diff --git a/block/copy-before-write.c b/block/copy-before-write.c index a7996d54db..2a51cc64e4 100644 --- a/block/copy-before-write.c +++ b/block/copy-before-write.c @@ -142,10 +142,12 @@ static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c, bdrv_default_perms(bs, c, role, reopen_queue, perm, shared, nperm, nshared); - if (perm & BLK_PERM_WRITE) { - *nperm = *nperm | BLK_PERM_CONSISTENT_READ; + if (!QLIST_EMPTY(&bs->parents)) { + if (perm & BLK_PERM_WRITE) { + *nperm = *nperm | BLK_PERM_CONSISTENT_READ; + } + *nshared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); } - *nshared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); } } diff --git a/tests/qemu-iotests/283.out b/tests/qemu-iotests/283.out index f2b7219632..5bb75952ef 100644 --- a/tests/qemu-iotests/283.out +++ b/tests/qemu-iotests/283.out @@ -5,7 +5,7 @@ {"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}} {"return": {}} {"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}} -{"error": {"class": "GenericError", "desc": "Cannot append copy-before-write filter: Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}} +{"error": {"class": "GenericError", "desc": "Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}} === copy-before-write filter should be gone after job-finalize ===