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 #include <linux/mm.h>
  18 #include <linux/vmalloc.h>
  19 #include <linux/sched/mm.h>
  20
  21 #include "blk.h"
  22
  23 #define ZONE_COND_NAME(name) [BLK_ZONE_COND_##name] = #name
  24 static const char *const zone_cond_name[] = {
  25         ZONE_COND_NAME(NOT_WP),
  26         ZONE_COND_NAME(EMPTY),
  27         ZONE_COND_NAME(IMP_OPEN),
  28         ZONE_COND_NAME(EXP_OPEN),
  29         ZONE_COND_NAME(CLOSED),
  30         ZONE_COND_NAME(READONLY),
  31         ZONE_COND_NAME(FULL),
  32         ZONE_COND_NAME(OFFLINE),
  33 };
  34 #undef ZONE_COND_NAME
  35
  36 /**
  37  * blk_zone_cond_str - Return string XXX in BLK_ZONE_COND_XXX.
  38  * @zone_cond: BLK_ZONE_COND_XXX.
  39  *
  40  * Description: Centralize block layer function to convert BLK_ZONE_COND_XXX
  41  * into string format. Useful in the debugging and tracing zone conditions. For
  42  * invalid BLK_ZONE_COND_XXX it returns string "UNKNOWN".
  43  */
  44 const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
  45 {
  46         static const char *zone_cond_str = "UNKNOWN";
  47
  48         if (zone_cond < ARRAY_SIZE(zone_cond_name) && zone_cond_name[zone_cond])
  49                 zone_cond_str = zone_cond_name[zone_cond];
  50
  51         return zone_cond_str;
  52 }
  53 EXPORT_SYMBOL_GPL(blk_zone_cond_str);
  54
  55 static inline sector_t blk_zone_start(struct request_queue *q,
  56                                       sector_t sector)
  57 {
  58         sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
  59
  60         return sector & ~zone_mask;
  61 }
  62
  63 /*
  64  * Return true if a request is a write requests that needs zone write locking.
  65  */
  66 bool blk_req_needs_zone_write_lock(struct request *rq)
  67 {
  68         if (!rq->q->seq_zones_wlock)
  69                 return false;
  70
  71         if (blk_rq_is_passthrough(rq))
  72                 return false;
  73
  74         switch (req_op(rq)) {
  75         case REQ_OP_WRITE_ZEROES:
  76         case REQ_OP_WRITE_SAME:
  77         case REQ_OP_WRITE:
  78                 return blk_rq_zone_is_seq(rq);
  79         default:
  80                 return false;
  81         }
  82 }
  83 EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
  84
  85 bool blk_req_zone_write_trylock(struct request *rq)
  86 {
  87         unsigned int zno = blk_rq_zone_no(rq);
  88
  89         if (test_and_set_bit(zno, rq->q->seq_zones_wlock))
  90                 return false;
  91
  92         WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
  93         rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
  94
  95         return true;
  96 }
  97 EXPORT_SYMBOL_GPL(blk_req_zone_write_trylock);
  98
  99 void __blk_req_zone_write_lock(struct request *rq)
 100 {
 101         if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
 102                                           rq->q->seq_zones_wlock)))
 103                 return;
 104
 105         WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
 106         rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
 107 }
 108 EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
 109
 110 void __blk_req_zone_write_unlock(struct request *rq)
 111 {
 112         rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
 113         if (rq->q->seq_zones_wlock)
 114                 WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
 115                                                  rq->q->seq_zones_wlock));
 116 }
 117 EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
 118
 119 /**
 120  * blkdev_nr_zones - Get number of zones
 121  * @disk:       Target gendisk
 122  *
 123  * Return the total number of zones of a zoned block device.  For a block
 124  * device without zone capabilities, the number of zones is always 0.
 125  */
 126 unsigned int blkdev_nr_zones(struct gendisk *disk)
 127 {
 128         sector_t zone_sectors = blk_queue_zone_sectors(disk->queue);
 129
 130         if (!blk_queue_is_zoned(disk->queue))
 131                 return 0;
 132         return (get_capacity(disk) + zone_sectors - 1) >> ilog2(zone_sectors);
 133 }
 134 EXPORT_SYMBOL_GPL(blkdev_nr_zones);
 135
 136 /**
 137  * blkdev_report_zones - Get zones information
 138  * @bdev:       Target block device
 139  * @sector:     Sector from which to report zones
 140  * @nr_zones:   Maximum number of zones to report
 141  * @cb:         Callback function called for each reported zone
 142  * @data:       Private data for the callback
 143  *
 144  * Description:
 145  *    Get zone information starting from the zone containing @sector for at most
 146  *    @nr_zones, and call @cb for each zone reported by the device.
 147  *    To report all zones in a device starting from @sector, the BLK_ALL_ZONES
 148  *    constant can be passed to @nr_zones.
 149  *    Returns the number of zones reported by the device, or a negative errno
 150  *    value in case of failure.
 151  *
 152  *    Note: The caller must use memalloc_noXX_save/restore() calls to control
 153  *    memory allocations done within this function.
 154  */
 155 int blkdev_report_zones(struct block_device *bdev, sector_t sector,
 156                         unsigned int nr_zones, report_zones_cb cb, void *data)
 157 {
 158         struct gendisk *disk = bdev->bd_disk;
 159         sector_t capacity = get_capacity(disk);
 160
 161         if (!blk_queue_is_zoned(bdev_get_queue(bdev)) ||
 162             WARN_ON_ONCE(!disk->fops->report_zones))
 163                 return -EOPNOTSUPP;
 164
 165         if (!nr_zones || sector >= capacity)
 166                 return 0;
 167
 168         return disk->fops->report_zones(disk, sector, nr_zones, cb, data);
 169 }
 170 EXPORT_SYMBOL_GPL(blkdev_report_zones);
 171
 172 static inline bool blkdev_allow_reset_all_zones(struct block_device *bdev,
 173                                                 sector_t sector,
 174                                                 sector_t nr_sectors)
 175 {
 176         if (!blk_queue_zone_resetall(bdev_get_queue(bdev)))
 177                 return false;
 178
 179         /*
 180          * REQ_OP_ZONE_RESET_ALL can be executed only if the number of sectors
 181          * of the applicable zone range is the entire disk.
 182          */
 183         return !sector && nr_sectors == get_capacity(bdev->bd_disk);
 184 }
 185
 186 /**
 187  * blkdev_zone_mgmt - Execute a zone management operation on a range of zones
 188  * @bdev:       Target block device
 189  * @op:         Operation to be performed on the zones
 190  * @sector:     Start sector of the first zone to operate on
 191  * @nr_sectors: Number of sectors, should be at least the length of one zone and
 192  *              must be zone size aligned.
 193  * @gfp_mask:   Memory allocation flags (for bio_alloc)
 194  *
 195  * Description:
 196  *    Perform the specified operation on the range of zones specified by
 197  *    @sector..@sector+@nr_sectors. Specifying the entire disk sector range
 198  *    is valid, but the specified range should not contain conventional zones.
 199  *    The operation to execute on each zone can be a zone reset, open, close
 200  *    or finish request.
 201  */
 202 int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
 203                      sector_t sector, sector_t nr_sectors,
 204                      gfp_t gfp_mask)
 205 {
 206         struct request_queue *q = bdev_get_queue(bdev);
 207         sector_t zone_sectors = blk_queue_zone_sectors(q);
 208         sector_t capacity = get_capacity(bdev->bd_disk);
 209         sector_t end_sector = sector + nr_sectors;
 210         struct bio *bio = NULL;
 211         int ret;
 212
 213         if (!blk_queue_is_zoned(q))
 214                 return -EOPNOTSUPP;
 215
 216         if (bdev_read_only(bdev))
 217                 return -EPERM;
 218
 219         if (!op_is_zone_mgmt(op))
 220                 return -EOPNOTSUPP;
 221
 222         if (end_sector <= sector || end_sector > capacity)
 223                 /* Out of range */
 224                 return -EINVAL;
 225
 226         /* Check alignment (handle eventual smaller last zone) */
 227         if (sector & (zone_sectors - 1))
 228                 return -EINVAL;
 229
 230         if ((nr_sectors & (zone_sectors - 1)) && end_sector != capacity)
 231                 return -EINVAL;
 232
 233         while (sector < end_sector) {
 234                 bio = blk_next_bio(bio, 0, gfp_mask);
 235                 bio_set_dev(bio, bdev);
 236
 237                 /*
 238                  * Special case for the zone reset operation that reset all
 239                  * zones, this is useful for applications like mkfs.
 240                  */
 241                 if (op == REQ_OP_ZONE_RESET &&
 242                     blkdev_allow_reset_all_zones(bdev, sector, nr_sectors)) {
 243                         bio->bi_opf = REQ_OP_ZONE_RESET_ALL;
 244                         break;
 245                 }
 246
 247                 bio->bi_opf = op | REQ_SYNC;
 248                 bio->bi_iter.bi_sector = sector;
 249                 sector += zone_sectors;
 250
 251                 /* This may take a while, so be nice to others */
 252                 cond_resched();
 253         }
 254
 255         ret = submit_bio_wait(bio);
 256         bio_put(bio);
 257
 258         return ret;
 259 }
 260 EXPORT_SYMBOL_GPL(blkdev_zone_mgmt);
 261
 262 struct zone_report_args {
 263         struct blk_zone __user *zones;
 264 };
 265
 266 static int blkdev_copy_zone_to_user(struct blk_zone *zone, unsigned int idx,
 267                                     void *data)
 268 {
 269         struct zone_report_args *args = data;
 270
 271         if (copy_to_user(&args->zones[idx], zone, sizeof(struct blk_zone)))
 272                 return -EFAULT;
 273         return 0;
 274 }
 275
 276 /*
 277  * BLKREPORTZONE ioctl processing.
 278  * Called from blkdev_ioctl.
 279  */
 280 int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 281                               unsigned int cmd, unsigned long arg)
 282 {
 283         void __user *argp = (void __user *)arg;
 284         struct zone_report_args args;
 285         struct request_queue *q;
 286         struct blk_zone_report rep;
 287         int ret;
 288
 289         if (!argp)
 290                 return -EINVAL;
 291
 292         q = bdev_get_queue(bdev);
 293         if (!q)
 294                 return -ENXIO;
 295
 296         if (!blk_queue_is_zoned(q))
 297                 return -ENOTTY;
 298
 299         if (!capable(CAP_SYS_ADMIN))
 300                 return -EACCES;
 301
 302         if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
 303                 return -EFAULT;
 304
 305         if (!rep.nr_zones)
 306                 return -EINVAL;
 307
 308         args.zones = argp + sizeof(struct blk_zone_report);
 309         ret = blkdev_report_zones(bdev, rep.sector, rep.nr_zones,
 310                                   blkdev_copy_zone_to_user, &args);
 311         if (ret < 0)
 312                 return ret;
 313
 314         rep.nr_zones = ret;
 315         if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report)))
 316                 return -EFAULT;
 317         return 0;
 318 }
 319
 320 /*
 321  * BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
 322  * Called from blkdev_ioctl.
 323  */
 324 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
 325                            unsigned int cmd, unsigned long arg)
 326 {
 327         void __user *argp = (void __user *)arg;
 328         struct request_queue *q;
 329         struct blk_zone_range zrange;
 330         enum req_opf op;
 331
 332         if (!argp)
 333                 return -EINVAL;
 334
 335         q = bdev_get_queue(bdev);
 336         if (!q)
 337                 return -ENXIO;
 338
 339         if (!blk_queue_is_zoned(q))
 340                 return -ENOTTY;
 341
 342         if (!capable(CAP_SYS_ADMIN))
 343                 return -EACCES;
 344
 345         if (!(mode & FMODE_WRITE))
 346                 return -EBADF;
 347
 348         if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
 349                 return -EFAULT;
 350
 351         switch (cmd) {
 352         case BLKRESETZONE:
 353                 op = REQ_OP_ZONE_RESET;
 354                 break;
 355         case BLKOPENZONE:
 356                 op = REQ_OP_ZONE_OPEN;
 357                 break;
 358         case BLKCLOSEZONE:
 359                 op = REQ_OP_ZONE_CLOSE;
 360                 break;
 361         case BLKFINISHZONE:
 362                 op = REQ_OP_ZONE_FINISH;
 363                 break;
 364         default:
 365                 return -ENOTTY;
 366         }
 367
 368         return blkdev_zone_mgmt(bdev, op, zrange.sector, zrange.nr_sectors,
 369                                 GFP_KERNEL);
 370 }
 371
 372 static inline unsigned long *blk_alloc_zone_bitmap(int node,
 373                                                    unsigned int nr_zones)
 374 {
 375         return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
 376                             GFP_NOIO, node);
 377 }
 378
 379 void blk_queue_free_zone_bitmaps(struct request_queue *q)
 380 {
 381         kfree(q->conv_zones_bitmap);
 382         q->conv_zones_bitmap = NULL;
 383         kfree(q->seq_zones_wlock);
 384         q->seq_zones_wlock = NULL;
 385 }
 386
 387 struct blk_revalidate_zone_args {
 388         struct gendisk  *disk;
 389         unsigned long   *conv_zones_bitmap;
 390         unsigned long   *seq_zones_wlock;
 391         unsigned int    nr_zones;
 392         sector_t        zone_sectors;
 393         sector_t        sector;
 394 };
 395
 396 /*
 397  * Helper function to check the validity of zones of a zoned block device.
 398  */
 399 static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
 400                                   void *data)
 401 {
 402         struct blk_revalidate_zone_args *args = data;
 403         struct gendisk *disk = args->disk;
 404         struct request_queue *q = disk->queue;
 405         sector_t capacity = get_capacity(disk);
 406
 407         /*
 408          * All zones must have the same size, with the exception on an eventual
 409          * smaller last zone.
 410          */
 411         if (zone->start == 0) {
 412                 if (zone->len == 0 || !is_power_of_2(zone->len)) {
 413                         pr_warn("%s: Invalid zoned device with non power of two zone size (%llu)\n",
 414                                 disk->disk_name, zone->len);
 415                         return -ENODEV;
 416                 }
 417
 418                 args->zone_sectors = zone->len;
 419                 args->nr_zones = (capacity + zone->len - 1) >> ilog2(zone->len);
 420         } else if (zone->start + args->zone_sectors < capacity) {
 421                 if (zone->len != args->zone_sectors) {
 422                         pr_warn("%s: Invalid zoned device with non constant zone size\n",
 423                                 disk->disk_name);
 424                         return -ENODEV;
 425                 }
 426         } else {
 427                 if (zone->len > args->zone_sectors) {
 428                         pr_warn("%s: Invalid zoned device with larger last zone size\n",
 429                                 disk->disk_name);
 430                         return -ENODEV;
 431                 }
 432         }
 433
 434         /* Check for holes in the zone report */
 435         if (zone->start != args->sector) {
 436                 pr_warn("%s: Zone gap at sectors %llu..%llu\n",
 437                         disk->disk_name, args->sector, zone->start);
 438                 return -ENODEV;
 439         }
 440
 441         /* Check zone type */
 442         switch (zone->type) {
 443         case BLK_ZONE_TYPE_CONVENTIONAL:
 444                 if (!args->conv_zones_bitmap) {
 445                         args->conv_zones_bitmap =
 446                                 blk_alloc_zone_bitmap(q->node, args->nr_zones);
 447                         if (!args->conv_zones_bitmap)
 448                                 return -ENOMEM;
 449                 }
 450                 set_bit(idx, args->conv_zones_bitmap);
 451                 break;
 452         case BLK_ZONE_TYPE_SEQWRITE_REQ:
 453         case BLK_ZONE_TYPE_SEQWRITE_PREF:
 454                 if (!args->seq_zones_wlock) {
 455                         args->seq_zones_wlock =
 456                                 blk_alloc_zone_bitmap(q->node, args->nr_zones);
 457                         if (!args->seq_zones_wlock)
 458                                 return -ENOMEM;
 459                 }
 460                 break;
 461         default:
 462                 pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
 463                         disk->disk_name, (int)zone->type, zone->start);
 464                 return -ENODEV;
 465         }
 466
 467         args->sector += zone->len;
 468         return 0;
 469 }
 470
 471 /**
 472  * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
 473  * @disk:       Target disk
 474  * @update_driver_data: Callback to update driver data on the frozen disk
 475  *
 476  * Helper function for low-level device drivers to (re) allocate and initialize
 477  * a disk request queue zone bitmaps. This functions should normally be called
 478  * within the disk ->revalidate method for blk-mq based drivers.  For BIO based
 479  * drivers only q->nr_zones needs to be updated so that the sysfs exposed value
 480  * is correct.
 481  * If the @update_driver_data callback function is not NULL, the callback is
 482  * executed with the device request queue frozen after all zones have been
 483  * checked.
 484  */
 485 int blk_revalidate_disk_zones(struct gendisk *disk,
 486                               void (*update_driver_data)(struct gendisk *disk))
 487 {
 488         struct request_queue *q = disk->queue;
 489         struct blk_revalidate_zone_args args = {
 490                 .disk           = disk,
 491         };
 492         unsigned int noio_flag;
 493         int ret;
 494
 495         if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
 496                 return -EIO;
 497         if (WARN_ON_ONCE(!queue_is_mq(q)))
 498                 return -EIO;
 499
 500         if (!get_capacity(disk))
 501                 return -EIO;
 502
 503         /*
 504          * Ensure that all memory allocations in this context are done as if
 505          * GFP_NOIO was specified.
 506          */
 507         noio_flag = memalloc_noio_save();
 508         ret = disk->fops->report_zones(disk, 0, UINT_MAX,
 509                                        blk_revalidate_zone_cb, &args);
 510         memalloc_noio_restore(noio_flag);
 511
 512         /*
 513          * Install the new bitmaps and update nr_zones only once the queue is
 514          * stopped and all I/Os are completed (i.e. a scheduler is not
 515          * referencing the bitmaps).
 516          */
 517         blk_mq_freeze_queue(q);
 518         if (ret >= 0) {
 519                 blk_queue_chunk_sectors(q, args.zone_sectors);
 520                 q->nr_zones = args.nr_zones;
 521                 swap(q->seq_zones_wlock, args.seq_zones_wlock);
 522                 swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
 523                 if (update_driver_data)
 524                         update_driver_data(disk);
 525                 ret = 0;
 526         } else {
 527                 pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
 528                 blk_queue_free_zone_bitmaps(q);
 529         }
 530         blk_mq_unfreeze_queue(q);
 531
 532         kfree(args.seq_zones_wlock);
 533         kfree(args.conv_zones_bitmap);
 534         return ret;
 535 }
 536 EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);