--- linux-2.4.16/drivers/block/nbd.c.orig	Fri Oct 26 18:39:02 2001
+++ linux-2.4.16/drivers/block/nbd.c	Thu Dec  6 17:50:32 2001
@@ -24,7 +24,9 @@
  * 01-3-11 Make nbd work with new Linux block layer code. It now supports
  *   plugging like all the other block devices. Also added in MSG_MORE to
  *   reduce number of partial TCP segments sent. <steve@chygwyn.com>
- *
+ * 01-12-06 Make nbd cleanly killable; fix some locking issues; acknowledge
+ *   and log network errors; make default device size 2TB.
+ *   <James.Bottomley@SteelEye.com> <Paul.Clements@SteelEye.com>
  * possible FIXME: make set_sock / set_blksize / set_size / do_it one syscall
  * why not: would need verify_area and friends, would share yet another 
  *          structure with userland
@@ -94,18 +96,10 @@
 	int result;
 	struct msghdr msg;
 	struct iovec iov;
-	unsigned long flags;
-	sigset_t oldset;
 
 	oldfs = get_fs();
 	set_fs(get_ds());
 
-	spin_lock_irqsave(&current->sigmask_lock, flags);
-	oldset = current->blocked;
-	sigfillset(&current->blocked);
-	recalc_sigpending(current);
-	spin_unlock_irqrestore(&current->sigmask_lock, flags);
-
 
 	do {
 		sock->sk->allocation = GFP_NOIO;
@@ -125,6 +119,12 @@
 		else
 			result = sock_recvmsg(sock, &msg, size, 0);
 
+		if(signal_pending(current)) {
+			printk(KERN_WARNING "NBD caught signal\n");
+			result = -EINTR;
+			break;
+		}
+
 		if (result <= 0) {
 #ifdef PARANOIA
 			printk(KERN_ERR "NBD: %s - sock=%ld at buf=%ld, size=%d returned %d.\n",
@@ -136,11 +136,6 @@
 		buf += result;
 	} while (size > 0);
 
-	spin_lock_irqsave(&current->sigmask_lock, flags);
-	current->blocked = oldset;
-	recalc_sigpending(current);
-	spin_unlock_irqrestore(&current->sigmask_lock, flags);
-
 	set_fs(oldfs);
 	return result;
 }
@@ -336,8 +331,27 @@
 		spin_unlock_irq(&io_request_lock);
 
 		down (&lo->queue_lock);
+		if(!lo->file) {
+			up(&lo->queue_lock);
+			spin_lock_irq(&io_request_lock);
+			printk(KERN_ERR "NBD: fail between accept and semaphore, file lost\n");
+			req->errors++;
+			nbd_end_request(req);
+			continue;
+		}
+		
 		list_add(&req->queue, &lo->queue_head);
 		nbd_send_req(lo->sock, req);	/* Why does this block?         */
+		if(req->errors) {
+			printk(KERN_ERR "NBD: nbd_send_req failed\n");
+			list_del(&req->queue);
+
+			up(&lo->queue_lock);
+			spin_lock_irq(&io_request_lock);
+			nbd_end_request(req);
+
+			continue;
+		}
 		up (&lo->queue_lock);
 
 		spin_lock_irq(&io_request_lock);
@@ -387,12 +401,14 @@
 			printk(KERN_ERR "nbd: Some requests are in progress -> can not turn off.\n");
 			return -EBUSY;
 		}
-		up(&lo->queue_lock);
 		file = lo->file;
-		if (!file)
+		if (!file) {
+			up(&lo->queue_lock);
 			return -EINVAL;
+		}
 		lo->file = NULL;
 		lo->sock = NULL;
+		up(&lo->queue_lock);
 		fput(file);
 		return 0;
 	case NBD_SET_SOCK:
@@ -433,9 +449,29 @@
 		if (!lo->file)
 			return -EINVAL;
 		nbd_do_it(lo);
+		/* on return tidy up in case we have a signal */
+		printk(KERN_WARNING "NBD: nbd_do_it returned\n");
+		/* Forcibly shutdown the socket causing all listeners
+		 * to error
+		 *
+		 * FIXME: This code is duplicated from sys_shutdown, but
+		 * there should be a more generic interface rather than
+		 * calling socket ops directly here */
+		lo->sock->ops->shutdown(lo->sock, 2);
+		down(&lo->queue_lock);
+		printk(KERN_WARNING "NBD: lock acquired\n");
+		nbd_clear_que(lo);
+		file = lo->file;
+		lo->file = NULL;
+		lo->sock = NULL;
+		up(&lo->queue_lock);
+		if(file)
+			fput(file);
 		return lo->harderror;
 	case NBD_CLEAR_QUE:
+		down(&lo->queue_lock);
 		nbd_clear_que(lo);
+		up(&lo->queue_lock);
 		return 0;
 #ifdef PARANOIA
 	case NBD_PRINT_DEBUG:
@@ -512,7 +548,7 @@
 		init_MUTEX(&nbd_dev[i].queue_lock);
 		nbd_blksizes[i] = 1024;
 		nbd_blksize_bits[i] = 10;
-		nbd_bytesizes[i] = 0x7ffffc00; /* 2GB */
+		nbd_bytesizes[i] = ((u64)0x7ffffc00) << 10; /* 2TB */
 		nbd_sizes[i] = nbd_bytesizes[i] >> BLOCK_SIZE_BITS;
 		register_disk(NULL, MKDEV(MAJOR_NR,i), 1, &nbd_fops,
 				nbd_bytesizes[i]>>9);