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| author | David Howells <dhowells@redhat.com> | 2017-09-04 15:28:28 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-09-05 14:39:17 -0700 |
| commit | fdade4f69e4ca29753963f858dc42c5f8faf1d0b (patch) | |
| tree | 2747b8d05e5dfb48bb9ed17eeab124b835797388 /net | |
| parent | 5e369aefdce4818c8264b81d3436eccf35af561e (diff) | |
| download | linux-fdade4f69e4ca29753963f858dc42c5f8faf1d0b.tar.gz | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/rxrpc/conn_service.c | 3 |
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; |