diff options
| -rw-r--r-- | qemu-img.c | 61 |
1 files changed, 34 insertions, 27 deletions
diff --git a/qemu-img.c b/qemu-img.c index 71c92f142a..cfa44b4153 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3312,26 +3312,30 @@ static int img_rebase(int argc, char **argv) char backing_name[PATH_MAX]; QDict *options = NULL; - if (bs->backing_format[0] != '\0') { - options = qdict_new(); - qdict_put_str(options, "driver", bs->backing_format); - } - - if (force_share) { - if (!options) { + if (bs->backing) { + if (bs->backing_format[0] != '\0') { options = qdict_new(); + qdict_put_str(options, "driver", bs->backing_format); } - qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); - } - bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)); - blk_old_backing = blk_new_open(backing_name, NULL, - options, src_flags, &local_err); - if (!blk_old_backing) { - error_reportf_err(local_err, - "Could not open old backing file '%s': ", - backing_name); - ret = -1; - goto out; + + if (force_share) { + if (!options) { + options = qdict_new(); + } + qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); + } + bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)); + blk_old_backing = blk_new_open(backing_name, NULL, + options, src_flags, &local_err); + if (!blk_old_backing) { + error_reportf_err(local_err, + "Could not open old backing file '%s': ", + backing_name); + ret = -1; + goto out; + } + } else { + blk_old_backing = NULL; } if (out_baseimg[0]) { @@ -3384,7 +3388,7 @@ static int img_rebase(int argc, char **argv) */ if (!unsafe) { int64_t size; - int64_t old_backing_size; + int64_t old_backing_size = 0; int64_t new_backing_size = 0; uint64_t offset; int64_t n; @@ -3400,15 +3404,18 @@ static int img_rebase(int argc, char **argv) ret = -1; goto out; } - old_backing_size = blk_getlength(blk_old_backing); - if (old_backing_size < 0) { - char backing_name[PATH_MAX]; + if (blk_old_backing) { + old_backing_size = blk_getlength(blk_old_backing); + if (old_backing_size < 0) { + char backing_name[PATH_MAX]; - bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)); - error_report("Could not get size of '%s': %s", - backing_name, strerror(-old_backing_size)); - ret = -1; - goto out; + bdrv_get_backing_filename(bs, backing_name, + sizeof(backing_name)); + error_report("Could not get size of '%s': %s", + backing_name, strerror(-old_backing_size)); + ret = -1; + goto out; + } } if (blk_new_backing) { new_backing_size = blk_getlength(blk_new_backing); |