[PATCH 15/21] iscsi: kernel side tcp connect

Peter Zijlstra
2006-09-06T13:16:45Z

[-- Attachment #1: iscsi_ep_connect.patch --]
[-- Type: text/plain, Size: 8306 bytes --]

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

(This patch requires userspace changes too)

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
drivers/scsi/iscsi_tcp.c | 128 +++++++++++++++++++++++-------------
drivers/scsi/iscsi_tcp.h | 2
drivers/scsi/libiscsi.c | 6 -
drivers/scsi/scsi_transport_iscsi.c | 4 -
include/scsi/libiscsi.h | 4 -
include/scsi/scsi_transport_iscsi.h | 2
6 files changed, 93 insertions(+), 53 deletions(-)

Index: linux-2.6/drivers/scsi/iscsi_tcp.c
===================================================================
--- linux-2.6.orig/drivers/scsi/iscsi_tcp.c
+++ linux-2.6/drivers/scsi/iscsi_tcp.c
@@ -904,7 +904,7 @@ more:
goto again;
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return 0;
- }
+ }

memcpy(&recv_digest, conn->data, sizeof(uint32_t));
if (recv_digest != tcp_conn->in.datadgst) {
@@ -1062,21 +1062,6 @@ 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
@@ -1304,7 +1289,7 @@ iscsi_tcp_cmd_init(struct iscsi_cmd_task
debug_scsi("cmd [itt 0x%x total %d imm_data %d "
"unsol count %d, unsol offset %d]\n",
ctask->itt, ctask->total_length, ctask->imm_count,
- ctask->unsol_count, ctask->unsol_offset);
+ ctask->unsol_count, ctask->unsol_offset);
} else
tcp_ctask->xmstate = XMSTATE_R_HDR;

@@ -1455,7 +1440,7 @@ iscsi_send_padding(struct iscsi_conn *co
tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_PAD;
debug_scsi("sending %d pad bytes for itt 0x%x\n",
- tcp_ctask->pad_count, ctask->itt);
+ tcp_ctask->pad_count, ctask->itt);
rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
&sent);
if (rc) {
@@ -1484,7 +1469,7 @@ iscsi_send_digest(struct iscsi_conn *con
iscsi_buf_init_iov(buf, (char*)digest, 4);
}
tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
-
+
rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
if (!rc)
debug_scsi("sent digest 0x%x for itt 0x%x\n", *digest,
@@ -1593,7 +1578,7 @@ send_hdr:
int start = tcp_ctask->sent;

rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
- &tcp_ctask->sent, &ctask->data_count,
+ &tcp_ctask->sent, &ctask->data_count,
&dtask->digestbuf, &dtask->digest);
ctask->unsol_count -= tcp_ctask->sent - start;
if (rc)
@@ -1741,6 +1726,79 @@ 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;
+ }
+
+ *ep_handle = (uint64_t)(unsigned long)sock;
+ 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)
+{
+ struct socket *sock;
+
+ sock = (struct socket *)(unsigned long)ep_handle;
+ if (!sock)
+ return;
+ sock_release(sock);
+}
+
static struct iscsi_cls_conn *
iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
{
@@ -1788,23 +1846,6 @@ tcp_conn_alloc_fail:
}

static void
-iscsi_tcp_release_conn(struct iscsi_conn *conn)
-{
- struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
-
- 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);
- tcp_conn->sock = NULL;
- conn->recv_lock = NULL;
-}
-
-static void
iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
{
struct iscsi_conn *conn = cls_conn->dd_data;
@@ -1814,7 +1855,6 @@ iscsi_tcp_conn_destroy(struct iscsi_cls_
if (conn->hdrdgst_en || conn->datadgst_en)
digest = 1;

- iscsi_tcp_release_conn(conn);
iscsi_conn_teardown(cls_conn);

/* now free tcp_conn */
@@ -1835,7 +1875,6 @@ iscsi_tcp_conn_stop(struct iscsi_cls_con
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;

iscsi_conn_stop(cls_conn, flag);
- iscsi_tcp_release_conn(conn);
tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
}

@@ -2041,13 +2080,11 @@ 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 +2222,9 @@ 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,
Index: linux-2.6/drivers/scsi/libiscsi.c
===================================================================
--- linux-2.6.orig/drivers/scsi/libiscsi.c
+++ linux-2.6/drivers/scsi/libiscsi.c
struct iscsi_session *
class_to_transport_session(struct iscsi_cls_session *cls_session)
@@ -1609,7 +1609,7 @@ int iscsi_conn_start(struct iscsi_cls_co
return -EPERM;
}

- if ((session->imm_data_en || !session->initial_r2t_en) &&
+ if ((session->imm_data_en || !session->initial_r2t_en) &&
session->first_burst > session->max_burst) {
printk("iscsi: invalid burst lengths: "
"first_burst %d max_burst %d\n",
Index: linux-2.6/include/scsi/libiscsi.h
===================================================================
--- linux-2.6.orig/include/scsi/libiscsi.h
+++ linux-2.6/include/scsi/libiscsi.h
@@ -76,7 +76,7 @@ struct iscsi_mgmt_task {
* Becuae LLDs allocate their hdr differently, this is a pointer to
* that storage. It must be setup at session creation time.
*/
- struct iscsi_hdr *hdr;
+ struct iscsi_hdr *hdr;
char *data; /* mgmt payload */
int data_count; /* counts data to be sent */
uint32_t itt; /* this ITT */