[PATCH rdma-next v3 7/8] IB/cm: Improve the calling of cm_init_av_for_lap and cm_init_av_by_path

Leon Romanovsky
2021-05-11T08:32:21Z

From: Mark Zhang <markzhang@nvidia.com>

The cm_init_av_for_lap() and cm_init_av_by_path() function calls have
the following issues:
1. Both of them might sleep and should not be called under spinlock.
2. The access of cm_id_priv->av should be under cm_id_priv->lock, which
means it cann't be initialized directly.

This patch splits the calling of 2 functions into two parts: first one
initializes an AV outside of the spinlock, the second one copies AV to
cm_id_priv->av under spinlock.

Fixes: e1444b5a163e ("IB/cm: Fix automatic path migration support")
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/infiniband/core/cm.c | 105 +++++++++++++++++++----------------
1 file changed, 58 insertions(+), 47 deletions(-)

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 2d62c90f9790..2e4658795e8e 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -440,30 +440,12 @@ static void cm_set_private_data(struct cm_id_private *cm_id_priv,
cm_id_priv->private_data_len = private_data_len;
}

-static int cm_init_av_for_lap(struct cm_port *port, struct ib_wc *wc,
- struct ib_grh *grh, struct cm_av *av)
+static void cm_init_av_for_lap(struct cm_port *port, struct ib_wc *wc,
+ struct rdma_ah_attr *ah_attr, struct cm_av *av)
{
- struct rdma_ah_attr new_ah_attr;
- int ret;
-
av->port = port;
av->pkey_index = wc->pkey_index;
-
- /*
- * av->ah_attr might be initialized based on past wc during incoming
- * connect request or while sending out connect request. So initialize
- * a new ah_attr on stack. If initialization fails, old ah_attr is
- * used for sending any responses. If initialization is successful,
- * than new ah_attr is used by overwriting old one.
- */
- ret = ib_init_ah_attr_from_wc(port->cm_dev->ib_device,
- port->port_num, wc,
- grh, &new_ah_attr);
- if (ret)
- return ret;
-
- rdma_move_ah_attr(&av->ah_attr, &new_ah_attr);
- return 0;
+ rdma_move_ah_attr(&av->ah_attr, ah_attr);
}

static int cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
@@ -557,6 +539,20 @@ static int cm_init_av_by_path(struct sa_path_rec *path,
return 0;
}

+/* Move av created by cm_init_av_by_path(), so av.dgid is not moved */
+static void cm_move_av_from_path(struct cm_av *dest, struct cm_av *src)
+{
+ dest->port = src->port;
+ dest->pkey_index = src->pkey_index;
+ rdma_move_ah_attr(&dest->ah_attr, &src->ah_attr);
+ dest->timeout = src->timeout;
+}
+
+static void cm_destroy_av(struct cm_av *av)
+{
+ rdma_destroy_ah_attr(&av->ah_attr);
+}
+
static u32 cm_local_id(__be32 local_id)
{
return (__force u32) (local_id ^ cm.random_id_operand);
@@ -1146,8 +1142,8 @@ static void cm_destroy_id(struct ib_cm_id *cm_id, int err)
while ((work = cm_dequeue_work(cm_id_priv)) != NULL)
cm_free_work(work);

- rdma_destroy_ah_attr(&cm_id_priv->av.ah_attr);
- rdma_destroy_ah_attr(&cm_id_priv->alt_av.ah_attr);
+ cm_destroy_av(&cm_id_priv->av);
+ cm_destroy_av(&cm_id_priv->alt_av);
kfree(cm_id_priv->private_data);
kfree_rcu(cm_id_priv, rcu);
}
@@ -1471,6 +1467,7 @@ static int cm_validate_req_param(struct ib_cm_req_param *param)
int ib_send_cm_req(struct ib_cm_id *cm_id,
struct ib_cm_req_param *param)
{
+ struct cm_av av = {}, alt_av = {};
struct cm_id_private *cm_id_priv;
struct ib_mad_send_buf *msg;
struct cm_req_msg *req_msg;
@@ -1486,8 +1483,7 @@ int ib_send_cm_req(struct ib_cm_id *cm_id,
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id->state != IB_CM_IDLE || WARN_ON(cm_id_priv->timewait_info)) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);

@@ -1496,18 +1492,20 @@ int ib_send_cm_req(struct ib_cm_id *cm_id,
if (IS_ERR(cm_id_priv->timewait_info)) {
ret = PTR_ERR(cm_id_priv->timewait_info);
cm_id_priv->timewait_info = NULL;
- goto out;
+ return ret;
}

ret = cm_init_av_by_path(param->primary_path,
- param->ppath_sgid_attr, &cm_id_priv->av);
+ param->ppath_sgid_attr, &av);
if (ret)
- goto out;
+ return ret;
if (param->alternate_path) {
ret = cm_init_av_by_path(param->alternate_path, NULL,
- &cm_id_priv->alt_av);
- if (ret)
- goto out;
+ &alt_av);
+ if (ret) {
+ cm_destroy_av(&av);
+ return ret;
+ }
}
cm_id->service_id = param->service_id;
cm_id->service_mask = ~cpu_to_be64(0);
@@ -1524,6 +1522,11 @@ int ib_send_cm_req(struct ib_cm_id *cm_id,
cm_id_priv->qp_type = param->qp_type;

spin_lock_irqsave(&cm_id_priv->lock, flags);
+
+ cm_move_av_from_path(&cm_id_priv->av, &av);
+ if (param->alternate_path)
+ cm_move_av_from_path(&cm_id_priv->alt_av, &alt_av);
+
msg = cm_alloc_priv_msg(cm_id_priv);
if (IS_ERR(msg)) {
ret = PTR_ERR(msg);
@@ -1551,7 +1554,6 @@ int ib_send_cm_req(struct ib_cm_id *cm_id,
cm_free_priv_msg(msg);
out_unlock:
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
-out:
return ret;
}
EXPORT_SYMBOL(ib_send_cm_req);
@@ -3264,6 +3266,8 @@ static int cm_lap_handler(struct cm_work *work)
struct cm_lap_msg *lap_msg;
struct ib_cm_lap_event_param *param;
struct ib_mad_send_buf *msg = NULL;
+ struct rdma_ah_attr ah_attr;
+ struct cm_av alt_av = {};
int ret;

/* Currently Alternate path messages are not supported for
@@ -3292,7 +3296,25 @@ static int cm_lap_handler(struct cm_work *work)
work->cm_event.private_data =
IBA_GET_MEM_PTR(CM_LAP_PRIVATE_DATA, lap_msg);

+ ret = ib_init_ah_attr_from_wc(work->port->cm_dev->ib_device,
+ work->port->port_num,
+ work->mad_recv_wc->wc,
+ work->mad_recv_wc->recv_buf.grh,
+ &ah_attr);
+ if (ret)
+ goto deref;
+
+ ret = cm_init_av_by_path(param->alternate_path, NULL, &alt_av);
+ if (ret) {
+ rdma_destroy_ah_attr(&ah_attr);
+ return -EINVAL;
+ }
+
spin_lock_irq(&cm_id_priv->lock);
+ cm_init_av_for_lap(work->port, work->mad_recv_wc->wc,
+ &ah_attr, &cm_id_priv->av);
+ cm_move_av_from_path(&cm_id_priv->alt_av, &alt_av);
+
if (cm_id_priv->id.state != IB_CM_ESTABLISHED)
goto unlock;

@@ -3326,17 +3348,6 @@ static int cm_lap_handler(struct cm_work *work)
goto unlock;
}

- ret = cm_init_av_for_lap(work->port, work->mad_recv_wc->wc,
- work->mad_recv_wc->recv_buf.grh,
- &cm_id_priv->av);
- if (ret)
- goto unlock;
-
- ret = cm_init_av_by_path(param->alternate_path, NULL,
- &cm_id_priv->alt_av);
- if (ret)
- goto unlock;
-
cm_id_priv->id.lap_state = IB_CM_LAP_RCVD;
cm_id_priv->tid = lap_msg->hdr.tid;
cm_queue_work_unlock(cm_id_priv, work);
@@ -3443,6 +3454,7 @@ int ib_send_cm_sidr_req(struct ib_cm_id *cm_id,
{
struct cm_id_private *cm_id_priv;
struct ib_mad_send_buf *msg;
+ struct cm_av av = {};
unsigned long flags;
int ret;

@@ -3451,17 +3463,16 @@ int ib_send_cm_sidr_req(struct ib_cm_id *cm_id,
return -EINVAL;

cm_id_priv = container_of(cm_id, struct cm_id_private, id);
- ret = cm_init_av_by_path(param->path, param->sgid_attr,
- &cm_id_priv->av);
+ ret = cm_init_av_by_path(param->path, param->sgid_attr, &av);
if (ret)
return ret;

+ spin_lock_irqsave(&cm_id_priv->lock, flags);
+ cm_move_av_from_path(&cm_id_priv->av, &av);
cm_id->service_id = param->service_id;
cm_id->service_mask = ~cpu_to_be64(0);
cm_id_priv->timeout_ms = param->timeout_ms;
cm_id_priv->max_cm_retries = param->max_cm_retries;
-
- spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id->state != IB_CM_IDLE) {
ret = -EINVAL;
goto out_unlock;
--
2.31.1