block/parallels.c

   1 /*
   2  * Block driver for Parallels disk image format
   3  *
   4  * Copyright (c) 2007 Alex Beregszaszi
   5  * Copyright (c) 2015 Denis V. Lunev <den@openvz.org>
   6  *
   7  * This code was originally based on comparing different disk images created
   8  * by Parallels. Currently it is based on opened OpenVZ sources
   9  * available at
  10  *     http://git.openvz.org/?p=ploop;a=summary
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a copy
  13  * of this software and associated documentation files (the "Software"), to deal
  14  * in the Software without restriction, including without limitation the rights
  15  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  16  * copies of the Software, and to permit persons to whom the Software is
  17  * furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included in
  20  * all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  25  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  27  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  28  * THE SOFTWARE.
  29  */
  30
  31 #include "qemu/osdep.h"
  32 #include "qemu/error-report.h"
  33 #include "qapi/error.h"
  34 #include "block/block_int.h"
  35 #include "block/qdict.h"
  36 #include "sysemu/block-backend.h"
  37 #include "qemu/module.h"
  38 #include "qemu/option.h"
  39 #include "qapi/qmp/qdict.h"
  40 #include "qapi/qobject-input-visitor.h"
  41 #include "qapi/qapi-visit-block-core.h"
  42 #include "qemu/bswap.h"
  43 #include "qemu/bitmap.h"
  44 #include "qemu/memalign.h"
  45 #include "migration/blocker.h"
  46 #include "parallels.h"
  47
  48 /**************************************************************/
  49
  50 #define HEADER_MAGIC "WithoutFreeSpace"
  51 #define HEADER_MAGIC2 "WithouFreSpacExt"
  52 #define HEADER_VERSION 2
  53 #define HEADER_INUSE_MAGIC  (0x746F6E59)
  54 #define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
  55
  56 static QEnumLookup prealloc_mode_lookup = {
  57     .array = (const char *const[]) {
  58         "falloc",
  59         "truncate",
  60     },
  61     .size = PRL_PREALLOC_MODE__MAX
  62 };
  63
  64 #define PARALLELS_OPT_PREALLOC_MODE     "prealloc-mode"
  65 #define PARALLELS_OPT_PREALLOC_SIZE     "prealloc-size"
  66
  67 static QemuOptsList parallels_runtime_opts = {
  68     .name = "parallels",
  69     .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
  70     .desc = {
  71         {
  72             .name = PARALLELS_OPT_PREALLOC_SIZE,
  73             .type = QEMU_OPT_SIZE,
  74             .help = "Preallocation size on image expansion",
  75             .def_value_str = "128M",
  76         },
  77         {
  78             .name = PARALLELS_OPT_PREALLOC_MODE,
  79             .type = QEMU_OPT_STRING,
  80             .help = "Preallocation mode on image expansion "
  81                     "(allowed values: falloc, truncate)",
  82             .def_value_str = "falloc",
  83         },
  84         { /* end of list */ },
  85     },
  86 };
  87
  88 static QemuOptsList parallels_create_opts = {
  89     .name = "parallels-create-opts",
  90     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
  91     .desc = {
  92         {
  93             .name = BLOCK_OPT_SIZE,
  94             .type = QEMU_OPT_SIZE,
  95             .help = "Virtual disk size",
  96         },
  97         {
  98             .name = BLOCK_OPT_CLUSTER_SIZE,
  99             .type = QEMU_OPT_SIZE,
 100             .help = "Parallels image cluster size",
 101             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
 102         },
 103         { /* end of list */ }
 104     }
 105 };
 106
 107
 108 static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
 109 {
 110     return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
 111 }
 112
 113 static uint32_t bat_entry_off(uint32_t idx)
 114 {
 115     return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
 116 }
 117
 118 static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
 119 {
 120     uint32_t index, offset;
 121
 122     index = sector_num / s->tracks;
 123     offset = sector_num % s->tracks;
 124
 125     /* not allocated */
 126     if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
 127         return -1;
 128     }
 129     return bat2sect(s, index) + offset;
 130 }
 131
 132 static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
 133         int nb_sectors)
 134 {
 135     int ret = s->tracks - sector_num % s->tracks;
 136     return MIN(nb_sectors, ret);
 137 }
 138
 139 static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
 140                             int nb_sectors, int *pnum)
 141 {
 142     int64_t start_off = -2, prev_end_off = -2;
 143
 144     *pnum = 0;
 145     while (nb_sectors > 0 || start_off == -2) {
 146         int64_t offset = seek_to_sector(s, sector_num);
 147         int to_end;
 148
 149         if (start_off == -2) {
 150             start_off = offset;
 151             prev_end_off = offset;
 152         } else if (offset != prev_end_off) {
 153             break;
 154         }
 155
 156         to_end = cluster_remainder(s, sector_num, nb_sectors);
 157         nb_sectors -= to_end;
 158         sector_num += to_end;
 159         *pnum += to_end;
 160
 161         if (offset > 0) {
 162             prev_end_off += to_end;
 163         }
 164     }
 165     return start_off;
 166 }
 167
 168 static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
 169                                  int nb_sectors, int *pnum)
 170 {
 171     int ret = 0;
 172     BDRVParallelsState *s = bs->opaque;
 173     int64_t pos, space, idx, to_allocate, i, len;
 174
 175     pos = block_status(s, sector_num, nb_sectors, pnum);
 176     if (pos > 0) {
 177         return pos;
 178     }
 179
 180     idx = sector_num / s->tracks;
 181     to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
 182
 183     /* This function is called only by parallels_co_writev(), which will never
 184      * pass a sector_num at or beyond the end of the image (because the block
 185      * layer never passes such a sector_num to that function). Therefore, idx
 186      * is always below s->bat_size.
 187      * block_status() will limit *pnum so that sector_num + *pnum will not
 188      * exceed the image end. Therefore, idx + to_allocate cannot exceed
 189      * s->bat_size.
 190      * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
 191      * will always fit into a uint32_t. */
 192     assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
 193
 194     space = to_allocate * s->tracks;
 195     len = bdrv_getlength(bs->file->bs);
 196     if (len < 0) {
 197         return len;
 198     }
 199     if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
 200         space += s->prealloc_size;
 201         /*
 202          * We require the expanded size to read back as zero. If the
 203          * user permitted truncation, we try that; but if it fails, we
 204          * force the safer-but-slower fallocate.
 205          */
 206         if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
 207             ret = bdrv_truncate(bs->file,
 208                                 (s->data_end + space) << BDRV_SECTOR_BITS,
 209                                 false, PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE,
 210                                 NULL);
 211             if (ret == -ENOTSUP) {
 212                 s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
 213             }
 214         }
 215         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
 216             ret = bdrv_pwrite_zeroes(bs->file,
 217                                      s->data_end << BDRV_SECTOR_BITS,
 218                                      space << BDRV_SECTOR_BITS, 0);
 219         }
 220         if (ret < 0) {
 221             return ret;
 222         }
 223     }
 224
 225     /* Try to read from backing to fill empty clusters
 226      * FIXME: 1. previous write_zeroes may be redundant
 227      *        2. most of data we read from backing will be rewritten by
 228      *           parallels_co_writev. On aligned-to-cluster write we do not need
 229      *           this read at all.
 230      *        3. it would be good to combine write of data from backing and new
 231      *           data into one write call */
 232     if (bs->backing) {
 233         int64_t nb_cow_sectors = to_allocate * s->tracks;
 234         int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
 235         void *buf = qemu_blockalign(bs, nb_cow_bytes);
 236
 237         ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
 238                             nb_cow_bytes, buf, 0);
 239         if (ret < 0) {
 240             qemu_vfree(buf);
 241             return ret;
 242         }
 243
 244         ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
 245                               nb_cow_bytes, buf, 0);
 246         qemu_vfree(buf);
 247         if (ret < 0) {
 248             return ret;
 249         }
 250     }
 251
 252     for (i = 0; i < to_allocate; i++) {
 253         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
 254         s->data_end += s->tracks;
 255         bitmap_set(s->bat_dirty_bmap,
 256                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
 257     }
 258
 259     return bat2sect(s, idx) + sector_num % s->tracks;
 260 }
 261
 262
 263 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
 264 {
 265     BDRVParallelsState *s = bs->opaque;
 266     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
 267     unsigned long bit;
 268
 269     qemu_co_mutex_lock(&s->lock);
 270
 271     bit = find_first_bit(s->bat_dirty_bmap, size);
 272     while (bit < size) {
 273         uint32_t off = bit * s->bat_dirty_block;
 274         uint32_t to_write = s->bat_dirty_block;
 275         int ret;
 276
 277         if (off + to_write > s->header_size) {
 278             to_write = s->header_size - off;
 279         }
 280         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
 281                           to_write);
 282         if (ret < 0) {
 283             qemu_co_mutex_unlock(&s->lock);
 284             return ret;
 285         }
 286         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
 287     }
 288     bitmap_zero(s->bat_dirty_bmap, size);
 289
 290     qemu_co_mutex_unlock(&s->lock);
 291     return 0;
 292 }
 293
 294
 295 static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
 296                                                   bool want_zero,
 297                                                   int64_t offset,
 298                                                   int64_t bytes,
 299                                                   int64_t *pnum,
 300                                                   int64_t *map,
 301                                                   BlockDriverState **file)
 302 {
 303     BDRVParallelsState *s = bs->opaque;
 304     int count;
 305
 306     assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
 307     qemu_co_mutex_lock(&s->lock);
 308     offset = block_status(s, offset >> BDRV_SECTOR_BITS,
 309                           bytes >> BDRV_SECTOR_BITS, &count);
 310     qemu_co_mutex_unlock(&s->lock);
 311
 312     *pnum = count * BDRV_SECTOR_SIZE;
 313     if (offset < 0) {
 314         return 0;
 315     }
 316
 317     *map = offset * BDRV_SECTOR_SIZE;
 318     *file = bs->file->bs;
 319     return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 320 }
 321
 322 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
 323                                             int64_t sector_num, int nb_sectors,
 324                                             QEMUIOVector *qiov, int flags)
 325 {
 326     BDRVParallelsState *s = bs->opaque;
 327     uint64_t bytes_done = 0;
 328     QEMUIOVector hd_qiov;
 329     int ret = 0;
 330
 331     assert(!flags);
 332     qemu_iovec_init(&hd_qiov, qiov->niov);
 333
 334     while (nb_sectors > 0) {
 335         int64_t position;
 336         int n, nbytes;
 337
 338         qemu_co_mutex_lock(&s->lock);
 339         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
 340         qemu_co_mutex_unlock(&s->lock);
 341         if (position < 0) {
 342             ret = (int)position;
 343             break;
 344         }
 345
 346         nbytes = n << BDRV_SECTOR_BITS;
 347
 348         qemu_iovec_reset(&hd_qiov);
 349         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 350
 351         ret = bdrv_co_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
 352                               &hd_qiov, 0);
 353         if (ret < 0) {
 354             break;
 355         }
 356
 357         nb_sectors -= n;
 358         sector_num += n;
 359         bytes_done += nbytes;
 360     }
 361
 362     qemu_iovec_destroy(&hd_qiov);
 363     return ret;
 364 }
 365
 366 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
 367         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 368 {
 369     BDRVParallelsState *s = bs->opaque;
 370     uint64_t bytes_done = 0;
 371     QEMUIOVector hd_qiov;
 372     int ret = 0;
 373
 374     qemu_iovec_init(&hd_qiov, qiov->niov);
 375
 376     while (nb_sectors > 0) {
 377         int64_t position;
 378         int n, nbytes;
 379
 380         qemu_co_mutex_lock(&s->lock);
 381         position = block_status(s, sector_num, nb_sectors, &n);
 382         qemu_co_mutex_unlock(&s->lock);
 383
 384         nbytes = n << BDRV_SECTOR_BITS;
 385
 386         qemu_iovec_reset(&hd_qiov);
 387         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 388
 389         if (position < 0) {
 390             if (bs->backing) {
 391                 ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
 392                                      nbytes, &hd_qiov, 0);
 393                 if (ret < 0) {
 394                     break;
 395                 }
 396             } else {
 397                 qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
 398             }
 399         } else {
 400             ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
 401                                  &hd_qiov, 0);
 402             if (ret < 0) {
 403                 break;
 404             }
 405         }
 406
 407         nb_sectors -= n;
 408         sector_num += n;
 409         bytes_done += nbytes;
 410     }
 411
 412     qemu_iovec_destroy(&hd_qiov);
 413     return ret;
 414 }
 415
 416
 417 static int coroutine_fn parallels_co_check(BlockDriverState *bs,
 418                                            BdrvCheckResult *res,
 419                                            BdrvCheckMode fix)
 420 {
 421     BDRVParallelsState *s = bs->opaque;
 422     int64_t size, prev_off, high_off;
 423     int ret;
 424     uint32_t i;
 425     bool flush_bat = false;
 426
 427     size = bdrv_getlength(bs->file->bs);
 428     if (size < 0) {
 429         res->check_errors++;
 430         return size;
 431     }
 432
 433     qemu_co_mutex_lock(&s->lock);
 434     if (s->header_unclean) {
 435         fprintf(stderr, "%s image was not closed correctly\n",
 436                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
 437         res->corruptions++;
 438         if (fix & BDRV_FIX_ERRORS) {
 439             /* parallels_close will do the job right */
 440             res->corruptions_fixed++;
 441             s->header_unclean = false;
 442         }
 443     }
 444
 445     res->bfi.total_clusters = s->bat_size;
 446     res->bfi.compressed_clusters = 0; /* compression is not supported */
 447
 448     high_off = 0;
 449     prev_off = 0;
 450     for (i = 0; i < s->bat_size; i++) {
 451         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
 452         if (off == 0) {
 453             prev_off = 0;
 454             continue;
 455         }
 456
 457         /* cluster outside the image */
 458         if (off > size) {
 459             fprintf(stderr, "%s cluster %u is outside image\n",
 460                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
 461             res->corruptions++;
 462             if (fix & BDRV_FIX_ERRORS) {
 463                 prev_off = 0;
 464                 s->bat_bitmap[i] = 0;
 465                 res->corruptions_fixed++;
 466                 flush_bat = true;
 467                 continue;
 468             }
 469         }
 470
 471         res->bfi.allocated_clusters++;
 472         if (off > high_off) {
 473             high_off = off;
 474         }
 475
 476         if (prev_off != 0 && (prev_off + s->cluster_size) != off) {
 477             res->bfi.fragmented_clusters++;
 478         }
 479         prev_off = off;
 480     }
 481
 482     ret = 0;
 483     if (flush_bat) {
 484         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
 485         if (ret < 0) {
 486             res->check_errors++;
 487             goto out;
 488         }
 489     }
 490
 491     res->image_end_offset = high_off + s->cluster_size;
 492     if (size > res->image_end_offset) {
 493         int64_t count;
 494         count = DIV_ROUND_UP(size - res->image_end_offset, s->cluster_size);
 495         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
 496                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
 497                 size - res->image_end_offset);
 498         res->leaks += count;
 499         if (fix & BDRV_FIX_LEAKS) {
 500             Error *local_err = NULL;
 501
 502             /*
 503              * In order to really repair the image, we must shrink it.
 504              * That means we have to pass exact=true.
 505              */
 506             ret = bdrv_truncate(bs->file, res->image_end_offset, true,
 507                                 PREALLOC_MODE_OFF, 0, &local_err);
 508             if (ret < 0) {
 509                 error_report_err(local_err);
 510                 res->check_errors++;
 511                 goto out;
 512             }
 513             res->leaks_fixed += count;
 514         }
 515     }
 516
 517 out:
 518     qemu_co_mutex_unlock(&s->lock);
 519     return ret;
 520 }
 521
 522
 523 static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts,
 524                                             Error **errp)
 525 {
 526     BlockdevCreateOptionsParallels *parallels_opts;
 527     BlockDriverState *bs;
 528     BlockBackend *blk;
 529     int64_t total_size, cl_size;
 530     uint32_t bat_entries, bat_sectors;
 531     ParallelsHeader header;
 532     uint8_t tmp[BDRV_SECTOR_SIZE];
 533     int ret;
 534
 535     assert(opts->driver == BLOCKDEV_DRIVER_PARALLELS);
 536     parallels_opts = &opts->u.parallels;
 537
 538     /* Sanity checks */
 539     total_size = parallels_opts->size;
 540
 541     if (parallels_opts->has_cluster_size) {
 542         cl_size = parallels_opts->cluster_size;
 543     } else {
 544         cl_size = DEFAULT_CLUSTER_SIZE;
 545     }
 546
 547     /* XXX What is the real limit here? This is an insanely large maximum. */
 548     if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
 549         error_setg(errp, "Cluster size is too large");
 550         return -EINVAL;
 551     }
 552     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
 553         error_setg(errp, "Image size is too large for this cluster size");
 554         return -E2BIG;
 555     }
 556
 557     if (!QEMU_IS_ALIGNED(total_size, BDRV_SECTOR_SIZE)) {
 558         error_setg(errp, "Image size must be a multiple of 512 bytes");
 559         return -EINVAL;
 560     }
 561
 562     if (!QEMU_IS_ALIGNED(cl_size, BDRV_SECTOR_SIZE)) {
 563         error_setg(errp, "Cluster size must be a multiple of 512 bytes");
 564         return -EINVAL;
 565     }
 566
 567     /* Create BlockBackend to write to the image */
 568     bs = bdrv_open_blockdev_ref(parallels_opts->file, errp);
 569     if (bs == NULL) {
 570         return -EIO;
 571     }
 572
 573     blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
 574                           errp);
 575     if (!blk) {
 576         ret = -EPERM;
 577         goto out;
 578     }
 579     blk_set_allow_write_beyond_eof(blk, true);
 580
 581     /* Create image format */
 582     bat_entries = DIV_ROUND_UP(total_size, cl_size);
 583     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
 584     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
 585
 586     memset(&header, 0, sizeof(header));
 587     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
 588     header.version = cpu_to_le32(HEADER_VERSION);
 589     /* don't care much about geometry, it is not used on image level */
 590     header.heads = cpu_to_le32(HEADS_NUMBER);
 591     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
 592                                    / HEADS_NUMBER / SEC_IN_CYL);
 593     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
 594     header.bat_entries = cpu_to_le32(bat_entries);
 595     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
 596     header.data_off = cpu_to_le32(bat_sectors);
 597
 598     /* write all the data */
 599     memset(tmp, 0, sizeof(tmp));
 600     memcpy(tmp, &header, sizeof(header));
 601
 602     ret = blk_pwrite(blk, 0, tmp, BDRV_SECTOR_SIZE, 0);
 603     if (ret < 0) {
 604         goto exit;
 605     }
 606     ret = blk_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
 607                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
 608     if (ret < 0) {
 609         goto exit;
 610     }
 611
 612     ret = 0;
 613 out:
 614     blk_unref(blk);
 615     bdrv_unref(bs);
 616     return ret;
 617
 618 exit:
 619     error_setg_errno(errp, -ret, "Failed to create Parallels image");
 620     goto out;
 621 }
 622
 623 static int coroutine_fn parallels_co_create_opts(BlockDriver *drv,
 624                                                  const char *filename,
 625                                                  QemuOpts *opts,
 626                                                  Error **errp)
 627 {
 628     BlockdevCreateOptions *create_options = NULL;
 629     BlockDriverState *bs = NULL;
 630     QDict *qdict;
 631     Visitor *v;
 632     int ret;
 633
 634     static const QDictRenames opt_renames[] = {
 635         { BLOCK_OPT_CLUSTER_SIZE,       "cluster-size" },
 636         { NULL, NULL },
 637     };
 638
 639     /* Parse options and convert legacy syntax */
 640     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
 641                                         true);
 642
 643     if (!qdict_rename_keys(qdict, opt_renames, errp)) {
 644         ret = -EINVAL;
 645         goto done;
 646     }
 647
 648     /* Create and open the file (protocol layer) */
 649     ret = bdrv_create_file(filename, opts, errp);
 650     if (ret < 0) {
 651         goto done;
 652     }
 653
 654     bs = bdrv_open(filename, NULL, NULL,
 655                    BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
 656     if (bs == NULL) {
 657         ret = -EIO;
 658         goto done;
 659     }
 660
 661     /* Now get the QAPI type BlockdevCreateOptions */
 662     qdict_put_str(qdict, "driver", "parallels");
 663     qdict_put_str(qdict, "file", bs->node_name);
 664
 665     v = qobject_input_visitor_new_flat_confused(qdict, errp);
 666     if (!v) {
 667         ret = -EINVAL;
 668         goto done;
 669     }
 670
 671     visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
 672     visit_free(v);
 673     if (!create_options) {
 674         ret = -EINVAL;
 675         goto done;
 676     }
 677
 678     /* Silently round up sizes */
 679     create_options->u.parallels.size =
 680         ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
 681     create_options->u.parallels.cluster_size =
 682         ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
 683
 684     /* Create the Parallels image (format layer) */
 685     ret = parallels_co_create(create_options, errp);
 686     if (ret < 0) {
 687         goto done;
 688     }
 689     ret = 0;
 690
 691 done:
 692     qobject_unref(qdict);
 693     bdrv_unref(bs);
 694     qapi_free_BlockdevCreateOptions(create_options);
 695     return ret;
 696 }
 697
 698
 699 static int parallels_probe(const uint8_t *buf, int buf_size,
 700                            const char *filename)
 701 {
 702     const ParallelsHeader *ph = (const void *)buf;
 703
 704     if (buf_size < sizeof(ParallelsHeader)) {
 705         return 0;
 706     }
 707
 708     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
 709            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
 710            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
 711         return 100;
 712     }
 713
 714     return 0;
 715 }
 716
 717 static int parallels_update_header(BlockDriverState *bs)
 718 {
 719     BDRVParallelsState *s = bs->opaque;
 720     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
 721                         sizeof(ParallelsHeader));
 722
 723     if (size > s->header_size) {
 724         size = s->header_size;
 725     }
 726     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
 727 }
 728
 729 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
 730                           Error **errp)
 731 {
 732     BDRVParallelsState *s = bs->opaque;
 733     ParallelsHeader ph;
 734     int ret, size, i;
 735     QemuOpts *opts = NULL;
 736     Error *local_err = NULL;
 737     char *buf;
 738
 739     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
 740                                BDRV_CHILD_IMAGE, false, errp);
 741     if (!bs->file) {
 742         return -EINVAL;
 743     }
 744
 745     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
 746     if (ret < 0) {
 747         goto fail;
 748     }
 749
 750     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
 751
 752     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
 753         goto fail_format;
 754     }
 755     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
 756         s->off_multiplier = 1;
 757         bs->total_sectors = 0xffffffff & bs->total_sectors;
 758     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
 759         s->off_multiplier = le32_to_cpu(ph.tracks);
 760     } else {
 761         goto fail_format;
 762     }
 763
 764     s->tracks = le32_to_cpu(ph.tracks);
 765     if (s->tracks == 0) {
 766         error_setg(errp, "Invalid image: Zero sectors per track");
 767         ret = -EINVAL;
 768         goto fail;
 769     }
 770     if (s->tracks > INT32_MAX/513) {
 771         error_setg(errp, "Invalid image: Too big cluster");
 772         ret = -EFBIG;
 773         goto fail;
 774     }
 775     s->cluster_size = s->tracks << BDRV_SECTOR_BITS;
 776
 777     s->bat_size = le32_to_cpu(ph.bat_entries);
 778     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
 779         error_setg(errp, "Catalog too large");
 780         ret = -EFBIG;
 781         goto fail;
 782     }
 783
 784     size = bat_entry_off(s->bat_size);
 785     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
 786     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
 787     if (s->header == NULL) {
 788         ret = -ENOMEM;
 789         goto fail;
 790     }
 791     s->data_end = le32_to_cpu(ph.data_off);
 792     if (s->data_end == 0) {
 793         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
 794     }
 795     if (s->data_end < s->header_size) {
 796         /* there is not enough unused space to fit to block align between BAT
 797            and actual data. We can't avoid read-modify-write... */
 798         s->header_size = size;
 799     }
 800
 801     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
 802     if (ret < 0) {
 803         goto fail;
 804     }
 805     s->bat_bitmap = (uint32_t *)(s->header + 1);
 806
 807     for (i = 0; i < s->bat_size; i++) {
 808         int64_t off = bat2sect(s, i);
 809         if (off >= s->data_end) {
 810             s->data_end = off + s->tracks;
 811         }
 812     }
 813
 814     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
 815         /* Image was not closed correctly. The check is mandatory */
 816         s->header_unclean = true;
 817         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
 818             error_setg(errp, "parallels: Image was not closed correctly; "
 819                        "cannot be opened read/write");
 820             ret = -EACCES;
 821             goto fail;
 822         }
 823     }
 824
 825     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, errp);
 826     if (!opts) {
 827         goto fail_options;
 828     }
 829
 830     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 831         goto fail_options;
 832     }
 833
 834     s->prealloc_size =
 835         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
 836     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
 837     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
 838     /* prealloc_mode can be downgraded later during allocate_clusters */
 839     s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
 840                                        PRL_PREALLOC_MODE_FALLOCATE,
 841                                        &local_err);
 842     g_free(buf);
 843     if (local_err != NULL) {
 844         error_propagate(errp, local_err);
 845         goto fail_options;
 846     }
 847
 848     if (ph.ext_off) {
 849         if (flags & BDRV_O_RDWR) {
 850             /*
 851              * It's unsafe to open image RW if there is an extension (as we
 852              * don't support it). But parallels driver in QEMU historically
 853              * ignores the extension, so print warning and don't care.
 854              */
 855             warn_report("Format Extension ignored in RW mode");
 856         } else {
 857             ret = parallels_read_format_extension(
 858                     bs, le64_to_cpu(ph.ext_off) << BDRV_SECTOR_BITS, errp);
 859             if (ret < 0) {
 860                 goto fail;
 861             }
 862         }
 863     }
 864
 865     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
 866         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
 867         ret = parallels_update_header(bs);
 868         if (ret < 0) {
 869             goto fail;
 870         }
 871     }
 872
 873     s->bat_dirty_block = 4 * qemu_real_host_page_size();
 874     s->bat_dirty_bmap =
 875         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
 876
 877     /* Disable migration until bdrv_activate method is added */
 878     error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
 879                "does not support live migration",
 880                bdrv_get_device_or_node_name(bs));
 881     ret = migrate_add_blocker(s->migration_blocker, errp);
 882     if (ret < 0) {
 883         error_free(s->migration_blocker);
 884         goto fail;
 885     }
 886     qemu_co_mutex_init(&s->lock);
 887     return 0;
 888
 889 fail_format:
 890     error_setg(errp, "Image not in Parallels format");
 891 fail_options:
 892     ret = -EINVAL;
 893 fail:
 894     qemu_vfree(s->header);
 895     return ret;
 896 }
 897
 898
 899 static void parallels_close(BlockDriverState *bs)
 900 {
 901     BDRVParallelsState *s = bs->opaque;
 902
 903     if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
 904         s->header->inuse = 0;
 905         parallels_update_header(bs);
 906
 907         /* errors are ignored, so we might as well pass exact=true */
 908         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, true,
 909                       PREALLOC_MODE_OFF, 0, NULL);
 910     }
 911
 912     g_free(s->bat_dirty_bmap);
 913     qemu_vfree(s->header);
 914
 915     migrate_del_blocker(s->migration_blocker);
 916     error_free(s->migration_blocker);
 917 }
 918
 919 static BlockDriver bdrv_parallels = {
 920     .format_name        = "parallels",
 921     .instance_size      = sizeof(BDRVParallelsState),
 922     .bdrv_probe         = parallels_probe,
 923     .bdrv_open          = parallels_open,
 924     .bdrv_close         = parallels_close,
 925     .bdrv_child_perm          = bdrv_default_perms,
 926     .bdrv_co_block_status     = parallels_co_block_status,
 927     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
 928     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
 929     .bdrv_co_readv  = parallels_co_readv,
 930     .bdrv_co_writev = parallels_co_writev,
 931     .is_format      = true,
 932     .supports_backing = true,
 933     .bdrv_co_create      = parallels_co_create,
 934     .bdrv_co_create_opts = parallels_co_create_opts,
 935     .bdrv_co_check  = parallels_co_check,
 936     .create_opts    = &parallels_create_opts,
 937 };
 938
 939 static void bdrv_parallels_init(void)
 940 {
 941     bdrv_register(&bdrv_parallels);
 942 }
 943
 944 block_init(bdrv_parallels_init);