selftests: net: shaper: Add child node deletion reparent test

Add delete_child_reparent to verify that deleting a child node
reparents its queue leaves to the parent node. Creates a two-level
hierarchy (N1 with Q1,Q2 and child N2 with Q3), deletes N2, and
verifies Q3's parent becomes N1.

Signed-off-by: Mohsin Bashir <hmohsin@meta.com>
Link: https://patch.msgid.link/20260805030936.1092907-9-mohsin.bashr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/tools/testing/selftests/drivers/net/shaper.py b/tools/testing/selftests/drivers/net/shaper.py
index 3b72661202f9..1b88e183f1b9 100755
--- a/tools/testing/selftests/drivers/net/shaper.py
+++ b/tools/testing/selftests/drivers/net/shaper.py
@@ -648,6 +648,82 @@ def nested_depth_limit(cfg, nl_shaper) -> None:
         cleanup.exec()
     ksft_eq(len(nl_shaper.get({'ifindex': cfg.ifindex}, dump=True)), 0)
 
+def delete_child_reparent(cfg, nl_shaper) -> None:
+    r"""Deleting a child node reparents its queue leaf to the parent.
+
+        netdev              netdev
+          |                   |
+          N1      del N2      N1
+        / | \     ----->    / | \
+      Q1 Q2 N2            Q1 Q2 Q3
+             |
+            Q3
+    """
+    n1_bw_max = 10000
+    n2_bw_max = 5000
+
+    _require_caps(cfg, nl_shaper, 'node',
+                  ['support-bw-max', 'support-metric-bps', 'support-nesting'],
+                  "device does not support node scope shapers with bw_max, metric bps and nesting")
+    _require_caps(cfg, nl_shaper, 'queue', ['support-nesting', 'support-weight'],
+                  "device does not support nested queue scope shapers with weight")
+
+    _require_queues(cfg, 4)
+
+    # Create parent node N1 with Q1, Q2
+    n1_handle = nl_shaper.group({
+                   'ifindex': cfg.ifindex,
+                   'leaves':[{'handle': {'scope': 'queue', 'id': 1},
+                              'weight': 1},
+                             {'handle': {'scope': 'queue', 'id': 2},
+                              'weight': 1}],
+                   'handle': {'scope':'node'},
+                   'metric': 'bps',
+                   'bw-max': n1_bw_max})
+    n1_id = n1_handle['handle']['id']
+    for i in range(1, 3):
+        defer(_delete_shaper, cfg, nl_shaper, {'scope': 'queue', 'id': i})
+
+    # Create child node N2 under N1 with Q3
+    n2_handle = nl_shaper.group({
+                   'ifindex': cfg.ifindex,
+                   'leaves':[{'handle': {'scope': 'queue', 'id': 3},
+                              'weight': 1}],
+                   'handle': {'scope':'node'},
+                   'parent': {'scope': 'node', 'id': n1_id},
+                   'metric': 'bps',
+                   'bw-max': n2_bw_max})
+    n2_id = n2_handle['handle']['id']
+    defer(_delete_shaper, cfg, nl_shaper, {'scope': 'queue', 'id': 3})
+
+    # Delete child N2 - Q3 should reparent to N1
+    nl_shaper.delete({'ifindex': cfg.ifindex,
+                      'handle': {'scope': 'node', 'id': n2_id}})
+
+    with ksft_raises(NlError):
+        nl_shaper.get({'ifindex': cfg.ifindex,
+                       'handle': {'scope': 'node', 'id': n2_id}})
+
+    shaper_n1 = nl_shaper.get({'ifindex': cfg.ifindex,
+                               'handle': {'scope': 'node', 'id': n1_id}})
+    ksft_eq(shaper_n1, {'ifindex': cfg.ifindex,
+                        'handle': {'scope': 'node', 'id': n1_id},
+                        'parent': {'scope': 'netdev'},
+                        'metric': 'bps',
+                        'bw-max': n1_bw_max})
+    shaper_q3 = nl_shaper.get({'ifindex': cfg.ifindex,
+                               'handle': {'scope': 'queue', 'id': 3}})
+    ksft_eq(shaper_q3, {'ifindex': cfg.ifindex,
+                        'parent': {'scope': 'node', 'id': n1_id},
+                        'handle': {'scope': 'queue', 'id': 3},
+                        'weight': 1})
+
+    # Cleanup
+    for i in range(1, 4):
+        _delete_shaper(cfg, nl_shaper, {'scope': 'queue', 'id': i})
+    shapers = nl_shaper.get({'ifindex': cfg.ifindex}, dump=True)
+    ksft_eq(len(shapers), 0)
+
 def queue_update(cfg, nl_shaper) -> None:
     nq = _require_queues(cfg, 4)
     if not cfg.queues:
@@ -765,6 +841,7 @@ def main() -> None:
                   group_update_rate,
                   delegation,
                   nested_depth_limit,
+                  delete_child_reparent,
                   dup_leaves,
                   queue_update],
                  args=(cfg, NetshaperFamily()))