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
  16 static inline sector_t blk_zone_start(struct request_queue *q,
  17                                       sector_t sector)
  18 {
  19         sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
  20
  21         return sector & ~zone_mask;
  22 }
  23
  24 /*
  25  * Return true if a request is a write requests that needs zone write locking.
  26  */
  27 bool blk_req_needs_zone_write_lock(struct request *rq)
  28 {
  29         if (!rq->q->seq_zones_wlock)
  30                 return false;
  31
  32         if (blk_rq_is_passthrough(rq))
  33                 return false;
  34
  35         switch (req_op(rq)) {
  36         case REQ_OP_WRITE_ZEROES:
  37         case REQ_OP_WRITE_SAME:
  38         case REQ_OP_WRITE:
  39                 return blk_rq_zone_is_seq(rq);
  40         default:
  41                 return false;
  42         }
  43 }
  44 EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
  45
  46 void __blk_req_zone_write_lock(struct request *rq)
  47 {
  48         if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
  49                                           rq->q->seq_zones_wlock)))
  50                 return;
  51
  52         WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
  53         rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
  54 }
  55 EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
  56
  57 void __blk_req_zone_write_unlock(struct request *rq)
  58 {
  59         rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
  60         if (rq->q->seq_zones_wlock)
  61                 WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
  62                                                  rq->q->seq_zones_wlock));
  63 }
  64 EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
  65
  66 /*
  67  * Check that a zone report belongs to the partition.
  68  * If yes, fix its start sector and write pointer, copy it in the
  69  * zone information array and return true. Return false otherwise.
  70  */
  71 static bool blkdev_report_zone(struct block_device *bdev,
  72                                struct blk_zone *rep,
  73                                struct blk_zone *zone)
  74 {
  75         sector_t offset = get_start_sect(bdev);
  76
  77         if (rep->start < offset)
  78                 return false;
  79
  80         rep->start -= offset;
  81         if (rep->start + rep->len > bdev->bd_part->nr_sects)
  82                 return false;
  83
  84         if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
  85                 rep->wp = rep->start + rep->len;
  86         else
  87                 rep->wp -= offset;
  88         memcpy(zone, rep, sizeof(struct blk_zone));
  89
  90         return true;
  91 }
  92
  93 /**
  94  * blkdev_report_zones - Get zones information
  95  * @bdev:       Target block device
  96  * @sector:     Sector from which to report zones
  97  * @zones:      Array of zone structures where to return the zones information
  98  * @nr_zones:   Number of zone structures in the zone array
  99  * @gfp_mask:   Memory allocation flags (for bio_alloc)
 100  *
 101  * Description:
 102  *    Get zone information starting from the zone containing @sector.
 103  *    The number of zone information reported may be less than the number
 104  *    requested by @nr_zones. The number of zones actually reported is
 105  *    returned in @nr_zones.
 106  */
 107 int blkdev_report_zones(struct block_device *bdev,
 108                         sector_t sector,
 109                         struct blk_zone *zones,
 110                         unsigned int *nr_zones,
 111                         gfp_t gfp_mask)
 112 {
 113         struct request_queue *q = bdev_get_queue(bdev);
 114         struct blk_zone_report_hdr *hdr;
 115         unsigned int nrz = *nr_zones;
 116         struct page *page;
 117         unsigned int nr_rep;
 118         size_t rep_bytes;
 119         unsigned int nr_pages;
 120         struct bio *bio;
 121         struct bio_vec *bv;
 122         unsigned int i, n, nz;
 123         unsigned int ofst;
 124         void *addr;
 125         int ret;
 126
 127         if (!q)
 128                 return -ENXIO;
 129
 130         if (!blk_queue_is_zoned(q))
 131                 return -EOPNOTSUPP;
 132
 133         if (!nrz)
 134                 return 0;
 135
 136         if (sector > bdev->bd_part->nr_sects) {
 137                 *nr_zones = 0;
 138                 return 0;
 139         }
 140
 141         /*
 142          * The zone report has a header. So make room for it in the
 143          * payload. Also make sure that the report fits in a single BIO
 144          * that will not be split down the stack.
 145          */
 146         rep_bytes = sizeof(struct blk_zone_report_hdr) +
 147                 sizeof(struct blk_zone) * nrz;
 148         rep_bytes = (rep_bytes + PAGE_SIZE - 1) & PAGE_MASK;
 149         if (rep_bytes > (queue_max_sectors(q) << 9))
 150                 rep_bytes = queue_max_sectors(q) << 9;
 151
 152         nr_pages = min_t(unsigned int, BIO_MAX_PAGES,
 153                          rep_bytes >> PAGE_SHIFT);
 154         nr_pages = min_t(unsigned int, nr_pages,
 155                          queue_max_segments(q));
 156
 157         bio = bio_alloc(gfp_mask, nr_pages);
 158         if (!bio)
 159                 return -ENOMEM;
 160
 161         bio_set_dev(bio, bdev);
 162         bio->bi_iter.bi_sector = blk_zone_start(q, sector);
 163         bio_set_op_attrs(bio, REQ_OP_ZONE_REPORT, 0);
 164
 165         for (i = 0; i < nr_pages; i++) {
 166                 page = alloc_page(gfp_mask);
 167                 if (!page) {
 168                         ret = -ENOMEM;
 169                         goto out;
 170                 }
 171                 if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
 172                         __free_page(page);
 173                         break;
 174                 }
 175         }
 176
 177         if (i == 0)
 178                 ret = -ENOMEM;
 179         else
 180                 ret = submit_bio_wait(bio);
 181         if (ret)
 182                 goto out;
 183
 184         /*
 185          * Process the report result: skip the header and go through the
 186          * reported zones to fixup and fixup the zone information for
 187          * partitions. At the same time, return the zone information into
 188          * the zone array.
 189          */
 190         n = 0;
 191         nz = 0;
 192         nr_rep = 0;
 193         bio_for_each_segment_all(bv, bio, i) {
 194
 195                 if (!bv->bv_page)
 196                         break;
 197
 198                 addr = kmap_atomic(bv->bv_page);
 199
 200                 /* Get header in the first page */
 201                 ofst = 0;
 202                 if (!nr_rep) {
 203                         hdr = addr;
 204                         nr_rep = hdr->nr_zones;
 205                         ofst = sizeof(struct blk_zone_report_hdr);
 206                 }
 207
 208                 /* Fixup and report zones */
 209                 while (ofst < bv->bv_len &&
 210                        n < nr_rep && nz < nrz) {
 211                         if (blkdev_report_zone(bdev, addr + ofst, &zones[nz]))
 212                                 nz++;
 213                         ofst += sizeof(struct blk_zone);
 214                         n++;
 215                 }
 216
 217                 kunmap_atomic(addr);
 218
 219                 if (n >= nr_rep || nz >= nrz)
 220                         break;
 221
 222         }
 223
 224         *nr_zones = nz;
 225 out:
 226         bio_for_each_segment_all(bv, bio, i)
 227                 __free_page(bv->bv_page);
 228         bio_put(bio);
 229
 230         return ret;
 231 }
 232 EXPORT_SYMBOL_GPL(blkdev_report_zones);
 233
 234 /**
 235  * blkdev_reset_zones - Reset zones write pointer
 236  * @bdev:       Target block device
 237  * @sector:     Start sector of the first zone to reset
 238  * @nr_sectors: Number of sectors, at least the length of one zone
 239  * @gfp_mask:   Memory allocation flags (for bio_alloc)
 240  *
 241  * Description:
 242  *    Reset the write pointer of the zones contained in the range
 243  *    @sector..@sector+@nr_sectors. Specifying the entire disk sector range
 244  *    is valid, but the specified range should not contain conventional zones.
 245  */
 246 int blkdev_reset_zones(struct block_device *bdev,
 247                        sector_t sector, sector_t nr_sectors,
 248                        gfp_t gfp_mask)
 249 {
 250         struct request_queue *q = bdev_get_queue(bdev);
 251         sector_t zone_sectors;
 252         sector_t end_sector = sector + nr_sectors;
 253         struct bio *bio;
 254         int ret;
 255
 256         if (!q)
 257                 return -ENXIO;
 258
 259         if (!blk_queue_is_zoned(q))
 260                 return -EOPNOTSUPP;
 261
 262         if (end_sector > bdev->bd_part->nr_sects)
 263                 /* Out of range */
 264                 return -EINVAL;
 265
 266         /* Check alignment (handle eventual smaller last zone) */
 267         zone_sectors = blk_queue_zone_sectors(q);
 268         if (sector & (zone_sectors - 1))
 269                 return -EINVAL;
 270
 271         if ((nr_sectors & (zone_sectors - 1)) &&
 272             end_sector != bdev->bd_part->nr_sects)
 273                 return -EINVAL;
 274
 275         while (sector < end_sector) {
 276
 277                 bio = bio_alloc(gfp_mask, 0);
 278                 bio->bi_iter.bi_sector = sector;
 279                 bio_set_dev(bio, bdev);
 280                 bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
 281
 282                 ret = submit_bio_wait(bio);
 283                 bio_put(bio);
 284
 285                 if (ret)
 286                         return ret;
 287
 288                 sector += zone_sectors;
 289
 290                 /* This may take a while, so be nice to others */
 291                 cond_resched();
 292
 293         }
 294
 295         return 0;
 296 }
 297 EXPORT_SYMBOL_GPL(blkdev_reset_zones);
 298
 299 /*
 300  * BLKREPORTZONE ioctl processing.
 301  * Called from blkdev_ioctl.
 302  */
 303 int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 304                               unsigned int cmd, unsigned long arg)
 305 {
 306         void __user *argp = (void __user *)arg;
 307         struct request_queue *q;
 308         struct blk_zone_report rep;
 309         struct blk_zone *zones;
 310         int ret;
 311
 312         if (!argp)
 313                 return -EINVAL;
 314
 315         q = bdev_get_queue(bdev);
 316         if (!q)
 317                 return -ENXIO;
 318
 319         if (!blk_queue_is_zoned(q))
 320                 return -ENOTTY;
 321
 322         if (!capable(CAP_SYS_ADMIN))
 323                 return -EACCES;
 324
 325         if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
 326                 return -EFAULT;
 327
 328         if (!rep.nr_zones)
 329                 return -EINVAL;
 330
 331         if (rep.nr_zones > INT_MAX / sizeof(struct blk_zone))
 332                 return -ERANGE;
 333
 334         zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
 335                                GFP_KERNEL | __GFP_ZERO);
 336         if (!zones)
 337                 return -ENOMEM;
 338
 339         ret = blkdev_report_zones(bdev, rep.sector,
 340                                   zones, &rep.nr_zones,
 341                                   GFP_KERNEL);
 342         if (ret)
 343                 goto out;
 344
 345         if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
 346                 ret = -EFAULT;
 347                 goto out;
 348         }
 349
 350         if (rep.nr_zones) {
 351                 if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
 352                                  sizeof(struct blk_zone) * rep.nr_zones))
 353                         ret = -EFAULT;
 354         }
 355
 356  out:
 357         kvfree(zones);
 358
 359         return ret;
 360 }
 361
 362 /*
 363  * BLKRESETZONE ioctl processing.
 364  * Called from blkdev_ioctl.
 365  */
 366 int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
 367                              unsigned int cmd, unsigned long arg)
 368 {
 369         void __user *argp = (void __user *)arg;
 370         struct request_queue *q;
 371         struct blk_zone_range zrange;
 372
 373         if (!argp)
 374                 return -EINVAL;
 375
 376         q = bdev_get_queue(bdev);
 377         if (!q)
 378                 return -ENXIO;
 379
 380         if (!blk_queue_is_zoned(q))
 381                 return -ENOTTY;
 382
 383         if (!capable(CAP_SYS_ADMIN))
 384                 return -EACCES;
 385
 386         if (!(mode & FMODE_WRITE))
 387                 return -EBADF;
 388
 389         if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
 390                 return -EFAULT;
 391
 392         return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
 393                                   GFP_KERNEL);
 394 }