drivers/md/dm-zoned-target.c

   1 /*
   2  * Copyright (C) 2017 Western Digital Corporation or its affiliates.
   3  *
   4  * This file is released under the GPL.
   5  */
   6
   7 #include "dm-zoned.h"
   8
   9 #include <linux/module.h>
  10
  11 #define DM_MSG_PREFIX           "zoned"
  12
  13 #define DMZ_MIN_BIOS            8192
  14
  15 /*
  16  * Zone BIO context.
  17  */
  18 struct dmz_bioctx {
  19         struct dmz_target       *target;
  20         struct dm_zone          *zone;
  21         struct bio              *bio;
  22         atomic_t                ref;
  23         blk_status_t            status;
  24 };
  25
  26 /*
  27  * Chunk work descriptor.
  28  */
  29 struct dm_chunk_work {
  30         struct work_struct      work;
  31         atomic_t                refcount;
  32         struct dmz_target       *target;
  33         unsigned int            chunk;
  34         struct bio_list         bio_list;
  35 };
  36
  37 /*
  38  * Target descriptor.
  39  */
  40 struct dmz_target {
  41         struct dm_dev           *ddev;
  42
  43         unsigned long           flags;
  44
  45         /* Zoned block device information */
  46         struct dmz_dev          *dev;
  47
  48         /* For metadata handling */
  49         struct dmz_metadata     *metadata;
  50
  51         /* For reclaim */
  52         struct dmz_reclaim      *reclaim;
  53
  54         /* For chunk work */
  55         struct mutex            chunk_lock;
  56         struct radix_tree_root  chunk_rxtree;
  57         struct workqueue_struct *chunk_wq;
  58
  59         /* For cloned BIOs to zones */
  60         struct bio_set          *bio_set;
  61
  62         /* For flush */
  63         spinlock_t              flush_lock;
  64         struct bio_list         flush_list;
  65         struct delayed_work     flush_work;
  66         struct workqueue_struct *flush_wq;
  67 };
  68
  69 /*
  70  * Flush intervals (seconds).
  71  */
  72 #define DMZ_FLUSH_PERIOD        (10 * HZ)
  73
  74 /*
  75  * Target BIO completion.
  76  */
  77 static inline void dmz_bio_endio(struct bio *bio, blk_status_t status)
  78 {
  79         struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
  80
  81         if (bioctx->status == BLK_STS_OK && status != BLK_STS_OK)
  82                 bioctx->status = status;
  83         bio_endio(bio);
  84 }
  85
  86 /*
  87  * Partial clone read BIO completion callback. This terminates the
  88  * target BIO when there are no more references to its context.
  89  */
  90 static void dmz_read_bio_end_io(struct bio *bio)
  91 {
  92         struct dmz_bioctx *bioctx = bio->bi_private;
  93         blk_status_t status = bio->bi_status;
  94
  95         bio_put(bio);
  96         dmz_bio_endio(bioctx->bio, status);
  97 }
  98
  99 /*
 100  * Issue a BIO to a zone. The BIO may only partially process the
 101  * original target BIO.
 102  */
 103 static int dmz_submit_read_bio(struct dmz_target *dmz, struct dm_zone *zone,
 104                                struct bio *bio, sector_t chunk_block,
 105                                unsigned int nr_blocks)
 106 {
 107         struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
 108         sector_t sector;
 109         struct bio *clone;
 110
 111         /* BIO remap sector */
 112         sector = dmz_start_sect(dmz->metadata, zone) + dmz_blk2sect(chunk_block);
 113
 114         /* If the read is not partial, there is no need to clone the BIO */
 115         if (nr_blocks == dmz_bio_blocks(bio)) {
 116                 /* Setup and submit the BIO */
 117                 bio->bi_iter.bi_sector = sector;
 118                 atomic_inc(&bioctx->ref);
 119                 generic_make_request(bio);
 120                 return 0;
 121         }
 122
 123         /* Partial BIO: we need to clone the BIO */
 124         clone = bio_clone_fast(bio, GFP_NOIO, dmz->bio_set);
 125         if (!clone)
 126                 return -ENOMEM;
 127
 128         /* Setup the clone */
 129         clone->bi_iter.bi_sector = sector;
 130         clone->bi_iter.bi_size = dmz_blk2sect(nr_blocks) << SECTOR_SHIFT;
 131         clone->bi_end_io = dmz_read_bio_end_io;
 132         clone->bi_private = bioctx;
 133
 134         bio_advance(bio, clone->bi_iter.bi_size);
 135
 136         /* Submit the clone */
 137         atomic_inc(&bioctx->ref);
 138         generic_make_request(clone);
 139
 140         return 0;
 141 }
 142
 143 /*
 144  * Zero out pages of discarded blocks accessed by a read BIO.
 145  */
 146 static void dmz_handle_read_zero(struct dmz_target *dmz, struct bio *bio,
 147                                  sector_t chunk_block, unsigned int nr_blocks)
 148 {
 149         unsigned int size = nr_blocks << DMZ_BLOCK_SHIFT;
 150
 151         /* Clear nr_blocks */
 152         swap(bio->bi_iter.bi_size, size);
 153         zero_fill_bio(bio);
 154         swap(bio->bi_iter.bi_size, size);
 155
 156         bio_advance(bio, size);
 157 }
 158
 159 /*
 160  * Process a read BIO.
 161  */
 162 static int dmz_handle_read(struct dmz_target *dmz, struct dm_zone *zone,
 163                            struct bio *bio)
 164 {
 165         sector_t chunk_block = dmz_chunk_block(dmz->dev, dmz_bio_block(bio));
 166         unsigned int nr_blocks = dmz_bio_blocks(bio);
 167         sector_t end_block = chunk_block + nr_blocks;
 168         struct dm_zone *rzone, *bzone;
 169         int ret;
 170
 171         /* Read into unmapped chunks need only zeroing the BIO buffer */
 172         if (!zone) {
 173                 zero_fill_bio(bio);
 174                 return 0;
 175         }
 176
 177         dmz_dev_debug(dmz->dev, "READ chunk %llu -> %s zone %u, block %llu, %u blocks",
 178                       (unsigned long long)dmz_bio_chunk(dmz->dev, bio),
 179                       (dmz_is_rnd(zone) ? "RND" : "SEQ"),
 180                       dmz_id(dmz->metadata, zone),
 181                       (unsigned long long)chunk_block, nr_blocks);
 182
 183         /* Check block validity to determine the read location */
 184         bzone = zone->bzone;
 185         while (chunk_block < end_block) {
 186                 nr_blocks = 0;
 187                 if (dmz_is_rnd(zone) || chunk_block < zone->wp_block) {
 188                         /* Test block validity in the data zone */
 189                         ret = dmz_block_valid(dmz->metadata, zone, chunk_block);
 190                         if (ret < 0)
 191                                 return ret;
 192                         if (ret > 0) {
 193                                 /* Read data zone blocks */
 194                                 nr_blocks = ret;
 195                                 rzone = zone;
 196                         }
 197                 }
 198
 199                 /*
 200                  * No valid blocks found in the data zone.
 201                  * Check the buffer zone, if there is one.
 202                  */
 203                 if (!nr_blocks && bzone) {
 204                         ret = dmz_block_valid(dmz->metadata, bzone, chunk_block);
 205                         if (ret < 0)
 206                                 return ret;
 207                         if (ret > 0) {
 208                                 /* Read buffer zone blocks */
 209                                 nr_blocks = ret;
 210                                 rzone = bzone;
 211                         }
 212                 }
 213
 214                 if (nr_blocks) {
 215                         /* Valid blocks found: read them */
 216                         nr_blocks = min_t(unsigned int, nr_blocks, end_block - chunk_block);
 217                         ret = dmz_submit_read_bio(dmz, rzone, bio, chunk_block, nr_blocks);
 218                         if (ret)
 219                                 return ret;
 220                         chunk_block += nr_blocks;
 221                 } else {
 222                         /* No valid block: zeroout the current BIO block */
 223                         dmz_handle_read_zero(dmz, bio, chunk_block, 1);
 224                         chunk_block++;
 225                 }
 226         }
 227
 228         return 0;
 229 }
 230
 231 /*
 232  * Issue a write BIO to a zone.
 233  */
 234 static void dmz_submit_write_bio(struct dmz_target *dmz, struct dm_zone *zone,
 235                                  struct bio *bio, sector_t chunk_block,
 236                                  unsigned int nr_blocks)
 237 {
 238         struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
 239
 240         /* Setup and submit the BIO */
 241         bio_set_dev(bio, dmz->dev->bdev);
 242         bio->bi_iter.bi_sector = dmz_start_sect(dmz->metadata, zone) + dmz_blk2sect(chunk_block);
 243         atomic_inc(&bioctx->ref);
 244         generic_make_request(bio);
 245
 246         if (dmz_is_seq(zone))
 247                 zone->wp_block += nr_blocks;
 248 }
 249
 250 /*
 251  * Write blocks directly in a data zone, at the write pointer.
 252  * If a buffer zone is assigned, invalidate the blocks written
 253  * in place.
 254  */
 255 static int dmz_handle_direct_write(struct dmz_target *dmz,
 256                                    struct dm_zone *zone, struct bio *bio,
 257                                    sector_t chunk_block,
 258                                    unsigned int nr_blocks)
 259 {
 260         struct dmz_metadata *zmd = dmz->metadata;
 261         struct dm_zone *bzone = zone->bzone;
 262         int ret;
 263
 264         if (dmz_is_readonly(zone))
 265                 return -EROFS;
 266
 267         /* Submit write */
 268         dmz_submit_write_bio(dmz, zone, bio, chunk_block, nr_blocks);
 269
 270         /*
 271          * Validate the blocks in the data zone and invalidate
 272          * in the buffer zone, if there is one.
 273          */
 274         ret = dmz_validate_blocks(zmd, zone, chunk_block, nr_blocks);
 275         if (ret == 0 && bzone)
 276                 ret = dmz_invalidate_blocks(zmd, bzone, chunk_block, nr_blocks);
 277
 278         return ret;
 279 }
 280
 281 /*
 282  * Write blocks in the buffer zone of @zone.
 283  * If no buffer zone is assigned yet, get one.
 284  * Called with @zone write locked.
 285  */
 286 static int dmz_handle_buffered_write(struct dmz_target *dmz,
 287                                      struct dm_zone *zone, struct bio *bio,
 288                                      sector_t chunk_block,
 289                                      unsigned int nr_blocks)
 290 {
 291         struct dmz_metadata *zmd = dmz->metadata;
 292         struct dm_zone *bzone;
 293         int ret;
 294
 295         /* Get the buffer zone. One will be allocated if needed */
 296         bzone = dmz_get_chunk_buffer(zmd, zone);
 297         if (!bzone)
 298                 return -ENOSPC;
 299
 300         if (dmz_is_readonly(bzone))
 301                 return -EROFS;
 302
 303         /* Submit write */
 304         dmz_submit_write_bio(dmz, bzone, bio, chunk_block, nr_blocks);
 305
 306         /*
 307          * Validate the blocks in the buffer zone
 308          * and invalidate in the data zone.
 309          */
 310         ret = dmz_validate_blocks(zmd, bzone, chunk_block, nr_blocks);
 311         if (ret == 0 && chunk_block < zone->wp_block)
 312                 ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks);
 313
 314         return ret;
 315 }
 316
 317 /*
 318  * Process a write BIO.
 319  */
 320 static int dmz_handle_write(struct dmz_target *dmz, struct dm_zone *zone,
 321                             struct bio *bio)
 322 {
 323         sector_t chunk_block = dmz_chunk_block(dmz->dev, dmz_bio_block(bio));
 324         unsigned int nr_blocks = dmz_bio_blocks(bio);
 325
 326         if (!zone)
 327                 return -ENOSPC;
 328
 329         dmz_dev_debug(dmz->dev, "WRITE chunk %llu -> %s zone %u, block %llu, %u blocks",
 330                       (unsigned long long)dmz_bio_chunk(dmz->dev, bio),
 331                       (dmz_is_rnd(zone) ? "RND" : "SEQ"),
 332                       dmz_id(dmz->metadata, zone),
 333                       (unsigned long long)chunk_block, nr_blocks);
 334
 335         if (dmz_is_rnd(zone) || chunk_block == zone->wp_block) {
 336                 /*
 337                  * zone is a random zone or it is a sequential zone
 338                  * and the BIO is aligned to the zone write pointer:
 339                  * direct write the zone.
 340                  */
 341                 return dmz_handle_direct_write(dmz, zone, bio, chunk_block, nr_blocks);
 342         }
 343
 344         /*
 345          * This is an unaligned write in a sequential zone:
 346          * use buffered write.
 347          */
 348         return dmz_handle_buffered_write(dmz, zone, bio, chunk_block, nr_blocks);
 349 }
 350
 351 /*
 352  * Process a discard BIO.
 353  */
 354 static int dmz_handle_discard(struct dmz_target *dmz, struct dm_zone *zone,
 355                               struct bio *bio)
 356 {
 357         struct dmz_metadata *zmd = dmz->metadata;
 358         sector_t block = dmz_bio_block(bio);
 359         unsigned int nr_blocks = dmz_bio_blocks(bio);
 360         sector_t chunk_block = dmz_chunk_block(dmz->dev, block);
 361         int ret = 0;
 362
 363         /* For unmapped chunks, there is nothing to do */
 364         if (!zone)
 365                 return 0;
 366
 367         if (dmz_is_readonly(zone))
 368                 return -EROFS;
 369
 370         dmz_dev_debug(dmz->dev, "DISCARD chunk %llu -> zone %u, block %llu, %u blocks",
 371                       (unsigned long long)dmz_bio_chunk(dmz->dev, bio),
 372                       dmz_id(zmd, zone),
 373                       (unsigned long long)chunk_block, nr_blocks);
 374
 375         /*
 376          * Invalidate blocks in the data zone and its
 377          * buffer zone if one is mapped.
 378          */
 379         if (dmz_is_rnd(zone) || chunk_block < zone->wp_block)
 380                 ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks);
 381         if (ret == 0 && zone->bzone)
 382                 ret = dmz_invalidate_blocks(zmd, zone->bzone,
 383                                             chunk_block, nr_blocks);
 384         return ret;
 385 }
 386
 387 /*
 388  * Process a BIO.
 389  */
 390 static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw,
 391                            struct bio *bio)
 392 {
 393         struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
 394         struct dmz_metadata *zmd = dmz->metadata;
 395         struct dm_zone *zone;
 396         int ret;
 397
 398         /*
 399          * Write may trigger a zone allocation. So make sure the
 400          * allocation can succeed.
 401          */
 402         if (bio_op(bio) == REQ_OP_WRITE)
 403                 dmz_schedule_reclaim(dmz->reclaim);
 404
 405         dmz_lock_metadata(zmd);
 406
 407         /*
 408          * Get the data zone mapping the chunk. There may be no
 409          * mapping for read and discard. If a mapping is obtained,
 410          + the zone returned will be set to active state.
 411          */
 412         zone = dmz_get_chunk_mapping(zmd, dmz_bio_chunk(dmz->dev, bio),
 413                                      bio_op(bio));
 414         if (IS_ERR(zone)) {
 415                 ret = PTR_ERR(zone);
 416                 goto out;
 417         }
 418
 419         /* Process the BIO */
 420         if (zone) {
 421                 dmz_activate_zone(zone);
 422                 bioctx->zone = zone;
 423         }
 424
 425         switch (bio_op(bio)) {
 426         case REQ_OP_READ:
 427                 ret = dmz_handle_read(dmz, zone, bio);
 428                 break;
 429         case REQ_OP_WRITE:
 430                 ret = dmz_handle_write(dmz, zone, bio);
 431                 break;
 432         case REQ_OP_DISCARD:
 433         case REQ_OP_WRITE_ZEROES:
 434                 ret = dmz_handle_discard(dmz, zone, bio);
 435                 break;
 436         default:
 437                 dmz_dev_err(dmz->dev, "Unsupported BIO operation 0x%x",
 438                             bio_op(bio));
 439                 ret = -EIO;
 440         }
 441
 442         /*
 443          * Release the chunk mapping. This will check that the mapping
 444          * is still valid, that is, that the zone used still has valid blocks.
 445          */
 446         if (zone)
 447                 dmz_put_chunk_mapping(zmd, zone);
 448 out:
 449         dmz_bio_endio(bio, errno_to_blk_status(ret));
 450
 451         dmz_unlock_metadata(zmd);
 452 }
 453
 454 /*
 455  * Increment a chunk reference counter.
 456  */
 457 static inline void dmz_get_chunk_work(struct dm_chunk_work *cw)
 458 {
 459         atomic_inc(&cw->refcount);
 460 }
 461
 462 /*
 463  * Decrement a chunk work reference count and
 464  * free it if it becomes 0.
 465  */
 466 static void dmz_put_chunk_work(struct dm_chunk_work *cw)
 467 {
 468         if (atomic_dec_and_test(&cw->refcount)) {
 469                 WARN_ON(!bio_list_empty(&cw->bio_list));
 470                 radix_tree_delete(&cw->target->chunk_rxtree, cw->chunk);
 471                 kfree(cw);
 472         }
 473 }
 474
 475 /*
 476  * Chunk BIO work function.
 477  */
 478 static void dmz_chunk_work(struct work_struct *work)
 479 {
 480         struct dm_chunk_work *cw = container_of(work, struct dm_chunk_work, work);
 481         struct dmz_target *dmz = cw->target;
 482         struct bio *bio;
 483
 484         mutex_lock(&dmz->chunk_lock);
 485
 486         /* Process the chunk BIOs */
 487         while ((bio = bio_list_pop(&cw->bio_list))) {
 488                 mutex_unlock(&dmz->chunk_lock);
 489                 dmz_handle_bio(dmz, cw, bio);
 490                 mutex_lock(&dmz->chunk_lock);
 491                 dmz_put_chunk_work(cw);
 492         }
 493
 494         /* Queueing the work incremented the work refcount */
 495         dmz_put_chunk_work(cw);
 496
 497         mutex_unlock(&dmz->chunk_lock);
 498 }
 499
 500 /*
 501  * Flush work.
 502  */
 503 static void dmz_flush_work(struct work_struct *work)
 504 {
 505         struct dmz_target *dmz = container_of(work, struct dmz_target, flush_work.work);
 506         struct bio *bio;
 507         int ret;
 508
 509         /* Flush dirty metadata blocks */
 510         ret = dmz_flush_metadata(dmz->metadata);
 511
 512         /* Process queued flush requests */
 513         while (1) {
 514                 spin_lock(&dmz->flush_lock);
 515                 bio = bio_list_pop(&dmz->flush_list);
 516                 spin_unlock(&dmz->flush_lock);
 517
 518                 if (!bio)
 519                         break;
 520
 521                 dmz_bio_endio(bio, errno_to_blk_status(ret));
 522         }
 523
 524         queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
 525 }
 526
 527 /*
 528  * Get a chunk work and start it to process a new BIO.
 529  * If the BIO chunk has no work yet, create one.
 530  */
 531 static void dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
 532 {
 533         unsigned int chunk = dmz_bio_chunk(dmz->dev, bio);
 534         struct dm_chunk_work *cw;
 535
 536         mutex_lock(&dmz->chunk_lock);
 537
 538         /* Get the BIO chunk work. If one is not active yet, create one */
 539         cw = radix_tree_lookup(&dmz->chunk_rxtree, chunk);
 540         if (!cw) {
 541                 int ret;
 542
 543                 /* Create a new chunk work */
 544                 cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOIO);
 545                 if (!cw)
 546                         goto out;
 547
 548                 INIT_WORK(&cw->work, dmz_chunk_work);
 549                 atomic_set(&cw->refcount, 0);
 550                 cw->target = dmz;
 551                 cw->chunk = chunk;
 552                 bio_list_init(&cw->bio_list);
 553
 554                 ret = radix_tree_insert(&dmz->chunk_rxtree, chunk, cw);
 555                 if (unlikely(ret)) {
 556                         kfree(cw);
 557                         cw = NULL;
 558                         goto out;
 559                 }
 560         }
 561
 562         bio_list_add(&cw->bio_list, bio);
 563         dmz_get_chunk_work(cw);
 564
 565         if (queue_work(dmz->chunk_wq, &cw->work))
 566                 dmz_get_chunk_work(cw);
 567 out:
 568         mutex_unlock(&dmz->chunk_lock);
 569 }
 570
 571 /*
 572  * Process a new BIO.
 573  */
 574 static int dmz_map(struct dm_target *ti, struct bio *bio)
 575 {
 576         struct dmz_target *dmz = ti->private;
 577         struct dmz_dev *dev = dmz->dev;
 578         struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
 579         sector_t sector = bio->bi_iter.bi_sector;
 580         unsigned int nr_sectors = bio_sectors(bio);
 581         sector_t chunk_sector;
 582
 583         dmz_dev_debug(dev, "BIO op %d sector %llu + %u => chunk %llu, block %llu, %u blocks",
 584                       bio_op(bio), (unsigned long long)sector, nr_sectors,
 585                       (unsigned long long)dmz_bio_chunk(dmz->dev, bio),
 586                       (unsigned long long)dmz_chunk_block(dmz->dev, dmz_bio_block(bio)),
 587                       (unsigned int)dmz_bio_blocks(bio));
 588
 589         bio_set_dev(bio, dev->bdev);
 590
 591         if (!nr_sectors && bio_op(bio) != REQ_OP_WRITE)
 592                 return DM_MAPIO_REMAPPED;
 593
 594         /* The BIO should be block aligned */
 595         if ((nr_sectors & DMZ_BLOCK_SECTORS_MASK) || (sector & DMZ_BLOCK_SECTORS_MASK))
 596                 return DM_MAPIO_KILL;
 597
 598         /* Initialize the BIO context */
 599         bioctx->target = dmz;
 600         bioctx->zone = NULL;
 601         bioctx->bio = bio;
 602         atomic_set(&bioctx->ref, 1);
 603         bioctx->status = BLK_STS_OK;
 604
 605         /* Set the BIO pending in the flush list */
 606         if (!nr_sectors && bio_op(bio) == REQ_OP_WRITE) {
 607                 spin_lock(&dmz->flush_lock);
 608                 bio_list_add(&dmz->flush_list, bio);
 609                 spin_unlock(&dmz->flush_lock);
 610                 mod_delayed_work(dmz->flush_wq, &dmz->flush_work, 0);
 611                 return DM_MAPIO_SUBMITTED;
 612         }
 613
 614         /* Split zone BIOs to fit entirely into a zone */
 615         chunk_sector = sector & (dev->zone_nr_sectors - 1);
 616         if (chunk_sector + nr_sectors > dev->zone_nr_sectors)
 617                 dm_accept_partial_bio(bio, dev->zone_nr_sectors - chunk_sector);
 618
 619         /* Now ready to handle this BIO */
 620         dmz_reclaim_bio_acc(dmz->reclaim);
 621         dmz_queue_chunk_work(dmz, bio);
 622
 623         return DM_MAPIO_SUBMITTED;
 624 }
 625
 626 /*
 627  * Completed target BIO processing.
 628  */
 629 static int dmz_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error)
 630 {
 631         struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
 632
 633         if (bioctx->status == BLK_STS_OK && *error)
 634                 bioctx->status = *error;
 635
 636         if (!atomic_dec_and_test(&bioctx->ref))
 637                 return DM_ENDIO_INCOMPLETE;
 638
 639         /* Done */
 640         bio->bi_status = bioctx->status;
 641
 642         if (bioctx->zone) {
 643                 struct dm_zone *zone = bioctx->zone;
 644
 645                 if (*error && bio_op(bio) == REQ_OP_WRITE) {
 646                         if (dmz_is_seq(zone))
 647                                 set_bit(DMZ_SEQ_WRITE_ERR, &zone->flags);
 648                 }
 649                 dmz_deactivate_zone(zone);
 650         }
 651
 652         return DM_ENDIO_DONE;
 653 }
 654
 655 /*
 656  * Get zoned device information.
 657  */
 658 static int dmz_get_zoned_device(struct dm_target *ti, char *path)
 659 {
 660         struct dmz_target *dmz = ti->private;
 661         struct request_queue *q;
 662         struct dmz_dev *dev;
 663         sector_t aligned_capacity;
 664         int ret;
 665
 666         /* Get the target device */
 667         ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &dmz->ddev);
 668         if (ret) {
 669                 ti->error = "Get target device failed";
 670                 dmz->ddev = NULL;
 671                 return ret;
 672         }
 673
 674         dev = kzalloc(sizeof(struct dmz_dev), GFP_KERNEL);
 675         if (!dev) {
 676                 ret = -ENOMEM;
 677                 goto err;
 678         }
 679
 680         dev->bdev = dmz->ddev->bdev;
 681         (void)bdevname(dev->bdev, dev->name);
 682
 683         if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE) {
 684                 ti->error = "Not a zoned block device";
 685                 ret = -EINVAL;
 686                 goto err;
 687         }
 688
 689         q = bdev_get_queue(dev->bdev);
 690         dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT;
 691         aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1);
 692         if (ti->begin ||
 693             ((ti->len != dev->capacity) && (ti->len != aligned_capacity))) {
 694                 ti->error = "Partial mapping not supported";
 695                 ret = -EINVAL;
 696                 goto err;
 697         }
 698
 699         dev->zone_nr_sectors = blk_queue_zone_sectors(q);
 700         dev->zone_nr_sectors_shift = ilog2(dev->zone_nr_sectors);
 701
 702         dev->zone_nr_blocks = dmz_sect2blk(dev->zone_nr_sectors);
 703         dev->zone_nr_blocks_shift = ilog2(dev->zone_nr_blocks);
 704
 705         dev->nr_zones = (dev->capacity + dev->zone_nr_sectors - 1)
 706                 >> dev->zone_nr_sectors_shift;
 707
 708         dmz->dev = dev;
 709
 710         return 0;
 711 err:
 712         dm_put_device(ti, dmz->ddev);
 713         kfree(dev);
 714
 715         return ret;
 716 }
 717
 718 /*
 719  * Cleanup zoned device information.
 720  */
 721 static void dmz_put_zoned_device(struct dm_target *ti)
 722 {
 723         struct dmz_target *dmz = ti->private;
 724
 725         dm_put_device(ti, dmz->ddev);
 726         kfree(dmz->dev);
 727         dmz->dev = NULL;
 728 }
 729
 730 /*
 731  * Setup target.
 732  */
 733 static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 734 {
 735         struct dmz_target *dmz;
 736         struct dmz_dev *dev;
 737         int ret;
 738
 739         /* Check arguments */
 740         if (argc != 1) {
 741                 ti->error = "Invalid argument count";
 742                 return -EINVAL;
 743         }
 744
 745         /* Allocate and initialize the target descriptor */
 746         dmz = kzalloc(sizeof(struct dmz_target), GFP_KERNEL);
 747         if (!dmz) {
 748                 ti->error = "Unable to allocate the zoned target descriptor";
 749                 return -ENOMEM;
 750         }
 751         ti->private = dmz;
 752
 753         /* Get the target zoned block device */
 754         ret = dmz_get_zoned_device(ti, argv[0]);
 755         if (ret) {
 756                 dmz->ddev = NULL;
 757                 goto err;
 758         }
 759
 760         /* Initialize metadata */
 761         dev = dmz->dev;
 762         ret = dmz_ctr_metadata(dev, &dmz->metadata);
 763         if (ret) {
 764                 ti->error = "Metadata initialization failed";
 765                 goto err_dev;
 766         }
 767
 768         /* Set target (no write same support) */
 769         ti->max_io_len = dev->zone_nr_sectors << 9;
 770         ti->num_flush_bios = 1;
 771         ti->num_discard_bios = 1;
 772         ti->num_write_zeroes_bios = 1;
 773         ti->per_io_data_size = sizeof(struct dmz_bioctx);
 774         ti->flush_supported = true;
 775         ti->discards_supported = true;
 776         ti->split_discard_bios = true;
 777
 778         /* The exposed capacity is the number of chunks that can be mapped */
 779         ti->len = (sector_t)dmz_nr_chunks(dmz->metadata) << dev->zone_nr_sectors_shift;
 780
 781         /* Zone BIO */
 782         dmz->bio_set = bioset_create(DMZ_MIN_BIOS, 0, 0);
 783         if (!dmz->bio_set) {
 784                 ti->error = "Create BIO set failed";
 785                 ret = -ENOMEM;
 786                 goto err_meta;
 787         }
 788
 789         /* Chunk BIO work */
 790         mutex_init(&dmz->chunk_lock);
 791         INIT_RADIX_TREE(&dmz->chunk_rxtree, GFP_KERNEL);
 792         dmz->chunk_wq = alloc_workqueue("dmz_cwq_%s", WQ_MEM_RECLAIM | WQ_UNBOUND,
 793                                         0, dev->name);
 794         if (!dmz->chunk_wq) {
 795                 ti->error = "Create chunk workqueue failed";
 796                 ret = -ENOMEM;
 797                 goto err_bio;
 798         }
 799
 800         /* Flush work */
 801         spin_lock_init(&dmz->flush_lock);
 802         bio_list_init(&dmz->flush_list);
 803         INIT_DELAYED_WORK(&dmz->flush_work, dmz_flush_work);
 804         dmz->flush_wq = alloc_ordered_workqueue("dmz_fwq_%s", WQ_MEM_RECLAIM,
 805                                                 dev->name);
 806         if (!dmz->flush_wq) {
 807                 ti->error = "Create flush workqueue failed";
 808                 ret = -ENOMEM;
 809                 goto err_cwq;
 810         }
 811         mod_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
 812
 813         /* Initialize reclaim */
 814         ret = dmz_ctr_reclaim(dev, dmz->metadata, &dmz->reclaim);
 815         if (ret) {
 816                 ti->error = "Zone reclaim initialization failed";
 817                 goto err_fwq;
 818         }
 819
 820         dmz_dev_info(dev, "Target device: %llu 512-byte logical sectors (%llu blocks)",
 821                      (unsigned long long)ti->len,
 822                      (unsigned long long)dmz_sect2blk(ti->len));
 823
 824         return 0;
 825 err_fwq:
 826         destroy_workqueue(dmz->flush_wq);
 827 err_cwq:
 828         destroy_workqueue(dmz->chunk_wq);
 829 err_bio:
 830         mutex_destroy(&dmz->chunk_lock);
 831         bioset_free(dmz->bio_set);
 832 err_meta:
 833         dmz_dtr_metadata(dmz->metadata);
 834 err_dev:
 835         dmz_put_zoned_device(ti);
 836 err:
 837         kfree(dmz);
 838
 839         return ret;
 840 }
 841
 842 /*
 843  * Cleanup target.
 844  */
 845 static void dmz_dtr(struct dm_target *ti)
 846 {
 847         struct dmz_target *dmz = ti->private;
 848
 849         flush_workqueue(dmz->chunk_wq);
 850         destroy_workqueue(dmz->chunk_wq);
 851
 852         dmz_dtr_reclaim(dmz->reclaim);
 853
 854         cancel_delayed_work_sync(&dmz->flush_work);
 855         destroy_workqueue(dmz->flush_wq);
 856
 857         (void) dmz_flush_metadata(dmz->metadata);
 858
 859         dmz_dtr_metadata(dmz->metadata);
 860
 861         bioset_free(dmz->bio_set);
 862
 863         dmz_put_zoned_device(ti);
 864
 865         mutex_destroy(&dmz->chunk_lock);
 866
 867         kfree(dmz);
 868 }
 869
 870 /*
 871  * Setup target request queue limits.
 872  */
 873 static void dmz_io_hints(struct dm_target *ti, struct queue_limits *limits)
 874 {
 875         struct dmz_target *dmz = ti->private;
 876         unsigned int chunk_sectors = dmz->dev->zone_nr_sectors;
 877
 878         limits->logical_block_size = DMZ_BLOCK_SIZE;
 879         limits->physical_block_size = DMZ_BLOCK_SIZE;
 880
 881         blk_limits_io_min(limits, DMZ_BLOCK_SIZE);
 882         blk_limits_io_opt(limits, DMZ_BLOCK_SIZE);
 883
 884         limits->discard_alignment = DMZ_BLOCK_SIZE;
 885         limits->discard_granularity = DMZ_BLOCK_SIZE;
 886         limits->max_discard_sectors = chunk_sectors;
 887         limits->max_hw_discard_sectors = chunk_sectors;
 888         limits->max_write_zeroes_sectors = chunk_sectors;
 889
 890         /* FS hint to try to align to the device zone size */
 891         limits->chunk_sectors = chunk_sectors;
 892         limits->max_sectors = chunk_sectors;
 893
 894         /* We are exposing a drive-managed zoned block device */
 895         limits->zoned = BLK_ZONED_NONE;
 896 }
 897
 898 /*
 899  * Pass on ioctl to the backend device.
 900  */
 901 static int dmz_prepare_ioctl(struct dm_target *ti,
 902                              struct block_device **bdev, fmode_t *mode)
 903 {
 904         struct dmz_target *dmz = ti->private;
 905
 906         *bdev = dmz->dev->bdev;
 907
 908         return 0;
 909 }
 910
 911 /*
 912  * Stop works on suspend.
 913  */
 914 static void dmz_suspend(struct dm_target *ti)
 915 {
 916         struct dmz_target *dmz = ti->private;
 917
 918         flush_workqueue(dmz->chunk_wq);
 919         dmz_suspend_reclaim(dmz->reclaim);
 920         cancel_delayed_work_sync(&dmz->flush_work);
 921 }
 922
 923 /*
 924  * Restart works on resume or if suspend failed.
 925  */
 926 static void dmz_resume(struct dm_target *ti)
 927 {
 928         struct dmz_target *dmz = ti->private;
 929
 930         queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
 931         dmz_resume_reclaim(dmz->reclaim);
 932 }
 933
 934 static int dmz_iterate_devices(struct dm_target *ti,
 935                                iterate_devices_callout_fn fn, void *data)
 936 {
 937         struct dmz_target *dmz = ti->private;
 938         struct dmz_dev *dev = dmz->dev;
 939         sector_t capacity = dev->capacity & ~(dev->zone_nr_sectors - 1);
 940
 941         return fn(ti, dmz->ddev, 0, capacity, data);
 942 }
 943
 944 static struct target_type dmz_type = {
 945         .name            = "zoned",
 946         .version         = {1, 0, 0},
 947         .features        = DM_TARGET_SINGLETON | DM_TARGET_ZONED_HM,
 948         .module          = THIS_MODULE,
 949         .ctr             = dmz_ctr,
 950         .dtr             = dmz_dtr,
 951         .map             = dmz_map,
 952         .end_io          = dmz_end_io,
 953         .io_hints        = dmz_io_hints,
 954         .prepare_ioctl   = dmz_prepare_ioctl,
 955         .postsuspend     = dmz_suspend,
 956         .resume          = dmz_resume,
 957         .iterate_devices = dmz_iterate_devices,
 958 };
 959
 960 static int __init dmz_init(void)
 961 {
 962         return dm_register_target(&dmz_type);
 963 }
 964
 965 static void __exit dmz_exit(void)
 966 {
 967         dm_unregister_target(&dmz_type);
 968 }
 969
 970 module_init(dmz_init);
 971 module_exit(dmz_exit);
 972
 973 MODULE_DESCRIPTION(DM_NAME " target for zoned block devices");
 974 MODULE_AUTHOR("Damien Le Moal <damien.lemoal@wdc.com>");
 975 MODULE_LICENSE("GPL");