diff --git a/block.c b/block.c
index cf08e64add..0fe0152a7c 100644
--- a/block.c
+++ b/block.c
@@ -5398,17 +5398,13 @@ bdrv_replace_node_noperm(BlockDriverState *from,
  *
  * With auto_skip=false the error is returned if from has a parent which should
  * not be updated.
- *
- * With @detach_subchain=true @to must be in a backing chain of @from. In this
- * case backing link of the cow-parent of @to is removed.
  */
 static int GRAPH_WRLOCK
 bdrv_replace_node_common(BlockDriverState *from, BlockDriverState *to,
-                         bool auto_skip, bool detach_subchain, Error **errp)
+                         bool auto_skip, Error **errp)
 {
     Transaction *tran = tran_new();
     g_autoptr(GSList) refresh_list = NULL;
-    BlockDriverState *to_cow_parent = NULL;
     int ret;
 
     GLOBAL_STATE_CODE();
@@ -5417,17 +5413,6 @@ bdrv_replace_node_common(BlockDriverState *from, BlockDriverState *to,
     assert(to->quiesce_counter);
     assert(bdrv_get_aio_context(from) == bdrv_get_aio_context(to));
 
-    if (detach_subchain) {
-        assert(bdrv_chain_contains(from, to));
-        assert(from != to);
-        for (to_cow_parent = from;
-             bdrv_filter_or_cow_bs(to_cow_parent) != to;
-             to_cow_parent = bdrv_filter_or_cow_bs(to_cow_parent))
-        {
-            ;
-        }
-    }
-
     /*
      * Do the replacement without permission update.
      * Replacement may influence the permissions, we should calculate new
@@ -5439,11 +5424,6 @@ bdrv_replace_node_common(BlockDriverState *from, BlockDriverState *to,
         goto out;
     }
 
-    if (detach_subchain) {
-        /* to_cow_parent is already drained because from is drained */
-        bdrv_remove_child(bdrv_filter_or_cow_child(to_cow_parent), tran);
-    }
-
     refresh_list = g_slist_prepend(refresh_list, to);
     refresh_list = g_slist_prepend(refresh_list, from);
 
@@ -5462,7 +5442,7 @@ out:
 int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
                       Error **errp)
 {
-    return bdrv_replace_node_common(from, to, true, false, errp);
+    return bdrv_replace_node_common(from, to, true, errp);
 }
 
 int bdrv_drop_filter(BlockDriverState *bs, Error **errp)
@@ -5478,7 +5458,7 @@ int bdrv_drop_filter(BlockDriverState *bs, Error **errp)
 
     bdrv_drained_begin(child_bs);
     bdrv_graph_wrlock();
-    ret = bdrv_replace_node_common(bs, child_bs, true, true, errp);
+    ret = bdrv_replace_node_common(bs, child_bs, true, errp);
     bdrv_graph_wrunlock();
     bdrv_drained_end(child_bs);
 
@@ -5929,17 +5909,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
         updated_children = g_slist_prepend(updated_children, c);
     }
 
-    /*
-     * It seems correct to pass detach_subchain=true here, but it triggers
-     * one more yet not fixed bug, when due to nested aio_poll loop we switch to
-     * another drained section, which modify the graph (for example, removing
-     * the child, which we keep in updated_children list). So, it's a TODO.
-     *
-     * Note, bug triggered if pass detach_subchain=true here and run
-     * test-bdrv-drain. test_drop_intermediate_poll() test-case will crash.
-     * That's a FIXME.
-     */
-    bdrv_replace_node_common(top, base, false, false, &local_err);
+    bdrv_replace_node_common(top, base, false, &local_err);
     bdrv_graph_wrunlock();
 
     if (local_err) {
diff --git a/tests/qemu-iotests/257 b/tests/qemu-iotests/257
index 7d3720b8e5..cd0468aaa1 100755
--- a/tests/qemu-iotests/257
+++ b/tests/qemu-iotests/257
@@ -310,14 +310,18 @@ def test_bitmap_sync(bsync_mode, msync_mode='bitmap', failure=None):
                     'state': 1,
                     'new_state': 2
                 }, {
-                    'event': 'read_aio',
+                    'event': 'flush_to_disk',
                     'state': 2,
                     'new_state': 3
+                }, {
+                    'event': "read_aio",
+                    'state': 3,
+                    'new_state': 4
                 }],
                 'inject-error': [{
                     'event': 'read_aio',
                     'errno': 5,
-                    'state': 3,
+                    'state': 4,
                     'immediately': False,
                     'once': True
                 }]
diff --git a/tests/qemu-iotests/257.out b/tests/qemu-iotests/257.out
index c33dd7f3a9..fb28333cb2 100644
--- a/tests/qemu-iotests/257.out
+++ b/tests/qemu-iotests/257.out
@@ -272,7 +272,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---
@@ -1017,7 +1017,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---
@@ -1762,7 +1762,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---
@@ -2507,7 +2507,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---
@@ -3252,7 +3252,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---
@@ -3997,7 +3997,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---
@@ -4742,7 +4742,7 @@ qemu_img compare "TEST_DIR/PID-img" "TEST_DIR/PID-fbackup2" ==> Identical, OK!
 
 --- Preparing image & VM ---
 
-{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 3}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "read_aio", "new-state": 3, "state": 2}]}, "node-name": "drive0"}}
+{"execute": "blockdev-add", "arguments": {"driver": "qcow2", "file": {"driver": "blkdebug", "image": {"driver": "file", "filename": "TEST_DIR/PID-img"}, "inject-error": [{"errno": 5, "event": "read_aio", "immediately": false, "once": true, "state": 4}], "set-state": [{"event": "flush_to_disk", "new-state": 2, "state": 1}, {"event": "flush_to_disk", "new-state": 3, "state": 2}, {"event": "read_aio", "new-state": 4, "state": 3}]}, "node-name": "drive0"}}
 {"return": {}}
 
 --- Write #0 ---