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qemu-e2k/block/parallels.c
Denis V. Lunev a98b260a52 parallels: naive implementation of parallels_co_pwrite_zeroes 
The zero flag is missed in the Parallels format specification. We can
resort to discard if we have no backing file.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
2023-09-21 08:49:17 +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 "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 uint32_t host_cluster_index(BDRVParallelsState *s, int64_t off)
{
off -= s->data_start << BDRV_SECTOR_BITS;
return off / s->cluster_size;
}
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 void parallels_set_bat_entry(BDRVParallelsState *s,
uint32_t index, uint32_t offset)
{
s->bat_bitmap[index] = cpu_to_le32(offset);
bitmap_set(s->bat_dirty_bmap, bat_entry_off(index) / s->bat_dirty_block, 1);
}
static int mark_used(BlockDriverState *bs, unsigned long *bitmap,
uint32_t bitmap_size, int64_t off, uint32_t count)
{
BDRVParallelsState *s = bs->opaque;
uint32_t cluster_index = host_cluster_index(s, off);
unsigned long next_used;
if (cluster_index + count > bitmap_size) {
return -E2BIG;
}
next_used = find_next_bit(bitmap, bitmap_size, cluster_index);
if (next_used < cluster_index + count) {
return -EBUSY;
}
bitmap_set(bitmap, cluster_index, count);
return 0;
}
/*
* Collect used bitmap. The image can contain errors, we should fill the
* bitmap anyway, as much as we can. This information will be used for
* error resolution.
*/
static int parallels_fill_used_bitmap(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
int64_t payload_bytes;
uint32_t i;
int err = 0;
payload_bytes = bdrv_getlength(bs->file->bs);
if (payload_bytes < 0) {
return payload_bytes;
}
payload_bytes -= s->data_start * BDRV_SECTOR_SIZE;
if (payload_bytes < 0) {
return -EINVAL;
}
s->used_bmap_size = DIV_ROUND_UP(payload_bytes, s->cluster_size);
if (s->used_bmap_size == 0) {
return 0;
}
s->used_bmap = bitmap_try_new(s->used_bmap_size);
if (s->used_bmap == NULL) {
return -ENOMEM;
}
for (i = 0; i < s->bat_size; i++) {
int err2;
int64_t host_off = bat2sect(s, i) << BDRV_SECTOR_BITS;
if (host_off == 0) {
continue;
}
err2 = mark_used(bs, s->used_bmap, s->used_bmap_size, host_off, 1);
if (err2 < 0 && err == 0) {
err = err2;
}
}
return err;
}
static void parallels_free_used_bitmap(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
s->used_bmap_size = 0;
g_free(s->used_bmap);
}
static int64_t coroutine_fn GRAPH_RDLOCK
allocate_clusters(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
int ret = 0;
BDRVParallelsState *s = bs->opaque;
int64_t i, pos, idx, to_allocate, first_free, host_off;
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);
first_free = find_first_zero_bit(s->used_bmap, s->used_bmap_size);
if (first_free == s->used_bmap_size) {
uint32_t new_usedsize;
int64_t bytes = to_allocate * s->cluster_size;
bytes += s->prealloc_size * BDRV_SECTOR_SIZE;
host_off = s->data_end * BDRV_SECTOR_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_co_truncate(bs->file, host_off + bytes,
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_co_pwrite_zeroes(bs->file, host_off, bytes, 0);
}
if (ret < 0) {
return ret;
}
new_usedsize = s->used_bmap_size + bytes / s->cluster_size;
s->used_bmap = bitmap_zero_extend(s->used_bmap, s->used_bmap_size,
new_usedsize);
s->used_bmap_size = new_usedsize;
} else {
int64_t next_used;
next_used = find_next_bit(s->used_bmap, s->used_bmap_size, first_free);
/* Not enough continuous clusters in the middle, adjust the size */
if (next_used - first_free < to_allocate) {
to_allocate = next_used - first_free;
*pnum = (idx + to_allocate) * s->tracks - sector_num;
}
host_off = s->data_start * BDRV_SECTOR_SIZE;
host_off += first_free * s->cluster_size;
/*
* No need to preallocate if we are using tail area from the above
* branch. In the other case we are likely re-using hole. Preallocate
* the space if required by the prealloc_mode.
*/
if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE &&
host_off < s->data_end * BDRV_SECTOR_SIZE) {
ret = bdrv_co_pwrite_zeroes(bs->file, host_off,
s->cluster_size * to_allocate, 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;
}
}
ret = mark_used(bs, s->used_bmap, s->used_bmap_size, host_off, to_allocate);
if (ret < 0) {
/* Image consistency is broken. Alarm! */
return ret;
}
for (i = 0; i < to_allocate; i++) {
parallels_set_bat_entry(s, idx + i,
host_off / BDRV_SECTOR_SIZE / s->off_multiplier);
host_off += s->cluster_size;
}
if (host_off > s->data_end * BDRV_SECTOR_SIZE) {
s->data_end = host_off / BDRV_SECTOR_SIZE;
}
return bat2sect(s, idx) + sector_num % s->tracks;
}
static int coroutine_fn GRAPH_RDLOCK
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_co_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 int coroutine_fn GRAPH_RDLOCK
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 int coroutine_fn GRAPH_RDLOCK
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 GRAPH_RDLOCK
parallels_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
{
int ret = 0;
uint32_t cluster, count;
BDRVParallelsState *s = bs->opaque;
/*
* The image does not support ZERO mark inside the BAT, which means that
* stale data could be exposed from the backing file.
*/
if (bs->backing) {
return -ENOTSUP;
}
if (!QEMU_IS_ALIGNED(offset, s->cluster_size)) {
return -ENOTSUP;
} else if (!QEMU_IS_ALIGNED(bytes, s->cluster_size)) {
return -ENOTSUP;
}
cluster = offset / s->cluster_size;
count = bytes / s->cluster_size;
qemu_co_mutex_lock(&s->lock);
for (; count > 0; cluster++, count--) {
int64_t host_off = bat2sect(s, cluster) << BDRV_SECTOR_BITS;
if (host_off == 0) {
continue;
}
ret = bdrv_co_pdiscard(bs->file, host_off, s->cluster_size);
if (ret < 0) {
goto done;
}
parallels_set_bat_entry(s, cluster, 0);
bitmap_clear(s->used_bmap, host_cluster_index(s, host_off), 1);
}
done:
qemu_co_mutex_unlock(&s->lock);
return ret;
}
static int coroutine_fn GRAPH_RDLOCK
parallels_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
BdrvRequestFlags flags)
{
/*
* The zero flag is missed in the Parallels format specification. We can
* resort to discard if we have no backing file (this condition is checked
* inside parallels_co_pdiscard().
*/
return parallels_co_pdiscard(bs, offset, bytes);
}
static void parallels_check_unclean(BlockDriverState *bs,
BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
if (!s->header_unclean) {
return;
}
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;
}
}
/*
* Returns true if data_off is correct, otherwise false. In both cases
* correct_offset is set to the proper value.
*/
static bool parallels_test_data_off(BDRVParallelsState *s,
int64_t file_nb_sectors,
uint32_t *correct_offset)
{
uint32_t data_off, min_off;
bool old_magic;
/*
* There are two slightly different image formats: with "WithoutFreeSpace"
* or "WithouFreSpacExt" magic words. Call the first one as "old magic".
* In such images data_off field can be zero. In this case the offset is
* calculated as the end of BAT table plus some padding to ensure sector
* size alignment.
*/
old_magic = !memcmp(s->header->magic, HEADER_MAGIC, 16);
min_off = DIV_ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
if (!old_magic) {
min_off = ROUND_UP(min_off, s->cluster_size / BDRV_SECTOR_SIZE);
}
if (correct_offset) {
*correct_offset = min_off;
}
data_off = le32_to_cpu(s->header->data_off);
if (data_off == 0 && old_magic) {
return true;
}
if (data_off < min_off || data_off > file_nb_sectors) {
return false;
}
if (correct_offset) {
*correct_offset = data_off;
}
return true;
}
static int coroutine_fn GRAPH_RDLOCK
parallels_check_data_off(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
int64_t file_size;
uint32_t data_off;
file_size = bdrv_co_nb_sectors(bs->file->bs);
if (file_size < 0) {
res->check_errors++;
return file_size;
}
if (parallels_test_data_off(s, file_size, &data_off)) {
return 0;
}
res->corruptions++;
if (fix & BDRV_FIX_ERRORS) {
int err;
s->header->data_off = cpu_to_le32(data_off);
s->data_start = data_off;
parallels_free_used_bitmap(bs);
err = parallels_fill_used_bitmap(bs);
if (err == -ENOMEM) {
res->check_errors++;
return err;
}
res->corruptions_fixed++;
}
fprintf(stderr, "%s data_off field has incorrect value\n",
fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
return 0;
}
static int coroutine_fn GRAPH_RDLOCK
parallels_check_outside_image(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
uint32_t i;
int64_t off, high_off, size;
size = bdrv_co_getlength(bs->file->bs);
if (size < 0) {
res->check_errors++;
return size;
}
high_off = 0;
for (i = 0; i < s->bat_size; i++) {
off = bat2sect(s, i) << BDRV_SECTOR_BITS;
if (off + s->cluster_size > size) {
fprintf(stderr, "%s cluster %u is outside image\n",
fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
res->corruptions++;
if (fix & BDRV_FIX_ERRORS) {
parallels_set_bat_entry(s, i, 0);
res->corruptions_fixed++;
}
continue;
}
if (high_off < off) {
high_off = off;
}
}
if (high_off == 0) {
res->image_end_offset = s->data_end << BDRV_SECTOR_BITS;
} else {
res->image_end_offset = high_off + s->cluster_size;
s->data_end = res->image_end_offset >> BDRV_SECTOR_BITS;
}
return 0;
}
static int coroutine_fn GRAPH_RDLOCK
parallels_check_leak(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix, bool explicit)
{
BDRVParallelsState *s = bs->opaque;
int64_t size;
int ret;
size = bdrv_co_getlength(bs->file->bs);
if (size < 0) {
res->check_errors++;
return size;
}
if (size > res->image_end_offset) {
int64_t count;
count = DIV_ROUND_UP(size - res->image_end_offset, s->cluster_size);
if (explicit) {
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_co_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++;
return ret;
}
if (explicit) {
res->leaks_fixed += count;
}
}
}
return 0;
}
static int coroutine_fn GRAPH_RDLOCK
parallels_check_duplicate(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
int64_t host_off, host_sector, guest_sector;
unsigned long *bitmap;
uint32_t i, bitmap_size, bat_entry;
int n, ret = 0;
uint64_t *buf = NULL;
bool fixed = false;
/*
* Create a bitmap of used clusters.
* If a bit is set, there is a BAT entry pointing to this cluster.
* Loop through the BAT entries, check bits relevant to an entry offset.
* If bit is set, this entry is duplicated. Otherwise set the bit.
*
* We shouldn't worry about newly allocated clusters outside the image
* because they are created higher then any existing cluster pointed by
* a BAT entry.
*/
bitmap_size = host_cluster_index(s, res->image_end_offset);
if (bitmap_size == 0) {
return 0;
}
if (res->image_end_offset % s->cluster_size) {
/* A not aligned image end leads to a bitmap shorter by 1 */
bitmap_size++;
}
bitmap = bitmap_new(bitmap_size);
buf = qemu_blockalign(bs, s->cluster_size);
for (i = 0; i < s->bat_size; i++) {
host_off = bat2sect(s, i) << BDRV_SECTOR_BITS;
if (host_off == 0) {
continue;
}
ret = mark_used(bs, bitmap, bitmap_size, host_off, 1);
assert(ret != -E2BIG);
if (ret == 0) {
continue;
}
/* this cluster duplicates another one */
fprintf(stderr, "%s duplicate offset in BAT entry %u\n",
fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
res->corruptions++;
if (!(fix & BDRV_FIX_ERRORS)) {
continue;
}
/*
* Reset the entry and allocate a new cluster
* for the relevant guest offset. In this way we let
* the lower layer to place the new cluster properly.
* Copy the original cluster to the allocated one.
* But before save the old offset value for repairing
* if we have an error.
*/
bat_entry = s->bat_bitmap[i];
parallels_set_bat_entry(s, i, 0);
ret = bdrv_co_pread(bs->file, host_off, s->cluster_size, buf, 0);
if (ret < 0) {
res->check_errors++;
goto out_repair_bat;
}
guest_sector = (i * (int64_t)s->cluster_size) >> BDRV_SECTOR_BITS;
host_sector = allocate_clusters(bs, guest_sector, s->tracks, &n);
if (host_sector < 0) {
res->check_errors++;
goto out_repair_bat;
}
host_off = host_sector << BDRV_SECTOR_BITS;
ret = bdrv_co_pwrite(bs->file, host_off, s->cluster_size, buf, 0);
if (ret < 0) {
res->check_errors++;
goto out_repair_bat;
}
if (host_off + s->cluster_size > res->image_end_offset) {
res->image_end_offset = host_off + s->cluster_size;
}
/*
* In the future allocate_cluster() will reuse holed offsets
* inside the image. Keep the used clusters bitmap content
* consistent for the new allocated clusters too.
*
* Note, clusters allocated outside the current image are not
* considered, and the bitmap size doesn't change. This specifically
* means that -E2BIG is OK.
*/
ret = mark_used(bs, bitmap, bitmap_size, host_off, 1);
if (ret == -EBUSY) {
res->check_errors++;
goto out_repair_bat;
}
fixed = true;
res->corruptions_fixed++;
}
if (fixed) {
/*
* When new clusters are allocated, the file size increases by
* 128 Mb. We need to truncate the file to the right size. Let
* the leak fix code make its job without res changing.
*/
ret = parallels_check_leak(bs, res, fix, false);
}
out_free:
g_free(buf);
g_free(bitmap);
return ret;
/*
* We can get here only from places where index and old_offset have
* meaningful values.
*/
out_repair_bat:
s->bat_bitmap[i] = bat_entry;
goto out_free;
}
static void parallels_collect_statistics(BlockDriverState *bs,
BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
int64_t off, prev_off;
uint32_t i;
res->bfi.total_clusters = s->bat_size;
res->bfi.compressed_clusters = 0; /* compression is not supported */
prev_off = 0;
for (i = 0; i < s->bat_size; i++) {
off = bat2sect(s, i) << BDRV_SECTOR_BITS;
/*
* If BDRV_FIX_ERRORS is not set, out-of-image BAT entries were not
* fixed. Skip not allocated and out-of-image BAT entries.
*/
if (off == 0 || off + s->cluster_size > res->image_end_offset) {
prev_off = 0;
continue;
}
if (prev_off != 0 && (prev_off + s->cluster_size) != off) {
res->bfi.fragmented_clusters++;
}
prev_off = off;
res->bfi.allocated_clusters++;
}
}
static int coroutine_fn GRAPH_RDLOCK
parallels_co_check(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix)
{
BDRVParallelsState *s = bs->opaque;
int ret;
WITH_QEMU_LOCK_GUARD(&s->lock) {
parallels_check_unclean(bs, res, fix);
ret = parallels_check_data_off(bs, res, fix);
if (ret < 0) {
return ret;
}
ret = parallels_check_outside_image(bs, res, fix);
if (ret < 0) {
return ret;
}
ret = parallels_check_leak(bs, res, fix, true);
if (ret < 0) {
return ret;
}
ret = parallels_check_duplicate(bs, res, fix);
if (ret < 0) {
return ret;
}
parallels_collect_statistics(bs, res, fix);
}
ret = bdrv_co_flush(bs);
if (ret < 0) {
res->check_errors++;
}
return ret;
}
static int coroutine_fn GRAPH_UNLOCKED
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_co_open_blockdev_ref(parallels_opts->file, errp);
if (bs == NULL) {
return -EIO;
}
blk = blk_co_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_co_pwrite(blk, 0, BDRV_SECTOR_SIZE, tmp, 0);
if (ret < 0) {
goto exit;
}
ret = blk_co_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
(bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
if (ret < 0) {
goto exit;
}
ret = 0;
out:
blk_co_unref(blk);
bdrv_co_unref(bs);
return ret;
exit:
error_setg_errno(errp, -ret, "Failed to create Parallels image");
goto out;
}
static int coroutine_fn GRAPH_UNLOCKED
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_co_create_file(filename, opts, errp);
if (ret < 0) {
goto done;
}
bs = bdrv_co_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_co_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_opts_prealloc(BlockDriverState *bs, QDict *options,
Error **errp)
{
int err;
char *buf;
int64_t bytes;
BDRVParallelsState *s = bs->opaque;
Error *local_err = NULL;
QemuOpts *opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, errp);
if (!opts) {
return -ENOMEM;
}
err = -EINVAL;
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
goto done;
}
bytes = qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
s->prealloc_size = bytes >> 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 done;
}
err = 0;
done:
qemu_opts_del(opts);
return err;
}
static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVParallelsState *s = bs->opaque;
ParallelsHeader ph;
int ret, size, i;
int64_t file_nb_sectors, sector;
uint32_t data_start;
bool need_check = false;
ret = parallels_opts_prealloc(bs, options, errp);
if (ret < 0) {
return ret;
}
ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
if (ret < 0) {
return ret;
}
file_nb_sectors = bdrv_nb_sectors(bs->file->bs);
if (file_nb_sectors < 0) {
return -EINVAL;
}
ret = bdrv_pread(bs->file, 0, sizeof(ph), &ph, 0);
if (ret < 0) {
return ret;
}
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");
return -EINVAL;
}
if (s->tracks > INT32_MAX/513) {
error_setg(errp, "Invalid image: Too big cluster");
return -EFBIG;
}
s->prealloc_size = MAX(s->tracks, s->prealloc_size);
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");
return -EFBIG;
}
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) {
return -ENOMEM;
}
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);
if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
need_check = s->header_unclean = true;
}
{
bool ok = parallels_test_data_off(s, file_nb_sectors, &data_start);
need_check = need_check || !ok;
}
s->data_start = data_start;
s->data_end = s->data_start;
if (s->data_end < (s->header_size >> BDRV_SECTOR_BITS)) {
/*
* 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;
}
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_setg(errp, "Migration blocker error");
goto fail;
}
qemu_co_mutex_init(&s->lock);
for (i = 0; i < s->bat_size; i++) {
sector = bat2sect(s, i);
if (sector + s->tracks > s->data_end) {
s->data_end = sector + s->tracks;
}
}
need_check = need_check || s->data_end > file_nb_sectors;
if (!need_check) {
ret = parallels_fill_used_bitmap(bs);
if (ret == -ENOMEM) {
goto fail;
}
need_check = need_check || ret < 0; /* These are correctable errors */
}
/*
* We don't repair the image here if it's opened for checks. Also we don't
* want to change inactive images and can't change readonly images.
*/
if ((flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) || !(flags & BDRV_O_RDWR)) {
return 0;
}
/* Repair the image if corruption was detected. */
if (need_check) {
BdrvCheckResult res;
ret = bdrv_check(bs, &res, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not repair corrupted image");
migrate_del_blocker(s->migration_blocker);
goto fail;
}
}
return 0;
fail_format:
error_setg(errp, "Image not in Parallels format");
return -EINVAL;
fail:
/*
* "s" object was allocated by g_malloc0 so we can safely
* try to free its fields even they were not allocated.
*/
parallels_free_used_bitmap(bs);
error_free(s->migration_blocker);
g_free(s->bat_dirty_bmap);
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);
}
parallels_free_used_bitmap(bs);
g_free(s->bat_dirty_bmap);
qemu_vfree(s->header);
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
}
static bool parallels_is_support_dirty_bitmaps(BlockDriverState *bs)
{
return 1;
}
static BlockDriver bdrv_parallels = {
.format_name = "parallels",
.instance_size = sizeof(BDRVParallelsState),
.create_opts = &parallels_create_opts,
.is_format = true,
.supports_backing = true,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_supports_persistent_dirty_bitmap = parallels_is_support_dirty_bitmaps,
.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_co_flush_to_os = parallels_co_flush_to_os,
.bdrv_co_readv = parallels_co_readv,
.bdrv_co_writev = parallels_co_writev,
.bdrv_co_create = parallels_co_create,
.bdrv_co_create_opts = parallels_co_create_opts,
.bdrv_co_check = parallels_co_check,
.bdrv_co_pdiscard = parallels_co_pdiscard,
.bdrv_co_pwrite_zeroes = parallels_co_pwrite_zeroes,
};
static void bdrv_parallels_init(void)
{
bdrv_register(&bdrv_parallels);
}
block_init(bdrv_parallels_init);
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