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                                 PREALLOC_MODE_OFF, NULL);
 228         }
 229         if (ret < 0) {
 230             return ret;
 231         }
 232     }
 233
 234     for (i = 0; i < to_allocate; i++) {
 235         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
 236         s->data_end += s->tracks;
 237         bitmap_set(s->bat_dirty_bmap,
 238                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
 239     }
 240
 241     return bat2sect(s, idx) + sector_num % s->tracks;
 242 }
 243
 244
 245 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
 246 {
 247     BDRVParallelsState *s = bs->opaque;
 248     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
 249     unsigned long bit;
 250
 251     qemu_co_mutex_lock(&s->lock);
 252
 253     bit = find_first_bit(s->bat_dirty_bmap, size);
 254     while (bit < size) {
 255         uint32_t off = bit * s->bat_dirty_block;
 256         uint32_t to_write = s->bat_dirty_block;
 257         int ret;
 258
 259         if (off + to_write > s->header_size) {
 260             to_write = s->header_size - off;
 261         }
 262         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
 263                           to_write);
 264         if (ret < 0) {
 265             qemu_co_mutex_unlock(&s->lock);
 266             return ret;
 267         }
 268         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
 269     }
 270     bitmap_zero(s->bat_dirty_bmap, size);
 271
 272     qemu_co_mutex_unlock(&s->lock);
 273     return 0;
 274 }
 275
 276
 277 static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
 278         int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 279 {
 280     BDRVParallelsState *s = bs->opaque;
 281     int64_t offset;
 282
 283     qemu_co_mutex_lock(&s->lock);
 284     offset = block_status(s, sector_num, nb_sectors, pnum);
 285     qemu_co_mutex_unlock(&s->lock);
 286
 287     if (offset < 0) {
 288         return 0;
 289     }
 290
 291     *file = bs->file->bs;
 292     return (offset << BDRV_SECTOR_BITS) |
 293         BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 294 }
 295
 296 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
 297         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 298 {
 299     BDRVParallelsState *s = bs->opaque;
 300     uint64_t bytes_done = 0;
 301     QEMUIOVector hd_qiov;
 302     int ret = 0;
 303
 304     qemu_iovec_init(&hd_qiov, qiov->niov);
 305
 306     while (nb_sectors > 0) {
 307         int64_t position;
 308         int n, nbytes;
 309
 310         qemu_co_mutex_lock(&s->lock);
 311         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
 312         qemu_co_mutex_unlock(&s->lock);
 313         if (position < 0) {
 314             ret = (int)position;
 315             break;
 316         }
 317
 318         nbytes = n << BDRV_SECTOR_BITS;
 319
 320         qemu_iovec_reset(&hd_qiov);
 321         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 322
 323         ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
 324         if (ret < 0) {
 325             break;
 326         }
 327
 328         nb_sectors -= n;
 329         sector_num += n;
 330         bytes_done += nbytes;
 331     }
 332
 333     qemu_iovec_destroy(&hd_qiov);
 334     return ret;
 335 }
 336
 337 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
 338         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 339 {
 340     BDRVParallelsState *s = bs->opaque;
 341     uint64_t bytes_done = 0;
 342     QEMUIOVector hd_qiov;
 343     int ret = 0;
 344
 345     qemu_iovec_init(&hd_qiov, qiov->niov);
 346
 347     while (nb_sectors > 0) {
 348         int64_t position;
 349         int n, nbytes;
 350
 351         qemu_co_mutex_lock(&s->lock);
 352         position = block_status(s, sector_num, nb_sectors, &n);
 353         qemu_co_mutex_unlock(&s->lock);
 354
 355         nbytes = n << BDRV_SECTOR_BITS;
 356
 357         if (position < 0) {
 358             qemu_iovec_memset(qiov, bytes_done, 0, nbytes);
 359         } else {
 360             qemu_iovec_reset(&hd_qiov);
 361             qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 362
 363             ret = bdrv_co_readv(bs->file, position, n, &hd_qiov);
 364             if (ret < 0) {
 365                 break;
 366             }
 367         }
 368
 369         nb_sectors -= n;
 370         sector_num += n;
 371         bytes_done += nbytes;
 372     }
 373
 374     qemu_iovec_destroy(&hd_qiov);
 375     return ret;
 376 }
 377
 378
 379 static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
 380                            BdrvCheckMode fix)
 381 {
 382     BDRVParallelsState *s = bs->opaque;
 383     int64_t size, prev_off, high_off;
 384     int ret;
 385     uint32_t i;
 386     bool flush_bat = false;
 387     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
 388
 389     size = bdrv_getlength(bs->file->bs);
 390     if (size < 0) {
 391         res->check_errors++;
 392         return size;
 393     }
 394
 395     if (s->header_unclean) {
 396         fprintf(stderr, "%s image was not closed correctly\n",
 397                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
 398         res->corruptions++;
 399         if (fix & BDRV_FIX_ERRORS) {
 400             /* parallels_close will do the job right */
 401             res->corruptions_fixed++;
 402             s->header_unclean = false;
 403         }
 404     }
 405
 406     res->bfi.total_clusters = s->bat_size;
 407     res->bfi.compressed_clusters = 0; /* compression is not supported */
 408
 409     high_off = 0;
 410     prev_off = 0;
 411     for (i = 0; i < s->bat_size; i++) {
 412         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
 413         if (off == 0) {
 414             prev_off = 0;
 415             continue;
 416         }
 417
 418         /* cluster outside the image */
 419         if (off > size) {
 420             fprintf(stderr, "%s cluster %u is outside image\n",
 421                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
 422             res->corruptions++;
 423             if (fix & BDRV_FIX_ERRORS) {
 424                 prev_off = 0;
 425                 s->bat_bitmap[i] = 0;
 426                 res->corruptions_fixed++;
 427                 flush_bat = true;
 428                 continue;
 429             }
 430         }
 431
 432         res->bfi.allocated_clusters++;
 433         if (off > high_off) {
 434             high_off = off;
 435         }
 436
 437         if (prev_off != 0 && (prev_off + cluster_size) != off) {
 438             res->bfi.fragmented_clusters++;
 439         }
 440         prev_off = off;
 441     }
 442
 443     if (flush_bat) {
 444         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
 445         if (ret < 0) {
 446             res->check_errors++;
 447             return ret;
 448         }
 449     }
 450
 451     res->image_end_offset = high_off + cluster_size;
 452     if (size > res->image_end_offset) {
 453         int64_t count;
 454         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
 455         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
 456                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
 457                 size - res->image_end_offset);
 458         res->leaks += count;
 459         if (fix & BDRV_FIX_LEAKS) {
 460             Error *local_err = NULL;
 461             ret = bdrv_truncate(bs->file, res->image_end_offset,
 462                                 PREALLOC_MODE_OFF, &local_err);
 463             if (ret < 0) {
 464                 error_report_err(local_err);
 465                 res->check_errors++;
 466                 return ret;
 467             }
 468             res->leaks_fixed += count;
 469         }
 470     }
 471
 472     return 0;
 473 }
 474
 475
 476 static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
 477 {
 478     int64_t total_size, cl_size;
 479     uint8_t tmp[BDRV_SECTOR_SIZE];
 480     Error *local_err = NULL;
 481     BlockBackend *file;
 482     uint32_t bat_entries, bat_sectors;
 483     ParallelsHeader header;
 484     int ret;
 485
 486     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 487                           BDRV_SECTOR_SIZE);
 488     cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
 489                           DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
 490     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
 491         error_propagate(errp, local_err);
 492         return -E2BIG;
 493     }
 494
 495     ret = bdrv_create_file(filename, opts, &local_err);
 496     if (ret < 0) {
 497         error_propagate(errp, local_err);
 498         return ret;
 499     }
 500
 501     file = blk_new_open(filename, NULL, NULL,
 502                         BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
 503                         &local_err);
 504     if (file == NULL) {
 505         error_propagate(errp, local_err);
 506         return -EIO;
 507     }
 508
 509     blk_set_allow_write_beyond_eof(file, true);
 510
 511     ret = blk_truncate(file, 0, PREALLOC_MODE_OFF, errp);
 512     if (ret < 0) {
 513         goto exit;
 514     }
 515
 516     bat_entries = DIV_ROUND_UP(total_size, cl_size);
 517     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
 518     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
 519
 520     memset(&header, 0, sizeof(header));
 521     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
 522     header.version = cpu_to_le32(HEADER_VERSION);
 523     /* don't care much about geometry, it is not used on image level */
 524     header.heads = cpu_to_le32(16);
 525     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE / 16 / 32);
 526     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
 527     header.bat_entries = cpu_to_le32(bat_entries);
 528     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
 529     header.data_off = cpu_to_le32(bat_sectors);
 530
 531     /* write all the data */
 532     memset(tmp, 0, sizeof(tmp));
 533     memcpy(tmp, &header, sizeof(header));
 534
 535     ret = blk_pwrite(file, 0, tmp, BDRV_SECTOR_SIZE, 0);
 536     if (ret < 0) {
 537         goto exit;
 538     }
 539     ret = blk_pwrite_zeroes(file, BDRV_SECTOR_SIZE,
 540                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
 541     if (ret < 0) {
 542         goto exit;
 543     }
 544     ret = 0;
 545
 546 done:
 547     blk_unref(file);
 548     return ret;
 549
 550 exit:
 551     error_setg_errno(errp, -ret, "Failed to create Parallels image");
 552     goto done;
 553 }
 554
 555
 556 static int parallels_probe(const uint8_t *buf, int buf_size,
 557                            const char *filename)
 558 {
 559     const ParallelsHeader *ph = (const void *)buf;
 560
 561     if (buf_size < sizeof(ParallelsHeader)) {
 562         return 0;
 563     }
 564
 565     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
 566            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
 567            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
 568         return 100;
 569     }
 570
 571     return 0;
 572 }
 573
 574 static int parallels_update_header(BlockDriverState *bs)
 575 {
 576     BDRVParallelsState *s = bs->opaque;
 577     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
 578                         sizeof(ParallelsHeader));
 579
 580     if (size > s->header_size) {
 581         size = s->header_size;
 582     }
 583     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
 584 }
 585
 586 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
 587                           Error **errp)
 588 {
 589     BDRVParallelsState *s = bs->opaque;
 590     ParallelsHeader ph;
 591     int ret, size, i;
 592     QemuOpts *opts = NULL;
 593     Error *local_err = NULL;
 594     char *buf;
 595
 596     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
 597                                false, errp);
 598     if (!bs->file) {
 599         return -EINVAL;
 600     }
 601
 602     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
 603     if (ret < 0) {
 604         goto fail;
 605     }
 606
 607     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
 608
 609     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
 610         goto fail_format;
 611     }
 612     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
 613         s->off_multiplier = 1;
 614         bs->total_sectors = 0xffffffff & bs->total_sectors;
 615     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
 616         s->off_multiplier = le32_to_cpu(ph.tracks);
 617     } else {
 618         goto fail_format;
 619     }
 620
 621     s->tracks = le32_to_cpu(ph.tracks);
 622     if (s->tracks == 0) {
 623         error_setg(errp, "Invalid image: Zero sectors per track");
 624         ret = -EINVAL;
 625         goto fail;
 626     }
 627     if (s->tracks > INT32_MAX/513) {
 628         error_setg(errp, "Invalid image: Too big cluster");
 629         ret = -EFBIG;
 630         goto fail;
 631     }
 632
 633     s->bat_size = le32_to_cpu(ph.bat_entries);
 634     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
 635         error_setg(errp, "Catalog too large");
 636         ret = -EFBIG;
 637         goto fail;
 638     }
 639
 640     size = bat_entry_off(s->bat_size);
 641     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
 642     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
 643     if (s->header == NULL) {
 644         ret = -ENOMEM;
 645         goto fail;
 646     }
 647     s->data_end = le32_to_cpu(ph.data_off);
 648     if (s->data_end == 0) {
 649         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
 650     }
 651     if (s->data_end < s->header_size) {
 652         /* there is not enough unused space to fit to block align between BAT
 653            and actual data. We can't avoid read-modify-write... */
 654         s->header_size = size;
 655     }
 656
 657     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
 658     if (ret < 0) {
 659         goto fail;
 660     }
 661     s->bat_bitmap = (uint32_t *)(s->header + 1);
 662
 663     for (i = 0; i < s->bat_size; i++) {
 664         int64_t off = bat2sect(s, i);
 665         if (off >= s->data_end) {
 666             s->data_end = off + s->tracks;
 667         }
 668     }
 669
 670     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
 671         /* Image was not closed correctly. The check is mandatory */
 672         s->header_unclean = true;
 673         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
 674             error_setg(errp, "parallels: Image was not closed correctly; "
 675                        "cannot be opened read/write");
 676             ret = -EACCES;
 677             goto fail;
 678         }
 679     }
 680
 681     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
 682     if (local_err != NULL) {
 683         goto fail_options;
 684     }
 685
 686     qemu_opts_absorb_qdict(opts, options, &local_err);
 687     if (local_err != NULL) {
 688         goto fail_options;
 689     }
 690
 691     s->prealloc_size =
 692         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
 693     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
 694     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
 695     s->prealloc_mode = qapi_enum_parse(prealloc_mode_lookup, buf,
 696             PRL_PREALLOC_MODE__MAX, PRL_PREALLOC_MODE_FALLOCATE, &local_err);
 697     g_free(buf);
 698     if (local_err != NULL) {
 699         goto fail_options;
 700     }
 701
 702     if (!(flags & BDRV_O_RESIZE) || !bdrv_has_zero_init(bs->file->bs) ||
 703             bdrv_truncate(bs->file, bdrv_getlength(bs->file->bs),
 704                           PREALLOC_MODE_OFF, NULL) != 0) {
 705         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
 706     }
 707
 708     if (flags & BDRV_O_RDWR) {
 709         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
 710         ret = parallels_update_header(bs);
 711         if (ret < 0) {
 712             goto fail;
 713         }
 714     }
 715
 716     s->bat_dirty_block = 4 * getpagesize();
 717     s->bat_dirty_bmap =
 718         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
 719
 720     qemu_co_mutex_init(&s->lock);
 721     return 0;
 722
 723 fail_format:
 724     error_setg(errp, "Image not in Parallels format");
 725     ret = -EINVAL;
 726 fail:
 727     qemu_vfree(s->header);
 728     return ret;
 729
 730 fail_options:
 731     error_propagate(errp, local_err);
 732     ret = -EINVAL;
 733     goto fail;
 734 }
 735
 736
 737 static void parallels_close(BlockDriverState *bs)
 738 {
 739     BDRVParallelsState *s = bs->opaque;
 740
 741     if (bs->open_flags & BDRV_O_RDWR) {
 742         s->header->inuse = 0;
 743         parallels_update_header(bs);
 744     }
 745
 746     if (bs->open_flags & BDRV_O_RDWR) {
 747         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
 748                       PREALLOC_MODE_OFF, NULL);
 749     }
 750
 751     g_free(s->bat_dirty_bmap);
 752     qemu_vfree(s->header);
 753 }
 754
 755 static QemuOptsList parallels_create_opts = {
 756     .name = "parallels-create-opts",
 757     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
 758     .desc = {
 759         {
 760             .name = BLOCK_OPT_SIZE,
 761             .type = QEMU_OPT_SIZE,
 762             .help = "Virtual disk size",
 763         },
 764         {
 765             .name = BLOCK_OPT_CLUSTER_SIZE,
 766             .type = QEMU_OPT_SIZE,
 767             .help = "Parallels image cluster size",
 768             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
 769         },
 770         { /* end of list */ }
 771     }
 772 };
 773
 774 static BlockDriver bdrv_parallels = {
 775     .format_name        = "parallels",
 776     .instance_size      = sizeof(BDRVParallelsState),
 777     .bdrv_probe         = parallels_probe,
 778     .bdrv_open          = parallels_open,
 779     .bdrv_close         = parallels_close,
 780     .bdrv_child_perm          = bdrv_format_default_perms,
 781     .bdrv_co_get_block_status = parallels_co_get_block_status,
 782     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
 783     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
 784     .bdrv_co_readv  = parallels_co_readv,
 785     .bdrv_co_writev = parallels_co_writev,
 786
 787     .bdrv_create    = parallels_create,
 788     .bdrv_check     = parallels_check,
 789     .create_opts    = &parallels_create_opts,
 790 };
 791
 792 static void bdrv_parallels_init(void)
 793 {
 794     bdrv_register(&bdrv_parallels);
 795 }
 796
 797 block_init(bdrv_parallels_init);