mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
de33b1f3dd
qemu/block/vmdk.c
Anthony Liguori 7267c0947d Use glib memory allocation and free functions 
qemu_malloc/qemu_free no longer exist after this commit.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20 23:01:08 -05:00

1364 lines
38 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 flat_start_offset;
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 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;
for (i = 0; i < s->num_extents; i++) {
g_free(s->extents[i].l1_table);
g_free(s->extents[i].l2_cache);
g_free(s->extents[i].l1_backup_table);
}
g_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");
}
p_name = strstr(desc, cid_str);
if (p_name != 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);
p_name = strstr(desc, "CID");
if (p_name != 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_parent_open(BlockDriverState *bs)
{
char *p_name;
char desc[DESC_SIZE + 1];
BDRVVmdkState *s = bs->opaque;
desc[DESC_SIZE] = '\0';
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return -1;
}
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) {
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 = g_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 = g_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 = g_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 =
g_malloc(extent->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
return 0;
fail_l1b:
g_free(extent->l1_backup_table);
fail_l1:
g_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;
}
/* 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 -1;
}
/* Skip "=\"" following opt_name */
opt_pos += strlen(opt_name) + 2;
if (opt_pos >= end) {
return -1;
}
opt_end = opt_pos;
while (opt_end < end && *opt_end != '"') {
opt_end++;
}
if (opt_end == end || buf_size < opt_end - opt_pos + 1) {
return -1;
}
pstrcpy(buf, opt_end - opt_pos + 1, opt_pos);
return 0;
}
static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
const char *desc_file_path)
{
int ret;
char access[11];
char type[11];
char fname[512];
const char *p = desc;
int64_t sectors = 0;
int64_t flat_offset;
while (*p) {
/* parse extent line:
* RW [size in sectors] FLAT "file-name.vmdk" OFFSET
* or
* RW [size in sectors] SPARSE "file-name.vmdk"
*/
flat_offset = -1;
ret = sscanf(p, "%10s %" SCNd64 " %10s %511s %" SCNd64,
access, &sectors, type, fname, &flat_offset);
if (ret < 4 || strcmp(access, "RW")) {
goto next_line;
} else if (!strcmp(type, "FLAT")) {
if (ret != 5 || flat_offset < 0) {
return -EINVAL;
}
} else if (ret != 4) {
return -EINVAL;
}
/* trim the quotation marks around */
if (fname[0] == '"') {
memmove(fname, fname + 1, strlen(fname));
if (strlen(fname) <= 1 || fname[strlen(fname) - 1] != '"') {
return -EINVAL;
}
fname[strlen(fname) - 1] = '\0';
}
if (sectors <= 0 ||
(strcmp(type, "FLAT") && strcmp(type, "SPARSE")) ||
(strcmp(access, "RW"))) {
goto next_line;
}
/* save to extents array */
if (!strcmp(type, "FLAT")) {
/* FLAT extent */
char extent_path[PATH_MAX];
BlockDriverState *extent_file;
VmdkExtent *extent;
path_combine(extent_path, sizeof(extent_path),
desc_file_path, fname);
ret = bdrv_file_open(&extent_file, extent_path, bs->open_flags);
if (ret) {
return ret;
}
extent = vmdk_add_extent(bs, extent_file, true, sectors,
0, 0, 0, 0, sectors);
extent->flat_start_offset = flat_offset;
} else {
/* SPARSE extent, not supported for now */
fprintf(stderr,
"VMDK: Not supported extent type \"%s\""".\n", type);
return -ENOTSUP;
}
next_line:
/* move to next line */
while (*p && *p != '\n') {
p++;
}
p++;
}
return 0;
}
static int vmdk_open_desc_file(BlockDriverState *bs, int flags)
{
int ret;
char buf[2048];
char ct[128];
BDRVVmdkState *s = bs->opaque;
ret = bdrv_pread(bs->file, 0, buf, sizeof(buf));
if (ret < 0) {
return ret;
}
buf[2047] = '\0';
if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
return -EINVAL;
}
if (strcmp(ct, "monolithicFlat")) {
fprintf(stderr,
"VMDK: Not supported image type \"%s\""".\n", ct);
return -ENOTSUP;
}
s->desc_offset = 0;
ret = vmdk_parse_extents(buf, bs, bs->file->filename);
if (ret) {
return ret;
}
/* try to open parent images, if exist */
if (vmdk_parent_open(bs)) {
g_free(s->extents);
return -EINVAL;
}
s->parent_cid = vmdk_read_cid(bs, 1);
return 0;
}
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 vmdk_open_desc_file(bs, flags);
}
}
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 = extent->flat_start_offset;
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 -EINVAL;
}
ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
if (ret < 0) {
return ret;
}
} else {
memset(buf, 0, 512 * n);
}
} else {
ret = bdrv_pread(extent->file,
cluster_offset + index_in_cluster * 512,
buf, n * 512);
if (ret < 0) {
return ret;
}
}
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 -EIO;
}
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;
}
ret = bdrv_pwrite(extent->file,
cluster_offset + index_in_cluster * 512,
buf,
n * 512);
if (ret < 0) {
return ret;
}
if (m_data.valid) {
/* update L2 tables */
if (vmdk_L2update(extent, &m_data) == -1) {
return -EIO;
}
}
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_extent(const char *filename, int64_t filesize, bool flat)
{
int ret, i;
int fd = 0;
VMDK4Header header;
uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
fd = open(
filename,
O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
0644);
if (fd < 0) {
return -errno;
}
if (flat) {
ret = ftruncate(fd, filesize);
if (ret < 0) {
ret = -errno;
}
goto exit;
}
magic = cpu_to_be32(VMDK4_MAGIC);
memset(&header, 0, sizeof(header));
header.version = 1;
header.flags = 3; /* ?? */
header.capacity = filesize / 512;
header.granularity = 128;
header.num_gtes_per_gte = 512;
grains = (filesize / 512 + 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;
}
}
ret = 0;
exit:
close(fd);
return ret;
}
static int filename_decompose(const char *filename, char *path, char *prefix,
char *postfix, size_t buf_len)
{
const char *p, *q;
if (filename == NULL || !strlen(filename)) {
fprintf(stderr, "Vmdk: no filename provided.\n");
return -1;
}
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 -1;
}
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 -1;
}
pstrcpy(prefix, q - p + 1, p);
pstrcpy(postfix, buf_len, q);
}
return 0;
}
static int relative_path(char *dest, int dest_size,
const char *base, const char *target)
{
int i = 0;
int n = 0;
const char *p, *q;
#ifdef _WIN32
const char *sep = "\\";
#else
const char *sep = "/";
#endif
if (!(dest && base && target)) {
return -1;
}
if (path_is_absolute(target)) {
dest[dest_size - 1] = '\0';
strncpy(dest, target, dest_size - 1);
return 0;
}
while (base[i] == target[i]) {
i++;
}
p = &base[i];
q = &target[i];
while (*p) {
if (*p == *sep) {
n++;
}
p++;
}
dest[0] = '\0';
for (; n; n--) {
pstrcat(dest, dest_size, "..");
pstrcat(dest, dest_size, sep);
}
pstrcat(dest, dest_size, q);
return 0;
}
static int vmdk_create(const char *filename, QEMUOptionParameter *options)
{
int fd, idx = 0;
char desc[BUF_SIZE];
int64_t total_size = 0, filesize;
const char *backing_file = NULL;
const char *fmt = NULL;
int flags = 0;
int ret = 0;
bool flat, split;
char ext_desc_lines[BUF_SIZE] = "";
char path[PATH_MAX], prefix[PATH_MAX], postfix[PATH_MAX];
const int64_t split_size = 0x80000000; /* VMDK has constant split size */
const char *desc_extent_line;
char parent_desc_line[BUF_SIZE] = "";
uint32_t parent_cid = 0xffffffff;
const char desc_template[] =
"# Disk DescriptorFile\n"
"version=1\n"
"CID=%x\n"
"parentCID=%x\n"
"createType=\"%s\"\n"
"%s"
"\n"
"# Extent description\n"
"%s"
"\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";
if (filename_decompose(filename, path, prefix, postfix, PATH_MAX)) {
return -EINVAL;
}
/* Read out options */
while (options && options->name) {
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
total_size = options->value.n;
} 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;
} else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) {
fmt = options->value.s;
}
options++;
}
if (!fmt) {
/* Default format to monolithicSparse */
fmt = "monolithicSparse";
} else if (strcmp(fmt, "monolithicFlat") &&
strcmp(fmt, "monolithicSparse") &&
strcmp(fmt, "twoGbMaxExtentSparse") &&
strcmp(fmt, "twoGbMaxExtentFlat")) {
fprintf(stderr, "VMDK: Unknown subformat: %s\n", fmt);
return -EINVAL;
}
split = !(strcmp(fmt, "twoGbMaxExtentFlat") &&
strcmp(fmt, "twoGbMaxExtentSparse"));
flat = !(strcmp(fmt, "monolithicFlat") &&
strcmp(fmt, "twoGbMaxExtentFlat"));
if (flat) {
desc_extent_line = "RW %lld FLAT \"%s\" 0\n";
} else {
desc_extent_line = "RW %lld SPARSE \"%s\"\n";
}
if (flat && backing_file) {
/* not supporting backing file for flat image */
return -ENOTSUP;
}
if (backing_file) {
char parent_filename[PATH_MAX];
BlockDriverState *bs = bdrv_new("");
ret = bdrv_open(bs, backing_file, 0, NULL);
if (ret != 0) {
bdrv_delete(bs);
return ret;
}
if (strcmp(bs->drv->format_name, "vmdk")) {
bdrv_delete(bs);
return -EINVAL;
}
filesize = bdrv_getlength(bs);
parent_cid = vmdk_read_cid(bs, 0);
bdrv_delete(bs);
relative_path(parent_filename, sizeof(parent_filename),
filename, backing_file);
snprintf(parent_desc_line, sizeof(parent_desc_line),
"parentFileNameHint=\"%s\"", parent_filename);
}
/* Create extents */
filesize = total_size;
while (filesize > 0) {
char desc_line[BUF_SIZE];
char ext_filename[PATH_MAX];
char desc_filename[PATH_MAX];
int64_t size = filesize;
if (split && size > split_size) {
size = split_size;
}
if (split) {
snprintf(desc_filename, sizeof(desc_filename), "%s-%c%03d%s",
prefix, flat ? 'f' : 's', ++idx, postfix);
} else if (flat) {
snprintf(desc_filename, sizeof(desc_filename), "%s-flat%s",
prefix, postfix);
} else {
snprintf(desc_filename, sizeof(desc_filename), "%s%s",
prefix, postfix);
}
snprintf(ext_filename, sizeof(ext_filename), "%s%s",
path, desc_filename);
if (vmdk_create_extent(ext_filename, size, flat)) {
return -EINVAL;
}
filesize -= size;
/* Format description line */
snprintf(desc_line, sizeof(desc_line),
desc_extent_line, size / 512, desc_filename);
pstrcat(ext_desc_lines, sizeof(ext_desc_lines), desc_line);
}
/* generate descriptor file */
snprintf(desc, sizeof(desc), desc_template,
(unsigned int)time(NULL),
parent_cid,
fmt,
parent_desc_line,
ext_desc_lines,
(flags & BLOCK_FLAG_COMPAT6 ? 6 : 4),
total_size / (int64_t)(63 * 16 * 512));
if (split || flat) {
fd = open(
filename,
O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
0644);
} else {
fd = open(
filename,
O_WRONLY | O_BINARY | O_LARGEFILE,
0644);
}
if (fd < 0) {
return -errno;
}
/* the descriptor offset = 0x200 */
if (!split && !flat && 0x200 != lseek(fd, 0x200, SEEK_SET)) {
ret = -errno;
goto exit;
}
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 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);
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);
if (r < 0) {
return r;
}
ret += r;
}
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"
},
{
.name = BLOCK_OPT_SUBFMT,
.type = OPT_STRING,
.help =
"VMDK flat extent format, can be one of "
"{monolithicSparse (default) | monolithicFlat | twoGbMaxExtentSparse | twoGbMaxExtentFlat} "
},
{ 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,
.bdrv_get_allocated_file_size = vmdk_get_allocated_file_size,
.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