4.19-stable review patch. If anyone has any objections, please let me know.
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From: Karsten Graul kgraul@linux.ibm.com
[ Upstream commit fb692ec4117f6fd25044cfb5720d6b79d400dc65 ]
The pointer to the link group is unset in the smc connection structure right before the call to smc_buf_unuse. Provide the lgr pointer to smc_buf_unuse explicitly. And move the call to smc_lgr_schedule_free_work to the end of smc_conn_free.
Fixes: a6920d1d130c ("net/smc: handle unregistered buffers") Signed-off-by: Karsten Graul kgraul@linux.ibm.com Signed-off-by: Ursula Braun ubraun@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/smc/smc_core.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)
--- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -122,22 +122,17 @@ static void __smc_lgr_unregister_conn(st sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */ }
-/* Unregister connection and trigger lgr freeing if applicable +/* Unregister connection from lgr */ static void smc_lgr_unregister_conn(struct smc_connection *conn) { struct smc_link_group *lgr = conn->lgr; - int reduced = 0;
write_lock_bh(&lgr->conns_lock); if (conn->alert_token_local) { - reduced = 1; __smc_lgr_unregister_conn(conn); } write_unlock_bh(&lgr->conns_lock); - if (!reduced || lgr->conns_num) - return; - smc_lgr_schedule_free_work(lgr); }
/* Send delete link, either as client to request the initiation @@ -291,7 +286,8 @@ out: return rc; }
-static void smc_buf_unuse(struct smc_connection *conn) +static void smc_buf_unuse(struct smc_connection *conn, + struct smc_link_group *lgr) { if (conn->sndbuf_desc) conn->sndbuf_desc->used = 0; @@ -301,8 +297,6 @@ static void smc_buf_unuse(struct smc_con conn->rmb_desc->used = 0; } else { /* buf registration failed, reuse not possible */ - struct smc_link_group *lgr = conn->lgr; - write_lock_bh(&lgr->rmbs_lock); list_del(&conn->rmb_desc->list); write_unlock_bh(&lgr->rmbs_lock); @@ -315,16 +309,21 @@ static void smc_buf_unuse(struct smc_con /* remove a finished connection from its link group */ void smc_conn_free(struct smc_connection *conn) { - if (!conn->lgr) + struct smc_link_group *lgr = conn->lgr; + + if (!lgr) return; - if (conn->lgr->is_smcd) { + if (lgr->is_smcd) { smc_ism_unset_conn(conn); tasklet_kill(&conn->rx_tsklet); } else { smc_cdc_tx_dismiss_slots(conn); } - smc_lgr_unregister_conn(conn); - smc_buf_unuse(conn); + smc_lgr_unregister_conn(conn); /* unsets conn->lgr */ + smc_buf_unuse(conn, lgr); /* allow buffer reuse */ + + if (!lgr->conns_num) + smc_lgr_schedule_free_work(lgr); }
static void smc_link_clear(struct smc_link *lnk)