block/blk-zoned.c

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