qemu/block/parallels.c
Denis V. Lunev dd97cdc064 block/parallels: keep BAT bitmap data in little endian in memory
This will allow to use this data as buffer to BAT update directly
without any intermediate buffers.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@parallels.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Roman Kagan <rkagan@parallels.com>
Message-id: 1430207220-24458-17-git-send-email-den@openvz.org
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-05-22 09:37:32 +01:00

446 lines
12 KiB
C

/*
* Block driver for Parallels disk image format
*
* Copyright (c) 2007 Alex Beregszaszi
* Copyright (c) 2015 Denis V. Lunev <den@openvz.org>
*
* This code was originally based on comparing different disk images created
* by Parallels. Currently it is based on opened OpenVZ sources
* available at
* http://git.openvz.org/?p=ploop;a=summary
*
* 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/block_int.h"
#include "qemu/module.h"
/**************************************************************/
#define HEADER_MAGIC "WithoutFreeSpace"
#define HEADER_MAGIC2 "WithouFreSpacExt"
#define HEADER_VERSION 2
#define DEFAULT_CLUSTER_SIZE 1048576 /* 1 MiB */
// always little-endian
typedef struct ParallelsHeader {
char magic[16]; // "WithoutFreeSpace"
uint32_t version;
uint32_t heads;
uint32_t cylinders;
uint32_t tracks;
uint32_t bat_entries;
uint64_t nb_sectors;
uint32_t inuse;
uint32_t data_off;
char padding[12];
} QEMU_PACKED ParallelsHeader;
typedef struct BDRVParallelsState {
/** Locking is conservative, the lock protects
* - image file extending (truncate, fallocate)
* - any access to block allocation table
*/
CoMutex lock;
uint32_t *bat_bitmap;
unsigned int bat_size;
unsigned int tracks;
unsigned int off_multiplier;
bool has_truncate;
} BDRVParallelsState;
static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
{
const ParallelsHeader *ph = (const void *)buf;
if (buf_size < sizeof(ParallelsHeader))
return 0;
if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
!memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
(le32_to_cpu(ph->version) == HEADER_VERSION))
return 100;
return 0;
}
static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVParallelsState *s = bs->opaque;
ParallelsHeader ph;
int ret;
ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
if (ret < 0) {
goto fail;
}
bs->total_sectors = le64_to_cpu(ph.nb_sectors);
if (le32_to_cpu(ph.version) != HEADER_VERSION) {
goto fail_format;
}
if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
s->off_multiplier = 1;
bs->total_sectors = 0xffffffff & bs->total_sectors;
} else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
s->off_multiplier = le32_to_cpu(ph.tracks);
} else {
goto fail_format;
}
s->tracks = le32_to_cpu(ph.tracks);
if (s->tracks == 0) {
error_setg(errp, "Invalid image: Zero sectors per track");
ret = -EINVAL;
goto fail;
}
if (s->tracks > INT32_MAX/513) {
error_setg(errp, "Invalid image: Too big cluster");
ret = -EFBIG;
goto fail;
}
s->bat_size = le32_to_cpu(ph.bat_entries);
if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
error_setg(errp, "Catalog too large");
ret = -EFBIG;
goto fail;
}
s->bat_bitmap = g_try_new(uint32_t, s->bat_size);
if (s->bat_size && s->bat_bitmap == NULL) {
ret = -ENOMEM;
goto fail;
}
ret = bdrv_pread(bs->file, sizeof(ParallelsHeader),
s->bat_bitmap, s->bat_size * sizeof(uint32_t));
if (ret < 0) {
goto fail;
}
s->has_truncate = bdrv_has_zero_init(bs->file) &&
bdrv_truncate(bs->file, bdrv_getlength(bs->file)) == 0;
qemu_co_mutex_init(&s->lock);
return 0;
fail_format:
error_setg(errp, "Image not in Parallels format");
ret = -EINVAL;
fail:
g_free(s->bat_bitmap);
return ret;
}
static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
{
return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
}
static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
{
uint32_t index, offset;
index = sector_num / s->tracks;
offset = sector_num % s->tracks;
/* not allocated */
if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
return -1;
}
return bat2sect(s, index) + offset;
}
static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
int nb_sectors)
{
int ret = s->tracks - sector_num % s->tracks;
return MIN(nb_sectors, ret);
}
static int64_t allocate_cluster(BlockDriverState *bs, int64_t sector_num)
{
BDRVParallelsState *s = bs->opaque;
uint32_t idx, offset;
int64_t pos;
int ret;
idx = sector_num / s->tracks;
offset = sector_num % s->tracks;
if (idx >= s->bat_size) {
return -EINVAL;
}
if (s->bat_bitmap[idx] != 0) {
return bat2sect(s, idx) + offset;
}
pos = bdrv_getlength(bs->file) >> BDRV_SECTOR_BITS;
if (s->has_truncate) {
ret = bdrv_truncate(bs->file, (pos + s->tracks) << BDRV_SECTOR_BITS);
} else {
ret = bdrv_write_zeroes(bs->file, pos, s->tracks, 0);
}
if (ret < 0) {
return ret;
}
s->bat_bitmap[idx] = cpu_to_le32(pos / s->off_multiplier);
ret = bdrv_pwrite(bs->file,
sizeof(ParallelsHeader) + idx * sizeof(s->bat_bitmap[idx]),
s->bat_bitmap + idx, sizeof(s->bat_bitmap[idx]));
if (ret < 0) {
s->bat_bitmap[idx] = 0;
return ret;
}
return bat2sect(s, idx) + offset;
}
static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum)
{
BDRVParallelsState *s = bs->opaque;
int64_t offset;
qemu_co_mutex_lock(&s->lock);
offset = seek_to_sector(s, sector_num);
qemu_co_mutex_unlock(&s->lock);
*pnum = cluster_remainder(s, sector_num, nb_sectors);
if (offset < 0) {
return 0;
}
return (offset << BDRV_SECTOR_BITS) |
BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
BDRVParallelsState *s = bs->opaque;
uint64_t bytes_done = 0;
QEMUIOVector hd_qiov;
int ret = 0;
qemu_iovec_init(&hd_qiov, qiov->niov);
while (nb_sectors > 0) {
int64_t position;
int n, nbytes;
qemu_co_mutex_lock(&s->lock);
position = allocate_cluster(bs, sector_num);
qemu_co_mutex_unlock(&s->lock);
if (position < 0) {
ret = (int)position;
break;
}
n = cluster_remainder(s, sector_num, nb_sectors);
nbytes = n << BDRV_SECTOR_BITS;
qemu_iovec_reset(&hd_qiov);
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
if (ret < 0) {
break;
}
nb_sectors -= n;
sector_num += n;
bytes_done += nbytes;
}
qemu_iovec_destroy(&hd_qiov);
return ret;
}
static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
BDRVParallelsState *s = bs->opaque;
uint64_t bytes_done = 0;
QEMUIOVector hd_qiov;
int ret = 0;
qemu_iovec_init(&hd_qiov, qiov->niov);
while (nb_sectors > 0) {
int64_t position;
int n, nbytes;
qemu_co_mutex_lock(&s->lock);
position = seek_to_sector(s, sector_num);
qemu_co_mutex_unlock(&s->lock);
n = cluster_remainder(s, sector_num, nb_sectors);
nbytes = n << BDRV_SECTOR_BITS;
if (position < 0) {
qemu_iovec_memset(qiov, bytes_done, 0, nbytes);
} else {
qemu_iovec_reset(&hd_qiov);
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
ret = bdrv_co_readv(bs->file, position, n, &hd_qiov);
if (ret < 0) {
break;
}
}
nb_sectors -= n;
sector_num += n;
bytes_done += nbytes;
}
qemu_iovec_destroy(&hd_qiov);
return ret;
}
static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
{
int64_t total_size, cl_size;
uint8_t tmp[BDRV_SECTOR_SIZE];
Error *local_err = NULL;
BlockDriverState *file;
uint32_t bat_entries, bat_sectors;
ParallelsHeader header;
int ret;
total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
BDRV_SECTOR_SIZE);
cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
ret = bdrv_create_file(filename, opts, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
return ret;
}
file = NULL;
ret = bdrv_open(&file, filename, NULL, NULL,
BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
return ret;
}
ret = bdrv_truncate(file, 0);
if (ret < 0) {
goto exit;
}
bat_entries = DIV_ROUND_UP(total_size, cl_size);
bat_sectors = DIV_ROUND_UP(bat_entries * sizeof(uint32_t) +
sizeof(ParallelsHeader), cl_size);
bat_sectors = (bat_sectors * cl_size) >> BDRV_SECTOR_BITS;
memset(&header, 0, sizeof(header));
memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
header.version = cpu_to_le32(HEADER_VERSION);
/* don't care much about geometry, it is not used on image level */
header.heads = cpu_to_le32(16);
header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE / 16 / 32);
header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
header.bat_entries = cpu_to_le32(bat_entries);
header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
header.data_off = cpu_to_le32(bat_sectors);
/* write all the data */
memset(tmp, 0, sizeof(tmp));
memcpy(tmp, &header, sizeof(header));
ret = bdrv_pwrite(file, 0, tmp, BDRV_SECTOR_SIZE);
if (ret < 0) {
goto exit;
}
ret = bdrv_write_zeroes(file, 1, bat_sectors - 1, 0);
if (ret < 0) {
goto exit;
}
ret = 0;
done:
bdrv_unref(file);
return ret;
exit:
error_setg_errno(errp, -ret, "Failed to create Parallels image");
goto done;
}
static void parallels_close(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
g_free(s->bat_bitmap);
}
static QemuOptsList parallels_create_opts = {
.name = "parallels-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size",
},
{
.name = BLOCK_OPT_CLUSTER_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Parallels image cluster size",
.def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
},
{ /* end of list */ }
}
};
static BlockDriver bdrv_parallels = {
.format_name = "parallels",
.instance_size = sizeof(BDRVParallelsState),
.bdrv_probe = parallels_probe,
.bdrv_open = parallels_open,
.bdrv_close = parallels_close,
.bdrv_co_get_block_status = parallels_co_get_block_status,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_readv = parallels_co_readv,
.bdrv_co_writev = parallels_co_writev,
.bdrv_create = parallels_create,
.create_opts = &parallels_create_opts,
};
static void bdrv_parallels_init(void)
{
bdrv_register(&bdrv_parallels);
}
block_init(bdrv_parallels_init);