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[PATCH net-next v4 2/3] vsock: Move lingering logic to af_vsock core

Michal Luczaj posted 3 patches 9 months, 2 weeks ago
There is a newer version of this series
[PATCH net-next v4 2/3] vsock: Move lingering logic to af_vsock core
Posted by Michal Luczaj 9 months, 2 weeks ago 
Lingering should be transport-independent in the long run. In preparation
for supporting other transports, as well the linger on shutdown(), move
code to core.

Generalize by querying vsock_transport::unsent_bytes(), guard against the
callback being unimplemented. Do not pass sk_lingertime explicitly. Pull
SOCK_LINGER check into vsock_linger().

Flatten the function. Remove the nested block by inverting the condition:
return early on !timeout.

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
---
 include/net/af_vsock.h                  |  1 +
 net/vmw_vsock/af_vsock.c                | 30 ++++++++++++++++++++++++++++++
 net/vmw_vsock/virtio_transport_common.c | 23 ++---------------------
 3 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 9e85424c834353d016a527070dd62e15ff3bfce1..d56e6e135158939087d060dfcf65d3fdaea53bf3 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -221,6 +221,7 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport,
 				     void (*fn)(struct sock *sk));
 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
 bool vsock_find_cid(unsigned int cid);
+void vsock_linger(struct sock *sk);
 
 /**** TAP ****/
 
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index fc6afbc8d6806a4d98c66abc3af4bd139c583b08..a31ad6b141cd38d1806df4b5d417924bb8607e32 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1013,6 +1013,36 @@ static int vsock_getname(struct socket *sock,
 	return err;
 }
 
+void vsock_linger(struct sock *sk)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	ssize_t (*unsent)(struct vsock_sock *vsk);
+	struct vsock_sock *vsk = vsock_sk(sk);
+	long timeout;
+
+	if (!sock_flag(sk, SOCK_LINGER))
+		return;
+
+	timeout = sk->sk_lingertime;
+	if (!timeout)
+		return;
+
+	/* unsent_bytes() may be unimplemented. */
+	unsent = vsk->transport->unsent_bytes;
+	if (!unsent)
+		return;
+
+	add_wait_queue(sk_sleep(sk), &wait);
+
+	do {
+		if (sk_wait_event(sk, &timeout, unsent(vsk) == 0, &wait))
+			break;
+	} while (!signal_pending(current) && timeout);
+
+	remove_wait_queue(sk_sleep(sk), &wait);
+}
+EXPORT_SYMBOL_GPL(vsock_linger);
+
 static int vsock_shutdown(struct socket *sock, int mode)
 {
 	int err;
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 045ac53f69735e1979162aea8c9ab5961407640c..aa308f285bf1bcf4c689407033de854c6f85a639 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1192,25 +1192,6 @@ static void virtio_transport_remove_sock(struct vsock_sock *vsk)
 	vsock_remove_sock(vsk);
 }
 
-static void virtio_transport_wait_close(struct sock *sk, long timeout)
-{
-	if (timeout) {
-		DEFINE_WAIT_FUNC(wait, woken_wake_function);
-		struct vsock_sock *vsk = vsock_sk(sk);
-
-		add_wait_queue(sk_sleep(sk), &wait);
-
-		do {
-			if (sk_wait_event(sk, &timeout,
-					  virtio_transport_unsent_bytes(vsk) == 0,
-					  &wait))
-				break;
-		} while (!signal_pending(current) && timeout);
-
-		remove_wait_queue(sk_sleep(sk), &wait);
-	}
-}
-
 static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,
 					       bool cancel_timeout)
 {
@@ -1280,8 +1261,8 @@ static bool virtio_transport_close(struct vsock_sock *vsk)
 	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
 		(void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
 
-	if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
-		virtio_transport_wait_close(sk, sk->sk_lingertime);
+	if (!(current->flags & PF_EXITING))
+		vsock_linger(sk);
 
 	if (sock_flag(sk, SOCK_DONE)) {
 		return true;

-- 
2.49.0
Re: [PATCH net-next v4 2/3] vsock: Move lingering logic to af_vsock core
Posted by Stefano Garzarella 9 months, 1 week ago 
On Thu, May 01, 2025 at 10:05:23AM +0200, Michal Luczaj wrote:
>Lingering should be transport-independent in the long run. In preparation
>for supporting other transports, as well the linger on shutdown(), move
>code to core.
>
>Generalize by querying vsock_transport::unsent_bytes(), guard against the
>callback being unimplemented. Do not pass sk_lingertime explicitly. Pull
>SOCK_LINGER check into vsock_linger().
>
>Flatten the function. Remove the nested block by inverting the condition:
>return early on !timeout.
>
>Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
>Signed-off-by: Michal Luczaj <mhal@rbox.co>
>---
> include/net/af_vsock.h                  |  1 +
> net/vmw_vsock/af_vsock.c                | 30 ++++++++++++++++++++++++++++++
> net/vmw_vsock/virtio_transport_common.c | 23 ++---------------------
> 3 files changed, 33 insertions(+), 21 deletions(-)
>
>diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>index 9e85424c834353d016a527070dd62e15ff3bfce1..d56e6e135158939087d060dfcf65d3fdaea53bf3 100644
>--- a/include/net/af_vsock.h
>+++ b/include/net/af_vsock.h
>@@ -221,6 +221,7 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport,
> 				     void (*fn)(struct sock *sk));
> int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock 
> *psk);
> bool vsock_find_cid(unsigned int cid);
>+void vsock_linger(struct sock *sk);
>
> /**** TAP ****/
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index fc6afbc8d6806a4d98c66abc3af4bd139c583b08..a31ad6b141cd38d1806df4b5d417924bb8607e32 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -1013,6 +1013,36 @@ static int vsock_getname(struct socket *sock,
> 	return err;
> }
>
>+void vsock_linger(struct sock *sk)
>+{
>+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
>+	ssize_t (*unsent)(struct vsock_sock *vsk);
>+	struct vsock_sock *vsk = vsock_sk(sk);
>+	long timeout;
>+
>+	if (!sock_flag(sk, SOCK_LINGER))
>+		return;
>+
>+	timeout = sk->sk_lingertime;
>+	if (!timeout)
>+		return;
>+
>+	/* unsent_bytes() may be unimplemented. */

This comment IMO should be enriched, as it is now it doesn't add much to 
the code. I'm thinking on something like this:
     Transports must implement `unsent_bytes` if they want to support
     SOCK_LINGER through `vsock_linger()` since we use it to check when
     the socket can be closed.

The rest LGTM!

Thanks,
Stefano

>+	unsent = vsk->transport->unsent_bytes;
>+	if (!unsent)
>+		return;
>+
>+	add_wait_queue(sk_sleep(sk), &wait);
>+
>+	do {
>+		if (sk_wait_event(sk, &timeout, unsent(vsk) == 0, &wait))
>+			break;
>+	} while (!signal_pending(current) && timeout);
>+
>+	remove_wait_queue(sk_sleep(sk), &wait);
>+}
>+EXPORT_SYMBOL_GPL(vsock_linger);
>+
> static int vsock_shutdown(struct socket *sock, int mode)
> {
> 	int err;
>diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>index 
>045ac53f69735e1979162aea8c9ab5961407640c..aa308f285bf1bcf4c689407033de854c6f85a639 
>100644
>--- a/net/vmw_vsock/virtio_transport_common.c
>+++ b/net/vmw_vsock/virtio_transport_common.c
>@@ -1192,25 +1192,6 @@ static void virtio_transport_remove_sock(struct vsock_sock *vsk)
> 	vsock_remove_sock(vsk);
> }
>
>-static void virtio_transport_wait_close(struct sock *sk, long timeout)
>-{
>-	if (timeout) {
>-		DEFINE_WAIT_FUNC(wait, woken_wake_function);
>-		struct vsock_sock *vsk = vsock_sk(sk);
>-
>-		add_wait_queue(sk_sleep(sk), &wait);
>-
>-		do {
>-			if (sk_wait_event(sk, &timeout,
>-					  virtio_transport_unsent_bytes(vsk) == 0,
>-					  &wait))
>-				break;
>-		} while (!signal_pending(current) && timeout);
>-
>-		remove_wait_queue(sk_sleep(sk), &wait);
>-	}
>-}
>-
> static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,
> 					       bool cancel_timeout)
> {
>@@ -1280,8 +1261,8 @@ static bool virtio_transport_close(struct vsock_sock *vsk)
> 	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
> 		(void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
>
>-	if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
>-		virtio_transport_wait_close(sk, sk->sk_lingertime);
>+	if (!(current->flags & PF_EXITING))
>+		vsock_linger(sk);
>
> 	if (sock_flag(sk, SOCK_DONE)) {
> 		return true;
>
>-- 
>2.49.0
>
Re: [PATCH net-next v4 2/3] vsock: Move lingering logic to af_vsock core
Posted by Michal Luczaj 9 months, 1 week ago 
On 5/6/25 11:53, Stefano Garzarella wrote:
> On Thu, May 01, 2025 at 10:05:23AM +0200, Michal Luczaj wrote:
>> Lingering should be transport-independent in the long run. In preparation
>> for supporting other transports, as well the linger on shutdown(), move
>> code to core.
>>
>> Generalize by querying vsock_transport::unsent_bytes(), guard against the
>> callback being unimplemented. Do not pass sk_lingertime explicitly. Pull
>> SOCK_LINGER check into vsock_linger().
>>
>> Flatten the function. Remove the nested block by inverting the condition:
>> return early on !timeout.
>>
>> Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
>> Signed-off-by: Michal Luczaj <mhal@rbox.co>
>> ---
>> include/net/af_vsock.h                  |  1 +
>> net/vmw_vsock/af_vsock.c                | 30 ++++++++++++++++++++++++++++++
>> net/vmw_vsock/virtio_transport_common.c | 23 ++---------------------
>> 3 files changed, 33 insertions(+), 21 deletions(-)
>>
>> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>> index 9e85424c834353d016a527070dd62e15ff3bfce1..d56e6e135158939087d060dfcf65d3fdaea53bf3 100644
>> --- a/include/net/af_vsock.h
>> +++ b/include/net/af_vsock.h
>> @@ -221,6 +221,7 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport,
>> 				     void (*fn)(struct sock *sk));
>> int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock 
>> *psk);
>> bool vsock_find_cid(unsigned int cid);
>> +void vsock_linger(struct sock *sk);
>>
>> /**** TAP ****/
>>
>> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>> index fc6afbc8d6806a4d98c66abc3af4bd139c583b08..a31ad6b141cd38d1806df4b5d417924bb8607e32 100644
>> --- a/net/vmw_vsock/af_vsock.c
>> +++ b/net/vmw_vsock/af_vsock.c
>> @@ -1013,6 +1013,36 @@ static int vsock_getname(struct socket *sock,
>> 	return err;
>> }
>>
>> +void vsock_linger(struct sock *sk)
>> +{
>> +	DEFINE_WAIT_FUNC(wait, woken_wake_function);
>> +	ssize_t (*unsent)(struct vsock_sock *vsk);
>> +	struct vsock_sock *vsk = vsock_sk(sk);
>> +	long timeout;
>> +
>> +	if (!sock_flag(sk, SOCK_LINGER))
>> +		return;
>> +
>> +	timeout = sk->sk_lingertime;
>> +	if (!timeout)
>> +		return;
>> +
>> +	/* unsent_bytes() may be unimplemented. */
> 
> This comment IMO should be enriched, as it is now it doesn't add much to 
> the code. I'm thinking on something like this:
>      Transports must implement `unsent_bytes` if they want to support
>      SOCK_LINGER through `vsock_linger()` since we use it to check when
>      the socket can be closed.

OK, will do.

Thanks,
Michal

Patchew 2.1-devel-b67e4c2

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