw, + struct bio *bio) +{ + struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx)); + struct dmz_metadata *zmd = dmz->metadata; + struct dm_zone *zone; + int ret; + + /* + * Write may trigger a zone allocation. So make sure the + * allocation can succeed. + */ + if (bio_op(bio) == REQ_OP_WRITE) + dmz_schedule_reclaim(dmz->reclaim); + + dmz_lock_metadata(zmd); + + /* + * Get the data zone mapping the chunk. There may be no + * mapping for read and discard. If a mapping is obtained, + + the zone returned will be set to active state. + */ + zone = dmz_get_chunk_mapping(zmd, dmz_bio_chunk(dmz->dev, bio), + bio_op(bio)); + if (IS_ERR(zone)) { + ret = PTR_ERR(zone); + goto out; + } + + /* Process the BIO */ + if (zone) { + dmz_activate_zone(zone); + bioctx->zone = zone; + } + + switch (bio_op(bio)) { + case REQ_OP_READ: + ret = dmz_handle_read(dmz, zone, bio); + break; + case REQ_OP_WRITE: + ret = dmz_handle_write(dmz, zone, bio); + break; + case REQ_OP_DISCARD: + case REQ_OP_WRITE_ZEROES: + ret = dmz_handle_discard(dmz, zone, bio); + break; + default: + dmz_dev_err(dmz->dev, "Unsupported BIO operation 0x%x", + bio_op(bio)); + ret = -EIO; + } + + /* + * Release the chunk mapping. This will check that the mapping + * is still valid, that is, that the zone used still has valid blocks. + */ + if (zone) + dmz_put_chunk_mapping(zmd, zone); +out: + dmz_bio_endio(bio, errno_to_blk_status(ret)); + + dmz_unlock_metadata(zmd); +} + +/* + * Increment a chunk reference counter. + */ +static inline void dmz_get_chunk_work(struct dm_chunk_work *cw) +{ + atomic_inc(&cw->refcount); +} + +/* + * Decrement a chunk work reference count and + * free it if it becomes 0. + */ +static void dmz_put_chunk_work(struct dm_chunk_work *cw) +{ + if (atomic_dec_and_test(&cw->refcount)) { + WARN_ON(!bio_list_empty(&cw->bio_list)); + radix_tree_delete(&cw->target->chunk_rxtree, cw->chunk); + kfree(cw); + } +} + +/* + * Chunk BIO work function. + */ +static void dmz_chunk_work(struct work_struct *work) +{ + struct dm_chunk_work *cw = container_of(work, struct dm_chunk_work, work); + struct dmz_target *dmz = cw->target; + struct bio *bio; + + mutex_lock(&dmz->chunk_lock); + + /* Process the chunk BIOs */ + while ((bio = bio_list_pop(&cw->bio_list))) { + mutex_unlock(&dmz->chunk_lock); + dmz_handle_bio(dmz, cw, bio); + mutex_lock(&dmz->chunk_lock); + dmz_put_chunk_work(cw); + } + + /* Queueing the work incremented the work refcount */ + dmz_put_chunk_work(cw); + + mutex_unlock(&dmz->chunk_lock); +} + +/* + * Flush work. + */ +static void dmz_flush_work(struct work_struct *work) +{ + struct dmz_target *dmz = container_of(work, struct dmz_target, flush_work.work); + struct bio *bio; + int ret; + + /* Flush dirty metadata blocks */ + ret = dmz_flush_metadata(dmz->metadata); + + /* Process queued flush requests */ + while (1) { + spin_lock(&dmz->flush_lock); + bio = bio_list_pop(&dmz->flush_list); + spin_unlock(&dmz->flush_lock); + + if (!bio) + break; + + dmz_bio_endio(bio, errno_to_blk_status(ret)); + } + + queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD); +} + +/* + * Get a chunk work and start it to process a new BIO. + * If the BIO chunk has no work yet, create one. + */ +static void dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio) +{ + unsigned int chunk = dmz_bio_chunk(dmz->dev, bio); + struct dm_chunk_work *cw; + + mutex_lock(&dmz->chunk_lock); + + /* Get the BIO chunk work. If one is not active yet, create one */ + cw = radix_tree_lookup(&dmz->chunk_rxtree, chunk); + if (!cw) { + int ret; + + /* Create a new chunk work */ + cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOFS); + if (!cw) + goto out; + + INIT_WORK(&cw->work, dmz_chunk_work); + atomic_set(&cw->refcount, 0); + cw->target = dmz; + cw->chunk = chunk; + bio_list_init(&cw->bio_list); + + ret = radix_tree_insert(&dmz->chunk_rxtree, chunk, cw); + if (unlikely(ret)) { + kfree(cw); + cw = NULL; + goto out; + } + } + + bio_list_add(&cw->bio_list, bio); + dmz_get_chunk_work(cw); + + if (queue_work(dmz->chunk_wq, &cw->work)) + dmz_get_chunk_work(cw); +out: + mutex_unlock(&dmz->chunk_lock); +} + +/* + * Process a new BIO. + */ +static int dmz_map(struct dm_target *ti, struct bio *bio) +{ + struct dmz_target *dmz = ti->private; + struct dmz_dev *dev = dmz->dev; + struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx)); + sector_t sector = bio->bi_iter.bi_sector; + unsigned int nr_sectors = bio_sectors(bio); + sector_t chunk_sector; + + dmz_dev_debug(dev, "BIO op %d sector %llu + %u => chunk %llu, block %llu, %u blocks", + bio_op(bio), (unsigned long long)sector, nr_sectors, + (unsigned long long)dmz_bio_chunk(dmz->dev, bio), + (unsigned long long)dmz_chunk_block(dmz->dev, dmz_bio_block(bio)), + (unsigned int)dmz_bio_blocks(bio)); + + bio->bi_bdev = dev->bdev; + + if (!nr_sectors && (bio_op(bio) != REQ_OP_FLUSH) && (bio_op(bio) != REQ_OP_WRITE)) + return DM_MAPIO_REMAPPED; + + /* The BIO should be block aligned */ + if ((nr_sectors & DMZ_BLOCK_SECTORS_MASK) || (sector & DMZ_BLOCK_SECTORS_MASK)) + return DM_MAPIO_KILL; + + /* Initialize the BIO context */ + bioctx->target = dmz; + bioctx->zone = NULL; + bioctx->bio = bio; + atomic_set(&bioctx->ref, 1); + bioctx->status = BLK_STS_OK; + + /* Set the BIO pending in the flush list */ + if (bio_op(bio) == REQ_OP_FLUSH || (!nr_sectors && bio_op(bio) == REQ_OP_WRITE)) { + spin_lock(&dmz->flush_lock); + bio_list_add(&dmz->flush_list, bio); + spin_unlock(&dmz->flush_lock); + mod_delayed_work(dmz->flush_wq, &dmz->flush_work, 0); + return DM_MAPIO_SUBMITTED; + } + + /* Split zone BIOs to fit entirely into a zone */ + chunk_sector = sector & (dev->zone_nr_sectors - 1); + if (chunk_sector + nr_sectors > dev->zone_nr_sectors) + dm_accept_partial_bio(bio, dev->zone_nr_sectors - chunk_sector); + + /* Now ready to handle this BIO */ + dmz_reclaim_bio_acc(dmz->reclaim); + dmz_queue_chunk_work(dmz, bio); + + return DM_MAPIO_SUBMITTED; +} + +/* + * Completed target BIO processing. + */ +static int dmz_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error) +{ + struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx)); + + if (bioctx->status == BLK_STS_OK && *error) + bioctx->status = *error; + + if (!atomic_dec_and_test(&bioctx->ref)) + return DM_ENDIO_INCOMPLETE; + + /* Done */ + bio->bi_status = bioctx->status; + + if (bioctx->zone) { + struct dm_zone *zone = bioctx->zone; + + if (*error && bio_op(bio) == REQ_OP_WRITE) { + if (dmz_is_seq(zone)) + set_bit(DMZ_SEQ_WRITE_ERR, &zone->flags); + } + dmz_deactivate_zone(zone); + } + + return DM_ENDIO_DONE; +} + +/* + * Get zoned device information. + */ +static int dmz_get_zoned_device(struct dm_target *ti, char *path) +{ + struct dmz_target *dmz = ti->private; + struct request_queue *q; + struct dmz_dev *dev; + int ret; + + /* Get the target device */ + ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &dmz->ddev); + if (ret) { + ti->error = "Get target device failed"; + dmz->ddev = NULL; + return ret; + } + + dev = kzalloc(sizeof(struct dmz_dev), GFP_KERNEL); + if (!dev) { + ret = -ENOMEM; + goto err; + } + + dev->bdev = dmz->ddev->bdev; + (void)bdevname(dev->bdev, dev->name); + + if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE) { + ti->error = "Not a zoned block device"; + ret = -EINVAL; + goto err; + } + + dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; + if (ti->begin || (ti->len != dev->capacity)) { + ti->error = "Partial mapping not supported"; + ret = -EINVAL; + goto err; + } + + q = bdev_get_queue(dev->bdev); + dev->zone_nr_sectors = q->limits.chunk_sectors; + dev->zone_nr_sectors_shift = ilog2(dev->zone_nr_sectors); + + dev->zone_nr_blocks = dmz_sect2blk(dev->zone_nr_sectors); + dev->zone_nr_blocks_shift = ilog2(dev->zone_nr_blocks); + + dev->nr_zones = (dev->capacity + dev->zone_nr_sectors - 1) + >> dev->zone_nr_sectors_shift; + + dmz->dev = dev; + + return 0; +err: + dm_put_device(ti, dmz->ddev); + kfree(dev); + + return ret; +} + +/* + * Cleanup zoned device information. + */ +static void dmz_put_zoned_device(struct dm_target *ti) +{ + struct dmz_target *dmz = ti->private; + + dm_put_device(ti, dmz->ddev); + kfree(dmz->dev); + dmz->dev = NULL; +} + +/* + * Setup target. + */ +static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct dmz_target *dmz; + struct dmz_dev *dev; + int ret; + + /* Check arguments */ + if (argc != 1) { + ti->error = "Invalid argument count"; + return -EINVAL; + } + + /* Allocate and initialize the target descriptor */ + dmz = kzalloc(sizeof(struct dmz_target), GFP_KERNEL); + if (!dmz) { + ti->error = "Unable to allocate the zoned target descriptor"; + return -ENOMEM; + } + ti->private = dmz; + + /* Get the target zoned block device */ + ret = dmz_get_zoned_device(ti, argv[0]); + if (ret) { + dmz->ddev = NULL; + goto err; + } + + /* Initialize metadata */ + dev = dmz->dev; + ret = dmz_ctr_metadata(dev, &dmz->metadata); + if (ret) { + ti->error = "Metadata initialization failed"; + goto err_dev; + } + + /* Set target (no write same support) */ + ti->max_io_len = dev->zone_nr_sectors << 9; + ti->num_flush_bios = 1; + ti->num_discard_bios = 1; + ti->num_write_zeroes_bios = 1; + ti->per_io_data_size = sizeof(struct dmz_bioctx); + ti->flush_supported = true; + ti->discards_supported = true; + ti->split_discard_bios = true; + + /* The exposed capacity is the number of chunks that can be mapped */ + ti->len = (sector_t)dmz_nr_chunks(dmz->metadata) << dev->zone_nr_sectors_shift; + + /* Zone BIO */ + dmz->bio_set = bioset_create(DMZ_MIN_BIOS, 0, 0); + if (!dmz->bio_set) { + ti->error = "Create BIO set failed"; + ret = -ENOMEM; + goto err_meta; + } + + /* Chunk BIO work */ + mutex_init(&dmz->chunk_lock); + INIT_RADIX_TREE(&dmz->chunk_rxtree, GFP_NOFS); + dmz->chunk_wq = alloc_workqueue("dmz_cwq_%s", WQ_MEM_RECLAIM | WQ_UNBOUND, + 0, dev->name); + if (!dmz->chunk_wq) { + ti->error = "Create chunk workqueue failed"; + ret = -ENOMEM; + goto err_bio; + } + + /* Flush work */ + spin_lock_init(&dmz->flush_lock); + bio_list_init(&dmz->flush_list); + INIT_DELAYED_WORK(&dmz->flush_work, dmz_flush_work); + dmz->flush_wq = alloc_ordered_workqueue("dmz_fwq_%s", WQ_MEM_RECLAIM, + dev->name); + if (!dmz->flush_wq) { + ti->error = "Create flush workqueue failed"; + ret = -ENOMEM; + goto err_cwq; + } + mod_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD); + + /* Initialize reclaim */ + ret = dmz_ctr_reclaim(dev, dmz->metadata, &dmz->reclaim); + if (ret) { + ti->error = "Zone reclaim initialization failed"; + goto err_fwq; + } + + dmz_dev_info(dev, "Target device: %llu 512-byte logical sectors (%llu blocks)", + (unsigned long long)ti->len, + (unsigned long long)dmz_sect2blk(ti->len)); + + return 0; +err_fwq: + destroy_workqueue(dmz->flush_wq); +err_cwq: + destroy_workqueue(dmz->chunk_wq); +err_bio: + bioset_free(dmz->bio_set); +err_meta: + dmz_dtr_metadata(dmz->metadata); +err_dev: + dmz_put_zoned_device(ti); +err: + kfree(dmz); + + return ret; +} + +/* + * Cleanup target. + */ +static void dmz_dtr(struct dm_target *ti) +{ + struct dmz_target *dmz = ti->private; + + flush_workqueue(dmz->chunk_wq); + destroy_workqueue(dmz->chunk_wq); + + dmz_dtr_reclaim(dmz->reclaim); + + cancel_delayed_work_sync(&dmz->flush_work); + destroy_workqueue(dmz->flush_wq); + + (void) dmz_flush_metadata(dmz->metadata); + + dmz_dtr_metadata(dmz->metadata); + + bioset_free(dmz->bio_set); + + dmz_put_zoned_device(ti); + + kfree(dmz); +} + +/* + * Setup target request queue limits. + */ +static void dmz_io_hints(struct dm_target *ti, struct queue_limits *limits) +{ + struct dmz_target *dmz = ti->private; + unsigned int chunk_sectors = dmz->dev->zone_nr_sectors; + + limits->logical_block_size = DMZ_BLOCK_SIZE; + limits->physical_block_size = DMZ_BLOCK_SIZE; + + blk_limits_io_min(limits, DMZ_BLOCK_SIZE); + blk_limits_io_opt(limits, DMZ_BLOCK_SIZE); + + limits->discard_alignment = DMZ_BLOCK_SIZE; + limits->discard_granularity = DMZ_BLOCK_SIZE; + limits->max_discard_sectors = chunk_sectors; + limits->max_hw_discard_sectors = chunk_sectors; + limits->max_write_zeroes_sectors = chunk_sectors; + + /* FS hint to try to align to the device zone size */ + limits->chunk_sectors = chunk_sectors; + limits->max_sectors = chunk_sectors; + + /* We are exposing a drive-managed zoned block device */ + limits->zoned = BLK_ZONED_NONE; +} + +/* + * Pass on ioctl to the backend device. + */ +static int dmz_prepare_ioctl(struct dm_target *ti, + struct block_device **bdev, fmode_t *mode) +{ + struct dmz_target *dmz = ti->private; + + *bdev = dmz->dev->bdev; + + return 0; +} + +/* + * Stop works on suspend. + */ +static void dmz_suspend(struct dm_target *ti) +{ + struct dmz_target *dmz = ti->private; + + flush_workqueue(dmz->chunk_wq); + dmz_suspend_reclaim(dmz->reclaim); + cancel_delayed_work_sync(&dmz->flush_work); +} + +/* + * Restart works on resume or if suspend failed. + */ +static void dmz_resume(struct dm_target *ti) +{ + struct dmz_target *dmz = ti->private; + + queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD); + dmz_resume_reclaim(dmz->reclaim); +} + +static int dmz_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct dmz_target *dmz = ti->private; + + return fn(ti, dmz->ddev, 0, dmz->dev->capacity, data); +} + +static struct target_type dmz_type = { + .name = "zoned", + .version = {1, 0, 0}, + .features = DM_TARGET_SINGLETON | DM_TARGET_ZONED_HM, + .module = THIS_MODULE, + .ctr = dmz_ctr, + .dtr = dmz_dtr, + .map = dmz_map, + .end_io = dmz_end_io, + .io_hints = dmz_io_hints, + .prepare_ioctl = dmz_prepare_ioctl, + .postsuspend = dmz_suspend, + .resume = dmz_resume, + .iterate_devices = dmz_iterate_devices, +}; + +static int __init dmz_init(void) +{ + return dm_register_target(&dmz_type); +} + +static void __exit dmz_exit(void) +{ + dm_unregister_target(&dmz_type); +} + +module_init(dmz_init); +module_exit(dmz_exit); + +MODULE_DESCRIPTION(DM_NAME " target for zoned block devices"); +MODULE_AUTHOR("Damien Le Moal "); +MODULE_LICENSE("GPL"); -- cgit