12.07.2021 14:54, Lukas Straub wrote:
Remove the workaround introduced in commit
6ecbc6c52672db5c13805735ca02784879ce8285
"replication: Avoid blk_make_empty() on read-only child".
It is not needed anymore since s->hidden_disk is guaranteed to be
writable when secondary_do_checkpoint() runs. Because replication_start(),
_do_checkpoint() and _stop() are only called by COLO migration code
and COLO-migration activates all disks via bdrv_invalidate_cache_all()
before it calls these functions.
In replication_child_perm()
we have
if ((bs->open_flags & (BDRV_O_INACTIVE | BDRV_O_RDWR)) == BDRV_O_RDWR) {
*nperm |= BLK_PERM_WRITE;
}
That's probably possible
1. configure a block graph like described in replicatio doc, but all disks
opened read-only. so we don't have WRITE permission
2. start replication
3. crash on trying to make disk empty in do_checkpoint with no WRITE permission
Still, I think if it possible, we'll crash on first bdrv_make_empty of active
disk, and that's preexisting.
So:
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Signed-off-by: Lukas Straub <lukasstra...@web.de>
---
block/replication.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/block/replication.c b/block/replication.c
index 772bb63374..1e9dc4d309 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -356,17 +356,7 @@ static void secondary_do_checkpoint(BlockDriverState *bs,
Error **errp)
return;
}
- BlockBackend *blk = blk_new(qemu_get_current_aio_context(),
- BLK_PERM_WRITE, BLK_PERM_ALL);
- blk_insert_bs(blk, s->hidden_disk->bs, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- blk_unref(blk);
- return;
- }
-
- ret = blk_make_empty(blk, errp);
- blk_unref(blk);
+ ret = bdrv_make_empty(s->hidden_disk, errp);
if (ret < 0) {
return;
}
--
2.20.1
--
Best regards,
Vladimir