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, len;
 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     len = bdrv_getlength(bs->file->bs);
 218     if (len < 0) {
 219         return len;
 220     }
 221     if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
 222         int ret;
 223         space += s->prealloc_size;
 224         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
 225             ret = bdrv_pwrite_zeroes(bs->file,
 226                                      s->data_end << BDRV_SECTOR_BITS,
 227                                      space << BDRV_SECTOR_BITS, 0);
 228         } else {
 229             ret = bdrv_truncate(bs->file,
 230                                 (s->data_end + space) << BDRV_SECTOR_BITS,
 231                                 PREALLOC_MODE_OFF, NULL);
 232         }
 233         if (ret < 0) {
 234             return ret;
 235         }
 236     }
 237
 238     for (i = 0; i < to_allocate; i++) {
 239         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
 240         s->data_end += s->tracks;
 241         bitmap_set(s->bat_dirty_bmap,
 242                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
 243     }
 244
 245     return bat2sect(s, idx) + sector_num % s->tracks;
 246 }
 247
 248
 249 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
 250 {
 251     BDRVParallelsState *s = bs->opaque;
 252     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
 253     unsigned long bit;
 254
 255     qemu_co_mutex_lock(&s->lock);
 256
 257     bit = find_first_bit(s->bat_dirty_bmap, size);
 258     while (bit < size) {
 259         uint32_t off = bit * s->bat_dirty_block;
 260         uint32_t to_write = s->bat_dirty_block;
 261         int ret;
 262
 263         if (off + to_write > s->header_size) {
 264             to_write = s->header_size - off;
 265         }
 266         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
 267                           to_write);
 268         if (ret < 0) {
 269             qemu_co_mutex_unlock(&s->lock);
 270             return ret;
 271         }
 272         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
 273     }
 274     bitmap_zero(s->bat_dirty_bmap, size);
 275
 276     qemu_co_mutex_unlock(&s->lock);
 277     return 0;
 278 }
 279
 280
 281 static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
 282         int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 283 {
 284     BDRVParallelsState *s = bs->opaque;
 285     int64_t offset;
 286
 287     qemu_co_mutex_lock(&s->lock);
 288     offset = block_status(s, sector_num, nb_sectors, pnum);
 289     qemu_co_mutex_unlock(&s->lock);
 290
 291     if (offset < 0) {
 292         return 0;
 293     }
 294
 295     *file = bs->file->bs;
 296     return (offset << BDRV_SECTOR_BITS) |
 297         BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 298 }
 299
 300 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
 301         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 302 {
 303     BDRVParallelsState *s = bs->opaque;
 304     uint64_t bytes_done = 0;
 305     QEMUIOVector hd_qiov;
 306     int ret = 0;
 307
 308     qemu_iovec_init(&hd_qiov, qiov->niov);
 309
 310     while (nb_sectors > 0) {
 311         int64_t position;
 312         int n, nbytes;
 313
 314         qemu_co_mutex_lock(&s->lock);
 315         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
 316         qemu_co_mutex_unlock(&s->lock);
 317         if (position < 0) {
 318             ret = (int)position;
 319             break;
 320         }
 321
 322         nbytes = n << BDRV_SECTOR_BITS;
 323
 324         qemu_iovec_reset(&hd_qiov);
 325         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 326
 327         ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
 328         if (ret < 0) {
 329             break;
 330         }
 331
 332         nb_sectors -= n;
 333         sector_num += n;
 334         bytes_done += nbytes;
 335     }
 336
 337     qemu_iovec_destroy(&hd_qiov);
 338     return ret;
 339 }
 340
 341 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
 342         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 343 {
 344     BDRVParallelsState *s = bs->opaque;
 345     uint64_t bytes_done = 0;
 346     QEMUIOVector hd_qiov;
 347     int ret = 0;
 348
 349     qemu_iovec_init(&hd_qiov, qiov->niov);
 350
 351     while (nb_sectors > 0) {
 352         int64_t position;
 353         int n, nbytes;
 354
 355         qemu_co_mutex_lock(&s->lock);
 356         position = block_status(s, sector_num, nb_sectors, &n);
 357         qemu_co_mutex_unlock(&s->lock);
 358
 359         nbytes = n << BDRV_SECTOR_BITS;
 360
 361         if (position < 0) {
 362             qemu_iovec_memset(qiov, bytes_done, 0, nbytes);
 363         } else {
 364             qemu_iovec_reset(&hd_qiov);
 365             qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 366
 367             ret = bdrv_co_readv(bs->file, position, n, &hd_qiov);
 368             if (ret < 0) {
 369                 break;
 370             }
 371         }
 372
 373         nb_sectors -= n;
 374         sector_num += n;
 375         bytes_done += nbytes;
 376     }
 377
 378     qemu_iovec_destroy(&hd_qiov);
 379     return ret;
 380 }
 381
 382
 383 static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
 384                            BdrvCheckMode fix)
 385 {
 386     BDRVParallelsState *s = bs->opaque;
 387     int64_t size, prev_off, high_off;
 388     int ret;
 389     uint32_t i;
 390     bool flush_bat = false;
 391     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
 392
 393     size = bdrv_getlength(bs->file->bs);
 394     if (size < 0) {
 395         res->check_errors++;
 396         return size;
 397     }
 398
 399     if (s->header_unclean) {
 400         fprintf(stderr, "%s image was not closed correctly\n",
 401                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
 402         res->corruptions++;
 403         if (fix & BDRV_FIX_ERRORS) {
 404             /* parallels_close will do the job right */
 405             res->corruptions_fixed++;
 406             s->header_unclean = false;
 407         }
 408     }
 409
 410     res->bfi.total_clusters = s->bat_size;
 411     res->bfi.compressed_clusters = 0; /* compression is not supported */
 412
 413     high_off = 0;
 414     prev_off = 0;
 415     for (i = 0; i < s->bat_size; i++) {
 416         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
 417         if (off == 0) {
 418             prev_off = 0;
 419             continue;
 420         }
 421
 422         /* cluster outside the image */
 423         if (off > size) {
 424             fprintf(stderr, "%s cluster %u is outside image\n",
 425                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
 426             res->corruptions++;
 427             if (fix & BDRV_FIX_ERRORS) {
 428                 prev_off = 0;
 429                 s->bat_bitmap[i] = 0;
 430                 res->corruptions_fixed++;
 431                 flush_bat = true;
 432                 continue;
 433             }
 434         }
 435
 436         res->bfi.allocated_clusters++;
 437         if (off > high_off) {
 438             high_off = off;
 439         }
 440
 441         if (prev_off != 0 && (prev_off + cluster_size) != off) {
 442             res->bfi.fragmented_clusters++;
 443         }
 444         prev_off = off;
 445     }
 446
 447     if (flush_bat) {
 448         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
 449         if (ret < 0) {
 450             res->check_errors++;
 451             return ret;
 452         }
 453     }
 454
 455     res->image_end_offset = high_off + cluster_size;
 456     if (size > res->image_end_offset) {
 457         int64_t count;
 458         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
 459         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
 460                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
 461                 size - res->image_end_offset);
 462         res->leaks += count;
 463         if (fix & BDRV_FIX_LEAKS) {
 464             Error *local_err = NULL;
 465             ret = bdrv_truncate(bs->file, res->image_end_offset,
 466                                 PREALLOC_MODE_OFF, &local_err);
 467             if (ret < 0) {
 468                 error_report_err(local_err);
 469                 res->check_errors++;
 470                 return ret;
 471             }
 472             res->leaks_fixed += count;
 473         }
 474     }
 475
 476     return 0;
 477 }
 478
 479
 480 static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
 481 {
 482     int64_t total_size, cl_size;
 483     uint8_t tmp[BDRV_SECTOR_SIZE];
 484     Error *local_err = NULL;
 485     BlockBackend *file;
 486     uint32_t bat_entries, bat_sectors;
 487     ParallelsHeader header;
 488     int ret;
 489
 490     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 491                           BDRV_SECTOR_SIZE);
 492     cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
 493                           DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
 494     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
 495         error_propagate(errp, local_err);
 496         return -E2BIG;
 497     }
 498
 499     ret = bdrv_create_file(filename, opts, &local_err);
 500     if (ret < 0) {
 501         error_propagate(errp, local_err);
 502         return ret;
 503     }
 504
 505     file = blk_new_open(filename, NULL, NULL,
 506                         BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
 507                         &local_err);
 508     if (file == NULL) {
 509         error_propagate(errp, local_err);
 510         return -EIO;
 511     }
 512
 513     blk_set_allow_write_beyond_eof(file, true);
 514
 515     ret = blk_truncate(file, 0, PREALLOC_MODE_OFF, errp);
 516     if (ret < 0) {
 517         goto exit;
 518     }
 519
 520     bat_entries = DIV_ROUND_UP(total_size, cl_size);
 521     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
 522     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
 523
 524     memset(&header, 0, sizeof(header));
 525     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
 526     header.version = cpu_to_le32(HEADER_VERSION);
 527     /* don't care much about geometry, it is not used on image level */
 528     header.heads = cpu_to_le32(16);
 529     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE / 16 / 32);
 530     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
 531     header.bat_entries = cpu_to_le32(bat_entries);
 532     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
 533     header.data_off = cpu_to_le32(bat_sectors);
 534
 535     /* write all the data */
 536     memset(tmp, 0, sizeof(tmp));
 537     memcpy(tmp, &header, sizeof(header));
 538
 539     ret = blk_pwrite(file, 0, tmp, BDRV_SECTOR_SIZE, 0);
 540     if (ret < 0) {
 541         goto exit;
 542     }
 543     ret = blk_pwrite_zeroes(file, BDRV_SECTOR_SIZE,
 544                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
 545     if (ret < 0) {
 546         goto exit;
 547     }
 548     ret = 0;
 549
 550 done:
 551     blk_unref(file);
 552     return ret;
 553
 554 exit:
 555     error_setg_errno(errp, -ret, "Failed to create Parallels image");
 556     goto done;
 557 }
 558
 559
 560 static int parallels_probe(const uint8_t *buf, int buf_size,
 561                            const char *filename)
 562 {
 563     const ParallelsHeader *ph = (const void *)buf;
 564
 565     if (buf_size < sizeof(ParallelsHeader)) {
 566         return 0;
 567     }
 568
 569     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
 570            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
 571            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
 572         return 100;
 573     }
 574
 575     return 0;
 576 }
 577
 578 static int parallels_update_header(BlockDriverState *bs)
 579 {
 580     BDRVParallelsState *s = bs->opaque;
 581     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
 582                         sizeof(ParallelsHeader));
 583
 584     if (size > s->header_size) {
 585         size = s->header_size;
 586     }
 587     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
 588 }
 589
 590 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
 591                           Error **errp)
 592 {
 593     BDRVParallelsState *s = bs->opaque;
 594     ParallelsHeader ph;
 595     int ret, size, i;
 596     QemuOpts *opts = NULL;
 597     Error *local_err = NULL;
 598     char *buf;
 599
 600     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
 601                                false, errp);
 602     if (!bs->file) {
 603         return -EINVAL;
 604     }
 605
 606     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
 607     if (ret < 0) {
 608         goto fail;
 609     }
 610
 611     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
 612
 613     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
 614         goto fail_format;
 615     }
 616     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
 617         s->off_multiplier = 1;
 618         bs->total_sectors = 0xffffffff & bs->total_sectors;
 619     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
 620         s->off_multiplier = le32_to_cpu(ph.tracks);
 621     } else {
 622         goto fail_format;
 623     }
 624
 625     s->tracks = le32_to_cpu(ph.tracks);
 626     if (s->tracks == 0) {
 627         error_setg(errp, "Invalid image: Zero sectors per track");
 628         ret = -EINVAL;
 629         goto fail;
 630     }
 631     if (s->tracks > INT32_MAX/513) {
 632         error_setg(errp, "Invalid image: Too big cluster");
 633         ret = -EFBIG;
 634         goto fail;
 635     }
 636
 637     s->bat_size = le32_to_cpu(ph.bat_entries);
 638     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
 639         error_setg(errp, "Catalog too large");
 640         ret = -EFBIG;
 641         goto fail;
 642     }
 643
 644     size = bat_entry_off(s->bat_size);
 645     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
 646     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
 647     if (s->header == NULL) {
 648         ret = -ENOMEM;
 649         goto fail;
 650     }
 651     s->data_end = le32_to_cpu(ph.data_off);
 652     if (s->data_end == 0) {
 653         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
 654     }
 655     if (s->data_end < s->header_size) {
 656         /* there is not enough unused space to fit to block align between BAT
 657            and actual data. We can't avoid read-modify-write... */
 658         s->header_size = size;
 659     }
 660
 661     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
 662     if (ret < 0) {
 663         goto fail;
 664     }
 665     s->bat_bitmap = (uint32_t *)(s->header + 1);
 666
 667     for (i = 0; i < s->bat_size; i++) {
 668         int64_t off = bat2sect(s, i);
 669         if (off >= s->data_end) {
 670             s->data_end = off + s->tracks;
 671         }
 672     }
 673
 674     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
 675         /* Image was not closed correctly. The check is mandatory */
 676         s->header_unclean = true;
 677         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
 678             error_setg(errp, "parallels: Image was not closed correctly; "
 679                        "cannot be opened read/write");
 680             ret = -EACCES;
 681             goto fail;
 682         }
 683     }
 684
 685     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
 686     if (local_err != NULL) {
 687         goto fail_options;
 688     }
 689
 690     qemu_opts_absorb_qdict(opts, options, &local_err);
 691     if (local_err != NULL) {
 692         goto fail_options;
 693     }
 694
 695     s->prealloc_size =
 696         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
 697     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
 698     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
 699     s->prealloc_mode = qapi_enum_parse(prealloc_mode_lookup, buf,
 700             PRL_PREALLOC_MODE__MAX, PRL_PREALLOC_MODE_FALLOCATE, &local_err);
 701     g_free(buf);
 702     if (local_err != NULL) {
 703         goto fail_options;
 704     }
 705
 706     if (!bdrv_has_zero_init(bs->file->bs)) {
 707         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
 708     }
 709
 710     if (flags & BDRV_O_RDWR) {
 711         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
 712         ret = parallels_update_header(bs);
 713         if (ret < 0) {
 714             goto fail;
 715         }
 716     }
 717
 718     s->bat_dirty_block = 4 * getpagesize();
 719     s->bat_dirty_bmap =
 720         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
 721
 722     qemu_co_mutex_init(&s->lock);
 723     return 0;
 724
 725 fail_format:
 726     error_setg(errp, "Image not in Parallels format");
 727     ret = -EINVAL;
 728 fail:
 729     qemu_vfree(s->header);
 730     return ret;
 731
 732 fail_options:
 733     error_propagate(errp, local_err);
 734     ret = -EINVAL;
 735     goto fail;
 736 }
 737
 738
 739 static void parallels_close(BlockDriverState *bs)
 740 {
 741     BDRVParallelsState *s = bs->opaque;
 742
 743     if (bs->open_flags & BDRV_O_RDWR) {
 744         s->header->inuse = 0;
 745         parallels_update_header(bs);
 746     }
 747
 748     if (bs->open_flags & BDRV_O_RDWR) {
 749         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
 750                       PREALLOC_MODE_OFF, NULL);
 751     }
 752
 753     g_free(s->bat_dirty_bmap);
 754     qemu_vfree(s->header);
 755 }
 756
 757 static QemuOptsList parallels_create_opts = {
 758     .name = "parallels-create-opts",
 759     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
 760     .desc = {
 761         {
 762             .name = BLOCK_OPT_SIZE,
 763             .type = QEMU_OPT_SIZE,
 764             .help = "Virtual disk size",
 765         },
 766         {
 767             .name = BLOCK_OPT_CLUSTER_SIZE,
 768             .type = QEMU_OPT_SIZE,
 769             .help = "Parallels image cluster size",
 770             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
 771         },
 772         { /* end of list */ }
 773     }
 774 };
 775
 776 static BlockDriver bdrv_parallels = {
 777     .format_name        = "parallels",
 778     .instance_size      = sizeof(BDRVParallelsState),
 779     .bdrv_probe         = parallels_probe,
 780     .bdrv_open          = parallels_open,
 781     .bdrv_close         = parallels_close,
 782     .bdrv_child_perm          = bdrv_format_default_perms,
 783     .bdrv_co_get_block_status = parallels_co_get_block_status,
 784     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
 785     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
 786     .bdrv_co_readv  = parallels_co_readv,
 787     .bdrv_co_writev = parallels_co_writev,
 788
 789     .bdrv_create    = parallels_create,
 790     .bdrv_check     = parallels_check,
 791     .create_opts    = &parallels_create_opts,
 792 };
 793
 794 static void bdrv_parallels_init(void)
 795 {
 796     bdrv_register(&bdrv_parallels);
 797 }
 798
 799 block_init(bdrv_parallels_init);