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

The first thing ib_send_cm_drep() 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/20200310092545.251365-13-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 11:25:42 +02:00
parent e029fdc068
commit 87cabf3e09
1 changed files with 33 additions and 22 deletions
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55
drivers/infiniband/core/cm.c
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@ -85,6 +85,8 @@ 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 int cm_send_drep_locked(struct cm_id_private *cm_id_priv,
void *private_data, u8 private_data_len);
static struct ib_client cm_client = {
.name = "cm",
@ -1100,8 +1102,8 @@ retest:
spin_unlock_irq(&cm_id_priv->lock);
break;
case IB_CM_DREQ_RCVD:
cm_send_drep_locked(cm_id_priv, NULL, 0);
spin_unlock_irq(&cm_id_priv->lock);
ib_send_cm_drep(cm_id, NULL, 0);
break;
default:
spin_unlock_irq(&cm_id_priv->lock);
@ -2685,51 +2687,60 @@ static void cm_format_drep(struct cm_drep_msg *drep_msg,
private_data_len);
}
int ib_send_cm_drep(struct ib_cm_id *cm_id,
const void *private_data,
u8 private_data_len)
static int cm_send_drep_locked(struct cm_id_private *cm_id_priv,
void *private_data, u8 private_data_len)
{
struct cm_id_private *cm_id_priv;
struct ib_mad_send_buf *msg;
unsigned long flags;
void *data;
int ret;
lockdep_assert_held(&cm_id_priv->lock);
if (private_data && private_data_len > IB_CM_DREP_PRIVATE_DATA_SIZE)
return -EINVAL;
data = cm_copy_private_data(private_data, private_data_len);
if (IS_ERR(data))
return PTR_ERR(data);
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_DREQ_RCVD) {
pr_debug("%s: local_id %d, cm_idcm_id->state(%d) != IB_CM_DREQ_RCVD\n",
__func__, be32_to_cpu(cm_id->local_id), cm_id->state);
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
kfree(data);
if (cm_id_priv->id.state != IB_CM_DREQ_RCVD) {
pr_debug(
"%s: local_id %d, cm_idcm_id->state(%d) != IB_CM_DREQ_RCVD\n",
__func__, be32_to_cpu(cm_id_priv->id.local_id),
cm_id_priv->id.state);
kfree(private_data);
return -EINVAL;
}
cm_set_private_data(cm_id_priv, data, private_data_len);
cm_set_private_data(cm_id_priv, private_data, private_data_len);
cm_enter_timewait(cm_id_priv);
ret = cm_alloc_msg(cm_id_priv, &msg);
if (ret)
goto out;
return ret;
cm_format_drep((struct cm_drep_msg *) msg->mad, cm_id_priv,
private_data, private_data_len);
ret = ib_post_send_mad(msg, NULL);
if (ret) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
cm_free_msg(msg);
return ret;
}
return 0;
}
out: spin_unlock_irqrestore(&cm_id_priv->lock, flags);
int ib_send_cm_drep(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;
void *data;
int ret;
data = cm_copy_private_data(private_data, private_data_len);
if (IS_ERR(data))
return PTR_ERR(data);
spin_lock_irqsave(&cm_id_priv->lock, flags);
ret = cm_send_drep_locked(cm_id_priv, data, private_data_len);
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
EXPORT_SYMBOL(ib_send_cm_drep);