The new blk_co_copy_range interface offers a more efficient way in the case of network based storage. Make use of it to allow faster convert operation.
Since copy offloading cannot do zero detection ('-S') and compression (-c), only try it when these options are not used. Signed-off-by: Fam Zheng <f...@redhat.com> --- qemu-img.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 855fa52514..268b749592 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1544,6 +1544,7 @@ typedef struct ImgConvertState { bool compressed; bool target_has_backing; bool wr_in_order; + bool copy_range; int min_sparse; size_t cluster_sectors; size_t buf_sectors; @@ -1737,6 +1738,37 @@ static int coroutine_fn convert_co_write(ImgConvertState *s, int64_t sector_num, return 0; } +static int coroutine_fn convert_co_copy_range(ImgConvertState *s, int64_t sector_num, + int nb_sectors) +{ + int n, ret; + + while (nb_sectors > 0) { + BlockBackend *blk; + int src_cur; + int64_t bs_sectors, src_cur_offset; + int64_t offset; + + convert_select_part(s, sector_num, &src_cur, &src_cur_offset); + offset = (sector_num - src_cur_offset) << BDRV_SECTOR_BITS; + blk = s->src[src_cur]; + bs_sectors = s->src_sectors[src_cur]; + + n = MIN(nb_sectors, bs_sectors - (sector_num - src_cur_offset)); + + ret = blk_co_copy_range(blk, offset, s->target, + sector_num << BDRV_SECTOR_BITS, + n << BDRV_SECTOR_BITS, 0); + if (ret < 0) { + return ret; + } + + sector_num += n; + nb_sectors -= n; + } + return 0; +} + static void coroutine_fn convert_co_do_copy(void *opaque) { ImgConvertState *s = opaque; @@ -1759,6 +1791,7 @@ static void coroutine_fn convert_co_do_copy(void *opaque) int n; int64_t sector_num; enum ImgConvertBlockStatus status; + bool copy_range; qemu_co_mutex_lock(&s->lock); if (s->ret != -EINPROGRESS || s->sector_num >= s->total_sectors) { @@ -1788,7 +1821,9 @@ static void coroutine_fn convert_co_do_copy(void *opaque) s->allocated_sectors, 0); } - if (status == BLK_DATA) { +retry: + copy_range = s->copy_range && s->status == BLK_DATA; + if (status == BLK_DATA && !copy_range) { ret = convert_co_read(s, sector_num, n, buf); if (ret < 0) { error_report("error while reading sector %" PRId64 @@ -1810,7 +1845,15 @@ static void coroutine_fn convert_co_do_copy(void *opaque) } if (s->ret == -EINPROGRESS) { - ret = convert_co_write(s, sector_num, n, buf, status); + if (copy_range) { + ret = convert_co_copy_range(s, sector_num, n); + if (ret) { + s->copy_range = false; + goto retry; + } + } else { + ret = convert_co_write(s, sector_num, n, buf, status); + } if (ret < 0) { error_report("error while writing sector %" PRId64 ": %s", sector_num, strerror(-ret)); @@ -1933,6 +1976,7 @@ static int img_convert(int argc, char **argv) ImgConvertState s = (ImgConvertState) { /* Need at least 4k of zeros for sparse detection */ .min_sparse = 8, + .copy_range = true, .buf_sectors = IO_BUF_SIZE / BDRV_SECTOR_SIZE, .wr_in_order = true, .num_coroutines = 8, @@ -1973,6 +2017,7 @@ static int img_convert(int argc, char **argv) break; case 'c': s.compressed = true; + s.copy_range = false; break; case 'o': if (!is_valid_option_list(optarg)) { @@ -2014,6 +2059,7 @@ static int img_convert(int argc, char **argv) } s.min_sparse = sval / BDRV_SECTOR_SIZE; + s.copy_range = false; break; } case 'p': -- 2.14.3