From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Currently backup to nbd target is broken, as nbd doesn't have
.bdrv_get_info realization.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/backup.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/block/backup.c b/block/backup.c
index d1ab617..d3d20db 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -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");
--
1.8.3.1
