diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 14 |
1 files changed, 11 insertions, 3 deletions
@@ -1517,6 +1517,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, */ void *bounce_buffer; + BlockDriver *drv = bs->drv; struct iovec iov; QEMUIOVector bounce_qiov; int64_t cluster_sector_num; @@ -1537,14 +1538,21 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len); qemu_iovec_init_external(&bounce_qiov, &iov, 1); - ret = bs->drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, - &bounce_qiov); + ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, + &bounce_qiov); if (ret < 0) { goto err; } - ret = bs->drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, + if (drv->bdrv_co_write_zeroes && + buffer_is_zero(bounce_buffer, iov.iov_len)) { + ret = drv->bdrv_co_write_zeroes(bs, cluster_sector_num, + cluster_nb_sectors); + } else { + ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, &bounce_qiov); + } + if (ret < 0) { /* It might be okay to ignore write errors for guest requests. If this * is a deliberate copy-on-read then we don't want to ignore the error. |