In safe mode we open the entire chain, including the parent backing
file of the rebased file.
Do not open a new BlockBackend for the parent backing file, which
saves opening the rest of the chain twice, which for long chains
saves many "pricy" bdrv_open() calls.
Permissions for blk_new() were copied from blk_new_open() when
flags = 0.
Reviewed-by: Karl Heubaum <karl.heub...@oracle.com>
Reviewed-by: Eyal Moscovici <eyal.moscov...@oracle.com>
Signed-off-by: Sagi Amit <sagi.a...@oracle.com>
Co-developed-by: Sagi Amit <sagi.a...@oracle.com>
Signed-off-by: Sam Eiderman <shmuel.eider...@oracle.com>
---
qemu-img.c | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index 28fba1e7a7..9bd0bb1e47 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3309,29 +3309,18 @@ static int img_rebase(int argc, char **argv)
/* For safe rebasing we need to compare old and new backing file */
if (!unsafe) {
- char backing_name[PATH_MAX];
QDict *options = NULL;
+ BlockDriverState *base_bs = backing_bs(bs);
- if (bs->backing) {
- if (bs->backing_format[0] != '\0') {
- options = qdict_new();
- qdict_put_str(options, "driver", bs->backing_format);
- }
-
- 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) {
+ if (base_bs) {
+ blk_old_backing = blk_new(BLK_PERM_CONSISTENT_READ,
+ BLK_PERM_ALL);
+ ret = blk_insert_bs(blk_old_backing, base_bs,
+ &local_err);
+ if (ret < 0) {
error_reportf_err(local_err,
- "Could not open old backing file '%s': ",
- backing_name);
- ret = -1;
+ "Could not reuse old backing file '%s': ",
+ base_bs->filename);
goto out;
}
} else {
--
2.13.3
