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