[PATCH net-next 3/8] net/smc: abnormal termination of SMCD link groups

Karsten Graul
2019-11-14T12:02:42Z

A final cleanup due to SMCD device removal means immediate freeing
of all link groups belonging to this device in interrupt context.

This patch introduces a separate SMCD link group termination routine,
which terminates all link groups of an SMCD device.

This new routine smcd_terminate_all ()is reused if the smc module is
unloaded.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/smc_clc.c | 2 +-
net/smc/smc_core.c | 67 +++++++++++++++++++++++++++++++++++-----------
net/smc/smc_core.h | 3 ++-
net/smc/smc_ism.c | 2 +-
net/smc/smc_llc.c | 2 +-
net/smc/smc_tx.c | 2 +-
6 files changed, 57 insertions(+), 21 deletions(-)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 49bcebff6378..0879f7bed967 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -349,7 +349,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
smc->conn.lgr->sync_err = 1;
- smc_lgr_terminate(smc->conn.lgr);
+ smc_lgr_terminate(smc->conn.lgr, true);
}
}

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 9d6da2c7413d..d79dd78c1cd8 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -224,7 +224,7 @@ static void smc_lgr_terminate_work(struct work_struct *work)
struct smc_link_group *lgr = container_of(work, struct smc_link_group,
terminate_work);

- smc_lgr_terminate(lgr);
+ smc_lgr_terminate(lgr, true);
}

/* create a new SMC link group */
@@ -528,7 +528,7 @@ static void smc_sk_wake_ups(struct smc_sock *smc)
}

/* kill a connection */
-static void smc_conn_kill(struct smc_connection *conn)
+static void smc_conn_kill(struct smc_connection *conn, bool soft)
{
struct smc_sock *smc = container_of(conn, struct smc_sock, conn);

@@ -541,7 +541,10 @@ static void smc_conn_kill(struct smc_connection *conn)
smc_sk_wake_ups(smc);
if (conn->lgr->is_smcd) {
smc_ism_unset_conn(conn);
- tasklet_kill(&conn->rx_tsklet);
+ if (soft)
+ tasklet_kill(&conn->rx_tsklet);
+ else
+ tasklet_unlock_wait(&conn->rx_tsklet);
}
smc_lgr_unregister_conn(conn);
smc_close_active_abort(smc);
@@ -562,7 +565,7 @@ static void smc_lgr_cleanup(struct smc_link_group *lgr)
}

/* terminate link group */
-static void __smc_lgr_terminate(struct smc_link_group *lgr)
+static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
{
struct smc_connection *conn;
struct smc_sock *smc;
@@ -570,6 +573,8 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr)

if (lgr->terminating)
return; /* lgr already terminating */
+ if (!soft)
+ cancel_delayed_work_sync(&lgr->free_work);
lgr->terminating = 1;
if (!lgr->is_smcd)
smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
@@ -583,7 +588,7 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr)
smc = container_of(conn, struct smc_sock, conn);
sock_hold(&smc->sk); /* sock_put below */
lock_sock(&smc->sk);
- smc_conn_kill(conn);
+ smc_conn_kill(conn, soft);
release_sock(&smc->sk);
sock_put(&smc->sk); /* sock_hold above */
read_lock_bh(&lgr->conns_lock);
@@ -591,11 +596,17 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr)
}
read_unlock_bh(&lgr->conns_lock);
smc_lgr_cleanup(lgr);
- smc_lgr_schedule_free_work_fast(lgr);
+ if (soft)
+ smc_lgr_schedule_free_work_fast(lgr);
+ else
+ smc_lgr_free(lgr);
}

-/* unlink and terminate link group */
-void smc_lgr_terminate(struct smc_link_group *lgr)
+/* unlink and terminate link group
+ * @soft: true if link group shutdown can take its time
+ * false if immediate link group shutdown is required
+ */
+void smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
{
spinlock_t *lgr_lock;

@@ -605,9 +616,11 @@ void smc_lgr_terminate(struct smc_link_group *lgr)
spin_unlock_bh(lgr_lock);
return; /* lgr already terminating */
}
+ if (!soft)
+ lgr->freeing = 1;
list_del_init(&lgr->list);
spin_unlock_bh(lgr_lock);
- __smc_lgr_terminate(lgr);
+ __smc_lgr_terminate(lgr, soft);
}

/* Called when IB port is terminated */
@@ -627,11 +640,11 @@ void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)

list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
list_del_init(&lgr->list);
- __smc_lgr_terminate(lgr);
+ __smc_lgr_terminate(lgr, true);
}
}

-/* Called when SMC-D device is terminated or peer is lost */
+/* Called when peer lgr shutdown (regularly or abnormally) is received */
void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
{
struct smc_link_group *lgr, *l;
@@ -656,6 +669,24 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
}
}

+/* Called when an SMCD device is removed or the smc module is unloaded */
+void smc_smcd_terminate_all(struct smcd_dev *smcd)
+{
+ struct smc_link_group *lgr, *lg;
+ LIST_HEAD(lgr_free_list);
+
+ spin_lock_bh(&smcd->lgr_lock);
+ list_splice_init(&smcd->lgr_list, &lgr_free_list);
+ list_for_each_entry(lgr, &lgr_free_list, list)
+ lgr->freeing = 1;
+ spin_unlock_bh(&smcd->lgr_lock);
+
+ list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
+ list_del_init(&lgr->list);
+ __smc_lgr_terminate(lgr, false);
+ }
+}
+
/* Determine vlan of internal TCP socket.
* @vlan_id: address to store the determined vlan id into
*/
@@ -1173,8 +1204,8 @@ static void smc_core_going_away(void)
spin_unlock(&smcd_dev_list.lock);
}

-/* Called (from smc_exit) when module is removed */
-void smc_core_exit(void)
+/* Clean up all SMC link groups */
+static void smc_lgrs_shutdown(void)
{
struct smc_link_group *lgr, *lg;
LIST_HEAD(lgr_freeing_list);
@@ -1188,7 +1219,7 @@ void smc_core_exit(void)

spin_lock(&smcd_dev_list.lock);
list_for_each_entry(smcd, &smcd_dev_list.list, list)
- list_splice_init(&smcd->lgr_list, &lgr_freeing_list);
+ smc_smcd_terminate_all(smcd);
spin_unlock(&smcd_dev_list.lock);

list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
@@ -1202,8 +1233,12 @@ void smc_core_exit(void)
smc_llc_link_inactive(lnk);
}
cancel_delayed_work_sync(&lgr->free_work);
- if (lgr->is_smcd)
- smc_ism_signal_shutdown(lgr);
smc_lgr_free(lgr); /* free link group */
}
}
+
+/* Called (from smc_exit) when module is removed */
+void smc_core_exit(void)
+{
+ smc_lgrs_shutdown();
+}
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 097ceba86caf..7f34f4d5a514 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -296,10 +296,11 @@ struct smc_clc_msg_accept_confirm;
struct smc_clc_msg_local;

void smc_lgr_forget(struct smc_link_group *lgr);
-void smc_lgr_terminate(struct smc_link_group *lgr);
+void smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
unsigned short vlan);
+void smc_smcd_terminate_all(struct smcd_dev *dev);
int smc_buf_create(struct smc_sock *smc, bool is_smcd);
int smc_uncompress_bufsize(u8 compressed);
int smc_rmb_rtoken_handling(struct smc_connection *conn,
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 903da947b20d..56cdab8be1fa 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -329,7 +329,7 @@ void smcd_unregister_dev(struct smcd_dev *smcd)
list_del_init(&smcd->list);
spin_unlock(&smcd_dev_list.lock);
smcd->going_away = 1;
- smc_smcd_terminate(smcd, 0, VLAN_VID_MASK);
+ smc_smcd_terminate_all(smcd);
flush_workqueue(smcd->event_wq);
destroy_workqueue(smcd->event_wq);

diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index e1918ffaf125..26a18c872455 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -614,7 +614,7 @@ static void smc_llc_testlink_work(struct work_struct *work)
rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
SMC_LLC_WAIT_TIME);
if (rc <= 0) {
- smc_lgr_terminate(smc_get_lgr(link));
+ smc_lgr_terminate(smc_get_lgr(link), true);
return;
}
next_interval = link->llc_testlink_time;
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index 824f096ee7de..0d42e7716b91 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -284,7 +284,7 @@ static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset,
rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey;
rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL);
if (rc)
- smc_lgr_terminate(lgr);
+ smc_lgr_terminate(lgr, true);
return rc;
}

--
2.17.1