[AF_IUCV]: postpone receival of iucv-packets
AF_IUCV socket programs may waste Linux storage, because af_iucv
allocates an skb whenever posted by the receive callback routine and
receives the message immediately.
Message receival is now postponed if data from previous callbacks has
not yet been transferred to the receiving socket program. Instead a
message handle is saved in a message queue as a reminder. Once
messages could be given to the receiving socket program, there is
an additional checking for entries in the message queue, followed
by skb allocation and message receival if applicable.
Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 6535872..43e01c8 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -224,6 +224,8 @@
INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
spin_lock_init(&iucv_sk(sk)->accept_q_lock);
skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
+ INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
+ spin_lock_init(&iucv_sk(sk)->message_q.lock);
skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
iucv_sk(sk)->send_tag = 0;
@@ -673,6 +675,90 @@
return err;
}
+static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
+{
+ int dataleft, size, copied = 0;
+ struct sk_buff *nskb;
+
+ dataleft = len;
+ while (dataleft) {
+ if (dataleft >= sk->sk_rcvbuf / 4)
+ size = sk->sk_rcvbuf / 4;
+ else
+ size = dataleft;
+
+ nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
+ if (!nskb)
+ return -ENOMEM;
+
+ memcpy(nskb->data, skb->data + copied, size);
+ copied += size;
+ dataleft -= size;
+
+ skb_reset_transport_header(nskb);
+ skb_reset_network_header(nskb);
+ nskb->len = size;
+
+ skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
+ }
+
+ return 0;
+}
+
+static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
+ struct iucv_path *path,
+ struct iucv_message *msg)
+{
+ int rc;
+
+ if (msg->flags & IPRMDATA) {
+ skb->data = NULL;
+ skb->len = 0;
+ } else {
+ rc = iucv_message_receive(path, msg, 0, skb->data,
+ msg->length, NULL);
+ if (rc) {
+ kfree_skb(skb);
+ return;
+ }
+ if (skb->truesize >= sk->sk_rcvbuf / 4) {
+ rc = iucv_fragment_skb(sk, skb, msg->length);
+ kfree_skb(skb);
+ skb = NULL;
+ if (rc) {
+ iucv_path_sever(path, NULL);
+ return;
+ }
+ skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
+ } else {
+ skb_reset_transport_header(skb);
+ skb_reset_network_header(skb);
+ skb->len = msg->length;
+ }
+ }
+
+ if (sock_queue_rcv_skb(sk, skb))
+ skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
+}
+
+static void iucv_process_message_q(struct sock *sk)
+{
+ struct iucv_sock *iucv = iucv_sk(sk);
+ struct sk_buff *skb;
+ struct sock_msg_q *p, *n;
+
+ list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
+ skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
+ if (!skb)
+ break;
+ iucv_process_message(sk, skb, p->path, &p->msg);
+ list_del(&p->list);
+ kfree(p);
+ if (!skb_queue_empty(&iucv->backlog_skb_q))
+ break;
+ }
+}
+
static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
@@ -684,8 +770,9 @@
int err = 0;
if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
- skb_queue_empty(&iucv->backlog_skb_q) &&
- skb_queue_empty(&sk->sk_receive_queue))
+ skb_queue_empty(&iucv->backlog_skb_q) &&
+ skb_queue_empty(&sk->sk_receive_queue) &&
+ list_empty(&iucv->message_q.list))
return 0;
if (flags & (MSG_OOB))
@@ -724,16 +811,23 @@
kfree_skb(skb);
/* Queue backlog skbs */
- rskb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
+ rskb = skb_dequeue(&iucv->backlog_skb_q);
while (rskb) {
if (sock_queue_rcv_skb(sk, rskb)) {
- skb_queue_head(&iucv_sk(sk)->backlog_skb_q,
+ skb_queue_head(&iucv->backlog_skb_q,
rskb);
break;
} else {
- rskb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
+ rskb = skb_dequeue(&iucv->backlog_skb_q);
}
}
+ if (skb_queue_empty(&iucv->backlog_skb_q)) {
+ spin_lock_bh(&iucv->message_q.lock);
+ if (!list_empty(&iucv->message_q.list))
+ iucv_process_message_q(sk);
+ spin_unlock_bh(&iucv->message_q.lock);
+ }
+
} else
skb_queue_head(&sk->sk_receive_queue, skb);
@@ -975,99 +1069,44 @@
sk->sk_state_change(sk);
}
-static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len,
- struct sk_buff_head *fragmented_skb_q)
-{
- int dataleft, size, copied = 0;
- struct sk_buff *nskb;
-
- dataleft = len;
- while (dataleft) {
- if (dataleft >= sk->sk_rcvbuf / 4)
- size = sk->sk_rcvbuf / 4;
- else
- size = dataleft;
-
- nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
- if (!nskb)
- return -ENOMEM;
-
- memcpy(nskb->data, skb->data + copied, size);
- copied += size;
- dataleft -= size;
-
- skb_reset_transport_header(nskb);
- skb_reset_network_header(nskb);
- nskb->len = size;
-
- skb_queue_tail(fragmented_skb_q, nskb);
- }
-
- return 0;
-}
-
static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
{
struct sock *sk = path->private;
struct iucv_sock *iucv = iucv_sk(sk);
- struct sk_buff *skb, *fskb;
- struct sk_buff_head fragmented_skb_q;
- int rc;
-
- skb_queue_head_init(&fragmented_skb_q);
+ struct sk_buff *skb;
+ struct sock_msg_q *save_msg;
+ int len;
if (sk->sk_shutdown & RCV_SHUTDOWN)
return;
+ if (!list_empty(&iucv->message_q.list) ||
+ !skb_queue_empty(&iucv->backlog_skb_q))
+ goto save_message;
+
+ len = atomic_read(&sk->sk_rmem_alloc);
+ len += msg->length + sizeof(struct sk_buff);
+ if (len > sk->sk_rcvbuf)
+ goto save_message;
+
skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
- if (!skb) {
- iucv_path_sever(path, NULL);
- return;
- }
+ if (!skb)
+ goto save_message;
- if (msg->flags & IPRMDATA) {
- skb->data = NULL;
- skb->len = 0;
- } else {
- rc = iucv_message_receive(path, msg, 0, skb->data,
- msg->length, NULL);
- if (rc) {
- kfree_skb(skb);
- return;
- }
- if (skb->truesize >= sk->sk_rcvbuf / 4) {
- rc = iucv_fragment_skb(sk, skb, msg->length,
- &fragmented_skb_q);
- kfree_skb(skb);
- skb = NULL;
- if (rc) {
- iucv_path_sever(path, NULL);
- return;
- }
- } else {
- skb_reset_transport_header(skb);
- skb_reset_network_header(skb);
- skb->len = msg->length;
- }
- }
- /* Queue the fragmented skb */
- fskb = skb_dequeue(&fragmented_skb_q);
- while (fskb) {
- if (!skb_queue_empty(&iucv->backlog_skb_q))
- skb_queue_tail(&iucv->backlog_skb_q, fskb);
- else if (sock_queue_rcv_skb(sk, fskb))
- skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, fskb);
- fskb = skb_dequeue(&fragmented_skb_q);
- }
+ spin_lock(&iucv->message_q.lock);
+ iucv_process_message(sk, skb, path, msg);
+ spin_unlock(&iucv->message_q.lock);
- /* Queue the original skb if it exists (was not fragmented) */
- if (skb) {
- if (!skb_queue_empty(&iucv->backlog_skb_q))
- skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
- else if (sock_queue_rcv_skb(sk, skb))
- skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
- }
+ return;
+save_message:
+ save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
+ save_msg->path = path;
+ save_msg->msg = *msg;
+
+ spin_lock(&iucv->message_q.lock);
+ list_add_tail(&save_msg->list, &iucv->message_q.list);
+ spin_unlock(&iucv->message_q.lock);
}
static void iucv_callback_txdone(struct iucv_path *path,