net/smc: improve termination processing

Add helper smcr_lgr_link_deactivate_all() and eliminate duplicate code.
In smc_lgr_free(), clear the smc-r links before smc_lgr_free_bufs() is
called so buffers are already prepared for free. The usage of the soft
parameter in __smc_lgr_terminate() is no longer needed, smc_lgr_free()
can be called directly. smc_lgr_terminate_sched() and
smc_smcd_terminate() set lgr->freeing to indicate that the link group
will be freed soon to avoid unnecessary schedules of the free worker.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-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 b6f93b44f9c7cc8444e07611225bc9d63d0c20b2..fb391bc6781ea623382753501f5bc98cdfba698c 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -237,6 +237,19 @@ void smc_lgr_cleanup_early(struct smc_connection *conn)
        smc_lgr_schedule_free_work_fast(lgr);
 }
 
+static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
+{
+       int i;
+
+       for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+               struct smc_link *lnk = &lgr->lnk[i];
+
+               if (smc_link_usable(lnk))
+                       lnk->state = SMC_LNK_INACTIVE;
+       }
+       wake_up_interruptible_all(&lgr->llc_waiter);
+}
+
 static void smc_lgr_free(struct smc_link_group *lgr);
 
 static void smc_lgr_free_work(struct work_struct *work)
@@ -246,7 +259,6 @@ static void smc_lgr_free_work(struct work_struct *work)
                                                  free_work);
        spinlock_t *lgr_lock;
        bool conns;
-       int i;
 
        smc_lgr_list_head(lgr, &lgr_lock);
        spin_lock_bh(lgr_lock);
@@ -271,15 +283,8 @@ static void smc_lgr_free_work(struct work_struct *work)
                                             SMC_LLC_DEL_PROG_INIT_TERM);
        if (lgr->is_smcd && !lgr->terminating)
                smc_ism_signal_shutdown(lgr);
-       if (!lgr->is_smcd) {
-               for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
-                       struct smc_link *lnk = &lgr->lnk[i];
-
-                       if (smc_link_usable(lnk))
-                               lnk->state = SMC_LNK_INACTIVE;
-               }
-               wake_up_interruptible_all(&lgr->llc_waiter);
-       }
+       if (!lgr->is_smcd)
+               smcr_lgr_link_deactivate_all(lgr);
        smc_lgr_free(lgr);
 }
 
@@ -802,6 +807,16 @@ static void smc_lgr_free(struct smc_link_group *lgr)
 {
        int i;
 
+       if (!lgr->is_smcd) {
+               mutex_lock(&lgr->llc_conf_mutex);
+               for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+                       if (lgr->lnk[i].state != SMC_LNK_UNUSED)
+                               smcr_link_clear(&lgr->lnk[i]);
+               }
+               mutex_unlock(&lgr->llc_conf_mutex);
+               smc_llc_lgr_clear(lgr);
+       }
+
        smc_lgr_free_bufs(lgr);
        if (lgr->is_smcd) {
                if (!lgr->terminating) {
@@ -811,11 +826,6 @@ static void smc_lgr_free(struct smc_link_group *lgr)
                if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
                        wake_up(&lgr->smcd->lgrs_deleted);
        } else {
-               for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
-                       if (lgr->lnk[i].state != SMC_LNK_UNUSED)
-                               smcr_link_clear(&lgr->lnk[i]);
-               }
-               smc_llc_lgr_clear(lgr);
                if (!atomic_dec_return(&lgr_cnt))
                        wake_up(&lgrs_deleted);
        }
@@ -870,8 +880,6 @@ static void smc_conn_kill(struct smc_connection *conn, bool soft)
 
 static void smc_lgr_cleanup(struct smc_link_group *lgr)
 {
-       int i;
-
        if (lgr->is_smcd) {
                smc_ism_signal_shutdown(lgr);
                smcd_unregister_all_dmbs(lgr);
@@ -883,13 +891,7 @@ static void smc_lgr_cleanup(struct smc_link_group *lgr)
                if (!rsn)
                        rsn = SMC_LLC_DEL_PROG_INIT_TERM;
                smc_llc_send_link_delete_all(lgr, false, rsn);
-               for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
-                       struct smc_link *lnk = &lgr->lnk[i];
-
-                       if (smc_link_usable(lnk))
-                               lnk->state = SMC_LNK_INACTIVE;
-               }
-               wake_up_interruptible_all(&lgr->llc_waiter);
+               smcr_lgr_link_deactivate_all(lgr);
        }
 }
 
@@ -905,8 +907,8 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
 
        if (lgr->terminating)
                return; /* lgr already terminating */
-       if (!soft)
-               cancel_delayed_work_sync(&lgr->free_work);
+       /* cancel free_work sync, will terminate when lgr->freeing is set */
+       cancel_delayed_work_sync(&lgr->free_work);
        lgr->terminating = 1;
 
        /* kill remaining link group connections */
@@ -926,10 +928,7 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
        }
        read_unlock_bh(&lgr->conns_lock);
        smc_lgr_cleanup(lgr);
-       if (soft)
-               smc_lgr_schedule_free_work_fast(lgr);
-       else
-               smc_lgr_free(lgr);
+       smc_lgr_free(lgr);
 }
 
 /* unlink link group and schedule termination */
@@ -944,6 +943,7 @@ void smc_lgr_terminate_sched(struct smc_link_group *lgr)
                return; /* lgr already terminating */
        }
        list_del_init(&lgr->list);
+       lgr->freeing = 1;
        spin_unlock_bh(lgr_lock);
        schedule_work(&lgr->terminate_work);
 }
@@ -962,6 +962,7 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
                        if (peer_gid) /* peer triggered termination */
                                lgr->peer_shutdown = 1;
                        list_move(&lgr->list, &lgr_free_list);
+                       lgr->freeing = 1;
                }
        }
        spin_unlock_bh(&dev->lgr_lock);