Bluetooth: Simplify packet copy in hci_send_to_monitor function

Within the monitor functionality, the global atomic variable called
monitor_promisc ensures that no memory allocation happend when there
is actually no client listening. This means it is safe to just create
a copy of the skb since it is guaranteed that at least one client
exists. No extra checks needed.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index e176a988625ec41241ff8b4fe70d89ee1fda0257..026e84a8065949ac16084681c957df2aded98d9f 100644 (file)
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -221,6 +221,7 @@ void hci_send_to_monitor(struct hci_dev *hdev, struct sk_buff *skb)
 {
        struct sock *sk;
        struct sk_buff *skb_copy = NULL;
+       struct hci_mon_hdr *hdr;
        __le16 opcode;
 
        if (!atomic_read(&monitor_promisc))
@@ -251,6 +252,17 @@ void hci_send_to_monitor(struct hci_dev *hdev, struct sk_buff *skb)
                return;
        }
 
+       /* Create a private copy with headroom */
+       skb_copy = __pskb_copy_fclone(skb, HCI_MON_HDR_SIZE, GFP_ATOMIC, true);
+       if (!skb_copy)
+               return;
+
+       /* Put header before the data */
+       hdr = (void *) skb_push(skb_copy, HCI_MON_HDR_SIZE);
+       hdr->opcode = opcode;
+       hdr->index = cpu_to_le16(hdev->id);
+       hdr->len = cpu_to_le16(skb->len);
+
        read_lock(&hci_sk_list.lock);
 
        sk_for_each(sk, &hci_sk_list.head) {
@@ -262,22 +274,6 @@ void hci_send_to_monitor(struct hci_dev *hdev, struct sk_buff *skb)
                if (hci_pi(sk)->channel != HCI_CHANNEL_MONITOR)
                        continue;
 
-               if (!skb_copy) {
-                       struct hci_mon_hdr *hdr;
-
-                       /* Create a private copy with headroom */
-                       skb_copy = __pskb_copy_fclone(skb, HCI_MON_HDR_SIZE,
-                                                     GFP_ATOMIC, true);
-                       if (!skb_copy)
-                               continue;
-
-                       /* Put header before the data */
-                       hdr = (void *) skb_push(skb_copy, HCI_MON_HDR_SIZE);
-                       hdr->opcode = opcode;
-                       hdr->index = cpu_to_le16(hdev->id);
-                       hdr->len = cpu_to_le16(skb->len);
-               }
-
                nskb = skb_clone(skb_copy, GFP_ATOMIC);
                if (!nskb)
                        continue;