diff options
Diffstat (limited to 'qemu-img.c')
| -rw-r--r-- | qemu-img.c | 381 |
1 files changed, 172 insertions, 209 deletions
diff --git a/qemu-img.c b/qemu-img.c index d6007b2a6d..02a6e27beb 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1065,6 +1065,28 @@ done: } /* + * Returns -1 if 'buf' contains only zeroes, otherwise the byte index + * of the first sector boundary within buf where the sector contains a + * non-zero byte. This function is robust to a buffer that is not + * sector-aligned. + */ +static int64_t find_nonzero(const uint8_t *buf, int64_t n) +{ + int64_t i; + int64_t end = QEMU_ALIGN_DOWN(n, BDRV_SECTOR_SIZE); + + for (i = 0; i < end; i += BDRV_SECTOR_SIZE) { + if (!buffer_is_zero(buf + i, BDRV_SECTOR_SIZE)) { + return i; + } + } + if (i < n && !buffer_is_zero(buf + i, n - end)) { + return i; + } + return -1; +} + +/* * Returns true iff the first sector pointed to by 'buf' contains at least * a non-NUL byte. * @@ -1134,31 +1156,28 @@ static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum, } /* - * Compares two buffers sector by sector. Returns 0 if the first sector of both - * buffers matches, non-zero otherwise. + * Compares two buffers sector by sector. Returns 0 if the first + * sector of each buffer 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 + * pnum is set to the sector-aligned size of the buffer prefix that + * has the same matching status as the first sector. */ -static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n, - int *pnum) +static int compare_buffers(const uint8_t *buf1, const uint8_t *buf2, + int64_t bytes, int64_t *pnum) { bool res; - int i; + int64_t i = MIN(bytes, BDRV_SECTOR_SIZE); - if (n <= 0) { - *pnum = 0; - return 0; - } + assert(bytes > 0); - res = !!memcmp(buf1, buf2, 512); - for(i = 1; i < n; i++) { - buf1 += 512; - buf2 += 512; + res = !!memcmp(buf1, buf2, i); + while (i < bytes) { + int64_t len = MIN(bytes - i, BDRV_SECTOR_SIZE); - if (!!memcmp(buf1, buf2, 512) != res) { + if (!!memcmp(buf1 + i, buf2 + i, len) != res) { break; } + i += len; } *pnum = i; @@ -1167,45 +1186,38 @@ 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. + * Intended for use by 'qemu-img compare': Returns 0 in case sectors are + * filled with 0, 1 if sectors contain non-zero data (this is a comparison + * failure), and 4 on error (the exit status for read errors), after emitting + * an error message. * * @param blk: BlockBackend for the image - * @param sect_num: Number of first sector to check - * @param sect_count: Number of sectors to check + * @param offset: Starting offset to check + * @param bytes: Number of bytes 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(BlockBackend *blk, int64_t sect_num, - int sect_count, const char *filename, +static int check_empty_sectors(BlockBackend *blk, int64_t offset, + int64_t bytes, const char *filename, uint8_t *buffer, bool quiet) { - int pnum, ret = 0; - ret = blk_pread(blk, sect_num << BDRV_SECTOR_BITS, buffer, - sect_count << BDRV_SECTOR_BITS); + int ret = 0; + int64_t idx; + + ret = blk_pread(blk, offset, buffer, bytes); if (ret < 0) { error_report("Error while reading offset %" PRId64 " of %s: %s", - sectors_to_bytes(sect_num), filename, strerror(-ret)); - return ret; + offset, filename, strerror(-ret)); + return 4; } - ret = is_allocated_sectors(buffer, sect_count, &pnum); - if (ret || pnum != sect_count) { + idx = find_nonzero(buffer, bytes); + if (idx >= 0) { qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n", - sectors_to_bytes(ret ? sect_num : sect_num + pnum)); + offset + idx); return 1; } @@ -1224,18 +1236,18 @@ static int img_compare(int argc, char **argv) const char *fmt1 = NULL, *fmt2 = NULL, *cache, *filename1, *filename2; BlockBackend *blk1, *blk2; BlockDriverState *bs1, *bs2; - int64_t total_sectors1, total_sectors2; + int64_t total_size1, total_size2; uint8_t *buf1 = NULL, *buf2 = NULL; - int pnum1, pnum2; + int64_t pnum1, pnum2; int allocated1, allocated2; int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */ bool progress = false, quiet = false, strict = false; int flags; bool writethrough; - int64_t total_sectors; - int64_t sector_num = 0; - int64_t nb_sectors; - int c, pnum; + int64_t total_size; + int64_t offset = 0; + int64_t chunk; + int c; uint64_t progress_base; bool image_opts = false; bool force_share = false; @@ -1348,42 +1360,37 @@ static int img_compare(int argc, char **argv) buf1 = blk_blockalign(blk1, IO_BUF_SIZE); buf2 = blk_blockalign(blk2, IO_BUF_SIZE); - total_sectors1 = blk_nb_sectors(blk1); - if (total_sectors1 < 0) { + total_size1 = blk_getlength(blk1); + if (total_size1 < 0) { error_report("Can't get size of %s: %s", - filename1, strerror(-total_sectors1)); + filename1, strerror(-total_size1)); ret = 4; goto out; } - total_sectors2 = blk_nb_sectors(blk2); - if (total_sectors2 < 0) { + total_size2 = blk_getlength(blk2); + if (total_size2 < 0) { error_report("Can't get size of %s: %s", - filename2, strerror(-total_sectors2)); + filename2, strerror(-total_size2)); ret = 4; goto out; } - total_sectors = MIN(total_sectors1, total_sectors2); - progress_base = MAX(total_sectors1, total_sectors2); + total_size = MIN(total_size1, total_size2); + progress_base = MAX(total_size1, total_size2); qemu_progress_print(0, 100); - if (strict && total_sectors1 != total_sectors2) { + if (strict && total_size1 != total_size2) { ret = 1; qprintf(quiet, "Strict mode: Image size mismatch!\n"); goto out; } - for (;;) { - int64_t status1, status2; - BlockDriverState *file; + while (offset < total_size) { + int status1, status2; - nb_sectors = sectors_to_process(total_sectors, sector_num); - if (nb_sectors <= 0) { - break; - } - status1 = bdrv_get_block_status_above(bs1, NULL, sector_num, - total_sectors1 - sector_num, - &pnum1, &file); + status1 = bdrv_block_status_above(bs1, NULL, offset, + total_size1 - offset, &pnum1, NULL, + NULL); if (status1 < 0) { ret = 3; error_report("Sector allocation test failed for %s", filename1); @@ -1391,112 +1398,92 @@ static int img_compare(int argc, char **argv) } allocated1 = status1 & BDRV_BLOCK_ALLOCATED; - status2 = bdrv_get_block_status_above(bs2, NULL, sector_num, - total_sectors2 - sector_num, - &pnum2, &file); + status2 = bdrv_block_status_above(bs2, NULL, offset, + total_size2 - offset, &pnum2, NULL, + NULL); if (status2 < 0) { ret = 3; error_report("Sector allocation test failed for %s", filename2); goto out; } allocated2 = status2 & BDRV_BLOCK_ALLOCATED; - if (pnum1) { - nb_sectors = MIN(nb_sectors, pnum1); - } - if (pnum2) { - nb_sectors = MIN(nb_sectors, pnum2); - } + + assert(pnum1 && pnum2); + chunk = MIN(pnum1, pnum2); if (strict) { - if ((status1 & ~BDRV_BLOCK_OFFSET_MASK) != - (status2 & ~BDRV_BLOCK_OFFSET_MASK)) { + if (status1 != status2) { ret = 1; qprintf(quiet, "Strict mode: Offset %" PRId64 - " block status mismatch!\n", - sectors_to_bytes(sector_num)); + " block status mismatch!\n", offset); goto out; } } if ((status1 & BDRV_BLOCK_ZERO) && (status2 & BDRV_BLOCK_ZERO)) { - nb_sectors = MIN(pnum1, pnum2); + /* nothing to do */ } else if (allocated1 == allocated2) { if (allocated1) { - ret = blk_pread(blk1, sector_num << BDRV_SECTOR_BITS, buf1, - nb_sectors << BDRV_SECTOR_BITS); + int64_t pnum; + + chunk = MIN(chunk, IO_BUF_SIZE); + ret = blk_pread(blk1, offset, buf1, chunk); if (ret < 0) { - error_report("Error while reading offset %" PRId64 " of %s:" - " %s", sectors_to_bytes(sector_num), filename1, - strerror(-ret)); + error_report("Error while reading offset %" PRId64 + " of %s: %s", + offset, filename1, strerror(-ret)); ret = 4; goto out; } - ret = blk_pread(blk2, sector_num << BDRV_SECTOR_BITS, buf2, - nb_sectors << BDRV_SECTOR_BITS); + ret = blk_pread(blk2, offset, buf2, chunk); if (ret < 0) { error_report("Error while reading offset %" PRId64 - " of %s: %s", sectors_to_bytes(sector_num), - filename2, strerror(-ret)); + " of %s: %s", + offset, filename2, strerror(-ret)); ret = 4; goto out; } - ret = compare_sectors(buf1, buf2, nb_sectors, &pnum); - if (ret || pnum != nb_sectors) { + ret = compare_buffers(buf1, buf2, chunk, &pnum); + if (ret || pnum != chunk) { qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n", - sectors_to_bytes( - ret ? sector_num : sector_num + pnum)); + offset + (ret ? 0 : pnum)); ret = 1; goto out; } } } else { - + chunk = MIN(chunk, IO_BUF_SIZE); if (allocated1) { - ret = check_empty_sectors(blk1, sector_num, nb_sectors, + ret = check_empty_sectors(blk1, offset, chunk, filename1, buf1, quiet); } else { - ret = check_empty_sectors(blk2, sector_num, nb_sectors, + ret = check_empty_sectors(blk2, offset, chunk, filename2, buf1, quiet); } if (ret) { - if (ret < 0) { - error_report("Error while reading offset %" PRId64 ": %s", - sectors_to_bytes(sector_num), strerror(-ret)); - ret = 4; - } goto out; } } - sector_num += nb_sectors; - qemu_progress_print(((float) nb_sectors / progress_base)*100, 100); + offset += chunk; + qemu_progress_print(((float) chunk / progress_base) * 100, 100); } - if (total_sectors1 != total_sectors2) { + if (total_size1 != total_size2) { BlockBackend *blk_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; + if (total_size1 > total_size2) { blk_over = blk1; filename_over = filename1; } else { - total_sectors_over = total_sectors2; blk_over = blk2; filename_over = filename2; } - for (;;) { - int64_t count; - - nb_sectors = sectors_to_process(total_sectors_over, sector_num); - if (nb_sectors <= 0) { - break; - } - ret = bdrv_is_allocated_above(blk_bs(blk_over), NULL, - sector_num * BDRV_SECTOR_SIZE, - nb_sectors * BDRV_SECTOR_SIZE, - &count); + while (offset < progress_base) { + ret = bdrv_block_status_above(blk_bs(blk_over), NULL, offset, + progress_base - offset, &chunk, + NULL, NULL); if (ret < 0) { ret = 3; error_report("Sector allocation test failed for %s", @@ -1504,25 +1491,16 @@ static int img_compare(int argc, char **argv) goto out; } - /* TODO relax this once bdrv_is_allocated_above does not enforce - * sector alignment */ - assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)); - nb_sectors = count >> BDRV_SECTOR_BITS; - if (ret) { - ret = check_empty_sectors(blk_over, sector_num, nb_sectors, + if (ret & BDRV_BLOCK_ALLOCATED && !(ret & BDRV_BLOCK_ZERO)) { + chunk = MIN(chunk, IO_BUF_SIZE); + ret = check_empty_sectors(blk_over, offset, chunk, filename_over, buf1, quiet); if (ret) { - if (ret < 0) { - error_report("Error while reading offset %" PRId64 - " of %s: %s", sectors_to_bytes(sector_num), - filename_over, strerror(-ret)); - ret = 4; - } goto out; } } - sector_num += nb_sectors; - qemu_progress_print(((float) nb_sectors / progress_base)*100, 100); + offset += chunk; + qemu_progress_print(((float) chunk / progress_base) * 100, 100); } } @@ -1590,8 +1568,8 @@ static void convert_select_part(ImgConvertState *s, int64_t sector_num, static int convert_iteration_sectors(ImgConvertState *s, int64_t sector_num) { - int64_t ret, src_cur_offset; - int n, src_cur; + int64_t src_cur_offset; + int ret, n, src_cur; convert_select_part(s, sector_num, &src_cur, &src_cur_offset); @@ -1599,19 +1577,24 @@ static int convert_iteration_sectors(ImgConvertState *s, int64_t sector_num) n = MIN(s->total_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS); if (s->sector_next_status <= sector_num) { - BlockDriverState *file; + int64_t count = n * BDRV_SECTOR_SIZE; + if (s->target_has_backing) { - ret = bdrv_get_block_status(blk_bs(s->src[src_cur]), - sector_num - src_cur_offset, - n, &n, &file); + + ret = bdrv_block_status(blk_bs(s->src[src_cur]), + (sector_num - src_cur_offset) * + BDRV_SECTOR_SIZE, + count, &count, NULL, NULL); } else { - ret = bdrv_get_block_status_above(blk_bs(s->src[src_cur]), NULL, - sector_num - src_cur_offset, - n, &n, &file); + ret = bdrv_block_status_above(blk_bs(s->src[src_cur]), NULL, + (sector_num - src_cur_offset) * + BDRV_SECTOR_SIZE, + count, &count, NULL, NULL); } if (ret < 0) { return ret; } + n = DIV_ROUND_UP(count, BDRV_SECTOR_SIZE); if (ret & BDRV_BLOCK_ZERO) { s->status = BLK_ZERO; @@ -2673,13 +2656,14 @@ static void dump_map_entry(OutputFormat output_format, MapEntry *e, } } -static int get_block_status(BlockDriverState *bs, int64_t sector_num, - int nb_sectors, MapEntry *e) +static int get_block_status(BlockDriverState *bs, int64_t offset, + int64_t bytes, MapEntry *e) { - int64_t ret; + int ret; int depth; BlockDriverState *file; bool has_offset; + int64_t map; /* As an optimization, we could cache the current range of unallocated * clusters in each file of the chain, and avoid querying the same @@ -2688,12 +2672,11 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, depth = 0; for (;;) { - ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors, - &file); + ret = bdrv_block_status(bs, offset, bytes, &bytes, &map, &file); if (ret < 0) { return ret; } - assert(nb_sectors); + assert(bytes); if (ret & (BDRV_BLOCK_ZERO|BDRV_BLOCK_DATA)) { break; } @@ -2709,11 +2692,11 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID); *e = (MapEntry) { - .start = sector_num * BDRV_SECTOR_SIZE, - .length = nb_sectors * BDRV_SECTOR_SIZE, + .start = offset, + .length = bytes, .data = !!(ret & BDRV_BLOCK_DATA), .zero = !!(ret & BDRV_BLOCK_ZERO), - .offset = ret & BDRV_BLOCK_OFFSET_MASK, + .offset = map, .has_offset = has_offset, .depth = depth, .has_filename = file && has_offset, @@ -2839,16 +2822,12 @@ static int img_map(int argc, char **argv) length = blk_getlength(blk); while (curr.start + curr.length < length) { - int64_t nsectors_left; - int64_t sector_num; - int n; - - sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS; + int64_t offset = curr.start + curr.length; + int64_t n; /* Probe up to 1 GiB at a time. */ - nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num; - n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left); - ret = get_block_status(bs, sector_num, n, &next); + n = QEMU_ALIGN_DOWN(MIN(1 << 30, length - offset), BDRV_SECTOR_SIZE); + ret = get_block_status(bs, offset, n, &next); if (ret < 0) { error_report("Could not read file metadata: %s", strerror(-ret)); @@ -3241,70 +3220,58 @@ static int img_rebase(int argc, char **argv) * the image is the same as the original one at any time. */ if (!unsafe) { - int64_t num_sectors; - int64_t old_backing_num_sectors; - int64_t new_backing_num_sectors = 0; - uint64_t sector; - int n; - int64_t count; + int64_t size; + int64_t old_backing_size; + int64_t new_backing_size = 0; + uint64_t offset; + int64_t n; float local_progress = 0; buf_old = blk_blockalign(blk, IO_BUF_SIZE); buf_new = blk_blockalign(blk, IO_BUF_SIZE); - num_sectors = blk_nb_sectors(blk); - if (num_sectors < 0) { + size = blk_getlength(blk); + if (size < 0) { error_report("Could not get size of '%s': %s", - filename, strerror(-num_sectors)); + filename, strerror(-size)); ret = -1; goto out; } - old_backing_num_sectors = blk_nb_sectors(blk_old_backing); - if (old_backing_num_sectors < 0) { + old_backing_size = blk_getlength(blk_old_backing); + if (old_backing_size < 0) { char backing_name[PATH_MAX]; bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)); error_report("Could not get size of '%s': %s", - backing_name, strerror(-old_backing_num_sectors)); + backing_name, strerror(-old_backing_size)); ret = -1; goto out; } if (blk_new_backing) { - new_backing_num_sectors = blk_nb_sectors(blk_new_backing); - if (new_backing_num_sectors < 0) { + new_backing_size = blk_getlength(blk_new_backing); + if (new_backing_size < 0) { error_report("Could not get size of '%s': %s", - out_baseimg, strerror(-new_backing_num_sectors)); + out_baseimg, strerror(-new_backing_size)); ret = -1; goto out; } } - if (num_sectors != 0) { - local_progress = (float)100 / - (num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512)); + if (size != 0) { + local_progress = (float)100 / (size / MIN(size, IO_BUF_SIZE)); } - 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; - } + for (offset = 0; offset < size; offset += n) { + /* How many bytes can we handle with the next read? */ + n = MIN(IO_BUF_SIZE, size - offset); /* If the cluster is allocated, we don't need to take action */ - ret = bdrv_is_allocated(bs, sector << BDRV_SECTOR_BITS, - n << BDRV_SECTOR_BITS, &count); + ret = bdrv_is_allocated(bs, offset, n, &n); if (ret < 0) { error_report("error while reading image metadata: %s", strerror(-ret)); goto out; } - /* TODO relax this once bdrv_is_allocated does not enforce - * sector alignment */ - assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)); - n = count >> BDRV_SECTOR_BITS; if (ret) { continue; } @@ -3313,30 +3280,28 @@ static int img_rebase(int argc, char **argv) * 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); + if (offset >= old_backing_size) { + memset(buf_old, 0, n); } else { - if (sector + n > old_backing_num_sectors) { - n = old_backing_num_sectors - sector; + if (offset + n > old_backing_size) { + n = old_backing_size - offset; } - ret = blk_pread(blk_old_backing, sector << BDRV_SECTOR_BITS, - buf_old, n << BDRV_SECTOR_BITS); + ret = blk_pread(blk_old_backing, offset, buf_old, n); if (ret < 0) { error_report("error while reading from old backing file"); goto out; } } - if (sector >= new_backing_num_sectors || !blk_new_backing) { - memset(buf_new, 0, n * BDRV_SECTOR_SIZE); + if (offset >= new_backing_size || !blk_new_backing) { + memset(buf_new, 0, n); } else { - if (sector + n > new_backing_num_sectors) { - n = new_backing_num_sectors - sector; + if (offset + n > new_backing_size) { + n = new_backing_size - offset; } - ret = blk_pread(blk_new_backing, sector << BDRV_SECTOR_BITS, - buf_new, n << BDRV_SECTOR_BITS); + ret = blk_pread(blk_new_backing, offset, buf_new, n); if (ret < 0) { error_report("error while reading from new backing file"); goto out; @@ -3347,15 +3312,13 @@ static int img_rebase(int argc, char **argv) uint64_t written = 0; while (written < n) { - int pnum; + int64_t pnum; - if (compare_sectors(buf_old + written * 512, - buf_new + written * 512, n - written, &pnum)) + if (compare_buffers(buf_old + written, buf_new + written, + n - written, &pnum)) { - ret = blk_pwrite(blk, - (sector + written) << BDRV_SECTOR_BITS, - buf_old + written * 512, - pnum << BDRV_SECTOR_BITS, 0); + ret = blk_pwrite(blk, offset + written, + buf_old + written, pnum, 0); if (ret < 0) { error_report("Error while writing to COW image: %s", strerror(-ret)); |