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qemu/block-vmdk.c
ths 630530a652 Fix a race condition and non-leaf imagesgrowing in VMDK chains, by Igor 
Lvovsky.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2987 c046a42c-6fe2-441c-8c8c-71466251a162
2007-06-18 15:01:30 +00:00

840 lines
25 KiB
C
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/*
* 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 "vl.h"
#include "block_int.h"
#define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
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;
} VMDK3Header;
typedef struct {
uint32_t version;
uint32_t flags;
int64_t capacity;
int64_t granularity;
int64_t desc_offset;
int64_t desc_size;
int32_t num_gtes_per_gte;
int64_t rgd_offset;
int64_t gd_offset;
int64_t grain_offset;
char filler[1];
char check_bytes[4];
} __attribute__((packed)) VMDK4Header;
#define L2_CACHE_SIZE 16
typedef struct BDRVVmdkState {
BlockDriverState *hd;
int64_t l1_table_offset;
int64_t l1_backup_table_offset;
uint32_t *l1_table;
uint32_t *l1_backup_table;
unsigned int l1_size;
uint32_t l1_entry_sectors;
unsigned int l2_size;
uint32_t *l2_cache;
uint32_t l2_cache_offsets[L2_CACHE_SIZE];
uint32_t l2_cache_counts[L2_CACHE_SIZE];
unsigned int cluster_sectors;
uint32_t parent_cid;
int is_parent;
} BDRVVmdkState;
typedef struct VmdkMetaData {
uint32_t offset;
unsigned int l1_index;
unsigned int l2_index;
unsigned int l2_offset;
int valid;
} VmdkMetaData;
typedef struct ActiveBDRVState{
BlockDriverState *hd; // active image handler
uint64_t cluster_offset; // current write offset
}ActiveBDRVState;
static ActiveBDRVState activeBDRV;
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
return 0;
}
#define CHECK_CID 1
#define SECTOR_SIZE 512
#define DESC_SIZE 20*SECTOR_SIZE // 20 sectors of 512 bytes each
#define HEADER_SIZE 512 // first sector of 512 bytes
static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
{
BDRVVmdkState *s = bs->opaque;
char desc[DESC_SIZE];
uint32_t cid;
char *p_name, *cid_str;
size_t cid_str_size;
/* the descriptor offset = 0x200 */
if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return 0;
if (parent) {
cid_str = "parentCID";
cid_str_size = sizeof("parentCID");
} else {
cid_str = "CID";
cid_str_size = sizeof("CID");
}
if ((p_name = strstr(desc,cid_str)) != 0) {
p_name += cid_str_size;
sscanf(p_name,"%x",&cid);
}
return cid;
}
static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
{
BDRVVmdkState *s = bs->opaque;
char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
char *p_name, *tmp_str;
/* the descriptor offset = 0x200 */
if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
tmp_str = strstr(desc,"parentCID");
strcpy(tmp_desc, tmp_str);
if ((p_name = strstr(desc,"CID")) != 0) {
p_name += sizeof("CID");
sprintf(p_name,"%x\n",cid);
strcat(desc,tmp_desc);
}
if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
return 0;
}
static int vmdk_is_cid_valid(BlockDriverState *bs)
{
#ifdef CHECK_CID
BDRVVmdkState *s = bs->opaque;
BlockDriverState *p_bs = s->hd->backing_hd;
uint32_t cur_pcid;
if (p_bs) {
cur_pcid = vmdk_read_cid(p_bs,0);
if (s->parent_cid != cur_pcid)
// CID not valid
return 0;
}
#endif
// CID valid
return 1;
}
static int vmdk_snapshot_create(const char *filename, const char *backing_file)
{
int snp_fd, p_fd;
uint32_t p_cid;
char *p_name, *gd_buf, *rgd_buf;
const char *real_filename, *temp_str;
VMDK4Header header;
uint32_t gde_entries, gd_size;
int64_t gd_offset, rgd_offset, capacity, gt_size;
char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];
char *desc_template =
"# Disk DescriptorFile\n"
"version=1\n"
"CID=%x\n"
"parentCID=%x\n"
"createType=\"monolithicSparse\"\n"
"parentFileNameHint=\"%s\"\n"
"\n"
"# Extent description\n"
"RW %lu SPARSE \"%s\"\n"
"\n"
"# The Disk Data Base \n"
"#DDB\n"
"\n";
snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);
if (snp_fd < 0)
return -1;
p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
if (p_fd < 0) {
close(snp_fd);
return -1;
}
/* read the header */
if (lseek(p_fd, 0x0, SEEK_SET) == -1)
goto fail;
if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE)
goto fail;
/* write the header */
if (lseek(snp_fd, 0x0, SEEK_SET) == -1)
goto fail;
if (write(snp_fd, hdr, HEADER_SIZE) == -1)
goto fail;
memset(&header, 0, sizeof(header));
memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
ftruncate(snp_fd, header.grain_offset << 9);
/* the descriptor offset = 0x200 */
if (lseek(p_fd, 0x200, SEEK_SET) == -1)
goto fail;
if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE)
goto fail;
if ((p_name = strstr(p_desc,"CID")) != 0) {
p_name += sizeof("CID");
sscanf(p_name,"%x",&p_cid);
}
real_filename = filename;
if ((temp_str = strrchr(real_filename, '\\')) != NULL)
real_filename = temp_str + 1;
if ((temp_str = strrchr(real_filename, '/')) != NULL)
real_filename = temp_str + 1;
if ((temp_str = strrchr(real_filename, ':')) != NULL)
real_filename = temp_str + 1;
sprintf(s_desc, desc_template, p_cid, p_cid, backing_file
, (uint32_t)header.capacity, real_filename);
/* write the descriptor */
if (lseek(snp_fd, 0x200, SEEK_SET) == -1)
goto fail;
if (write(snp_fd, s_desc, strlen(s_desc)) == -1)
goto fail;
gd_offset = header.gd_offset * SECTOR_SIZE; // offset of GD table
rgd_offset = header.rgd_offset * SECTOR_SIZE; // offset of RGD table
capacity = header.capacity * SECTOR_SIZE; // Extent size
/*
* Each GDE span 32M disk, means:
* 512 GTE per GT, each GTE points to grain
*/
gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;
if (!gt_size)
goto fail;
gde_entries = (uint32_t)(capacity / gt_size); // number of gde/rgde
gd_size = gde_entries * sizeof(uint32_t);
/* write RGD */
rgd_buf = qemu_malloc(gd_size);
if (!rgd_buf)
goto fail;
if (lseek(p_fd, rgd_offset, SEEK_SET) == -1)
goto fail_rgd;
if (read(p_fd, rgd_buf, gd_size) != gd_size)
goto fail_rgd;
if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1)
goto fail_rgd;
if (write(snp_fd, rgd_buf, gd_size) == -1)
goto fail_rgd;
qemu_free(rgd_buf);
/* write GD */
gd_buf = qemu_malloc(gd_size);
if (!gd_buf)
goto fail_rgd;
if (lseek(p_fd, gd_offset, SEEK_SET) == -1)
goto fail_gd;
if (read(p_fd, gd_buf, gd_size) != gd_size)
goto fail_gd;
if (lseek(snp_fd, gd_offset, SEEK_SET) == -1)
goto fail_gd;
if (write(snp_fd, gd_buf, gd_size) == -1)
goto fail_gd;
qemu_free(gd_buf);
close(p_fd);
close(snp_fd);
return 0;
fail_gd:
qemu_free(gd_buf);
fail_rgd:
qemu_free(rgd_buf);
fail:
close(p_fd);
close(snp_fd);
return -1;
}
static void vmdk_parent_close(BlockDriverState *bs)
{
if (bs->backing_hd)
bdrv_close(bs->backing_hd);
}
int parent_open = 0;
static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
{
BDRVVmdkState *s = bs->opaque;
char *p_name;
char desc[DESC_SIZE];
char parent_img_name[1024];
/* the descriptor offset = 0x200 */
if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
if ((p_name = strstr(desc,"parentFileNameHint")) != 0) {
char *end_name;
struct stat file_buf;
p_name += sizeof("parentFileNameHint") + 1;
if ((end_name = strchr(p_name,'\"')) == 0)
return -1;
strncpy(s->hd->backing_file, p_name, end_name - p_name);
if (stat(s->hd->backing_file, &file_buf) != 0) {
path_combine(parent_img_name, sizeof(parent_img_name),
filename, s->hd->backing_file);
} else {
strcpy(parent_img_name, s->hd->backing_file);
}
s->hd->backing_hd = bdrv_new("");
if (!s->hd->backing_hd) {
failure:
bdrv_close(s->hd);
return -1;
}
parent_open = 1;
if (bdrv_open(s->hd->backing_hd, parent_img_name, BDRV_O_RDONLY) < 0)
goto failure;
parent_open = 0;
}
return 0;
}
static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVVmdkState *s = bs->opaque;
uint32_t magic;
int l1_size, i, ret;
if (parent_open)
// Parent must be opened as RO.
flags = BDRV_O_RDONLY;
fprintf(stderr, "(VMDK) image open: flags=0x%x filename=%s\n", flags, bs->filename);
ret = bdrv_file_open(&s->hd, filename, flags);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
goto fail;
magic = be32_to_cpu(magic);
if (magic == VMDK3_MAGIC) {
VMDK3Header header;
if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
goto fail;
s->cluster_sectors = le32_to_cpu(header.granularity);
s->l2_size = 1 << 9;
s->l1_size = 1 << 6;
bs->total_sectors = le32_to_cpu(header.disk_sectors);
s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
s->l1_backup_table_offset = 0;
s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
} else if (magic == VMDK4_MAGIC) {
VMDK4Header header;
if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
goto fail;
bs->total_sectors = le64_to_cpu(header.capacity);
s->cluster_sectors = le64_to_cpu(header.granularity);
s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
if (s->l1_entry_sectors <= 0)
goto fail;
s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
/ s->l1_entry_sectors;
s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
if (parent_open)
s->is_parent = 1;
else
s->is_parent = 0;
// try to open parent images, if exist
if (vmdk_parent_open(bs, filename) != 0)
goto fail;
// write the CID once after the image creation
s->parent_cid = vmdk_read_cid(bs,1);
} else {
goto fail;
}
/* read the L1 table */
l1_size = s->l1_size * sizeof(uint32_t);
s->l1_table = qemu_malloc(l1_size);
if (!s->l1_table)
goto fail;
if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
goto fail;
for(i = 0; i < s->l1_size; i++) {
le32_to_cpus(&s->l1_table[i]);
}
if (s->l1_backup_table_offset) {
s->l1_backup_table = qemu_malloc(l1_size);
if (!s->l1_backup_table)
goto fail;
if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
goto fail;
for(i = 0; i < s->l1_size; i++) {
le32_to_cpus(&s->l1_backup_table[i]);
}
}
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
if (!s->l2_cache)
goto fail;
return 0;
fail:
qemu_free(s->l1_backup_table);
qemu_free(s->l1_table);
qemu_free(s->l2_cache);
bdrv_delete(s->hd);
return -1;
}
static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
uint64_t offset, int allocate);
static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
uint64_t offset, int allocate)
{
uint64_t parent_cluster_offset;
BDRVVmdkState *s = bs->opaque;
uint8_t whole_grain[s->cluster_sectors*512]; // 128 sectors * 512 bytes each = grain size 64KB
// we will be here if it's first write on non-exist grain(cluster).
// try to read from parent image, if exist
if (s->hd->backing_hd) {
BDRVVmdkState *ps = s->hd->backing_hd->opaque;
if (!vmdk_is_cid_valid(bs))
return -1;
parent_cluster_offset = get_cluster_offset(s->hd->backing_hd, NULL, offset, allocate);
if (parent_cluster_offset) {
BDRVVmdkState *act_s = activeBDRV.hd->opaque;
if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) != ps->cluster_sectors*512)
return -1;
//Write grain only into the active image
if (bdrv_pwrite(act_s->hd, activeBDRV.cluster_offset << 9, whole_grain, sizeof(whole_grain)) != sizeof(whole_grain))
return -1;
}
}
return 0;
}
static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)
{
BDRVVmdkState *s = bs->opaque;
/* update L2 table */
if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
&(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
return -1;
/* update backup L2 table */
if (s->l1_backup_table_offset != 0) {
m_data->l2_offset = s->l1_backup_table[m_data->l1_index];
if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
&(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
return -1;
}
return 0;
}
static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
uint64_t offset, int allocate)
{
BDRVVmdkState *s = bs->opaque;
unsigned int l1_index, l2_offset, l2_index;
int min_index, i, j;
uint32_t min_count, *l2_table, tmp = 0;
uint64_t cluster_offset;
int status;
if (m_data)
m_data->valid = 0;
l1_index = (offset >> 9) / s->l1_entry_sectors;
if (l1_index >= s->l1_size)
return 0;
l2_offset = s->l1_table[l1_index];
if (!l2_offset)
return 0;
for(i = 0; i < L2_CACHE_SIZE; i++) {
if (l2_offset == s->l2_cache_offsets[i]) {
/* increment the hit count */
if (++s->l2_cache_counts[i] == 0xffffffff) {
for(j = 0; j < L2_CACHE_SIZE; j++) {
s->l2_cache_counts[j] >>= 1;
}
}
l2_table = s->l2_cache + (i * s->l2_size);
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 (s->l2_cache_counts[i] < min_count) {
min_count = s->l2_cache_counts[i];
min_index = i;
}
}
l2_table = s->l2_cache + (min_index * s->l2_size);
if (bdrv_pread(s->hd, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
s->l2_size * sizeof(uint32_t))
return 0;
s->l2_cache_offsets[min_index] = l2_offset;
s->l2_cache_counts[min_index] = 1;
found:
l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
cluster_offset = le32_to_cpu(l2_table[l2_index]);
if (!cluster_offset) {
struct stat file_buf;
if (!allocate)
return 0;
// Avoid the L2 tables update for the images that have snapshots.
if (!s->is_parent) {
status = stat(s->hd->filename, &file_buf);
if (status == -1) {
fprintf(stderr, "(VMDK) Fail file stat: filename =%s size=0x%lx errno=%s\n",
s->hd->filename, (uint64_t)file_buf.st_size, strerror(errno));
return 0;
}
cluster_offset = file_buf.st_size;
bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
cluster_offset >>= 9;
tmp = cpu_to_le32(cluster_offset);
l2_table[l2_index] = tmp;
// Save the active image state
activeBDRV.cluster_offset = cluster_offset;
activeBDRV.hd = bs;
}
/* 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.
*/
if (get_whole_cluster(bs, cluster_offset, offset, allocate) == -1)
return 0;
if (m_data) {
m_data->offset = tmp;
m_data->l1_index = l1_index;
m_data->l2_index = l2_index;
m_data->l2_offset = l2_offset;
m_data->valid = 1;
}
}
cluster_offset <<= 9;
return cluster_offset;
}
static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
BDRVVmdkState *s = bs->opaque;
int index_in_cluster, n;
uint64_t cluster_offset;
cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
index_in_cluster = sector_num % s->cluster_sectors;
n = s->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
*pnum = n;
return (cluster_offset != 0);
}
static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BDRVVmdkState *s = bs->opaque;
int index_in_cluster, n, ret;
uint64_t cluster_offset;
while (nb_sectors > 0) {
cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
index_in_cluster = sector_num % s->cluster_sectors;
n = s->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
if (!cluster_offset) {
// try to read from parent image, if exist
if (s->hd->backing_hd) {
if (!vmdk_is_cid_valid(bs))
return -1;
ret = bdrv_read(s->hd->backing_hd, sector_num, buf, n);
if (ret < 0)
return -1;
} else {
memset(buf, 0, 512 * n);
}
} else {
if(bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
return -1;
}
nb_sectors -= n;
sector_num += n;
buf += n * 512;
}
return 0;
}
static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
BDRVVmdkState *s = bs->opaque;
VmdkMetaData m_data;
int index_in_cluster, n;
uint64_t cluster_offset;
static int cid_update = 0;
if (sector_num > bs->total_sectors) {
fprintf(stderr,
"(VMDK) Wrong offset: sector_num=0x%lx total_sectors=0x%lx\n",
sector_num, bs->total_sectors);
return -1;
}
while (nb_sectors > 0) {
index_in_cluster = sector_num & (s->cluster_sectors - 1);
n = s->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
cluster_offset = get_cluster_offset(bs, &m_data, sector_num << 9, 1);
if (!cluster_offset)
return -1;
if (bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
return -1;
if (m_data.valid) {
/* update L2 tables */
if (vmdk_L2update(bs, &m_data) == -1)
return -1;
}
nb_sectors -= n;
sector_num += n;
buf += n * 512;
// update CID on the first write every time the virtual disk is opened
if (!cid_update) {
vmdk_write_cid(bs, time(NULL));
cid_update++;
}
}
return 0;
}
static int vmdk_create(const char *filename, int64_t total_size,
const char *backing_file, int flags)
{
int fd, i;
VMDK4Header header;
uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
char *desc_template =
"# Disk DescriptorFile\n"
"version=1\n"
"CID=%x\n"
"parentCID=ffffffff\n"
"createType=\"monolithicSparse\"\n"
"\n"
"# Extent description\n"
"RW %lu SPARSE \"%s\"\n"
"\n"
"# The Disk Data Base \n"
"#DDB\n"
"\n"
"ddb.virtualHWVersion = \"4\"\n"
"ddb.geometry.cylinders = \"%lu\"\n"
"ddb.geometry.heads = \"16\"\n"
"ddb.geometry.sectors = \"63\"\n"
"ddb.adapterType = \"ide\"\n";
char desc[1024];
const char *real_filename, *temp_str;
/* XXX: add support for backing file */
if (backing_file) {
return vmdk_snapshot_create(filename, backing_file);
}
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
0644);
if (fd < 0)
return -1;
magic = cpu_to_be32(VMDK4_MAGIC);
memset(&header, 0, sizeof(header));
header.version = cpu_to_le32(1);
header.flags = cpu_to_le32(3); /* ?? */
header.capacity = cpu_to_le64(total_size);
header.granularity = cpu_to_le64(128);
header.num_gtes_per_gte = cpu_to_le32(512);
grains = (total_size + header.granularity - 1) / header.granularity;
gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
gt_count = (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
header.desc_offset = 1;
header.desc_size = 20;
header.rgd_offset = header.desc_offset + header.desc_size;
header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
header.grain_offset =
((header.gd_offset + gd_size + (gt_size * gt_count) +
header.granularity - 1) / header.granularity) *
header.granularity;
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.check_bytes[0] = 0xa;
header.check_bytes[1] = 0x20;
header.check_bytes[2] = 0xd;
header.check_bytes[3] = 0xa;
/* write all the data */
write(fd, &magic, sizeof(magic));
write(fd, &header, sizeof(header));
ftruncate(fd, header.grain_offset << 9);
/* write grain directory */
lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
for (i = 0, tmp = header.rgd_offset + gd_size;
i < gt_count; i++, tmp += gt_size)
write(fd, &tmp, sizeof(tmp));
/* write backup grain directory */
lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
for (i = 0, tmp = header.gd_offset + gd_size;
i < gt_count; i++, tmp += gt_size)
write(fd, &tmp, sizeof(tmp));
/* compose the descriptor */
real_filename = filename;
if ((temp_str = strrchr(real_filename, '\\')) != NULL)
real_filename = temp_str + 1;
if ((temp_str = strrchr(real_filename, '/')) != NULL)
real_filename = temp_str + 1;
if ((temp_str = strrchr(real_filename, ':')) != NULL)
real_filename = temp_str + 1;
sprintf(desc, desc_template, time(NULL), (unsigned long)total_size,
real_filename, total_size / (63 * 16));
/* write the descriptor */
lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
write(fd, desc, strlen(desc));
close(fd);
return 0;
}
static void vmdk_close(BlockDriverState *bs)
{
BDRVVmdkState *s = bs->opaque;
qemu_free(s->l1_table);
qemu_free(s->l2_cache);
bdrv_delete(s->hd);
// try to close parent image, if exist
vmdk_parent_close(s->hd);
}
static void vmdk_flush(BlockDriverState *bs)
{
BDRVVmdkState *s = bs->opaque;
bdrv_flush(s->hd);
}
BlockDriver bdrv_vmdk = {
"vmdk",
sizeof(BDRVVmdkState),
vmdk_probe,
vmdk_open,
vmdk_read,
vmdk_write,
vmdk_close,
vmdk_create,
vmdk_flush,
vmdk_is_allocated,
};
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