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qemu-e2k/qemu-img.c
aurel32 137519ce2e qemu-img: open files with cache=writeback 
Data integrity is not important in qemu-img, so open the files with
cache=writeback. This fixes the performance regression seen with qemu-img
since revision 5485, and most particularly with the qcow2 format.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5839 c046a42c-6fe2-441c-8c8c-71466251a162
2008-11-30 19:12:49 +00:00

757 lines
22 KiB
C
Raw Blame History

/*
* 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 "block_int.h"
#include <assert.h>
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif
/* Default to cache=writeback as data integrity is not important for qemu-tcg. */
#define BRDV_O_FLAGS BDRV_O_CACHE_WB
static void __attribute__((noreturn)) error(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "qemu-img: ");
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
exit(1);
va_end(ap);
}
static void format_print(void *opaque, const char *name)
{
printf(" %s", name);
}
static void help(void)
{
printf("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"
" create [-e] [-6] [-b base_image] [-f fmt] filename [size]\n"
" commit [-f fmt] filename\n"
" convert [-c] [-e] [-6] [-f fmt] [-O output_fmt] [-B output_base_image] filename [filename2 [...]] output_filename\n"
" info [-f fmt] filename\n"
"\n"
"Command parameters:\n"
" 'filename' is a disk image filename\n"
" 'base_image' is the read-only disk image which is used as base for a copy on\n"
" write image; the copy on write image only stores the modified data\n"
" 'output_base_image' forces the output image to be created as a copy on write\n"
" image of the specified base image; 'output_base_image' should have the same\n"
" content as the input's base image, however the path, image format, etc may\n"
" differ\n"
" 'fmt' is the disk image format. It is guessed automatically in most cases\n"
" 'size' is the disk image size in kilobytes. Optional suffixes 'M' (megabyte)\n"
" and 'G' (gigabyte) are supported\n"
" 'output_filename' is the destination disk image filename\n"
" 'output_fmt' is the destination format\n"
" '-c' indicates that target image must be compressed (qcow format only)\n"
" '-e' indicates that the target image must be encrypted (qcow format only)\n"
" '-6' indicates that the target image must use compatibility level 6 (vmdk format only)\n"
);
printf("\nSupported format:");
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 BlockDriverState *bdrv_new_open(const char *filename,
const char *fmt)
{
BlockDriverState *bs;
BlockDriver *drv;
char password[256];
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
if (bdrv_is_encrypted(bs)) {
printf("Disk image '%s' is encrypted.\n", filename);
if (read_password(password, sizeof(password)) < 0)
error("No password given");
if (bdrv_set_key(bs, password) < 0)
error("invalid password");
}
return bs;
}
static int img_create(int argc, char **argv)
{
int c, ret, flags;
const char *fmt = "raw";
const char *filename;
const char *base_filename = NULL;
uint64_t size;
const char *p;
BlockDriver *drv;
flags = 0;
for(;;) {
c = getopt(argc, argv, "b:f:he6");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'b':
base_filename = optarg;
break;
case 'f':
fmt = optarg;
break;
case 'e':
flags |= BLOCK_FLAG_ENCRYPT;
break;
case '6':
flags |= BLOCK_FLAG_COMPAT6;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
size = 0;
if (base_filename) {
BlockDriverState *bs;
bs = bdrv_new_open(base_filename, NULL);
bdrv_get_geometry(bs, &size);
size *= 512;
bdrv_delete(bs);
} else {
if (optind >= argc)
help();
p = argv[optind];
size = strtoul(p, (char **)&p, 0);
if (*p == 'M') {
size *= 1024 * 1024;
} else if (*p == 'G') {
size *= 1024 * 1024 * 1024;
} else if (*p == 'k' || *p == 'K' || *p == '\0') {
size *= 1024;
} else {
help();
}
}
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
printf("Formatting '%s', fmt=%s",
filename, fmt);
if (flags & BLOCK_FLAG_ENCRYPT)
printf(", encrypted");
if (flags & BLOCK_FLAG_COMPAT6)
printf(", compatibility level=6");
if (base_filename) {
printf(", backing_file=%s",
base_filename);
}
printf(", size=%" PRIu64 " kB\n", size / 1024);
ret = bdrv_create(drv, filename, size / 512, base_filename, flags);
if (ret < 0) {
if (ret == -ENOTSUP) {
error("Formatting or formatting option not supported for file format '%s'", fmt);
} else {
error("Error while formatting");
}
}
return 0;
}
static int img_commit(int argc, char **argv)
{
int c, ret;
const char *filename, *fmt;
BlockDriver *drv;
BlockDriverState *bs;
fmt = NULL;
for(;;) {
c = getopt(argc, argv, "f:h");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
ret = bdrv_commit(bs);
switch(ret) {
case 0:
printf("Image committed.\n");
break;
case -ENOENT:
error("No disk inserted");
break;
case -EACCES:
error("Image is read-only");
break;
case -ENOTSUP:
error("Image is already committed");
break;
default:
error("Error while committing image");
break;
}
bdrv_delete(bs);
return 0;
}
static int is_not_zero(const uint8_t *sector, int len)
{
int i;
len >>= 2;
for(i = 0;i < len; i++) {
if (((uint32_t *)sector)[i] != 0)
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;
}
#define IO_BUF_SIZE 65536
static int img_convert(int argc, char **argv)
{
int c, ret, n, n1, bs_n, bs_i, flags, cluster_size, cluster_sectors;
const char *fmt, *out_fmt, *out_baseimg, *out_filename;
BlockDriver *drv;
BlockDriverState **bs, *out_bs;
int64_t total_sectors, nb_sectors, sector_num, bs_offset;
uint64_t bs_sectors;
uint8_t buf[IO_BUF_SIZE];
const uint8_t *buf1;
BlockDriverInfo bdi;
fmt = NULL;
out_fmt = "raw";
out_baseimg = NULL;
flags = 0;
for(;;) {
c = getopt(argc, argv, "f:O:B:hce6");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
case 'O':
out_fmt = optarg;
break;
case 'B':
out_baseimg = optarg;
break;
case 'c':
flags |= BLOCK_FLAG_COMPRESS;
break;
case 'e':
flags |= BLOCK_FLAG_ENCRYPT;
break;
case '6':
flags |= BLOCK_FLAG_COMPAT6;
break;
}
}
bs_n = argc - optind - 1;
if (bs_n < 1) help();
out_filename = argv[argc - 1];
if (bs_n > 1 && out_baseimg)
error("-B makes no sense when concatenating multiple input images");
bs = calloc(bs_n, sizeof(BlockDriverState *));
if (!bs)
error("Out of memory");
total_sectors = 0;
for (bs_i = 0; bs_i < bs_n; bs_i++) {
bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt);
if (!bs[bs_i])
error("Could not open '%s'", argv[optind + bs_i]);
bdrv_get_geometry(bs[bs_i], &bs_sectors);
total_sectors += bs_sectors;
}
drv = bdrv_find_format(out_fmt);
if (!drv)
error("Unknown file format '%s'", out_fmt);
if (flags & BLOCK_FLAG_COMPRESS && drv != &bdrv_qcow && drv != &bdrv_qcow2)
error("Compression not supported for this file format");
if (flags & BLOCK_FLAG_ENCRYPT && drv != &bdrv_qcow && drv != &bdrv_qcow2)
error("Encryption not supported for this file format");
if (flags & BLOCK_FLAG_COMPAT6 && drv != &bdrv_vmdk)
error("Alternative compatibility level not supported for this file format");
if (flags & BLOCK_FLAG_ENCRYPT && flags & BLOCK_FLAG_COMPRESS)
error("Compression and encryption not supported at the same time");
ret = bdrv_create(drv, out_filename, total_sectors, out_baseimg, flags);
if (ret < 0) {
if (ret == -ENOTSUP) {
error("Formatting not supported for file format '%s'", fmt);
} else {
error("Error while formatting '%s'", out_filename);
}
}
out_bs = bdrv_new_open(out_filename, out_fmt);
bs_i = 0;
bs_offset = 0;
bdrv_get_geometry(bs[0], &bs_sectors);
if (flags & BLOCK_FLAG_COMPRESS) {
if (bdrv_get_info(out_bs, &bdi) < 0)
error("could not get block driver info");
cluster_size = bdi.cluster_size;
if (cluster_size <= 0 || cluster_size > IO_BUF_SIZE)
error("invalid cluster size");
cluster_sectors = cluster_size >> 9;
sector_num = 0;
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=%lld, "
"bs_i=%d, bs_offset=%lld, bs_sectors=%lld\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;
if (bdrv_read(bs[bs_i], bs_num, buf2, nlow) < 0)
error("error while reading");
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)) {
if (bdrv_write_compressed(out_bs, sector_num, buf,
cluster_sectors) != 0)
error("error while compressing sector %" PRId64,
sector_num);
}
sector_num += n;
}
/* signal EOF to align */
bdrv_write_compressed(out_bs, 0, NULL, 0);
} else {
sector_num = 0; // total number of sectors converted so far
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=%lld, bs_i=%d, "
"bs_offset=%lld, bs_sectors=%lld\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 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;
}
if (bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n) < 0)
error("error while reading");
/* 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 (out_baseimg || is_allocated_sectors(buf1, n, &n1)) {
if (bdrv_write(out_bs, sector_num, buf1, n1) < 0)
error("error while writing");
}
sector_num += n1;
n -= n1;
buf1 += n1 * 512;
}
}
}
bdrv_delete(out_bs);
for (bs_i = 0; bs_i < bs_n; bs_i++)
bdrv_delete(bs[bs_i]);
free(bs);
return 0;
}
#ifdef _WIN32
static int64_t get_allocated_file_size(const char *filename)
{
typedef DWORD (WINAPI * get_compressed_t)(const char *filename, DWORD *high);
get_compressed_t get_compressed;
struct _stati64 st;
/* WinNT support GetCompressedFileSize to determine allocate size */
get_compressed = (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"), "GetCompressedFileSizeA");
if (get_compressed) {
DWORD high, low;
low = get_compressed(filename, &high);
if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR)
return (((int64_t) high) << 32) + low;
}
if (_stati64(filename, &st) < 0)
return -1;
return st.st_size;
}
#else
static int64_t get_allocated_file_size(const char *filename)
{
struct stat st;
if (stat(filename, &st) < 0)
return -1;
return (int64_t)st.st_blocks * 512;
}
#endif
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));
}
qemu_free(sn_tab);
}
static int img_info(int argc, char **argv)
{
int c;
const char *filename, *fmt;
BlockDriver *drv;
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 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
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 = get_allocated_file_size(filename);
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;
}
int main(int argc, char **argv)
{
const char *cmd;
bdrv_init();
if (argc < 2)
help();
cmd = argv[1];
optind++;
if (!strcmp(cmd, "create")) {
img_create(argc, argv);
} else if (!strcmp(cmd, "commit")) {
img_commit(argc, argv);
} else if (!strcmp(cmd, "convert")) {
img_convert(argc, argv);
} else if (!strcmp(cmd, "info")) {
img_info(argc, argv);
} else {
help();
}
return 0;
}
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