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qemu/block/vdi.c
Max Reitz d20418ee51 block/vdi: Limit maximum size even futher 
The block layer read and write functions do not like requests which are
bigger than INT_MAX bytes. Since the VDI bmap is read and written in a
single operation, its size is therefore limited accordingly. This
reduces the maximum VDI image size supported by QEMU to half of what it
currently is (down to approximately 512 TB).

The VDI test 084 has to be adapted accordingly. Actually, one could
clearly see that it was broken from the "Could not open
'TEST_DIR/t.IMGFMT': Invalid argument" line for an image which was
supposed to work just fine.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
2014-11-09 23:39:50 +01:00

895 lines
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/*
* Block driver for the Virtual Disk Image (VDI) format
*
* Copyright (c) 2009, 2012 Stefan Weil
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) version 3 or any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Reference:
* http://forums.virtualbox.org/viewtopic.php?t=8046
*
* This driver supports create / read / write operations on VDI images.
*
* Todo (see also TODO in code):
*
* Some features like snapshots are still missing.
*
* Deallocation of zero-filled blocks and shrinking images are missing, too
* (might be added to common block layer).
*
* Allocation of blocks could be optimized (less writes to block map and
* header).
*
* Read and write of adjacent blocks could be done in one operation
* (current code uses one operation per block (1 MiB).
*
* The code is not thread safe (missing locks for changes in header and
* block table, no problem with current QEMU).
*
* Hints:
*
* Blocks (VDI documentation) correspond to clusters (QEMU).
* QEMU's backing files could be implemented using VDI snapshot files (TODO).
* VDI snapshot files may also contain the complete machine state.
* Maybe this machine state can be converted to QEMU PC machine snapshot data.
*
* The driver keeps a block cache (little endian entries) in memory.
* For the standard block size (1 MiB), a 1 TiB disk will use 4 MiB RAM,
* so this seems to be reasonable.
*/
#include "qemu-common.h"
#include "block/block_int.h"
#include "qemu/module.h"
#include "migration/migration.h"
#if defined(CONFIG_UUID)
#include <uuid/uuid.h>
#else
/* TODO: move uuid emulation to some central place in QEMU. */
#include "sysemu/sysemu.h" /* UUID_FMT */
typedef unsigned char uuid_t[16];
#endif
/* Code configuration options. */
/* Enable debug messages. */
//~ #define CONFIG_VDI_DEBUG
/* Support write operations on VDI images. */
#define CONFIG_VDI_WRITE
/* Support non-standard block (cluster) size. This is untested.
* Maybe it will be needed for very large images.
*/
//~ #define CONFIG_VDI_BLOCK_SIZE
/* Support static (fixed, pre-allocated) images. */
#define CONFIG_VDI_STATIC_IMAGE
/* Command line option for static images. */
#define BLOCK_OPT_STATIC "static"
#define KiB 1024
#define MiB (KiB * KiB)
#define SECTOR_SIZE 512
#define DEFAULT_CLUSTER_SIZE (1 * MiB)
#if defined(CONFIG_VDI_DEBUG)
#define logout(fmt, ...) \
fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__)
#else
#define logout(fmt, ...) ((void)0)
#endif
/* Image signature. */
#define VDI_SIGNATURE 0xbeda107f
/* Image version. */
#define VDI_VERSION_1_1 0x00010001
/* Image type. */
#define VDI_TYPE_DYNAMIC 1
#define VDI_TYPE_STATIC 2
/* Innotek / SUN images use these strings in header.text:
* "<<< innotek VirtualBox Disk Image >>>\n"
* "<<< Sun xVM VirtualBox Disk Image >>>\n"
* "<<< Sun VirtualBox Disk Image >>>\n"
* The value does not matter, so QEMU created images use a different text.
*/
#define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n"
/* A never-allocated block; semantically arbitrary content. */
#define VDI_UNALLOCATED 0xffffffffU
/* A discarded (no longer allocated) block; semantically zero-filled. */
#define VDI_DISCARDED 0xfffffffeU
#define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED)
/* The bmap will take up VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) bytes; since
* the bmap is read and written in a single operation, its size needs to be
* limited to INT_MAX; furthermore, when opening an image, the bmap size is
* rounded up to be aligned on BDRV_SECTOR_SIZE.
* Therefore this should satisfy the following:
* VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) + BDRV_SECTOR_SIZE == INT_MAX + 1
* (INT_MAX + 1 is the first value not representable as an int)
* This guarantees that any value below or equal to the constant will, when
* multiplied by sizeof(uint32_t) and rounded up to a BDRV_SECTOR_SIZE boundary,
* still be below or equal to INT_MAX. */
#define VDI_BLOCKS_IN_IMAGE_MAX \
((unsigned)((INT_MAX + 1u - BDRV_SECTOR_SIZE) / sizeof(uint32_t)))
#define VDI_DISK_SIZE_MAX ((uint64_t)VDI_BLOCKS_IN_IMAGE_MAX * \
(uint64_t)DEFAULT_CLUSTER_SIZE)
#if !defined(CONFIG_UUID)
static inline void uuid_generate(uuid_t out)
{
memset(out, 0, sizeof(uuid_t));
}
static inline int uuid_is_null(const uuid_t uu)
{
uuid_t null_uuid = { 0 };
return memcmp(uu, null_uuid, sizeof(uuid_t)) == 0;
}
# if defined(CONFIG_VDI_DEBUG)
static inline void uuid_unparse(const uuid_t uu, char *out)
{
snprintf(out, 37, UUID_FMT,
uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7],
uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]);
}
# endif
#endif
typedef struct {
char text[0x40];
uint32_t signature;
uint32_t version;
uint32_t header_size;
uint32_t image_type;
uint32_t image_flags;
char description[256];
uint32_t offset_bmap;
uint32_t offset_data;
uint32_t cylinders; /* disk geometry, unused here */
uint32_t heads; /* disk geometry, unused here */
uint32_t sectors; /* disk geometry, unused here */
uint32_t sector_size;
uint32_t unused1;
uint64_t disk_size;
uint32_t block_size;
uint32_t block_extra; /* unused here */
uint32_t blocks_in_image;
uint32_t blocks_allocated;
uuid_t uuid_image;
uuid_t uuid_last_snap;
uuid_t uuid_link;
uuid_t uuid_parent;
uint64_t unused2[7];
} QEMU_PACKED VdiHeader;
typedef struct {
/* The block map entries are little endian (even in memory). */
uint32_t *bmap;
/* Size of block (bytes). */
uint32_t block_size;
/* Size of block (sectors). */
uint32_t block_sectors;
/* First sector of block map. */
uint32_t bmap_sector;
/* VDI header (converted to host endianness). */
VdiHeader header;
Error *migration_blocker;
} BDRVVdiState;
/* Change UUID from little endian (IPRT = VirtualBox format) to big endian
* format (network byte order, standard, see RFC 4122) and vice versa.
*/
static void uuid_convert(uuid_t uuid)
{
bswap32s((uint32_t *)&uuid[0]);
bswap16s((uint16_t *)&uuid[4]);
bswap16s((uint16_t *)&uuid[6]);
}
static void vdi_header_to_cpu(VdiHeader *header)
{
le32_to_cpus(&header->signature);
le32_to_cpus(&header->version);
le32_to_cpus(&header->header_size);
le32_to_cpus(&header->image_type);
le32_to_cpus(&header->image_flags);
le32_to_cpus(&header->offset_bmap);
le32_to_cpus(&header->offset_data);
le32_to_cpus(&header->cylinders);
le32_to_cpus(&header->heads);
le32_to_cpus(&header->sectors);
le32_to_cpus(&header->sector_size);
le64_to_cpus(&header->disk_size);
le32_to_cpus(&header->block_size);
le32_to_cpus(&header->block_extra);
le32_to_cpus(&header->blocks_in_image);
le32_to_cpus(&header->blocks_allocated);
uuid_convert(header->uuid_image);
uuid_convert(header->uuid_last_snap);
uuid_convert(header->uuid_link);
uuid_convert(header->uuid_parent);
}
static void vdi_header_to_le(VdiHeader *header)
{
cpu_to_le32s(&header->signature);
cpu_to_le32s(&header->version);
cpu_to_le32s(&header->header_size);
cpu_to_le32s(&header->image_type);
cpu_to_le32s(&header->image_flags);
cpu_to_le32s(&header->offset_bmap);
cpu_to_le32s(&header->offset_data);
cpu_to_le32s(&header->cylinders);
cpu_to_le32s(&header->heads);
cpu_to_le32s(&header->sectors);
cpu_to_le32s(&header->sector_size);
cpu_to_le64s(&header->disk_size);
cpu_to_le32s(&header->block_size);
cpu_to_le32s(&header->block_extra);
cpu_to_le32s(&header->blocks_in_image);
cpu_to_le32s(&header->blocks_allocated);
uuid_convert(header->uuid_image);
uuid_convert(header->uuid_last_snap);
uuid_convert(header->uuid_link);
uuid_convert(header->uuid_parent);
}
#if defined(CONFIG_VDI_DEBUG)
static void vdi_header_print(VdiHeader *header)
{
char uuid[37];
logout("text %s", header->text);
logout("signature 0x%08x\n", header->signature);
logout("header size 0x%04x\n", header->header_size);
logout("image type 0x%04x\n", header->image_type);
logout("image flags 0x%04x\n", header->image_flags);
logout("description %s\n", header->description);
logout("offset bmap 0x%04x\n", header->offset_bmap);
logout("offset data 0x%04x\n", header->offset_data);
logout("cylinders 0x%04x\n", header->cylinders);
logout("heads 0x%04x\n", header->heads);
logout("sectors 0x%04x\n", header->sectors);
logout("sector size 0x%04x\n", header->sector_size);
logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n",
header->disk_size, header->disk_size / MiB);
logout("block size 0x%04x\n", header->block_size);
logout("block extra 0x%04x\n", header->block_extra);
logout("blocks tot. 0x%04x\n", header->blocks_in_image);
logout("blocks all. 0x%04x\n", header->blocks_allocated);
uuid_unparse(header->uuid_image, uuid);
logout("uuid image %s\n", uuid);
uuid_unparse(header->uuid_last_snap, uuid);
logout("uuid snap %s\n", uuid);
uuid_unparse(header->uuid_link, uuid);
logout("uuid link %s\n", uuid);
uuid_unparse(header->uuid_parent, uuid);
logout("uuid parent %s\n", uuid);
}
#endif
static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
/* TODO: additional checks possible. */
BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
uint32_t blocks_allocated = 0;
uint32_t block;
uint32_t *bmap;
logout("\n");
if (fix) {
return -ENOTSUP;
}
bmap = g_try_new(uint32_t, s->header.blocks_in_image);
if (s->header.blocks_in_image && bmap == NULL) {
res->check_errors++;
return -ENOMEM;
}
memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t));
/* Check block map and value of blocks_allocated. */
for (block = 0; block < s->header.blocks_in_image; block++) {
uint32_t bmap_entry = le32_to_cpu(s->bmap[block]);
if (VDI_IS_ALLOCATED(bmap_entry)) {
if (bmap_entry < s->header.blocks_in_image) {
blocks_allocated++;
if (!VDI_IS_ALLOCATED(bmap[bmap_entry])) {
bmap[bmap_entry] = bmap_entry;
} else {
fprintf(stderr, "ERROR: block index %" PRIu32
" also used by %" PRIu32 "\n", bmap[bmap_entry], bmap_entry);
res->corruptions++;
}
} else {
fprintf(stderr, "ERROR: block index %" PRIu32
" too large, is %" PRIu32 "\n", block, bmap_entry);
res->corruptions++;
}
}
}
if (blocks_allocated != s->header.blocks_allocated) {
fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32
", should be %" PRIu32 "\n",
blocks_allocated, s->header.blocks_allocated);
res->corruptions++;
}
g_free(bmap);
return 0;
}
static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
/* TODO: vdi_get_info would be needed for machine snapshots.
vm_state_offset is still missing. */
BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
logout("\n");
bdi->cluster_size = s->block_size;
bdi->vm_state_offset = 0;
bdi->unallocated_blocks_are_zero = true;
return 0;
}
static int vdi_make_empty(BlockDriverState *bs)
{
/* TODO: missing code. */
logout("\n");
/* The return value for missing code must be 0, see block.c. */
return 0;
}
static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename)
{
const VdiHeader *header = (const VdiHeader *)buf;
int ret = 0;
logout("\n");
if (buf_size < sizeof(*header)) {
/* Header too small, no VDI. */
} else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) {
ret = 100;
}
if (ret == 0) {
logout("no vdi image\n");
} else {
logout("%s", header->text);
}
return ret;
}
static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVVdiState *s = bs->opaque;
VdiHeader header;
size_t bmap_size;
int ret;
logout("\n");
ret = bdrv_read(bs->file, 0, (uint8_t *)&header, 1);
if (ret < 0) {
goto fail;
}
vdi_header_to_cpu(&header);
#if defined(CONFIG_VDI_DEBUG)
vdi_header_print(&header);
#endif
if (header.disk_size > VDI_DISK_SIZE_MAX) {
error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64
", max supported is 0x%" PRIx64 ")",
header.disk_size, VDI_DISK_SIZE_MAX);
ret = -ENOTSUP;
goto fail;
}
if (header.disk_size % SECTOR_SIZE != 0) {
/* 'VBoxManage convertfromraw' can create images with odd disk sizes.
We accept them but round the disk size to the next multiple of
SECTOR_SIZE. */
logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size);
header.disk_size = ROUND_UP(header.disk_size, SECTOR_SIZE);
}
if (header.signature != VDI_SIGNATURE) {
error_setg(errp, "Image not in VDI format (bad signature %08" PRIx32
")", header.signature);
ret = -EINVAL;
goto fail;
} else if (header.version != VDI_VERSION_1_1) {
error_setg(errp, "unsupported VDI image (version %" PRIu32 ".%" PRIu32
")", header.version >> 16, header.version & 0xffff);
ret = -ENOTSUP;
goto fail;
} else if (header.offset_bmap % SECTOR_SIZE != 0) {
/* We only support block maps which start on a sector boundary. */
error_setg(errp, "unsupported VDI image (unaligned block map offset "
"0x%" PRIx32 ")", header.offset_bmap);
ret = -ENOTSUP;
goto fail;
} else if (header.offset_data % SECTOR_SIZE != 0) {
/* We only support data blocks which start on a sector boundary. */
error_setg(errp, "unsupported VDI image (unaligned data offset 0x%"
PRIx32 ")", header.offset_data);
ret = -ENOTSUP;
goto fail;
} else if (header.sector_size != SECTOR_SIZE) {
error_setg(errp, "unsupported VDI image (sector size %" PRIu32
" is not %u)", header.sector_size, SECTOR_SIZE);
ret = -ENOTSUP;
goto fail;
} else if (header.block_size != DEFAULT_CLUSTER_SIZE) {
error_setg(errp, "unsupported VDI image (block size %" PRIu32
" is not %u)", header.block_size, DEFAULT_CLUSTER_SIZE);
ret = -ENOTSUP;
goto fail;
} else if (header.disk_size >
(uint64_t)header.blocks_in_image * header.block_size) {
error_setg(errp, "unsupported VDI image (disk size %" PRIu64 ", "
"image bitmap has room for %" PRIu64 ")",
header.disk_size,
(uint64_t)header.blocks_in_image * header.block_size);
ret = -ENOTSUP;
goto fail;
} else if (!uuid_is_null(header.uuid_link)) {
error_setg(errp, "unsupported VDI image (non-NULL link UUID)");
ret = -ENOTSUP;
goto fail;
} else if (!uuid_is_null(header.uuid_parent)) {
error_setg(errp, "unsupported VDI image (non-NULL parent UUID)");
ret = -ENOTSUP;
goto fail;
} else if (header.blocks_in_image > VDI_BLOCKS_IN_IMAGE_MAX) {
error_setg(errp, "unsupported VDI image "
"(too many blocks %u, max is %u)",
header.blocks_in_image, VDI_BLOCKS_IN_IMAGE_MAX);
ret = -ENOTSUP;
goto fail;
}
bs->total_sectors = header.disk_size / SECTOR_SIZE;
s->block_size = header.block_size;
s->block_sectors = header.block_size / SECTOR_SIZE;
s->bmap_sector = header.offset_bmap / SECTOR_SIZE;
s->header = header;
bmap_size = header.blocks_in_image * sizeof(uint32_t);
bmap_size = DIV_ROUND_UP(bmap_size, SECTOR_SIZE);
s->bmap = qemu_try_blockalign(bs->file, bmap_size * SECTOR_SIZE);
if (s->bmap == NULL) {
ret = -ENOMEM;
goto fail;
}
ret = bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size);
if (ret < 0) {
goto fail_free_bmap;
}
/* Disable migration when vdi images are used */
error_set(&s->migration_blocker,
QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
"vdi", bdrv_get_device_name(bs), "live migration");
migrate_add_blocker(s->migration_blocker);
return 0;
fail_free_bmap:
qemu_vfree(s->bmap);
fail:
return ret;
}
static int vdi_reopen_prepare(BDRVReopenState *state,
BlockReopenQueue *queue, Error **errp)
{
return 0;
}
static int64_t coroutine_fn vdi_co_get_block_status(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum)
{
/* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */
BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
size_t bmap_index = sector_num / s->block_sectors;
size_t sector_in_block = sector_num % s->block_sectors;
int n_sectors = s->block_sectors - sector_in_block;
uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]);
uint64_t offset;
int result;
logout("%p, %" PRId64 ", %d, %p\n", bs, sector_num, nb_sectors, pnum);
if (n_sectors > nb_sectors) {
n_sectors = nb_sectors;
}
*pnum = n_sectors;
result = VDI_IS_ALLOCATED(bmap_entry);
if (!result) {
return 0;
}
offset = s->header.offset_data +
(uint64_t)bmap_entry * s->block_size +
sector_in_block * SECTOR_SIZE;
return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset;
}
static int vdi_co_read(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors)
{
BDRVVdiState *s = bs->opaque;
uint32_t bmap_entry;
uint32_t block_index;
uint32_t sector_in_block;
uint32_t n_sectors;
int ret = 0;
logout("\n");
while (ret >= 0 && nb_sectors > 0) {
block_index = sector_num / s->block_sectors;
sector_in_block = sector_num % s->block_sectors;
n_sectors = s->block_sectors - sector_in_block;
if (n_sectors > nb_sectors) {
n_sectors = nb_sectors;
}
logout("will read %u sectors starting at sector %" PRIu64 "\n",
n_sectors, sector_num);
/* prepare next AIO request */
bmap_entry = le32_to_cpu(s->bmap[block_index]);
if (!VDI_IS_ALLOCATED(bmap_entry)) {
/* Block not allocated, return zeros, no need to wait. */
memset(buf, 0, n_sectors * SECTOR_SIZE);
ret = 0;
} else {
uint64_t offset = s->header.offset_data / SECTOR_SIZE +
(uint64_t)bmap_entry * s->block_sectors +
sector_in_block;
ret = bdrv_read(bs->file, offset, buf, n_sectors);
}
logout("%u sectors read\n", n_sectors);
nb_sectors -= n_sectors;
sector_num += n_sectors;
buf += n_sectors * SECTOR_SIZE;
}
return ret;
}
static int vdi_co_write(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors)
{
BDRVVdiState *s = bs->opaque;
uint32_t bmap_entry;
uint32_t block_index;
uint32_t sector_in_block;
uint32_t n_sectors;
uint32_t bmap_first = VDI_UNALLOCATED;
uint32_t bmap_last = VDI_UNALLOCATED;
uint8_t *block = NULL;
int ret = 0;
logout("\n");
while (ret >= 0 && nb_sectors > 0) {
block_index = sector_num / s->block_sectors;
sector_in_block = sector_num % s->block_sectors;
n_sectors = s->block_sectors - sector_in_block;
if (n_sectors > nb_sectors) {
n_sectors = nb_sectors;
}
logout("will write %u sectors starting at sector %" PRIu64 "\n",
n_sectors, sector_num);
/* prepare next AIO request */
bmap_entry = le32_to_cpu(s->bmap[block_index]);
if (!VDI_IS_ALLOCATED(bmap_entry)) {
/* Allocate new block and write to it. */
uint64_t offset;
bmap_entry = s->header.blocks_allocated;
s->bmap[block_index] = cpu_to_le32(bmap_entry);
s->header.blocks_allocated++;
offset = s->header.offset_data / SECTOR_SIZE +
(uint64_t)bmap_entry * s->block_sectors;
if (block == NULL) {
block = g_malloc(s->block_size);
bmap_first = block_index;
}
bmap_last = block_index;
/* Copy data to be written to new block and zero unused parts. */
memset(block, 0, sector_in_block * SECTOR_SIZE);
memcpy(block + sector_in_block * SECTOR_SIZE,
buf, n_sectors * SECTOR_SIZE);
memset(block + (sector_in_block + n_sectors) * SECTOR_SIZE, 0,
(s->block_sectors - n_sectors - sector_in_block) * SECTOR_SIZE);
ret = bdrv_write(bs->file, offset, block, s->block_sectors);
} else {
uint64_t offset = s->header.offset_data / SECTOR_SIZE +
(uint64_t)bmap_entry * s->block_sectors +
sector_in_block;
ret = bdrv_write(bs->file, offset, buf, n_sectors);
}
nb_sectors -= n_sectors;
sector_num += n_sectors;
buf += n_sectors * SECTOR_SIZE;
logout("%u sectors written\n", n_sectors);
}
logout("finished data write\n");
if (ret < 0) {
return ret;
}
if (block) {
/* One or more new blocks were allocated. */
VdiHeader *header = (VdiHeader *) block;
uint8_t *base;
uint64_t offset;
logout("now writing modified header\n");
assert(VDI_IS_ALLOCATED(bmap_first));
*header = s->header;
vdi_header_to_le(header);
ret = bdrv_write(bs->file, 0, block, 1);
g_free(block);
block = NULL;
if (ret < 0) {
return ret;
}
logout("now writing modified block map entry %u...%u\n",
bmap_first, bmap_last);
/* Write modified sectors from block map. */
bmap_first /= (SECTOR_SIZE / sizeof(uint32_t));
bmap_last /= (SECTOR_SIZE / sizeof(uint32_t));
n_sectors = bmap_last - bmap_first + 1;
offset = s->bmap_sector + bmap_first;
base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE;
logout("will write %u block map sectors starting from entry %u\n",
n_sectors, bmap_first);
ret = bdrv_write(bs->file, offset, base, n_sectors);
}
return ret;
}
static int vdi_create(const char *filename, QemuOpts *opts, Error **errp)
{
int ret = 0;
uint64_t bytes = 0;
uint32_t blocks;
size_t block_size = DEFAULT_CLUSTER_SIZE;
uint32_t image_type = VDI_TYPE_DYNAMIC;
VdiHeader header;
size_t i;
size_t bmap_size;
int64_t offset = 0;
Error *local_err = NULL;
BlockDriverState *bs = NULL;
uint32_t *bmap = NULL;
logout("\n");
/* Read out options. */
bytes = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
BDRV_SECTOR_SIZE);
#if defined(CONFIG_VDI_BLOCK_SIZE)
/* TODO: Additional checks (SECTOR_SIZE * 2^n, ...). */
block_size = qemu_opt_get_size_del(opts,
BLOCK_OPT_CLUSTER_SIZE,
DEFAULT_CLUSTER_SIZE);
#endif
#if defined(CONFIG_VDI_STATIC_IMAGE)
if (qemu_opt_get_bool_del(opts, BLOCK_OPT_STATIC, false)) {
image_type = VDI_TYPE_STATIC;
}
#endif
if (bytes > VDI_DISK_SIZE_MAX) {
ret = -ENOTSUP;
error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64
", max supported is 0x%" PRIx64 ")",
bytes, VDI_DISK_SIZE_MAX);
goto exit;
}
ret = bdrv_create_file(filename, opts, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto exit;
}
ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
NULL, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto exit;
}
/* We need enough blocks to store the given disk size,
so always round up. */
blocks = DIV_ROUND_UP(bytes, block_size);
bmap_size = blocks * sizeof(uint32_t);
bmap_size = ROUND_UP(bmap_size, SECTOR_SIZE);
memset(&header, 0, sizeof(header));
pstrcpy(header.text, sizeof(header.text), VDI_TEXT);
header.signature = VDI_SIGNATURE;
header.version = VDI_VERSION_1_1;
header.header_size = 0x180;
header.image_type = image_type;
header.offset_bmap = 0x200;
header.offset_data = 0x200 + bmap_size;
header.sector_size = SECTOR_SIZE;
header.disk_size = bytes;
header.block_size = block_size;
header.blocks_in_image = blocks;
if (image_type == VDI_TYPE_STATIC) {
header.blocks_allocated = blocks;
}
uuid_generate(header.uuid_image);
uuid_generate(header.uuid_last_snap);
/* There is no need to set header.uuid_link or header.uuid_parent here. */
#if defined(CONFIG_VDI_DEBUG)
vdi_header_print(&header);
#endif
vdi_header_to_le(&header);
ret = bdrv_pwrite_sync(bs, offset, &header, sizeof(header));
if (ret < 0) {
error_setg(errp, "Error writing header to %s", filename);
goto exit;
}
offset += sizeof(header);
if (bmap_size > 0) {
bmap = g_try_malloc0(bmap_size);
if (bmap == NULL) {
ret = -ENOMEM;
error_setg(errp, "Could not allocate bmap");
goto exit;
}
for (i = 0; i < blocks; i++) {
if (image_type == VDI_TYPE_STATIC) {
bmap[i] = i;
} else {
bmap[i] = VDI_UNALLOCATED;
}
}
ret = bdrv_pwrite_sync(bs, offset, bmap, bmap_size);
if (ret < 0) {
error_setg(errp, "Error writing bmap to %s", filename);
goto exit;
}
offset += bmap_size;
}
if (image_type == VDI_TYPE_STATIC) {
ret = bdrv_truncate(bs, offset + blocks * block_size);
if (ret < 0) {
error_setg(errp, "Failed to statically allocate %s", filename);
goto exit;
}
}
exit:
bdrv_unref(bs);
g_free(bmap);
return ret;
}
static void vdi_close(BlockDriverState *bs)
{
BDRVVdiState *s = bs->opaque;
qemu_vfree(s->bmap);
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
}
static QemuOptsList vdi_create_opts = {
.name = "vdi-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(vdi_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size"
},
#if defined(CONFIG_VDI_BLOCK_SIZE)
{
.name = BLOCK_OPT_CLUSTER_SIZE,
.type = QEMU_OPT_SIZE,
.help = "VDI cluster (block) size",
.def_value_str = stringify(DEFAULT_CLUSTER_SIZE)
},
#endif
#if defined(CONFIG_VDI_STATIC_IMAGE)
{
.name = BLOCK_OPT_STATIC,
.type = QEMU_OPT_BOOL,
.help = "VDI static (pre-allocated) image",
.def_value_str = "off"
},
#endif
{
.name = BLOCK_OPT_NOCOW,
.type = QEMU_OPT_BOOL,
.help = "Turn off copy-on-write (valid only on btrfs)"
},
/* TODO: An additional option to set UUID values might be useful. */
{ /* end of list */ }
}
};
static BlockDriver bdrv_vdi = {
.format_name = "vdi",
.instance_size = sizeof(BDRVVdiState),
.bdrv_probe = vdi_probe,
.bdrv_open = vdi_open,
.bdrv_close = vdi_close,
.bdrv_reopen_prepare = vdi_reopen_prepare,
.bdrv_create = vdi_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_get_block_status = vdi_co_get_block_status,
.bdrv_make_empty = vdi_make_empty,
.bdrv_read = vdi_co_read,
#if defined(CONFIG_VDI_WRITE)
.bdrv_write = vdi_co_write,
#endif
.bdrv_get_info = vdi_get_info,
.create_opts = &vdi_create_opts,
.bdrv_check = vdi_check,
};
static void bdrv_vdi_init(void)
{
logout("\n");
bdrv_register(&bdrv_vdi);
}
block_init(bdrv_vdi_init);
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