Re: [PATCH 2/3] [AF_IUCV/IUCV]: Implementation of a skb backlog queue

[David Miller]

From: Frank Pavlic [EMAIL PROTECTED]
Date: Thu, 19 Apr 2007 11:12:14 +0200

 From: Jennifer Hunt [EMAIL PROTECTED]
 
 With the inital implementation we missed to implement a skb backlog
 queue . The result is that socket receive processing tossed packets.
 Since AF_IUCV connections are working synchronously it leads to 
 connection hangs. Problems with read, close and select also
 occured. 
 Using a skb backlog queue is fixing all of these problems .
 
 Signed-off-by: Frank Pavlic [EMAIL PROTECTED]

This won't apply cleanly because of all the sk_buff packet
buffer interface API changes in the current GIT tree.

Can you fix this up and also get a Signoff from Jennifer Hunt?

Thanks a lot!
-
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[PATCH 2/3] [AF_IUCV/IUCV]: Implementation of a skb backlog queue

[Frank Pavlic]

From: Jennifer Hunt [EMAIL PROTECTED]

With the inital implementation we missed to implement a skb backlog
queue . The result is that socket receive processing tossed packets.
Since AF_IUCV connections are working synchronously it leads to 
connection hangs. Problems with read, close and select also
occured. 
Using a skb backlog queue is fixing all of these problems .

Signed-off-by: Frank Pavlic [EMAIL PROTECTED]
---

 include/net/iucv/af_iucv.h |2
 net/iucv/af_iucv.c |  160 -
 2 files changed, 133 insertions(+), 29 deletions(-)

diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h
index 04d1abb..f9bd11b 100644
--- a/include/net/iucv/af_iucv.h
+++ b/include/net/iucv/af_iucv.h
@@ -28,6 +28,7 @@ enum {
IUCV_LISTEN,
IUCV_SEVERED,
IUCV_DISCONN,
+   IUCV_CLOSING,
IUCV_CLOSED
 };
 
@@ -62,6 +63,7 @@ struct iucv_sock {
struct sock *parent;
struct iucv_path*path;
struct sk_buff_head send_skb_q;
+   struct sk_buff_head backlog_skb_q;
unsigned intsend_tag;
 };
 
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index acc9421..0c2e4a8 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -147,6 +147,7 @@ static void iucv_sock_close(struct sock *sk)
unsigned char user_data[16];
struct iucv_sock *iucv = iucv_sk(sk);
int err;
+   unsigned long timeo;
 
iucv_sock_clear_timer(sk);
lock_sock(sk);
@@ -159,6 +160,21 @@ static void iucv_sock_close(struct sock *sk)
case IUCV_CONNECTED:
case IUCV_DISCONN:
err = 0;
+
+   sk-sk_state = IUCV_CLOSING;
+   sk-sk_state_change(sk);
+
+   if(!skb_queue_empty(iucv-send_skb_q)) {
+   if (sock_flag(sk, SOCK_LINGER)  sk-sk_lingertime)
+   timeo = sk-sk_lingertime;
+   else
+   timeo = IUCV_DISCONN_TIMEOUT;
+   err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
+   }
+
+   sk-sk_state = IUCV_CLOSED;
+   sk-sk_state_change(sk);
+
if (iucv-path) {
low_nmcpy(user_data, iucv-src_name);
high_nmcpy(user_data, iucv-dst_name);
@@ -168,12 +184,11 @@ static void iucv_sock_close(struct sock *sk)
iucv-path = NULL;
}
 
-   sk-sk_state = IUCV_CLOSED;
-   sk-sk_state_change(sk);
sk-sk_err = ECONNRESET;
sk-sk_state_change(sk);
 
skb_queue_purge(iucv-send_skb_q);
+   skb_queue_purge(iucv-backlog_skb_q);
 
sock_set_flag(sk, SOCK_ZAPPED);
break;
@@ -204,6 +219,7 @@ static struct sock *iucv_sock_alloc(struct socket *sock, 
int proto, gfp_t prio)
sock_init_data(sock, sk);
INIT_LIST_HEAD(iucv_sk(sk)-accept_q);
skb_queue_head_init(iucv_sk(sk)-send_skb_q);
+   skb_queue_head_init(iucv_sk(sk)-backlog_skb_q);
iucv_sk(sk)-send_tag = 0;
 
sk-sk_destruct = iucv_sock_destruct;
@@ -510,7 +526,7 @@ static int iucv_sock_accept(struct socket *sock, struct 
socket *newsock,
long timeo;
int err = 0;
 
-   lock_sock(sk);
+   lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 
if (sk-sk_state != IUCV_LISTEN) {
err = -EBADFD;
@@ -530,7 +546,7 @@ static int iucv_sock_accept(struct socket *sock, struct 
socket *newsock,
 
release_sock(sk);
timeo = schedule_timeout(timeo);
-   lock_sock(sk);
+   lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 
if (sk-sk_state != IUCV_LISTEN) {
err = -EBADFD;
@@ -606,7 +622,7 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct 
socket *sock,
if(!(skb = sock_alloc_send_skb(sk, len,
   msg-msg_flags  MSG_DONTWAIT,
   err)))
-   return err;
+   goto out;
 
if (memcpy_fromiovec(skb_put(skb, len), msg-msg_iov, len)){
err = -EFAULT;
@@ -647,10 +663,16 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct 
socket *sock,
 {
int noblock = flags  MSG_DONTWAIT;
struct sock *sk = sock-sk;
+   struct iucv_sock *iucv = iucv_sk(sk);
int target, copied = 0;
-   struct sk_buff *skb;
+   struct sk_buff *skb, *rskb, *cskb;
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))
+   return 0;
+
if (flags  (MSG_OOB))
return -EOPNOTSUPP;
 
@@ -665,10 +687,12 @@ static int