[PATCH net-next 2/8] net/smc: immediate termination for SMCD link groups

Karsten Graul
2019-11-14T12:03:00Z

SMCD link group termination is called when peer signals its shutdown
of its corresponding link group. For regular shutdowns no connections
exist anymore. For abnormal shutdowns connections must be killed and
their DMBs must be unregistered immediately. That means the SMCR method
to delay the link group freeing several seconds does not fit.

This patch adds immediate termination of a link group and its SMCD
connections and makes sure all SMCD link group related cleanup steps
are finished.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
drivers/s390/net/ism.h | 2 --
include/net/smc.h | 2 ++
net/smc/smc_close.c | 25 +++++++++++++++++------
net/smc/smc_core.c | 46 +++++++++++++++++++++++++++++++++++-------
net/smc/smc_ism.c | 14 +++++++++++--
5 files changed, 72 insertions(+), 17 deletions(-)

diff --git a/drivers/s390/net/ism.h b/drivers/s390/net/ism.h
index 66eac2b9704d..1901e9c80ed8 100644
--- a/drivers/s390/net/ism.h
+++ b/drivers/s390/net/ism.h
@@ -32,8 +32,6 @@
#define ISM_UNREG_SBA 0x11
#define ISM_UNREG_IEQ 0x12

-#define ISM_ERROR 0xFFFF
-
struct ism_req_hdr {
u32 cmd;
u16 : 16;
diff --git a/include/net/smc.h b/include/net/smc.h
index 05174ae4f325..7c2082341bb3 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -37,6 +37,8 @@ struct smcd_dmb {
#define ISM_EVENT_GID 1
#define ISM_EVENT_SWR 2

+#define ISM_ERROR 0xFFFF
+
struct smcd_event {
u32 type;
u32 code;
diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index d34e5adce2eb..d205b2114006 100644
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -110,6 +110,17 @@ int smc_close_abort(struct smc_connection *conn)
return smc_cdc_get_slot_and_msg_send(conn);
}

+static void smc_close_cancel_work(struct smc_sock *smc)
+{
+ struct sock *sk = &smc->sk;
+
+ release_sock(sk);
+ cancel_work_sync(&smc->conn.close_work);
+ cancel_delayed_work_sync(&smc->conn.tx_work);
+ lock_sock(sk);
+ sk->sk_state = SMC_CLOSED;
+}
+
/* terminate smc socket abnormally - active abort
* link group is terminated, i.e. RDMA communication no longer possible
*/
@@ -126,23 +137,21 @@ void smc_close_active_abort(struct smc_sock *smc)
switch (sk->sk_state) {
case SMC_ACTIVE:
sk->sk_state = SMC_PEERABORTWAIT;
- release_sock(sk);
- cancel_delayed_work_sync(&smc->conn.tx_work);
- lock_sock(sk);
+ smc_close_cancel_work(smc);
sk->sk_state = SMC_CLOSED;
sock_put(sk); /* passive closing */
break;
case SMC_APPCLOSEWAIT1:
case SMC_APPCLOSEWAIT2:
- release_sock(sk);
- cancel_delayed_work_sync(&smc->conn.tx_work);
- lock_sock(sk);
+ smc_close_cancel_work(smc);
sk->sk_state = SMC_CLOSED;
sock_put(sk); /* postponed passive closing */
break;
case SMC_PEERCLOSEWAIT1:
case SMC_PEERCLOSEWAIT2:
case SMC_PEERFINCLOSEWAIT:
+ sk->sk_state = SMC_PEERABORTWAIT;
+ smc_close_cancel_work(smc);
sk->sk_state = SMC_CLOSED;
smc_conn_free(&smc->conn);
release_clcsock = true;
@@ -150,7 +159,11 @@ void smc_close_active_abort(struct smc_sock *smc)
break;
case SMC_PROCESSABORT:
case SMC_APPFINCLOSEWAIT:
+ sk->sk_state = SMC_PEERABORTWAIT;
+ smc_close_cancel_work(smc);
sk->sk_state = SMC_CLOSED;
+ smc_conn_free(&smc->conn);
+ release_clcsock = true;
break;
case SMC_INIT:
case SMC_PEERABORTWAIT:
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 561f069b30de..9d6da2c7413d 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -214,7 +214,7 @@ static void smc_lgr_free_work(struct work_struct *work)

if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
smc_llc_link_inactive(lnk);
- if (lgr->is_smcd)
+ if (lgr->is_smcd && !lgr->terminating)
smc_ism_signal_shutdown(lgr);
smc_lgr_free(lgr);
}
@@ -381,7 +381,8 @@ void smc_conn_free(struct smc_connection *conn)
if (!lgr)
return;
if (lgr->is_smcd) {
- smc_ism_unset_conn(conn);
+ if (!list_empty(&lgr->list))
+ smc_ism_unset_conn(conn);
tasklet_kill(&conn->rx_tsklet);
} else {
smc_cdc_tx_dismiss_slots(conn);
@@ -481,8 +482,10 @@ static void smc_lgr_free(struct smc_link_group *lgr)
{
smc_lgr_free_bufs(lgr);
if (lgr->is_smcd) {
- smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
- put_device(&lgr->smcd->dev);
+ if (!lgr->terminating) {
+ smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
+ put_device(&lgr->smcd->dev);
+ }
} else {
smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
put_device(&lgr->lnk[SMC_SINGLE_LINK].smcibdev->ibdev->dev);
@@ -503,6 +506,20 @@ void smc_lgr_forget(struct smc_link_group *lgr)
spin_unlock_bh(lgr_lock);
}

+static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
+{
+ int i;
+
+ for (i = 0; i < SMC_RMBE_SIZES; i++) {
+ struct smc_buf_desc *buf_desc;
+
+ list_for_each_entry(buf_desc, &lgr->rmbs[i], list) {
+ buf_desc->len += sizeof(struct smcd_cdc_msg);
+ smc_ism_unregister_dmb(lgr->smcd, buf_desc);
+ }
+ }
+}
+
static void smc_sk_wake_ups(struct smc_sock *smc)
{
smc->sk.sk_write_space(&smc->sk);
@@ -522,12 +539,28 @@ static void smc_conn_kill(struct smc_connection *conn)
conn->killed = 1;
smc->sk.sk_err = ECONNABORTED;
smc_sk_wake_ups(smc);
- if (conn->lgr->is_smcd)
+ if (conn->lgr->is_smcd) {
+ smc_ism_unset_conn(conn);
tasklet_kill(&conn->rx_tsklet);
+ }
smc_lgr_unregister_conn(conn);
smc_close_active_abort(smc);
}

+static void smc_lgr_cleanup(struct smc_link_group *lgr)
+{
+ if (lgr->is_smcd) {
+ smc_ism_signal_shutdown(lgr);
+ smcd_unregister_all_dmbs(lgr);
+ smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
+ put_device(&lgr->smcd->dev);
+ } else {
+ struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
+
+ wake_up(&lnk->wr_reg_wait);
+ }
+}
+
/* terminate link group */
static void __smc_lgr_terminate(struct smc_link_group *lgr)
{
@@ -557,8 +590,7 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr)
node = rb_first(&lgr->conns_all);
}
read_unlock_bh(&lgr->conns_lock);
- if (!lgr->is_smcd)
- wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
+ smc_lgr_cleanup(lgr);
smc_lgr_schedule_free_work_fast(lgr);
}

diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 18946e95a3be..903da947b20d 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -146,6 +146,10 @@ int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
{
struct smcd_dmb dmb;
+ int rc = 0;
+
+ if (!dmb_desc->dma_addr)
+ return rc;

memset(&dmb, 0, sizeof(dmb));
dmb.dmb_tok = dmb_desc->token;
@@ -153,7 +157,13 @@ int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
dmb.cpu_addr = dmb_desc->cpu_addr;
dmb.dma_addr = dmb_desc->dma_addr;
dmb.dmb_len = dmb_desc->len;
- return smcd->ops->unregister_dmb(smcd, &dmb);
+ rc = smcd->ops->unregister_dmb(smcd, &dmb);
+ if (!rc || rc == ISM_ERROR) {
+ dmb_desc->cpu_addr = NULL;
+ dmb_desc->dma_addr = 0;
+ }
+
+ return rc;
}

int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
@@ -375,7 +385,7 @@ void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)

spin_lock_irqsave(&smcd->lock, flags);
conn = smcd->conn[dmbno];
- if (conn)
+ if (conn && !conn->killed)
tasklet_schedule(&conn->rx_tsklet);
spin_unlock_irqrestore(&smcd->lock, flags);
}
--
2.17.1