diff options
| -rw-r--r-- | qemu-img.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/qemu-img.c b/qemu-img.c index 0725f22cc2..76f05f2e94 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1129,8 +1129,7 @@ out3: static int img_convert(int argc, char **argv) { - int c, n, n1, bs_n, bs_i, compress, cluster_size, - cluster_sectors, skip_create; + int c, n, n1, bs_n, bs_i, compress, cluster_sectors, skip_create; int64_t ret = 0; int progress = 0, flags; const char *fmt, *out_fmt, *cache, *out_baseimg, *out_filename; @@ -1424,19 +1423,23 @@ static int img_convert(int argc, char **argv) } } - if (compress) { - ret = bdrv_get_info(out_bs, &bdi); - if (ret < 0) { + cluster_sectors = 0; + ret = bdrv_get_info(out_bs, &bdi); + if (ret < 0) { + if (compress) { error_report("could not get block driver info"); goto out; } - cluster_size = bdi.cluster_size; - if (cluster_size <= 0 || cluster_size > bufsectors * BDRV_SECTOR_SIZE) { + } else { + cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE; + } + + if (compress) { + if (cluster_sectors <= 0 || cluster_sectors > bufsectors) { error_report("invalid cluster size"); ret = -1; goto out; } - cluster_sectors = cluster_size >> 9; sector_num = 0; nb_sectors = total_sectors; @@ -1569,6 +1572,19 @@ static int img_convert(int argc, char **argv) } n = MIN(nb_sectors, bufsectors); + + /* round down request length to an aligned sector, but + * do not bother doing this on short requests. They happen + * when we found an all-zero area, and the next sector to + * write will not be sector_num + n. */ + if (cluster_sectors > 0 && n >= cluster_sectors) { + int64_t next_aligned_sector = (sector_num + n); + next_aligned_sector -= next_aligned_sector % cluster_sectors; + if (sector_num + n > next_aligned_sector) { + n = next_aligned_sector - sector_num; + } + } + n = MIN(n, bs_sectors - (sector_num - bs_offset)); n1 = n; |