diff options
| -rw-r--r-- | block/backup.c | 12 |
1 files changed, 11 insertions, 1 deletions
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"); |