| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2017 Western Digital Corporation or its affiliates. |
| * |
| * This file is released under the GPL. |
| */ |
| |
| #include "dm-zoned.h" |
| |
| #include <linux/module.h> |
| |
| #define DM_MSG_PREFIX "zoned reclaim" |
| |
| struct dmz_reclaim { |
| struct dmz_metadata *metadata; |
| struct dmz_dev *dev; |
| |
| struct delayed_work work; |
| struct workqueue_struct *wq; |
| |
| struct dm_kcopyd_client *kc; |
| struct dm_kcopyd_throttle kc_throttle; |
| int kc_err; |
| |
| unsigned long flags; |
| |
| /* Last target access time */ |
| unsigned long atime; |
| }; |
| |
| /* |
| * Reclaim state flags. |
| */ |
| enum { |
| DMZ_RECLAIM_KCOPY, |
| }; |
| |
| /* |
| * Number of seconds of target BIO inactivity to consider the target idle. |
| */ |
| #define DMZ_IDLE_PERIOD (10UL * HZ) |
| |
| /* |
| * Percentage of unmapped (free) random zones below which reclaim starts |
| * even if the target is busy. |
| */ |
| #define DMZ_RECLAIM_LOW_UNMAP_RND 30 |
| |
| /* |
| * Percentage of unmapped (free) random zones above which reclaim will |
| * stop if the target is busy. |
| */ |
| #define DMZ_RECLAIM_HIGH_UNMAP_RND 50 |
| |
| /* |
| * Align a sequential zone write pointer to chunk_block. |
| */ |
| static int dmz_reclaim_align_wp(struct dmz_reclaim *zrc, struct dm_zone *zone, |
| sector_t block) |
| { |
| struct dmz_metadata *zmd = zrc->metadata; |
| sector_t wp_block = zone->wp_block; |
| unsigned int nr_blocks; |
| int ret; |
| |
| if (wp_block == block) |
| return 0; |
| |
| if (wp_block > block) |
| return -EIO; |
| |
| /* |
| * Zeroout the space between the write |
| * pointer and the requested position. |
| */ |
| nr_blocks = block - wp_block; |
| ret = blkdev_issue_zeroout(zrc->dev->bdev, |
| dmz_start_sect(zmd, zone) + dmz_blk2sect(wp_block), |
| dmz_blk2sect(nr_blocks), GFP_NOIO, 0); |
| if (ret) { |
| dmz_dev_err(zrc->dev, |
| "Align zone %u wp %llu to %llu (wp+%u) blocks failed %d", |
| dmz_id(zmd, zone), (unsigned long long)wp_block, |
| (unsigned long long)block, nr_blocks, ret); |
| return ret; |
| } |
| |
| zone->wp_block = block; |
| |
| return 0; |
| } |
| |
| /* |
| * dm_kcopyd_copy end notification. |
| */ |
| static void dmz_reclaim_kcopy_end(int read_err, unsigned long write_err, |
| void *context) |
| { |
| struct dmz_reclaim *zrc = context; |
| |
| if (read_err || write_err) |
| zrc->kc_err = -EIO; |
| else |
| zrc->kc_err = 0; |
| |
| clear_bit_unlock(DMZ_RECLAIM_KCOPY, &zrc->flags); |
| smp_mb__after_atomic(); |
| wake_up_bit(&zrc->flags, DMZ_RECLAIM_KCOPY); |
| } |
| |
| /* |
| * Copy valid blocks of src_zone into dst_zone. |
| */ |
| static int dmz_reclaim_copy(struct dmz_reclaim *zrc, |
| struct dm_zone *src_zone, struct dm_zone *dst_zone) |
| { |
| struct dmz_metadata *zmd = zrc->metadata; |
| struct dmz_dev *dev = zrc->dev; |
| struct dm_io_region src, dst; |
| sector_t block = 0, end_block; |
| sector_t nr_blocks; |
| sector_t src_zone_block; |
| sector_t dst_zone_block; |
| unsigned long flags = 0; |
| int ret; |
| |
| if (dmz_is_seq(src_zone)) |
| end_block = src_zone->wp_block; |
| else |
| end_block = dev->zone_nr_blocks; |
| src_zone_block = dmz_start_block(zmd, src_zone); |
| dst_zone_block = dmz_start_block(zmd, dst_zone); |
| |
| if (dmz_is_seq(dst_zone)) |
| set_bit(DM_KCOPYD_WRITE_SEQ, &flags); |
| |
| while (block < end_block) { |
| if (dev->flags & DMZ_BDEV_DYING) |
| return -EIO; |
| |
| /* Get a valid region from the source zone */ |
| ret = dmz_first_valid_block(zmd, src_zone, &block); |
| if (ret <= 0) |
| return ret; |
| nr_blocks = ret; |
| |
| /* |
| * If we are writing in a sequential zone, we must make sure |
| * that writes are sequential. So Zeroout any eventual hole |
| * between writes. |
| */ |
| if (dmz_is_seq(dst_zone)) { |
| ret = dmz_reclaim_align_wp(zrc, dst_zone, block); |
| if (ret) |
| return ret; |
| } |
| |
| src.bdev = dev->bdev; |
| src.sector = dmz_blk2sect(src_zone_block + block); |
| src.count = dmz_blk2sect(nr_blocks); |
| |
| dst.bdev = dev->bdev; |
| dst.sector = dmz_blk2sect(dst_zone_block + block); |
| dst.count = src.count; |
| |
| /* Copy the valid region */ |
| set_bit(DMZ_RECLAIM_KCOPY, &zrc->flags); |
| dm_kcopyd_copy(zrc->kc, &src, 1, &dst, flags, |
| dmz_reclaim_kcopy_end, zrc); |
| |
| /* Wait for copy to complete */ |
| wait_on_bit_io(&zrc->flags, DMZ_RECLAIM_KCOPY, |
| TASK_UNINTERRUPTIBLE); |
| if (zrc->kc_err) |
| return zrc->kc_err; |
| |
| block += nr_blocks; |
| if (dmz_is_seq(dst_zone)) |
| dst_zone->wp_block = block; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Move valid blocks of dzone buffer zone into dzone (after its write pointer) |
| * and free the buffer zone. |
| */ |
| static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone) |
| { |
| struct dm_zone *bzone = dzone->bzone; |
| sector_t chunk_block = dzone->wp_block; |
| struct dmz_metadata *zmd = zrc->metadata; |
| int ret; |
| |
| dmz_dev_debug(zrc->dev, |
| "Chunk %u, move buf zone %u (weight %u) to data zone %u (weight %u)", |
| dzone->chunk, dmz_id(zmd, bzone), dmz_weight(bzone), |
| dmz_id(zmd, dzone), dmz_weight(dzone)); |
| |
| /* Flush data zone into the buffer zone */ |
| ret = dmz_reclaim_copy(zrc, bzone, dzone); |
| if (ret < 0) |
| return ret; |
| |
| dmz_lock_flush(zmd); |
| |
| /* Validate copied blocks */ |
| ret = dmz_merge_valid_blocks(zmd, bzone, dzone, chunk_block); |
| if (ret == 0) { |
| /* Free the buffer zone */ |
| dmz_invalidate_blocks(zmd, bzone, 0, zrc->dev->zone_nr_blocks); |
| dmz_lock_map(zmd); |
| dmz_unmap_zone(zmd, bzone); |
| dmz_unlock_zone_reclaim(dzone); |
| dmz_free_zone(zmd, bzone); |
| dmz_unlock_map(zmd); |
| } |
| |
| dmz_unlock_flush(zmd); |
| |
| return ret; |
| } |
| |
| /* |
| * Merge valid blocks of dzone into its buffer zone and free dzone. |
| */ |
| static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone) |
| { |
| unsigned int chunk = dzone->chunk; |
| struct dm_zone *bzone = dzone->bzone; |
| struct dmz_metadata *zmd = zrc->metadata; |
| int ret = 0; |
| |
| dmz_dev_debug(zrc->dev, |
| "Chunk %u, move data zone %u (weight %u) to buf zone %u (weight %u)", |
| chunk, dmz_id(zmd, dzone), dmz_weight(dzone), |
| dmz_id(zmd, bzone), dmz_weight(bzone)); |
| |
| /* Flush data zone into the buffer zone */ |
| ret = dmz_reclaim_copy(zrc, dzone, bzone); |
| if (ret < 0) |
| return ret; |
| |
| dmz_lock_flush(zmd); |
| |
| /* Validate copied blocks */ |
| ret = dmz_merge_valid_blocks(zmd, dzone, bzone, 0); |
| if (ret == 0) { |
| /* |
| * Free the data zone and remap the chunk to |
| * the buffer zone. |
| */ |
| dmz_invalidate_blocks(zmd, dzone, 0, zrc->dev->zone_nr_blocks); |
| dmz_lock_map(zmd); |
| dmz_unmap_zone(zmd, bzone); |
| dmz_unmap_zone(zmd, dzone); |
| dmz_unlock_zone_reclaim(dzone); |
| dmz_free_zone(zmd, dzone); |
| dmz_map_zone(zmd, bzone, chunk); |
| dmz_unlock_map(zmd); |
| } |
| |
| dmz_unlock_flush(zmd); |
| |
| return ret; |
| } |
| |
| /* |
| * Move valid blocks of the random data zone dzone into a free sequential zone. |
| * Once blocks are moved, remap the zone chunk to the sequential zone. |
| */ |
| static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone) |
| { |
| unsigned int chunk = dzone->chunk; |
| struct dm_zone *szone = NULL; |
| struct dmz_metadata *zmd = zrc->metadata; |
| int ret; |
| |
| /* Get a free sequential zone */ |
| dmz_lock_map(zmd); |
| szone = dmz_alloc_zone(zmd, DMZ_ALLOC_RECLAIM); |
| dmz_unlock_map(zmd); |
| if (!szone) |
| return -ENOSPC; |
| |
| dmz_dev_debug(zrc->dev, |
| "Chunk %u, move rnd zone %u (weight %u) to seq zone %u", |
| chunk, dmz_id(zmd, dzone), dmz_weight(dzone), |
| dmz_id(zmd, szone)); |
| |
| /* Flush the random data zone into the sequential zone */ |
| ret = dmz_reclaim_copy(zrc, dzone, szone); |
| |
| dmz_lock_flush(zmd); |
| |
| if (ret == 0) { |
| /* Validate copied blocks */ |
| ret = dmz_copy_valid_blocks(zmd, dzone, szone); |
| } |
| if (ret) { |
| /* Free the sequential zone */ |
| dmz_lock_map(zmd); |
| dmz_free_zone(zmd, szone); |
| dmz_unlock_map(zmd); |
| } else { |
| /* Free the data zone and remap the chunk */ |
| dmz_invalidate_blocks(zmd, dzone, 0, zrc->dev->zone_nr_blocks); |
| dmz_lock_map(zmd); |
| dmz_unmap_zone(zmd, dzone); |
| dmz_unlock_zone_reclaim(dzone); |
| dmz_free_zone(zmd, dzone); |
| dmz_map_zone(zmd, szone, chunk); |
| dmz_unlock_map(zmd); |
| } |
| |
| dmz_unlock_flush(zmd); |
| |
| return ret; |
| } |
| |
| /* |
| * Reclaim an empty zone. |
| */ |
| static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone) |
| { |
| struct dmz_metadata *zmd = zrc->metadata; |
| |
| dmz_lock_flush(zmd); |
| dmz_lock_map(zmd); |
| dmz_unmap_zone(zmd, dzone); |
| dmz_unlock_zone_reclaim(dzone); |
| dmz_free_zone(zmd, dzone); |
| dmz_unlock_map(zmd); |
| dmz_unlock_flush(zmd); |
| } |
| |
| /* |
| * Find a candidate zone for reclaim and process it. |
| */ |
| static int dmz_do_reclaim(struct dmz_reclaim *zrc) |
| { |
| struct dmz_metadata *zmd = zrc->metadata; |
| struct dm_zone *dzone; |
| struct dm_zone *rzone; |
| unsigned long start; |
| int ret; |
| |
| /* Get a data zone */ |
| dzone = dmz_get_zone_for_reclaim(zmd); |
| if (IS_ERR(dzone)) |
| return PTR_ERR(dzone); |
| |
| start = jiffies; |
| |
| if (dmz_is_rnd(dzone)) { |
| if (!dmz_weight(dzone)) { |
| /* Empty zone */ |
| dmz_reclaim_empty(zrc, dzone); |
| ret = 0; |
| } else { |
| /* |
| * Reclaim the random data zone by moving its |
| * valid data blocks to a free sequential zone. |
| */ |
| ret = dmz_reclaim_rnd_data(zrc, dzone); |
| } |
| rzone = dzone; |
| |
| } else { |
| struct dm_zone *bzone = dzone->bzone; |
| sector_t chunk_block = 0; |
| |
| ret = dmz_first_valid_block(zmd, bzone, &chunk_block); |
| if (ret < 0) |
| goto out; |
| |
| if (ret == 0 || chunk_block >= dzone->wp_block) { |
| /* |
| * The buffer zone is empty or its valid blocks are |
| * after the data zone write pointer. |
| */ |
| ret = dmz_reclaim_buf(zrc, dzone); |
| rzone = bzone; |
| } else { |
| /* |
| * Reclaim the data zone by merging it into the |
| * buffer zone so that the buffer zone itself can |
| * be later reclaimed. |
| */ |
| ret = dmz_reclaim_seq_data(zrc, dzone); |
| rzone = dzone; |
| } |
| } |
| out: |
| if (ret) { |
| dmz_unlock_zone_reclaim(dzone); |
| return ret; |
| } |
| |
| ret = dmz_flush_metadata(zrc->metadata); |
| if (ret) { |
| dmz_dev_debug(zrc->dev, |
| "Metadata flush for zone %u failed, err %d\n", |
| dmz_id(zmd, rzone), ret); |
| return ret; |
| } |
| |
| dmz_dev_debug(zrc->dev, "Reclaimed zone %u in %u ms", |
| dmz_id(zmd, rzone), jiffies_to_msecs(jiffies - start)); |
| return 0; |
| } |
| |
| /* |
| * Test if the target device is idle. |
| */ |
| static inline int dmz_target_idle(struct dmz_reclaim *zrc) |
| { |
| return time_is_before_jiffies(zrc->atime + DMZ_IDLE_PERIOD); |
| } |
| |
| /* |
| * Test if reclaim is necessary. |
| */ |
| static bool dmz_should_reclaim(struct dmz_reclaim *zrc) |
| { |
| struct dmz_metadata *zmd = zrc->metadata; |
| unsigned int nr_rnd = dmz_nr_rnd_zones(zmd); |
| unsigned int nr_unmap_rnd = dmz_nr_unmap_rnd_zones(zmd); |
| unsigned int p_unmap_rnd = nr_unmap_rnd * 100 / nr_rnd; |
| |
| /* Reclaim when idle */ |
| if (dmz_target_idle(zrc) && nr_unmap_rnd < nr_rnd) |
| return true; |
| |
| /* If there are still plenty of random zones, do not reclaim */ |
| if (p_unmap_rnd >= DMZ_RECLAIM_HIGH_UNMAP_RND) |
| return false; |
| |
| /* |
| * If the percentage of unmapped random zones is low, |
| * reclaim even if the target is busy. |
| */ |
| return p_unmap_rnd <= DMZ_RECLAIM_LOW_UNMAP_RND; |
| } |
| |
| /* |
| * Reclaim work function. |
| */ |
| static void dmz_reclaim_work(struct work_struct *work) |
| { |
| struct dmz_reclaim *zrc = container_of(work, struct dmz_reclaim, work.work); |
| struct dmz_metadata *zmd = zrc->metadata; |
| unsigned int nr_rnd, nr_unmap_rnd; |
| unsigned int p_unmap_rnd; |
| int ret; |
| |
| if (dmz_bdev_is_dying(zrc->dev)) |
| return; |
| |
| if (!dmz_should_reclaim(zrc)) { |
| mod_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD); |
| return; |
| } |
| |
| /* |
| * We need to start reclaiming random zones: set up zone copy |
| * throttling to either go fast if we are very low on random zones |
| * and slower if there are still some free random zones to avoid |
| * as much as possible to negatively impact the user workload. |
| */ |
| nr_rnd = dmz_nr_rnd_zones(zmd); |
| nr_unmap_rnd = dmz_nr_unmap_rnd_zones(zmd); |
| p_unmap_rnd = nr_unmap_rnd * 100 / nr_rnd; |
| if (dmz_target_idle(zrc) || p_unmap_rnd < DMZ_RECLAIM_LOW_UNMAP_RND / 2) { |
| /* Idle or very low percentage: go fast */ |
| zrc->kc_throttle.throttle = 100; |
| } else { |
| /* Busy but we still have some random zone: throttle */ |
| zrc->kc_throttle.throttle = min(75U, 100U - p_unmap_rnd / 2); |
| } |
| |
| dmz_dev_debug(zrc->dev, |
| "Reclaim (%u): %s, %u%% free rnd zones (%u/%u)", |
| zrc->kc_throttle.throttle, |
| (dmz_target_idle(zrc) ? "Idle" : "Busy"), |
| p_unmap_rnd, nr_unmap_rnd, nr_rnd); |
| |
| ret = dmz_do_reclaim(zrc); |
| if (ret) { |
| dmz_dev_debug(zrc->dev, "Reclaim error %d\n", ret); |
| if (ret == -EIO) |
| /* |
| * LLD might be performing some error handling sequence |
| * at the underlying device. To not interfere, do not |
| * attempt to schedule the next reclaim run immediately. |
| */ |
| return; |
| } |
| |
| dmz_schedule_reclaim(zrc); |
| } |
| |
| /* |
| * Initialize reclaim. |
| */ |
| int dmz_ctr_reclaim(struct dmz_dev *dev, struct dmz_metadata *zmd, |
| struct dmz_reclaim **reclaim) |
| { |
| struct dmz_reclaim *zrc; |
| int ret; |
| |
| zrc = kzalloc(sizeof(struct dmz_reclaim), GFP_KERNEL); |
| if (!zrc) |
| return -ENOMEM; |
| |
| zrc->dev = dev; |
| zrc->metadata = zmd; |
| zrc->atime = jiffies; |
| |
| /* Reclaim kcopyd client */ |
| zrc->kc = dm_kcopyd_client_create(&zrc->kc_throttle); |
| if (IS_ERR(zrc->kc)) { |
| ret = PTR_ERR(zrc->kc); |
| zrc->kc = NULL; |
| goto err; |
| } |
| |
| /* Reclaim work */ |
| INIT_DELAYED_WORK(&zrc->work, dmz_reclaim_work); |
| zrc->wq = alloc_ordered_workqueue("dmz_rwq_%s", WQ_MEM_RECLAIM, |
| dev->name); |
| if (!zrc->wq) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| *reclaim = zrc; |
| queue_delayed_work(zrc->wq, &zrc->work, 0); |
| |
| return 0; |
| err: |
| if (zrc->kc) |
| dm_kcopyd_client_destroy(zrc->kc); |
| kfree(zrc); |
| |
| return ret; |
| } |
| |
| /* |
| * Terminate reclaim. |
| */ |
| void dmz_dtr_reclaim(struct dmz_reclaim *zrc) |
| { |
| cancel_delayed_work_sync(&zrc->work); |
| destroy_workqueue(zrc->wq); |
| dm_kcopyd_client_destroy(zrc->kc); |
| kfree(zrc); |
| } |
| |
| /* |
| * Suspend reclaim. |
| */ |
| void dmz_suspend_reclaim(struct dmz_reclaim *zrc) |
| { |
| cancel_delayed_work_sync(&zrc->work); |
| } |
| |
| /* |
| * Resume reclaim. |
| */ |
| void dmz_resume_reclaim(struct dmz_reclaim *zrc) |
| { |
| queue_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD); |
| } |
| |
| /* |
| * BIO accounting. |
| */ |
| void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc) |
| { |
| zrc->atime = jiffies; |
| } |
| |
| /* |
| * Start reclaim if necessary. |
| */ |
| void dmz_schedule_reclaim(struct dmz_reclaim *zrc) |
| { |
| if (dmz_should_reclaim(zrc)) |
| mod_delayed_work(zrc->wq, &zrc->work, 0); |
| } |
| |