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 #include "qemu/osdep.h"
  31 #include "qapi/error.h"
  32 #include "qemu-common.h"
  33 #include "block/block_int.h"
  34 #include "sysemu/block-backend.h"
  35 #include "qemu/module.h"
  36 #include "qemu/bswap.h"
  37 #include "qemu/bitmap.h"
  38 #include "qapi/util.h"
  39
  40 /**************************************************************/
  41
  42 #define HEADER_MAGIC "WithoutFreeSpace"
  43 #define HEADER_MAGIC2 "WithouFreSpacExt"
  44 #define HEADER_VERSION 2
  45 #define HEADER_INUSE_MAGIC  (0x746F6E59)
  46 #define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
  47
  48 #define DEFAULT_CLUSTER_SIZE 1048576        /* 1 MiB */
  49
  50
  51 // always little-endian
  52 typedef struct ParallelsHeader {
  53     char magic[16]; // "WithoutFreeSpace"
  54     uint32_t version;
  55     uint32_t heads;
  56     uint32_t cylinders;
  57     uint32_t tracks;
  58     uint32_t bat_entries;
  59     uint64_t nb_sectors;
  60     uint32_t inuse;
  61     uint32_t data_off;
  62     char padding[12];
  63 } QEMU_PACKED ParallelsHeader;
  64
  65
  66 typedef enum ParallelsPreallocMode {
  67     PRL_PREALLOC_MODE_FALLOCATE = 0,
  68     PRL_PREALLOC_MODE_TRUNCATE = 1,
  69     PRL_PREALLOC_MODE__MAX = 2,
  70 } ParallelsPreallocMode;
  71
  72 static const char *prealloc_mode_lookup[] = {
  73     "falloc",
  74     "truncate",
  75     NULL,
  76 };
  77
  78
  79 typedef struct BDRVParallelsState {
  80     /** Locking is conservative, the lock protects
  81      *   - image file extending (truncate, fallocate)
  82      *   - any access to block allocation table
  83      */
  84     CoMutex lock;
  85
  86     ParallelsHeader *header;
  87     uint32_t header_size;
  88     bool header_unclean;
  89
  90     unsigned long *bat_dirty_bmap;
  91     unsigned int  bat_dirty_block;
  92
  93     uint32_t *bat_bitmap;
  94     unsigned int bat_size;
  95
  96     int64_t  data_end;
  97     uint64_t prealloc_size;
  98     ParallelsPreallocMode prealloc_mode;
  99
 100     unsigned int tracks;
 101
 102     unsigned int off_multiplier;
 103 } BDRVParallelsState;
 104
 105
 106 #define PARALLELS_OPT_PREALLOC_MODE     "prealloc-mode"
 107 #define PARALLELS_OPT_PREALLOC_SIZE     "prealloc-size"
 108
 109 static QemuOptsList parallels_runtime_opts = {
 110     .name = "parallels",
 111     .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
 112     .desc = {
 113         {
 114             .name = PARALLELS_OPT_PREALLOC_SIZE,
 115             .type = QEMU_OPT_SIZE,
 116             .help = "Preallocation size on image expansion",
 117             .def_value_str = "128M",
 118         },
 119         {
 120             .name = PARALLELS_OPT_PREALLOC_MODE,
 121             .type = QEMU_OPT_STRING,
 122             .help = "Preallocation mode on image expansion "
 123                     "(allowed values: falloc, truncate)",
 124             .def_value_str = "falloc",
 125         },
 126         { /* end of list */ },
 127     },
 128 };
 129
 130
 131 static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
 132 {
 133     return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
 134 }
 135
 136 static uint32_t bat_entry_off(uint32_t idx)
 137 {
 138     return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
 139 }
 140
 141 static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
 142 {
 143     uint32_t index, offset;
 144
 145     index = sector_num / s->tracks;
 146     offset = sector_num % s->tracks;
 147
 148     /* not allocated */
 149     if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
 150         return -1;
 151     }
 152     return bat2sect(s, index) + offset;
 153 }
 154
 155 static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
 156         int nb_sectors)
 157 {
 158     int ret = s->tracks - sector_num % s->tracks;
 159     return MIN(nb_sectors, ret);
 160 }
 161
 162 static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
 163                             int nb_sectors, int *pnum)
 164 {
 165     int64_t start_off = -2, prev_end_off = -2;
 166
 167     *pnum = 0;
 168     while (nb_sectors > 0 || start_off == -2) {
 169         int64_t offset = seek_to_sector(s, sector_num);
 170         int to_end;
 171
 172         if (start_off == -2) {
 173             start_off = offset;
 174             prev_end_off = offset;
 175         } else if (offset != prev_end_off) {
 176             break;
 177         }
 178
 179         to_end = cluster_remainder(s, sector_num, nb_sectors);
 180         nb_sectors -= to_end;
 181         sector_num += to_end;
 182         *pnum += to_end;
 183
 184         if (offset > 0) {
 185             prev_end_off += to_end;
 186         }
 187     }
 188     return start_off;
 189 }
 190
 191 static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
 192                                  int nb_sectors, int *pnum)
 193 {
 194     BDRVParallelsState *s = bs->opaque;
 195     int64_t pos, space, idx, to_allocate, i;
 196
 197     pos = block_status(s, sector_num, nb_sectors, pnum);
 198     if (pos > 0) {
 199         return pos;
 200     }
 201
 202     idx = sector_num / s->tracks;
 203     to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
 204
 205     /* This function is called only by parallels_co_writev(), which will never
 206      * pass a sector_num at or beyond the end of the image (because the block
 207      * layer never passes such a sector_num to that function). Therefore, idx
 208      * is always below s->bat_size.
 209      * block_status() will limit *pnum so that sector_num + *pnum will not
 210      * exceed the image end. Therefore, idx + to_allocate cannot exceed
 211      * s->bat_size.
 212      * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
 213      * will always fit into a uint32_t. */
 214     assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
 215
 216     space = to_allocate * s->tracks;
 217     if (s->data_end + space > bdrv_getlength(bs->file->bs) >> BDRV_SECTOR_BITS) {
 218         int ret;
 219         space += s->prealloc_size;
 220         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
 221             ret = bdrv_pwrite_zeroes(bs->file,
 222                                      s->data_end << BDRV_SECTOR_BITS,
 223                                      space << BDRV_SECTOR_BITS, 0);
 224         } else {
 225             ret = bdrv_truncate(bs->file,
 226                                 (s->data_end + space) << BDRV_SECTOR_BITS);
 227         }
 228         if (ret < 0) {
 229             return ret;
 230         }
 231     }
 232
 233     for (i = 0; i < to_allocate; i++) {
 234         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
 235         s->data_end += s->tracks;
 236         bitmap_set(s->bat_dirty_bmap,
 237                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
 238     }
 239
 240     return bat2sect(s, idx) + sector_num % s->tracks;
 241 }
 242
 243
 244 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
 245 {
 246     BDRVParallelsState *s = bs->opaque;
 247     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
 248     unsigned long bit;
 249
 250     qemu_co_mutex_lock(&s->lock);
 251
 252     bit = find_first_bit(s->bat_dirty_bmap, size);
 253     while (bit < size) {
 254         uint32_t off = bit * s->bat_dirty_block;
 255         uint32_t to_write = s->bat_dirty_block;
 256         int ret;
 257
 258         if (off + to_write > s->header_size) {
 259             to_write = s->header_size - off;
 260         }
 261         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
 262                           to_write);
 263         if (ret < 0) {
 264             qemu_co_mutex_unlock(&s->lock);
 265             return ret;
 266         }
 267         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
 268     }
 269     bitmap_zero(s->bat_dirty_bmap, size);
 270
 271     qemu_co_mutex_unlock(&s->lock);
 272     return 0;
 273 }
 274
 275
 276 static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
 277         int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 278 {
 279     BDRVParallelsState *s = bs->opaque;
 280     int64_t offset;
 281
 282     qemu_co_mutex_lock(&s->lock);
 283     offset = block_status(s, sector_num, nb_sectors, pnum);
 284     qemu_co_mutex_unlock(&s->lock);
 285
 286     if (offset < 0) {
 287         return 0;
 288     }
 289
 290     *file = bs->file->bs;
 291     return (offset << BDRV_SECTOR_BITS) |
 292         BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 293 }
 294
 295 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
 296         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 297 {
 298     BDRVParallelsState *s = bs->opaque;
 299     uint64_t bytes_done = 0;
 300     QEMUIOVector hd_qiov;
 301     int ret = 0;
 302
 303     qemu_iovec_init(&hd_qiov, qiov->niov);
 304
 305     while (nb_sectors > 0) {
 306         int64_t position;
 307         int n, nbytes;
 308
 309         qemu_co_mutex_lock(&s->lock);
 310         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
 311         qemu_co_mutex_unlock(&s->lock);
 312         if (position < 0) {
 313             ret = (int)position;
 314             break;
 315         }
 316
 317         nbytes = n << BDRV_SECTOR_BITS;
 318
 319         qemu_iovec_reset(&hd_qiov);
 320         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 321
 322         ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
 323         if (ret < 0) {
 324             break;
 325         }
 326
 327         nb_sectors -= n;
 328         sector_num += n;
 329         bytes_done += nbytes;
 330     }
 331
 332     qemu_iovec_destroy(&hd_qiov);
 333     return ret;
 334 }
 335
 336 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
 337         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 338 {
 339     BDRVParallelsState *s = bs->opaque;
 340     uint64_t bytes_done = 0;
 341     QEMUIOVector hd_qiov;
 342     int ret = 0;
 343
 344     qemu_iovec_init(&hd_qiov, qiov->niov);
 345
 346     while (nb_sectors > 0) {
 347         int64_t position;
 348         int n, nbytes;
 349
 350         qemu_co_mutex_lock(&s->lock);
 351         position = block_status(s, sector_num, nb_sectors, &n);
 352         qemu_co_mutex_unlock(&s->lock);
 353
 354         nbytes = n << BDRV_SECTOR_BITS;
 355
 356         if (position < 0) {
 357             qemu_iovec_memset(qiov, bytes_done, 0, nbytes);
 358         } else {
 359             qemu_iovec_reset(&hd_qiov);
 360             qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 361
 362             ret = bdrv_co_readv(bs->file, position, n, &hd_qiov);
 363             if (ret < 0) {
 364                 break;
 365             }
 366         }
 367
 368         nb_sectors -= n;
 369         sector_num += n;
 370         bytes_done += nbytes;
 371     }
 372
 373     qemu_iovec_destroy(&hd_qiov);
 374     return ret;
 375 }
 376
 377
 378 static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
 379                            BdrvCheckMode fix)
 380 {
 381     BDRVParallelsState *s = bs->opaque;
 382     int64_t size, prev_off, high_off;
 383     int ret;
 384     uint32_t i;
 385     bool flush_bat = false;
 386     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
 387
 388     size = bdrv_getlength(bs->file->bs);
 389     if (size < 0) {
 390         res->check_errors++;
 391         return size;
 392     }
 393
 394     if (s->header_unclean) {
 395         fprintf(stderr, "%s image was not closed correctly\n",
 396                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
 397         res->corruptions++;
 398         if (fix & BDRV_FIX_ERRORS) {
 399             /* parallels_close will do the job right */
 400             res->corruptions_fixed++;
 401             s->header_unclean = false;
 402         }
 403     }
 404
 405     res->bfi.total_clusters = s->bat_size;
 406     res->bfi.compressed_clusters = 0; /* compression is not supported */
 407
 408     high_off = 0;
 409     prev_off = 0;
 410     for (i = 0; i < s->bat_size; i++) {
 411         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
 412         if (off == 0) {
 413             prev_off = 0;
 414             continue;
 415         }
 416
 417         /* cluster outside the image */
 418         if (off > size) {
 419             fprintf(stderr, "%s cluster %u is outside image\n",
 420                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
 421             res->corruptions++;
 422             if (fix & BDRV_FIX_ERRORS) {
 423                 prev_off = 0;
 424                 s->bat_bitmap[i] = 0;
 425                 res->corruptions_fixed++;
 426                 flush_bat = true;
 427                 continue;
 428             }
 429         }
 430
 431         res->bfi.allocated_clusters++;
 432         if (off > high_off) {
 433             high_off = off;
 434         }
 435
 436         if (prev_off != 0 && (prev_off + cluster_size) != off) {
 437             res->bfi.fragmented_clusters++;
 438         }
 439         prev_off = off;
 440     }
 441
 442     if (flush_bat) {
 443         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
 444         if (ret < 0) {
 445             res->check_errors++;
 446             return ret;
 447         }
 448     }
 449
 450     res->image_end_offset = high_off + cluster_size;
 451     if (size > res->image_end_offset) {
 452         int64_t count;
 453         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
 454         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
 455                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
 456                 size - res->image_end_offset);
 457         res->leaks += count;
 458         if (fix & BDRV_FIX_LEAKS) {
 459             ret = bdrv_truncate(bs->file, res->image_end_offset);
 460             if (ret < 0) {
 461                 res->check_errors++;
 462                 return ret;
 463             }
 464             res->leaks_fixed += count;
 465         }
 466     }
 467
 468     return 0;
 469 }
 470
 471
 472 static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
 473 {
 474     int64_t total_size, cl_size;
 475     uint8_t tmp[BDRV_SECTOR_SIZE];
 476     Error *local_err = NULL;
 477     BlockBackend *file;
 478     uint32_t bat_entries, bat_sectors;
 479     ParallelsHeader header;
 480     int ret;
 481
 482     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 483                           BDRV_SECTOR_SIZE);
 484     cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
 485                           DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
 486     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
 487         error_propagate(errp, local_err);
 488         return -E2BIG;
 489     }
 490
 491     ret = bdrv_create_file(filename, opts, &local_err);
 492     if (ret < 0) {
 493         error_propagate(errp, local_err);
 494         return ret;
 495     }
 496
 497     file = blk_new_open(filename, NULL, NULL,
 498                         BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
 499                         &local_err);
 500     if (file == NULL) {
 501         error_propagate(errp, local_err);
 502         return -EIO;
 503     }
 504
 505     blk_set_allow_write_beyond_eof(file, true);
 506
 507     ret = blk_truncate(file, 0);
 508     if (ret < 0) {
 509         goto exit;
 510     }
 511
 512     bat_entries = DIV_ROUND_UP(total_size, cl_size);
 513     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
 514     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
 515
 516     memset(&header, 0, sizeof(header));
 517     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
 518     header.version = cpu_to_le32(HEADER_VERSION);
 519     /* don't care much about geometry, it is not used on image level */
 520     header.heads = cpu_to_le32(16);
 521     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE / 16 / 32);
 522     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
 523     header.bat_entries = cpu_to_le32(bat_entries);
 524     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
 525     header.data_off = cpu_to_le32(bat_sectors);
 526
 527     /* write all the data */
 528     memset(tmp, 0, sizeof(tmp));
 529     memcpy(tmp, &header, sizeof(header));
 530
 531     ret = blk_pwrite(file, 0, tmp, BDRV_SECTOR_SIZE, 0);
 532     if (ret < 0) {
 533         goto exit;
 534     }
 535     ret = blk_pwrite_zeroes(file, BDRV_SECTOR_SIZE,
 536                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
 537     if (ret < 0) {
 538         goto exit;
 539     }
 540     ret = 0;
 541
 542 done:
 543     blk_unref(file);
 544     return ret;
 545
 546 exit:
 547     error_setg_errno(errp, -ret, "Failed to create Parallels image");
 548     goto done;
 549 }
 550
 551
 552 static int parallels_probe(const uint8_t *buf, int buf_size,
 553                            const char *filename)
 554 {
 555     const ParallelsHeader *ph = (const void *)buf;
 556
 557     if (buf_size < sizeof(ParallelsHeader)) {
 558         return 0;
 559     }
 560
 561     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
 562            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
 563            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
 564         return 100;
 565     }
 566
 567     return 0;
 568 }
 569
 570 static int parallels_update_header(BlockDriverState *bs)
 571 {
 572     BDRVParallelsState *s = bs->opaque;
 573     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
 574                         sizeof(ParallelsHeader));
 575
 576     if (size > s->header_size) {
 577         size = s->header_size;
 578     }
 579     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
 580 }
 581
 582 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
 583                           Error **errp)
 584 {
 585     BDRVParallelsState *s = bs->opaque;
 586     ParallelsHeader ph;
 587     int ret, size, i;
 588     QemuOpts *opts = NULL;
 589     Error *local_err = NULL;
 590     char *buf;
 591
 592     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
 593                                false, errp);
 594     if (!bs->file) {
 595         return -EINVAL;
 596     }
 597
 598     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
 599     if (ret < 0) {
 600         goto fail;
 601     }
 602
 603     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
 604
 605     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
 606         goto fail_format;
 607     }
 608     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
 609         s->off_multiplier = 1;
 610         bs->total_sectors = 0xffffffff & bs->total_sectors;
 611     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
 612         s->off_multiplier = le32_to_cpu(ph.tracks);
 613     } else {
 614         goto fail_format;
 615     }
 616
 617     s->tracks = le32_to_cpu(ph.tracks);
 618     if (s->tracks == 0) {
 619         error_setg(errp, "Invalid image: Zero sectors per track");
 620         ret = -EINVAL;
 621         goto fail;
 622     }
 623     if (s->tracks > INT32_MAX/513) {
 624         error_setg(errp, "Invalid image: Too big cluster");
 625         ret = -EFBIG;
 626         goto fail;
 627     }
 628
 629     s->bat_size = le32_to_cpu(ph.bat_entries);
 630     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
 631         error_setg(errp, "Catalog too large");
 632         ret = -EFBIG;
 633         goto fail;
 634     }
 635
 636     size = bat_entry_off(s->bat_size);
 637     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
 638     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
 639     if (s->header == NULL) {
 640         ret = -ENOMEM;
 641         goto fail;
 642     }
 643     s->data_end = le32_to_cpu(ph.data_off);
 644     if (s->data_end == 0) {
 645         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
 646     }
 647     if (s->data_end < s->header_size) {
 648         /* there is not enough unused space to fit to block align between BAT
 649            and actual data. We can't avoid read-modify-write... */
 650         s->header_size = size;
 651     }
 652
 653     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
 654     if (ret < 0) {
 655         goto fail;
 656     }
 657     s->bat_bitmap = (uint32_t *)(s->header + 1);
 658
 659     for (i = 0; i < s->bat_size; i++) {
 660         int64_t off = bat2sect(s, i);
 661         if (off >= s->data_end) {
 662             s->data_end = off + s->tracks;
 663         }
 664     }
 665
 666     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
 667         /* Image was not closed correctly. The check is mandatory */
 668         s->header_unclean = true;
 669         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
 670             error_setg(errp, "parallels: Image was not closed correctly; "
 671                        "cannot be opened read/write");
 672             ret = -EACCES;
 673             goto fail;
 674         }
 675     }
 676
 677     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
 678     if (local_err != NULL) {
 679         goto fail_options;
 680     }
 681
 682     qemu_opts_absorb_qdict(opts, options, &local_err);
 683     if (local_err != NULL) {
 684         goto fail_options;
 685     }
 686
 687     s->prealloc_size =
 688         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
 689     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
 690     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
 691     s->prealloc_mode = qapi_enum_parse(prealloc_mode_lookup, buf,
 692             PRL_PREALLOC_MODE__MAX, PRL_PREALLOC_MODE_FALLOCATE, &local_err);
 693     g_free(buf);
 694     if (local_err != NULL) {
 695         goto fail_options;
 696     }
 697
 698     if (!(flags & BDRV_O_RESIZE) || !bdrv_has_zero_init(bs->file->bs) ||
 699             bdrv_truncate(bs->file, bdrv_getlength(bs->file->bs)) != 0) {
 700         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
 701     }
 702
 703     if (flags & BDRV_O_RDWR) {
 704         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
 705         ret = parallels_update_header(bs);
 706         if (ret < 0) {
 707             goto fail;
 708         }
 709     }
 710
 711     s->bat_dirty_block = 4 * getpagesize();
 712     s->bat_dirty_bmap =
 713         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
 714
 715     qemu_co_mutex_init(&s->lock);
 716     return 0;
 717
 718 fail_format:
 719     error_setg(errp, "Image not in Parallels format");
 720     ret = -EINVAL;
 721 fail:
 722     qemu_vfree(s->header);
 723     return ret;
 724
 725 fail_options:
 726     error_propagate(errp, local_err);
 727     ret = -EINVAL;
 728     goto fail;
 729 }
 730
 731
 732 static void parallels_close(BlockDriverState *bs)
 733 {
 734     BDRVParallelsState *s = bs->opaque;
 735
 736     if (bs->open_flags & BDRV_O_RDWR) {
 737         s->header->inuse = 0;
 738         parallels_update_header(bs);
 739     }
 740
 741     if (bs->open_flags & BDRV_O_RDWR) {
 742         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS);
 743     }
 744
 745     g_free(s->bat_dirty_bmap);
 746     qemu_vfree(s->header);
 747 }
 748
 749 static QemuOptsList parallels_create_opts = {
 750     .name = "parallels-create-opts",
 751     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
 752     .desc = {
 753         {
 754             .name = BLOCK_OPT_SIZE,
 755             .type = QEMU_OPT_SIZE,
 756             .help = "Virtual disk size",
 757         },
 758         {
 759             .name = BLOCK_OPT_CLUSTER_SIZE,
 760             .type = QEMU_OPT_SIZE,
 761             .help = "Parallels image cluster size",
 762             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
 763         },
 764         { /* end of list */ }
 765     }
 766 };
 767
 768 static BlockDriver bdrv_parallels = {
 769     .format_name        = "parallels",
 770     .instance_size      = sizeof(BDRVParallelsState),
 771     .bdrv_probe         = parallels_probe,
 772     .bdrv_open          = parallels_open,
 773     .bdrv_close         = parallels_close,
 774     .bdrv_child_perm          = bdrv_format_default_perms,
 775     .bdrv_co_get_block_status = parallels_co_get_block_status,
 776     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
 777     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
 778     .bdrv_co_readv  = parallels_co_readv,
 779     .bdrv_co_writev = parallels_co_writev,
 780
 781     .bdrv_create    = parallels_create,
 782     .bdrv_check     = parallels_check,
 783     .create_opts    = &parallels_create_opts,
 784 };
 785
 786 static void bdrv_parallels_init(void)
 787 {
 788     bdrv_register(&bdrv_parallels);
 789 }
 790
 791 block_init(bdrv_parallels_init);