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e8b6535533
qemu/block/parallels.c
Stefan Hajnoczi e8b6535533 block: add BDRV_REQ_REGISTERED_BUF request flag 
Block drivers may optimize I/O requests accessing buffers previously
registered with bdrv_register_buf(). Checking whether all elements of a
request's QEMUIOVector are within previously registered buffers is
expensive, so we need a hint from the user to avoid costly checks.

Add a BDRV_REQ_REGISTERED_BUF request flag to indicate that all
QEMUIOVector elements in an I/O request are known to be within
previously registered buffers.

Always pass the flag through to driver read/write functions. There is
little harm in passing the flag to a driver that does not use it.
Passing the flag to drivers avoids changes across many block drivers.
Filter drivers would need to explicitly support the flag and pass
through to their children when the children support it. That's a lot of
code changes and it's hard to remember to do that everywhere, leading to
silent reduced performance when the flag is accidentally dropped.

The only problematic scenario with the approach in this patch is when a
driver passes the flag through to internal I/O requests that don't use
the same I/O buffer. In that case the hint may be set when it should
actually be clear. This is a rare case though so the risk is low.

Some drivers have assert(!flags), which no longer works when
BDRV_REQ_REGISTERED_BUF is passed in. These assertions aren't very
useful anyway since the functions are called almost exclusively by
bdrv_driver_preadv/pwritev() so if we get flags handling right there
then the assertion is not needed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-26 14:56:42 -04:00

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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 "qemu/error-report.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 "qemu/memalign.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 coroutine_fn 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_pwrite(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, to_write, (uint8_t *)s->header + off,
0);
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;
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;
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 + s->cluster_size) != off) {
res->bfi.fragmented_clusters++;
}
prev_off = off;
}
ret = 0;
if (flush_bat) {
ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, s->header, 0);
if (ret < 0) {
res->check_errors++;
goto out;
}
}
res->image_end_offset = high_off + s->cluster_size;
if (size > res->image_end_offset) {
int64_t count;
count = DIV_ROUND_UP(size - res->image_end_offset, s->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, BDRV_SECTOR_SIZE, tmp, 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;
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, errp);
if (ret < 0) {
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, errp);
visit_free(v);
if (!create_options) {
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, size, s->header, 0);
}
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_of_bds,
BDRV_CHILD_IMAGE, false, errp);
if (!bs->file) {
return -EINVAL;
}
ret = bdrv_pread(bs->file, 0, sizeof(ph), &ph, 0);
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->cluster_size = s->tracks << BDRV_SECTOR_BITS;
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_size, s->header, 0);
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, errp);
if (!opts) {
goto fail_options;
}
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
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) {
error_propagate(errp, local_err);
goto fail_options;
}
if (ph.ext_off) {
if (flags & BDRV_O_RDWR) {
/*
* It's unsafe to open image RW if there is an extension (as we
* don't support it). But parallels driver in QEMU historically
* ignores the extension, so print warning and don't care.
*/
warn_report("Format Extension ignored in RW mode");
} else {
ret = parallels_read_format_extension(
bs, le64_to_cpu(ph.ext_off) << BDRV_SECTOR_BITS, errp);
if (ret < 0) {
goto fail;
}
}
}
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_activate 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, errp);
if (ret < 0) {
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");
fail_options:
ret = -EINVAL;
fail:
qemu_vfree(s->header);
return ret;
}
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_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,
.is_format = true,
.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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