Move tcp connection code from user- into kernel-space.
This makes it possible to do TCP reconnect deadlock free.

(This patch requires userspace changes too)

Signed-off-by: Mike Christie <[EMAIL PROTECTED]>
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
---
 drivers/scsi/iscsi_tcp.c |  108 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 83 insertions(+), 25 deletions(-)

Index: linux-2.6/drivers/scsi/iscsi_tcp.c
===================================================================
--- linux-2.6.orig/drivers/scsi/iscsi_tcp.c     2006-09-07 16:00:16.000000000 
+0200
+++ linux-2.6/drivers/scsi/iscsi_tcp.c  2006-09-07 19:32:56.000000000 +0200
@@ -35,6 +35,8 @@
 #include <linux/kfifo.h>
 #include <linux/scatterlist.h>
 #include <linux/mutex.h>
+#include <linux/syscalls.h>
+#include <linux/file.h>
 #include <net/tcp.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_host.h>
@@ -1062,21 +1064,6 @@ iscsi_conn_set_callbacks(struct iscsi_co
        write_unlock_bh(&sk->sk_callback_lock);
 }
 
-static void
-iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
-{
-       struct sock *sk = tcp_conn->sock->sk;
-
-       /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
-       write_lock_bh(&sk->sk_callback_lock);
-       sk->sk_user_data    = NULL;
-       sk->sk_data_ready   = tcp_conn->old_data_ready;
-       sk->sk_state_change = tcp_conn->old_state_change;
-       sk->sk_write_space  = tcp_conn->old_write_space;
-       sk->sk_no_check  = 0;
-       write_unlock_bh(&sk->sk_callback_lock);
-}
-
 /**
  * iscsi_send - generic send routine
  * @sk: kernel's socket
@@ -1741,6 +1728,77 @@ iscsi_tcp_ctask_xmit(struct iscsi_conn *
        return rc;
 }
 
+static int
+iscsi_tcp_ep_connect(struct sockaddr *dst_addr, int non_blocking,
+                    uint64_t *ep_handle)
+{
+       struct socket *sock;
+       int rc, size, arg = 1, window = 524288;
+
+       rc = sock_create_kern(dst_addr->sa_family, SOCK_STREAM, IPPROTO_TCP,
+                             &sock);
+       if (rc < 0) {
+               printk(KERN_ERR "Could not create socket %d.\n", rc);
+               return rc;
+       }
+       sock->sk->sk_allocation = GFP_ATOMIC;
+/*
+       rc = sock->ops->setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
+                                  (char __user *)&arg, sizeof(arg));
+       if (rc) {
+               printk(KERN_ERR "Could not set TCP_NODELAY %d\n", rc);
+               goto release_sock;
+       }
+*/
+       /* should set like nfs */
+       sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+                       (char __user *)&window, sizeof(window));
+       sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
+                       (char __user *)&window, sizeof(window));
+
+       if (dst_addr->sa_family == PF_INET)
+               size = sizeof(struct sockaddr_in);
+       else if (dst_addr->sa_family == PF_INET6)
+               size = sizeof(struct sockaddr_in6);
+       else {
+               rc = -EINVAL;
+               goto release_sock;
+       }
+
+       /* TODO we cannot block here */
+       rc = sock->ops->connect(sock, (struct sockaddr *)dst_addr, size,
+                               0 /*O_NONBLOCK*/);
+       if (rc == -EINPROGRESS)
+               rc = 0;
+       else if (rc) {
+               printk(KERN_ERR "Could not connect %d\n", rc);
+               goto release_sock;
+       }
+
+       rc = sock_map_fd(sock);
+       if (rc < 0)
+               goto release_sock;
+       *ep_handle = (uint64_t)rc;
+       return 0;
+
+release_sock:
+       sock_release(sock);
+       return rc;
+}
+
+static int
+iscsi_tcp_ep_poll(uint64_t ep_handle, int timeout_ms)
+{
+       /* we cheated and blocked on the connect (TODO must fix) */
+       return 1;
+}
+
+static void
+iscsi_tcp_ep_disconnect(uint64_t ep_handle)
+{
+       sys_close(ep_handle);
+}
+
 static struct iscsi_cls_conn *
 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
 {
@@ -1795,11 +1853,7 @@ iscsi_tcp_release_conn(struct iscsi_conn
        if (!tcp_conn->sock)
                return;
 
-       sock_hold(tcp_conn->sock->sk);
-       iscsi_conn_restore_callbacks(tcp_conn);
-       sock_put(tcp_conn->sock->sk);
-
-       sock_release(tcp_conn->sock);
+       fput(tcp_conn->sock->file);
        tcp_conn->sock = NULL;
        conn->recv_lock = NULL;
 }
@@ -1856,10 +1910,13 @@ iscsi_tcp_conn_bind(struct iscsi_cls_ses
                printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
                return -EEXIST;
        }
+       get_file(sock->file);
 
        err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
-       if (err)
+       if (err) {
+               fput(sock->file);
                return err;
+       }
 
        /* bind iSCSI connection and socket */
        tcp_conn->sock = sock;
@@ -2041,13 +2098,11 @@ iscsi_tcp_conn_get_param(struct iscsi_cl
                sk = tcp_conn->sock->sk;
                if (sk->sk_family == PF_INET) {
                        inet = inet_sk(sk);
-                       len = sprintf(buf, "%u.%u.%u.%u\n",
+                       len = sprintf(buf, NIPQUAD_FMT "\n",
                                      NIPQUAD(inet->daddr));
                } else {
                        np = inet6_sk(sk);
-                       len = sprintf(buf,
-                               "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
-                               NIP6(np->daddr));
+                       len = sprintf(buf, NIP6_FMT "\n", NIP6(np->daddr));
                }
                mutex_unlock(&conn->xmitmutex);
                break;
@@ -2185,6 +2240,9 @@ static struct iscsi_transport iscsi_tcp_
        .get_session_param      = iscsi_session_get_param,
        .start_conn             = iscsi_conn_start,
        .stop_conn              = iscsi_tcp_conn_stop,
+       .ep_connect             = iscsi_tcp_ep_connect,
+       .ep_poll                = iscsi_tcp_ep_poll,
+       .ep_disconnect          = iscsi_tcp_ep_disconnect,
        /* IO */
        .send_pdu               = iscsi_conn_send_pdu,
        .get_stats              = iscsi_conn_get_stats,

--

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