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bda4cdcbb9
xemu/block/parallels.c
Eric Blake bda4cdcbb9 parallels: Rework truncation logic 
The parallels driver tries to use truncation for image growth, but can
only do so when reads are guaranteed as zero.  Now that we have a way
to request zero contents from truncation, we can defer the decision to
actual allocation attempts rather than up front, reducing the number
of places that still use bdrv_has_zero_init_truncate.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-8-eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08 13:26:35 +02:00

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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/osdep.h"
#include "qapi/error.h"
#include "block/block_int.h"
#include "block/qdict.h"
#include "sysemu/block-backend.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qapi-visit-block-core.h"
#include "qemu/bswap.h"
#include "qemu/bitmap.h"
#include "migration/blocker.h"
#include "parallels.h"
/**************************************************************/
#define HEADER_MAGIC "WithoutFreeSpace"
#define HEADER_MAGIC2 "WithouFreSpacExt"
#define HEADER_VERSION 2
#define HEADER_INUSE_MAGIC (0x746F6E59)
#define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
static QEnumLookup prealloc_mode_lookup = {
.array = (const char *const[]) {
"falloc",
"truncate",
},
.size = PRL_PREALLOC_MODE__MAX
};
#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 = "128M",
},
{
.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 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 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)
{
int ret = 0;
BDRVParallelsState *s = bs->opaque;
int64_t pos, space, idx, to_allocate, i, len;
pos = block_status(s, sector_num, nb_sectors, pnum);
if (pos > 0) {
return pos;
}
idx = sector_num / s->tracks;
to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
/* This function is called only by parallels_co_writev(), which will never
* pass a sector_num at or beyond the end of the image (because the block
* layer never passes such a sector_num to that function). Therefore, idx
* is always below s->bat_size.
* block_status() will limit *pnum so that sector_num + *pnum will not
* exceed the image end. Therefore, idx + to_allocate cannot exceed
* s->bat_size.
* Note that s->bat_size is an unsigned int, therefore idx + to_allocate
* will always fit into a uint32_t. */
assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
space = to_allocate * s->tracks;
len = bdrv_getlength(bs->file->bs);
if (len < 0) {
return len;
}
if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
space += s->prealloc_size;
/*
* We require the expanded size to read back as zero. If the
* user permitted truncation, we try that; but if it fails, we
* force the safer-but-slower fallocate.
*/
if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
ret = bdrv_truncate(bs->file,
(s->data_end + space) << BDRV_SECTOR_BITS,
false, PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE,
NULL);
if (ret == -ENOTSUP) {
s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
}
}
if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
ret = bdrv_pwrite_zeroes(bs->file,
s->data_end << BDRV_SECTOR_BITS,
space << BDRV_SECTOR_BITS, 0);
}
if (ret < 0) {
return ret;
}
}
/* Try to read from backing to fill empty clusters
* FIXME: 1. previous write_zeroes may be redundant
* 2. most of data we read from backing will be rewritten by
* parallels_co_writev. On aligned-to-cluster write we do not need
* this read at all.
* 3. it would be good to combine write of data from backing and new
* data into one write call */
if (bs->backing) {
int64_t nb_cow_sectors = to_allocate * s->tracks;
int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
void *buf = qemu_blockalign(bs, nb_cow_bytes);
ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
nb_cow_bytes, buf, 0);
if (ret < 0) {
qemu_vfree(buf);
return ret;
}
ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
nb_cow_bytes, buf, 0);
qemu_vfree(buf);
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, 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 int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
bool want_zero,
int64_t offset,
int64_t bytes,
int64_t *pnum,
int64_t *map,
BlockDriverState **file)
{
BDRVParallelsState *s = bs->opaque;
int count;
assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
qemu_co_mutex_lock(&s->lock);
offset = block_status(s, offset >> BDRV_SECTOR_BITS,
bytes >> BDRV_SECTOR_BITS, &count);
qemu_co_mutex_unlock(&s->lock);
*pnum = count * BDRV_SECTOR_SIZE;
if (offset < 0) {
return 0;
}
*map = offset * BDRV_SECTOR_SIZE;
*file = bs->file->bs;
return 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, int flags)
{
BDRVParallelsState *s = bs->opaque;
uint64_t bytes_done = 0;
QEMUIOVector hd_qiov;
int ret = 0;
assert(!flags);
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_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
&hd_qiov, 0);
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;
qemu_iovec_reset(&hd_qiov);
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
if (position < 0) {
if (bs->backing) {
ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
nbytes, &hd_qiov, 0);
if (ret < 0) {
break;
}
} else {
qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
}
} else {
ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
&hd_qiov, 0);
if (ret < 0) {
break;
}
}
nb_sectors -= n;
sector_num += n;
bytes_done += nbytes;
}
qemu_iovec_destroy(&hd_qiov);
return ret;
}
static int coroutine_fn parallels_co_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;
}
qemu_co_mutex_lock(&s->lock);
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;
}
ret = 0;
if (flush_bat) {
ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
if (ret < 0) {
res->check_errors++;
goto out;
}
}
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) {
Error *local_err = NULL;
/*
* In order to really repair the image, we must shrink it.
* That means we have to pass exact=true.
*/
ret = bdrv_truncate(bs->file, res->image_end_offset, true,
PREALLOC_MODE_OFF, 0, &local_err);
if (ret < 0) {
error_report_err(local_err);
res->check_errors++;
goto out;
}
res->leaks_fixed += count;
}
}
out:
qemu_co_mutex_unlock(&s->lock);
return ret;
}
static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts,
Error **errp)
{
BlockdevCreateOptionsParallels *parallels_opts;
BlockDriverState *bs;
BlockBackend *blk;
int64_t total_size, cl_size;
uint32_t bat_entries, bat_sectors;
ParallelsHeader header;
uint8_t tmp[BDRV_SECTOR_SIZE];
int ret;
assert(opts->driver == BLOCKDEV_DRIVER_PARALLELS);
parallels_opts = &opts->u.parallels;
/* Sanity checks */
total_size = parallels_opts->size;
if (parallels_opts->has_cluster_size) {
cl_size = parallels_opts->cluster_size;
} else {
cl_size = DEFAULT_CLUSTER_SIZE;
}
/* XXX What is the real limit here? This is an insanely large maximum. */
if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
error_setg(errp, "Cluster size is too large");
return -EINVAL;
}
if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
error_setg(errp, "Image size is too large for this cluster size");
return -E2BIG;
}
if (!QEMU_IS_ALIGNED(total_size, BDRV_SECTOR_SIZE)) {
error_setg(errp, "Image size must be a multiple of 512 bytes");
return -EINVAL;
}
if (!QEMU_IS_ALIGNED(cl_size, BDRV_SECTOR_SIZE)) {
error_setg(errp, "Cluster size must be a multiple of 512 bytes");
return -EINVAL;
}
/* Create BlockBackend to write to the image */
bs = bdrv_open_blockdev_ref(parallels_opts->file, errp);
if (bs == NULL) {
return -EIO;
}
blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
errp);
if (!blk) {
ret = -EPERM;
goto out;
}
blk_set_allow_write_beyond_eof(blk, true);
/* Create image format */
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(HEADS_NUMBER);
header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
/ HEADS_NUMBER / SEC_IN_CYL);
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 = blk_pwrite(blk, 0, tmp, BDRV_SECTOR_SIZE, 0);
if (ret < 0) {
goto exit;
}
ret = blk_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
(bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
if (ret < 0) {
goto exit;
}
ret = 0;
out:
blk_unref(blk);
bdrv_unref(bs);
return ret;
exit:
error_setg_errno(errp, -ret, "Failed to create Parallels image");
goto out;
}
static int coroutine_fn parallels_co_create_opts(BlockDriver *drv,
const char *filename,
QemuOpts *opts,
Error **errp)
{
BlockdevCreateOptions *create_options = NULL;
Error *local_err = NULL;
BlockDriverState *bs = NULL;
QDict *qdict;
Visitor *v;
int ret;
static const QDictRenames opt_renames[] = {
{ BLOCK_OPT_CLUSTER_SIZE, "cluster-size" },
{ NULL, NULL },
};
/* Parse options and convert legacy syntax */
qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
true);
if (!qdict_rename_keys(qdict, opt_renames, errp)) {
ret = -EINVAL;
goto done;
}
/* Create and open the file (protocol layer) */
ret = bdrv_create_file(filename, opts, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto done;
}
bs = bdrv_open(filename, NULL, NULL,
BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
if (bs == NULL) {
ret = -EIO;
goto done;
}
/* Now get the QAPI type BlockdevCreateOptions */
qdict_put_str(qdict, "driver", "parallels");
qdict_put_str(qdict, "file", bs->node_name);
v = qobject_input_visitor_new_flat_confused(qdict, errp);
if (!v) {
ret = -EINVAL;
goto done;
}
visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
visit_free(v);
if (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto done;
}
/* Silently round up sizes */
create_options->u.parallels.size =
ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
create_options->u.parallels.cluster_size =
ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
/* Create the Parallels image (format layer) */
ret = parallels_co_create(create_options, errp);
if (ret < 0) {
goto done;
}
ret = 0;
done:
qobject_unref(qdict);
bdrv_unref(bs);
qapi_free_BlockdevCreateOptions(create_options);
return ret;
}
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, 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;
bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
false, errp);
if (!bs->file) {
return -EINVAL;
}
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;
}
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, 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);
/* prealloc_mode can be downgraded later during allocate_clusters */
s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
PRL_PREALLOC_MODE_FALLOCATE,
&local_err);
g_free(buf);
if (local_err != NULL) {
goto fail_options;
}
if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
ret = parallels_update_header(bs);
if (ret < 0) {
goto fail;
}
}
s->bat_dirty_block = 4 * qemu_real_host_page_size;
s->bat_dirty_bmap =
bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
/* Disable migration until bdrv_invalidate_cache method is added */
error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
"does not support live migration",
bdrv_get_device_or_node_name(bs));
ret = migrate_add_blocker(s->migration_blocker, &local_err);
if (local_err) {
error_propagate(errp, local_err);
error_free(s->migration_blocker);
goto fail;
}
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) && !(bs->open_flags & BDRV_O_INACTIVE)) {
s->header->inuse = 0;
parallels_update_header(bs);
/* errors are ignored, so we might as well pass exact=true */
bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, true,
PREALLOC_MODE_OFF, 0, NULL);
}
g_free(s->bat_dirty_bmap);
qemu_vfree(s->header);
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
}
static BlockDriver bdrv_parallels = {
.format_name = "parallels",
.instance_size = sizeof(BDRVParallelsState),
.bdrv_probe = parallels_probe,
.bdrv_open = parallels_open,
.bdrv_close = parallels_close,
.bdrv_child_perm = bdrv_format_default_perms,
.bdrv_co_block_status = parallels_co_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,
.supports_backing = true,
.bdrv_co_create = parallels_co_create,
.bdrv_co_create_opts = parallels_co_create_opts,
.bdrv_co_check = parallels_co_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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