net/smc: fix cleanup for linkgroup setup failures

If an SMC connection to a certain peer is setup the first time,
a new linkgroup is created. In case of setup failures, such a
linkgroup is unusable and should disappear. As a first step the
linkgroup is removed from the linkgroup list in smc_lgr_forget().

There are 2 problems:
smc_listen_decline() might be called before linkgroup creation
resulting in a crash due to calling smc_lgr_forget() with
parameter NULL.
If a setup failure occurs after linkgroup creation, the connection
is never unregistered from the linkgroup, preventing linkgroup
freeing.

This patch introduces an enhanced smc_lgr_cleanup_early() function
which
* contains a linkgroup check for early smc_listen_decline()
  invocations
* invokes smc_conn_free() to guarantee unregistering of the
  connection.
* schedules fast linkgroup removal of the unusable linkgroup

And the unused function smcd_conn_free() is removed from smc_core.h.

Fixes: 3b2dec2603d5b ("net/smc: restructure client and server code in af_smc")
Fixes: 2a0674fffb6bc ("net/smc: improve abnormal termination of link groups")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index c472e12951d1..234ae25f0025 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -296,6 +296,7 @@ struct smc_clc_msg_accept_confirm;
 struct smc_clc_msg_local;
 
 void smc_lgr_forget(struct smc_link_group *lgr);
+void smc_lgr_cleanup_early(struct smc_connection *conn);
 void smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
@@ -316,7 +317,6 @@ int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini);
 
 void smc_conn_free(struct smc_connection *conn);
 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini);
-void smcd_conn_free(struct smc_connection *conn);
 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
 int smc_core_init(void);
 void smc_core_exit(void);