[SCSI] libiscsi, iser, tcp: remove recv_lock

The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.

We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.

This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 39 insertions, 34 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 7552dd8a88f3..91cb1fd523f0 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -741,7 +741,6 @@ static int
 iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 {
         int rc = 0, opcode, ahslen;
-        struct iscsi_session *session = conn->session;
         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
         struct iscsi_task *task;
 
@@ -770,17 +769,17 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 
         switch(opcode) {
         case ISCSI_OP_SCSI_DATA_IN:
+                spin_lock(&conn->session->lock);
                 task = iscsi_itt_to_ctask(conn, hdr->itt);
                 if (!task)
-                        return ISCSI_ERR_BAD_ITT;
-                if (!task->sc)
-                        return ISCSI_ERR_NO_SCSI_CMD;
+                        rc = ISCSI_ERR_BAD_ITT;
+                else
+                        rc = iscsi_data_rsp(conn, task);
+                if (rc) {
+                        spin_unlock(&conn->session->lock);
+                        break;
+                }
 
-                spin_lock(&conn->session->lock);
-                rc = iscsi_data_rsp(conn, task);
-                spin_unlock(&conn->session->lock);
-                if (rc)
-                        return rc;
                 if (tcp_conn->in.datalen) {
                         struct iscsi_tcp_task *tcp_task = task->dd_data;
                         struct hash_desc *rx_hash = NULL;
@@ -801,15 +800,19 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
                                   "datalen=%d)\n", tcp_conn,
                                   tcp_task->data_offset,
                                   tcp_conn->in.datalen);
-                        return iscsi_segment_seek_sg(&tcp_conn->in.segment,
-                                                     sdb->table.sgl,
-                                                     sdb->table.nents,
-                                                     tcp_task->data_offset,
-                                                     tcp_conn->in.datalen,
-                                                     iscsi_tcp_process_data_in,
-                                                     rx_hash);
+                        rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,
+                                                   sdb->table.sgl,
+                                                   sdb->table.nents,
+                                                   tcp_task->data_offset,
+                                                   tcp_conn->in.datalen,
+                                                   iscsi_tcp_process_data_in,
+                                                   rx_hash);
+                        spin_unlock(&conn->session->lock);
+                        return rc;
                 }
-                /* fall through */
+                rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
+                spin_unlock(&conn->session->lock);
+                break;
         case ISCSI_OP_SCSI_CMD_RSP:
                 if (tcp_conn->in.datalen) {
                         iscsi_tcp_data_recv_prep(tcp_conn);
@@ -818,20 +821,17 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
                 break;
         case ISCSI_OP_R2T:
+                spin_lock(&conn->session->lock);
                 task = iscsi_itt_to_ctask(conn, hdr->itt);
                 if (!task)
-                        return ISCSI_ERR_BAD_ITT;
-                if (!task->sc)
-                        return ISCSI_ERR_NO_SCSI_CMD;
-
-                if (ahslen)
+                        rc = ISCSI_ERR_BAD_ITT;
+                else if (ahslen)
                         rc = ISCSI_ERR_AHSLEN;
-                else if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
-                        spin_lock(&session->lock);
+                else if (task->sc->sc_data_direction == DMA_TO_DEVICE)
                         rc = iscsi_r2t_rsp(conn, task);
-                        spin_unlock(&session->lock);
-                } else
+                else
                         rc = ISCSI_ERR_PROTO;
+                spin_unlock(&conn->session->lock);
                 break;
         case ISCSI_OP_LOGIN_RSP:
         case ISCSI_OP_TEXT_RSP:
@@ -1553,7 +1553,6 @@ iscsi_tcp_release_conn(struct iscsi_conn *conn)
 
         spin_lock_bh(&session->lock);
         tcp_conn->sock = NULL;
-        conn->recv_lock = NULL;
         spin_unlock_bh(&session->lock);
         sockfd_put(sock);
 }
@@ -1578,6 +1577,19 @@ static void
 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 {
         struct iscsi_conn *conn = cls_conn->dd_data;
+        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+
+        /* userspace may have goofed up and not bound us */
+        if (!tcp_conn->sock)
+                return;
+        /*
+         * Make sure our recv side is stopped.
+         * Older tools called conn stop before ep_disconnect
+         * so IO could still be coming in.
+         */
+        write_lock_bh(&tcp_conn->sock->sk->sk_callback_lock);
+        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
+        write_unlock_bh(&tcp_conn->sock->sk->sk_callback_lock);
 
         iscsi_conn_stop(cls_conn, flag);
         iscsi_tcp_release_conn(conn);
@@ -1671,13 +1683,6 @@ iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
         sk->sk_allocation = GFP_ATOMIC;
 
-        /* FIXME: disable Nagle's algorithm */
-
-        /*
-         * Intercept TCP callbacks for sendfile like receive
-         * processing.
-         */
-        conn->recv_lock = &sk->sk_callback_lock;
         iscsi_conn_set_callbacks(conn);
         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
         /*