IPoIB/cm: Fix SRQ WR leak
SRQ WR leakage has been observed with IPoIB/CM: e.g. flipping ports on
and off will, with time, leak out all WRs and then all connections
will start getting RNR NAKs. Fix this in the way suggested by spec:
move the QP being destroyed to the error state, wait for "Last WQE
Reached" event and then post WR on a "drain QP" connected to the same
CQ. Once we observe a completion on the drain QP, it's safe to call
ib_destroy_qp.
Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index 93d4a9a1..a0b3782 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -132,12 +132,46 @@
__be32 mtu;
};
+/*
+ * Quoting 10.3.1 Queue Pair and EE Context States:
+ *
+ * Note, for QPs that are associated with an SRQ, the Consumer should take the
+ * QP through the Error State before invoking a Destroy QP or a Modify QP to the
+ * Reset State. The Consumer may invoke the Destroy QP without first performing
+ * a Modify QP to the Error State and waiting for the Affiliated Asynchronous
+ * Last WQE Reached Event. However, if the Consumer does not wait for the
+ * Affiliated Asynchronous Last WQE Reached Event, then WQE and Data Segment
+ * leakage may occur. Therefore, it is good programming practice to tear down a
+ * QP that is associated with an SRQ by using the following process:
+ *
+ * - Put the QP in the Error State
+ * - Wait for the Affiliated Asynchronous Last WQE Reached Event;
+ * - either:
+ * drain the CQ by invoking the Poll CQ verb and either wait for CQ
+ * to be empty or the number of Poll CQ operations has exceeded
+ * CQ capacity size;
+ * - or
+ * post another WR that completes on the same CQ and wait for this
+ * WR to return as a WC;
+ * - and then invoke a Destroy QP or Reset QP.
+ *
+ * We use the second option and wait for a completion on the
+ * rx_drain_qp before destroying QPs attached to our SRQ.
+ */
+
+enum ipoib_cm_state {
+ IPOIB_CM_RX_LIVE,
+ IPOIB_CM_RX_ERROR, /* Ignored by stale task */
+ IPOIB_CM_RX_FLUSH /* Last WQE Reached event observed */
+};
+
struct ipoib_cm_rx {
struct ib_cm_id *id;
struct ib_qp *qp;
struct list_head list;
struct net_device *dev;
unsigned long jiffies;
+ enum ipoib_cm_state state;
};
struct ipoib_cm_tx {
@@ -165,10 +199,16 @@
struct ib_srq *srq;
struct ipoib_cm_rx_buf *srq_ring;
struct ib_cm_id *id;
- struct list_head passive_ids;
+ struct ib_qp *rx_drain_qp; /* generates WR described in 10.3.1 */
+ struct list_head passive_ids; /* state: LIVE */
+ struct list_head rx_error_list; /* state: ERROR */
+ struct list_head rx_flush_list; /* state: FLUSH, drain not started */
+ struct list_head rx_drain_list; /* state: FLUSH, drain started */
+ struct list_head rx_reap_list; /* state: FLUSH, drain done */
struct work_struct start_task;
struct work_struct reap_task;
struct work_struct skb_task;
+ struct work_struct rx_reap_task;
struct delayed_work stale_task;
struct sk_buff_head skb_queue;
struct list_head start_list;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index eec833b..ffec794 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -37,6 +37,7 @@
#include <net/dst.h>
#include <net/icmp.h>
#include <linux/icmpv6.h>
+#include <linux/delay.h>
#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
static int data_debug_level;
@@ -62,6 +63,16 @@
u32 remote_mtu;
};
+static struct ib_qp_attr ipoib_cm_err_attr = {
+ .qp_state = IB_QPS_ERR
+};
+
+#define IPOIB_CM_RX_DRAIN_WRID 0x7fffffff
+
+static struct ib_recv_wr ipoib_cm_rx_drain_wr = {
+ .wr_id = IPOIB_CM_RX_DRAIN_WRID
+};
+
static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
struct ib_cm_event *event);
@@ -150,11 +161,44 @@
return NULL;
}
+static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv* priv)
+{
+ struct ib_recv_wr *bad_wr;
+
+ /* rx_drain_qp send queue depth is 1, so
+ * make sure we have at most 1 outstanding WR. */
+ if (list_empty(&priv->cm.rx_flush_list) ||
+ !list_empty(&priv->cm.rx_drain_list))
+ return;
+
+ if (ib_post_recv(priv->cm.rx_drain_qp, &ipoib_cm_rx_drain_wr, &bad_wr))
+ ipoib_warn(priv, "failed to post rx_drain wr\n");
+
+ list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list);
+}
+
+static void ipoib_cm_rx_event_handler(struct ib_event *event, void *ctx)
+{
+ struct ipoib_cm_rx *p = ctx;
+ struct ipoib_dev_priv *priv = netdev_priv(p->dev);
+ unsigned long flags;
+
+ if (event->event != IB_EVENT_QP_LAST_WQE_REACHED)
+ return;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ list_move(&p->list, &priv->cm.rx_flush_list);
+ p->state = IPOIB_CM_RX_FLUSH;
+ ipoib_cm_start_rx_drain(priv);
+ spin_unlock_irqrestore(&priv->lock, flags);
+}
+
static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
struct ipoib_cm_rx *p)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct ib_qp_init_attr attr = {
+ .event_handler = ipoib_cm_rx_event_handler,
.send_cq = priv->cq, /* does not matter, we never send anything */
.recv_cq = priv->cq,
.srq = priv->cm.srq,
@@ -256,6 +300,7 @@
cm_id->context = p;
p->jiffies = jiffies;
+ p->state = IPOIB_CM_RX_LIVE;
spin_lock_irq(&priv->lock);
if (list_empty(&priv->cm.passive_ids))
queue_delayed_work(ipoib_workqueue,
@@ -277,7 +322,6 @@
{
struct ipoib_cm_rx *p;
struct ipoib_dev_priv *priv;
- int ret;
switch (event->event) {
case IB_CM_REQ_RECEIVED:
@@ -289,20 +333,9 @@
case IB_CM_REJ_RECEIVED:
p = cm_id->context;
priv = netdev_priv(p->dev);
- spin_lock_irq(&priv->lock);
- if (list_empty(&p->list))
- ret = 0; /* Connection is going away already. */
- else {
- list_del_init(&p->list);
- ret = -ECONNRESET;
- }
- spin_unlock_irq(&priv->lock);
- if (ret) {
- ib_destroy_qp(p->qp);
- kfree(p);
- return ret;
- }
- return 0;
+ if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
+ ipoib_warn(priv, "unable to move qp to error state\n");
+ /* Fall through */
default:
return 0;
}
@@ -354,8 +387,15 @@
wr_id, wc->status);
if (unlikely(wr_id >= ipoib_recvq_size)) {
- ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
- wr_id, ipoib_recvq_size);
+ if (wr_id == (IPOIB_CM_RX_DRAIN_WRID & ~IPOIB_CM_OP_SRQ)) {
+ spin_lock_irqsave(&priv->lock, flags);
+ list_splice_init(&priv->cm.rx_drain_list, &priv->cm.rx_reap_list);
+ ipoib_cm_start_rx_drain(priv);
+ queue_work(ipoib_workqueue, &priv->cm.rx_reap_task);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ } else
+ ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
+ wr_id, ipoib_recvq_size);
return;
}
@@ -374,9 +414,9 @@
if (p && time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
spin_lock_irqsave(&priv->lock, flags);
p->jiffies = jiffies;
- /* Move this entry to list head, but do
- * not re-add it if it has been removed. */
- if (!list_empty(&p->list))
+ /* Move this entry to list head, but do not re-add it
+ * if it has been moved out of list. */
+ if (p->state == IPOIB_CM_RX_LIVE)
list_move(&p->list, &priv->cm.passive_ids);
spin_unlock_irqrestore(&priv->lock, flags);
}
@@ -583,17 +623,43 @@
int ipoib_cm_dev_open(struct net_device *dev)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
+ struct ib_qp_init_attr qp_init_attr = {
+ .send_cq = priv->cq, /* does not matter, we never send anything */
+ .recv_cq = priv->cq,
+ .cap.max_send_wr = 1, /* FIXME: 0 Seems not to work */
+ .cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
+ .cap.max_recv_wr = 1,
+ .cap.max_recv_sge = 1, /* FIXME: 0 Seems not to work */
+ .sq_sig_type = IB_SIGNAL_ALL_WR,
+ .qp_type = IB_QPT_UC,
+ };
int ret;
if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
return 0;
+ priv->cm.rx_drain_qp = ib_create_qp(priv->pd, &qp_init_attr);
+ if (IS_ERR(priv->cm.rx_drain_qp)) {
+ printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
+ ret = PTR_ERR(priv->cm.rx_drain_qp);
+ return ret;
+ }
+
+ /*
+ * We put the QP in error state directly. This way, a "flush
+ * error" WC will be immediately generated for each WR we post.
+ */
+ ret = ib_modify_qp(priv->cm.rx_drain_qp, &ipoib_cm_err_attr, IB_QP_STATE);
+ if (ret) {
+ ipoib_warn(priv, "failed to modify drain QP to error: %d\n", ret);
+ goto err_qp;
+ }
+
priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
if (IS_ERR(priv->cm.id)) {
printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
ret = PTR_ERR(priv->cm.id);
- priv->cm.id = NULL;
- return ret;
+ goto err_cm;
}
ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
@@ -601,35 +667,79 @@
if (ret) {
printk(KERN_WARNING "%s: failed to listen on ID 0x%llx\n", priv->ca->name,
IPOIB_CM_IETF_ID | priv->qp->qp_num);
- ib_destroy_cm_id(priv->cm.id);
- priv->cm.id = NULL;
- return ret;
+ goto err_listen;
}
+
return 0;
+
+err_listen:
+ ib_destroy_cm_id(priv->cm.id);
+err_cm:
+ priv->cm.id = NULL;
+err_qp:
+ ib_destroy_qp(priv->cm.rx_drain_qp);
+ return ret;
}
void ipoib_cm_dev_stop(struct net_device *dev)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
- struct ipoib_cm_rx *p;
+ struct ipoib_cm_rx *p, *n;
+ unsigned long begin;
+ LIST_HEAD(list);
+ int ret;
if (!IPOIB_CM_SUPPORTED(dev->dev_addr) || !priv->cm.id)
return;
ib_destroy_cm_id(priv->cm.id);
priv->cm.id = NULL;
+
spin_lock_irq(&priv->lock);
while (!list_empty(&priv->cm.passive_ids)) {
p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
- list_del_init(&p->list);
+ list_move(&p->list, &priv->cm.rx_error_list);
+ p->state = IPOIB_CM_RX_ERROR;
spin_unlock_irq(&priv->lock);
+ ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
+ if (ret)
+ ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
+ spin_lock_irq(&priv->lock);
+ }
+
+ /* Wait for all RX to be drained */
+ begin = jiffies;
+
+ while (!list_empty(&priv->cm.rx_error_list) ||
+ !list_empty(&priv->cm.rx_flush_list) ||
+ !list_empty(&priv->cm.rx_drain_list)) {
+ if (!time_after(jiffies, begin + 5 * HZ)) {
+ ipoib_warn(priv, "RX drain timing out\n");
+
+ /*
+ * assume the HW is wedged and just free up everything.
+ */
+ list_splice_init(&priv->cm.rx_flush_list, &list);
+ list_splice_init(&priv->cm.rx_error_list, &list);
+ list_splice_init(&priv->cm.rx_drain_list, &list);
+ break;
+ }
+ spin_unlock_irq(&priv->lock);
+ msleep(1);
+ spin_lock_irq(&priv->lock);
+ }
+
+ list_splice_init(&priv->cm.rx_reap_list, &list);
+
+ spin_unlock_irq(&priv->lock);
+
+ list_for_each_entry_safe(p, n, &list, list) {
ib_destroy_cm_id(p->id);
ib_destroy_qp(p->qp);
kfree(p);
- spin_lock_irq(&priv->lock);
}
- spin_unlock_irq(&priv->lock);
+ ib_destroy_qp(priv->cm.rx_drain_qp);
cancel_delayed_work(&priv->cm.stale_task);
}
@@ -1079,24 +1189,44 @@
queue_work(ipoib_workqueue, &priv->cm.skb_task);
}
+static void ipoib_cm_rx_reap(struct work_struct *work)
+{
+ struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
+ cm.rx_reap_task);
+ struct ipoib_cm_rx *p, *n;
+ LIST_HEAD(list);
+
+ spin_lock_irq(&priv->lock);
+ list_splice_init(&priv->cm.rx_reap_list, &list);
+ spin_unlock_irq(&priv->lock);
+
+ list_for_each_entry_safe(p, n, &list, list) {
+ ib_destroy_cm_id(p->id);
+ ib_destroy_qp(p->qp);
+ kfree(p);
+ }
+}
+
static void ipoib_cm_stale_task(struct work_struct *work)
{
struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
cm.stale_task.work);
struct ipoib_cm_rx *p;
+ int ret;
spin_lock_irq(&priv->lock);
while (!list_empty(&priv->cm.passive_ids)) {
- /* List if sorted by LRU, start from tail,
+ /* List is sorted by LRU, start from tail,
* stop when we see a recently used entry */
p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
if (time_before_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
break;
- list_del_init(&p->list);
+ list_move(&p->list, &priv->cm.rx_error_list);
+ p->state = IPOIB_CM_RX_ERROR;
spin_unlock_irq(&priv->lock);
- ib_destroy_cm_id(p->id);
- ib_destroy_qp(p->qp);
- kfree(p);
+ ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
+ if (ret)
+ ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
spin_lock_irq(&priv->lock);
}
@@ -1164,9 +1294,14 @@
INIT_LIST_HEAD(&priv->cm.passive_ids);
INIT_LIST_HEAD(&priv->cm.reap_list);
INIT_LIST_HEAD(&priv->cm.start_list);
+ INIT_LIST_HEAD(&priv->cm.rx_error_list);
+ INIT_LIST_HEAD(&priv->cm.rx_flush_list);
+ INIT_LIST_HEAD(&priv->cm.rx_drain_list);
+ INIT_LIST_HEAD(&priv->cm.rx_reap_list);
INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
+ INIT_WORK(&priv->cm.rx_reap_task, ipoib_cm_rx_reap);
INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
skb_queue_head_init(&priv->cm.skb_queue);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_verbs.c b/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
index 7912526..982eb88 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
@@ -173,7 +173,7 @@
size = ipoib_sendq_size + ipoib_recvq_size + 1;
ret = ipoib_cm_dev_init(dev);
if (!ret)
- size += ipoib_recvq_size;
+ size += ipoib_recvq_size + 1 /* 1 extra for rx_drain_qp */;
priv->cq = ib_create_cq(priv->ca, ipoib_ib_completion, NULL, dev, size, 0);
if (IS_ERR(priv->cq)) {