backup: allow target without .bdrv_get_info

Currently backup to nbd target is broken, as nbd doesn't have
.bdrv_get_info realization.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2017-02-28 22:33:40 +03:00 committed by Kevin Wolf
parent dd4d257821
commit a410a7f1af
1 changed files with 11 additions and 1 deletions

View File

@ -24,6 +24,7 @@
#include "qemu/cutils.h"
#include "sysemu/block-backend.h"
#include "qemu/bitmap.h"
#include "qemu/error-report.h"
#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
#define SLICE_TIME 100000000ULL /* ns */
@ -648,7 +649,16 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
* 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) {
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");