[PATCH net-next 09/13] net/smc: llc_del_link_work and use the LLC flow for delete link

Karsten Graul
2020-05-02T12:36:18Z

Introduce a work that is scheduled when a new DELETE_LINK LLC request is
received. The work will call either the SMC client or SMC server
DELETE_LINK processing.
And use the LLC flow framework to process incoming DELETE_LINK LLC
messages, scheduling the llc_del_link_work for those events.
With these changes smc_lgr_forget() is only called by one function and
can be migrated into smc_lgr_cleanup_early().

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
---
net/smc/smc_core.c | 22 +++++++------------
net/smc/smc_core.h | 2 +-
net/smc/smc_llc.c | 55 ++++++++++++++++++++++++++++++----------------
3 files changed, 45 insertions(+), 34 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 2f8faa9c9e8e..a964304283fa 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -193,12 +193,19 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn)
void smc_lgr_cleanup_early(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
+ struct list_head *lgr_list;
+ spinlock_t *lgr_lock;

if (!lgr)
return;

smc_conn_free(conn);
- smc_lgr_forget(lgr);
+ lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
+ spin_lock_bh(lgr_lock);
+ /* do not use this link group for new connections */
+ if (!list_empty(lgr_list))
+ list_del_init(lgr_list);
+ spin_unlock_bh(lgr_lock);
smc_lgr_schedule_free_work_fast(lgr);
}

@@ -653,19 +660,6 @@ static void smc_lgr_free(struct smc_link_group *lgr)
kfree(lgr);
}

-void smc_lgr_forget(struct smc_link_group *lgr)
-{
- struct list_head *lgr_list;
- spinlock_t *lgr_lock;
-
- lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
- spin_lock_bh(lgr_lock);
- /* do not use this link group for new connections */
- if (!list_empty(lgr_list))
- list_del_init(lgr_list);
- spin_unlock_bh(lgr_lock);
-}
-
static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
{
int i;
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 4e00819e2db7..7fe53feb9dc4 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -254,6 +254,7 @@ struct smc_link_group {
struct mutex llc_conf_mutex;
/* protects lgr reconfig. */
struct work_struct llc_add_link_work;
+ struct work_struct llc_del_link_work;
struct work_struct llc_event_work;
/* llc event worker */
wait_queue_head_t llc_waiter;
@@ -343,7 +344,6 @@ struct smc_sock;
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_sched(struct smc_link_group *lgr);
void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport);
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 9d102c912be9..e4e3910a9624 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -1118,22 +1118,18 @@ static void smc_llc_add_link_work(struct work_struct *work)
smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
}

-static void smc_llc_rx_delete_link(struct smc_link *link,
- struct smc_llc_msg_del_link *llc)
+static void smc_llc_delete_link_work(struct work_struct *work)
{
- struct smc_link_group *lgr = smc_get_lgr(link);
+ struct smc_link_group *lgr = container_of(work, struct smc_link_group,
+ llc_del_link_work);

- smc_lgr_forget(lgr);
- if (lgr->role == SMC_SERV) {
- /* client asks to delete this link, send request */
- smc_llc_send_delete_link(link, 0, SMC_LLC_REQ, true,
- SMC_LLC_DEL_PROG_INIT_TERM);
- } else {
- /* server requests to delete this link, send response */
- smc_llc_send_delete_link(link, 0, SMC_LLC_RESP, true,
- SMC_LLC_DEL_PROG_INIT_TERM);
+ if (list_empty(&lgr->list)) {
+ /* link group is terminating */
+ smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
+ goto out;
}
- smcr_link_down_cond(link);
+out:
+ smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
}

/* process a confirm_rkey request from peer, remote flow */
@@ -1255,8 +1251,30 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
}
break;
case SMC_LLC_DELETE_LINK:
- smc_llc_rx_delete_link(link, &llc->delete_link);
- break;
+ if (lgr->role == SMC_CLNT) {
+ /* server requests to delete this link, send response */
+ if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
+ /* DEL LINK REQ during ADD LINK SEQ */
+ smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
+ qentry);
+ wake_up_interruptible(&lgr->llc_waiter);
+ } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
+ qentry)) {
+ schedule_work(&lgr->llc_del_link_work);
+ }
+ } else {
+ if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
+ !lgr->llc_flow_lcl.qentry) {
+ /* DEL LINK REQ during ADD LINK SEQ */
+ smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
+ qentry);
+ wake_up_interruptible(&lgr->llc_waiter);
+ } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
+ qentry)) {
+ schedule_work(&lgr->llc_del_link_work);
+ }
+ }
+ return;
case SMC_LLC_CONFIRM_RKEY:
/* new request from remote, assign to remote flow */
if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
@@ -1325,6 +1343,7 @@ static void smc_llc_rx_response(struct smc_link *link,
complete(&link->llc_testlink_resp);
break;
case SMC_LLC_ADD_LINK:
+ case SMC_LLC_DELETE_LINK:
case SMC_LLC_CONFIRM_LINK:
case SMC_LLC_ADD_LINK_CONT:
case SMC_LLC_CONFIRM_RKEY:
@@ -1333,10 +1352,6 @@ static void smc_llc_rx_response(struct smc_link *link,
smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
wake_up_interruptible(&link->lgr->llc_waiter);
return;
- case SMC_LLC_DELETE_LINK:
- if (link->lgr->role == SMC_SERV)
- smc_lgr_schedule_free_work_fast(link->lgr);
- break;
case SMC_LLC_CONFIRM_RKEY_CONT:
/* not used because max links is 3 */
break;
@@ -1424,6 +1439,7 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)

INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
+ INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
INIT_LIST_HEAD(&lgr->llc_event_q);
spin_lock_init(&lgr->llc_event_q_lock);
spin_lock_init(&lgr->llc_flow_lock);
@@ -1439,6 +1455,7 @@ void smc_llc_lgr_clear(struct smc_link_group *lgr)
wake_up_interruptible_all(&lgr->llc_waiter);
cancel_work_sync(&lgr->llc_event_work);
cancel_work_sync(&lgr->llc_add_link_work);
+ cancel_work_sync(&lgr->llc_del_link_work);
if (lgr->delayed_event) {
kfree(lgr->delayed_event);
lgr->delayed_event = NULL;
--
2.17.1