From bf4c63252490ba78fb833cc7acf1a5b1900c970f Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Wed, 14 Dec 2011 22:54:12 -0200 Subject: [PATCH] Bluetooth: convert conn hash to RCU Handling hci_conn_hash with RCU make us avoid some locking and disable tasklets. Acked-by: Marcel Holtmann Signed-off-by: Gustavo F. Padovan --- 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 14b200b08d84..e83243318924 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 b04467674a13..5e9e193ac71e 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 2c4f32f44569..de923ee60093 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2050,7 +2050,10 @@ 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; @@ -2068,6 +2071,8 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int break; } + rcu_read_unlock(); + if (conn) { int cnt, q; @@ -2103,14 +2108,18 @@ 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, @@ -2124,7 +2133,9 @@ 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) @@ -2135,8 +2146,6 @@ 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; @@ -2161,12 +2170,12 @@ 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; @@ -2200,7 +2209,9 @@ 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) @@ -2211,8 +2222,6 @@ 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; @@ -2234,11 +2243,12 @@ 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) -- 2.34.1