void backup_start(const char *job_id, BlockDriverState *bs, BlockDriverState *target, int64_t speed, MirrorSyncMode sync_mode, BdrvDirtyBitmap *sync_bitmap, bool compress, BlockdevOnError on_source_error, BlockdevOnError on_target_error, int creation_flags, BlockCompletionFunc *cb, void *opaque, BlockJobTxn *txn, Error **errp) { int64_t len; BlockDriverInfo bdi; BackupBlockJob *job = NULL; int ret; assert(bs); assert(target); if (bs == target) { error_setg(errp, "Source and target cannot be the same"); return; } if (!bdrv_is_inserted(bs)) { error_setg(errp, "Device is not inserted: %s", bdrv_get_device_name(bs)); return; } if (!bdrv_is_inserted(target)) { error_setg(errp, "Device is not inserted: %s", bdrv_get_device_name(target)); return; } if (compress && target->drv->bdrv_co_pwritev_compressed == NULL) { error_setg(errp, "Compression is not supported for this drive %s", bdrv_get_device_name(target)); return; } if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) { return; } if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) { return; } if (sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) { if (!sync_bitmap) { error_setg(errp, "must provide a valid bitmap name for " "\"incremental\" sync mode"); return; } /* Create a new bitmap, and freeze/disable this one. */ if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0) { return; } } else if (sync_bitmap) { error_setg(errp, "a sync_bitmap was provided to backup_run, " "but received an incompatible sync_mode (%s)", MirrorSyncMode_lookup[sync_mode]); return; } len = bdrv_getlength(bs); if (len < 0) { error_setg_errno(errp, -len, "unable to get length for '%s'", bdrv_get_device_name(bs)); goto error; } job = block_job_create(job_id, &backup_job_driver, bs, speed, creation_flags, cb, opaque, errp); if (!job) { goto error; } job->target = blk_new(); blk_insert_bs(job->target, target); job->on_source_error = on_source_error; job->on_target_error = on_target_error; job->sync_mode = sync_mode; job->sync_bitmap = sync_mode == MIRROR_SYNC_MODE_INCREMENTAL ? sync_bitmap : NULL; job->compress = compress; /* If there is no backing file on the target, we cannot rely on COW if our * backup cluster size is smaller than the target cluster size. Even for * targets with a backing file, try to avoid COW if possible. */ ret = bdrv_get_info(target, &bdi); if (ret < 0 && !target->backing) { error_setg_errno(errp, -ret, "Couldn't determine the cluster size of the target image, " "which has no backing file"); error_append_hint(errp, "Aborting, since this may create an unusable destination image\n"); goto error; } else if (ret < 0 && target->backing) { /* Not fatal; just trudge on ahead. */ job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT; } else { job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size); } block_job_add_bdrv(&job->common, target); job->common.len = len; job->common.co = qemu_coroutine_create(backup_run, job); block_job_txn_add_job(txn, &job->common); qemu_coroutine_enter(job->common.co); return; error: if (sync_bitmap) { bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL); } if (job) { blk_unref(job->target); block_job_unref(&job->common); } }