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author | Ka-Cheong Poon <ka-cheong.poon@oracle.com> | 2018-04-11 09:57:25 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-04-11 16:24:01 +0200 |
commit | a43cced9a348901f9015f4730b70b69e7c41a9c9 (patch) | |
tree | ec0daa4fc626f408f90f69d17705e24abb39c016 /net/rds | |
parent | ip_gre: clear feature flags when incompatible o_flags are set (diff) | |
download | linux-a43cced9a348901f9015f4730b70b69e7c41a9c9.tar.xz linux-a43cced9a348901f9015f4730b70b69e7c41a9c9.zip |
rds: MP-RDS may use an invalid c_path
rds_sendmsg() calls rds_send_mprds_hash() to find a c_path to use to
send a message. Suppose the RDS connection is not yet up. In
rds_send_mprds_hash(), it does
if (conn->c_npaths == 0)
wait_event_interruptible(conn->c_hs_waitq,
(conn->c_npaths != 0));
If it is interrupted before the connection is set up,
rds_send_mprds_hash() will return a non-zero hash value. Hence
rds_sendmsg() will use a non-zero c_path to send the message. But if
the RDS connection ends up to be non-MP capable, the message will be
lost as only the zero c_path can be used.
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds')
-rw-r--r-- | net/rds/send.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/net/rds/send.c b/net/rds/send.c index acad04243b41..94c7f74909be 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2006 Oracle. All rights reserved. + * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU @@ -1017,10 +1017,15 @@ static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn) if (conn->c_npaths == 0 && hash != 0) { rds_send_ping(conn, 0); - if (conn->c_npaths == 0) { - wait_event_interruptible(conn->c_hs_waitq, - (conn->c_npaths != 0)); - } + /* The underlying connection is not up yet. Need to wait + * until it is up to be sure that the non-zero c_path can be + * used. But if we are interrupted, we have to use the zero + * c_path in case the connection ends up being non-MP capable. + */ + if (conn->c_npaths == 0) + if (wait_event_interruptible(conn->c_hs_waitq, + conn->c_npaths != 0)) + hash = 0; if (conn->c_npaths == 1) hash = 0; } |