text: /*
   * Block driver for the VMDK format
   *
   * Copyright (c) 2004 Fabrice Bellard
   * Copyright (c) 2005 Filip Navara
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include "qemu/osdep.h"
  #include "qapi/error.h"
  #include "block/block_int.h"
  #include "sysemu/block-backend.h"
  #include "qapi/qmp/qdict.h"
  #include "qapi/qmp/qerror.h"
  #include "qemu/error-report.h"
  #include "qemu/module.h"
  #include "qemu/option.h"
  #include "qemu/bswap.h"
  #include "migration/blocker.h"
  #include "qemu/cutils.h"
  #include <zlib.h>
  
  #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
  #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
  #define VMDK4_COMPRESSION_DEFLATE 1
  #define VMDK4_FLAG_NL_DETECT (1 << 0)
  #define VMDK4_FLAG_RGD (1 << 1)
  /* Zeroed-grain enable bit */
  #define VMDK4_FLAG_ZERO_GRAIN   (1 << 2)
  #define VMDK4_FLAG_COMPRESS (1 << 16)
  #define VMDK4_FLAG_MARKER (1 << 17)
  #define VMDK4_GD_AT_END 0xffffffffffffffffULL
  
  #define VMDK_EXTENT_MAX_SECTORS (1ULL << 32)
  
  #define VMDK_GTE_ZEROED 0x1
  
  /* VMDK internal error codes */
  #define VMDK_OK      0
  #define VMDK_ERROR   (-1)
  /* Cluster not allocated */
  #define VMDK_UNALLOC (-2)
  #define VMDK_ZEROED  (-3)
  
  #define BLOCK_OPT_ZEROED_GRAIN "zeroed_grain"
  
  typedef struct {
      uint32_t version;
      uint32_t flags;
      uint32_t disk_sectors;
      uint32_t granularity;
      uint32_t l1dir_offset;
      uint32_t l1dir_size;
      uint32_t file_sectors;
      uint32_t cylinders;
      uint32_t heads;
      uint32_t sectors_per_track;
  } QEMU_PACKED VMDK3Header;
  
  typedef struct {
      uint32_t version;
      uint32_t flags;
      uint64_t capacity;
      uint64_t granularity;
      uint64_t desc_offset;
      uint64_t desc_size;
      /* Number of GrainTableEntries per GrainTable */
      uint32_t num_gtes_per_gt;
      uint64_t rgd_offset;
      uint64_t gd_offset;
      uint64_t grain_offset;
      char filler[1];
      char check_bytes[4];
      uint16_t compressAlgorithm;
  } QEMU_PACKED VMDK4Header;
  
  typedef struct VMDKSESparseConstHeader {
      uint64_t magic;
      uint64_t version;
      uint64_t capacity;
      uint64_t grain_size;
      uint64_t grain_table_size;
      uint64_t flags;
      uint64_t reserved1;
      uint64_t reserved2;
      uint64_t reserved3;
      uint64_t reserved4;
      uint64_t volatile_header_offset;
      uint64_t volatile_header_size;
      uint64_t journal_header_offset;
      uint64_t journal_header_size;
      uint64_t journal_offset;
      uint64_t journal_size;
      uint64_t grain_dir_offset;
      uint64_t grain_dir_size;
      uint64_t grain_tables_offset;
      uint64_t grain_tables_size;
      uint64_t free_bitmap_offset;
      uint64_t free_bitmap_size;
      uint64_t backmap_offset;
      uint64_t backmap_size;
      uint64_t grains_offset;
      uint64_t grains_size;
      uint8_t pad[304];
  } QEMU_PACKED VMDKSESparseConstHeader;
  
  typedef struct VMDKSESparseVolatileHeader {
      uint64_t magic;
      uint64_t free_gt_number;
      uint64_t next_txn_seq_number;
      uint64_t replay_journal;
      uint8_t pad[480];
  } QEMU_PACKED VMDKSESparseVolatileHeader;
  
  #define L2_CACHE_SIZE 16
  
  typedef struct VmdkExtent {
      BdrvChild *file;
      bool flat;
      bool compressed;
      bool has_marker;
      bool has_zero_grain;
      bool sesparse;
      uint64_t sesparse_l2_tables_offset;
      uint64_t sesparse_clusters_offset;
      int32_t entry_size;
      int version;
      int64_t sectors;
      int64_t end_sector;
      int64_t flat_start_offset;
      int64_t l1_table_offset;
      int64_t l1_backup_table_offset;
      void *l1_table;
      uint32_t *l1_backup_table;
      unsigned int l1_size;
      uint32_t l1_entry_sectors;
  
      unsigned int l2_size;
      void *l2_cache;
      uint32_t l2_cache_offsets[L2_CACHE_SIZE];
      uint32_t l2_cache_counts[L2_CACHE_SIZE];
  
      int64_t cluster_sectors;
      int64_t next_cluster_sector;
      char *type;
  } VmdkExtent;
  
  typedef struct BDRVVmdkState {
      CoMutex lock;
      uint64_t desc_offset;
      bool cid_updated;
      bool cid_checked;
      uint32_t cid;
      uint32_t parent_cid;
      int num_extents;
      /* Extent array with num_extents entries, ascend ordered by address */
      VmdkExtent *extents;
      Error *migration_blocker;
      char *create_type;
  } BDRVVmdkState;
  
  typedef struct VmdkMetaData {
      unsigned int l1_index;
      unsigned int l2_index;
      unsigned int l2_offset;
      bool new_allocation;
      uint32_t *l2_cache_entry;
  } VmdkMetaData;
  
  typedef struct VmdkGrainMarker {
      uint64_t lba;
      uint32_t size;
      uint8_t  data[];
  } QEMU_PACKED VmdkGrainMarker;
  
  enum {
      MARKER_END_OF_STREAM    = 0,
      MARKER_GRAIN_TABLE      = 1,
      MARKER_GRAIN_DIRECTORY  = 2,
      MARKER_FOOTER           = 3,
  };
  
  static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
  {
      uint32_t magic;
  
      if (buf_size < 4) {
          return 0;
      }
      magic = be32_to_cpu(*(uint32_t *)buf);
      if (magic == VMDK3_MAGIC ||
          magic == VMDK4_MAGIC) {
          return 100;
      } else {
          const char *p = (const char *)buf;
          const char *end = p + buf_size;
          while (p < end) {
              if (*p == '#') {
                  /* skip comment line */
                  while (p < end && *p != '\n') {
                      p++;
                  }
                  p++;
                  continue;
              }
              if (*p == ' ') {
                  while (p < end && *p == ' ') {
                      p++;
                  }
                  /* skip '\r' if windows line endings used. */
                  if (p < end && *p == '\r') {
                      p++;
                  }
                  /* only accept blank lines before 'version=' line */
                  if (p == end || *p != '\n') {
                      return 0;
                  }
                  p++;
                  continue;
              }
              if (end - p >= strlen("version=X\n")) {
                  if (strncmp("version=1\n", p, strlen("version=1\n")) == 0 ||
                      strncmp("version=2\n", p, strlen("version=2\n")) == 0 ||
                      strncmp("version=3\n", p, strlen("version=3\n")) == 0) {
                      return 100;
                  }
              }
              if (end - p >= strlen("version=X\r\n")) {
                  if (strncmp("version=1\r\n", p, strlen("version=1\r\n")) == 0 ||
                      strncmp("version=2\r\n", p, strlen("version=2\r\n")) == 0 ||
                      strncmp("version=3\r\n", p, strlen("version=3\r\n")) == 0) {
                      return 100;
                  }
              }
              return 0;
          }
          return 0;
      }
  }
  
  #define SECTOR_SIZE 512
  #define DESC_SIZE (20 * SECTOR_SIZE)    /* 20 sectors of 512 bytes each */
  #define BUF_SIZE 4096
  #define HEADER_SIZE 512                 /* first sector of 512 bytes */
  
  static void vmdk_free_extents(BlockDriverState *bs)
  {
      int i;
      BDRVVmdkState *s = bs->opaque;
      VmdkExtent *e;
  
      for (i = 0; i < s->num_extents; i++) {
          e = &s->extents[i];
          g_free(e->l1_table);
          g_free(e->l2_cache);
          g_free(e->l1_backup_table);
          g_free(e->type);
          if (e->file != bs->file) {
              bdrv_unref_child(bs, e->file);
          }
      }
      g_free(s->extents);
  }
  
  static void vmdk_free_last_extent(BlockDriverState *bs)
  {
      BDRVVmdkState *s = bs->opaque;
  
      if (s->num_extents == 0) {
          return;
      }
      s->num_extents--;
      s->extents = g_renew(VmdkExtent, s->extents, s->num_extents);
  }
  
  /* Return -ve errno, or 0 on success and write CID into *pcid. */
  static int vmdk_read_cid(BlockDriverState *bs, int parent, uint32_t *pcid)
  {
      char *desc;
      uint32_t cid;
      const char *p_name, *cid_str;
      size_t cid_str_size;
      BDRVVmdkState *s = bs->opaque;
      int ret;
  
      desc = g_malloc0(DESC_SIZE);
      ret = bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE);
      if (ret < 0) {
          goto out;
      }
  
      if (parent) {
          cid_str = "parentCID";
          cid_str_size = sizeof("parentCID");
      } else {
          cid_str = "CID";
          cid_str_size = sizeof("CID");
      }
  
      desc[DESC_SIZE - 1] = '\0';
      p_name = strstr(desc, cid_str);
      if (p_name == NULL) {
          ret = -EINVAL;
          goto out;
      }
      p_name += cid_str_size;
      if (sscanf(p_name, "%" SCNx32, &cid) != 1) {
          ret = -EINVAL;
          goto out;
      }
      *pcid = cid;
      ret = 0;
  
  out:
      g_free(desc);
      return ret;
  }
  
  static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
  {
      char *desc, *tmp_desc;
      char *p_name, *tmp_str;
      BDRVVmdkState *s = bs->opaque;
      int ret = 0;
  
      desc = g_malloc0(DESC_SIZE);
      tmp_desc = g_malloc0(DESC_SIZE);
      ret = bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE);
      if (ret < 0) {
          goto out;
      }
  
      desc[DESC_SIZE - 1] = '\0';
      tmp_str = strstr(desc, "parentCID");
      if (tmp_str == NULL) {
          ret = -EINVAL;
          goto out;
      }
  
      pstrcpy(tmp_desc, DESC_SIZE, tmp_str);
      p_name = strstr(desc, "CID");
      if (p_name != NULL) {
          p_name += sizeof("CID");
          snprintf(p_name, DESC_SIZE - (p_name - desc), "%" PRIx32 "\n", cid);
          pstrcat(desc, DESC_SIZE, tmp_desc);
      }
  
      ret = bdrv_pwrite_sync(bs->file, s->desc_offset, desc, DESC_SIZE);
  
  out:
      g_free(desc);
      g_free(tmp_desc);
      return ret;
  }
  
  static int vmdk_is_cid_valid(BlockDriverState *bs)
  {
      BDRVVmdkState *s = bs->opaque;
      uint32_t cur_pcid;
  
      if (!s->cid_checked && bs->backing) {
          BlockDriverState *p_bs = bs->backing->bs;
  
          if (strcmp(p_bs->drv->format_name, "vmdk")) {
              /* Backing file is not in vmdk format, so it does not have
               * a CID, which makes the overlay's parent CID invalid */
              return 0;
          }
  
          if (vmdk_read_cid(p_bs, 0, &cur_pcid) != 0) {
              /* read failure: report as not valid */
              return 0;
          }
          if (s->parent_cid != cur_pcid) {
              /* CID not valid */
              return 0;
          }
      }
      s->cid_checked = true;
      /* CID valid */
      return 1;
  }
  
  /* We have nothing to do for VMDK reopen, stubs just return success */
  static int vmdk_reopen_prepare(BDRVReopenState *state,
                                 BlockReopenQueue *queue, Error **errp)
  {
      assert(state != NULL);
      assert(state->bs != NULL);
      return 0;
  }
  
  static int vmdk_parent_open(BlockDriverState *bs)
  {
      char *p_name;
      char *desc;
      BDRVVmdkState *s = bs->opaque;
      int ret;
  
      desc = g_malloc0(DESC_SIZE + 1);
      ret = bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE);
      if (ret < 0) {
          goto out;
      }
      ret = 0;
  
      p_name = strstr(desc, "parentFileNameHint");
      if (p_name != NULL) {
          char *end_name;
  
          p_name += sizeof("parentFileNameHint") + 1;
          end_name = strchr(p_name, '\"');
          if (end_name == NULL) {
              ret = -EINVAL;
              goto out;
          }
          if ((end_name - p_name) > sizeof(bs->auto_backing_file) - 1) {
              ret = -EINVAL;
              goto out;
          }
  
          pstrcpy(bs->auto_backing_file, end_name - p_name + 1, p_name);
          pstrcpy(bs->backing_file, sizeof(bs->backing_file),
                  bs->auto_backing_file);
          pstrcpy(bs->backing_format, sizeof(bs->backing_format),
                  "vmdk");
      }
  
  out:
      g_free(desc);
      return ret;
  }
  
  /* Create and append extent to the extent array. Return the added VmdkExtent
   * address. return NULL if allocation failed. */
  static int vmdk_add_extent(BlockDriverState *bs,
                             BdrvChild *file, bool flat, int64_t sectors,
                             int64_t l1_offset, int64_t l1_backup_offset,
                             uint32_t l1_size,
                             int l2_size, uint64_t cluster_sectors,
                             VmdkExtent **new_extent,
                             Error **errp)
  {
      VmdkExtent *extent;
      BDRVVmdkState *s = bs->opaque;
      int64_t nb_sectors;
  
      if (cluster_sectors > 0x200000) {
          /* 0x200000 * 512Bytes = 1GB for one cluster is unrealistic */
          error_setg(errp, "Invalid granularity, image may be corrupt");
          return -EFBIG;
      }
      if (l1_size > 32 * 1024 * 1024) {
          /*
           * Although with big capacity and small l1_entry_sectors, we can get a
           * big l1_size, we don't want unbounded value to allocate the table.
           * Limit it to 32M, which is enough to store:
           *     8TB  - for both VMDK3 & VMDK4 with
           *            minimal cluster size: 512B
           *            minimal L2 table size: 512 entries
           *            8 TB is still more than the maximal value supported for
           *            VMDK3 & VMDK4 which is 2TB.
           *     64TB - for "ESXi seSparse Extent"
           *            minimal cluster size: 512B (default is 4KB)
           *            L2 table size: 4096 entries (const).
           *            64TB is more than the maximal value supported for
           *            seSparse VMDKs (which is slightly less than 64TB)
           */
          error_setg(errp, "L1 size too big");
          return -EFBIG;
      }
  
      nb_sectors = bdrv_nb_sectors(file->bs);
      if (nb_sectors < 0) {
          return nb_sectors;
      }
  
      s->extents = g_renew(VmdkExtent, s->extents, s->num_extents + 1);
      extent = &s->extents[s->num_extents];
      s->num_extents++;
  
      memset(extent, 0, sizeof(VmdkExtent));
      extent->file = file;
      extent->flat = flat;
      extent->sectors = sectors;
      extent->l1_table_offset = l1_offset;
      extent->l1_backup_table_offset = l1_backup_offset;
      extent->l1_size = l1_size;
      extent->l1_entry_sectors = l2_size * cluster_sectors;
      extent->l2_size = l2_size;
      extent->cluster_sectors = flat ? sectors : cluster_sectors;
      extent->next_cluster_sector = ROUND_UP(nb_sectors, cluster_sectors);
      extent->entry_size = sizeof(uint32_t);
  
      if (s->num_extents > 1) {
          extent->end_sector = (*(extent - 1)).end_sector + extent->sectors;
      } else {
          extent->end_sector = extent->sectors;
      }
      bs->total_sectors = extent->end_sector;
      if (new_extent) {
          *new_extent = extent;
      }
      return 0;
  }
  
  static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                              Error **errp)
  {
      int ret;
      size_t l1_size;
      int i;
  
      /* read the L1 table */
      l1_size = extent->l1_size * extent->entry_size;
      extent->l1_table = g_try_malloc(l1_size);
      if (l1_size && extent->l1_table == NULL) {
          return -ENOMEM;
      }
  
      ret = bdrv_pread(extent->file,
                       extent->l1_table_offset,
                       extent->l1_table,
                       l1_size);
      if (ret < 0) {
          bdrv_refresh_filename(extent->file->bs);
          error_setg_errno(errp, -ret,
                           "Could not read l1 table from extent '%s'",
                           extent->file->bs->filename);
          goto fail_l1;
      }
      for (i = 0; i < extent->l1_size; i++) {
          if (extent->entry_size == sizeof(uint64_t)) {
              le64_to_cpus((uint64_t *)extent->l1_table + i);
          } else {
              assert(extent->entry_size == sizeof(uint32_t));
              le32_to_cpus((uint32_t *)extent->l1_table + i);
          }
      }
  
      if (extent->l1_backup_table_offset) {
          assert(!extent->sesparse);
          extent->l1_backup_table = g_try_malloc(l1_size);
          if (l1_size && extent->l1_backup_table == NULL) {
              ret = -ENOMEM;
              goto fail_l1;
          }
          ret = bdrv_pread(extent->file,
                           extent->l1_backup_table_offset,
                           extent->l1_backup_table,
                           l1_size);
          if (ret < 0) {
              bdrv_refresh_filename(extent->file->bs);
              error_setg_errno(errp, -ret,
                               "Could not read l1 backup table from extent '%s'",
                               extent->file->bs->filename);
              goto fail_l1b;
          }
          for (i = 0; i < extent->l1_size; i++) {
              le32_to_cpus(&extent->l1_backup_table[i]);
          }
      }
  
      extent->l2_cache =
          g_malloc(extent->entry_size * extent->l2_size * L2_CACHE_SIZE);
      return 0;
   fail_l1b:
      g_free(extent->l1_backup_table);
   fail_l1:
      g_free(extent->l1_table);
      return ret;
  }
  
  static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
                                   BdrvChild *file,
                                   int flags, Error **errp)
  {
      int ret;
      uint32_t magic;
      VMDK3Header header;
      VmdkExtent *extent = NULL;
  
      ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
      if (ret < 0) {
          bdrv_refresh_filename(file->bs);
          error_setg_errno(errp, -ret,
                           "Could not read header from file '%s'",
                           file->bs->filename);
          return ret;
      }
      ret = vmdk_add_extent(bs, file, false,
                            le32_to_cpu(header.disk_sectors),
                            (int64_t)le32_to_cpu(header.l1dir_offset) << 9,
                            0,
                            le32_to_cpu(header.l1dir_size),
                            4096,
                            le32_to_cpu(header.granularity),
                            &extent,
                            errp);
      if (ret < 0) {
          return ret;
      }
      ret = vmdk_init_tables(bs, extent, errp);
      if (ret) {
          /* free extent allocated by vmdk_add_extent */
          vmdk_free_last_extent(bs);
      }
      return ret;
  }
  
  #define SESPARSE_CONST_HEADER_MAGIC UINT64_C(0x00000000cafebabe)
  #define SESPARSE_VOLATILE_HEADER_MAGIC UINT64_C(0x00000000cafecafe)
  
  /* Strict checks - format not officially documented */
  static int check_se_sparse_const_header(VMDKSESparseConstHeader *header,
                                          Error **errp)
  {
      header->magic = le64_to_cpu(header->magic);
      header->version = le64_to_cpu(header->version);
      header->grain_size = le64_to_cpu(header->grain_size);
      header->grain_table_size = le64_to_cpu(header->grain_table_size);
      header->flags = le64_to_cpu(header->flags);
      header->reserved1 = le64_to_cpu(header->reserved1);
      header->reserved2 = le64_to_cpu(header->reserved2);
      header->reserved3 = le64_to_cpu(header->reserved3);
      header->reserved4 = le64_to_cpu(header->reserved4);
  
      header->volatile_header_offset =
          le64_to_cpu(header->volatile_header_offset);
      header->volatile_header_size = le64_to_cpu(header->volatile_header_size);
  
      header->journal_header_offset = le64_to_cpu(header->journal_header_offset);
      header->journal_header_size = le64_to_cpu(header->journal_header_size);
  
      header->journal_offset = le64_to_cpu(header->journal_offset);
      header->journal_size = le64_to_cpu(header->journal_size);
  
      header->grain_dir_offset = le64_to_cpu(header->grain_dir_offset);
      header->grain_dir_size = le64_to_cpu(header->grain_dir_size);
  
      header->grain_tables_offset = le64_to_cpu(header->grain_tables_offset);
      header->grain_tables_size = le64_to_cpu(header->grain_tables_size);
  
      header->free_bitmap_offset = le64_to_cpu(header->free_bitmap_offset);
      header->free_bitmap_size = le64_to_cpu(header->free_bitmap_size);
  
      header->backmap_offset = le64_to_cpu(header->backmap_offset);
      header->backmap_size = le64_to_cpu(header->backmap_size);
  
      header->grains_offset = le64_to_cpu(header->grains_offset);
      header->grains_size = le64_to_cpu(header->grains_size);
  
      if (header->magic != SESPARSE_CONST_HEADER_MAGIC) {
          error_setg(errp, "Bad const header magic: 0x%016" PRIx64,
                     header->magic);
          return -EINVAL;
      }
  
      if (header->version != 0x0000000200000001) {
          error_setg(errp, "Unsupported version: 0x%016" PRIx64,
                     header->version);
          return -ENOTSUP;
      }
  
      if (header->grain_size != 8) {
          error_setg(errp, "Unsupported grain size: %" PRIu64,
                     header->grain_size);
          return -ENOTSUP;
      }
  
      if (header->grain_table_size != 64) {
          error_setg(errp, "Unsupported grain table size: %" PRIu64,
                     header->grain_table_size);
          return -ENOTSUP;
      }
  
      if (header->flags != 0) {
          error_setg(errp, "Unsupported flags: 0x%016" PRIx64,
                     header->flags);
          return -ENOTSUP;
      }
  
      if (header->reserved1 != 0 || header->reserved2 != 0 ||
          header->reserved3 != 0 || header->reserved4 != 0) {
          error_setg(errp, "Unsupported reserved bits:"
                     " 0x%016" PRIx64 " 0x%016" PRIx64
                     " 0x%016" PRIx64 " 0x%016" PRIx64,
                     header->reserved1, header->reserved2,
                     header->reserved3, header->reserved4);
          return -ENOTSUP;
      }
  
      /* check that padding is 0 */
      if (!buffer_is_zero(header->pad, sizeof(header->pad))) {
          error_setg(errp, "Unsupported non-zero const header padding");
          return -ENOTSUP;
      }
  
      return 0;
  }
  
  static int check_se_sparse_volatile_header(VMDKSESparseVolatileHeader *header,
                                             Error **errp)
  {
      header->magic = le64_to_cpu(header->magic);
      header->free_gt_number = le64_to_cpu(header->free_gt_number);
      header->next_txn_seq_number = le64_to_cpu(header->next_txn_seq_number);
      header->replay_journal = le64_to_cpu(header->replay_journal);
  
      if (header->magic != SESPARSE_VOLATILE_HEADER_MAGIC) {
          error_setg(errp, "Bad volatile header magic: 0x%016" PRIx64,
                     header->magic);
          return -EINVAL;
      }
  
      if (header->replay_journal) {
          error_setg(errp, "Image is dirty, Replaying journal not supported");
          return -ENOTSUP;
      }
  
      /* check that padding is 0 */
      if (!buffer_is_zero(header->pad, sizeof(header->pad))) {
          error_setg(errp, "Unsupported non-zero volatile header padding");
          return -ENOTSUP;
      }
  
      return 0;
  }
  
  static int vmdk_open_se_sparse(BlockDriverState *bs,
                                 BdrvChild *file,
                                 int flags, Error **errp)
  {
      int ret;
      VMDKSESparseConstHeader const_header;
      VMDKSESparseVolatileHeader volatile_header;
      VmdkExtent *extent = NULL;
  
      ret = bdrv_apply_auto_read_only(bs,
              "No write support for seSparse images available", errp);
      if (ret < 0) {
          return ret;
      }
  
      assert(sizeof(const_header) == SECTOR_SIZE);
  
      ret = bdrv_pread(file, 0, &const_header, sizeof(const_header));
      if (ret < 0) {
          bdrv_refresh_filename(file->bs);
          error_setg_errno(errp, -ret,
                           "Could not read const header from file '%s'",
                           file->bs->filename);
          return ret;
      }
  
      /* check const header */
      ret = check_se_sparse_const_header(&const_header, errp);
      if (ret < 0) {
          return ret;
      }
  
      assert(sizeof(volatile_header) == SECTOR_SIZE);
  
      ret = bdrv_pread(file,
                       const_header.volatile_header_offset * SECTOR_SIZE,
                       &volatile_header, sizeof(volatile_header));
      if (ret < 0) {
          bdrv_refresh_filename(file->bs);
          error_setg_errno(errp, -ret,
                           "Could not read volatile header from file '%s'",
                           file->bs->filename);
          return ret;
      }
  
      /* check volatile header */
      ret = check_se_sparse_volatile_header(&volatile_header, errp);
      if (ret < 0) {
          return ret;
      }
  
      ret = vmdk_add_extent(bs, file, false,
                            const_header.capacity,
                            const_header.grain_dir_offset * SECTOR_SIZE,
                            0,
                            const_header.grain_dir_size *
                            SECTOR_SIZE / sizeof(uint64_t),
                            const_header.grain_table_size *
                            SECTOR_SIZE / sizeof(uint64_t),
                            const_header.grain_size,
                            &extent,
                            errp);
      if (ret < 0) {
          return ret;
      }
  
      extent->sesparse = true;
      extent->sesparse_l2_tables_offset = const_header.grain_tables_offset;
      extent->sesparse_clusters_offset = const_header.grains_offset;
      extent->entry_size = sizeof(uint64_t);
  
      ret = vmdk_init_tables(bs, extent, errp);
      if (ret) {
          /* free extent allocated by vmdk_add_extent */
          vmdk_free_last_extent(bs);
      }
  
      return ret;
  }
  
  static int vmdk_open_desc_file(BlockDriverState *bs, int flags, char *buf,
                                 QDict *options, Error **errp);
  
  static char *vmdk_read_desc(BdrvChild *file, uint64_t desc_offset, Error **errp)
  {
      int64_t size;
      char *buf;
      int ret;
  
      size = bdrv_getlength(file->bs);
      if (size < 0) {
          error_setg_errno(errp, -size, "Could not access file");
          return NULL;
      }
  
      if (size < 4) {
          /* Both descriptor file and sparse image must be much larger than 4
           * bytes, also callers of vmdk_read_desc want to compare the first 4
           * bytes with VMDK4_MAGIC, let's error out if less is read. */
          error_setg(errp, "File is too small, not a valid image");
          return NULL;
      }
  
      size = MIN(size, (1 << 20) - 1);  /* avoid unbounded allocation */
      buf = g_malloc(size + 1);
  
      ret = bdrv_pread(file, desc_offset, buf, size);
      if (ret < 0) {
          error_setg_errno(errp, -ret, "Could not read from file");
          g_free(buf);
          return NULL;
      }
      buf[ret] = 0;
  
      return buf;
  }
  
  static int vmdk_open_vmdk4(BlockDriverState *bs,
                             BdrvChild *file,
                             int flags, QDict *options, Error **errp)
  {
      int ret;
      uint32_t magic;
      uint32_t l1_size, l1_entry_sectors;
      VMDK4Header header;
      VmdkExtent *extent = NULL;
      BDRVVmdkState *s = bs->opaque;
      int64_t l1_backup_offset = 0;
      bool compressed;
  
      ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
      if (ret < 0) {
          bdrv_refresh_filename(file->bs);
          error_setg_errno(errp, -ret,
                           "Could not read header from file '%s'",
                           file->bs->filename);
          return -EINVAL;
      }
      if (header.capacity == 0) {
          uint64_t desc_offset = le64_to_cpu(header.desc_offset);
          if (desc_offset) {
              char *buf = vmdk_read_desc(file, desc_offset << 9, errp);
              if (!buf) {
                  return -EINVAL;
              }
              ret = vmdk_open_desc_file(bs, flags, buf, options, errp);
              g_free(buf);
              return ret;
          }
      }
  
      if (!s->create_type) {
          s->create_type = g_strdup("monolithicSparse");
      }
  
      if (le64_to_cpu(header.gd_offset) == VMDK4_GD_AT_END) {
          /*
           * The footer takes precedence over the header, so read it in. The
           * footer starts at offset -1024 from the end: One sector for the
           * footer, and another one for the end-of-stream marker.
           */
          struct {
              struct {
                  uint64_t val;
                  uint32_t size;
                  uint32_t type;
                  uint8_t pad[512 - 16];
              } QEMU_PACKED footer_marker;
  
              uint32_t magic;
              VMDK4Header header;
              uint8_t pad[512 - 4 - sizeof(VMDK4Header)];
  
              struct {
                  uint64_t val;
                  uint32_t size;
                  uint32_t type;
                  uint8_t pad[512 - 16];
              } QEMU_PACKED eos_marker;
          } QEMU_PACKED footer;
  
          ret = bdrv_pread(file,
              bs->file->bs->total_sectors * 512 - 1536,
              &footer, sizeof(footer));
          if (ret < 0) {
              error_setg_errno(errp, -ret, "Failed to read footer");
              return ret;
          }
  
          /* Some sanity checks for the footer */
          if (be32_to_cpu(footer.magic) != VMDK4_MAGIC ||
              le32_to_cpu(footer.footer_marker.size) != 0  ||
              le32_to_cpu(footer.footer_marker.type) != MARKER_FOOTER ||
              le64_to_cpu(footer.eos_marker.val) != 0  ||
              le32_to_cpu(footer.eos_marker.size) != 0  ||
              le32_to_cpu(footer.eos_marker.type) != MARKER_END_OF_STREAM)
          {
              error_setg(errp, "Invalid footer");
              return -EINVAL;
          }
  
          header = footer.header;
      }
  
      compressed =
          le16_to_cpu(header.compressAlgorithm) == VMDK4_COMPRESSION_DEFLATE;
      if (le32_to_cpu(header.version) > 3) {
          error_setg(errp, "Unsupported VMDK version %" PRIu32,
                     le32_to_cpu(header.version));
          return -ENOTSUP;
      } else if (le32_to_cpu(header.version) == 3 && (flags & BDRV_O_RDWR) &&
                 !compressed) {
          /* VMware KB 2064959 explains that version 3 added support for
           * persistent changed block tracking (CBT), and backup software can
           * read it as version=1 if it doesn't care about the changed area
           * information. So we are safe to enable read only. */
          error_setg(errp, "VMDK version 3 must be read only");
          return -EINVAL;
      }
  
      if (le32_to_cpu(header.num_gtes_per_gt) > 512) {
          error_setg(errp, "L2 table size too big");
          return -EINVAL;
      }
  
      l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gt)
                          * le64_to_cpu(header.granularity);
      if (l1_entry_sectors == 0) {
          error_setg(errp, "L1 entry size is invalid");
          return -EINVAL;
      }
      l1_size = (le64_to_cpu(header.capacity) + l1_entry_sectors - 1)
                  / l1_entry_sectors;
      if (le32_to_cpu(header.flags) & VMDK4_FLAG_RGD) {
          l1_backup_offset = le64_to_cpu(header.rgd_offset) << 9;
      }
      if (bdrv_nb_sectors(file->bs) < le64_to_cpu(header.grain_offset)) {
          error_setg(errp, "File truncated, expecting at least %" PRId64 " bytes",
                     (int64_t)(le64_to_cpu(header.grain_offset)
                               * BDRV_SECTOR_SIZE));
          return -EINVAL;
      }
  
      ret = vmdk_add_extent(bs, file, false,
                            le64_to_cpu(header.capacity),
                            le64_to_cpu(header.gd_offset) << 9,
                            l1_backup_offset,
                            l1_size,
                            le32_to_cpu(header.num_gtes_per_gt),
                            le64_to_cpu(header.granularity),
                            &extent,
                            errp);
      if (ret < 0) {
          return ret;
      }
      extent->compressed =
          le16_to_cpu(header.compressAlgorithm) == VMDK4_COMPRESSION_DEFLATE;
      if (extent->compressed) {
          g_free(s->create_type);
          s->create_type = g_strdup("streamOptimized");
      }
      extent->has_marker = le32_to_cpu(header.flags) & VMDK4_FLAG_MARKER;
      extent->version = le32_to_cpu(header.version);
      extent->has_zero_grain = le32_to_cpu(header.flags) & VMDK4_FLAG_ZERO_GRAIN;
      ret = vmdk_init_tables(bs, extent, errp);
      if (ret) {
          /* free extent allocated by vmdk_add_extent */
          vmdk_free_last_extent(bs);
      }
      return ret;
  }
  
  /* find an option value out of descriptor file */
  static int vmdk_parse_description(const char *desc, const char *opt_name,
          char *buf, int buf_size)
  {
      char *opt_pos, *opt_end;
      const char *end = desc + strlen(desc);
  
      opt_pos = strstr(desc, opt_name);
      if (!opt_pos) {
          return VMDK_ERROR;
      }
      /* Skip "=\"" following opt_name */
      opt_pos += strlen(opt_name) + 2;
      if (opt_pos >= end) {
          return VMDK_ERROR;
      }
      opt_end = opt_pos;
      while (opt_end < end && *opt_end != '"') {
          opt_end++;
      }
      if (opt_end == end || buf_size < opt_end - opt_pos + 1) {
          return VMDK_ERROR;
      }
      pstrcpy(buf, opt_end - opt_pos + 1, opt_pos);
      return VMDK_OK;
  }
  
  /* Open an extent file and append to bs array */
  static int vmdk_open_sparse(BlockDriverState *bs, BdrvChild *file, int flags,
                              char *buf, QDict *options, Error **errp)
  {
      uint32_t magic;
  
      magic = ldl_be_p(buf);
      switch (magic) {
          case VMDK3_MAGIC:
              return vmdk_open_vmfs_sparse(bs, file, flags, errp);
          case VMDK4_MAGIC:
              return vmdk_open_vmdk4(bs, file, flags, options, errp);
          default:
              error_setg(errp, "Image not in VMDK format");
              return -EINVAL;
      }
  }
  
  static const char *next_line(const char *s)
  {
      while (*s) {
          if (*s == '\n') {
              return s + 1;
          }
          s++;
      }
      return s;
  }
  
  static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
                                QDict *options, Error **errp)
  {
      int ret;
      int matches;
      char access[11];
      char type[11];
      char fname[512];
      const char *p, *np;
      int64_t sectors = 0;
      int64_t flat_offset;
      char *desc_file_dir = NULL;
      char *extent_path;
      BdrvChild *extent_file;
      BdrvChildRole extent_role;
      BDRVVmdkState *s = bs->opaque;
      VmdkExtent *extent = NULL;
      char extent_opt_prefix[32];
      Error *local_err = NULL;
  
      for (p = desc; *p; p = next_line(p)) {
          /* parse extent line in one of below formats:
           *
           * RW [size in sectors] FLAT "file-name.vmdk" OFFSET
           * RW [size in sectors] SPARSE "file-name.vmdk"
           * RW [size in sectors] VMFS "file-name.vmdk"
           * RW [size in sectors] VMFSSPARSE "file-name.vmdk"
           * RW [size in sectors] SESPARSE "file-name.vmdk"
           */
          flat_offset = -1;
          matches = sscanf(p, "%10s %" SCNd64 " %10s \"%511[^\n\r\"]\" %" SCNd64,
                           access, &sectors, type, fname, &flat_offset);
          if (matches < 4 || strcmp(access, "RW")) {
              continue;
          } else if (!strcmp(type, "FLAT")) {
              if (matches != 5 || flat_offset < 0) {
                  goto invalid;
              }
          } else if (!strcmp(type, "VMFS")) {
              if (matches == 4) {
                  flat_offset = 0;
              } else {
                  goto invalid;
              }
          } else if (matches != 4) {
              goto invalid;
          }
  
          if (sectors <= 0 ||
              (strcmp(type, "FLAT") && strcmp(type, "SPARSE") &&
               strcmp(type, "VMFS") && strcmp(type, "VMFSSPARSE") &&
               strcmp(type, "SESPARSE")) ||
              (strcmp(access, "RW"))) {
              continue;
          }
  
          if (path_is_absolute(fname)) {
              extent_path = g_strdup(fname);
          } else {
              if (!desc_file_dir) {
                  desc_file_dir = bdrv_dirname(bs->file->bs, errp);
                  if (!desc_file_dir) {
                      bdrv_refresh_filename(bs->file->bs);
                      error_prepend(errp, "Cannot use relative paths with VMDK "
                                    "descriptor file '%s': ",
                                    bs->file->bs->filename);
                      ret = -EINVAL;
                      goto out;
                  }
              }
  
              extent_path = g_strconcat(desc_file_dir, fname, NULL);
          }
  
          ret = snprintf(extent_opt_prefix, 32, "extents.%d", s->num_extents);
          assert(ret < 32);
  
          extent_role = BDRV_CHILD_DATA;
          if (strcmp(type, "FLAT") != 0 && strcmp(type, "VMFS") != 0) {
              /* non-flat extents have metadata */
              extent_role |= BDRV_CHILD_METADATA;
          }
  
          extent_file = bdrv_open_child(extent_path, options, extent_opt_prefix,
                                        bs, &child_of_bds, extent_role, false,
                                        &local_err);
          g_free(extent_path);
          if (local_err) {
              error_propagate(errp, local_err);
              ret = -EINVAL;
              goto out;
          }
  
          /* save to extents array */
          if (!strcmp(type, "FLAT") || !strcmp(type, "VMFS")) {
              /* FLAT extent */
  
              ret = vmdk_add_extent(bs, extent_file, true, sectors,
                              0, 0, 0, 0, 0, &extent, errp);
              if (ret < 0) {
                  bdrv_unref_child(bs, extent_file);
                  goto out;
              }
              extent->flat_start_offset = flat_offset << 9;
          } else if (!strcmp(type, "SPARSE") || !strcmp(type, "VMFSSPARSE")) {
              /* SPARSE extent and VMFSSPARSE extent are both "COWD" sparse file*/
              char *buf = vmdk_read_desc(extent_file, 0, errp);
              if (!buf) {
                  ret = -EINVAL;
              } else {
                  ret = vmdk_open_sparse(bs, extent_file, bs->open_flags, buf,
                                         options, errp);
              }
              g_free(buf);
              if (ret) {
                  bdrv_unref_child(bs, extent_file);
                  goto out;
              }
              extent = &s->extents[s->num_extents - 1];
          } else if (!strcmp(type, "SESPARSE")) {
              ret = vmdk_open_se_sparse(bs, extent_file, bs->open_flags, errp);
              if (ret) {
                  bdrv_unref_child(bs, extent_file);
                  goto out;
              }
              extent = &s->extents[s->num_extents - 1];
          } else {
              error_setg(errp, "Unsupported extent type '%s'", type);
              bdrv_unref_child(bs, extent_file);
              ret = -ENOTSUP;
              goto out;
          }
          extent->type = g_strdup(type);
      }
  
      ret = 0;
      goto out;
  
  invalid:
      np = next_line(p);
      assert(np != p);
      if (np[-1] == '\n') {
          np--;
      }
      error_setg(errp, "Invalid extent line: %.*s", (int)(np - p), p);
      ret = -EINVAL;
  
  out:
      g_free(desc_file_dir);
      return ret;
  }
  
  static int vmdk_open_desc_file(BlockDriverState *bs, int flags, char *buf,
                                 QDict *options, Error **errp)
  {
      int ret;
      char ct[128];
      BDRVVmdkState *s = bs->opaque;
  
      if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
          error_setg(errp, "invalid VMDK image descriptor");
          ret = -EINVAL;
          goto exit;
      }
      if (strcmp(ct, "monolithicFlat") &&
          strcmp(ct, "vmfs") &&
          strcmp(ct, "vmfsSparse") &&
          strcmp(ct, "seSparse") &&
          strcmp(ct, "twoGbMaxExtentSparse") &&
          strcmp(ct, "twoGbMaxExtentFlat")) {
          error_setg(errp, "Unsupported image type '%s'", ct);
          ret = -ENOTSUP;
          goto exit;
      }
      s->create_type = g_strdup(ct);
      s->desc_offset = 0;
      ret = vmdk_parse_extents(buf, bs, options, errp);
  exit:
      return ret;
  }
  
  static int vmdk_open(BlockDriverState *bs, QDict *options, int flags,
                       Error **errp)
  {
      char *buf;
      int ret;
      BDRVVmdkState *s = bs->opaque;
      uint32_t magic;
  
      bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
                                 BDRV_CHILD_IMAGE, false, errp);
      if (!bs->file) {
          return -EINVAL;
      }
  
      buf = vmdk_read_desc(bs->file, 0, errp);
      if (!buf) {
          return -EINVAL;
      }
  
      magic = ldl_be_p(buf);
      switch (magic) {
          case VMDK3_MAGIC:
          case VMDK4_MAGIC:
              ret = vmdk_open_sparse(bs, bs->file, flags, buf, options,
                                     errp);
              s->desc_offset = 0x200;
              break;
          default:
              /* No data in the descriptor file */
              bs->file->role &= ~BDRV_CHILD_DATA;
  
              /* Must succeed because we have given up permissions if anything */
              bdrv_child_refresh_perms(bs, bs->file, &error_abort);
  
              ret = vmdk_open_desc_file(bs, flags, buf, options, errp);
              break;
      }
      if (ret) {
          goto fail;
      }
  
      /* try to open parent images, if exist */
      ret = vmdk_parent_open(bs);
      if (ret) {
          goto fail;
      }
      ret = vmdk_read_cid(bs, 0, &s->cid);
      if (ret) {
          goto fail;
      }
      ret = vmdk_read_cid(bs, 1, &s->parent_cid);
      if (ret) {
          goto fail;
      }
      qemu_co_mutex_init(&s->lock);
  
      /* Disable migration when VMDK images are used */
      error_setg(&s->migration_blocker, "The vmdk format used by node '%s' "
                 "does not support live migration",
                 bdrv_get_device_or_node_name(bs));
      ret = migrate_add_blocker(s->migration_blocker, errp);
      if (ret < 0) {
          error_free(s->migration_blocker);
          goto fail;
      }
  
      g_free(buf);
      return 0;
  
  fail:
      g_free(buf);
      g_free(s->create_type);
      s->create_type = NULL;
      vmdk_free_extents(bs);
      return ret;
  }
  
  
  static void vmdk_refresh_limits(BlockDriverState *bs, Error **errp)
  {
      BDRVVmdkState *s = bs->opaque;
      int i;
  
      for (i = 0; i < s->num_extents; i++) {
          if (!s->extents[i].flat) {
              bs->bl.pwrite_zeroes_alignment =
                  MAX(bs->bl.pwrite_zeroes_alignment,
                      s->extents[i].cluster_sectors << BDRV_SECTOR_BITS);
          }
      }
  }
  
  /**
   * get_whole_cluster
   *
   * Copy backing file's cluster that covers @sector_num, otherwise write zero,
   * to the cluster at @cluster_sector_num. If @zeroed is true, we're overwriting
   * a zeroed cluster in the current layer and must not copy data from the
   * backing file.
   *
   * If @skip_start_sector < @skip_end_sector, the relative range
   * [@skip_start_sector, @skip_end_sector) is not copied or written, and leave
   * it for call to write user data in the request.
   */
  static int get_whole_cluster(BlockDriverState *bs,
                               VmdkExtent *extent,
                               uint64_t cluster_offset,
                               uint64_t offset,
                               uint64_t skip_start_bytes,
                               uint64_t skip_end_bytes,
                               bool zeroed)
  {
      int ret = VMDK_OK;
      int64_t cluster_bytes;
      uint8_t *whole_grain;
      bool copy_from_backing;
  
      /* For COW, align request sector_num to cluster start */
      cluster_bytes = extent->cluster_sectors << BDRV_SECTOR_BITS;
      offset = QEMU_ALIGN_DOWN(offset, cluster_bytes);
      whole_grain = qemu_blockalign(bs, cluster_bytes);
      copy_from_backing = bs->backing && !zeroed;
  
      if (!copy_from_backing) {
          memset(whole_grain, 0, skip_start_bytes);
          memset(whole_grain + skip_end_bytes, 0, cluster_bytes - skip_end_bytes);
      }
  
      assert(skip_end_bytes <= cluster_bytes);
      /* we will be here if it's first write on non-exist grain(cluster).
       * try to read from parent image, if exist */
      if (bs->backing && !vmdk_is_cid_valid(bs)) {
          ret = VMDK_ERROR;
          goto exit;
      }
  
      /* Read backing data before skip range */
      if (skip_start_bytes > 0) {
          if (copy_from_backing) {
              /* qcow2 emits this on bs->file instead of bs->backing */
              BLKDBG_EVENT(extent->file, BLKDBG_COW_READ);
              ret = bdrv_pread(bs->backing, offset, whole_grain,
                               skip_start_bytes);
              if (ret < 0) {
                  ret = VMDK_ERROR;
                  goto exit;
              }
          }
          BLKDBG_EVENT(extent->file, BLKDBG_COW_WRITE);
          ret = bdrv_pwrite(extent->file, cluster_offset, whole_grain,
                            skip_start_bytes);
          if (ret < 0) {
              ret = VMDK_ERROR;
              goto exit;
          }
      }
      /* Read backing data after skip range */
      if (skip_end_bytes < cluster_bytes) {
          if (copy_from_backing) {
              /* qcow2 emits this on bs->file instead of bs->backing */
              BLKDBG_EVENT(extent->file, BLKDBG_COW_READ);
              ret = bdrv_pread(bs->backing, offset + skip_end_bytes,
                               whole_grain + skip_end_bytes,
                               cluster_bytes - skip_end_bytes);
              if (ret < 0) {
                  ret = VMDK_ERROR;
                  goto exit;
              }
          }
          BLKDBG_EVENT(extent->file, BLKDBG_COW_WRITE);
          ret = bdrv_pwrite(extent->file, cluster_offset + skip_end_bytes,
                            whole_grain + skip_end_bytes,
                            cluster_bytes - skip_end_bytes);
          if (ret < 0) {
              ret = VMDK_ERROR;
              goto exit;
          }
      }
  
      ret = VMDK_OK;
  exit:
      qemu_vfree(whole_grain);
      return ret;
  }
  
  static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data,
                           uint32_t offset)
  {
      offset = cpu_to_le32(offset);
      /* update L2 table */
      BLKDBG_EVENT(extent->file, BLKDBG_L2_UPDATE);
      if (bdrv_pwrite(extent->file,
                  ((int64_t)m_data->l2_offset * 512)
                      + (m_data->l2_index * sizeof(offset)),
                  &offset, sizeof(offset)) < 0) {
          return VMDK_ERROR;
      }
      /* update backup L2 table */
      if (extent->l1_backup_table_offset != 0) {
          m_data->l2_offset = extent->l1_backup_table[m_data->l1_index];
          if (bdrv_pwrite(extent->file,
                      ((int64_t)m_data->l2_offset * 512)
                          + (m_data->l2_index * sizeof(offset)),
                      &offset, sizeof(offset)) < 0) {
              return VMDK_ERROR;
          }
      }
      if (bdrv_flush(extent->file->bs) < 0) {
          return VMDK_ERROR;
      }
      if (m_data->l2_cache_entry) {
          *m_data->l2_cache_entry = offset;
      }
  
      return VMDK_OK;
  }
  
  /**
   * get_cluster_offset
   *
   * Look up cluster offset in extent file by sector number, and store in
   * @cluster_offset.
   *
   * For flat extents, the start offset as parsed from the description file is
   * returned.
   *
   * For sparse extents, look up in L1, L2 table. If allocate is true, return an
   * offset for a new cluster and update L2 cache. If there is a backing file,
   * COW is done before returning; otherwise, zeroes are written to the allocated
   * cluster. Both COW and zero writing skips the sector range
   * [@skip_start_sector, @skip_end_sector) passed in by caller, because caller
   * has new data to write there.
   *
   * Returns: VMDK_OK if cluster exists and mapped in the image.
   *          VMDK_UNALLOC if cluster is not mapped and @allocate is false.
   *          VMDK_ERROR if failed.
   */
  static int get_cluster_offset(BlockDriverState *bs,
                                VmdkExtent *extent,
                                VmdkMetaData *m_data,
                                uint64_t offset,
                                bool allocate,
                                uint64_t *cluster_offset,
                                uint64_t skip_start_bytes,
                                uint64_t skip_end_bytes)
  {
      unsigned int l1_index, l2_offset, l2_index;
      int min_index, i, j;
      uint32_t min_count;
      void *l2_table;
      bool zeroed = false;
      int64_t ret;
      int64_t cluster_sector;
      unsigned int l2_size_bytes = extent->l2_size * extent->entry_size;
  
      if (m_data) {
          m_data->new_allocation = false;
      }
      if (extent->flat) {
          *cluster_offset = extent->flat_start_offset;
          return VMDK_OK;
      }
  
      offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE;
      l1_index = (offset >> 9) / extent->l1_entry_sectors;
      if (l1_index >= extent->l1_size) {
          return VMDK_ERROR;
      }
      if (extent->sesparse) {
          uint64_t l2_offset_u64;
  
          assert(extent->entry_size == sizeof(uint64_t));
  
          l2_offset_u64 = ((uint64_t *)extent->l1_table)[l1_index];
          if (l2_offset_u64 == 0) {
              l2_offset = 0;
          } else if ((l2_offset_u64 & 0xffffffff00000000) != 0x1000000000000000) {
              /*
               * Top most nibble is 0x1 if grain table is allocated.
               * strict check - top most 4 bytes must be 0x10000000 since max
               * supported size is 64TB for disk - so no more than 64TB / 16MB
               * grain directories which is smaller than uint32,
               * where 16MB is the only supported default grain table coverage.
               */
              return VMDK_ERROR;
          } else {
              l2_offset_u64 = l2_offset_u64 & 0x00000000ffffffff;
              l2_offset_u64 = extent->sesparse_l2_tables_offset +
                  l2_offset_u64 * l2_size_bytes / SECTOR_SIZE;
              if (l2_offset_u64 > 0x00000000ffffffff) {
                  return VMDK_ERROR;
              }
              l2_offset = (unsigned int)(l2_offset_u64);
          }
      } else {
          assert(extent->entry_size == sizeof(uint32_t));
          l2_offset = ((uint32_t *)extent->l1_table)[l1_index];
      }
      if (!l2_offset) {
          return VMDK_UNALLOC;
      }
      for (i = 0; i < L2_CACHE_SIZE; i++) {
          if (l2_offset == extent->l2_cache_offsets[i]) {
              /* increment the hit count */
              if (++extent->l2_cache_counts[i] == 0xffffffff) {
                  for (j = 0; j < L2_CACHE_SIZE; j++) {
                      extent->l2_cache_counts[j] >>= 1;
                  }
              }
              l2_table = (char *)extent->l2_cache + (i * l2_size_bytes);
              goto found;
          }
      }
      /* not found: load a new entry in the least used one */
      min_index = 0;
      min_count = 0xffffffff;
      for (i = 0; i < L2_CACHE_SIZE; i++) {
          if (extent->l2_cache_counts[i] < min_count) {
              min_count = extent->l2_cache_counts[i];
              min_index = i;
          }
      }
      l2_table = (char *)extent->l2_cache + (min_index * l2_size_bytes);
      BLKDBG_EVENT(extent->file, BLKDBG_L2_LOAD);
      if (bdrv_pread(extent->file,
                  (int64_t)l2_offset * 512,
                  l2_table,
                  l2_size_bytes
              ) != l2_size_bytes) {
          return VMDK_ERROR;
      }
  
      extent->l2_cache_offsets[min_index] = l2_offset;
      extent->l2_cache_counts[min_index] = 1;
   found:
      l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size;
      if (m_data) {
          m_data->l1_index = l1_index;
          m_data->l2_index = l2_index;
          m_data->l2_offset = l2_offset;
          m_data->l2_cache_entry = ((uint32_t *)l2_table) + l2_index;
      }
  
      if (extent->sesparse) {
          cluster_sector = le64_to_cpu(((uint64_t *)l2_table)[l2_index]);
          switch (cluster_sector & 0xf000000000000000) {
          case 0x0000000000000000:
              /* unallocated grain */
              if (cluster_sector != 0) {
                  return VMDK_ERROR;
              }
              break;
          case 0x1000000000000000:
              /* scsi-unmapped grain - fallthrough */
          case 0x2000000000000000:
              /* zero grain */
              zeroed = true;
              break;
          case 0x3000000000000000:
              /* allocated grain */
              cluster_sector = (((cluster_sector & 0x0fff000000000000) >> 48) |
                                ((cluster_sector & 0x0000ffffffffffff) << 12));
              cluster_sector = extent->sesparse_clusters_offset +
                  cluster_sector * extent->cluster_sectors;
              break;
          default:
              return VMDK_ERROR;
          }
      } else {
          cluster_sector = le32_to_cpu(((uint32_t *)l2_table)[l2_index]);
  
          if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) {
              zeroed = true;
          }
      }
  
      if (!cluster_sector || zeroed) {
          if (!allocate) {
              return zeroed ? VMDK_ZEROED : VMDK_UNALLOC;
          }
          assert(!extent->sesparse);
  
          if (extent->next_cluster_sector >= VMDK_EXTENT_MAX_SECTORS) {
              return VMDK_ERROR;
          }
  
          cluster_sector = extent->next_cluster_sector;
          extent->next_cluster_sector += extent->cluster_sectors;
  
          /* First of all we write grain itself, to avoid race condition
           * that may to corrupt the image.
           * This problem may occur because of insufficient space on host disk
           * or inappropriate VM shutdown.
           */
          ret = get_whole_cluster(bs, extent, cluster_sector * BDRV_SECTOR_SIZE,
                                  offset, skip_start_bytes, skip_end_bytes,
                                  zeroed);
          if (ret) {
              return ret;
          }
          if (m_data) {
              m_data->new_allocation = true;
          }
      }
      *cluster_offset = cluster_sector << BDRV_SECTOR_BITS;
      return VMDK_OK;
  }
  
  static VmdkExtent *find_extent(BDRVVmdkState *s,
                                  int64_t sector_num, VmdkExtent *start_hint)
  {
      VmdkExtent *extent = start_hint;
  
      if (!extent) {
          extent = &s->extents[0];
      }
      while (extent < &s->extents[s->num_extents]) {
          if (sector_num < extent->end_sector) {
              return extent;
          }
          extent++;
      }
      return NULL;
  }
  
  static inline uint64_t vmdk_find_offset_in_cluster(VmdkExtent *extent,
                                                     int64_t offset)
  {
      uint64_t extent_begin_offset, extent_relative_offset;
      uint64_t cluster_size = extent->cluster_sectors * BDRV_SECTOR_SIZE;
  
      extent_begin_offset =
          (extent->end_sector - extent->sectors) * BDRV_SECTOR_SIZE;
      extent_relative_offset = offset - extent_begin_offset;
      return extent_relative_offset % cluster_size;
  }
  
  static int coroutine_fn vmdk_co_block_status(BlockDriverState *bs,
                                               bool want_zero,
                                               int64_t offset, int64_t bytes,
                                               int64_t *pnum, int64_t *map,
                                               BlockDriverState **file)
  {
      BDRVVmdkState *s = bs->opaque;
      int64_t index_in_cluster, n, ret;
      uint64_t cluster_offset;
      VmdkExtent *extent;
  
      extent = find_extent(s, offset >> BDRV_SECTOR_BITS, NULL);
      if (!extent) {
          return -EIO;
      }
      qemu_co_mutex_lock(&s->lock);
      ret = get_cluster_offset(bs, extent, NULL, offset, false, &cluster_offset,
                               0, 0);
      qemu_co_mutex_unlock(&s->lock);
  
      index_in_cluster = vmdk_find_offset_in_cluster(extent, offset);
      switch (ret) {
      case VMDK_ERROR:
          ret = -EIO;
          break;
      case VMDK_UNALLOC:
          ret = 0;
          break;
      case VMDK_ZEROED:
          ret = BDRV_BLOCK_ZERO;
          break;
      case VMDK_OK:
          ret = BDRV_BLOCK_DATA;
          if (!extent->compressed) {
              ret |= BDRV_BLOCK_OFFSET_VALID;
              *map = cluster_offset + index_in_cluster;
              if (extent->flat) {
                  ret |= BDRV_BLOCK_RECURSE;
              }
          }
          *file = extent->file->bs;
          break;
      }
  
      n = extent->cluster_sectors * BDRV_SECTOR_SIZE - index_in_cluster;
      *pnum = MIN(n, bytes);
      return ret;
  }
  
  static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
                              int64_t offset_in_cluster, QEMUIOVector *qiov,
                              uint64_t qiov_offset, uint64_t n_bytes,
                              uint64_t offset)
  {
      int ret;
      VmdkGrainMarker *data = NULL;
      uLongf buf_len;
      QEMUIOVector local_qiov;
      int64_t write_offset;
      int64_t write_end_sector;
  
      if (extent->compressed) {
          void *compressed_data;
  
          /* Only whole clusters */
          if (offset_in_cluster ||
              n_bytes > (extent->cluster_sectors * SECTOR_SIZE) ||
              (n_bytes < (extent->cluster_sectors * SECTOR_SIZE) &&
               offset + n_bytes != extent->end_sector * SECTOR_SIZE))
          {
              ret = -EINVAL;
              goto out;
          }
  
          if (!extent->has_marker) {
              ret = -EINVAL;
              goto out;
          }
          buf_len = (extent->cluster_sectors << 9) * 2;
          data = g_malloc(buf_len + sizeof(VmdkGrainMarker));
  
          compressed_data = g_malloc(n_bytes);
          qemu_iovec_to_buf(qiov, qiov_offset, compressed_data, n_bytes);
          ret = compress(data->data, &buf_len, compressed_data, n_bytes);
          g_free(compressed_data);
  
          if (ret != Z_OK || buf_len == 0) {
              ret = -EINVAL;
              goto out;
          }
  
          data->lba = cpu_to_le64(offset >> BDRV_SECTOR_BITS);
          data->size = cpu_to_le32(buf_len);
  
          n_bytes = buf_len + sizeof(VmdkGrainMarker);
          qemu_iovec_init_buf(&local_qiov, data, n_bytes);
  
          BLKDBG_EVENT(extent->file, BLKDBG_WRITE_COMPRESSED);
      } else {
          qemu_iovec_init(&local_qiov, qiov->niov);
          qemu_iovec_concat(&local_qiov, qiov, qiov_offset, n_bytes);
  
          BLKDBG_EVENT(extent->file, BLKDBG_WRITE_AIO);
      }
  
      write_offset = cluster_offset + offset_in_cluster;
      ret = bdrv_co_pwritev(extent->file, write_offset, n_bytes,
                            &local_qiov, 0);
  
      write_end_sector = DIV_ROUND_UP(write_offset + n_bytes, BDRV_SECTOR_SIZE);
  
      if (extent->compressed) {
          extent->next_cluster_sector = write_end_sector;
      } else {
          extent->next_cluster_sector = MAX(extent->next_cluster_sector,
                                            write_end_sector);
      }
  
      if (ret < 0) {
          goto out;
      }
      ret = 0;
   out:
      g_free(data);
      if (!extent->compressed) {
          qemu_iovec_destroy(&local_qiov);
      }
      return ret;
  }
  
  static int vmdk_read_extent(VmdkExtent *extent, int64_t cluster_offset,
                              int64_t offset_in_cluster, QEMUIOVector *qiov,
                              int bytes)
  {
      int ret;
      int cluster_bytes, buf_bytes;
      uint8_t *cluster_buf, *compressed_data;
      uint8_t *uncomp_buf;
      uint32_t data_len;
      VmdkGrainMarker *marker;
      uLongf buf_len;
  
  
      if (!extent->compressed) {
          BLKDBG_EVENT(extent->file, BLKDBG_READ_AIO);
          ret = bdrv_co_preadv(extent->file,
                               cluster_offset + offset_in_cluster, bytes,
                               qiov, 0);
          if (ret < 0) {
              return ret;
          }
          return 0;
      }
      cluster_bytes = extent->cluster_sectors * 512;
      /* Read two clusters in case GrainMarker + compressed data > one cluster */
      buf_bytes = cluster_bytes * 2;
      cluster_buf = g_malloc(buf_bytes);
      uncomp_buf = g_malloc(cluster_bytes);
      BLKDBG_EVENT(extent->file, BLKDBG_READ_COMPRESSED);
      ret = bdrv_pread(extent->file,
                  cluster_offset,
                  cluster_buf, buf_bytes);
      if (ret < 0) {
          goto out;
      }
      compressed_data = cluster_buf;
      buf_len = cluster_bytes;
      data_len = cluster_bytes;
      if (extent->has_marker) {
          marker = (VmdkGrainMarker *)cluster_buf;
          compressed_data = marker->data;
          data_len = le32_to_cpu(marker->size);
      }
      if (!data_len || data_len > buf_bytes) {
          ret = -EINVAL;
          goto out;
      }
      ret = uncompress(uncomp_buf, &buf_len, compressed_data, data_len);
      if (ret != Z_OK) {
          ret = -EINVAL;
          goto out;
  
      }
      if (offset_in_cluster < 0 ||
              offset_in_cluster + bytes > buf_len) {
          ret = -EINVAL;
          goto out;
      }
      qemu_iovec_from_buf(qiov, 0, uncomp_buf + offset_in_cluster, bytes);
      ret = 0;
  
   out:
      g_free(uncomp_buf);
      g_free(cluster_buf);
      return ret;
  }
  
  static int coroutine_fn
  vmdk_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                 QEMUIOVector *qiov, int flags)
  {
      BDRVVmdkState *s = bs->opaque;
      int ret;
      uint64_t n_bytes, offset_in_cluster;
      VmdkExtent *extent = NULL;
      QEMUIOVector local_qiov;
      uint64_t cluster_offset;
      uint64_t bytes_done = 0;
  
      qemu_iovec_init(&local_qiov, qiov->niov);
      qemu_co_mutex_lock(&s->lock);
  
      while (bytes > 0) {
          extent = find_extent(s, offset >> BDRV_SECTOR_BITS, extent);
          if (!extent) {
              ret = -EIO;
              goto fail;
          }
          ret = get_cluster_offset(bs, extent, NULL,
                                   offset, false, &cluster_offset, 0, 0);
          offset_in_cluster = vmdk_find_offset_in_cluster(extent, offset);
  
          n_bytes = MIN(bytes, extent->cluster_sectors * BDRV_SECTOR_SIZE
                               - offset_in_cluster);
  
          if (ret != VMDK_OK) {
              /* if not allocated, try to read from parent image, if exist */
              if (bs->backing && ret != VMDK_ZEROED) {
                  if (!vmdk_is_cid_valid(bs)) {
                      ret = -EINVAL;
                      goto fail;
                  }
  
                  qemu_iovec_reset(&local_qiov);
                  qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes);
  
                  /* qcow2 emits this on bs->file instead of bs->backing */
                  BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
                  ret = bdrv_co_preadv(bs->backing, offset, n_bytes,
                                       &local_qiov, 0);
                  if (ret < 0) {
                      goto fail;
                  }
              } else {
                  qemu_iovec_memset(qiov, bytes_done, 0, n_bytes);
              }
          } else {
              qemu_iovec_reset(&local_qiov);
              qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes);
  
              ret = vmdk_read_extent(extent, cluster_offset, offset_in_cluster,
                                     &local_qiov, n_bytes);
              if (ret) {
                  goto fail;
              }
          }
          bytes -= n_bytes;
          offset += n_bytes;
          bytes_done += n_bytes;
      }
  
      ret = 0;
  fail:
      qemu_co_mutex_unlock(&s->lock);
      qemu_iovec_destroy(&local_qiov);
  
      return ret;
  }
  
  /**
   * vmdk_write:
   * @zeroed:       buf is ignored (data is zero), use zeroed_grain GTE feature
   *                if possible, otherwise return -ENOTSUP.
   * @zero_dry_run: used for zeroed == true only, don't update L2 table, just try
   *                with each cluster. By dry run we can find if the zero write
   *                is possible without modifying image data.
   *
   * Returns: error code with 0 for success.
   */
  static int vmdk_pwritev(BlockDriverState *bs, uint64_t offset,
                         uint64_t bytes, QEMUIOVector *qiov,
                         bool zeroed, bool zero_dry_run)
  {
      BDRVVmdkState *s = bs->opaque;
      VmdkExtent *extent = NULL;
      int ret;
      int64_t offset_in_cluster, n_bytes;
      uint64_t cluster_offset;
      uint64_t bytes_done = 0;
      VmdkMetaData m_data;
  
      if (DIV_ROUND_UP(offset, BDRV_SECTOR_SIZE) > bs->total_sectors) {
          error_report("Wrong offset: offset=0x%" PRIx64
                       " total_sectors=0x%" PRIx64,
                       offset, bs->total_sectors);
          return -EIO;
      }
  
      while (bytes > 0) {
          extent = find_extent(s, offset >> BDRV_SECTOR_BITS, extent);
          if (!extent) {
              return -EIO;
          }
          if (extent->sesparse) {
              return -ENOTSUP;
          }
          offset_in_cluster = vmdk_find_offset_in_cluster(extent, offset);
          n_bytes = MIN(bytes, extent->cluster_sectors * BDRV_SECTOR_SIZE
                               - offset_in_cluster);
  
          ret = get_cluster_offset(bs, extent, &m_data, offset,
                                   !(extent->compressed || zeroed),
                                   &cluster_offset, offset_in_cluster,
                                   offset_in_cluster + n_bytes);
          if (extent->compressed) {
              if (ret == VMDK_OK) {
                  /* Refuse write to allocated cluster for streamOptimized */
                  error_report("Could not write to allocated cluster"
                                " for streamOptimized");
                  return -EIO;
              } else if (!zeroed) {
                  /* allocate */
                  ret = get_cluster_offset(bs, extent, &m_data, offset,
                                           true, &cluster_offset, 0, 0);
              }
          }
          if (ret == VMDK_ERROR) {
              return -EINVAL;
          }
          if (zeroed) {
              /* Do zeroed write, buf is ignored */
              if (extent->has_zero_grain &&
                      offset_in_cluster == 0 &&
                      n_bytes >= extent->cluster_sectors * BDRV_SECTOR_SIZE) {
                  n_bytes = extent->cluster_sectors * BDRV_SECTOR_SIZE;
                  if (!zero_dry_run && ret != VMDK_ZEROED) {
                      /* update L2 tables */
                      if (vmdk_L2update(extent, &m_data, VMDK_GTE_ZEROED)
                              != VMDK_OK) {
                          return -EIO;
                      }
                  }
              } else {
                  return -ENOTSUP;
              }
          } else {
              ret = vmdk_write_extent(extent, cluster_offset, offset_in_cluster,
                                      qiov, bytes_done, n_bytes, offset);
              if (ret) {
                  return ret;
              }
              if (m_data.new_allocation) {
                  /* update L2 tables */
                  if (vmdk_L2update(extent, &m_data,
                                    cluster_offset >> BDRV_SECTOR_BITS)
                          != VMDK_OK) {
                      return -EIO;
                  }
              }
          }
          bytes -= n_bytes;
          offset += n_bytes;
          bytes_done += n_bytes;
  
          /* update CID on the first write every time the virtual disk is
           * opened */
          if (!s->cid_updated) {
              ret = vmdk_write_cid(bs, g_random_int());
              if (ret < 0) {
                  return ret;
              }
              s->cid_updated = true;
          }
      }
      return 0;
  }
  
  static int coroutine_fn
  vmdk_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                  QEMUIOVector *qiov, int flags)
  {
      int ret;
      BDRVVmdkState *s = bs->opaque;
      qemu_co_mutex_lock(&s->lock);
      ret = vmdk_pwritev(bs, offset, bytes, qiov, false, false);
      qemu_co_mutex_unlock(&s->lock);
      return ret;
  }
  
  static int coroutine_fn
  vmdk_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
                             uint64_t bytes, QEMUIOVector *qiov)
  {
      if (bytes == 0) {
          /* The caller will write bytes 0 to signal EOF.
           * When receive it, we align EOF to a sector boundary. */
          BDRVVmdkState *s = bs->opaque;
          int i, ret;
          int64_t length;
  
          for (i = 0; i < s->num_extents; i++) {
              length = bdrv_getlength(s->extents[i].file->bs);
              if (length < 0) {
                  return length;
              }
              length = QEMU_ALIGN_UP(length, BDRV_SECTOR_SIZE);
              ret = bdrv_truncate(s->extents[i].file, length, false,
                                  PREALLOC_MODE_OFF, 0, NULL);
              if (ret < 0) {
                  return ret;
              }
          }
          return 0;
      }
      return vmdk_co_pwritev(bs, offset, bytes, qiov, 0);
  }
  
  static int coroutine_fn vmdk_co_pwrite_zeroes(BlockDriverState *bs,
                                                int64_t offset,
                                                int bytes,
                                                BdrvRequestFlags flags)
  {
      int ret;
      BDRVVmdkState *s = bs->opaque;
  
      qemu_co_mutex_lock(&s->lock);
      /* write zeroes could fail if sectors not aligned to cluster, test it with
       * dry_run == true before really updating image */
      ret = vmdk_pwritev(bs, offset, bytes, NULL, true, true);
      if (!ret) {
          ret = vmdk_pwritev(bs, offset, bytes, NULL, true, false);
      }
      qemu_co_mutex_unlock(&s->lock);
      return ret;
  }
  
  static int vmdk_init_extent(BlockBackend *blk,
                              int64_t filesize, bool flat,
                              bool compress, bool zeroed_grain,
                              Error **errp)
  {
      int ret, i;
      VMDK4Header header;
      uint32_t tmp, magic, grains, gd_sectors, gt_size, gt_count;
      uint32_t *gd_buf = NULL;
      int gd_buf_size;
  
      if (flat) {
          ret = blk_truncate(blk, filesize, false, PREALLOC_MODE_OFF, 0, errp);
          goto exit;
      }
      magic = cpu_to_be32(VMDK4_MAGIC);
      memset(&header, 0, sizeof(header));
      if (compress) {
          header.version = 3;
      } else if (zeroed_grain) {
          header.version = 2;
      } else {
          header.version = 1;
      }
      header.flags = VMDK4_FLAG_RGD | VMDK4_FLAG_NL_DETECT
                     | (compress ? VMDK4_FLAG_COMPRESS | VMDK4_FLAG_MARKER : 0)
                     | (zeroed_grain ? VMDK4_FLAG_ZERO_GRAIN : 0);
      header.compressAlgorithm = compress ? VMDK4_COMPRESSION_DEFLATE : 0;
      header.capacity = filesize / BDRV_SECTOR_SIZE;
      header.granularity = 128;
      header.num_gtes_per_gt = BDRV_SECTOR_SIZE;
  
      grains = DIV_ROUND_UP(filesize / BDRV_SECTOR_SIZE, header.granularity);
      gt_size = DIV_ROUND_UP(header.num_gtes_per_gt * sizeof(uint32_t),
                             BDRV_SECTOR_SIZE);
      gt_count = DIV_ROUND_UP(grains, header.num_gtes_per_gt);
      gd_sectors = DIV_ROUND_UP(gt_count * sizeof(uint32_t), BDRV_SECTOR_SIZE);
  
      header.desc_offset = 1;
      header.desc_size = 20;
      header.rgd_offset = header.desc_offset + header.desc_size;
      header.gd_offset = header.rgd_offset + gd_sectors + (gt_size * gt_count);
      header.grain_offset =
          ROUND_UP(header.gd_offset + gd_sectors + (gt_size * gt_count),
                   header.granularity);
      /* swap endianness for all header fields */
      header.version = cpu_to_le32(header.version);
      header.flags = cpu_to_le32(header.flags);
      header.capacity = cpu_to_le64(header.capacity);
      header.granularity = cpu_to_le64(header.granularity);
      header.num_gtes_per_gt = cpu_to_le32(header.num_gtes_per_gt);
      header.desc_offset = cpu_to_le64(header.desc_offset);
      header.desc_size = cpu_to_le64(header.desc_size);
      header.rgd_offset = cpu_to_le64(header.rgd_offset);
      header.gd_offset = cpu_to_le64(header.gd_offset);
      header.grain_offset = cpu_to_le64(header.grain_offset);
      header.compressAlgorithm = cpu_to_le16(header.compressAlgorithm);
  
      header.check_bytes[0] = 0xa;
      header.check_bytes[1] = 0x20;
      header.check_bytes[2] = 0xd;
      header.check_bytes[3] = 0xa;
  
      /* write all the data */
      ret = blk_pwrite(blk, 0, &magic, sizeof(magic), 0);
      if (ret < 0) {
          error_setg(errp, QERR_IO_ERROR);
          goto exit;
      }
      ret = blk_pwrite(blk, sizeof(magic), &header, sizeof(header), 0);
      if (ret < 0) {
          error_setg(errp, QERR_IO_ERROR);
          goto exit;
      }
  
      ret = blk_truncate(blk, le64_to_cpu(header.grain_offset) << 9, false,
                         PREALLOC_MODE_OFF, 0, errp);
      if (ret < 0) {
          goto exit;
      }
  
      /* write grain directory */
      gd_buf_size = gd_sectors * BDRV_SECTOR_SIZE;
      gd_buf = g_malloc0(gd_buf_size);
      for (i = 0, tmp = le64_to_cpu(header.rgd_offset) + gd_sectors;
           i < gt_count; i++, tmp += gt_size) {
          gd_buf[i] = cpu_to_le32(tmp);
      }
      ret = blk_pwrite(blk, le64_to_cpu(header.rgd_offset) * BDRV_SECTOR_SIZE,
                       gd_buf, gd_buf_size, 0);
      if (ret < 0) {
          error_setg(errp, QERR_IO_ERROR);
          goto exit;
      }
  
      /* write backup grain directory */
      for (i = 0, tmp = le64_to_cpu(header.gd_offset) + gd_sectors;
           i < gt_count; i++, tmp += gt_size) {
          gd_buf[i] = cpu_to_le32(tmp);
      }
      ret = blk_pwrite(blk, le64_to_cpu(header.gd_offset) * BDRV_SECTOR_SIZE,
                       gd_buf, gd_buf_size, 0);
      if (ret < 0) {
          error_setg(errp, QERR_IO_ERROR);
      }
  
      ret = 0;
  exit:
      g_free(gd_buf);
      return ret;
  }
  
  static int vmdk_create_extent(const char *filename, int64_t filesize,
                                bool flat, bool compress, bool zeroed_grain,
                                BlockBackend **pbb,
                                QemuOpts *opts, Error **errp)
  {
      int ret;
      BlockBackend *blk = NULL;
  
      ret = bdrv_create_file(filename, opts, errp);
      if (ret < 0) {
          goto exit;
      }
  
      blk = blk_new_open(filename, NULL, NULL,
                         BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
                         errp);
      if (blk == NULL) {
          ret = -EIO;
          goto exit;
      }
  
      blk_set_allow_write_beyond_eof(blk, true);
  
      ret = vmdk_init_extent(blk, filesize, flat, compress, zeroed_grain, errp);
  exit:
      if (blk) {
          if (pbb) {
              *pbb = blk;
          } else {
              blk_unref(blk);
              blk = NULL;
          }
      }
      return ret;
  }
  
  static int filename_decompose(const char *filename, char *path, char *prefix,
                                char *postfix, size_t buf_len, Error **errp)
  {
      const char *p, *q;
  
      if (filename == NULL || !strlen(filename)) {
          error_setg(errp, "No filename provided");
          return VMDK_ERROR;
      }
      p = strrchr(filename, '/');
      if (p == NULL) {
          p = strrchr(filename, '\\');
      }
      if (p == NULL) {
          p = strrchr(filename, ':');
      }
      if (p != NULL) {
          p++;
          if (p - filename >= buf_len) {
              return VMDK_ERROR;
          }
          pstrcpy(path, p - filename + 1, filename);
      } else {
          p = filename;
          path[0] = '\0';
      }
      q = strrchr(p, '.');
      if (q == NULL) {
          pstrcpy(prefix, buf_len, p);
          postfix[0] = '\0';
      } else {
          if (q - p >= buf_len) {
              return VMDK_ERROR;
          }
          pstrcpy(prefix, q - p + 1, p);
          pstrcpy(postfix, buf_len, q);
      }
      return VMDK_OK;
  }
  
  /*
   * idx == 0: get or create the descriptor file (also the image file if in a
   *           non-split format.
   * idx >= 1: get the n-th extent if in a split subformat
   */
  typedef BlockBackend *(*vmdk_create_extent_fn)(int64_t size,
                                                 int idx,
                                                 bool flat,
                                                 bool split,
                                                 bool compress,
                                                 bool zeroed_grain,
                                                 void *opaque,
                                                 Error **errp);
  
  static void vmdk_desc_add_extent(GString *desc,
                                   const char *extent_line_fmt,
                                   int64_t size, const char *filename)
  {
      char *basename = g_path_get_basename(filename);
  
      g_string_append_printf(desc, extent_line_fmt,
                             DIV_ROUND_UP(size, BDRV_SECTOR_SIZE), basename);
      g_free(basename);
  }
  
  static int coroutine_fn vmdk_co_do_create(int64_t size,
                                            BlockdevVmdkSubformat subformat,
                                            BlockdevVmdkAdapterType adapter_type,
                                            const char *backing_file,
                                            const char *hw_version,
                                            bool compat6,
                                            bool zeroed_grain,
                                            vmdk_create_extent_fn extent_fn,
                                            void *opaque,
                                            Error **errp)
  {
      int extent_idx;
      BlockBackend *blk = NULL;
      BlockBackend *extent_blk;
      Error *local_err = NULL;
      char *desc = NULL;
      int ret = 0;
      bool flat, split, compress;
      GString *ext_desc_lines;
      const int64_t split_size = 0x80000000;  /* VMDK has constant split size */
      int64_t extent_size;
      int64_t created_size = 0;
      const char *extent_line_fmt;
      char *parent_desc_line = g_malloc0(BUF_SIZE);
      uint32_t parent_cid = 0xffffffff;
      uint32_t number_heads = 16;
      uint32_t desc_offset = 0, desc_len;
      const char desc_template[] =
          "# Disk DescriptorFile\n"
          "version=1\n"
          "CID=%" PRIx32 "\n"
          "parentCID=%" PRIx32 "\n"
          "createType=\"%s\"\n"
          "%s"
          "\n"
          "# Extent description\n"
          "%s"
          "\n"
          "# The Disk Data Base\n"
          "#DDB\n"
          "\n"
          "ddb.virtualHWVersion = \"%s\"\n"
          "ddb.geometry.cylinders = \"%" PRId64 "\"\n"
          "ddb.geometry.heads = \"%" PRIu32 "\"\n"
          "ddb.geometry.sectors = \"63\"\n"
          "ddb.adapterType = \"%s\"\n";
  
      ext_desc_lines = g_string_new(NULL);
  
      /* Read out options */
      if (compat6) {
          if (hw_version) {
              error_setg(errp,
                         "compat6 cannot be enabled with hwversion set");
              ret = -EINVAL;
              goto exit;
          }
          hw_version = "6";
      }
      if (!hw_version) {
          hw_version = "4";
      }
  
      if (adapter_type != BLOCKDEV_VMDK_ADAPTER_TYPE_IDE) {
          /* that's the number of heads with which vmware operates when
             creating, exporting, etc. vmdk files with a non-ide adapter type */
          number_heads = 255;
      }
      split = (subformat == BLOCKDEV_VMDK_SUBFORMAT_TWOGBMAXEXTENTFLAT) ||
              (subformat == BLOCKDEV_VMDK_SUBFORMAT_TWOGBMAXEXTENTSPARSE);
      flat = (subformat == BLOCKDEV_VMDK_SUBFORMAT_MONOLITHICFLAT) ||
             (subformat == BLOCKDEV_VMDK_SUBFORMAT_TWOGBMAXEXTENTFLAT);
      compress = subformat == BLOCKDEV_VMDK_SUBFORMAT_STREAMOPTIMIZED;
  
      if (flat) {
          extent_line_fmt = "RW %" PRId64 " FLAT \"%s\" 0\n";
      } else {
          extent_line_fmt = "RW %" PRId64 " SPARSE \"%s\"\n";
      }
      if (flat && backing_file) {
          error_setg(errp, "Flat image can't have backing file");
          ret = -ENOTSUP;
          goto exit;
      }
      if (flat && zeroed_grain) {
          error_setg(errp, "Flat image can't enable zeroed grain");
          ret = -ENOTSUP;
          goto exit;
      }
  
      /* Create extents */
      if (split) {
          extent_size = split_size;
      } else {
          extent_size = size;
      }
      if (!split && !flat) {
          created_size = extent_size;
      } else {
          created_size = 0;
      }
      /* Get the descriptor file BDS */
      blk = extent_fn(created_size, 0, flat, split, compress, zeroed_grain,
                      opaque, errp);
      if (!blk) {
          ret = -EIO;
          goto exit;
      }
      if (!split && !flat) {
          vmdk_desc_add_extent(ext_desc_lines, extent_line_fmt, created_size,
                               blk_bs(blk)->filename);
      }
  
      if (backing_file) {
          BlockBackend *backing;
          char *full_backing =
              bdrv_get_full_backing_filename_from_filename(blk_bs(blk)->filename,
                                                           backing_file,
                                                           &local_err);
          if (local_err) {
              error_propagate(errp, local_err);
              ret = -ENOENT;
              goto exit;
          }
          assert(full_backing);
  
          backing = blk_new_open(full_backing, NULL, NULL,
                                 BDRV_O_NO_BACKING, errp);
          g_free(full_backing);
          if (backing == NULL) {
              ret = -EIO;
              goto exit;
          }
          if (strcmp(blk_bs(backing)->drv->format_name, "vmdk")) {
              error_setg(errp, "Invalid backing file format: %s. Must be vmdk",
                         blk_bs(backing)->drv->format_name);
              blk_unref(backing);
              ret = -EINVAL;
              goto exit;
          }
          ret = vmdk_read_cid(blk_bs(backing), 0, &parent_cid);
          blk_unref(backing);
          if (ret) {
              error_setg(errp, "Failed to read parent CID");
              goto exit;
          }
          snprintf(parent_desc_line, BUF_SIZE,
                  "parentFileNameHint=\"%s\"", backing_file);
      }
      extent_idx = 1;
      while (created_size < size) {
          int64_t cur_size = MIN(size - created_size, extent_size);
          extent_blk = extent_fn(cur_size, extent_idx, flat, split, compress,
                                 zeroed_grain, opaque, errp);
          if (!extent_blk) {
              ret = -EINVAL;
              goto exit;
          }
          vmdk_desc_add_extent(ext_desc_lines, extent_line_fmt, cur_size,
                               blk_bs(extent_blk)->filename);
          created_size += cur_size;
          extent_idx++;
          blk_unref(extent_blk);
      }
  
      /* Check whether we got excess extents */
      extent_blk = extent_fn(-1, extent_idx, flat, split, compress, zeroed_grain,
                             opaque, NULL);
      if (extent_blk) {
          blk_unref(extent_blk);
          error_setg(errp, "List of extents contains unused extents");
          ret = -EINVAL;
          goto exit;
      }
  
      /* generate descriptor file */
      desc = g_strdup_printf(desc_template,
                             g_random_int(),
                             parent_cid,
                             BlockdevVmdkSubformat_str(subformat),
                             parent_desc_line,
                             ext_desc_lines->str,
                             hw_version,
                             size /
                                 (int64_t)(63 * number_heads * BDRV_SECTOR_SIZE),
                             number_heads,
                             BlockdevVmdkAdapterType_str(adapter_type));
      desc_len = strlen(desc);
      /* the descriptor offset = 0x200 */
      if (!split && !flat) {
          desc_offset = 0x200;
      }
  
      ret = blk_pwrite(blk, desc_offset, desc, desc_len, 0);
      if (ret < 0) {
          error_setg_errno(errp, -ret, "Could not write description");
          goto exit;
      }
      /* bdrv_pwrite write padding zeros to align to sector, we don't need that
       * for description file */
      if (desc_offset == 0) {
          ret = blk_truncate(blk, desc_len, false, PREALLOC_MODE_OFF, 0, errp);
          if (ret < 0) {
              goto exit;
          }
      }
      ret = 0;
  exit:
      if (blk) {
          blk_unref(blk);
      }
      g_free(desc);
      g_free(parent_desc_line);
      g_string_free(ext_desc_lines, true);
      return ret;
  }
  
  typedef struct {
      char *path;
      char *prefix;
      char *postfix;
      QemuOpts *opts;
  } VMDKCreateOptsData;
  
  static BlockBackend *vmdk_co_create_opts_cb(int64_t size, int idx,
                                              bool flat, bool split, bool compress,
                                              bool zeroed_grain, void *opaque,
                                              Error **errp)
  {
      BlockBackend *blk = NULL;
      BlockDriverState *bs = NULL;
      VMDKCreateOptsData *data = opaque;
      char *ext_filename = NULL;
      char *rel_filename = NULL;
  
      /* We're done, don't create excess extents. */
      if (size == -1) {
          assert(errp == NULL);
          return NULL;
      }
  
      if (idx == 0) {
          rel_filename = g_strdup_printf("%s%s", data->prefix, data->postfix);
      } else if (split) {
          rel_filename = g_strdup_printf("%s-%c%03d%s",
                                         data->prefix,
                                         flat ? 'f' : 's', idx, data->postfix);
      } else {
          assert(idx == 1);
          rel_filename = g_strdup_printf("%s-flat%s", data->prefix, data->postfix);
      }
  
      ext_filename = g_strdup_printf("%s%s", data->path, rel_filename);
      g_free(rel_filename);
  
      if (vmdk_create_extent(ext_filename, size,
                             flat, compress, zeroed_grain, &blk, data->opts,
                             errp)) {
          goto exit;
      }
      bdrv_unref(bs);
  exit:
      g_free(ext_filename);
      return blk;
  }
  
  static int coroutine_fn vmdk_co_create_opts(BlockDriver *drv,
                                              const char *filename,
                                              QemuOpts *opts,
                                              Error **errp)
  {
      Error *local_err = NULL;
      char *desc = NULL;
      int64_t total_size = 0;
      char *adapter_type = NULL;
      BlockdevVmdkAdapterType adapter_type_enum;
      char *backing_file = NULL;
      char *hw_version = NULL;
      char *fmt = NULL;
      BlockdevVmdkSubformat subformat;
      int ret = 0;
      char *path = g_malloc0(PATH_MAX);
      char *prefix = g_malloc0(PATH_MAX);
      char *postfix = g_malloc0(PATH_MAX);
      char *desc_line = g_malloc0(BUF_SIZE);
      char *ext_filename = g_malloc0(PATH_MAX);
      char *desc_filename = g_malloc0(PATH_MAX);
      char *parent_desc_line = g_malloc0(BUF_SIZE);
      bool zeroed_grain;
      bool compat6;
      VMDKCreateOptsData data;
      char *backing_fmt = NULL;
  
      backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
      if (backing_fmt && strcmp(backing_fmt, "vmdk") != 0) {
          error_setg(errp, "backing_file must be a vmdk image");
          ret = -EINVAL;
          goto exit;
      }
  
      if (filename_decompose(filename, path, prefix, postfix, PATH_MAX, errp)) {
          ret = -EINVAL;
          goto exit;
      }
      /* Read out options */
      total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
                            BDRV_SECTOR_SIZE);
      adapter_type = qemu_opt_get_del(opts, BLOCK_OPT_ADAPTER_TYPE);
      backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
      hw_version = qemu_opt_get_del(opts, BLOCK_OPT_HWVERSION);
      compat6 = qemu_opt_get_bool_del(opts, BLOCK_OPT_COMPAT6, false);
      if (strcmp(hw_version, "undefined") == 0) {
          g_free(hw_version);
          hw_version = NULL;
      }
      fmt = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);
      zeroed_grain = qemu_opt_get_bool_del(opts, BLOCK_OPT_ZEROED_GRAIN, false);
  
      if (adapter_type) {
          adapter_type_enum = qapi_enum_parse(&BlockdevVmdkAdapterType_lookup,
                                              adapter_type,
                                              BLOCKDEV_VMDK_ADAPTER_TYPE_IDE,
                                              &local_err);
          if (local_err) {
              error_propagate(errp, local_err);
              ret = -EINVAL;
              goto exit;
          }
      } else {
          adapter_type_enum = BLOCKDEV_VMDK_ADAPTER_TYPE_IDE;
      }
  
      if (!fmt) {
          /* Default format to monolithicSparse */
          subformat = BLOCKDEV_VMDK_SUBFORMAT_MONOLITHICSPARSE;
      } else {
          subformat = qapi_enum_parse(&BlockdevVmdkSubformat_lookup,
                                      fmt,
                                      BLOCKDEV_VMDK_SUBFORMAT_MONOLITHICSPARSE,
                                      &local_err);
          if (local_err) {
              error_propagate(errp, local_err);
              ret = -EINVAL;
              goto exit;
          }
      }
      data = (VMDKCreateOptsData){
          .prefix = prefix,
          .postfix = postfix,
          .path = path,
          .opts = opts,
      };
      ret = vmdk_co_do_create(total_size, subformat, adapter_type_enum,
                              backing_file, hw_version, compat6, zeroed_grain,
                              vmdk_co_create_opts_cb, &data, errp);
  
  exit:
      g_free(backing_fmt);
      g_free(adapter_type);
      g_free(backing_file);
      g_free(hw_version);
      g_free(fmt);
      g_free(desc);
      g_free(path);
      g_free(prefix);
      g_free(postfix);
      g_free(desc_line);
      g_free(ext_filename);
      g_free(desc_filename);
      g_free(parent_desc_line);
      return ret;
  }
  
  static BlockBackend *vmdk_co_create_cb(int64_t size, int idx,
                                         bool flat, bool split, bool compress,
                                         bool zeroed_grain, void *opaque,
                                         Error **errp)
  {
      int ret;
      BlockDriverState *bs;
      BlockBackend *blk;
      BlockdevCreateOptionsVmdk *opts = opaque;
  
      if (idx == 0) {
          bs = bdrv_open_blockdev_ref(opts->file, errp);
      } else {
          int i;
          BlockdevRefList *list = opts->extents;
          for (i = 1; i < idx; i++) {
              if (!list || !list->next) {
                  error_setg(errp, "Extent [%d] not specified", i);
                  return NULL;
              }
              list = list->next;
          }
          if (!list) {
              error_setg(errp, "Extent [%d] not specified", idx - 1);
              return NULL;
          }
          bs = bdrv_open_blockdev_ref(list->value, errp);
      }
      if (!bs) {
          return NULL;
      }
      blk = blk_new_with_bs(bs,
                            BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_RESIZE,
                            BLK_PERM_ALL, errp);
      if (!blk) {
          return NULL;
      }
      blk_set_allow_write_beyond_eof(blk, true);
      bdrv_unref(bs);
  
      if (size != -1) {
          ret = vmdk_init_extent(blk, size, flat, compress, zeroed_grain, errp);
          if (ret) {
              blk_unref(blk);
              blk = NULL;
          }
      }
      return blk;
  }
  
  static int coroutine_fn vmdk_co_create(BlockdevCreateOptions *create_options,
                                         Error **errp)
  {
      int ret;
      BlockdevCreateOptionsVmdk *opts;
  
      opts = &create_options->u.vmdk;
  
      /* Validate options */
      if (!QEMU_IS_ALIGNED(opts->size, BDRV_SECTOR_SIZE)) {
          error_setg(errp, "Image size must be a multiple of 512 bytes");
          ret = -EINVAL;
          goto out;
      }
  
      ret = vmdk_co_do_create(opts->size,
                              opts->subformat,
                              opts->adapter_type,
                              opts->backing_file,
                              opts->hwversion,
                              false,
                              opts->zeroed_grain,
                              vmdk_co_create_cb,
                              opts, errp);
      return ret;
  
  out:
      return ret;
  }
  
  static void vmdk_close(BlockDriverState *bs)
  {
      BDRVVmdkState *s = bs->opaque;
  
      vmdk_free_extents(bs);
      g_free(s->create_type);
  
      migrate_del_blocker(s->migration_blocker);
      error_free(s->migration_blocker);
  }
  
  static int64_t vmdk_get_allocated_file_size(BlockDriverState *bs)
  {
      int i;
      int64_t ret = 0;
      int64_t r;
      BDRVVmdkState *s = bs->opaque;
  
      ret = bdrv_get_allocated_file_size(bs->file->bs);
      if (ret < 0) {
          return ret;
      }
      for (i = 0; i < s->num_extents; i++) {
          if (s->extents[i].file == bs->file) {
              continue;
          }
          r = bdrv_get_allocated_file_size(s->extents[i].file->bs);
          if (r < 0) {
              return r;
          }
          ret += r;
      }
      return ret;
  }
  
  static int vmdk_has_zero_init(BlockDriverState *bs)
  {
      int i;
      BDRVVmdkState *s = bs->opaque;
  
      /* If has a flat extent and its underlying storage doesn't have zero init,
       * return 0. */
      for (i = 0; i < s->num_extents; i++) {
          if (s->extents[i].flat) {
              if (!bdrv_has_zero_init(s->extents[i].file->bs)) {
                  return 0;
              }
          }
      }
      return 1;
  }
  
  static ImageInfo *vmdk_get_extent_info(VmdkExtent *extent)
  {
      ImageInfo *info = g_new0(ImageInfo, 1);
  
      bdrv_refresh_filename(extent->file->bs);
      *info = (ImageInfo){
          .filename         = g_strdup(extent->file->bs->filename),
          .format           = g_strdup(extent->type),
          .virtual_size     = extent->sectors * BDRV_SECTOR_SIZE,
          .compressed       = extent->compressed,
          .has_compressed   = extent->compressed,
          .cluster_size     = extent->cluster_sectors * BDRV_SECTOR_SIZE,
          .has_cluster_size = !extent->flat,
      };
  
      return info;
  }
  
  static int coroutine_fn vmdk_co_check(BlockDriverState *bs,
                                        BdrvCheckResult *result,
                                        BdrvCheckMode fix)
  {
      BDRVVmdkState *s = bs->opaque;
      VmdkExtent *extent = NULL;
      int64_t sector_num = 0;
      int64_t total_sectors = bdrv_nb_sectors(bs);
      int ret;
      uint64_t cluster_offset;
  
      if (fix) {
          return -ENOTSUP;
      }
  
      for (;;) {
          if (sector_num >= total_sectors) {
              return 0;
          }
          extent = find_extent(s, sector_num, extent);
          if (!extent) {
              fprintf(stderr,
                      "ERROR: could not find extent for sector %" PRId64 "\n",
                      sector_num);
              ret = -EINVAL;
              break;
          }
          ret = get_cluster_offset(bs, extent, NULL,
                                   sector_num << BDRV_SECTOR_BITS,
                                   false, &cluster_offset, 0, 0);
          if (ret == VMDK_ERROR) {
              fprintf(stderr,
                      "ERROR: could not get cluster_offset for sector %"
                      PRId64 "\n", sector_num);
              break;
          }
          if (ret == VMDK_OK) {
              int64_t extent_len = bdrv_getlength(extent->file->bs);
              if (extent_len < 0) {
                  fprintf(stderr,
                          "ERROR: could not get extent file length for sector %"
                          PRId64 "\n", sector_num);
                  ret = extent_len;
                  break;
              }
              if (cluster_offset >= extent_len) {
                  fprintf(stderr,
                          "ERROR: cluster offset for sector %"
                          PRId64 " points after EOF\n", sector_num);
                  ret = -EINVAL;
                  break;
              }
          }
          sector_num += extent->cluster_sectors;
      }
  
      result->corruptions++;
      return ret;
  }
  
  static ImageInfoSpecific *vmdk_get_specific_info(BlockDriverState *bs,
                                                   Error **errp)
  {
      int i;
      BDRVVmdkState *s = bs->opaque;
      ImageInfoSpecific *spec_info = g_new0(ImageInfoSpecific, 1);
      ImageInfoList **tail;
  
      *spec_info = (ImageInfoSpecific){
          .type = IMAGE_INFO_SPECIFIC_KIND_VMDK,
          .u = {
              .vmdk.data = g_new0(ImageInfoSpecificVmdk, 1),
          },
      };
  
      *spec_info->u.vmdk.data = (ImageInfoSpecificVmdk) {
          .create_type = g_strdup(s->create_type),
          .cid = s->cid,
          .parent_cid = s->parent_cid,
      };
  
      tail = &spec_info->u.vmdk.data->extents;
      for (i = 0; i < s->num_extents; i++) {
          QAPI_LIST_APPEND(tail, vmdk_get_extent_info(&s->extents[i]));
      }
  
      return spec_info;
  }
  
  static bool vmdk_extents_type_eq(const VmdkExtent *a, const VmdkExtent *b)
  {
      return a->flat == b->flat &&
             a->compressed == b->compressed &&
             (a->flat || a->cluster_sectors == b->cluster_sectors);
  }
  
  static int vmdk_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
  {
      int i;
      BDRVVmdkState *s = bs->opaque;
      assert(s->num_extents);
  
      /* See if we have multiple extents but they have different cases */
      for (i = 1; i < s->num_extents; i++) {
          if (!vmdk_extents_type_eq(&s->extents[0], &s->extents[i])) {
              return -ENOTSUP;
          }
      }
      bdi->needs_compressed_writes = s->extents[0].compressed;
      if (!s->extents[0].flat) {
          bdi->cluster_size = s->extents[0].cluster_sectors << BDRV_SECTOR_BITS;
      }
      return 0;
  }
  
  static void vmdk_gather_child_options(BlockDriverState *bs, QDict *target,
                                        bool backing_overridden)
  {
      /* No children but file and backing can be explicitly specified (TODO) */
      qdict_put(target, "file",
                qobject_ref(bs->file->bs->full_open_options));
  
      if (backing_overridden) {
          if (bs->backing) {
              qdict_put(target, "backing",
                        qobject_ref(bs->backing->bs->full_open_options));
          } else {
              qdict_put_null(target, "backing");
          }
      }
  }
  
  static QemuOptsList vmdk_create_opts = {
      .name = "vmdk-create-opts",
      .head = QTAILQ_HEAD_INITIALIZER(vmdk_create_opts.head),
      .desc = {
          {
              .name = BLOCK_OPT_SIZE,
              .type = QEMU_OPT_SIZE,
              .help = "Virtual disk size"
          },
          {
              .name = BLOCK_OPT_ADAPTER_TYPE,
              .type = QEMU_OPT_STRING,
              .help = "Virtual adapter type, can be one of "
                      "ide (default), lsilogic, buslogic or legacyESX"
          },
          {
              .name = BLOCK_OPT_BACKING_FILE,
              .type = QEMU_OPT_STRING,
              .help = "File name of a base image"
          },
          {
              .name = BLOCK_OPT_BACKING_FMT,
              .type = QEMU_OPT_STRING,
              .help = "Must be 'vmdk' if present",
          },
          {
              .name = BLOCK_OPT_COMPAT6,
              .type = QEMU_OPT_BOOL,
              .help = "VMDK version 6 image",
              .def_value_str = "off"
          },
          {
              .name = BLOCK_OPT_HWVERSION,
              .type = QEMU_OPT_STRING,
              .help = "VMDK hardware version",
              .def_value_str = "undefined"
          },
          {
              .name = BLOCK_OPT_SUBFMT,
              .type = QEMU_OPT_STRING,
              .help =
                  "VMDK flat extent format, can be one of "
                  "{monolithicSparse (default) | monolithicFlat | twoGbMaxExtentSparse | twoGbMaxExtentFlat | streamOptimized} "
          },
          {
              .name = BLOCK_OPT_ZEROED_GRAIN,
              .type = QEMU_OPT_BOOL,
              .help = "Enable efficient zero writes "
                      "using the zeroed-grain GTE feature"
          },
          { /* end of list */ }
      }
  };
  
  static BlockDriver bdrv_vmdk = {
      .format_name                  = "vmdk",
      .instance_size                = sizeof(BDRVVmdkState),
      .bdrv_probe                   = vmdk_probe,
      .bdrv_open                    = vmdk_open,
      .bdrv_co_check                = vmdk_co_check,
      .bdrv_reopen_prepare          = vmdk_reopen_prepare,
      .bdrv_child_perm              = bdrv_default_perms,
      .bdrv_co_preadv               = vmdk_co_preadv,
      .bdrv_co_pwritev              = vmdk_co_pwritev,
      .bdrv_co_pwritev_compressed   = vmdk_co_pwritev_compressed,
      .bdrv_co_pwrite_zeroes        = vmdk_co_pwrite_zeroes,
      .bdrv_close                   = vmdk_close,
      .bdrv_co_create_opts          = vmdk_co_create_opts,
      .bdrv_co_create               = vmdk_co_create,
      .bdrv_co_block_status         = vmdk_co_block_status,
      .bdrv_get_allocated_file_size = vmdk_get_allocated_file_size,
      .bdrv_has_zero_init           = vmdk_has_zero_init,
      .bdrv_get_specific_info       = vmdk_get_specific_info,
      .bdrv_refresh_limits          = vmdk_refresh_limits,
      .bdrv_get_info                = vmdk_get_info,
      .bdrv_gather_child_options    = vmdk_gather_child_options,
  
      .is_format                    = true,
      .supports_backing             = true,
      .create_opts                  = &vmdk_create_opts,
  };
  
  static void bdrv_vmdk_init(void)
  {
      bdrv_register(&bdrv_vmdk);
  }
  
  block_init(bdrv_vmdk_init);
  