diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2023-11-17 17:48:46 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2023-12-24 15:22:49 +0000 |
| commit | bad1a11c0f061aa073bab785389fe04f19ba02e1 (patch) | |
| tree | 1b64827be5dea1969a6605913b127661d4990927 /net/rxrpc | |
| parent | df91b9dfdee23072641570b1efc049f19d839ae8 (diff) | |
rxrpc_find_service_conn_rcu: fix the usage of read_seqbegin_or_lock()
rxrpc_find_service_conn_rcu() should make the "seq" counter odd on the
second pass, otherwise read_seqbegin_or_lock() never takes the lock.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20231117164846.GA10410@redhat.com/
Diffstat (limited to 'net/rxrpc')
| -rw-r--r-- | net/rxrpc/conn_service.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c index 89ac05a711a4..39c908a3ca6e 100644 --- a/net/rxrpc/conn_service.c +++ b/net/rxrpc/conn_service.c @@ -25,7 +25,7 @@ struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *peer, struct rxrpc_conn_proto k; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); struct rb_node *p; - unsigned int seq = 0; + unsigned int seq = 1; k.epoch = sp->hdr.epoch; k.cid = sp->hdr.cid & RXRPC_CIDMASK; @@ -35,6 +35,7 @@ struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *peer, * under just the RCU read lock, so we have to check for * changes. */ + seq++; /* 2 on the 1st/lockless path, otherwise odd */ read_seqbegin_or_lock(&peer->service_conn_lock, &seq); p = rcu_dereference_raw(peer->service_conns.rb_node); |