/* * 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 "osdep.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 BRDV_O_FLAGS BDRV_O_CACHE_WB static void QEMU_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); } /* Please keep in synch with qemu-img.texi */ 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" #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" " '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" "\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("\nSupported formats:"); 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 void add_old_style_options(const char *fmt, QEMUOptionParameter *list, int flags, const char *base_filename, const char *base_fmt) { if (flags & BLOCK_FLAG_ENCRYPT) { if (set_option_parameter(list, BLOCK_OPT_ENCRYPT, "on")) { error("Encryption not supported for file format '%s'", fmt); } } if (flags & BLOCK_FLAG_COMPAT6) { if (set_option_parameter(list, BLOCK_OPT_COMPAT6, "on")) { error("VMDK version 6 not supported for file format '%s'", fmt); } } if (base_filename) { if (set_option_parameter(list, BLOCK_OPT_BACKING_FILE, base_filename)) { error("Backing file not supported for file format '%s'", fmt); } } if (base_fmt) { if (set_option_parameter(list, BLOCK_OPT_BACKING_FMT, base_fmt)) { error("Backing file format not supported for file format '%s'", fmt); } } } static int img_create(int argc, char **argv) { int c, ret, flags; const char *fmt = "raw"; const char *base_fmt = NULL; const char *filename; const char *base_filename = NULL; BlockDriver *drv; QEMUOptionParameter *param = NULL; char *options = NULL; flags = 0; for(;;) { c = getopt(argc, argv, "F:b:f:he6o:"); if (c == -1) break; switch(c) { case 'h': help(); break; case 'F': base_fmt = optarg; 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; case 'o': options = optarg; break; } } /* Find driver and parse its options */ drv = bdrv_find_format(fmt); if (!drv) error("Unknown file format '%s'", fmt); if (options && !strcmp(options, "?")) { print_option_help(drv->create_options); return 0; } /* Create parameter list with default values */ param = parse_option_parameters("", drv->create_options, param); set_option_parameter_int(param, BLOCK_OPT_SIZE, -1); /* Parse -o options */ if (options) { param = parse_option_parameters(options, drv->create_options, param); if (param == NULL) { error("Invalid options for file format '%s'.", fmt); } } /* Get the filename */ if (optind >= argc) help(); filename = argv[optind++]; /* Add size to parameters */ if (optind < argc) { set_option_parameter(param, BLOCK_OPT_SIZE, argv[optind++]); } /* Add old-style options to parameters */ add_old_style_options(fmt, param, flags, base_filename, base_fmt); // The size for the image must always be specified, with one exception: // If we are using a backing file, we can obtain the size from there if (get_option_parameter(param, BLOCK_OPT_SIZE)->value.n == -1) { QEMUOptionParameter *backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE); QEMUOptionParameter *backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT); if (backing_file && backing_file->value.s) { BlockDriverState *bs; uint64_t size; const char *fmt = NULL; char buf[32]; if (backing_fmt && backing_fmt->value.s) { if (bdrv_find_format(backing_fmt->value.s)) { fmt = backing_fmt->value.s; } else { error("Unknown backing file format '%s'", backing_fmt->value.s); } } bs = bdrv_new_open(backing_file->value.s, fmt); bdrv_get_geometry(bs, &size); size *= 512; bdrv_delete(bs); snprintf(buf, sizeof(buf), "%" PRId64, size); set_option_parameter(param, BLOCK_OPT_SIZE, buf); } else { error("Image creation needs a size parameter"); } } printf("Formatting '%s', fmt=%s ", filename, fmt); print_option_parameters(param); puts(""); ret = bdrv_create(drv, filename, param); free_option_parameters(param); if (ret < 0) { if (ret == -ENOTSUP) { error("Formatting or formatting option not supported for file format '%s'", fmt); } else if (ret == -EFBIG) { error("The image size is too large for file format '%s'", fmt); } else { error("Error while formatting"); } } return 0; } static int img_check(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_check(bs); switch(ret) { case 0: printf("No errors were found on the image.\n"); break; case -ENOTSUP: error("This image format does not support checks"); break; default: if (ret < 0) { error("An error occurred during the check"); } else { printf("%d errors were found on the image.\n", ret); } break; } bdrv_delete(bs); 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; } /* * 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, 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; QEMUOptionParameter *param = NULL; char *options = NULL; fmt = NULL; out_fmt = "raw"; out_baseimg = NULL; flags = 0; for(;;) { c = getopt(argc, argv, "f:O:B:hce6o:"); 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; case 'o': options = optarg; 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; } /* Find driver and parse its options */ drv = bdrv_find_format(out_fmt); if (!drv) error("Unknown file format '%s'", out_fmt); if (options && !strcmp(options, "?")) { print_option_help(drv->create_options); free(bs); return 0; } if (options) { param = parse_option_parameters(options, drv->create_options, param); if (param == NULL) { error("Invalid options for file format '%s'.", out_fmt); } } else { param = parse_option_parameters("", drv->create_options, param); } set_option_parameter_int(param, BLOCK_OPT_SIZE, total_sectors * 512); add_old_style_options(out_fmt, param, flags, out_baseimg, NULL); /* Check if compression is supported */ if (flags & BLOCK_FLAG_COMPRESS) { QEMUOptionParameter *encryption = get_option_parameter(param, BLOCK_OPT_ENCRYPT); if (!drv->bdrv_write_compressed) { error("Compression not supported for this file format"); } if (encryption && encryption->value.n) { error("Compression and encryption not supported at the same time"); } } /* Create the new image */ ret = bdrv_create(drv, out_filename, param); free_option_parameters(param); if (ret < 0) { if (ret == -ENOTSUP) { error("Formatting not supported for file format '%s'", out_fmt); } else if (ret == -EFBIG) { error("The image size is too large for file format '%s'", out_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 (!drv->no_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; } 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 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 (drv->no_zero_init || 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 | BDRV_O_NO_BACKING, 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; } #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; int action = 0; qemu_timeval tv; /* Parse commandline parameters */ for(;;) { c = getopt(argc, argv, "la:c:d:h"); if (c == -1) break; switch(c) { case 'h': help(); return 0; case 'l': if (action) { help(); return 0; } action = SNAPSHOT_LIST; 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(""); if (!bs) error("Not enough memory"); if (bdrv_open2(bs, filename, 0, NULL) < 0) { error("Could not open '%s'", filename); } /* 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("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("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("Could not delete snapshot '%s': %d (%s)", snapshot_name, ret, strerror(-ret)); break; } /* Cleanup */ bdrv_delete(bs); return 0; } static int img_rebase(int argc, char **argv) { BlockDriverState *bs, *bs_old_backing, *bs_new_backing; BlockDriver *old_backing_drv, *new_backing_drv; char *filename; const char *out_basefmt, *out_baseimg; int c, flags, ret; int unsafe = 0; /* Parse commandline parameters */ out_baseimg = NULL; out_basefmt = NULL; for(;;) { c = getopt(argc, argv, "uhF:b:"); if (c == -1) break; switch(c) { case 'h': help(); return 0; case 'F': out_basefmt = optarg; break; case 'b': out_baseimg = optarg; break; case 'u': unsafe = 1; break; } } if ((optind >= argc) || !out_baseimg) help(); filename = argv[optind++]; /* * 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(""); if (!bs) error("Not enough memory"); flags = BRDV_O_FLAGS | (unsafe ? BDRV_O_NO_BACKING : 0); if (bdrv_open2(bs, filename, flags, NULL) < 0) { error("Could not open '%s'", filename); } /* 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("Invalid format name: '%s'", bs->backing_format); } } if (out_basefmt != NULL) { new_backing_drv = bdrv_find_format(out_basefmt); if (new_backing_drv == NULL) { error("Invalid format name: '%s'", out_basefmt); } } /* 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)); if (bdrv_open2(bs_old_backing, backing_name, BRDV_O_FLAGS, old_backing_drv)) { error("Could not open old backing file '%s'", backing_name); return -1; } bs_new_backing = bdrv_new("new_backing"); if (bdrv_open2(bs_new_backing, out_baseimg, BRDV_O_FLAGS, new_backing_drv)) { error("Could not open new backing file '%s'", backing_name); return -1; } } /* * 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 sector; int n, n1; uint8_t buf_old[IO_BUF_SIZE]; uint8_t buf_new[IO_BUF_SIZE]; bdrv_get_geometry(bs, &num_sectors); 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 */ if (bdrv_is_allocated(bs, sector, n, &n1)) { n = n1; continue; } /* Read old and new backing file */ if (bdrv_read(bs_old_backing, sector, buf_old, n) < 0) { error("error while reading from old backing file"); } if (bdrv_read(bs_new_backing, sector, buf_new, n) < 0) { error("error while reading from new backing file"); } /* 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, &pnum)) { ret = bdrv_write(bs, sector + written, buf_old + written * 512, pnum); if (ret < 0) { error("Error while writing to COW image: %s", strerror(-ret)); } } written += pnum; } } } /* * 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("Could not change the backing file to '%s': No space left in " "the file header", out_baseimg); } else if (ret < 0) { error("Could not change the backing file to '%s': %s", out_baseimg, strerror(-ret)); } /* * 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. */ /* Cleanup */ if (!unsafe) { bdrv_delete(bs_old_backing); bdrv_delete(bs_new_backing); } bdrv_delete(bs); 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; 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; }