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