diff options
| -rw-r--r-- | qemu-img.c | 84 |
1 files changed, 34 insertions, 50 deletions
diff --git a/qemu-img.c b/qemu-img.c index c6b6263853..994365c6a4 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3248,70 +3248,58 @@ 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; } @@ -3320,30 +3308,28 @@ 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; @@ -3353,15 +3339,13 @@ static int img_rebase(int argc, char **argv) /* If they differ, we need to write to the COW file */ uint64_t written = 0; - while (written < n * BDRV_SECTOR_SIZE) { + while (written < n) { int64_t pnum; - if (compare_buffers(buf_old + written, - buf_new + written, - n * BDRV_SECTOR_SIZE - written, &pnum)) + if (compare_buffers(buf_old + written, buf_new + written, + n - written, &pnum)) { - ret = blk_pwrite(blk, - (sector << BDRV_SECTOR_BITS) + written, + ret = blk_pwrite(blk, offset + written, buf_old + written, pnum, 0); if (ret < 0) { error_report("Error while writing to COW image: %s", |