forked from Minki/linux
RDMA/cma: Simplify locking needed for serialization of callbacks
The RDMA CM has some logic in place to make sure that callbacks on a given CM ID are delivered to the consumer in a serialized manner. Specifically it has code to protect against a device removal racing with a running callback function. This patch simplifies this logic by using a mutex per ID instead of a wait queue and atomic variable. This means that cma_disable_remove() now is more properly named to cma_disable_callback(), and cma_enable_remove() can now be removed because it just would become a trivial wrapper around mutex_unlock(). Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Or Gerlitz
Roland Dreier
parent
64c5e613b9
commit
de910bd921
@ -130,8 +130,7 @@ struct rdma_id_private {
|
||||
|
||||
struct completion comp;
|
||||
atomic_t refcount;
|
||||
wait_queue_head_t wait_remove;
|
||||
atomic_t dev_remove;
|
||||
struct mutex handler_mutex;
|
||||
|
||||
int backlog;
|
||||
int timeout_ms;
|
||||
@ -355,26 +354,15 @@ static void cma_deref_id(struct rdma_id_private *id_priv)
|
||||
complete(&id_priv->comp);
|
||||
}
|
||||
|
||||
static int cma_disable_remove(struct rdma_id_private *id_priv,
|
||||
static int cma_disable_callback(struct rdma_id_private *id_priv,
|
||||
enum cma_state state)
|
||||
{
|
||||
unsigned long flags;
|
||||
int ret;
|
||||
|
||||
spin_lock_irqsave(&id_priv->lock, flags);
|
||||
if (id_priv->state == state) {
|
||||
atomic_inc(&id_priv->dev_remove);
|
||||
ret = 0;
|
||||
} else
|
||||
ret = -EINVAL;
|
||||
spin_unlock_irqrestore(&id_priv->lock, flags);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void cma_enable_remove(struct rdma_id_private *id_priv)
|
||||
{
|
||||
if (atomic_dec_and_test(&id_priv->dev_remove))
|
||||
wake_up(&id_priv->wait_remove);
|
||||
mutex_lock(&id_priv->handler_mutex);
|
||||
if (id_priv->state != state) {
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
return -EINVAL;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int cma_has_cm_dev(struct rdma_id_private *id_priv)
|
||||
@ -399,8 +387,7 @@ struct rdma_cm_id *rdma_create_id(rdma_cm_event_handler event_handler,
|
||||
mutex_init(&id_priv->qp_mutex);
|
||||
init_completion(&id_priv->comp);
|
||||
atomic_set(&id_priv->refcount, 1);
|
||||
init_waitqueue_head(&id_priv->wait_remove);
|
||||
atomic_set(&id_priv->dev_remove, 0);
|
||||
mutex_init(&id_priv->handler_mutex);
|
||||
INIT_LIST_HEAD(&id_priv->listen_list);
|
||||
INIT_LIST_HEAD(&id_priv->mc_list);
|
||||
get_random_bytes(&id_priv->seq_num, sizeof id_priv->seq_num);
|
||||
@ -927,7 +914,7 @@ static int cma_ib_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
|
||||
struct rdma_cm_event event;
|
||||
int ret = 0;
|
||||
|
||||
if (cma_disable_remove(id_priv, CMA_CONNECT))
|
||||
if (cma_disable_callback(id_priv, CMA_CONNECT))
|
||||
return 0;
|
||||
|
||||
memset(&event, 0, sizeof event);
|
||||
@ -984,12 +971,12 @@ static int cma_ib_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
|
||||
/* Destroy the CM ID by returning a non-zero value. */
|
||||
id_priv->cm_id.ib = NULL;
|
||||
cma_exch(id_priv, CMA_DESTROYING);
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
rdma_destroy_id(&id_priv->id);
|
||||
return ret;
|
||||
}
|
||||
out:
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -1101,7 +1088,7 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
|
||||
int offset, ret;
|
||||
|
||||
listen_id = cm_id->context;
|
||||
if (cma_disable_remove(listen_id, CMA_LISTEN))
|
||||
if (cma_disable_callback(listen_id, CMA_LISTEN))
|
||||
return -ECONNABORTED;
|
||||
|
||||
memset(&event, 0, sizeof event);
|
||||
@ -1122,7 +1109,7 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
|
||||
goto out;
|
||||
}
|
||||
|
||||
atomic_inc(&conn_id->dev_remove);
|
||||
mutex_lock_nested(&conn_id->handler_mutex, SINGLE_DEPTH_NESTING);
|
||||
mutex_lock(&lock);
|
||||
ret = cma_acquire_dev(conn_id);
|
||||
mutex_unlock(&lock);
|
||||
@ -1144,7 +1131,7 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
|
||||
!cma_is_ud_ps(conn_id->id.ps))
|
||||
ib_send_cm_mra(cm_id, CMA_CM_MRA_SETTING, NULL, 0);
|
||||
mutex_unlock(&lock);
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
goto out;
|
||||
}
|
||||
|
||||
@ -1153,11 +1140,11 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
|
||||
|
||||
release_conn_id:
|
||||
cma_exch(conn_id, CMA_DESTROYING);
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
rdma_destroy_id(&conn_id->id);
|
||||
|
||||
out:
|
||||
cma_enable_remove(listen_id);
|
||||
mutex_unlock(&listen_id->handler_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -1223,7 +1210,7 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event)
|
||||
struct sockaddr_in *sin;
|
||||
int ret = 0;
|
||||
|
||||
if (cma_disable_remove(id_priv, CMA_CONNECT))
|
||||
if (cma_disable_callback(id_priv, CMA_CONNECT))
|
||||
return 0;
|
||||
|
||||
memset(&event, 0, sizeof event);
|
||||
@ -1267,12 +1254,12 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event)
|
||||
/* Destroy the CM ID by returning a non-zero value. */
|
||||
id_priv->cm_id.iw = NULL;
|
||||
cma_exch(id_priv, CMA_DESTROYING);
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
rdma_destroy_id(&id_priv->id);
|
||||
return ret;
|
||||
}
|
||||
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -1288,7 +1275,7 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id,
|
||||
struct ib_device_attr attr;
|
||||
|
||||
listen_id = cm_id->context;
|
||||
if (cma_disable_remove(listen_id, CMA_LISTEN))
|
||||
if (cma_disable_callback(listen_id, CMA_LISTEN))
|
||||
return -ECONNABORTED;
|
||||
|
||||
/* Create a new RDMA id for the new IW CM ID */
|
||||
@ -1300,19 +1287,19 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id,
|
||||
goto out;
|
||||
}
|
||||
conn_id = container_of(new_cm_id, struct rdma_id_private, id);
|
||||
atomic_inc(&conn_id->dev_remove);
|
||||
mutex_lock_nested(&conn_id->handler_mutex, SINGLE_DEPTH_NESTING);
|
||||
conn_id->state = CMA_CONNECT;
|
||||
|
||||
dev = ip_dev_find(&init_net, iw_event->local_addr.sin_addr.s_addr);
|
||||
if (!dev) {
|
||||
ret = -EADDRNOTAVAIL;
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
rdma_destroy_id(new_cm_id);
|
||||
goto out;
|
||||
}
|
||||
ret = rdma_copy_addr(&conn_id->id.route.addr.dev_addr, dev, NULL);
|
||||
if (ret) {
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
rdma_destroy_id(new_cm_id);
|
||||
goto out;
|
||||
}
|
||||
@ -1321,7 +1308,7 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id,
|
||||
ret = cma_acquire_dev(conn_id);
|
||||
mutex_unlock(&lock);
|
||||
if (ret) {
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
rdma_destroy_id(new_cm_id);
|
||||
goto out;
|
||||
}
|
||||
@ -1337,7 +1324,7 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id,
|
||||
|
||||
ret = ib_query_device(conn_id->id.device, &attr);
|
||||
if (ret) {
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
rdma_destroy_id(new_cm_id);
|
||||
goto out;
|
||||
}
|
||||
@ -1353,14 +1340,17 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id,
|
||||
/* User wants to destroy the CM ID */
|
||||
conn_id->cm_id.iw = NULL;
|
||||
cma_exch(conn_id, CMA_DESTROYING);
|
||||
cma_enable_remove(conn_id);
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
rdma_destroy_id(&conn_id->id);
|
||||
goto out;
|
||||
}
|
||||
|
||||
mutex_unlock(&conn_id->handler_mutex);
|
||||
|
||||
out:
|
||||
if (dev)
|
||||
dev_put(dev);
|
||||
cma_enable_remove(listen_id);
|
||||
mutex_unlock(&listen_id->handler_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -1592,7 +1582,7 @@ static void cma_work_handler(struct work_struct *_work)
|
||||
struct rdma_id_private *id_priv = work->id;
|
||||
int destroy = 0;
|
||||
|
||||
atomic_inc(&id_priv->dev_remove);
|
||||
mutex_lock(&id_priv->handler_mutex);
|
||||
if (!cma_comp_exch(id_priv, work->old_state, work->new_state))
|
||||
goto out;
|
||||
|
||||
@ -1601,7 +1591,7 @@ static void cma_work_handler(struct work_struct *_work)
|
||||
destroy = 1;
|
||||
}
|
||||
out:
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
cma_deref_id(id_priv);
|
||||
if (destroy)
|
||||
rdma_destroy_id(&id_priv->id);
|
||||
@ -1764,7 +1754,7 @@ static void addr_handler(int status, struct sockaddr *src_addr,
|
||||
struct rdma_cm_event event;
|
||||
|
||||
memset(&event, 0, sizeof event);
|
||||
atomic_inc(&id_priv->dev_remove);
|
||||
mutex_lock(&id_priv->handler_mutex);
|
||||
|
||||
/*
|
||||
* Grab mutex to block rdma_destroy_id() from removing the device while
|
||||
@ -1793,13 +1783,13 @@ static void addr_handler(int status, struct sockaddr *src_addr,
|
||||
|
||||
if (id_priv->id.event_handler(&id_priv->id, &event)) {
|
||||
cma_exch(id_priv, CMA_DESTROYING);
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
cma_deref_id(id_priv);
|
||||
rdma_destroy_id(&id_priv->id);
|
||||
return;
|
||||
}
|
||||
out:
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
cma_deref_id(id_priv);
|
||||
}
|
||||
|
||||
@ -2126,7 +2116,7 @@ static int cma_sidr_rep_handler(struct ib_cm_id *cm_id,
|
||||
struct ib_cm_sidr_rep_event_param *rep = &ib_event->param.sidr_rep_rcvd;
|
||||
int ret = 0;
|
||||
|
||||
if (cma_disable_remove(id_priv, CMA_CONNECT))
|
||||
if (cma_disable_callback(id_priv, CMA_CONNECT))
|
||||
return 0;
|
||||
|
||||
memset(&event, 0, sizeof event);
|
||||
@ -2167,12 +2157,12 @@ static int cma_sidr_rep_handler(struct ib_cm_id *cm_id,
|
||||
/* Destroy the CM ID by returning a non-zero value. */
|
||||
id_priv->cm_id.ib = NULL;
|
||||
cma_exch(id_priv, CMA_DESTROYING);
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
rdma_destroy_id(&id_priv->id);
|
||||
return ret;
|
||||
}
|
||||
out:
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -2570,8 +2560,8 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast)
|
||||
int ret;
|
||||
|
||||
id_priv = mc->id_priv;
|
||||
if (cma_disable_remove(id_priv, CMA_ADDR_BOUND) &&
|
||||
cma_disable_remove(id_priv, CMA_ADDR_RESOLVED))
|
||||
if (cma_disable_callback(id_priv, CMA_ADDR_BOUND) &&
|
||||
cma_disable_callback(id_priv, CMA_ADDR_RESOLVED))
|
||||
return 0;
|
||||
|
||||
mutex_lock(&id_priv->qp_mutex);
|
||||
@ -2596,12 +2586,12 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast)
|
||||
ret = id_priv->id.event_handler(&id_priv->id, &event);
|
||||
if (ret) {
|
||||
cma_exch(id_priv, CMA_DESTROYING);
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
rdma_destroy_id(&id_priv->id);
|
||||
return 0;
|
||||
}
|
||||
|
||||
cma_enable_remove(id_priv);
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -2760,6 +2750,7 @@ static int cma_remove_id_dev(struct rdma_id_private *id_priv)
|
||||
{
|
||||
struct rdma_cm_event event;
|
||||
enum cma_state state;
|
||||
int ret = 0;
|
||||
|
||||
/* Record that we want to remove the device */
|
||||
state = cma_exch(id_priv, CMA_DEVICE_REMOVAL);
|
||||
@ -2767,15 +2758,18 @@ static int cma_remove_id_dev(struct rdma_id_private *id_priv)
|
||||
return 0;
|
||||
|
||||
cma_cancel_operation(id_priv, state);
|
||||
wait_event(id_priv->wait_remove, !atomic_read(&id_priv->dev_remove));
|
||||
mutex_lock(&id_priv->handler_mutex);
|
||||
|
||||
/* Check for destruction from another callback. */
|
||||
if (!cma_comp(id_priv, CMA_DEVICE_REMOVAL))
|
||||
return 0;
|
||||
goto out;
|
||||
|
||||
memset(&event, 0, sizeof event);
|
||||
event.event = RDMA_CM_EVENT_DEVICE_REMOVAL;
|
||||
return id_priv->id.event_handler(&id_priv->id, &event);
|
||||
ret = id_priv->id.event_handler(&id_priv->id, &event);
|
||||
out:
|
||||
mutex_unlock(&id_priv->handler_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void cma_process_remove(struct cma_device *cma_dev)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user