diff options
| -rw-r--r-- | qemu-img-cmds.hx | 6 | ||||
| -rw-r--r-- | qemu-img.c | 290 | ||||
| -rw-r--r-- | qemu-img.texi | 53 |
3 files changed, 348 insertions, 1 deletions
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index 92837765b9..4ca7e95655 100644 --- a/qemu-img-cmds.hx +++ b/qemu-img-cmds.hx @@ -27,6 +27,12 @@ STEXI @item commit [-q] [-f @var{fmt}] [-t @var{cache}] @var{filename} ETEXI +DEF("compare", img_compare, + "compare [-f fmt] [-F fmt] [-p] [-q] [-s] filename1 filename2") +STEXI +@item compare [-f @var{fmt}] [-F @var{fmt}] [-p] [-q] [-s] @var{filename1} @var{filename2} +ETEXI + DEF("convert", img_convert, "convert [-c] [-p] [-q] [-f fmt] [-t cache] [-O output_fmt] [-o options] [-s snapshot_name] [-S sparse_size] filename [filename2 [...]] output_filename") STEXI diff --git a/qemu-img.c b/qemu-img.c index 3e2996e3c3..471de7d646 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -113,7 +113,12 @@ static void help(void) " '-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"; + " '-l' lists all snapshots in the given image\n" + "\n" + "Parameters to compare subcommand:\n" + " '-f' first image format\n" + " '-F' second image format\n" + " '-s' run in Strict mode - fail on different image size or sector allocation\n"; printf("%s\nSupported formats:", help_msg); bdrv_iterate_format(format_print, NULL); @@ -820,6 +825,289 @@ static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n, #define IO_BUF_SIZE (2 * 1024 * 1024) +static int64_t sectors_to_bytes(int64_t sectors) +{ + return sectors << BDRV_SECTOR_BITS; +} + +static int64_t sectors_to_process(int64_t total, int64_t from) +{ + return MIN(total - from, IO_BUF_SIZE >> BDRV_SECTOR_BITS); +} + +/* + * Check if passed sectors are empty (not allocated or contain only 0 bytes) + * + * Returns 0 in case sectors are filled with 0, 1 if sectors contain non-zero + * data and negative value on error. + * + * @param bs: Driver used for accessing file + * @param sect_num: Number of first sector to check + * @param sect_count: Number of sectors to check + * @param filename: Name of disk file we are checking (logging purpose) + * @param buffer: Allocated buffer for storing read data + * @param quiet: Flag for quiet mode + */ +static int check_empty_sectors(BlockDriverState *bs, int64_t sect_num, + int sect_count, const char *filename, + uint8_t *buffer, bool quiet) +{ + int pnum, ret = 0; + ret = bdrv_read(bs, sect_num, buffer, sect_count); + if (ret < 0) { + error_report("Error while reading offset %" PRId64 " of %s: %s", + sectors_to_bytes(sect_num), filename, strerror(-ret)); + return ret; + } + ret = is_allocated_sectors(buffer, sect_count, &pnum); + if (ret || pnum != sect_count) { + qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n", + sectors_to_bytes(ret ? sect_num : sect_num + pnum)); + return 1; + } + + return 0; +} + +/* + * Compares two images. Exit codes: + * + * 0 - Images are identical + * 1 - Images differ + * >1 - Error occurred + */ +static int img_compare(int argc, char **argv) +{ + const char *fmt1 = NULL, *fmt2 = NULL, *filename1, *filename2; + BlockDriverState *bs1, *bs2; + int64_t total_sectors1, total_sectors2; + uint8_t *buf1 = NULL, *buf2 = NULL; + int pnum1, pnum2; + int allocated1, allocated2; + int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */ + bool progress = false, quiet = false, strict = false; + int64_t total_sectors; + int64_t sector_num = 0; + int64_t nb_sectors; + int c, pnum; + uint64_t bs_sectors; + uint64_t progress_base; + + for (;;) { + c = getopt(argc, argv, "hpf:F:sq"); + if (c == -1) { + break; + } + switch (c) { + case '?': + case 'h': + help(); + break; + case 'f': + fmt1 = optarg; + break; + case 'F': + fmt2 = optarg; + break; + case 'p': + progress = true; + break; + case 'q': + quiet = true; + break; + case 's': + strict = true; + break; + } + } + + /* Progress is not shown in Quiet mode */ + if (quiet) { + progress = false; + } + + + if (optind > argc - 2) { + help(); + } + filename1 = argv[optind++]; + filename2 = argv[optind++]; + + /* Initialize before goto out */ + qemu_progress_init(progress, 2.0); + + bs1 = bdrv_new_open(filename1, fmt1, BDRV_O_FLAGS, true, quiet); + if (!bs1) { + error_report("Can't open file %s", filename1); + ret = 2; + goto out3; + } + + bs2 = bdrv_new_open(filename2, fmt2, BDRV_O_FLAGS, true, quiet); + if (!bs2) { + error_report("Can't open file %s", filename2); + ret = 2; + goto out2; + } + + buf1 = qemu_blockalign(bs1, IO_BUF_SIZE); + buf2 = qemu_blockalign(bs2, IO_BUF_SIZE); + bdrv_get_geometry(bs1, &bs_sectors); + total_sectors1 = bs_sectors; + bdrv_get_geometry(bs2, &bs_sectors); + total_sectors2 = bs_sectors; + total_sectors = MIN(total_sectors1, total_sectors2); + progress_base = MAX(total_sectors1, total_sectors2); + + qemu_progress_print(0, 100); + + if (strict && total_sectors1 != total_sectors2) { + ret = 1; + qprintf(quiet, "Strict mode: Image size mismatch!\n"); + goto out; + } + + for (;;) { + nb_sectors = sectors_to_process(total_sectors, sector_num); + if (nb_sectors <= 0) { + break; + } + allocated1 = bdrv_is_allocated_above(bs1, NULL, sector_num, nb_sectors, + &pnum1); + if (allocated1 < 0) { + ret = 3; + error_report("Sector allocation test failed for %s", filename1); + goto out; + } + + allocated2 = bdrv_is_allocated_above(bs2, NULL, sector_num, nb_sectors, + &pnum2); + if (allocated2 < 0) { + ret = 3; + error_report("Sector allocation test failed for %s", filename2); + goto out; + } + nb_sectors = MIN(pnum1, pnum2); + + if (allocated1 == allocated2) { + if (allocated1) { + ret = bdrv_read(bs1, sector_num, buf1, nb_sectors); + if (ret < 0) { + error_report("Error while reading offset %" PRId64 " of %s:" + " %s", sectors_to_bytes(sector_num), filename1, + strerror(-ret)); + ret = 4; + goto out; + } + ret = bdrv_read(bs2, sector_num, buf2, nb_sectors); + if (ret < 0) { + error_report("Error while reading offset %" PRId64 + " of %s: %s", sectors_to_bytes(sector_num), + filename2, strerror(-ret)); + ret = 4; + goto out; + } + ret = compare_sectors(buf1, buf2, nb_sectors, &pnum); + if (ret || pnum != nb_sectors) { + ret = 1; + qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n", + sectors_to_bytes( + ret ? sector_num : sector_num + pnum)); + goto out; + } + } + } else { + if (strict) { + ret = 1; + qprintf(quiet, "Strict mode: Offset %" PRId64 + " allocation mismatch!\n", + sectors_to_bytes(sector_num)); + goto out; + } + + if (allocated1) { + ret = check_empty_sectors(bs1, sector_num, nb_sectors, + filename1, buf1, quiet); + } else { + ret = check_empty_sectors(bs2, sector_num, nb_sectors, + filename2, buf1, quiet); + } + if (ret) { + if (ret < 0) { + ret = 4; + error_report("Error while reading offset %" PRId64 ": %s", + sectors_to_bytes(sector_num), strerror(-ret)); + } + goto out; + } + } + sector_num += nb_sectors; + qemu_progress_print(((float) nb_sectors / progress_base)*100, 100); + } + + if (total_sectors1 != total_sectors2) { + BlockDriverState *bs_over; + int64_t total_sectors_over; + const char *filename_over; + + qprintf(quiet, "Warning: Image size mismatch!\n"); + if (total_sectors1 > total_sectors2) { + total_sectors_over = total_sectors1; + bs_over = bs1; + filename_over = filename1; + } else { + total_sectors_over = total_sectors2; + bs_over = bs2; + filename_over = filename2; + } + + for (;;) { + nb_sectors = sectors_to_process(total_sectors_over, sector_num); + if (nb_sectors <= 0) { + break; + } + ret = bdrv_is_allocated_above(bs_over, NULL, sector_num, + nb_sectors, &pnum); + if (ret < 0) { + ret = 3; + error_report("Sector allocation test failed for %s", + filename_over); + goto out; + + } + nb_sectors = pnum; + if (ret) { + ret = check_empty_sectors(bs_over, sector_num, nb_sectors, + filename_over, buf1, quiet); + if (ret) { + if (ret < 0) { + ret = 4; + error_report("Error while reading offset %" PRId64 + " of %s: %s", sectors_to_bytes(sector_num), + filename_over, strerror(-ret)); + } + goto out; + } + } + sector_num += nb_sectors; + qemu_progress_print(((float) nb_sectors / progress_base)*100, 100); + } + } + + qprintf(quiet, "Images are identical.\n"); + ret = 0; + +out: + bdrv_delete(bs2); + qemu_vfree(buf1); + qemu_vfree(buf2); +out2: + bdrv_delete(bs1); +out3: + qemu_progress_end(); + return ret; +} + static int img_convert(int argc, char **argv) { int c, ret = 0, n, n1, bs_n, bs_i, compress, cluster_size, cluster_sectors; diff --git a/qemu-img.texi b/qemu-img.texi index 43430fbea1..69f1bda6ae 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -84,6 +84,18 @@ deletes a snapshot lists all snapshots in the given image @end table +Parameters to compare subcommand: + +@table @option + +@item -f +First image format +@item -F +Second image format +@item -s +Strict mode - fail on on different image size or sector allocation +@end table + Command description: @table @option @@ -118,6 +130,47 @@ it doesn't need to be specified separately in this case. Commit the changes recorded in @var{filename} in its base image. +@item compare [-f @var{fmt}] [-F @var{fmt}] [-p] [-s] [-q] @var{filename1} @var{filename2} + +Check if two images have the same content. You can compare images with +different format or settings. + +The format is probed unless you specify it by @var{-f} (used for +@var{filename1}) and/or @var{-F} (used for @var{filename2}) option. + +By default, images with different size are considered identical if the larger +image contains only unallocated and/or zeroed sectors in the area after the end +of the other image. In addition, if any sector is not allocated in one image +and contains only zero bytes in the second one, it is evaluated as equal. You +can use Strict mode by specifying the @var{-s} option. When compare runs in +Strict mode, it fails in case image size differs or a sector is allocated in +one image and is not allocated in the second one. + +By default, compare prints out a result message. This message displays +information that both images are same or the position of the first different +byte. In addition, result message can report different image size in case +Strict mode is used. + +Compare exits with @code{0} in case the images are equal and with @code{1} +in case the images differ. Other exit codes mean an error occurred during +execution and standard error output should contain an error message. +The following table sumarizes all exit codes of the compare subcommand: + +@table @option + +@item 0 +Images are identical +@item 1 +Images differ +@item 2 +Error on opening an image +@item 3 +Error on checking a sector allocation +@item 4 +Error on reading data + +@end table + @item convert [-c] [-p] [-f @var{fmt}] [-t @var{cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_name}] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename} Convert the disk image @var{filename} or a snapshot @var{snapshot_name} to disk image @var{output_filename} |