Re: [PATCH mptcp-net v3 0/2] Locking fixes for subflow flag changes

[Paolo Abeni <pabeni@redhat.com>]

On Wed, 2022-06-29 at 15:53 -0700, Mat Martineau wrote:
> When working with Kishen on the userspace PM, the locking code in
> mptcp_pm_nl_mp_prio_send_ack() caught my attention. The
> release-and-reacquire of the PM lock in that function was requiring the
> userspace PM code to grab that lock, even though nothing protected by
> that lock was being accessed. Patch 1 addresses this.
> 
> While investigating that issue, I realized that
> mptcp_pm_nl_mp_prio_send_ack() was not holding the subflow socket lock
> while modifying several parts of the subflow context. Patch 2 addresses
> this, and is not a drastic change since the subflow lock was being
> acquired anyway in mptcp_subflow_send_ack().
> 
> v2->v3: Fix build error
> 
> v1->v2: Based on Paolo's feedback, fix MIB issue with atomic context in
> patch 1 (tested with CONFIG_PREEMPT), and squash patches 2 & 3.
> 
> 
> Mat Martineau (2):
>   mptcp: Avoid acquiring PM lock for subflow priority changes
>   mptcp: Acquire the subflow socket lock before modifying MP_PRIO flags
> 
>  net/mptcp/options.c    |  3 +++
>  net/mptcp/pm_netlink.c | 13 ++++++-------
>  net/mptcp/protocol.c   |  9 +++++++--
>  net/mptcp/protocol.h   |  1 +
>  4 files changed, 17 insertions(+), 9 deletions(-)

LGTM! for the series:

Acked-by: Paolo Abeni <pabeni@redhat.com>