From: Ursula Braun ubraun@linux.ibm.com
commit 51e3dfa8906ace90c809235b3d3afebc166b6433 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/smc/af_smc.c | 25 +++++++++++++++---------- net/smc/smc_core.c | 12 ++++++++++++ net/smc/smc_core.h | 2 +- 3 files changed, 28 insertions(+), 11 deletions(-)
--- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -512,15 +512,18 @@ static int smc_connect_decline_fallback( static int smc_connect_abort(struct smc_sock *smc, int reason_code, int local_contact) { + bool is_smcd = smc->conn.lgr->is_smcd; + if (local_contact == SMC_FIRST_CONTACT) - smc_lgr_forget(smc->conn.lgr); - if (smc->conn.lgr->is_smcd) + smc_lgr_cleanup_early(&smc->conn); + else + smc_conn_free(&smc->conn); + if (is_smcd) /* there is only one lgr role for SMC-D; use server lock */ mutex_unlock(&smc_server_lgr_pending); else mutex_unlock(&smc_client_lgr_pending);
- smc_conn_free(&smc->conn); smc->connect_nonblock = 0; return reason_code; } @@ -1091,7 +1094,6 @@ static void smc_listen_out_err(struct sm if (newsmcsk->sk_state == SMC_INIT) sock_put(&new_smc->sk); /* passive closing */ newsmcsk->sk_state = SMC_CLOSED; - smc_conn_free(&new_smc->conn);
smc_listen_out(new_smc); } @@ -1102,12 +1104,13 @@ static void smc_listen_decline(struct sm { /* RDMA setup failed, switch back to TCP */ if (local_contact == SMC_FIRST_CONTACT) - smc_lgr_forget(new_smc->conn.lgr); + smc_lgr_cleanup_early(&new_smc->conn); + else + smc_conn_free(&new_smc->conn); if (reason_code < 0) { /* error, no fallback possible */ smc_listen_out_err(new_smc); return; } - smc_conn_free(&new_smc->conn); smc_switch_to_fallback(new_smc); new_smc->fallback_rsn = reason_code; if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) { @@ -1170,16 +1173,18 @@ static int smc_listen_ism_init(struct sm new_smc->conn.lgr->vlan_id, new_smc->conn.lgr->smcd)) { if (ini->cln_first_contact == SMC_FIRST_CONTACT) - smc_lgr_forget(new_smc->conn.lgr); - smc_conn_free(&new_smc->conn); + smc_lgr_cleanup_early(&new_smc->conn); + else + smc_conn_free(&new_smc->conn); return SMC_CLC_DECL_SMCDNOTALK; }
/* Create send and receive buffers */ if (smc_buf_create(new_smc, true)) { if (ini->cln_first_contact == SMC_FIRST_CONTACT) - smc_lgr_forget(new_smc->conn.lgr); - smc_conn_free(&new_smc->conn); + smc_lgr_cleanup_early(&new_smc->conn); + else + smc_conn_free(&new_smc->conn); return SMC_CLC_DECL_MEM; }
--- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -162,6 +162,18 @@ static void smc_lgr_unregister_conn(stru conn->lgr = NULL; }
+void smc_lgr_cleanup_early(struct smc_connection *conn) +{ + struct smc_link_group *lgr = conn->lgr; + + if (!lgr) + return; + + smc_conn_free(conn); + smc_lgr_forget(lgr); + smc_lgr_schedule_free_work_fast(lgr); +} + /* Send delete link, either as client to request the initiation * of the DELETE LINK sequence from server; or as server to * initiate the delete processing. See smc_llc_rx_delete_link(). --- 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 *clc
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);