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authorDavid Howells2017-09-04 15:28:28 +0100
committerDavid S. Miller2017-09-05 14:39:17 -0700
commitfdade4f69e4ca29753963f858dc42c5f8faf1d0b (patch)
tree2747b8d05e5dfb48bb9ed17eeab124b835797388
parent5e369aefdce4818c8264b81d3436eccf35af561e (diff)
rxrpc: Make service connection lookup always check for retry
When an RxRPC service packet comes in, the target connection is looked up by an rb-tree search under RCU and a read-locked seqlock; the seqlock retry check is, however, currently skipped if we got a match, but probably shouldn't be in case the connection we found gets replaced whilst we're doing a search. Make the lookup procedure always go through need_seqretry(), even if the lookup was successful. This makes sure we always pick up on a write-lock event. On the other hand, since we don't take a ref on the object, but rely on RCU to prevent its destruction after dropping the seqlock, I'm not sure this is necessary. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/rxrpc/conn_service.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c
index e60fcd2a4a02..f6fcdb3130a1 100644
--- a/net/rxrpc/conn_service.c
+++ b/net/rxrpc/conn_service.c
@@ -50,12 +50,11 @@ struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *peer,
else if (conn->proto.index_key > k.index_key)
p = rcu_dereference_raw(p->rb_right);
else
- goto done;
+ break;
conn = NULL;
}
} while (need_seqretry(&peer->service_conn_lock, seq));
-done:
done_seqretry(&peer->service_conn_lock, seq);
_leave(" = %d", conn ? conn->debug_id : -1);
return conn;