net/smc: fix smc_buf_unuse to use the lgr pointer

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>

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index e871368..18daebc 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -122,22 +122,17 @@ static void __smc_lgr_unregister_conn(struct smc_connection *conn)
        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_connection *conn)
                        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_connection *conn)
 /* 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)