BlockJob *backup_job_create(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 NULL; } if (!bdrv_is_inserted(bs)) { error_setg(errp, "Device is not inserted: %s", bdrv_get_device_name(bs)); return NULL; } if (!bdrv_is_inserted(target)) { error_setg(errp, "Device is not inserted: %s", bdrv_get_device_name(target)); return NULL; } 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 NULL; } if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) { return NULL; } if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) { return NULL; } if (sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) { if (!sync_bitmap) { error_setg(errp, "must provide a valid bitmap name for " "\"incremental\" sync mode"); return NULL; } /* Create a new bitmap, and freeze/disable this one. */ if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0) { return NULL; } } 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 NULL; } 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->common.len is fixed, so we can't allow resize */ job = block_job_create(job_id, &backup_job_driver, bs, BLK_PERM_CONSISTENT_READ, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD, speed, creation_flags, cb, opaque, errp); if (!job) { goto error; } /* The target must match the source in size, so no resize here either */ job->target = blk_new(BLK_PERM_WRITE, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD); ret = blk_insert_bs(job->target, target, errp); if (ret < 0) { goto error; } 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 == -ENOTSUP && !target->backing) { /* Cluster size is not defined */ error_report("WARNING: The target block device doesn't provide " "information about the block size and it doesn't have a " "backing file. The default block size of %u bytes is " "used. If the actual block size of the target exceeds " "this default, the backup may be unusable", BACKUP_CLUSTER_SIZE_DEFAULT); job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT; } else 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); } /* Required permissions are already taken with target's blk_new() */ block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL, &error_abort); job->common.len = len; block_job_txn_add_job(txn, &job->common); return &job->common; error: if (sync_bitmap) { bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL); } if (job) { backup_clean(&job->common); block_job_early_fail(&job->common); } return NULL; }