From: "Gustavo F. Padovan" <padovan@xxxxxxxxxxxxxx>
Handling hci_conn_hash with RCU make us avoid some locking and disable
tasklets.
Signed-off-by: Gustavo F. Padovan <padovan@xxxxxxxxxxxxxx>
---
include/net/bluetooth/hci_core.h | 45 ++++++++++++++++++++++++++-----------
net/bluetooth/hci_conn.c | 19 +++++++--------
net/bluetooth/hci_core.c | 34 ++++++++++++++++++----------
3 files changed, 62 insertions(+), 36 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 14b200b..e832433 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -392,7 +392,7 @@ static inline void hci_conn_hash_init(struct hci_dev *hdev)
static inline void hci_conn_hash_add(struct hci_dev *hdev, struct hci_conn *c)
{
struct hci_conn_hash *h = &hdev->conn_hash;
- list_add(&c->list, &h->list);
+ list_add_rcu(&c->list, &h->list);
switch (c->type) {
case ACL_LINK:
h->acl_num++;
@@ -410,7 +410,10 @@ static inline void hci_conn_hash_add(struct hci_dev *hdev, struct hci_conn *c)
static inline void hci_conn_hash_del(struct hci_dev *hdev, struct hci_conn *c)
{
struct hci_conn_hash *h = &hdev->conn_hash;
- list_del(&c->list);
+
+ list_del_rcu(&c->list);
+ synchronize_rcu();
+
switch (c->type) {
case ACL_LINK:
h->acl_num--;
@@ -445,14 +448,18 @@ static inline struct hci_conn *hci_conn_hash_lookup_handle(struct hci_dev *hdev,
__u16 handle)
{
struct hci_conn_hash *h = &hdev->conn_hash;
- struct list_head *p;
struct hci_conn *c;
- list_for_each(p, &h->list) {
- c = list_entry(p, struct hci_conn, list);
- if (c->handle == handle)
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->handle == handle) {
+ rcu_read_unlock();
return c;
+ }
}
+ rcu_read_unlock();
+
return NULL;
}
@@ -460,14 +467,19 @@ static inline struct hci_conn *hci_conn_hash_lookup_ba(struct hci_dev *hdev,
__u8 type, bdaddr_t *ba)
{
struct hci_conn_hash *h = &hdev->conn_hash;
- struct list_head *p;
struct hci_conn *c;
- list_for_each(p, &h->list) {
- c = list_entry(p, struct hci_conn, list);
- if (c->type == type && !bacmp(&c->dst, ba))
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->type == type && !bacmp(&c->dst, ba)) {
+ rcu_read_unlock();
return c;
+ }
}
+
+ rcu_read_unlock();
+
return NULL;
}
@@ -475,14 +487,19 @@ static inline struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev,
__u8 type, __u16 state)
{
struct hci_conn_hash *h = &hdev->conn_hash;
- struct list_head *p;
struct hci_conn *c;
- list_for_each(p, &h->list) {
- c = list_entry(p, struct hci_conn, list);
- if (c->type == type && c->state == state)
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->type == type && c->state == state) {
+ rcu_read_unlock();
return c;
+ }
}
+
+ rcu_read_unlock();
+
return NULL;
}
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index b044676..5e9e193 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -418,18 +418,17 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
hci_dev_hold(hdev);
- tasklet_disable(&hdev->tx_task);
-
hci_conn_hash_add(hdev, conn);
- if (hdev->notify)
+ if (hdev->notify) {
+ tasklet_disable(&hdev->tx_task);
hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
+ tasklet_enable(&hdev->tx_task);
+ }
atomic_set(&conn->devref, 0);
hci_conn_init_sysfs(conn);
- tasklet_enable(&hdev->tx_task);
-
return conn;
}
@@ -465,15 +464,15 @@ int hci_conn_del(struct hci_conn *conn)
}
}
- tasklet_disable(&hdev->tx_task);
hci_chan_list_flush(conn);
hci_conn_hash_del(hdev, conn);
- if (hdev->notify)
+ if (hdev->notify) {
+ tasklet_disable(&hdev->tx_task);
hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
-
- tasklet_enable(&hdev->tx_task);
+ tasklet_enable(&hdev->tx_task);
+ }
skb_queue_purge(&conn->data_q);
@@ -808,7 +807,7 @@ void hci_conn_hash_flush(struct hci_dev *hdev)
BT_DBG("hdev %s", hdev->name);
- list_for_each_entry(c, &h->list, list) {
+ list_for_each_entry_rcu(c, &h->list, list) {
c->state = BT_CLOSED;
hci_proto_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index f016a40..7654777 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2051,7 +2051,10 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int
/* We don't have to lock device here. Connections are always
* added and removed with TX task disabled. */
- list_for_each_entry(c, &h->list, list) {
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
if (c->type != type || skb_queue_empty(&c->data_q))
continue;
@@ -2069,6 +2072,8 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int
break;
}
+ rcu_read_unlock();
+
if (conn) {
int cnt, q;
@@ -2104,14 +2109,18 @@ static inline void hci_link_tx_to(struct hci_dev *hdev, __u8 type)
BT_ERR("%s link tx timeout", hdev->name);
+ rcu_read_lock();
+
/* Kill stalled connections */
- list_for_each_entry(c, &h->list, list) {
+ list_for_each_entry_rcu(c, &h->list, list) {
if (c->type == type && c->sent) {
BT_ERR("%s killing stalled connection %s",
hdev->name, batostr(&c->dst));
hci_acl_disconn(c, 0x13);
}
}
+
+ rcu_read_unlock();
}
static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type,
@@ -2125,7 +2134,9 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type,
BT_DBG("%s", hdev->name);
- list_for_each_entry(conn, &h->list, list) {
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(conn, &h->list, list) {
struct hci_chan *tmp;
if (conn->type != type)
@@ -2136,8 +2147,6 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type,
conn_num++;
- rcu_read_lock();
-
list_for_each_entry_rcu(tmp, &conn->chan_list, list) {
struct sk_buff *skb;
@@ -2162,12 +2171,12 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type,
}
}
- rcu_read_unlock();
-
if (hci_conn_num(hdev, type) == conn_num)
break;
}
+ rcu_read_unlock();
+
if (!chan)
return NULL;
@@ -2201,7 +2210,9 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type)
BT_DBG("%s", hdev->name);
- list_for_each_entry(conn, &h->list, list) {
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(conn, &h->list, list) {
struct hci_chan *chan;
if (conn->type != type)
@@ -2212,8 +2223,6 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type)
num++;
- rcu_read_lock();
-
list_for_each_entry_rcu(chan, &conn->chan_list, list) {
struct sk_buff *skb;
@@ -2235,11 +2244,12 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type)
skb->priority);
}
- rcu_read_unlock();
-
if (hci_conn_num(hdev, type) == num)
break;
}
+
+ rcu_read_unlock();
+
}
static inline void hci_sched_acl(struct hci_dev *hdev)
--
1.7.6.4
--
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