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qemu-e2k/qemu-img.c
Kevin Wolf 87a1b3e381 qemu-img rebase: Fix for undersized backing files 
Backing files may be smaller than the corresponding COW file. When
reading directly from the backing file, qemu-img rebase must consider
this and assume zero sectors after the end of backing files.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-15 12:40:08 +01:00

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/*
* QEMU disk image utility
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* 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 "qemu-option.h"
#include "qemu-error.h"
#include "osdep.h"
#include "sysemu.h"
#include "block_int.h"
#include <stdio.h>
#ifdef _WIN32
#include <windows.h>
#endif
typedef struct img_cmd_t {
const char *name;
int (*handler)(int argc, char **argv);
} img_cmd_t;
/* Default to cache=writeback as data integrity is not important for qemu-tcg. */
#define BDRV_O_FLAGS BDRV_O_CACHE_WB
#define BDRV_DEFAULT_CACHE "writeback"
static void format_print(void *opaque, const char *name)
{
printf(" %s", name);
}
/* Please keep in synch with qemu-img.texi */
static void help(void)
{
const char *help_msg =
"qemu-img version " QEMU_VERSION ", Copyright (c) 2004-2008 Fabrice Bellard\n"
"usage: qemu-img command [command options]\n"
"QEMU disk image utility\n"
"\n"
"Command syntax:\n"
#define DEF(option, callback, arg_string) \
" " arg_string "\n"
#include "qemu-img-cmds.h"
#undef DEF
#undef GEN_DOCS
"\n"
"Command parameters:\n"
" 'filename' is a disk image filename\n"
" 'fmt' is the disk image format. It is guessed automatically in most cases\n"
" 'cache' is the cache mode used to write the output disk image, the valid\n"
" options are: 'none', 'writeback' (default), 'writethrough', 'directsync'\n"
" and 'unsafe'\n"
" 'size' is the disk image size in bytes. Optional suffixes\n"
" 'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M)\n"
" and T (terabyte, 1024G) are supported. 'b' is ignored.\n"
" 'output_filename' is the destination disk image filename\n"
" 'output_fmt' is the destination format\n"
" 'options' is a comma separated list of format specific options in a\n"
" name=value format. Use -o ? for an overview of the options supported by the\n"
" used format\n"
" '-c' indicates that target image must be compressed (qcow format only)\n"
" '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
" match exactly. The image doesn't need a working backing file before\n"
" rebasing in this case (useful for renaming the backing file)\n"
" '-h' with or without a command shows this help and lists the supported formats\n"
" '-p' show progress of command (only certain commands)\n"
" '-S' indicates the consecutive number of bytes that must contain only zeros\n"
" for qemu-img to create a sparse image during conversion\n"
"\n"
"Parameters to snapshot subcommand:\n"
" 'snapshot' is the name of the snapshot to create, apply or delete\n"
" '-a' applies a snapshot (revert disk to saved state)\n"
" '-c' creates a snapshot\n"
" '-d' deletes a snapshot\n"
" '-l' lists all snapshots in the given image\n";
printf("%s\nSupported formats:", help_msg);
bdrv_iterate_format(format_print, NULL);
printf("\n");
exit(1);
}
#if defined(WIN32)
/* XXX: put correct support for win32 */
static int read_password(char *buf, int buf_size)
{
int c, i;
printf("Password: ");
fflush(stdout);
i = 0;
for(;;) {
c = getchar();
if (c == '\n')
break;
if (i < (buf_size - 1))
buf[i++] = c;
}
buf[i] = '\0';
return 0;
}
#else
#include <termios.h>
static struct termios oldtty;
static void term_exit(void)
{
tcsetattr (0, TCSANOW, &oldtty);
}
static void term_init(void)
{
struct termios tty;
tcgetattr (0, &tty);
oldtty = tty;
tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
|INLCR|IGNCR|ICRNL|IXON);
tty.c_oflag |= OPOST;
tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
tty.c_cflag &= ~(CSIZE|PARENB);
tty.c_cflag |= CS8;
tty.c_cc[VMIN] = 1;
tty.c_cc[VTIME] = 0;
tcsetattr (0, TCSANOW, &tty);
atexit(term_exit);
}
static int read_password(char *buf, int buf_size)
{
uint8_t ch;
int i, ret;
printf("password: ");
fflush(stdout);
term_init();
i = 0;
for(;;) {
ret = read(0, &ch, 1);
if (ret == -1) {
if (errno == EAGAIN || errno == EINTR) {
continue;
} else {
ret = -1;
break;
}
} else if (ret == 0) {
ret = -1;
break;
} else {
if (ch == '\r') {
ret = 0;
break;
}
if (i < (buf_size - 1))
buf[i++] = ch;
}
}
term_exit();
buf[i] = '\0';
printf("\n");
return ret;
}
#endif
static int print_block_option_help(const char *filename, const char *fmt)
{
BlockDriver *drv, *proto_drv;
QEMUOptionParameter *create_options = NULL;
/* Find driver and parse its options */
drv = bdrv_find_format(fmt);
if (!drv) {
error_report("Unknown file format '%s'", fmt);
return 1;
}
proto_drv = bdrv_find_protocol(filename);
if (!proto_drv) {
error_report("Unknown protocol '%s'", filename);
return 1;
}
create_options = append_option_parameters(create_options,
drv->create_options);
create_options = append_option_parameters(create_options,
proto_drv->create_options);
print_option_help(create_options);
free_option_parameters(create_options);
return 0;
}
static BlockDriverState *bdrv_new_open(const char *filename,
const char *fmt,
int flags)
{
BlockDriverState *bs;
BlockDriver *drv;
char password[256];
int ret;
bs = bdrv_new("image");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv) {
error_report("Unknown file format '%s'", fmt);
goto fail;
}
} else {
drv = NULL;
}
ret = bdrv_open(bs, filename, flags, drv);
if (ret < 0) {
error_report("Could not open '%s': %s", filename, strerror(-ret));
goto fail;
}
if (bdrv_is_encrypted(bs)) {
printf("Disk image '%s' is encrypted.\n", filename);
if (read_password(password, sizeof(password)) < 0) {
error_report("No password given");
goto fail;
}
if (bdrv_set_key(bs, password) < 0) {
error_report("invalid password");
goto fail;
}
}
return bs;
fail:
if (bs) {
bdrv_delete(bs);
}
return NULL;
}
static int add_old_style_options(const char *fmt, QEMUOptionParameter *list,
const char *base_filename,
const char *base_fmt)
{
if (base_filename) {
if (set_option_parameter(list, BLOCK_OPT_BACKING_FILE, base_filename)) {
error_report("Backing file not supported for file format '%s'",
fmt);
return -1;
}
}
if (base_fmt) {
if (set_option_parameter(list, BLOCK_OPT_BACKING_FMT, base_fmt)) {
error_report("Backing file format not supported for file "
"format '%s'", fmt);
return -1;
}
}
return 0;
}
static int img_create(int argc, char **argv)
{
int c, ret = 0;
uint64_t img_size = -1;
const char *fmt = "raw";
const char *base_fmt = NULL;
const char *filename;
const char *base_filename = NULL;
char *options = NULL;
for(;;) {
c = getopt(argc, argv, "F:b:f:he6o:");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
break;
case 'F':
base_fmt = optarg;
break;
case 'b':
base_filename = optarg;
break;
case 'f':
fmt = optarg;
break;
case 'e':
error_report("option -e is deprecated, please use \'-o "
"encryption\' instead!");
return 1;
case '6':
error_report("option -6 is deprecated, please use \'-o "
"compat6\' instead!");
return 1;
case 'o':
options = optarg;
break;
}
}
/* Get the filename */
if (optind >= argc) {
help();
}
filename = argv[optind++];
/* Get image size, if specified */
if (optind < argc) {
int64_t sval;
char *end;
sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
if (sval < 0 || *end) {
error_report("Invalid image size specified! You may use k, M, G or "
"T suffixes for ");
error_report("kilobytes, megabytes, gigabytes and terabytes.");
ret = -1;
goto out;
}
img_size = (uint64_t)sval;
}
if (options && !strcmp(options, "?")) {
ret = print_block_option_help(filename, fmt);
goto out;
}
ret = bdrv_img_create(filename, fmt, base_filename, base_fmt,
options, img_size, BDRV_O_FLAGS);
out:
if (ret) {
return 1;
}
return 0;
}
/*
* Checks an image for consistency. Exit codes:
*
* 0 - Check completed, image is good
* 1 - Check not completed because of internal errors
* 2 - Check completed, image is corrupted
* 3 - Check completed, image has leaked clusters, but is good otherwise
*/
static int img_check(int argc, char **argv)
{
int c, ret;
const char *filename, *fmt;
BlockDriverState *bs;
BdrvCheckResult result;
fmt = NULL;
for(;;) {
c = getopt(argc, argv, "f:h");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc) {
help();
}
filename = argv[optind++];
bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS);
if (!bs) {
return 1;
}
ret = bdrv_check(bs, &result);
if (ret == -ENOTSUP) {
error_report("This image format does not support checks");
bdrv_delete(bs);
return 1;
}
if (!(result.corruptions || result.leaks || result.check_errors)) {
printf("No errors were found on the image.\n");
} else {
if (result.corruptions) {
printf("\n%d errors were found on the image.\n"
"Data may be corrupted, or further writes to the image "
"may corrupt it.\n",
result.corruptions);
}
if (result.leaks) {
printf("\n%d leaked clusters were found on the image.\n"
"This means waste of disk space, but no harm to data.\n",
result.leaks);
}
if (result.check_errors) {
printf("\n%d internal errors have occurred during the check.\n",
result.check_errors);
}
}
bdrv_delete(bs);
if (ret < 0 || result.check_errors) {
printf("\nAn error has occurred during the check: %s\n"
"The check is not complete and may have missed error.\n",
strerror(-ret));
return 1;
}
if (result.corruptions) {
return 2;
} else if (result.leaks) {
return 3;
} else {
return 0;
}
}
static int img_commit(int argc, char **argv)
{
int c, ret, flags;
const char *filename, *fmt, *cache;
BlockDriverState *bs;
fmt = NULL;
cache = BDRV_DEFAULT_CACHE;
for(;;) {
c = getopt(argc, argv, "f:ht:");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
case 't':
cache = optarg;
break;
}
}
if (optind >= argc) {
help();
}
filename = argv[optind++];
flags = BDRV_O_RDWR;
ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
return -1;
}
bs = bdrv_new_open(filename, fmt, flags);
if (!bs) {
return 1;
}
ret = bdrv_commit(bs);
switch(ret) {
case 0:
printf("Image committed.\n");
break;
case -ENOENT:
error_report("No disk inserted");
break;
case -EACCES:
error_report("Image is read-only");
break;
case -ENOTSUP:
error_report("Image is already committed");
break;
default:
error_report("Error while committing image");
break;
}
bdrv_delete(bs);
if (ret) {
return 1;
}
return 0;
}
/*
* Checks whether the sector is not a zero sector.
*
* Attention! The len must be a multiple of 4 * sizeof(long) due to
* restriction of optimizations in this function.
*/
static int is_not_zero(const uint8_t *sector, int len)
{
/*
* Use long as the biggest available internal data type that fits into the
* CPU register and unroll the loop to smooth out the effect of memory
* latency.
*/
int i;
long d0, d1, d2, d3;
const long * const data = (const long *) sector;
len /= sizeof(long);
for(i = 0; i < len; i += 4) {
d0 = data[i + 0];
d1 = data[i + 1];
d2 = data[i + 2];
d3 = data[i + 3];
if (d0 || d1 || d2 || d3) {
return 1;
}
}
return 0;
}
/*
* Returns true iff the first sector pointed to by 'buf' contains at least
* a non-NUL byte.
*
* 'pnum' is set to the number of sectors (including and immediately following
* the first one) that are known to be in the same allocated/unallocated state.
*/
static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
{
int v, i;
if (n <= 0) {
*pnum = 0;
return 0;
}
v = is_not_zero(buf, 512);
for(i = 1; i < n; i++) {
buf += 512;
if (v != is_not_zero(buf, 512))
break;
}
*pnum = i;
return v;
}
/*
* Like is_allocated_sectors, but if the buffer starts with a used sector,
* up to 'min' consecutive sectors containing zeros are ignored. This avoids
* breaking up write requests for only small sparse areas.
*/
static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
int min)
{
int ret;
int num_checked, num_used;
if (n < min) {
min = n;
}
ret = is_allocated_sectors(buf, n, pnum);
if (!ret) {
return ret;
}
num_used = *pnum;
buf += BDRV_SECTOR_SIZE * *pnum;
n -= *pnum;
num_checked = num_used;
while (n > 0) {
ret = is_allocated_sectors(buf, n, pnum);
buf += BDRV_SECTOR_SIZE * *pnum;
n -= *pnum;
num_checked += *pnum;
if (ret) {
num_used = num_checked;
} else if (*pnum >= min) {
break;
}
}
*pnum = num_used;
return 1;
}
/*
* Compares two buffers sector by sector. Returns 0 if the first sector of both
* buffers matches, non-zero otherwise.
*
* pnum is set to the number of sectors (including and immediately following
* the first one) that are known to have the same comparison result
*/
static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
int *pnum)
{
int res, i;
if (n <= 0) {
*pnum = 0;
return 0;
}
res = !!memcmp(buf1, buf2, 512);
for(i = 1; i < n; i++) {
buf1 += 512;
buf2 += 512;
if (!!memcmp(buf1, buf2, 512) != res) {
break;
}
}
*pnum = i;
return res;
}
#define IO_BUF_SIZE (2 * 1024 * 1024)
static int img_convert(int argc, char **argv)
{
int c, ret = 0, n, n1, bs_n, bs_i, compress, cluster_size, cluster_sectors;
int progress = 0, flags;
const char *fmt, *out_fmt, *cache, *out_baseimg, *out_filename;
BlockDriver *drv, *proto_drv;
BlockDriverState **bs = NULL, *out_bs = NULL;
int64_t total_sectors, nb_sectors, sector_num, bs_offset;
uint64_t bs_sectors;
uint8_t * buf = NULL;
const uint8_t *buf1;
BlockDriverInfo bdi;
QEMUOptionParameter *param = NULL, *create_options = NULL;
QEMUOptionParameter *out_baseimg_param;
char *options = NULL;
const char *snapshot_name = NULL;
float local_progress;
int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
fmt = NULL;
out_fmt = "raw";
cache = "unsafe";
out_baseimg = NULL;
compress = 0;
for(;;) {
c = getopt(argc, argv, "f:O:B:s:hce6o:pS:t:");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
case 'O':
out_fmt = optarg;
break;
case 'B':
out_baseimg = optarg;
break;
case 'c':
compress = 1;
break;
case 'e':
error_report("option -e is deprecated, please use \'-o "
"encryption\' instead!");
return 1;
case '6':
error_report("option -6 is deprecated, please use \'-o "
"compat6\' instead!");
return 1;
case 'o':
options = optarg;
break;
case 's':
snapshot_name = optarg;
break;
case 'S':
{
int64_t sval;
char *end;
sval = strtosz_suffix(optarg, &end, STRTOSZ_DEFSUFFIX_B);
if (sval < 0 || *end) {
error_report("Invalid minimum zero buffer size for sparse output specified");
return 1;
}
min_sparse = sval / BDRV_SECTOR_SIZE;
break;
}
case 'p':
progress = 1;
break;
case 't':
cache = optarg;
break;
}
}
bs_n = argc - optind - 1;
if (bs_n < 1) {
help();
}
out_filename = argv[argc - 1];
if (options && !strcmp(options, "?")) {
ret = print_block_option_help(out_filename, out_fmt);
goto out;
}
if (bs_n > 1 && out_baseimg) {
error_report("-B makes no sense when concatenating multiple input "
"images");
ret = -1;
goto out;
}
qemu_progress_init(progress, 2.0);
qemu_progress_print(0, 100);
bs = g_malloc0(bs_n * sizeof(BlockDriverState *));
total_sectors = 0;
for (bs_i = 0; bs_i < bs_n; bs_i++) {
bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt, BDRV_O_FLAGS);
if (!bs[bs_i]) {
error_report("Could not open '%s'", argv[optind + bs_i]);
ret = -1;
goto out;
}
bdrv_get_geometry(bs[bs_i], &bs_sectors);
total_sectors += bs_sectors;
}
if (snapshot_name != NULL) {
if (bs_n > 1) {
error_report("No support for concatenating multiple snapshot");
ret = -1;
goto out;
}
if (bdrv_snapshot_load_tmp(bs[0], snapshot_name) < 0) {
error_report("Failed to load snapshot");
ret = -1;
goto out;
}
}
/* Find driver and parse its options */
drv = bdrv_find_format(out_fmt);
if (!drv) {
error_report("Unknown file format '%s'", out_fmt);
ret = -1;
goto out;
}
proto_drv = bdrv_find_protocol(out_filename);
if (!proto_drv) {
error_report("Unknown protocol '%s'", out_filename);
ret = -1;
goto out;
}
create_options = append_option_parameters(create_options,
drv->create_options);
create_options = append_option_parameters(create_options,
proto_drv->create_options);
if (options) {
param = parse_option_parameters(options, create_options, param);
if (param == NULL) {
error_report("Invalid options for file format '%s'.", out_fmt);
ret = -1;
goto out;
}
} else {
param = parse_option_parameters("", create_options, param);
}
set_option_parameter_int(param, BLOCK_OPT_SIZE, total_sectors * 512);
ret = add_old_style_options(out_fmt, param, out_baseimg, NULL);
if (ret < 0) {
goto out;
}
/* Get backing file name if -o backing_file was used */
out_baseimg_param = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
if (out_baseimg_param) {
out_baseimg = out_baseimg_param->value.s;
}
/* Check if compression is supported */
if (compress) {
QEMUOptionParameter *encryption =
get_option_parameter(param, BLOCK_OPT_ENCRYPT);
QEMUOptionParameter *preallocation =
get_option_parameter(param, BLOCK_OPT_PREALLOC);
if (!drv->bdrv_write_compressed) {
error_report("Compression not supported for this file format");
ret = -1;
goto out;
}
if (encryption && encryption->value.n) {
error_report("Compression and encryption not supported at "
"the same time");
ret = -1;
goto out;
}
if (preallocation && preallocation->value.s
&& strcmp(preallocation->value.s, "off"))
{
error_report("Compression and preallocation not supported at "
"the same time");
ret = -1;
goto out;
}
}
/* Create the new image */
ret = bdrv_create(drv, out_filename, param);
if (ret < 0) {
if (ret == -ENOTSUP) {
error_report("Formatting not supported for file format '%s'",
out_fmt);
} else if (ret == -EFBIG) {
error_report("The image size is too large for file format '%s'",
out_fmt);
} else {
error_report("%s: error while converting %s: %s",
out_filename, out_fmt, strerror(-ret));
}
goto out;
}
flags = BDRV_O_RDWR;
ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
return -1;
}
out_bs = bdrv_new_open(out_filename, out_fmt, flags);
if (!out_bs) {
ret = -1;
goto out;
}
bs_i = 0;
bs_offset = 0;
bdrv_get_geometry(bs[0], &bs_sectors);
buf = qemu_blockalign(out_bs, IO_BUF_SIZE);
if (compress) {
ret = bdrv_get_info(out_bs, &bdi);
if (ret < 0) {
error_report("could not get block driver info");
goto out;
}
cluster_size = bdi.cluster_size;
if (cluster_size <= 0 || cluster_size > IO_BUF_SIZE) {
error_report("invalid cluster size");
ret = -1;
goto out;
}
cluster_sectors = cluster_size >> 9;
sector_num = 0;
nb_sectors = total_sectors;
local_progress = (float)100 /
(nb_sectors / MIN(nb_sectors, cluster_sectors));
for(;;) {
int64_t bs_num;
int remainder;
uint8_t *buf2;
nb_sectors = total_sectors - sector_num;
if (nb_sectors <= 0)
break;
if (nb_sectors >= cluster_sectors)
n = cluster_sectors;
else
n = nb_sectors;
bs_num = sector_num - bs_offset;
assert (bs_num >= 0);
remainder = n;
buf2 = buf;
while (remainder > 0) {
int nlow;
while (bs_num == bs_sectors) {
bs_i++;
assert (bs_i < bs_n);
bs_offset += bs_sectors;
bdrv_get_geometry(bs[bs_i], &bs_sectors);
bs_num = 0;
/* printf("changing part: sector_num=%" PRId64 ", "
"bs_i=%d, bs_offset=%" PRId64 ", bs_sectors=%" PRId64
"\n", sector_num, bs_i, bs_offset, bs_sectors); */
}
assert (bs_num < bs_sectors);
nlow = (remainder > bs_sectors - bs_num) ? bs_sectors - bs_num : remainder;
ret = bdrv_read(bs[bs_i], bs_num, buf2, nlow);
if (ret < 0) {
error_report("error while reading sector %" PRId64 ": %s",
bs_num, strerror(-ret));
goto out;
}
buf2 += nlow * 512;
bs_num += nlow;
remainder -= nlow;
}
assert (remainder == 0);
if (n < cluster_sectors) {
memset(buf + n * 512, 0, cluster_size - n * 512);
}
if (is_not_zero(buf, cluster_size)) {
ret = bdrv_write_compressed(out_bs, sector_num, buf,
cluster_sectors);
if (ret != 0) {
error_report("error while compressing sector %" PRId64
": %s", sector_num, strerror(-ret));
goto out;
}
}
sector_num += n;
qemu_progress_print(local_progress, 100);
}
/* signal EOF to align */
bdrv_write_compressed(out_bs, 0, NULL, 0);
} else {
int has_zero_init = bdrv_has_zero_init(out_bs);
sector_num = 0; // total number of sectors converted so far
nb_sectors = total_sectors - sector_num;
local_progress = (float)100 /
(nb_sectors / MIN(nb_sectors, IO_BUF_SIZE / 512));
for(;;) {
nb_sectors = total_sectors - sector_num;
if (nb_sectors <= 0) {
break;
}
if (nb_sectors >= (IO_BUF_SIZE / 512)) {
n = (IO_BUF_SIZE / 512);
} else {
n = nb_sectors;
}
while (sector_num - bs_offset >= bs_sectors) {
bs_i ++;
assert (bs_i < bs_n);
bs_offset += bs_sectors;
bdrv_get_geometry(bs[bs_i], &bs_sectors);
/* printf("changing part: sector_num=%" PRId64 ", bs_i=%d, "
"bs_offset=%" PRId64 ", bs_sectors=%" PRId64 "\n",
sector_num, bs_i, bs_offset, bs_sectors); */
}
if (n > bs_offset + bs_sectors - sector_num) {
n = bs_offset + bs_sectors - sector_num;
}
if (has_zero_init) {
/* If the output image is being created as a copy on write image,
assume that sectors which are unallocated in the input image
are present in both the output's and input's base images (no
need to copy them). */
if (out_baseimg) {
if (!bdrv_is_allocated(bs[bs_i], sector_num - bs_offset,
n, &n1)) {
sector_num += n1;
continue;
}
/* The next 'n1' sectors are allocated in the input image. Copy
only those as they may be followed by unallocated sectors. */
n = n1;
}
} else {
n1 = n;
}
ret = bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n);
if (ret < 0) {
error_report("error while reading sector %" PRId64 ": %s",
sector_num - bs_offset, strerror(-ret));
goto out;
}
/* NOTE: at the same time we convert, we do not write zero
sectors to have a chance to compress the image. Ideally, we
should add a specific call to have the info to go faster */
buf1 = buf;
while (n > 0) {
/* If the output image is being created as a copy on write image,
copy all sectors even the ones containing only NUL bytes,
because they may differ from the sectors in the base image.
If the output is to a host device, we also write out
sectors that are entirely 0, since whatever data was
already there is garbage, not 0s. */
if (!has_zero_init || out_baseimg ||
is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
ret = bdrv_write(out_bs, sector_num, buf1, n1);
if (ret < 0) {
error_report("error while writing sector %" PRId64
": %s", sector_num, strerror(-ret));
goto out;
}
}
sector_num += n1;
n -= n1;
buf1 += n1 * 512;
}
qemu_progress_print(local_progress, 100);
}
}
out:
qemu_progress_end();
free_option_parameters(create_options);
free_option_parameters(param);
qemu_vfree(buf);
if (out_bs) {
bdrv_delete(out_bs);
}
if (bs) {
for (bs_i = 0; bs_i < bs_n; bs_i++) {
if (bs[bs_i]) {
bdrv_delete(bs[bs_i]);
}
}
g_free(bs);
}
if (ret) {
return 1;
}
return 0;
}
static void dump_snapshots(BlockDriverState *bs)
{
QEMUSnapshotInfo *sn_tab, *sn;
int nb_sns, i;
char buf[256];
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns <= 0)
return;
printf("Snapshot list:\n");
printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
for(i = 0; i < nb_sns; i++) {
sn = &sn_tab[i];
printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
}
g_free(sn_tab);
}
static int img_info(int argc, char **argv)
{
int c;
const char *filename, *fmt;
BlockDriverState *bs;
char fmt_name[128], size_buf[128], dsize_buf[128];
uint64_t total_sectors;
int64_t allocated_size;
char backing_filename[1024];
char backing_filename2[1024];
BlockDriverInfo bdi;
fmt = NULL;
for(;;) {
c = getopt(argc, argv, "f:h");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc) {
help();
}
filename = argv[optind++];
bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING);
if (!bs) {
return 1;
}
bdrv_get_format(bs, fmt_name, sizeof(fmt_name));
bdrv_get_geometry(bs, &total_sectors);
get_human_readable_size(size_buf, sizeof(size_buf), total_sectors * 512);
allocated_size = bdrv_get_allocated_file_size(bs);
if (allocated_size < 0) {
snprintf(dsize_buf, sizeof(dsize_buf), "unavailable");
} else {
get_human_readable_size(dsize_buf, sizeof(dsize_buf),
allocated_size);
}
printf("image: %s\n"
"file format: %s\n"
"virtual size: %s (%" PRId64 " bytes)\n"
"disk size: %s\n",
filename, fmt_name, size_buf,
(total_sectors * 512),
dsize_buf);
if (bdrv_is_encrypted(bs)) {
printf("encrypted: yes\n");
}
if (bdrv_get_info(bs, &bdi) >= 0) {
if (bdi.cluster_size != 0) {
printf("cluster_size: %d\n", bdi.cluster_size);
}
}
bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
if (backing_filename[0] != '\0') {
path_combine(backing_filename2, sizeof(backing_filename2),
filename, backing_filename);
printf("backing file: %s (actual path: %s)\n",
backing_filename,
backing_filename2);
}
dump_snapshots(bs);
bdrv_delete(bs);
return 0;
}
#define SNAPSHOT_LIST 1
#define SNAPSHOT_CREATE 2
#define SNAPSHOT_APPLY 3
#define SNAPSHOT_DELETE 4
static int img_snapshot(int argc, char **argv)
{
BlockDriverState *bs;
QEMUSnapshotInfo sn;
char *filename, *snapshot_name = NULL;
int c, ret = 0, bdrv_oflags;
int action = 0;
qemu_timeval tv;
bdrv_oflags = BDRV_O_FLAGS | BDRV_O_RDWR;
/* Parse commandline parameters */
for(;;) {
c = getopt(argc, argv, "la:c:d:h");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
return 0;
case 'l':
if (action) {
help();
return 0;
}
action = SNAPSHOT_LIST;
bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
break;
case 'a':
if (action) {
help();
return 0;
}
action = SNAPSHOT_APPLY;
snapshot_name = optarg;
break;
case 'c':
if (action) {
help();
return 0;
}
action = SNAPSHOT_CREATE;
snapshot_name = optarg;
break;
case 'd':
if (action) {
help();
return 0;
}
action = SNAPSHOT_DELETE;
snapshot_name = optarg;
break;
}
}
if (optind >= argc) {
help();
}
filename = argv[optind++];
/* Open the image */
bs = bdrv_new_open(filename, NULL, bdrv_oflags);
if (!bs) {
return 1;
}
/* Perform the requested action */
switch(action) {
case SNAPSHOT_LIST:
dump_snapshots(bs);
break;
case SNAPSHOT_CREATE:
memset(&sn, 0, sizeof(sn));
pstrcpy(sn.name, sizeof(sn.name), snapshot_name);
qemu_gettimeofday(&tv);
sn.date_sec = tv.tv_sec;
sn.date_nsec = tv.tv_usec * 1000;
ret = bdrv_snapshot_create(bs, &sn);
if (ret) {
error_report("Could not create snapshot '%s': %d (%s)",
snapshot_name, ret, strerror(-ret));
}
break;
case SNAPSHOT_APPLY:
ret = bdrv_snapshot_goto(bs, snapshot_name);
if (ret) {
error_report("Could not apply snapshot '%s': %d (%s)",
snapshot_name, ret, strerror(-ret));
}
break;
case SNAPSHOT_DELETE:
ret = bdrv_snapshot_delete(bs, snapshot_name);
if (ret) {
error_report("Could not delete snapshot '%s': %d (%s)",
snapshot_name, ret, strerror(-ret));
}
break;
}
/* Cleanup */
bdrv_delete(bs);
if (ret) {
return 1;
}
return 0;
}
static int img_rebase(int argc, char **argv)
{
BlockDriverState *bs, *bs_old_backing = NULL, *bs_new_backing = NULL;
BlockDriver *old_backing_drv, *new_backing_drv;
char *filename;
const char *fmt, *cache, *out_basefmt, *out_baseimg;
int c, flags, ret;
int unsafe = 0;
int progress = 0;
/* Parse commandline parameters */
fmt = NULL;
cache = BDRV_DEFAULT_CACHE;
out_baseimg = NULL;
out_basefmt = NULL;
for(;;) {
c = getopt(argc, argv, "uhf:F:b:pt:");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
return 0;
case 'f':
fmt = optarg;
break;
case 'F':
out_basefmt = optarg;
break;
case 'b':
out_baseimg = optarg;
break;
case 'u':
unsafe = 1;
break;
case 'p':
progress = 1;
break;
case 't':
cache = optarg;
break;
}
}
if ((optind >= argc) || (!unsafe && !out_baseimg)) {
help();
}
filename = argv[optind++];
qemu_progress_init(progress, 2.0);
qemu_progress_print(0, 100);
flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
return -1;
}
/*
* Open the images.
*
* Ignore the old backing file for unsafe rebase in case we want to correct
* the reference to a renamed or moved backing file.
*/
bs = bdrv_new_open(filename, fmt, flags);
if (!bs) {
return 1;
}
/* Find the right drivers for the backing files */
old_backing_drv = NULL;
new_backing_drv = NULL;
if (!unsafe && bs->backing_format[0] != '\0') {
old_backing_drv = bdrv_find_format(bs->backing_format);
if (old_backing_drv == NULL) {
error_report("Invalid format name: '%s'", bs->backing_format);
ret = -1;
goto out;
}
}
if (out_basefmt != NULL) {
new_backing_drv = bdrv_find_format(out_basefmt);
if (new_backing_drv == NULL) {
error_report("Invalid format name: '%s'", out_basefmt);
ret = -1;
goto out;
}
}
/* For safe rebasing we need to compare old and new backing file */
if (unsafe) {
/* Make the compiler happy */
bs_old_backing = NULL;
bs_new_backing = NULL;
} else {
char backing_name[1024];
bs_old_backing = bdrv_new("old_backing");
bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
ret = bdrv_open(bs_old_backing, backing_name, BDRV_O_FLAGS,
old_backing_drv);
if (ret) {
error_report("Could not open old backing file '%s'", backing_name);
goto out;
}
bs_new_backing = bdrv_new("new_backing");
ret = bdrv_open(bs_new_backing, out_baseimg, BDRV_O_FLAGS,
new_backing_drv);
if (ret) {
error_report("Could not open new backing file '%s'", out_baseimg);
goto out;
}
}
/*
* Check each unallocated cluster in the COW file. If it is unallocated,
* accesses go to the backing file. We must therefore compare this cluster
* in the old and new backing file, and if they differ we need to copy it
* from the old backing file into the COW file.
*
* If qemu-img crashes during this step, no harm is done. The content of
* the image is the same as the original one at any time.
*/
if (!unsafe) {
uint64_t num_sectors;
uint64_t old_backing_num_sectors;
uint64_t new_backing_num_sectors;
uint64_t sector;
int n;
uint8_t * buf_old;
uint8_t * buf_new;
float local_progress;
buf_old = qemu_blockalign(bs, IO_BUF_SIZE);
buf_new = qemu_blockalign(bs, IO_BUF_SIZE);
bdrv_get_geometry(bs, &num_sectors);
bdrv_get_geometry(bs_old_backing, &old_backing_num_sectors);
bdrv_get_geometry(bs_new_backing, &new_backing_num_sectors);
local_progress = (float)100 /
(num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
for (sector = 0; sector < num_sectors; sector += n) {
/* How many sectors can we handle with the next read? */
if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
n = (IO_BUF_SIZE / 512);
} else {
n = num_sectors - sector;
}
/* If the cluster is allocated, we don't need to take action */
ret = bdrv_is_allocated(bs, sector, n, &n);
if (ret) {
continue;
}
/*
* Read old and new backing file and take into consideration that
* backing files may be smaller than the COW image.
*/
if (sector >= old_backing_num_sectors) {
memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
} else {
if (sector + n > old_backing_num_sectors) {
n = old_backing_num_sectors - sector;
}
ret = bdrv_read(bs_old_backing, sector, buf_old, n);
if (ret < 0) {
error_report("error while reading from old backing file");
goto out;
}
}
if (sector >= new_backing_num_sectors) {
memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
} else {
if (sector + n > new_backing_num_sectors) {
n = new_backing_num_sectors - sector;
}
ret = bdrv_read(bs_new_backing, sector, buf_new, n);
if (ret < 0) {
error_report("error while reading from new backing file");
goto out;
}
}
/* If they differ, we need to write to the COW file */
uint64_t written = 0;
while (written < n) {
int pnum;
if (compare_sectors(buf_old + written * 512,
buf_new + written * 512, n - written, &pnum))
{
ret = bdrv_write(bs, sector + written,
buf_old + written * 512, pnum);
if (ret < 0) {
error_report("Error while writing to COW image: %s",
strerror(-ret));
goto out;
}
}
written += pnum;
}
qemu_progress_print(local_progress, 100);
}
qemu_vfree(buf_old);
qemu_vfree(buf_new);
}
/*
* Change the backing file. All clusters that are different from the old
* backing file are overwritten in the COW file now, so the visible content
* doesn't change when we switch the backing file.
*/
ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
if (ret == -ENOSPC) {
error_report("Could not change the backing file to '%s': No "
"space left in the file header", out_baseimg);
} else if (ret < 0) {
error_report("Could not change the backing file to '%s': %s",
out_baseimg, strerror(-ret));
}
qemu_progress_print(100, 0);
/*
* TODO At this point it is possible to check if any clusters that are
* allocated in the COW file are the same in the backing file. If so, they
* could be dropped from the COW file. Don't do this before switching the
* backing file, in case of a crash this would lead to corruption.
*/
out:
qemu_progress_end();
/* Cleanup */
if (!unsafe) {
if (bs_old_backing != NULL) {
bdrv_delete(bs_old_backing);
}
if (bs_new_backing != NULL) {
bdrv_delete(bs_new_backing);
}
}
bdrv_delete(bs);
if (ret) {
return 1;
}
return 0;
}
static int img_resize(int argc, char **argv)
{
int c, ret, relative;
const char *filename, *fmt, *size;
int64_t n, total_size;
BlockDriverState *bs = NULL;
QEMUOptionParameter *param;
QEMUOptionParameter resize_options[] = {
{
.name = BLOCK_OPT_SIZE,
.type = OPT_SIZE,
.help = "Virtual disk size"
},
{ NULL }
};
/* Remove size from argv manually so that negative numbers are not treated
* as options by getopt. */
if (argc < 3) {
help();
return 1;
}
size = argv[--argc];
/* Parse getopt arguments */
fmt = NULL;
for(;;) {
c = getopt(argc, argv, "f:h");
if (c == -1) {
break;
}
switch(c) {
case '?':
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc) {
help();
}
filename = argv[optind++];
/* Choose grow, shrink, or absolute resize mode */
switch (size[0]) {
case '+':
relative = 1;
size++;
break;
case '-':
relative = -1;
size++;
break;
default:
relative = 0;
break;
}
/* Parse size */
param = parse_option_parameters("", resize_options, NULL);
if (set_option_parameter(param, BLOCK_OPT_SIZE, size)) {
/* Error message already printed when size parsing fails */
ret = -1;
goto out;
}
n = get_option_parameter(param, BLOCK_OPT_SIZE)->value.n;
free_option_parameters(param);
bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR);
if (!bs) {
ret = -1;
goto out;
}
if (relative) {
total_size = bdrv_getlength(bs) + n * relative;
} else {
total_size = n;
}
if (total_size <= 0) {
error_report("New image size must be positive");
ret = -1;
goto out;
}
ret = bdrv_truncate(bs, total_size);
switch (ret) {
case 0:
printf("Image resized.\n");
break;
case -ENOTSUP:
error_report("This image format does not support resize");
break;
case -EACCES:
error_report("Image is read-only");
break;
default:
error_report("Error resizing image (%d)", -ret);
break;
}
out:
if (bs) {
bdrv_delete(bs);
}
if (ret) {
return 1;
}
return 0;
}
static const img_cmd_t img_cmds[] = {
#define DEF(option, callback, arg_string) \
{ option, callback },
#include "qemu-img-cmds.h"
#undef DEF
#undef GEN_DOCS
{ NULL, NULL, },
};
int main(int argc, char **argv)
{
const img_cmd_t *cmd;
const char *cmdname;
error_set_progname(argv[0]);
bdrv_init();
if (argc < 2)
help();
cmdname = argv[1];
argc--; argv++;
/* find the command */
for(cmd = img_cmds; cmd->name != NULL; cmd++) {
if (!strcmp(cmdname, cmd->name)) {
return cmd->handler(argc, argv);
}
}
/* not found */
help();
return 0;
}
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