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RDMA/cm: Allow ib_send_cm_dreq() to be done under lock 

The first thing ib_send_cm_dreq() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-12-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
alistair/sensors
Jason Gunthorpe 2020-03-10 11:25:41 +02:00
parent 00777a68ae
commit e029fdc068
1 changed files with 34 additions and 20 deletions
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54
drivers/infiniband/core/cm.c
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@ -80,8 +80,11 @@ const char *__attribute_const__ ibcm_reject_msg(int reason)
}
EXPORT_SYMBOL(ibcm_reject_msg);
struct cm_id_private;
static void cm_add_one(struct ib_device *device);
static void cm_remove_one(struct ib_device *device, void *client_data);
static int cm_send_dreq_locked(struct cm_id_private *cm_id_priv,
const void *private_data, u8 private_data_len);
static struct ib_client cm_client = {
.name = "cm",
@ -1084,10 +1087,12 @@ retest:
NULL, 0, NULL, 0);
break;
case IB_CM_ESTABLISHED:
spin_unlock_irq(&cm_id_priv->lock);
if (cm_id_priv->qp_type == IB_QPT_XRC_TGT)
if (cm_id_priv->qp_type == IB_QPT_XRC_TGT) {
spin_unlock_irq(&cm_id_priv->lock);
break;
ib_send_cm_dreq(cm_id, NULL, 0);
}
cm_send_dreq_locked(cm_id_priv, NULL, 0);
spin_unlock_irq(&cm_id_priv->lock);
goto retest;
case IB_CM_DREQ_SENT:
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
@ -2604,35 +2609,32 @@ static void cm_format_dreq(struct cm_dreq_msg *dreq_msg,
private_data_len);
}
int ib_send_cm_dreq(struct ib_cm_id *cm_id,
const void *private_data,
u8 private_data_len)
static int cm_send_dreq_locked(struct cm_id_private *cm_id_priv,
const void *private_data, u8 private_data_len)
{
struct cm_id_private *cm_id_priv;
struct ib_mad_send_buf *msg;
unsigned long flags;
int ret;
lockdep_assert_held(&cm_id_priv->lock);
if (private_data && private_data_len > IB_CM_DREQ_PRIVATE_DATA_SIZE)
return -EINVAL;
cm_id_priv = container_of(cm_id, struct cm_id_private, id);
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id->state != IB_CM_ESTABLISHED) {
if (cm_id_priv->id.state != IB_CM_ESTABLISHED) {
pr_debug("%s: local_id %d, cm_id->state: %d\n", __func__,
be32_to_cpu(cm_id->local_id), cm_id->state);
ret = -EINVAL;
goto out;
be32_to_cpu(cm_id_priv->id.local_id),
cm_id_priv->id.state);
return -EINVAL;
}
if (cm_id->lap_state == IB_CM_LAP_SENT ||
cm_id->lap_state == IB_CM_MRA_LAP_RCVD)
if (cm_id_priv->id.lap_state == IB_CM_LAP_SENT ||
cm_id_priv->id.lap_state == IB_CM_MRA_LAP_RCVD)
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
ret = cm_alloc_msg(cm_id_priv, &msg);
if (ret) {
cm_enter_timewait(cm_id_priv);
goto out;
return ret;
}
cm_format_dreq((struct cm_dreq_msg *) msg->mad, cm_id_priv,
@ -2643,14 +2645,26 @@ int ib_send_cm_dreq(struct ib_cm_id *cm_id,
ret = ib_post_send_mad(msg, NULL);
if (ret) {
cm_enter_timewait(cm_id_priv);
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
cm_free_msg(msg);
return ret;
}
cm_id->state = IB_CM_DREQ_SENT;
cm_id_priv->id.state = IB_CM_DREQ_SENT;
cm_id_priv->msg = msg;
out: spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return 0;
}
int ib_send_cm_dreq(struct ib_cm_id *cm_id, const void *private_data,
u8 private_data_len)
{
struct cm_id_private *cm_id_priv =
container_of(cm_id, struct cm_id_private, id);
unsigned long flags;
int ret;
spin_lock_irqsave(&cm_id_priv->lock, flags);
ret = cm_send_dreq_locked(cm_id_priv, private_data, private_data_len);
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
EXPORT_SYMBOL(ib_send_cm_dreq);