Bluetooth: Use struct list_head for L2CAP channels list

Use a well known Kernel API is always a good idea than implement your own
list.
In the future we might use RCU on this list.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 6378bcc94e2ba135ccf6a0c4489d4ee4cd98ab61..ddf4bc56a5b56d268ed401b79b552e14fc838231 100644 (file)
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -277,16 +277,9 @@ struct l2cap_conn_param_update_rsp {
 #define L2CAP_CONN_PARAM_REJECTED      0x0001
 
 /* ----- L2CAP channels and connections ----- */
-
 struct l2cap_chan {
        struct sock *sk;
-       struct l2cap_chan       *next_c;
-       struct l2cap_chan       *prev_c;
-};
-
-struct l2cap_chan_list {
-       struct l2cap_chan *head;
-       rwlock_t        lock;
+       struct list_head list;
 };
 
 struct l2cap_conn {
@@ -312,7 +305,8 @@ struct l2cap_conn {
 
        __u8            disc_reason;
 
-       struct l2cap_chan_list chan_list;
+       struct list_head chan_l;
+       rwlock_t        chan_lock;
 };
 
 struct sock_del_list {

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index e49d8f7b80a551ed8812e38ee1c783f13f605fb4..0dbbaf394c1397a00647088f8c2fc03741f34c27 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -74,66 +74,75 @@ static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
 static int l2cap_ertm_data_rcv(struct sock *sk, struct sk_buff *skb);
 
 /* ---- L2CAP channels ---- */
-static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_chan_list *l, u16 cid)
+static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, u16 cid)
 {
        struct l2cap_chan *c;
-       for (c = l->head; c; c = c->next_c) {
-               if (l2cap_pi(c->sk)->dcid == cid)
-                       break;
+
+       list_for_each_entry(c, &conn->chan_l, list) {
+               struct sock *s = c->sk;
+               if (l2cap_pi(s)->dcid == cid)
+                       return c;
        }
-       return c;
+       return NULL;
+
 }
 
-static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_chan_list *l, u16 cid)
+static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 cid)
 {
        struct l2cap_chan *c;
-       for (c = l->head; c; c = c->next_c) {
-               if (l2cap_pi(c->sk)->scid == cid)
-                       break;
+
+       list_for_each_entry(c, &conn->chan_l, list) {
+               struct sock *s = c->sk;
+               if (l2cap_pi(s)->scid == cid)
+                       return c;
        }
-       return c;
+       return NULL;
 }
 
 /* Find channel with given SCID.
  * Returns locked socket */
-static inline struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_chan_list *l, u16 cid)
+static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 cid)
 {
        struct l2cap_chan *c;
-       read_lock(&l->lock);
-       c = __l2cap_get_chan_by_scid(l, cid);
+
+       read_lock(&conn->chan_lock);
+       c = __l2cap_get_chan_by_scid(conn, cid);
        if (c)
                bh_lock_sock(c->sk);
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
        return c;
 }
 
-static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_chan_list *l, u8 ident)
+static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
 {
        struct l2cap_chan *c;
-       for (c = l->head; c; c = c->next_c) {
-               if (l2cap_pi(c->sk)->ident == ident)
-                       break;
+
+       list_for_each_entry(c, &conn->chan_l, list) {
+               struct sock *s = c->sk;
+               if (l2cap_pi(s)->ident == ident)
+                       return c;
        }
-       return c;
+       return NULL;
 }
 
-static inline struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_chan_list *l, u8 ident)
+static inline struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
 {
        struct l2cap_chan *c;
-       read_lock(&l->lock);
-       c = __l2cap_get_chan_by_ident(l, ident);
+
+       read_lock(&conn->chan_lock);
+       c = __l2cap_get_chan_by_ident(conn, ident);
        if (c)
                bh_lock_sock(c->sk);
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
        return c;
 }
 
-static u16 l2cap_alloc_cid(struct l2cap_chan_list *l)
+static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
 {
        u16 cid = L2CAP_CID_DYN_START;
 
        for (; cid < L2CAP_CID_DYN_END; cid++) {
-               if (!__l2cap_get_chan_by_scid(l, cid))
+               if (!__l2cap_get_chan_by_scid(conn, cid))
                        return cid;
        }
 
@@ -153,38 +162,8 @@ static struct l2cap_chan *l2cap_chan_alloc(struct sock *sk)
        return chan;
 }
 
-static inline void __l2cap_chan_link(struct l2cap_chan_list *l, struct l2cap_chan *chan)
-{
-       sock_hold(chan->sk);
-
-       if (l->head)
-               l->head->prev_c = chan;
-
-       chan->next_c = l->head;
-       chan->prev_c = NULL;
-       l->head = chan;
-}
-
-static inline void l2cap_chan_unlink(struct l2cap_chan_list *l, struct l2cap_chan *chan)
-{
-       struct l2cap_chan *next = chan->next_c, *prev = chan->prev_c;
-
-       write_lock_bh(&l->lock);
-       if (chan == l->head)
-               l->head = next;
-
-       if (next)
-               next->prev_c = prev;
-       if (prev)
-               prev->next_c = next;
-       write_unlock_bh(&l->lock);
-
-       __sock_put(chan->sk);
-}
-
 static void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 {
-       struct l2cap_chan_list *l = &conn->chan_list;
        struct sock *sk = chan->sk;
 
        BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
@@ -202,7 +181,7 @@ static void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
                        l2cap_pi(sk)->dcid = L2CAP_CID_LE_DATA;
                } else {
                        /* Alloc CID for connection-oriented socket */
-                       l2cap_pi(sk)->scid = l2cap_alloc_cid(l);
+                       l2cap_pi(sk)->scid = l2cap_alloc_cid(conn);
                        l2cap_pi(sk)->omtu = L2CAP_DEFAULT_MTU;
                }
        } else if (sk->sk_type == SOCK_DGRAM) {
@@ -217,7 +196,9 @@ static void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
                l2cap_pi(sk)->omtu = L2CAP_DEFAULT_MTU;
        }
 
-       __l2cap_chan_link(l, chan);
+       sock_hold(sk);
+
+       list_add(&chan->list, &conn->chan_l);
 }
 
 /* Delete channel.
@@ -233,8 +214,12 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
        BT_DBG("sk %p, conn %p, err %d", sk, conn, err);
 
        if (conn) {
-               /* Unlink from channel list */
-               l2cap_chan_unlink(&conn->chan_list, chan);
+               /* Delete from channel list */
+               write_lock_bh(&conn->chan_lock);
+               list_del(&chan->list);
+               write_unlock_bh(&conn->chan_lock);
+               __sock_put(sk);
+
                l2cap_pi(sk)->conn = NULL;
                hci_conn_put(conn->hcon);
        }
@@ -502,7 +487,6 @@ void l2cap_send_disconn_req(struct l2cap_conn *conn, struct sock *sk, int err)
 /* ---- L2CAP connections ---- */
 static void l2cap_conn_start(struct l2cap_conn *conn)
 {
-       struct l2cap_chan_list *l = &conn->chan_list;
        struct sock_del_list del, *tmp1, *tmp2;
        struct l2cap_chan *chan;
 
@@ -510,10 +494,11 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 
        INIT_LIST_HEAD(&del.list);
 
-       read_lock(&l->lock);
+       read_lock(&conn->chan_lock);
 
-       for (chan = l->head; chan; chan = chan->next_c) {
+       list_for_each_entry(chan, &conn->chan_l, list) {
                struct sock *sk = chan->sk;
+
                bh_lock_sock(sk);
 
                if (sk->sk_type != SOCK_SEQPACKET &&
@@ -593,7 +578,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
                bh_unlock_sock(sk);
        }
 
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
 
        list_for_each_entry_safe(tmp1, tmp2, &del.list, list) {
                bh_lock_sock(tmp1->sk);
@@ -638,7 +623,6 @@ static struct sock *l2cap_get_sock_by_scid(int state, __le16 cid, bdaddr_t *src)
 
 static void l2cap_le_conn_ready(struct l2cap_conn *conn)
 {
-       struct l2cap_chan_list *list = &conn->chan_list;
        struct sock *parent, *uninitialized_var(sk);
        struct l2cap_chan *chan;
 
@@ -666,11 +650,12 @@ static void l2cap_le_conn_ready(struct l2cap_conn *conn)
                goto clean;
        }
 
-       write_lock_bh(&list->lock);
+       write_lock_bh(&conn->chan_lock);
 
        hci_conn_hold(conn->hcon);
 
        l2cap_sock_init(sk, parent);
+
        bacpy(&bt_sk(sk)->src, conn->src);
        bacpy(&bt_sk(sk)->dst, conn->dst);
 
@@ -685,7 +670,7 @@ static void l2cap_le_conn_ready(struct l2cap_conn *conn)
        sk->sk_state = BT_CONNECTED;
        parent->sk_data_ready(parent, 0);
 
-       write_unlock_bh(&list->lock);
+       write_unlock_bh(&conn->chan_lock);
 
 clean:
        bh_unlock_sock(parent);
@@ -693,7 +678,6 @@ clean:
 
 static void l2cap_conn_ready(struct l2cap_conn *conn)
 {
-       struct l2cap_chan_list *l = &conn->chan_list;
        struct l2cap_chan *chan;
 
        BT_DBG("conn %p", conn);
@@ -701,10 +685,11 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
        if (!conn->hcon->out && conn->hcon->type == LE_LINK)
                l2cap_le_conn_ready(conn);
 
-       read_lock(&l->lock);
+       read_lock(&conn->chan_lock);
 
-       for (chan = l->head; chan; chan = chan->next_c) {
+       list_for_each_entry(chan, &conn->chan_l, list) {
                struct sock *sk = chan->sk;
+
                bh_lock_sock(sk);
 
                if (conn->hcon->type == LE_LINK) {
@@ -724,26 +709,26 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
                bh_unlock_sock(sk);
        }
 
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
 }
 
 /* Notify sockets that we cannot guaranty reliability anymore */
 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
 {
-       struct l2cap_chan_list *l = &conn->chan_list;
        struct l2cap_chan *chan;
 
        BT_DBG("conn %p", conn);
 
-       read_lock(&l->lock);
+       read_lock(&conn->chan_lock);
 
-       for (chan = l->head; chan; chan = chan->next_c) {
+       list_for_each_entry(chan, &conn->chan_l, list) {
                struct sock *sk = chan->sk;
+
                if (l2cap_pi(sk)->force_reliable)
                        sk->sk_err = err;
        }
 
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
 }
 
 static void l2cap_info_timeout(unsigned long arg)
@@ -783,7 +768,9 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon, u8 status)
        conn->feat_mask = 0;
 
        spin_lock_init(&conn->lock);
-       rwlock_init(&conn->chan_list.lock);
+       rwlock_init(&conn->chan_lock);
+
+       INIT_LIST_HEAD(&conn->chan_l);
 
        if (hcon->type != LE_LINK)
                setup_timer(&conn->info_timer, l2cap_info_timeout,
@@ -797,7 +784,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon, u8 status)
 static void l2cap_conn_del(struct hci_conn *hcon, int err)
 {
        struct l2cap_conn *conn = hcon->l2cap_data;
-       struct l2cap_chan *chan;
+       struct l2cap_chan *chan, *l;
        struct sock *sk;
 
        if (!conn)
@@ -808,7 +795,7 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
        kfree_skb(conn->rx_skb);
 
        /* Kill channels */
-       while ((chan = conn->chan_list.head)) {
+       list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
                sk = chan->sk;
                bh_lock_sock(sk);
                l2cap_chan_del(chan, err);
@@ -825,10 +812,9 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 
 static inline void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 {
-       struct l2cap_chan_list *l = &conn->chan_list;
-       write_lock_bh(&l->lock);
+       write_lock_bh(&conn->chan_lock);
        __l2cap_chan_add(conn, chan);
-       write_unlock_bh(&l->lock);
+       write_unlock_bh(&conn->chan_lock);
 }
 
 /* ---- Socket interface ---- */
@@ -1426,14 +1412,13 @@ static void l2cap_chan_ready(struct sock *sk)
 /* Copy frame to all raw sockets on that connection */
 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
 {
-       struct l2cap_chan_list *l = &conn->chan_list;
        struct sk_buff *nskb;
        struct l2cap_chan *chan;
 
        BT_DBG("conn %p", conn);
 
-       read_lock(&l->lock);
-       for (chan = l->head; chan; chan = chan->next_c) {
+       read_lock(&conn->chan_lock);
+       list_for_each_entry(chan, &conn->chan_l, list) {
                struct sock *sk = chan->sk;
                if (sk->sk_type != SOCK_RAW)
                        continue;
@@ -1448,7 +1433,7 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
                if (sock_queue_rcv_skb(sk, nskb))
                        kfree_skb(nskb);
        }
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
 }
 
 /* ---- L2CAP signalling commands ---- */
@@ -2015,7 +2000,6 @@ static inline int l2cap_command_rej(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u8 *data)
 {
-       struct l2cap_chan_list *list = &conn->chan_list;
        struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
        struct l2cap_conn_rsp rsp;
        struct l2cap_chan *chan;
@@ -2062,11 +2046,11 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
                goto response;
        }
 
-       write_lock_bh(&list->lock);
+       write_lock_bh(&conn->chan_lock);
 
        /* Check if we already have channel with that dcid */
-       if (__l2cap_get_chan_by_dcid(list, scid)) {
-               write_unlock_bh(&list->lock);
+       if (__l2cap_get_chan_by_dcid(conn, scid)) {
+               write_unlock_bh(&conn->chan_lock);
                sock_set_flag(sk, SOCK_ZAPPED);
                l2cap_sock_kill(sk);
                goto response;
@@ -2115,7 +2099,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
                status = L2CAP_CS_NO_INFO;
        }
 
-       write_unlock_bh(&list->lock);
+       write_unlock_bh(&conn->chan_lock);
 
 response:
        bh_unlock_sock(parent);
@@ -2169,11 +2153,11 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
        BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x", dcid, scid, result, status);
 
        if (scid) {
-               chan = l2cap_get_chan_by_scid(&conn->chan_list, scid);
+               chan = l2cap_get_chan_by_scid(conn, scid);
                if (!chan)
                        return -EFAULT;
        } else {
-               chan = l2cap_get_chan_by_ident(&conn->chan_list, cmd->ident);
+               chan = l2cap_get_chan_by_ident(conn, cmd->ident);
                if (!chan)
                        return -EFAULT;
        }
@@ -2243,7 +2227,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 
        BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
 
-       chan = l2cap_get_chan_by_scid(&conn->chan_list, dcid);
+       chan = l2cap_get_chan_by_scid(conn, dcid);
        if (!chan)
                return -ENOENT;
 
@@ -2338,7 +2322,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x",
                        scid, flags, result);
 
-       chan = l2cap_get_chan_by_scid(&conn->chan_list, scid);
+       chan = l2cap_get_chan_by_scid(conn, scid);
        if (!chan)
                return 0;
 
@@ -2418,7 +2402,7 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 
        BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
 
-       chan = l2cap_get_chan_by_scid(&conn->chan_list, dcid);
+       chan = l2cap_get_chan_by_scid(conn, dcid);
        if (!chan)
                return 0;
 
@@ -2458,7 +2442,7 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 
        BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
 
-       chan = l2cap_get_chan_by_scid(&conn->chan_list, scid);
+       chan = l2cap_get_chan_by_scid(conn, scid);
        if (!chan)
                return 0;
 
@@ -3612,7 +3596,7 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
        u8 tx_seq;
        int len;
 
-       chan = l2cap_get_chan_by_scid(&conn->chan_list, cid);
+       chan = l2cap_get_chan_by_scid(conn, cid);
        if (!chan) {
                BT_DBG("unknown cid 0x%4.4x", cid);
                goto drop;
@@ -3855,21 +3839,19 @@ static inline void l2cap_check_encryption(struct sock *sk, u8 encrypt)
 
 static int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 {
-       struct l2cap_chan_list *l;
        struct l2cap_conn *conn = hcon->l2cap_data;
        struct l2cap_chan *chan;
 
        if (!conn)
                return 0;
 
-       l = &conn->chan_list;
-
        BT_DBG("conn %p", conn);
 
-       read_lock(&l->lock);
+       read_lock(&conn->chan_lock);
 
-       for (chan = l->head; chan; chan = chan->next_c) {
+       list_for_each_entry(chan, &conn->chan_l, list) {
                struct sock *sk = chan->sk;
+
                bh_lock_sock(sk);
 
                if (l2cap_pi(sk)->conf_state & L2CAP_CONF_CONNECT_PEND) {
@@ -3923,7 +3905,7 @@ static int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
                bh_unlock_sock(sk);
        }
 
-       read_unlock(&l->lock);
+       read_unlock(&conn->chan_lock);
 
        return 0;
 }
@@ -3980,7 +3962,7 @@ static int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 fl
                        goto drop;
                }
 
-               chan = l2cap_get_chan_by_scid(&conn->chan_list, cid);
+               chan = l2cap_get_chan_by_scid(conn, cid);
 
                if (chan && chan->sk) {
                        struct sock *sk = chan->sk;