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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2017 Western Digital Corporation or its affiliates.4 *5 * This file is released under the GPL.6 */7 8#include "dm-zoned.h"9 10#include <linux/module.h>11 12#define DM_MSG_PREFIX "zoned reclaim"13 14struct dmz_reclaim {15 struct dmz_metadata *metadata;16 17 struct delayed_work work;18 struct workqueue_struct *wq;19 20 struct dm_kcopyd_client *kc;21 struct dm_kcopyd_throttle kc_throttle;22 int kc_err;23 24 int dev_idx;25 26 unsigned long flags;27 28 /* Last target access time */29 unsigned long atime;30};31 32/*33 * Reclaim state flags.34 */35enum {36 DMZ_RECLAIM_KCOPY,37};38 39/*40 * Number of seconds of target BIO inactivity to consider the target idle.41 */42#define DMZ_IDLE_PERIOD (10UL * HZ)43 44/*45 * Percentage of unmapped (free) random zones below which reclaim starts46 * even if the target is busy.47 */48#define DMZ_RECLAIM_LOW_UNMAP_ZONES 3049 50/*51 * Percentage of unmapped (free) random zones above which reclaim will52 * stop if the target is busy.53 */54#define DMZ_RECLAIM_HIGH_UNMAP_ZONES 5055 56/*57 * Align a sequential zone write pointer to chunk_block.58 */59static int dmz_reclaim_align_wp(struct dmz_reclaim *zrc, struct dm_zone *zone,60 sector_t block)61{62 struct dmz_metadata *zmd = zrc->metadata;63 struct dmz_dev *dev = zone->dev;64 sector_t wp_block = zone->wp_block;65 unsigned int nr_blocks;66 int ret;67 68 if (wp_block == block)69 return 0;70 71 if (wp_block > block)72 return -EIO;73 74 /*75 * Zeroout the space between the write76 * pointer and the requested position.77 */78 nr_blocks = block - wp_block;79 ret = blkdev_issue_zeroout(dev->bdev,80 dmz_start_sect(zmd, zone) + dmz_blk2sect(wp_block),81 dmz_blk2sect(nr_blocks), GFP_NOIO, 0);82 if (ret) {83 dmz_dev_err(dev,84 "Align zone %u wp %llu to %llu (wp+%u) blocks failed %d",85 zone->id, (unsigned long long)wp_block,86 (unsigned long long)block, nr_blocks, ret);87 dmz_check_bdev(dev);88 return ret;89 }90 91 zone->wp_block = block;92 93 return 0;94}95 96/*97 * dm_kcopyd_copy end notification.98 */99static void dmz_reclaim_kcopy_end(int read_err, unsigned long write_err,100 void *context)101{102 struct dmz_reclaim *zrc = context;103 104 if (read_err || write_err)105 zrc->kc_err = -EIO;106 else107 zrc->kc_err = 0;108 109 clear_bit_unlock(DMZ_RECLAIM_KCOPY, &zrc->flags);110 smp_mb__after_atomic();111 wake_up_bit(&zrc->flags, DMZ_RECLAIM_KCOPY);112}113 114/*115 * Copy valid blocks of src_zone into dst_zone.116 */117static int dmz_reclaim_copy(struct dmz_reclaim *zrc,118 struct dm_zone *src_zone, struct dm_zone *dst_zone)119{120 struct dmz_metadata *zmd = zrc->metadata;121 struct dm_io_region src, dst;122 sector_t block = 0, end_block;123 sector_t nr_blocks;124 sector_t src_zone_block;125 sector_t dst_zone_block;126 unsigned long flags = 0;127 int ret;128 129 if (dmz_is_seq(src_zone))130 end_block = src_zone->wp_block;131 else132 end_block = dmz_zone_nr_blocks(zmd);133 src_zone_block = dmz_start_block(zmd, src_zone);134 dst_zone_block = dmz_start_block(zmd, dst_zone);135 136 if (dmz_is_seq(dst_zone))137 flags |= BIT(DM_KCOPYD_WRITE_SEQ);138 139 while (block < end_block) {140 if (src_zone->dev->flags & DMZ_BDEV_DYING)141 return -EIO;142 if (dst_zone->dev->flags & DMZ_BDEV_DYING)143 return -EIO;144 145 if (dmz_reclaim_should_terminate(src_zone))146 return -EINTR;147 148 /* Get a valid region from the source zone */149 ret = dmz_first_valid_block(zmd, src_zone, &block);150 if (ret <= 0)151 return ret;152 nr_blocks = ret;153 154 /*155 * If we are writing in a sequential zone, we must make sure156 * that writes are sequential. So Zeroout any eventual hole157 * between writes.158 */159 if (dmz_is_seq(dst_zone)) {160 ret = dmz_reclaim_align_wp(zrc, dst_zone, block);161 if (ret)162 return ret;163 }164 165 src.bdev = src_zone->dev->bdev;166 src.sector = dmz_blk2sect(src_zone_block + block);167 src.count = dmz_blk2sect(nr_blocks);168 169 dst.bdev = dst_zone->dev->bdev;170 dst.sector = dmz_blk2sect(dst_zone_block + block);171 dst.count = src.count;172 173 /* Copy the valid region */174 set_bit(DMZ_RECLAIM_KCOPY, &zrc->flags);175 dm_kcopyd_copy(zrc->kc, &src, 1, &dst, flags,176 dmz_reclaim_kcopy_end, zrc);177 178 /* Wait for copy to complete */179 wait_on_bit_io(&zrc->flags, DMZ_RECLAIM_KCOPY,180 TASK_UNINTERRUPTIBLE);181 if (zrc->kc_err)182 return zrc->kc_err;183 184 block += nr_blocks;185 if (dmz_is_seq(dst_zone))186 dst_zone->wp_block = block;187 }188 189 return 0;190}191 192/*193 * Move valid blocks of dzone buffer zone into dzone (after its write pointer)194 * and free the buffer zone.195 */196static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone)197{198 struct dm_zone *bzone = dzone->bzone;199 sector_t chunk_block = dzone->wp_block;200 struct dmz_metadata *zmd = zrc->metadata;201 int ret;202 203 DMDEBUG("(%s/%u): Chunk %u, move buf zone %u (weight %u) to data zone %u (weight %u)",204 dmz_metadata_label(zmd), zrc->dev_idx,205 dzone->chunk, bzone->id, dmz_weight(bzone),206 dzone->id, dmz_weight(dzone));207 208 /* Flush data zone into the buffer zone */209 ret = dmz_reclaim_copy(zrc, bzone, dzone);210 if (ret < 0)211 return ret;212 213 dmz_lock_flush(zmd);214 215 /* Validate copied blocks */216 ret = dmz_merge_valid_blocks(zmd, bzone, dzone, chunk_block);217 if (ret == 0) {218 /* Free the buffer zone */219 dmz_invalidate_blocks(zmd, bzone, 0, dmz_zone_nr_blocks(zmd));220 dmz_lock_map(zmd);221 dmz_unmap_zone(zmd, bzone);222 dmz_unlock_zone_reclaim(dzone);223 dmz_free_zone(zmd, bzone);224 dmz_unlock_map(zmd);225 }226 227 dmz_unlock_flush(zmd);228 229 return ret;230}231 232/*233 * Merge valid blocks of dzone into its buffer zone and free dzone.234 */235static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)236{237 unsigned int chunk = dzone->chunk;238 struct dm_zone *bzone = dzone->bzone;239 struct dmz_metadata *zmd = zrc->metadata;240 int ret = 0;241 242 DMDEBUG("(%s/%u): Chunk %u, move data zone %u (weight %u) to buf zone %u (weight %u)",243 dmz_metadata_label(zmd), zrc->dev_idx,244 chunk, dzone->id, dmz_weight(dzone),245 bzone->id, dmz_weight(bzone));246 247 /* Flush data zone into the buffer zone */248 ret = dmz_reclaim_copy(zrc, dzone, bzone);249 if (ret < 0)250 return ret;251 252 dmz_lock_flush(zmd);253 254 /* Validate copied blocks */255 ret = dmz_merge_valid_blocks(zmd, dzone, bzone, 0);256 if (ret == 0) {257 /*258 * Free the data zone and remap the chunk to259 * the buffer zone.260 */261 dmz_invalidate_blocks(zmd, dzone, 0, dmz_zone_nr_blocks(zmd));262 dmz_lock_map(zmd);263 dmz_unmap_zone(zmd, bzone);264 dmz_unmap_zone(zmd, dzone);265 dmz_unlock_zone_reclaim(dzone);266 dmz_free_zone(zmd, dzone);267 dmz_map_zone(zmd, bzone, chunk);268 dmz_unlock_map(zmd);269 }270 271 dmz_unlock_flush(zmd);272 273 return ret;274}275 276/*277 * Move valid blocks of the random data zone dzone into a free sequential zone.278 * Once blocks are moved, remap the zone chunk to the sequential zone.279 */280static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)281{282 unsigned int chunk = dzone->chunk;283 struct dm_zone *szone = NULL;284 struct dmz_metadata *zmd = zrc->metadata;285 int ret;286 int alloc_flags = DMZ_ALLOC_SEQ;287 288 /* Get a free random or sequential zone */289 dmz_lock_map(zmd);290again:291 szone = dmz_alloc_zone(zmd, zrc->dev_idx,292 alloc_flags | DMZ_ALLOC_RECLAIM);293 if (!szone && alloc_flags == DMZ_ALLOC_SEQ && dmz_nr_cache_zones(zmd)) {294 alloc_flags = DMZ_ALLOC_RND;295 goto again;296 }297 dmz_unlock_map(zmd);298 if (!szone)299 return -ENOSPC;300 301 DMDEBUG("(%s/%u): Chunk %u, move %s zone %u (weight %u) to %s zone %u",302 dmz_metadata_label(zmd), zrc->dev_idx, chunk,303 dmz_is_cache(dzone) ? "cache" : "rnd",304 dzone->id, dmz_weight(dzone),305 dmz_is_rnd(szone) ? "rnd" : "seq", szone->id);306 307 /* Flush the random data zone into the sequential zone */308 ret = dmz_reclaim_copy(zrc, dzone, szone);309 310 dmz_lock_flush(zmd);311 312 if (ret == 0) {313 /* Validate copied blocks */314 ret = dmz_copy_valid_blocks(zmd, dzone, szone);315 }316 if (ret) {317 /* Free the sequential zone */318 dmz_lock_map(zmd);319 dmz_free_zone(zmd, szone);320 dmz_unlock_map(zmd);321 } else {322 /* Free the data zone and remap the chunk */323 dmz_invalidate_blocks(zmd, dzone, 0, dmz_zone_nr_blocks(zmd));324 dmz_lock_map(zmd);325 dmz_unmap_zone(zmd, dzone);326 dmz_unlock_zone_reclaim(dzone);327 dmz_free_zone(zmd, dzone);328 dmz_map_zone(zmd, szone, chunk);329 dmz_unlock_map(zmd);330 }331 332 dmz_unlock_flush(zmd);333 334 return ret;335}336 337/*338 * Reclaim an empty zone.339 */340static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone)341{342 struct dmz_metadata *zmd = zrc->metadata;343 344 dmz_lock_flush(zmd);345 dmz_lock_map(zmd);346 dmz_unmap_zone(zmd, dzone);347 dmz_unlock_zone_reclaim(dzone);348 dmz_free_zone(zmd, dzone);349 dmz_unlock_map(zmd);350 dmz_unlock_flush(zmd);351}352 353/*354 * Test if the target device is idle.355 */356static inline int dmz_target_idle(struct dmz_reclaim *zrc)357{358 return time_is_before_jiffies(zrc->atime + DMZ_IDLE_PERIOD);359}360 361/*362 * Find a candidate zone for reclaim and process it.363 */364static int dmz_do_reclaim(struct dmz_reclaim *zrc)365{366 struct dmz_metadata *zmd = zrc->metadata;367 struct dm_zone *dzone;368 struct dm_zone *rzone;369 unsigned long start;370 int ret;371 372 /* Get a data zone */373 dzone = dmz_get_zone_for_reclaim(zmd, zrc->dev_idx,374 dmz_target_idle(zrc));375 if (!dzone) {376 DMDEBUG("(%s/%u): No zone found to reclaim",377 dmz_metadata_label(zmd), zrc->dev_idx);378 return -EBUSY;379 }380 rzone = dzone;381 382 start = jiffies;383 if (dmz_is_cache(dzone) || dmz_is_rnd(dzone)) {384 if (!dmz_weight(dzone)) {385 /* Empty zone */386 dmz_reclaim_empty(zrc, dzone);387 ret = 0;388 } else {389 /*390 * Reclaim the random data zone by moving its391 * valid data blocks to a free sequential zone.392 */393 ret = dmz_reclaim_rnd_data(zrc, dzone);394 }395 } else {396 struct dm_zone *bzone = dzone->bzone;397 sector_t chunk_block = 0;398 399 ret = dmz_first_valid_block(zmd, bzone, &chunk_block);400 if (ret < 0)401 goto out;402 403 if (ret == 0 || chunk_block >= dzone->wp_block) {404 /*405 * The buffer zone is empty or its valid blocks are406 * after the data zone write pointer.407 */408 ret = dmz_reclaim_buf(zrc, dzone);409 rzone = bzone;410 } else {411 /*412 * Reclaim the data zone by merging it into the413 * buffer zone so that the buffer zone itself can414 * be later reclaimed.415 */416 ret = dmz_reclaim_seq_data(zrc, dzone);417 }418 }419out:420 if (ret) {421 if (ret == -EINTR)422 DMDEBUG("(%s/%u): reclaim zone %u interrupted",423 dmz_metadata_label(zmd), zrc->dev_idx,424 rzone->id);425 else426 DMDEBUG("(%s/%u): Failed to reclaim zone %u, err %d",427 dmz_metadata_label(zmd), zrc->dev_idx,428 rzone->id, ret);429 dmz_unlock_zone_reclaim(dzone);430 return ret;431 }432 433 ret = dmz_flush_metadata(zrc->metadata);434 if (ret) {435 DMDEBUG("(%s/%u): Metadata flush for zone %u failed, err %d",436 dmz_metadata_label(zmd), zrc->dev_idx, rzone->id, ret);437 return ret;438 }439 440 DMDEBUG("(%s/%u): Reclaimed zone %u in %u ms",441 dmz_metadata_label(zmd), zrc->dev_idx,442 rzone->id, jiffies_to_msecs(jiffies - start));443 return 0;444}445 446static unsigned int dmz_reclaim_percentage(struct dmz_reclaim *zrc)447{448 struct dmz_metadata *zmd = zrc->metadata;449 unsigned int nr_cache = dmz_nr_cache_zones(zmd);450 unsigned int nr_unmap, nr_zones;451 452 if (nr_cache) {453 nr_zones = nr_cache;454 nr_unmap = dmz_nr_unmap_cache_zones(zmd);455 } else {456 nr_zones = dmz_nr_rnd_zones(zmd, zrc->dev_idx);457 nr_unmap = dmz_nr_unmap_rnd_zones(zmd, zrc->dev_idx);458 }459 if (nr_unmap <= 1)460 return 0;461 return nr_unmap * 100 / nr_zones;462}463 464/*465 * Test if reclaim is necessary.466 */467static bool dmz_should_reclaim(struct dmz_reclaim *zrc, unsigned int p_unmap)468{469 unsigned int nr_reclaim;470 471 nr_reclaim = dmz_nr_rnd_zones(zrc->metadata, zrc->dev_idx);472 473 if (dmz_nr_cache_zones(zrc->metadata)) {474 /*475 * The first device in a multi-device476 * setup only contains cache zones, so477 * never start reclaim there.478 */479 if (zrc->dev_idx == 0)480 return false;481 nr_reclaim += dmz_nr_cache_zones(zrc->metadata);482 }483 484 /* Reclaim when idle */485 if (dmz_target_idle(zrc) && nr_reclaim)486 return true;487 488 /* If there are still plenty of cache zones, do not reclaim */489 if (p_unmap >= DMZ_RECLAIM_HIGH_UNMAP_ZONES)490 return false;491 492 /*493 * If the percentage of unmapped cache zones is low,494 * reclaim even if the target is busy.495 */496 return p_unmap <= DMZ_RECLAIM_LOW_UNMAP_ZONES;497}498 499/*500 * Reclaim work function.501 */502static void dmz_reclaim_work(struct work_struct *work)503{504 struct dmz_reclaim *zrc = container_of(work, struct dmz_reclaim, work.work);505 struct dmz_metadata *zmd = zrc->metadata;506 unsigned int p_unmap;507 int ret;508 509 if (dmz_dev_is_dying(zmd))510 return;511 512 p_unmap = dmz_reclaim_percentage(zrc);513 if (!dmz_should_reclaim(zrc, p_unmap)) {514 mod_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);515 return;516 }517 518 /*519 * We need to start reclaiming random zones: set up zone copy520 * throttling to either go fast if we are very low on random zones521 * and slower if there are still some free random zones to avoid522 * as much as possible to negatively impact the user workload.523 */524 if (dmz_target_idle(zrc) || p_unmap < DMZ_RECLAIM_LOW_UNMAP_ZONES / 2) {525 /* Idle or very low percentage: go fast */526 zrc->kc_throttle.throttle = 100;527 } else {528 /* Busy but we still have some random zone: throttle */529 zrc->kc_throttle.throttle = min(75U, 100U - p_unmap / 2);530 }531 532 DMDEBUG("(%s/%u): Reclaim (%u): %s, %u%% free zones (%u/%u cache %u/%u random)",533 dmz_metadata_label(zmd), zrc->dev_idx,534 zrc->kc_throttle.throttle,535 (dmz_target_idle(zrc) ? "Idle" : "Busy"),536 p_unmap, dmz_nr_unmap_cache_zones(zmd),537 dmz_nr_cache_zones(zmd),538 dmz_nr_unmap_rnd_zones(zmd, zrc->dev_idx),539 dmz_nr_rnd_zones(zmd, zrc->dev_idx));540 541 ret = dmz_do_reclaim(zrc);542 if (ret && ret != -EINTR) {543 if (!dmz_check_dev(zmd))544 return;545 }546 547 dmz_schedule_reclaim(zrc);548}549 550/*551 * Initialize reclaim.552 */553int dmz_ctr_reclaim(struct dmz_metadata *zmd,554 struct dmz_reclaim **reclaim, int idx)555{556 struct dmz_reclaim *zrc;557 int ret;558 559 zrc = kzalloc(sizeof(struct dmz_reclaim), GFP_KERNEL);560 if (!zrc)561 return -ENOMEM;562 563 zrc->metadata = zmd;564 zrc->atime = jiffies;565 zrc->dev_idx = idx;566 567 /* Reclaim kcopyd client */568 zrc->kc = dm_kcopyd_client_create(&zrc->kc_throttle);569 if (IS_ERR(zrc->kc)) {570 ret = PTR_ERR(zrc->kc);571 zrc->kc = NULL;572 goto err;573 }574 575 /* Reclaim work */576 INIT_DELAYED_WORK(&zrc->work, dmz_reclaim_work);577 zrc->wq = alloc_ordered_workqueue("dmz_rwq_%s_%d", WQ_MEM_RECLAIM,578 dmz_metadata_label(zmd), idx);579 if (!zrc->wq) {580 ret = -ENOMEM;581 goto err;582 }583 584 *reclaim = zrc;585 queue_delayed_work(zrc->wq, &zrc->work, 0);586 587 return 0;588err:589 if (zrc->kc)590 dm_kcopyd_client_destroy(zrc->kc);591 kfree(zrc);592 593 return ret;594}595 596/*597 * Terminate reclaim.598 */599void dmz_dtr_reclaim(struct dmz_reclaim *zrc)600{601 cancel_delayed_work_sync(&zrc->work);602 destroy_workqueue(zrc->wq);603 dm_kcopyd_client_destroy(zrc->kc);604 kfree(zrc);605}606 607/*608 * Suspend reclaim.609 */610void dmz_suspend_reclaim(struct dmz_reclaim *zrc)611{612 cancel_delayed_work_sync(&zrc->work);613}614 615/*616 * Resume reclaim.617 */618void dmz_resume_reclaim(struct dmz_reclaim *zrc)619{620 queue_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);621}622 623/*624 * BIO accounting.625 */626void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc)627{628 zrc->atime = jiffies;629}630 631/*632 * Start reclaim if necessary.633 */634void dmz_schedule_reclaim(struct dmz_reclaim *zrc)635{636 unsigned int p_unmap = dmz_reclaim_percentage(zrc);637 638 if (dmz_should_reclaim(zrc, p_unmap))639 mod_delayed_work(zrc->wq, &zrc->work, 0);640}641