IB/sa: Track multicast join/leave requests

The IB SA tracks multicast join/leave requests on a per port basis and
does not do any reference counting: if two users of the same port join
the same group, and one leaves that group, then the SA will remove the
port from the group even though there is one user who wants to stay a
member left.  Therefore, in order to support multiple users of the
same multicast group from the same port, we need to perform reference
counting locally.

To do this, add an multicast submodule to ib_sa to perform reference
counting of multicast join/leave operations.  Modify ib_ipoib (the
only in-kernel user of multicast) to use the new interface.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 72 insertions, 123 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index fea737f520fd..b303ce6bc21e 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -60,14 +60,11 @@ static DEFINE_MUTEX(mcast_mutex);
 /* Used for all multicast joins (broadcast, IPv4 mcast and IPv6 mcast) */
 struct ipoib_mcast {
         struct ib_sa_mcmember_rec mcmember;
+        struct ib_sa_multicast   *mc;
         struct ipoib_ah          *ah;
 
         struct rb_node    rb_node;
         struct list_head  list;
-        struct completion done;
-
-        int                 query_id;
-        struct ib_sa_query *query;
 
         unsigned long created;
         unsigned long backoff;
@@ -299,18 +296,22 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
         return 0;
 }
 
-static void
+static int
 ipoib_mcast_sendonly_join_complete(int status,
-                                   struct ib_sa_mcmember_rec *mcmember,
-                                   void *mcast_ptr)
+                                   struct ib_sa_multicast *multicast)
 {
-        struct ipoib_mcast *mcast = mcast_ptr;
+        struct ipoib_mcast *mcast = multicast->context;
         struct net_device *dev = mcast->dev;
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
+        /* We trap for port events ourselves. */
+        if (status == -ENETRESET)
+                return 0;
+
         if (!status)
-                ipoib_mcast_join_finish(mcast, mcmember);
-        else {
+                status = ipoib_mcast_join_finish(mcast, &multicast->rec);
+
+        if (status) {
                 if (mcast->logcount++ < 20)
                         ipoib_dbg_mcast(netdev_priv(dev), "multicast join failed for "
                                         IPOIB_GID_FMT ", status %d\n",
@@ -325,11 +326,10 @@ ipoib_mcast_sendonly_join_complete(int status,
                 spin_unlock_irq(&priv->tx_lock);
 
                 /* Clear the busy flag so we try again */
-                clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
-                mcast->query = NULL;
+                status = test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY,
+                                            &mcast->flags);
         }
-
-        complete(&mcast->done);
+        return status;
 }
 
 static int ipoib_mcast_sendonly_join(struct ipoib_mcast *mcast)
@@ -359,35 +359,33 @@ static int ipoib_mcast_sendonly_join(struct ipoib_mcast *mcast)
         rec.port_gid = priv->local_gid;
         rec.pkey     = cpu_to_be16(priv->pkey);
 
-        init_completion(&mcast->done);
-
-        ret = ib_sa_mcmember_rec_set(&ipoib_sa_client, priv->ca, priv->port, &rec,
-                                     IB_SA_MCMEMBER_REC_MGID            |
-                                     IB_SA_MCMEMBER_REC_PORT_GID        |
-                                     IB_SA_MCMEMBER_REC_PKEY            |
-                                     IB_SA_MCMEMBER_REC_JOIN_STATE,
-                                     1000, GFP_ATOMIC,
-                                     ipoib_mcast_sendonly_join_complete,
-                                     mcast, &mcast->query);
-        if (ret < 0) {
-                ipoib_warn(priv, "ib_sa_mcmember_rec_set failed (ret = %d)\n",
+        mcast->mc = ib_sa_join_multicast(&ipoib_sa_client, priv->ca,
+                                         priv->port, &rec,
+                                         IB_SA_MCMEMBER_REC_MGID        |
+                                         IB_SA_MCMEMBER_REC_PORT_GID    |
+                                         IB_SA_MCMEMBER_REC_PKEY        |
+                                         IB_SA_MCMEMBER_REC_JOIN_STATE,
+                                         GFP_ATOMIC,
+                                         ipoib_mcast_sendonly_join_complete,
+                                         mcast);
+        if (IS_ERR(mcast->mc)) {
+                ret = PTR_ERR(mcast->mc);
+                clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
+                ipoib_warn(priv, "ib_sa_join_multicast failed (ret = %d)\n",
                            ret);
         } else {
                 ipoib_dbg_mcast(priv, "no multicast record for " IPOIB_GID_FMT
                                 ", starting join\n",
                                 IPOIB_GID_ARG(mcast->mcmember.mgid));
-
-                mcast->query_id = ret;
         }
 
         return ret;
 }
 
-static void ipoib_mcast_join_complete(int status,
-                                      struct ib_sa_mcmember_rec *mcmember,
-                                      void *mcast_ptr)
+static int ipoib_mcast_join_complete(int status,
+                                     struct ib_sa_multicast *multicast)
 {
-        struct ipoib_mcast *mcast = mcast_ptr;
+        struct ipoib_mcast *mcast = multicast->context;
         struct net_device *dev = mcast->dev;
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
@@ -395,24 +393,25 @@ static void ipoib_mcast_join_complete(int status,
                         " (status %d)\n",
                         IPOIB_GID_ARG(mcast->mcmember.mgid), status);
 
-        if (!status && !ipoib_mcast_join_finish(mcast, mcmember)) {
+        /* We trap for port events ourselves. */
+        if (status == -ENETRESET)
+                return 0;
+
+        if (!status)
+                status = ipoib_mcast_join_finish(mcast, &multicast->rec);
+
+        if (!status) {
                 mcast->backoff = 1;
                 mutex_lock(&mcast_mutex);
                 if (test_bit(IPOIB_MCAST_RUN, &priv->flags))
                         queue_delayed_work(ipoib_workqueue,
                                            &priv->mcast_task, 0);
                 mutex_unlock(&mcast_mutex);
-                complete(&mcast->done);
-                return;
-        }
-
-        if (status == -EINTR) {
-                complete(&mcast->done);
-                return;
+                return 0;
         }
 
-        if (status && mcast->logcount++ < 20) {
-                if (status == -ETIMEDOUT || status == -EINTR) {
+        if (mcast->logcount++ < 20) {
+                if (status == -ETIMEDOUT) {
                         ipoib_dbg_mcast(priv, "multicast join failed for " IPOIB_GID_FMT
                                         ", status %d\n",
                                         IPOIB_GID_ARG(mcast->mcmember.mgid),
@@ -429,24 +428,18 @@ static void ipoib_mcast_join_complete(int status,
         if (mcast->backoff > IPOIB_MAX_BACKOFF_SECONDS)
                 mcast->backoff = IPOIB_MAX_BACKOFF_SECONDS;
 
-        mutex_lock(&mcast_mutex);
+        /* Clear the busy flag so we try again */
+        status = test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
 
+        mutex_lock(&mcast_mutex);
         spin_lock_irq(&priv->lock);
-        mcast->query = NULL;
-
-        if (test_bit(IPOIB_MCAST_RUN, &priv->flags)) {
-                if (status == -ETIMEDOUT)
-                        queue_delayed_work(ipoib_workqueue, &priv->mcast_task,
-                                           0);
-                else
-                        queue_delayed_work(ipoib_workqueue, &priv->mcast_task,
-                                           mcast->backoff * HZ);
-        } else
-                complete(&mcast->done);
+        if (test_bit(IPOIB_MCAST_RUN, &priv->flags))
+                queue_delayed_work(ipoib_workqueue, &priv->mcast_task,
+                                   mcast->backoff * HZ);
         spin_unlock_irq(&priv->lock);
         mutex_unlock(&mcast_mutex);
 
-        return;
+        return status;
 }
 
 static void ipoib_mcast_join(struct net_device *dev, struct ipoib_mcast *mcast,
@@ -495,15 +488,14 @@ static void ipoib_mcast_join(struct net_device *dev, struct ipoib_mcast *mcast,
                 rec.hop_limit     = priv->broadcast->mcmember.hop_limit;
         }
 
-        init_completion(&mcast->done);
-
-        ret = ib_sa_mcmember_rec_set(&ipoib_sa_client, priv->ca, priv->port,
-                                     &rec, comp_mask, mcast->backoff * 1000,
-                                     GFP_ATOMIC, ipoib_mcast_join_complete,
-                                     mcast, &mcast->query);
-
-        if (ret < 0) {
-                ipoib_warn(priv, "ib_sa_mcmember_rec_set failed, status %d\n", ret);
+        set_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
+        mcast->mc = ib_sa_join_multicast(&ipoib_sa_client, priv->ca, priv->port,
+                                         &rec, comp_mask, GFP_KERNEL,
+                                         ipoib_mcast_join_complete, mcast);
+        if (IS_ERR(mcast->mc)) {
+                clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
+                ret = PTR_ERR(mcast->mc);
+                ipoib_warn(priv, "ib_sa_join_multicast failed, status %d\n", ret);
 
                 mcast->backoff *= 2;
                 if (mcast->backoff > IPOIB_MAX_BACKOFF_SECONDS)
@@ -515,8 +507,7 @@ static void ipoib_mcast_join(struct net_device *dev, struct ipoib_mcast *mcast,
                                            &priv->mcast_task,
                                            mcast->backoff * HZ);
                 mutex_unlock(&mcast_mutex);
-        } else
-                mcast->query_id = ret;
+        }
 }
 
 void ipoib_mcast_join_task(struct work_struct *work)
@@ -541,7 +532,7 @@ void ipoib_mcast_join_task(struct work_struct *work)
                         priv->local_rate = attr.active_speed *
                                 ib_width_enum_to_int(attr.active_width);
                 } else
-                ipoib_warn(priv, "ib_query_port failed\n");
+                        ipoib_warn(priv, "ib_query_port failed\n");
         }
 
         if (!priv->broadcast) {
@@ -568,7 +559,8 @@ void ipoib_mcast_join_task(struct work_struct *work)
         }
 
         if (!test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) {
-                ipoib_mcast_join(dev, priv->broadcast, 0);
+                if (!test_bit(IPOIB_MCAST_FLAG_BUSY, &priv->broadcast->flags))
+                        ipoib_mcast_join(dev, priv->broadcast, 0);
                 return;
         }
 
@@ -625,26 +617,9 @@ int ipoib_mcast_start_thread(struct net_device *dev)
         return 0;
 }
 
-static void wait_for_mcast_join(struct ipoib_dev_priv *priv,
-                                struct ipoib_mcast *mcast)
-{
-        spin_lock_irq(&priv->lock);
-        if (mcast && mcast->query) {
-                ib_sa_cancel_query(mcast->query_id, mcast->query);
-                mcast->query = NULL;
-                spin_unlock_irq(&priv->lock);
-                ipoib_dbg_mcast(priv, "waiting for MGID " IPOIB_GID_FMT "\n",
-                                IPOIB_GID_ARG(mcast->mcmember.mgid));
-                wait_for_completion(&mcast->done);
-        }
-        else
-                spin_unlock_irq(&priv->lock);
-}
-
 int ipoib_mcast_stop_thread(struct net_device *dev, int flush)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
-        struct ipoib_mcast *mcast;
 
         ipoib_dbg_mcast(priv, "stopping multicast thread\n");
 
@@ -660,52 +635,27 @@ int ipoib_mcast_stop_thread(struct net_device *dev, int flush)
         if (flush)
                 flush_workqueue(ipoib_workqueue);
 
-        wait_for_mcast_join(priv, priv->broadcast);
-
-        list_for_each_entry(mcast, &priv->multicast_list, list)
-                wait_for_mcast_join(priv, mcast);
-
         return 0;
 }
 
 static int ipoib_mcast_leave(struct net_device *dev, struct ipoib_mcast *mcast)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
-        struct ib_sa_mcmember_rec rec = {
-                .join_state = 1
-        };
         int ret = 0;
 
-        if (!test_and_clear_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags))
-                return 0;
-
-        ipoib_dbg_mcast(priv, "leaving MGID " IPOIB_GID_FMT "\n",
-                        IPOIB_GID_ARG(mcast->mcmember.mgid));
-
-        rec.mgid     = mcast->mcmember.mgid;
-        rec.port_gid = priv->local_gid;
-        rec.pkey     = cpu_to_be16(priv->pkey);
+        if (test_and_clear_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags)) {
+                ipoib_dbg_mcast(priv, "leaving MGID " IPOIB_GID_FMT "\n",
+                                IPOIB_GID_ARG(mcast->mcmember.mgid));
 
-        /* Remove ourselves from the multicast group */
-        ret = ipoib_mcast_detach(dev, be16_to_cpu(mcast->mcmember.mlid),
-                                 &mcast->mcmember.mgid);
-        if (ret)
-                ipoib_warn(priv, "ipoib_mcast_detach failed (result = %d)\n", ret);
+                /* Remove ourselves from the multicast group */
+                ret = ipoib_mcast_detach(dev, be16_to_cpu(mcast->mcmember.mlid),
+                                         &mcast->mcmember.mgid);
+                if (ret)
+                        ipoib_warn(priv, "ipoib_mcast_detach failed (result = %d)\n", ret);
+        }
 
-        /*
-         * Just make one shot at leaving and don't wait for a reply;
-         * if we fail, too bad.
-         */
-        ret = ib_sa_mcmember_rec_delete(&ipoib_sa_client, priv->ca, priv->port, &rec,
-                                        IB_SA_MCMEMBER_REC_MGID         |
-                                        IB_SA_MCMEMBER_REC_PORT_GID     |
-                                        IB_SA_MCMEMBER_REC_PKEY         |
-                                        IB_SA_MCMEMBER_REC_JOIN_STATE,
-                                        0, GFP_ATOMIC, NULL,
-                                        mcast, &mcast->query);
-        if (ret < 0)
-                ipoib_warn(priv, "ib_sa_mcmember_rec_delete failed "
-                           "for leave (result = %d)\n", ret);
+        if (test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags))
+                ib_sa_free_multicast(mcast->mc);
 
         return 0;
 }
@@ -758,7 +708,7 @@ void ipoib_mcast_send(struct net_device *dev, void *mgid, struct sk_buff *skb)
                         dev_kfree_skb_any(skb);
                 }
 
-                if (mcast->query)
+                if (test_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags))
                         ipoib_dbg_mcast(priv, "no address vector, "
                                         "but multicast join already started\n");
                 else if (test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags))
@@ -916,7 +866,6 @@ void ipoib_mcast_restart_task(struct work_struct *work)
 
         /* We have to cancel outside of the spinlock */
         list_for_each_entry_safe(mcast, tmcast, &remove_list, list) {
-                wait_for_mcast_join(priv, mcast);
                 ipoib_mcast_leave(mcast->dev, mcast);
                 ipoib_mcast_free(mcast);
         }