[PATCH mptcp-net v2 0/3] mptcp: pm: use _rcu variant under rcu_read_lock

Matthieu Baerts (NGI0) posted 3 patches 3 months, 2 weeks ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/multipath-tcp/mptcp_net-next tags/patchew/20241025-mptcp-pm-lookup._5Faddr._5Frcu-v2-0-1478f6c4b205@kernel.org
There is a newer version of this series
net/mptcp/pm_netlink.c | 69 +++++++++++++++++++++++++++-----------------------
1 file changed, 38 insertions(+), 31 deletions(-)
[PATCH mptcp-net v2 0/3] mptcp: pm: use _rcu variant under rcu_read_lock
Posted by Matthieu Baerts (NGI0) 3 months, 2 weeks ago
When looking at something else, I noticed that the local endpoint
entries list was iterated under rcu_read_lock, but using
list_for_each_entry() instead of the _rcu variant. That's what patch 1
is fixing.

At the previous meeting, Mat and Christoph mentioned we should also use
this _rcu variant in mptcp_pm_nl_set_flags(). But then the modifications
look too important for -net, because __lookup_addr_by_id() also needs to
be modified, and similar parts in the code as well to harmonise how
entries are read from the list. That's what is done in patch 2, for
-next then.

Patch 3 is a simple change to remove duplicated code.

Note: I see that we are using spin_lock_bh(), but the RCU read "locks"
are always used without the _bh() variant. Is that OK here, or did we
miss something?

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Changes in v2:
- Add patch 2 and 3
- Patch 1: avoid > 80 chars per line in __lookup_addr_rcu() + update
  commit message.
- Link to v1: https://lore.kernel.org/r/20241022-mptcp-pm-lookup_addr_rcu-v1-1-19d45f26c872@kernel.org

---
Geliang Tang (1):
      mptcp: pm: avoid code duplication to lookup endp

Matthieu Baerts (NGI0) (2):
      mptcp: pm: use _rcu variant under rcu_read_lock
      mptcp: pm: lockless list traversal

 net/mptcp/pm_netlink.c | 69 +++++++++++++++++++++++++++-----------------------
 1 file changed, 38 insertions(+), 31 deletions(-)
---
base-commit: c2990db510fcdde78645791def80551c0f77ff76
change-id: 20241022-mptcp-pm-lookup_addr_rcu-01833ea95155

Best regards,
-- 
Matthieu Baerts (NGI0) <matttbe@kernel.org>