block/blk-zoned.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Zoned block device handling
   4  *
   5  * Copyright (c) 2015, Hannes Reinecke
   6  * Copyright (c) 2015, SUSE Linux GmbH
   7  *
   8  * Copyright (c) 2016, Damien Le Moal
   9  * Copyright (c) 2016, Western Digital
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/rbtree.h>
  15 #include <linux/blkdev.h>
  16 #include <linux/blk-mq.h>
  17
  18 #include "blk.h"
  19
  20 static inline sector_t blk_zone_start(struct request_queue *q,
  21                                       sector_t sector)
  22 {
  23         sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
  24
  25         return sector & ~zone_mask;
  26 }
  27
  28 /*
  29  * Return true if a request is a write requests that needs zone write locking.
  30  */
  31 bool blk_req_needs_zone_write_lock(struct request *rq)
  32 {
  33         if (!rq->q->seq_zones_wlock)
  34                 return false;
  35
  36         if (blk_rq_is_passthrough(rq))
  37                 return false;
  38
  39         switch (req_op(rq)) {
  40         case REQ_OP_WRITE_ZEROES:
  41         case REQ_OP_WRITE_SAME:
  42         case REQ_OP_WRITE:
  43                 return blk_rq_zone_is_seq(rq);
  44         default:
  45                 return false;
  46         }
  47 }
  48 EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
  49
  50 void __blk_req_zone_write_lock(struct request *rq)
  51 {
  52         if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
  53                                           rq->q->seq_zones_wlock)))
  54                 return;
  55
  56         WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
  57         rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
  58 }
  59 EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
  60
  61 void __blk_req_zone_write_unlock(struct request *rq)
  62 {
  63         rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
  64         if (rq->q->seq_zones_wlock)
  65                 WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
  66                                                  rq->q->seq_zones_wlock));
  67 }
  68 EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
  69
  70 static inline unsigned int __blkdev_nr_zones(struct request_queue *q,
  71                                              sector_t nr_sectors)
  72 {
  73         unsigned long zone_sectors = blk_queue_zone_sectors(q);
  74
  75         return (nr_sectors + zone_sectors - 1) >> ilog2(zone_sectors);
  76 }
  77
  78 /**
  79  * blkdev_nr_zones - Get number of zones
  80  * @bdev:       Target block device
  81  *
  82  * Description:
  83  *    Return the total number of zones of a zoned block device.
  84  *    For a regular block device, the number of zones is always 0.
  85  */
  86 unsigned int blkdev_nr_zones(struct block_device *bdev)
  87 {
  88         struct request_queue *q = bdev_get_queue(bdev);
  89
  90         if (!blk_queue_is_zoned(q))
  91                 return 0;
  92
  93         return __blkdev_nr_zones(q, bdev->bd_part->nr_sects);
  94 }
  95 EXPORT_SYMBOL_GPL(blkdev_nr_zones);
  96
  97 /*
  98  * Check that a zone report belongs to this partition, and if yes, fix its start
  99  * sector and write pointer and return true. Return false otherwise.
 100  */
 101 static bool blkdev_report_zone(struct block_device *bdev, struct blk_zone *rep)
 102 {
 103         sector_t offset = get_start_sect(bdev);
 104
 105         if (rep->start < offset)
 106                 return false;
 107
 108         rep->start -= offset;
 109         if (rep->start + rep->len > bdev->bd_part->nr_sects)
 110                 return false;
 111
 112         if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
 113                 rep->wp = rep->start + rep->len;
 114         else
 115                 rep->wp -= offset;
 116         return true;
 117 }
 118
 119 static int blk_report_zones(struct gendisk *disk, sector_t sector,
 120                             struct blk_zone *zones, unsigned int *nr_zones,
 121                             gfp_t gfp_mask)
 122 {
 123         struct request_queue *q = disk->queue;
 124         unsigned int z = 0, n, nrz = *nr_zones;
 125         sector_t capacity = get_capacity(disk);
 126         int ret;
 127
 128         while (z < nrz && sector < capacity) {
 129                 n = nrz - z;
 130                 ret = disk->fops->report_zones(disk, sector, &zones[z], &n,
 131                                                gfp_mask);
 132                 if (ret)
 133                         return ret;
 134                 if (!n)
 135                         break;
 136                 sector += blk_queue_zone_sectors(q) * n;
 137                 z += n;
 138         }
 139
 140         WARN_ON(z > *nr_zones);
 141         *nr_zones = z;
 142
 143         return 0;
 144 }
 145
 146 /**
 147  * blkdev_report_zones - Get zones information
 148  * @bdev:       Target block device
 149  * @sector:     Sector from which to report zones
 150  * @zones:      Array of zone structures where to return the zones information
 151  * @nr_zones:   Number of zone structures in the zone array
 152  * @gfp_mask:   Memory allocation flags (for bio_alloc)
 153  *
 154  * Description:
 155  *    Get zone information starting from the zone containing @sector.
 156  *    The number of zone information reported may be less than the number
 157  *    requested by @nr_zones. The number of zones actually reported is
 158  *    returned in @nr_zones.
 159  */
 160 int blkdev_report_zones(struct block_device *bdev, sector_t sector,
 161                         struct blk_zone *zones, unsigned int *nr_zones,
 162                         gfp_t gfp_mask)
 163 {
 164         struct request_queue *q = bdev_get_queue(bdev);
 165         unsigned int i, nrz;
 166         int ret;
 167
 168         if (!blk_queue_is_zoned(q))
 169                 return -EOPNOTSUPP;
 170
 171         /*
 172          * A block device that advertized itself as zoned must have a
 173          * report_zones method. If it does not have one defined, the device
 174          * driver has a bug. So warn about that.
 175          */
 176         if (WARN_ON_ONCE(!bdev->bd_disk->fops->report_zones))
 177                 return -EOPNOTSUPP;
 178
 179         if (!*nr_zones || sector >= bdev->bd_part->nr_sects) {
 180                 *nr_zones = 0;
 181                 return 0;
 182         }
 183
 184         nrz = min(*nr_zones,
 185                   __blkdev_nr_zones(q, bdev->bd_part->nr_sects - sector));
 186         ret = blk_report_zones(bdev->bd_disk, get_start_sect(bdev) + sector,
 187                                zones, &nrz, gfp_mask);
 188         if (ret)
 189                 return ret;
 190
 191         for (i = 0; i < nrz; i++) {
 192                 if (!blkdev_report_zone(bdev, zones))
 193                         break;
 194                 zones++;
 195         }
 196
 197         *nr_zones = i;
 198
 199         return 0;
 200 }
 201 EXPORT_SYMBOL_GPL(blkdev_report_zones);
 202
 203 /**
 204  * blkdev_reset_zones - Reset zones write pointer
 205  * @bdev:       Target block device
 206  * @sector:     Start sector of the first zone to reset
 207  * @nr_sectors: Number of sectors, at least the length of one zone
 208  * @gfp_mask:   Memory allocation flags (for bio_alloc)
 209  *
 210  * Description:
 211  *    Reset the write pointer of the zones contained in the range
 212  *    @sector..@sector+@nr_sectors. Specifying the entire disk sector range
 213  *    is valid, but the specified range should not contain conventional zones.
 214  */
 215 int blkdev_reset_zones(struct block_device *bdev,
 216                        sector_t sector, sector_t nr_sectors,
 217                        gfp_t gfp_mask)
 218 {
 219         struct request_queue *q = bdev_get_queue(bdev);
 220         sector_t zone_sectors;
 221         sector_t end_sector = sector + nr_sectors;
 222         struct bio *bio = NULL;
 223         struct blk_plug plug;
 224         int ret;
 225
 226         if (!blk_queue_is_zoned(q))
 227                 return -EOPNOTSUPP;
 228
 229         if (bdev_read_only(bdev))
 230                 return -EPERM;
 231
 232         if (!nr_sectors || end_sector > bdev->bd_part->nr_sects)
 233                 /* Out of range */
 234                 return -EINVAL;
 235
 236         /* Check alignment (handle eventual smaller last zone) */
 237         zone_sectors = blk_queue_zone_sectors(q);
 238         if (sector & (zone_sectors - 1))
 239                 return -EINVAL;
 240
 241         if ((nr_sectors & (zone_sectors - 1)) &&
 242             end_sector != bdev->bd_part->nr_sects)
 243                 return -EINVAL;
 244
 245         blk_start_plug(&plug);
 246         while (sector < end_sector) {
 247
 248                 bio = blk_next_bio(bio, 0, gfp_mask);
 249                 bio->bi_iter.bi_sector = sector;
 250                 bio_set_dev(bio, bdev);
 251                 bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
 252
 253                 sector += zone_sectors;
 254
 255                 /* This may take a while, so be nice to others */
 256                 cond_resched();
 257
 258         }
 259
 260         ret = submit_bio_wait(bio);
 261         bio_put(bio);
 262
 263         blk_finish_plug(&plug);
 264
 265         return ret;
 266 }
 267 EXPORT_SYMBOL_GPL(blkdev_reset_zones);
 268
 269 /*
 270  * BLKREPORTZONE ioctl processing.
 271  * Called from blkdev_ioctl.
 272  */
 273 int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 274                               unsigned int cmd, unsigned long arg)
 275 {
 276         void __user *argp = (void __user *)arg;
 277         struct request_queue *q;
 278         struct blk_zone_report rep;
 279         struct blk_zone *zones;
 280         int ret;
 281
 282         if (!argp)
 283                 return -EINVAL;
 284
 285         q = bdev_get_queue(bdev);
 286         if (!q)
 287                 return -ENXIO;
 288
 289         if (!blk_queue_is_zoned(q))
 290                 return -ENOTTY;
 291
 292         if (!capable(CAP_SYS_ADMIN))
 293                 return -EACCES;
 294
 295         if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
 296                 return -EFAULT;
 297
 298         if (!rep.nr_zones)
 299                 return -EINVAL;
 300
 301         rep.nr_zones = min(blkdev_nr_zones(bdev), rep.nr_zones);
 302
 303         zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
 304                                GFP_KERNEL | __GFP_ZERO);
 305         if (!zones)
 306                 return -ENOMEM;
 307
 308         ret = blkdev_report_zones(bdev, rep.sector,
 309                                   zones, &rep.nr_zones,
 310                                   GFP_KERNEL);
 311         if (ret)
 312                 goto out;
 313
 314         if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
 315                 ret = -EFAULT;
 316                 goto out;
 317         }
 318
 319         if (rep.nr_zones) {
 320                 if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
 321                                  sizeof(struct blk_zone) * rep.nr_zones))
 322                         ret = -EFAULT;
 323         }
 324
 325  out:
 326         kvfree(zones);
 327
 328         return ret;
 329 }
 330
 331 /*
 332  * BLKRESETZONE ioctl processing.
 333  * Called from blkdev_ioctl.
 334  */
 335 int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
 336                              unsigned int cmd, unsigned long arg)
 337 {
 338         void __user *argp = (void __user *)arg;
 339         struct request_queue *q;
 340         struct blk_zone_range zrange;
 341
 342         if (!argp)
 343                 return -EINVAL;
 344
 345         q = bdev_get_queue(bdev);
 346         if (!q)
 347                 return -ENXIO;
 348
 349         if (!blk_queue_is_zoned(q))
 350                 return -ENOTTY;
 351
 352         if (!capable(CAP_SYS_ADMIN))
 353                 return -EACCES;
 354
 355         if (!(mode & FMODE_WRITE))
 356                 return -EBADF;
 357
 358         if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
 359                 return -EFAULT;
 360
 361         return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
 362                                   GFP_KERNEL);
 363 }
 364
 365 static inline unsigned long *blk_alloc_zone_bitmap(int node,
 366                                                    unsigned int nr_zones)
 367 {
 368         return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
 369                             GFP_NOIO, node);
 370 }
 371
 372 /*
 373  * Allocate an array of struct blk_zone to get nr_zones zone information.
 374  * The allocated array may be smaller than nr_zones.
 375  */
 376 static struct blk_zone *blk_alloc_zones(int node, unsigned int *nr_zones)
 377 {
 378         size_t size = *nr_zones * sizeof(struct blk_zone);
 379         struct page *page;
 380         int order;
 381
 382         for (order = get_order(size); order >= 0; order--) {
 383                 page = alloc_pages_node(node, GFP_NOIO | __GFP_ZERO, order);
 384                 if (page) {
 385                         *nr_zones = min_t(unsigned int, *nr_zones,
 386                                 (PAGE_SIZE << order) / sizeof(struct blk_zone));
 387                         return page_address(page);
 388                 }
 389         }
 390
 391         return NULL;
 392 }
 393
 394 void blk_queue_free_zone_bitmaps(struct request_queue *q)
 395 {
 396         kfree(q->seq_zones_bitmap);
 397         q->seq_zones_bitmap = NULL;
 398         kfree(q->seq_zones_wlock);
 399         q->seq_zones_wlock = NULL;
 400 }
 401
 402 /**
 403  * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
 404  * @disk:       Target disk
 405  *
 406  * Helper function for low-level device drivers to (re) allocate and initialize
 407  * a disk request queue zone bitmaps. This functions should normally be called
 408  * within the disk ->revalidate method. For BIO based queues, no zone bitmap
 409  * is allocated.
 410  */
 411 int blk_revalidate_disk_zones(struct gendisk *disk)
 412 {
 413         struct request_queue *q = disk->queue;
 414         unsigned int nr_zones = __blkdev_nr_zones(q, get_capacity(disk));
 415         unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
 416         unsigned int i, rep_nr_zones = 0, z = 0, nrz;
 417         struct blk_zone *zones = NULL;
 418         sector_t sector = 0;
 419         int ret = 0;
 420
 421         /*
 422          * BIO based queues do not use a scheduler so only q->nr_zones
 423          * needs to be updated so that the sysfs exposed value is correct.
 424          */
 425         if (!queue_is_mq(q)) {
 426                 q->nr_zones = nr_zones;
 427                 return 0;
 428         }
 429
 430         if (!blk_queue_is_zoned(q) || !nr_zones) {
 431                 nr_zones = 0;
 432                 goto update;
 433         }
 434
 435         /* Allocate bitmaps */
 436         ret = -ENOMEM;
 437         seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
 438         if (!seq_zones_wlock)
 439                 goto out;
 440         seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
 441         if (!seq_zones_bitmap)
 442                 goto out;
 443
 444         /* Get zone information and initialize seq_zones_bitmap */
 445         rep_nr_zones = nr_zones;
 446         zones = blk_alloc_zones(q->node, &rep_nr_zones);
 447         if (!zones)
 448                 goto out;
 449
 450         while (z < nr_zones) {
 451                 nrz = min(nr_zones - z, rep_nr_zones);
 452                 ret = blk_report_zones(disk, sector, zones, &nrz, GFP_NOIO);
 453                 if (ret)
 454                         goto out;
 455                 if (!nrz)
 456                         break;
 457                 for (i = 0; i < nrz; i++) {
 458                         if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
 459                                 set_bit(z, seq_zones_bitmap);
 460                         z++;
 461                 }
 462                 sector += nrz * blk_queue_zone_sectors(q);
 463         }
 464
 465         if (WARN_ON(z != nr_zones)) {
 466                 ret = -EIO;
 467                 goto out;
 468         }
 469
 470 update:
 471         /*
 472          * Install the new bitmaps, making sure the queue is stopped and
 473          * all I/Os are completed (i.e. a scheduler is not referencing the
 474          * bitmaps).
 475          */
 476         blk_mq_freeze_queue(q);
 477         q->nr_zones = nr_zones;
 478         swap(q->seq_zones_wlock, seq_zones_wlock);
 479         swap(q->seq_zones_bitmap, seq_zones_bitmap);
 480         blk_mq_unfreeze_queue(q);
 481
 482 out:
 483         free_pages((unsigned long)zones,
 484                    get_order(rep_nr_zones * sizeof(struct blk_zone)));
 485         kfree(seq_zones_wlock);
 486         kfree(seq_zones_bitmap);
 487
 488         if (ret) {
 489                 pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
 490                 blk_mq_freeze_queue(q);
 491                 blk_queue_free_zone_bitmaps(q);
 492                 blk_mq_unfreeze_queue(q);
 493         }
 494
 495         return ret;
 496 }
 497 EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
 498