diff options
Diffstat (limited to 'blockdev.c')
| -rw-r--r-- | blockdev.c | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/blockdev.c b/blockdev.c index 9126587c45..1eb62b637c 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1197,7 +1197,6 @@ void qmp_drive_mirror(const char *device, const char *target, bool has_on_target_error, BlockdevOnError on_target_error, Error **errp) { - BlockDriverInfo bdi; BlockDriverState *bs; BlockDriverState *source, *target_bs; BlockDriver *proto_drv; @@ -1288,6 +1287,9 @@ void qmp_drive_mirror(const char *device, const char *target, return; } + /* Mirroring takes care of copy-on-write using the source's backing + * file. + */ target_bs = bdrv_new(""); ret = bdrv_open(target_bs, target, flags | BDRV_O_NO_BACKING, drv); @@ -1297,17 +1299,6 @@ void qmp_drive_mirror(const char *device, const char *target, return; } - /* We need a backing file if we will copy parts of a cluster. */ - if (bdrv_get_info(target_bs, &bdi) >= 0 && bdi.cluster_size != 0 && - bdi.cluster_size >= BDRV_SECTORS_PER_DIRTY_CHUNK * 512) { - ret = bdrv_open_backing_file(target_bs); - if (ret < 0) { - bdrv_delete(target_bs); - error_set(errp, QERR_OPEN_FILE_FAILED, target); - return; - } - } - mirror_start(bs, target_bs, speed, sync, on_source_error, on_target_error, block_job_cb, bs, &local_err); if (local_err != NULL) { |