On Sun, 04/09 20:37, jemmy858...@gmail.com wrote:
> From: Lidong Chen <lidongc...@tencent.com>
>
> BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default,
> this maybe cause the qcow2 file size is bigger after migration.
> This patch check each cluster, use blk_pwrite_zeroes for each
> zero cluster.
>
> Signed-off-by: Lidong Chen <lidongc...@tencent.com>
> ---
> migration/block.c | 38 ++++++++++++++++++++++++++++++++++++--
> 1 file changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/migration/block.c b/migration/block.c
> index 7734ff7..fe613db 100644
> --- a/migration/block.c
> +++ b/migration/block.c
> @@ -885,6 +885,8 @@ static int block_load(QEMUFile *f, void *opaque, int
> version_id)
> int64_t total_sectors = 0;
> int nr_sectors;
> int ret;
> + BlockDriverInfo bdi;
> + int cluster_size;
>
> do {
> addr = qemu_get_be64(f);
> @@ -934,8 +936,40 @@ static int block_load(QEMUFile *f, void *opaque, int
> version_id)
> } else {
> buf = g_malloc(BLOCK_SIZE);
> qemu_get_buffer(f, buf, BLOCK_SIZE);
> - ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
> - nr_sectors * BDRV_SECTOR_SIZE, 0);
> +
> + ret = bdrv_get_info(blk_bs(blk), &bdi);
> + cluster_size = bdi.cluster_size;
> +
> + if (ret == 0 && cluster_size > 0 &&
> + cluster_size <= BLOCK_SIZE &&
> + BLOCK_SIZE % cluster_size == 0) {
> + int i;
> + int64_t cur_addr;
> + uint8_t *cur_buf;
> +
> + for (i = 0; i < BLOCK_SIZE / cluster_size; i++) {
> + cur_addr = addr * BDRV_SECTOR_SIZE
> + + i * cluster_size;
> + cur_buf = buf + i * cluster_size;
> +
> + if (buffer_is_zero(cur_buf, cluster_size)) {
> + ret = blk_pwrite_zeroes(blk, cur_addr,
> + cluster_size,
> + BDRV_REQ_MAY_UNMAP);
> + } else {
> + ret = blk_pwrite(blk, cur_addr, cur_buf,
> + cluster_size, 0);
> + }
> +
> + if (ret < 0) {
> + g_free(buf);
> + return ret;
> + }
This if block is not necessary because...
> + }
> + } else {
> + ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
> + nr_sectors * BDRV_SECTOR_SIZE, 0);
> + }
> g_free(buf);
...
if (ret < 0) {
return ret;
}
> }
>
> --
> 1.8.3.1
>
>
If you remove that:
Reviewed-by: Fam Zheng <f...@redhat.com>
