[RFCv2 3/4] Bluetooth: Use ERR_PTR to return error from hci_connect

[RFCv2 3/4] Bluetooth: Use ERR_PTR to return error from hci_connect

[anderson.briglia]

From: Ville Tervo <ville.tervo@nokia.com>

Use ERR_PRT mechanism to return error from hci_connect. This patch also
includes a change to return error if LE link exists already to remote host.

Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
---
 net/bluetooth/hci_conn.c   |   12 +++++++-----
 net/bluetooth/l2cap_core.c |   10 ++++------
 net/bluetooth/sco.c        |    6 +++---
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index ee7dcdd..e06b856 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -305,7 +305,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 
 	conn = kzalloc(sizeof(struct hci_conn), GFP_ATOMIC);
 	if (!conn)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	bacpy(&conn->dst, dst);
 	conn->hdev  = hdev;
@@ -459,8 +459,10 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
 		le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
 		if (!le)
 			le = hci_conn_add(hdev, LE_LINK, dst);
-		if (!le)
-			return NULL;
+		else
+			return ERR_PTR(-EBUSY);
+		if (IS_ERR(le))
+			return le;
 		if (le->state == BT_OPEN)
 			hci_le_connect(le);
 
@@ -472,8 +474,8 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
 	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
 	if (!acl) {
 		acl = hci_conn_add(hdev, ACL_LINK, dst);
-		if (!acl)
-			return NULL;
+		if (IS_ERR(acl))
+			return acl;
 	}
 
 	hci_conn_hold(acl);
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 7f30c53..f85be1a 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -869,7 +869,7 @@ int l2cap_do_connect(struct sock *sk)
 	struct hci_conn *hcon;
 	struct hci_dev *hdev;
 	__u8 auth_type;
-	int err;
+	int err = 0;
 
 	BT_DBG("%s -> %s psm 0x%2.2x", batostr(src), batostr(dst),
 							l2cap_pi(sk)->psm);
@@ -880,8 +880,6 @@ int l2cap_do_connect(struct sock *sk)
 
 	hci_dev_lock_bh(hdev);
 
-	err = -ENOMEM;
-
 	auth_type = l2cap_get_auth_type(sk);
 
 	if (l2cap_pi(sk)->dcid == L2CAP_CID_LE_DATA)
@@ -891,8 +889,10 @@ int l2cap_do_connect(struct sock *sk)
 		hcon = hci_connect(hdev, ACL_LINK, dst,
 					l2cap_pi(sk)->sec_level, auth_type);
 
-	if (!hcon)
+	if (IS_ERR(hcon)) {
+		err = PTR_ERR(hcon);
 		goto done;
+	}
 
 	conn = l2cap_conn_add(hcon, 0);
 	if (!conn) {
@@ -900,8 +900,6 @@ int l2cap_do_connect(struct sock *sk)
 		goto done;
 	}
 
-	err = 0;
-
 	/* Update source addr of the socket */
 	bacpy(src, conn->src);
 
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index c9348dd..26f2f04 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -190,16 +190,16 @@ static int sco_connect(struct sock *sk)
 
 	hci_dev_lock_bh(hdev);
 
-	err = -ENOMEM;
-
 	if (lmp_esco_capable(hdev) && !disable_esco)
 		type = ESCO_LINK;
 	else
 		type = SCO_LINK;
 
 	hcon = hci_connect(hdev, type, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING);
-	if (!hcon)
+	if (IS_ERR(hcon)) {
+		err = PTR_ERR(hcon);
 		goto done;
+	}
 
 	conn = sco_conn_add(hcon, 0);
 	if (!conn) {
-- 
1.7.1

Re: [RFCv2 3/4] Bluetooth: Use ERR_PTR to return error from hci_connect

[Gustavo F. Padovan]

Hi Ville,

* anderson.briglia@openbossa.org <anderson.briglia@openbossa.org> [2011-02-17 10:39:55 -0300]:

> From: Ville Tervo <ville.tervo@nokia.com>
> 
> Use ERR_PRT mechanism to return error from hci_connect. This patch also

Typo here, ERR_PTR.

> includes a change to return error if LE link exists already to remote host.
> 
> Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
> ---
>  net/bluetooth/hci_conn.c   |   12 +++++++-----
>  net/bluetooth/l2cap_core.c |   10 ++++------
>  net/bluetooth/sco.c        |    6 +++---
>  3 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
> index ee7dcdd..e06b856 100644
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -305,7 +305,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
>  
>  	conn = kzalloc(sizeof(struct hci_conn), GFP_ATOMIC);
>  	if (!conn)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);

That's not really need. Seems that return NULL here means ENOMEM.

>  
>  	bacpy(&conn->dst, dst);
>  	conn->hdev  = hdev;
> @@ -459,8 +459,10 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
>  		le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
>  		if (!le)
>  			le = hci_conn_add(hdev, LE_LINK, dst);
> -		if (!le)
> -			return NULL;
> +		else
> +			return ERR_PTR(-EBUSY);
> +		if (IS_ERR(le))
> +			return le;

I prefer this instead:

                le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
                if (le)
                        return ERR_PTR(-EBUSY);

                le = hci_conn_add(hdev, LE_LINK, dst);
                if (!le)
                        return ERR_PTR(-ENOMEM);

Regards,

-- 
Gustavo F. Padovan
http://profusion.mobi

Re: [RFCv2 3/4] Bluetooth: Use ERR_PTR to return error from hci_connect

[Anderson Lizardo]

Hi Gustavo,

On Thu, Feb 17, 2011 at 2:25 PM, Gustavo F. Padovan
<padovan@profusion.mobi> wrote:
>> @@ -459,8 +459,10 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
>>               le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
>>               if (!le)
>>                       le = hci_conn_add(hdev, LE_LINK, dst);
>> -             if (!le)
>> -                     return NULL;
>> +             else
>> +                     return ERR_PTR(-EBUSY);
>> +             if (IS_ERR(le))
>> +                     return le;
>
> I prefer this instead:
>
>                le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
>                if (le)
>                        return ERR_PTR(-EBUSY);
>
>                le = hci_conn_add(hdev, LE_LINK, dst);
>                if (!le)
>                        return ERR_PTR(-ENOMEM);

I think the code above (besides the "if (le)" typo) is not equivalent
to the original one. See:

>>               le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
>>               if (!le)
>>                       le = hci_conn_add(hdev, LE_LINK, dst);
>> -             if (!le)
>> -                     return NULL;

if hci_conn_hash_lookup_ba() returns NULL, it should call
hci_conn_add(), and if that fails, then return NULL (or some
ERR_PTR()).

Regards,
-- 
Anderson Lizardo
Instituto Nokia de Tecnologia - INdT
Manaus - Brazil

Re: [RFCv2 3/4] Bluetooth: Use ERR_PTR to return error from hci_connect

[Anderson Lizardo]

Hi Briglia,

On Thu, Feb 17, 2011 at 10:39 AM,  <anderson.briglia@openbossa.org> wrote:
> @@ -472,8 +474,8 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
>        acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
>        if (!acl) {
>                acl = hci_conn_add(hdev, ACL_LINK, dst);
> -               if (!acl)
> -                       return NULL;
> +               if (IS_ERR(acl))
> +                       return acl;
>        }

Note that if you follow Gustavo's suggestion to keep hci_conn_add()
returning NULL on ENOMEM, you should change this as well:

if (!acl)
    return ERR_PTR(-ENOMEM);

Regards,
-- 
Anderson Lizardo
Instituto Nokia de Tecnologia - INdT
Manaus - Brazil