diff options
| author | David Howells <dhowells@redhat.com> | 2025-02-18 19:22:45 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-02-21 15:06:29 -0800 |
| commit | 833fefa074444b1e7f7e834cbdce59ce02562ed0 (patch) | |
| tree | 1d9267e1e6447b2228990d7cb622210b316a044c /net/rxrpc/input.c | |
| parent | c34d999ca3145d9fe858258cc3342ec493f47d2e (diff) | |
rxrpc: peer->mtu_lock is redundant
The peer->mtu_lock is only used to lock around writes to peer->max_data -
and nothing else; further, all such writes take place in the I/O thread and
the lock is only ever write-locked and never read-locked.
In a couple of places, the write_seqcount_begin() is wrapped in
preempt_disable/enable(), but not in all places. This can cause lockdep to
complain:
WARNING: CPU: 0 PID: 1549 at include/linux/seqlock.h:221 rxrpc_input_ack_trailer+0x305/0x430
...
RIP: 0010:rxrpc_input_ack_trailer+0x305/0x430
Fix this by just getting rid of the lock.
Fixes: eeaedc5449d9 ("rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250218192250.296870-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/rxrpc/input.c')
| -rw-r--r-- | net/rxrpc/input.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index 9047ba13bd31..24aceb183c2c 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -810,9 +810,7 @@ static void rxrpc_input_ack_trailer(struct rxrpc_call *call, struct sk_buff *skb if (max_mtu < peer->max_data) { trace_rxrpc_pmtud_reduce(peer, sp->hdr.serial, max_mtu, rxrpc_pmtud_reduce_ack); - write_seqcount_begin(&peer->mtu_lock); peer->max_data = max_mtu; - write_seqcount_end(&peer->mtu_lock); } max_data = umin(max_mtu, peer->max_data); |