linux/tools/testing
Willem de Bruijn dbf34acdfb selftests: drv-net: so_txtime: fix qdisc replace with handle
The blamed commit updated a tc replace command by adding a handle.

  -    tc(f"qdisc replace dev {ifname} root {qdisc} {optargs}")
  +    tc(f"qdisc replace dev {ifname} root handle 1: {qdisc} {optargs}")

This breaks the test if the root qdisc already has that handle and is of
different kind, with

  "Invalid qdisc name: must match existing qdisc."

If no handle is asked, or the kind differs, tc replace removes the old
qdisc and grafts a new one.

If a handle is asked and exists, tc replace tries to change the qdisc
in place, for which the kind must be the same.

It does not trigger in all setups, like netdevsim or debian 13, which
do not have root handle 1:. But it is a common root handle.

Solve the bug by first deleting the existing root qdisc if one exists.

Wrap that command in a try block, because it will fail for default
qdiscs with handle 0: with

  "Error: Cannot delete qdisc with handle of zero."

Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20260810183118.32d5c06a@kernel.org/
Fixes: ef3d6cca02 ("selftests: drv-net: so_txtime: only send test traffic to sch_etf")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260811182856.2702163-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-12 17:20:07 -07:00
..
crypto/chacha20-s390 crypto: drbg - Fold include/crypto/drbg.h into crypto/drbg.c 2026-05-07 16:09:59 +08:00
cxl Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (c files) 2026-07-03 07:38:17 +02:00
fault-injection
ktest ktest: Add logfile to failure directory 2026-04-20 15:23:13 -04:00
kunit kunit:tool: Don't write to stdout when it should be disabled 2026-06-07 20:10:30 -06:00
memblock liveupdate: updates for 7.2-rc1 2026-06-21 09:46:14 -07:00
nvdimm
radix-tree MAINTAINERS: update Liam's email address 2026-04-27 05:54:25 -07:00
rbtree
scatterlist
selftests selftests: drv-net: so_txtime: fix qdisc replace with handle 2026-08-12 17:20:07 -07:00
shared mm/slab: improve kmem_cache_alloc_bulk 2026-06-03 18:20:43 +02:00
vma mm/vma: eliminate mmap_action->error_hook, introduce error_override 2026-06-04 14:45:00 -07:00
vsock vsock/test: add test for small packets under pressure 2026-07-21 12:11:06 +02:00