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qemu/block/parallels.c

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/*
* 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"
#include "qemu/bitmap.h"
#include "qapi/util.h"
/**************************************************************/
#define HEADER_MAGIC "WithoutFreeSpace"
#define HEADER_MAGIC2 "WithouFreSpacExt"
#define HEADER_VERSION 2
#define HEADER_INUSE_MAGIC (0x746F6E59)
#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 enum ParallelsPreallocMode {
PRL_PREALLOC_MODE_FALLOCATE = 0,
PRL_PREALLOC_MODE_TRUNCATE = 1,
PRL_PREALLOC_MODE_MAX = 2,
} ParallelsPreallocMode;
static const char *prealloc_mode_lookup[] = {
"falloc",
"truncate",
NULL,
};
typedef struct BDRVParallelsState {
/** Locking is conservative, the lock protects
* - image file extending (truncate, fallocate)
* - any access to block allocation table
*/
CoMutex lock;
ParallelsHeader *header;
uint32_t header_size;
bool header_unclean;
unsigned long *bat_dirty_bmap;
unsigned int bat_dirty_block;
uint32_t *bat_bitmap;
unsigned int bat_size;
int64_t data_end;
uint64_t prealloc_size;
ParallelsPreallocMode prealloc_mode;
unsigned int tracks;
unsigned int off_multiplier;
} BDRVParallelsState;
#define PARALLELS_OPT_PREALLOC_MODE "prealloc-mode"
#define PARALLELS_OPT_PREALLOC_SIZE "prealloc-size"
static QemuOptsList parallels_runtime_opts = {
.name = "parallels",
.head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
.desc = {
{
.name = PARALLELS_OPT_PREALLOC_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Preallocation size on image expansion",
.def_value_str = "128MiB",
},
{
.name = PARALLELS_OPT_PREALLOC_MODE,
.type = QEMU_OPT_STRING,
.help = "Preallocation mode on image expansion "
"(allowed values: falloc, truncate)",
.def_value_str = "falloc",
},
{ /* end of list */ },
},
};
static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
{
return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
}
static uint32_t bat_entry_off(uint32_t idx)
{
return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
}
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 block_status(BDRVParallelsState *s, int64_t sector_num,
int nb_sectors, int *pnum)
{
int64_t start_off = -2, prev_end_off = -2;
*pnum = 0;
while (nb_sectors > 0 || start_off == -2) {
int64_t offset = seek_to_sector(s, sector_num);
int to_end;
if (start_off == -2) {
start_off = offset;
prev_end_off = offset;
} else if (offset != prev_end_off) {
break;
}
to_end = cluster_remainder(s, sector_num, nb_sectors);
nb_sectors -= to_end;
sector_num += to_end;
*pnum += to_end;
if (offset > 0) {
prev_end_off += to_end;
}
}
return start_off;
}
static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
BDRVParallelsState *s = bs->opaque;
uint32_t idx, to_allocate, i;
int64_t pos, space;
pos = block_status(s, sector_num, nb_sectors, pnum);
if (pos > 0) {
return pos;
}
idx = sector_num / s->tracks;
if (idx >= s->bat_size) {
return -EINVAL;
}
to_allocate = (sector_num + *pnum + s->tracks - 1) / s->tracks - idx;
space = to_allocate * s->tracks;
if (s->data_end + space > bdrv_getlength(bs->file->bs) >> BDRV_SECTOR_BITS) {
int ret;
space += s->prealloc_size;
if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
ret = bdrv_write_zeroes(bs->file->bs, s->data_end, space, 0);
} else {
ret = bdrv_truncate(bs->file->bs,
(s->data_end + space) << BDRV_SECTOR_BITS);
}
if (ret < 0) {
return ret;
}
}
for (i = 0; i < to_allocate; i++) {
s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
s->data_end += s->tracks;
bitmap_set(s->bat_dirty_bmap,
bat_entry_off(idx + i) / s->bat_dirty_block, 1);
}
return bat2sect(s, idx) + sector_num % s->tracks;
}
static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
unsigned long bit;
qemu_co_mutex_lock(&s->lock);
bit = find_first_bit(s->bat_dirty_bmap, size);
while (bit < size) {
uint32_t off = bit * s->bat_dirty_block;
uint32_t to_write = s->bat_dirty_block;
int ret;
if (off + to_write > s->header_size) {
to_write = s->header_size - off;
}
ret = bdrv_pwrite(bs->file->bs, off, (uint8_t *)s->header + off,
to_write);
if (ret < 0) {
qemu_co_mutex_unlock(&s->lock);
return ret;
}
bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
}
bitmap_zero(s->bat_dirty_bmap, size);
qemu_co_mutex_unlock(&s->lock);
return 0;
}
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 = block_status(s, sector_num, nb_sectors, pnum);
qemu_co_mutex_unlock(&s->lock);
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_clusters(bs, sector_num, nb_sectors, &n);
qemu_co_mutex_unlock(&s->lock);
if (position < 0) {
ret = (int)position;
break;
}
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->bs, 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 = block_status(s, sector_num, nb_sectors, &n);
qemu_co_mutex_unlock(&s->lock);
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->bs, 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_check(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
int64_t size, prev_off, high_off;
int ret;
uint32_t i;
bool flush_bat = false;
int cluster_size = s->tracks << BDRV_SECTOR_BITS;
size = bdrv_getlength(bs->file->bs);
if (size < 0) {
res->check_errors++;
return size;
}
if (s->header_unclean) {
fprintf(stderr, "%s image was not closed correctly\n",
fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
res->corruptions++;
if (fix & BDRV_FIX_ERRORS) {
/* parallels_close will do the job right */
res->corruptions_fixed++;
s->header_unclean = false;
}
}
res->bfi.total_clusters = s->bat_size;
res->bfi.compressed_clusters = 0; /* compression is not supported */
high_off = 0;
prev_off = 0;
for (i = 0; i < s->bat_size; i++) {
int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
if (off == 0) {
prev_off = 0;
continue;
}
/* cluster outside the image */
if (off > size) {
fprintf(stderr, "%s cluster %u is outside image\n",
fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
res->corruptions++;
if (fix & BDRV_FIX_ERRORS) {
prev_off = 0;
s->bat_bitmap[i] = 0;
res->corruptions_fixed++;
flush_bat = true;
continue;
}
}
res->bfi.allocated_clusters++;
if (off > high_off) {
high_off = off;
}
if (prev_off != 0 && (prev_off + cluster_size) != off) {
res->bfi.fragmented_clusters++;
}
prev_off = off;
}
if (flush_bat) {
ret = bdrv_pwrite_sync(bs->file->bs, 0, s->header, s->header_size);
if (ret < 0) {
res->check_errors++;
return ret;
}
}
res->image_end_offset = high_off + cluster_size;
if (size > res->image_end_offset) {
int64_t count;
count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
size - res->image_end_offset);
res->leaks += count;
if (fix & BDRV_FIX_LEAKS) {
ret = bdrv_truncate(bs->file->bs, res->image_end_offset);
if (ret < 0) {
res->check_errors++;
return ret;
}
res->leaks_fixed += count;
}
}
return 0;
}
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, &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_entry_off(bat_entries), 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 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_update_header(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
sizeof(ParallelsHeader));
if (size > s->header_size) {
size = s->header_size;
}
return bdrv_pwrite_sync(bs->file->bs, 0, s->header, size);
}
static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVParallelsState *s = bs->opaque;
ParallelsHeader ph;
int ret, size, i;
QemuOpts *opts = NULL;
Error *local_err = NULL;
char *buf;
ret = bdrv_pread(bs->file->bs, 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;
}
size = bat_entry_off(s->bat_size);
s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
if (s->header == NULL) {
ret = -ENOMEM;
goto fail;
}
s->data_end = le32_to_cpu(ph.data_off);
if (s->data_end == 0) {
s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
}
if (s->data_end < s->header_size) {
/* there is not enough unused space to fit to block align between BAT
and actual data. We can't avoid read-modify-write... */
s->header_size = size;
}
ret = bdrv_pread(bs->file->bs, 0, s->header, s->header_size);
if (ret < 0) {
goto fail;
}
s->bat_bitmap = (uint32_t *)(s->header + 1);
for (i = 0; i < s->bat_size; i++) {
int64_t off = bat2sect(s, i);
if (off >= s->data_end) {
s->data_end = off + s->tracks;
}
}
if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
/* Image was not closed correctly. The check is mandatory */
s->header_unclean = true;
if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
error_setg(errp, "parallels: Image was not closed correctly; "
"cannot be opened read/write");
ret = -EACCES;
goto fail;
}
}
opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
if (local_err != NULL) {
goto fail_options;
}
qemu_opts_absorb_qdict(opts, options, &local_err);
if (local_err != NULL) {
goto fail_options;
}
s->prealloc_size =
qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
s->prealloc_mode = qapi_enum_parse(prealloc_mode_lookup, buf,
PRL_PREALLOC_MODE_MAX, PRL_PREALLOC_MODE_FALLOCATE, &local_err);
g_free(buf);
if (local_err != NULL) {
goto fail_options;
}
if (!bdrv_has_zero_init(bs->file->bs) ||
bdrv_truncate(bs->file->bs, bdrv_getlength(bs->file->bs)) != 0) {
s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
}
if (flags & BDRV_O_RDWR) {
s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
ret = parallels_update_header(bs);
if (ret < 0) {
goto fail;
}
}
s->bat_dirty_block = 4 * getpagesize();
s->bat_dirty_bmap =
bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
qemu_co_mutex_init(&s->lock);
return 0;
fail_format:
error_setg(errp, "Image not in Parallels format");
ret = -EINVAL;
fail:
qemu_vfree(s->header);
return ret;
fail_options:
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
static void parallels_close(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
if (bs->open_flags & BDRV_O_RDWR) {
s->header->inuse = 0;
parallels_update_header(bs);
}
if (bs->open_flags & BDRV_O_RDWR) {
bdrv_truncate(bs->file->bs, s->data_end << BDRV_SECTOR_BITS);
}
g_free(s->bat_dirty_bmap);
qemu_vfree(s->header);
}
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_flush_to_os = parallels_co_flush_to_os,
.bdrv_co_readv = parallels_co_readv,
.bdrv_co_writev = parallels_co_writev,
.bdrv_create = parallels_create,
.bdrv_check = parallels_check,
.create_opts = &parallels_create_opts,
};
static void bdrv_parallels_init(void)
{
bdrv_register(&bdrv_parallels);
}
block_init(bdrv_parallels_init);
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