net/smc: wait for tx completions before link freeing

Make sure all pending work requests are completed before freeing
a link.
Dismiss tx pending slots already when terminating a link group to
exploit termination shortcut in tx completion queue handler.

And kill the completion queue tasklets after destroy of the
completion queues, otherwise there is a time window for another
tasklet schedule of an already killed tasklet.

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>

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index ee44e82..0755bd4 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -548,6 +548,8 @@ static void smc_conn_kill(struct smc_connection *conn, bool soft)
                        tasklet_kill(&conn->rx_tsklet);
                else
                        tasklet_unlock_wait(&conn->rx_tsklet);
+       } else {
+               smc_cdc_tx_dismiss_slots(conn);
        }
        smc_lgr_unregister_conn(conn);
        smc_close_active_abort(smc);

diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index af05dae..c15dcd0 100644 (file)
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -520,9 +520,9 @@ static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
        if (!smcibdev->initialized)
                return;
        smcibdev->initialized = 0;
-       smc_wr_remove_dev(smcibdev);
        ib_destroy_cq(smcibdev->roce_cq_recv);
        ib_destroy_cq(smcibdev->roce_cq_send);
+       smc_wr_remove_dev(smcibdev);
 }
 
 static struct ib_client smc_ib_client;

diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index 619dd89..337ee52 100644 (file)
--- a/net/smc/smc_wr.c
+++ b/net/smc/smc_wr.c
@@ -50,6 +50,26 @@ struct smc_wr_tx_pend {      /* control data for a pending send request */
 
 /*------------------------------- completion --------------------------------*/
 
+/* returns true if at least one tx work request is pending on the given link */
+static inline bool smc_wr_is_tx_pend(struct smc_link *link)
+{
+       if (find_first_bit(link->wr_tx_mask, link->wr_tx_cnt) !=
+                                                       link->wr_tx_cnt) {
+               return true;
+       }
+       return false;
+}
+
+/* wait till all pending tx work requests on the given link are completed */
+static inline int smc_wr_tx_wait_no_pending_sends(struct smc_link *link)
+{
+       if (wait_event_timeout(link->wr_tx_wait, !smc_wr_is_tx_pend(link),
+                              SMC_WR_TX_WAIT_PENDING_TIME))
+               return 0;
+       else /* timeout */
+               return -EPIPE;
+}
+
 static inline int smc_wr_tx_find_pending_index(struct smc_link *link, u64 wr_id)
 {
        u32 i;
@@ -229,6 +249,7 @@ int smc_wr_tx_put_slot(struct smc_link *link,
                memset(&link->wr_tx_bufs[idx], 0,
                       sizeof(link->wr_tx_bufs[idx]));
                test_and_clear_bit(idx, link->wr_tx_mask);
+               wake_up(&link->wr_tx_wait);
                return 1;
        }
 
@@ -512,8 +533,10 @@ void smc_wr_free_link(struct smc_link *lnk)
 {
        struct ib_device *ibdev;
 
-       memset(lnk->wr_tx_mask, 0,
-              BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
+       if (smc_wr_tx_wait_no_pending_sends(lnk))
+               memset(lnk->wr_tx_mask, 0,
+                      BITS_TO_LONGS(SMC_WR_BUF_CNT) *
+                                               sizeof(*lnk->wr_tx_mask));
 
        if (!lnk->smcibdev)
                return;