mirrors/qemu
0
0
Fork 0
mirror of https://github.com/qemu/qemu.git synced 2024-11-24 19:33:39 +08:00
Code Issues Packages Projects Releases Wiki Activity
91b85bd388
qemu/block/vmdk.c
Fam Zheng 91b85bd388 VMDK: change get_cluster_offset return type 
The return type of get_cluster_offset was an offset that use 0 to denote
'not allocated', this will be no longer true for flat extents, as we see
flat extent file as a single huge cluster whose offset is 0 and length
is the whole file length.
So now we use int return value, 0 means success and otherwise offset
invalid.

Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-19 15:39:07 +02:00

1134 lines
32 KiB
C
Raw Blame History

/*
* 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-common.h"
#include "block_int.h"
#include "module.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 VmdkExtent {
BlockDriverState *file;
bool flat;
int64_t sectors;
int64_t end_sector;
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;
} VmdkExtent;
typedef struct BDRVVmdkState {
int desc_offset;
bool cid_updated;
uint32_t parent_cid;
int num_extents;
/* Extent array with num_extents entries, ascend ordered by address */
VmdkExtent *extents;
} BDRVVmdkState;
typedef struct VmdkMetaData {
uint32_t offset;
unsigned int l1_index;
unsigned int l2_index;
unsigned int l2_offset;
int valid;
} VmdkMetaData;
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) {
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) {
return 100;
}
}
return 0;
}
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 void vmdk_free_extents(BlockDriverState *bs)
{
int i;
BDRVVmdkState *s = bs->opaque;
for (i = 0; i < s->num_extents; i++) {
qemu_free(s->extents[i].l1_table);
qemu_free(s->extents[i].l2_cache);
qemu_free(s->extents[i].l1_backup_table);
}
qemu_free(s->extents);
}
static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
{
char desc[DESC_SIZE];
uint32_t cid;
const char *p_name, *cid_str;
size_t cid_str_size;
BDRVVmdkState *s = bs->opaque;
if (bdrv_pread(bs->file, s->desc_offset, 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)) != NULL) {
p_name += cid_str_size;
sscanf(p_name,"%x",&cid);
}
return cid;
}
static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
{
char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
char *p_name, *tmp_str;
BDRVVmdkState *s = bs->opaque;
memset(desc, 0, sizeof(desc));
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return -EIO;
}
tmp_str = strstr(desc,"parentCID");
pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);
if ((p_name = strstr(desc,"CID")) != NULL) {
p_name += sizeof("CID");
snprintf(p_name, sizeof(desc) - (p_name - desc), "%x\n", cid);
pstrcat(desc, sizeof(desc), tmp_desc);
}
if (bdrv_pwrite_sync(bs->file, s->desc_offset, desc, DESC_SIZE) < 0) {
return -EIO;
}
return 0;
}
static int vmdk_is_cid_valid(BlockDriverState *bs)
{
#ifdef CHECK_CID
BDRVVmdkState *s = bs->opaque;
BlockDriverState *p_bs = bs->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;
int ret;
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];
static const 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 %u 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 -errno;
p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
if (p_fd < 0) {
close(snp_fd);
return -errno;
}
/* read the header */
if (lseek(p_fd, 0x0, SEEK_SET) == -1) {
ret = -errno;
goto fail;
}
if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE) {
ret = -errno;
goto fail;
}
/* write the header */
if (lseek(snp_fd, 0x0, SEEK_SET) == -1) {
ret = -errno;
goto fail;
}
if (write(snp_fd, hdr, HEADER_SIZE) == -1) {
ret = -errno;
goto fail;
}
memset(&header, 0, sizeof(header));
memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
if (ftruncate(snp_fd, header.grain_offset << 9)) {
ret = -errno;
goto fail;
}
/* the descriptor offset = 0x200 */
if (lseek(p_fd, 0x200, SEEK_SET) == -1) {
ret = -errno;
goto fail;
}
if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE) {
ret = -errno;
goto fail;
}
if ((p_name = strstr(p_desc,"CID")) != NULL) {
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;
snprintf(s_desc, sizeof(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) {
ret = -errno;
goto fail;
}
if (write(snp_fd, s_desc, strlen(s_desc)) == -1) {
ret = -errno;
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) {
ret = -EINVAL;
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 (lseek(p_fd, rgd_offset, SEEK_SET) == -1) {
ret = -errno;
goto fail_rgd;
}
if (read(p_fd, rgd_buf, gd_size) != gd_size) {
ret = -errno;
goto fail_rgd;
}
if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1) {
ret = -errno;
goto fail_rgd;
}
if (write(snp_fd, rgd_buf, gd_size) == -1) {
ret = -errno;
goto fail_rgd;
}
/* write GD */
gd_buf = qemu_malloc(gd_size);
if (lseek(p_fd, gd_offset, SEEK_SET) == -1) {
ret = -errno;
goto fail_gd;
}
if (read(p_fd, gd_buf, gd_size) != gd_size) {
ret = -errno;
goto fail_gd;
}
if (lseek(snp_fd, gd_offset, SEEK_SET) == -1) {
ret = -errno;
goto fail_gd;
}
if (write(snp_fd, gd_buf, gd_size) == -1) {
ret = -errno;
goto fail_gd;
}
ret = 0;
fail_gd:
qemu_free(gd_buf);
fail_rgd:
qemu_free(rgd_buf);
fail:
close(p_fd);
close(snp_fd);
return ret;
}
static int vmdk_parent_open(BlockDriverState *bs)
{
char *p_name;
char desc[DESC_SIZE];
BDRVVmdkState *s = bs->opaque;
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return -1;
}
if ((p_name = strstr(desc,"parentFileNameHint")) != NULL) {
char *end_name;
p_name += sizeof("parentFileNameHint") + 1;
if ((end_name = strchr(p_name,'\"')) == NULL)
return -1;
if ((end_name - p_name) > sizeof (bs->backing_file) - 1)
return -1;
pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
}
return 0;
}
/* Create and append extent to the extent array. Return the added VmdkExtent
* address. return NULL if allocation failed. */
static VmdkExtent *vmdk_add_extent(BlockDriverState *bs,
BlockDriverState *file, bool flat, int64_t sectors,
int64_t l1_offset, int64_t l1_backup_offset,
uint32_t l1_size,
int l2_size, unsigned int cluster_sectors)
{
VmdkExtent *extent;
BDRVVmdkState *s = bs->opaque;
s->extents = qemu_realloc(s->extents,
(s->num_extents + 1) * sizeof(VmdkExtent));
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 = cluster_sectors;
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;
return extent;
}
static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent)
{
int ret;
int l1_size, i;
/* read the L1 table */
l1_size = extent->l1_size * sizeof(uint32_t);
extent->l1_table = qemu_malloc(l1_size);
ret = bdrv_pread(extent->file,
extent->l1_table_offset,
extent->l1_table,
l1_size);
if (ret < 0) {
goto fail_l1;
}
for (i = 0; i < extent->l1_size; i++) {
le32_to_cpus(&extent->l1_table[i]);
}
if (extent->l1_backup_table_offset) {
extent->l1_backup_table = qemu_malloc(l1_size);
ret = bdrv_pread(extent->file,
extent->l1_backup_table_offset,
extent->l1_backup_table,
l1_size);
if (ret < 0) {
goto fail_l1b;
}
for (i = 0; i < extent->l1_size; i++) {
le32_to_cpus(&extent->l1_backup_table[i]);
}
}
extent->l2_cache =
qemu_malloc(extent->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
return 0;
fail_l1b:
qemu_free(extent->l1_backup_table);
fail_l1:
qemu_free(extent->l1_table);
return ret;
}
static int vmdk_open_vmdk3(BlockDriverState *bs, int flags)
{
int ret;
uint32_t magic;
VMDK3Header header;
BDRVVmdkState *s = bs->opaque;
VmdkExtent *extent;
s->desc_offset = 0x200;
ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
if (ret < 0) {
goto fail;
}
extent = vmdk_add_extent(bs,
bs->file, false,
le32_to_cpu(header.disk_sectors),
le32_to_cpu(header.l1dir_offset) << 9,
0, 1 << 6, 1 << 9,
le32_to_cpu(header.granularity));
ret = vmdk_init_tables(bs, extent);
if (ret) {
/* vmdk_init_tables cleans up on fail, so only free allocation of
* vmdk_add_extent here. */
goto fail;
}
return 0;
fail:
vmdk_free_extents(bs);
return ret;
}
static int vmdk_open_vmdk4(BlockDriverState *bs, int flags)
{
int ret;
uint32_t magic;
uint32_t l1_size, l1_entry_sectors;
VMDK4Header header;
BDRVVmdkState *s = bs->opaque;
VmdkExtent *extent;
s->desc_offset = 0x200;
ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
if (ret < 0) {
goto fail;
}
l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gte)
* le64_to_cpu(header.granularity);
l1_size = (le64_to_cpu(header.capacity) + l1_entry_sectors - 1)
/ l1_entry_sectors;
extent = vmdk_add_extent(bs, bs->file, false,
le64_to_cpu(header.capacity),
le64_to_cpu(header.gd_offset) << 9,
le64_to_cpu(header.rgd_offset) << 9,
l1_size,
le32_to_cpu(header.num_gtes_per_gte),
le64_to_cpu(header.granularity));
if (extent->l1_entry_sectors <= 0) {
ret = -EINVAL;
goto fail;
}
/* try to open parent images, if exist */
ret = vmdk_parent_open(bs);
if (ret) {
goto fail;
}
s->parent_cid = vmdk_read_cid(bs, 1);
ret = vmdk_init_tables(bs, extent);
if (ret) {
goto fail;
}
return 0;
fail:
vmdk_free_extents(bs);
return ret;
}
static int vmdk_open(BlockDriverState *bs, int flags)
{
uint32_t magic;
if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic)) {
return -EIO;
}
magic = be32_to_cpu(magic);
if (magic == VMDK3_MAGIC) {
return vmdk_open_vmdk3(bs, flags);
} else if (magic == VMDK4_MAGIC) {
return vmdk_open_vmdk4(bs, flags);
} else {
return -EINVAL;
}
}
static int get_whole_cluster(BlockDriverState *bs,
VmdkExtent *extent,
uint64_t cluster_offset,
uint64_t offset,
bool allocate)
{
/* 128 sectors * 512 bytes each = grain size 64KB */
uint8_t whole_grain[extent->cluster_sectors * 512];
/* 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_hd) {
int ret;
if (!vmdk_is_cid_valid(bs))
return -1;
/* floor offset to cluster */
offset -= offset % (extent->cluster_sectors * 512);
ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain,
extent->cluster_sectors);
if (ret < 0) {
return -1;
}
/* Write grain only into the active image */
ret = bdrv_write(extent->file, cluster_offset, whole_grain,
extent->cluster_sectors);
if (ret < 0) {
return -1;
}
}
return 0;
}
static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data)
{
/* update L2 table */
if (bdrv_pwrite_sync(
extent->file,
((int64_t)m_data->l2_offset * 512)
+ (m_data->l2_index * sizeof(m_data->offset)),
&(m_data->offset),
sizeof(m_data->offset)
) < 0) {
return -1;
}
/* 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_sync(
extent->file,
((int64_t)m_data->l2_offset * 512)
+ (m_data->l2_index * sizeof(m_data->offset)),
&(m_data->offset), sizeof(m_data->offset)
) < 0) {
return -1;
}
}
return 0;
}
static int get_cluster_offset(BlockDriverState *bs,
VmdkExtent *extent,
VmdkMetaData *m_data,
uint64_t offset,
int allocate,
uint64_t *cluster_offset)
{
unsigned int l1_index, l2_offset, l2_index;
int min_index, i, j;
uint32_t min_count, *l2_table, tmp = 0;
if (m_data)
m_data->valid = 0;
if (extent->flat) {
*cluster_offset = 0;
return 0;
}
l1_index = (offset >> 9) / extent->l1_entry_sectors;
if (l1_index >= extent->l1_size) {
return -1;
}
l2_offset = extent->l1_table[l1_index];
if (!l2_offset) {
return -1;
}
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 = extent->l2_cache + (i * extent->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 (extent->l2_cache_counts[i] < min_count) {
min_count = extent->l2_cache_counts[i];
min_index = i;
}
}
l2_table = extent->l2_cache + (min_index * extent->l2_size);
if (bdrv_pread(
extent->file,
(int64_t)l2_offset * 512,
l2_table,
extent->l2_size * sizeof(uint32_t)
) != extent->l2_size * sizeof(uint32_t)) {
return -1;
}
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;
*cluster_offset = le32_to_cpu(l2_table[l2_index]);
if (!*cluster_offset) {
if (!allocate) {
return -1;
}
// Avoid the L2 tables update for the images that have snapshots.
*cluster_offset = bdrv_getlength(extent->file);
bdrv_truncate(
extent->file,
*cluster_offset + (extent->cluster_sectors << 9)
);
*cluster_offset >>= 9;
tmp = cpu_to_le32(*cluster_offset);
l2_table[l2_index] = tmp;
/* 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, extent, *cluster_offset, offset, allocate) == -1)
return -1;
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 0;
}
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 int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
BDRVVmdkState *s = bs->opaque;
int64_t index_in_cluster, n, ret;
uint64_t offset;
VmdkExtent *extent;
extent = find_extent(s, sector_num, NULL);
if (!extent) {
return 0;
}
ret = get_cluster_offset(bs, extent, NULL,
sector_num * 512, 0, &offset);
/* get_cluster_offset returning 0 means success */
ret = !ret;
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
*pnum = n;
return ret;
}
static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BDRVVmdkState *s = bs->opaque;
int ret;
uint64_t n, index_in_cluster;
VmdkExtent *extent = NULL;
uint64_t cluster_offset;
while (nb_sectors > 0) {
extent = find_extent(s, sector_num, extent);
if (!extent) {
return -EIO;
}
ret = get_cluster_offset(
bs, extent, NULL,
sector_num << 9, 0, &cluster_offset);
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
if (ret) {
/* if not allocated, try to read from parent image, if exist */
if (bs->backing_hd) {
if (!vmdk_is_cid_valid(bs))
return -1;
ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
if (ret < 0)
return -1;
} else {
memset(buf, 0, 512 * n);
}
} else {
if(bdrv_pread(bs->file, 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;
VmdkExtent *extent = NULL;
int n, ret;
int64_t index_in_cluster;
uint64_t cluster_offset;
VmdkMetaData m_data;
if (sector_num > bs->total_sectors) {
fprintf(stderr,
"(VMDK) Wrong offset: sector_num=0x%" PRIx64
" total_sectors=0x%" PRIx64 "\n",
sector_num, bs->total_sectors);
return -1;
}
while (nb_sectors > 0) {
extent = find_extent(s, sector_num, extent);
if (!extent) {
return -EIO;
}
ret = get_cluster_offset(
bs,
extent,
&m_data,
sector_num << 9, 1,
&cluster_offset);
if (ret) {
return -EINVAL;
}
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors) {
n = nb_sectors;
}
if (bdrv_pwrite(bs->file,
cluster_offset + index_in_cluster * 512,
buf, n * 512)
!= n * 512) {
return -1;
}
if (m_data.valid) {
/* update L2 tables */
if (vmdk_L2update(extent, &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 (!s->cid_updated) {
vmdk_write_cid(bs, time(NULL));
s->cid_updated = true;
}
}
return 0;
}
static int vmdk_create(const char *filename, QEMUOptionParameter *options)
{
int fd, i;
VMDK4Header header;
uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
static const char desc_template[] =
"# Disk DescriptorFile\n"
"version=1\n"
"CID=%x\n"
"parentCID=ffffffff\n"
"createType=\"monolithicSparse\"\n"
"\n"
"# Extent description\n"
"RW %" PRId64 " SPARSE \"%s\"\n"
"\n"
"# The Disk Data Base \n"
"#DDB\n"
"\n"
"ddb.virtualHWVersion = \"%d\"\n"
"ddb.geometry.cylinders = \"%" PRId64 "\"\n"
"ddb.geometry.heads = \"16\"\n"
"ddb.geometry.sectors = \"63\"\n"
"ddb.adapterType = \"ide\"\n";
char desc[1024];
const char *real_filename, *temp_str;
int64_t total_size = 0;
const char *backing_file = NULL;
int flags = 0;
int ret;
// Read out options
while (options && options->name) {
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
total_size = options->value.n / 512;
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
backing_file = options->value.s;
} else if (!strcmp(options->name, BLOCK_OPT_COMPAT6)) {
flags |= options->value.n ? BLOCK_FLAG_COMPAT6: 0;
}
options++;
}
/* 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 -errno;
magic = cpu_to_be32(VMDK4_MAGIC);
memset(&header, 0, sizeof(header));
header.version = 1;
header.flags = 3; /* ?? */
header.capacity = total_size;
header.granularity = 128;
header.num_gtes_per_gte = 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;
/* 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_gte = cpu_to_le32(header.num_gtes_per_gte);
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 */
ret = qemu_write_full(fd, &magic, sizeof(magic));
if (ret != sizeof(magic)) {
ret = -errno;
goto exit;
}
ret = qemu_write_full(fd, &header, sizeof(header));
if (ret != sizeof(header)) {
ret = -errno;
goto exit;
}
ret = ftruncate(fd, le64_to_cpu(header.grain_offset) << 9);
if (ret < 0) {
ret = -errno;
goto exit;
}
/* write grain directory */
lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
for (i = 0, tmp = le64_to_cpu(header.rgd_offset) + gd_size;
i < gt_count; i++, tmp += gt_size) {
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
if (ret != sizeof(tmp)) {
ret = -errno;
goto exit;
}
}
/* write backup grain directory */
lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
for (i = 0, tmp = le64_to_cpu(header.gd_offset) + gd_size;
i < gt_count; i++, tmp += gt_size) {
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
if (ret != sizeof(tmp)) {
ret = -errno;
goto exit;
}
}
/* 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;
snprintf(desc, sizeof(desc), desc_template, (unsigned int)time(NULL),
total_size, real_filename,
(flags & BLOCK_FLAG_COMPAT6 ? 6 : 4),
total_size / (int64_t)(63 * 16));
/* write the descriptor */
lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
ret = qemu_write_full(fd, desc, strlen(desc));
if (ret != strlen(desc)) {
ret = -errno;
goto exit;
}
ret = 0;
exit:
close(fd);
return ret;
}
static void vmdk_close(BlockDriverState *bs)
{
vmdk_free_extents(bs);
}
static int vmdk_flush(BlockDriverState *bs)
{
int i, ret, err;
BDRVVmdkState *s = bs->opaque;
ret = bdrv_flush(bs->file);
for (i = 0; i < s->num_extents; i++) {
err = bdrv_flush(s->extents[i].file);
if (err < 0) {
ret = err;
}
}
return ret;
}
static QEMUOptionParameter vmdk_create_options[] = {
{
.name = BLOCK_OPT_SIZE,
.type = OPT_SIZE,
.help = "Virtual disk size"
},
{
.name = BLOCK_OPT_BACKING_FILE,
.type = OPT_STRING,
.help = "File name of a base image"
},
{
.name = BLOCK_OPT_COMPAT6,
.type = OPT_FLAG,
.help = "VMDK version 6 image"
},
{ NULL }
};
static BlockDriver bdrv_vmdk = {
.format_name = "vmdk",
.instance_size = sizeof(BDRVVmdkState),
.bdrv_probe = vmdk_probe,
.bdrv_open = vmdk_open,
.bdrv_read = vmdk_read,
.bdrv_write = vmdk_write,
.bdrv_close = vmdk_close,
.bdrv_create = vmdk_create,
.bdrv_flush = vmdk_flush,
.bdrv_is_allocated = vmdk_is_allocated,
.create_options = vmdk_create_options,
};
static void bdrv_vmdk_init(void)
{
bdrv_register(&bdrv_vmdk);
}
block_init(bdrv_vmdk_init);
Reference in New Issue View Git Blame Copy Permalink