Re: [2.4.21]: nbd ksymoops-report

[Paul Clements <Paul.Clements@SteelEye.com>]

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Paul Clements wrote:
> 
> On Thu, 7 Aug 2003, Bernd Schubert wrote:
> 
> > every time when nbd-client disconnects a nbd-device the decoded oops
> > from below will happen.
> > This only happens after we upgraded from 2.4.20 to 2.4.21,
> > so I guess the backported update from 2.5.50 causes this.

[snip]
 
> This corresponds to the following source:
> 
> lo->sock->ops->shutdown(lo->sock, SEND_SHUTDOWN|RCV_SHUTDOWN);
> 
> Somehow, lo->sock is NULL here. The only way I see that this could

Alright, looking back over the nbd-client source I now see what's going
on. You're calling "nbd-client -d" to manually disconnect?


> Would you be willing to test a patch against 2.4.21?

If you're willing to test the attached patch, I'd be grateful. Otherwise
I'll test it in the next few days and forward on to Marcelo...


Thanks,
Paul

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--- linux-2.4.21-PRISTINE/drivers/block/nbd.c	2003-06-13 10:51:32.000000000 -0400
+++ linux-2.4.21/drivers/block/nbd.c	2003-08-07 13:24:48.000000000 -0400
@@ -428,23 +428,24 @@ static int nbd_ioctl(struct inode *inode
                 return 0 ;
  
 	case NBD_CLEAR_SOCK:
+		error = 0;
+		down(&lo->tx_lock);
+		lo->sock = NULL;
+		up(&lo->tx_lock);
+		spin_lock(&lo->queue_lock);
+		file = lo->file;
+		lo->file = NULL;
+		spin_unlock(&lo->queue_lock);
 		nbd_clear_que(lo);
 		spin_lock(&lo->queue_lock);
 		if (!list_empty(&lo->queue_head)) {
-			spin_unlock(&lo->queue_lock);
-			printk(KERN_ERR "nbd: Some requests are in progress -> can not turn off.\n");
-			return -EBUSY;
+			printk(KERN_ERR "nbd: disconnect: some requests are in progress -> please try again.\n");
+			error = -EBUSY;
 		}
-		file = lo->file;
-		if (!file) {
-			spin_unlock(&lo->queue_lock);
-			return -EINVAL;
-		}
-		lo->file = NULL;
-		lo->sock = NULL;
 		spin_unlock(&lo->queue_lock);
-		fput(file);
-		return 0;
+		if (file)
+			fput(file);
+		return error;
 	case NBD_SET_SOCK:
 		if (lo->file)
 			return -EBUSY;