selftests: rds: Fix more pylint errors

This patch fixes a few pylint errors in test.py. Remove unused exception
variables from except blocks, and disable warnings for imports that cannot
appear at the start of the module.  Also disable warnings for the
tcpdump processes.  The suggestion to use a with block does not apply
here since the process needs to outlive the parent to collect the dumps.
Lastly add the module docstring at the top of the module.

Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260504054143.4027538-4-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/rds/test.py b/tools/testing/selftests/net/rds/test.py
index 93e23e8b256ce871d93e496f4ad88ebc84337cac..4b6ffbb3a81cb2f4e8c70c9243aa27b69e2501ba 100755 (executable)
--- a/tools/testing/selftests/net/rds/test.py
+++ b/tools/testing/selftests/net/rds/test.py
@@ -1,5 +1,8 @@
 #! /usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0
+"""
+This module provides functional testing for the net/rds component.
+"""
 
 import argparse
 import ctypes
@@ -17,7 +20,8 @@ import shutil
 # Allow utils module to be imported from different directory
 this_dir = os.path.dirname(os.path.realpath(__file__))
 sys.path.append(os.path.join(this_dir, "../"))
-from lib.py.utils import ip
+# pylint: disable-next=wrong-import-position,import-error,no-name-in-module
+from lib.py.utils import ip # noqa: E402
 
 libc = ctypes.cdll.LoadLibrary('libc.so.6')
 setns = libc.setns
@@ -129,6 +133,7 @@ tcpdump_procs = []
 for net in [NET0, NET1]:
     pcap = logdir+'/'+net+'.pcap'
     fd, pcap_tmp = tempfile.mkstemp(suffix=".pcap", prefix=f"{net}-", dir="/tmp")
+    # pylint: disable-next=consider-using-with
     p = subprocess.Popen(
         ['ip', 'netns', 'exec', net,
          '/usr/sbin/tcpdump', '-i', 'any', '-w', pcap_tmp])
@@ -192,7 +197,7 @@ while nr_send < NUM_PACKETS:
             send_hashes.setdefault((sender.fileno(), receiver.fileno()),
                     hashlib.sha256()).update(f'<{send_data}>'.encode('utf-8'))
             nr_send = nr_send + 1
-        except BlockingIOError as e:
+        except BlockingIOError:
             break
         except OSError as e:
             if e.errno in [errno.ENOBUFS, errno.ECONNRESET, errno.EPIPE]:
@@ -214,7 +219,7 @@ while nr_send < NUM_PACKETS:
                             receiver.fileno()), hashlib.sha256()).update(
                                     f'<{recv_data}>'.encode('utf-8'))
                         nr_recv = nr_recv + 1
-                    except BlockingIOError as e:
+                    except BlockingIOError:
                         break
 
     # exercise net/rds/tcp.c:rds_tcp_sysctl_reset()