Re: report bug: System reboots when accessing a loop-device over a second loop-device with 2.4.2-ac7

[Jens Axboe]

On Fri, Mar 02 2001, Mario Hermann wrote:
> There is another small bug with the loop over loop problem. Now it works
> fine for
> files but not for Devices:
> 
> losetup /dev/loop0 /dev/sr1
> losetup /dev/loop1 /dev/loop0
> dd if=/dev/loop1 of=test.dat bs=2048 count=1024

Pending miscount, this should fix it.

-- 
Jens Axboe


--- /opt/kernel/linux-2.4.2-ac8/drivers/block/loop.c    Fri Mar  2 14:48:24 2001
+++ drivers/block/loop.c        Fri Mar  2 16:27:31 2001
@@ -307,6 +307,7 @@
                lo->lo_bh = lo->lo_bhtail = bh;
        spin_unlock_irqrestore(&lo->lo_lock, flags);
 
+       atomic_inc(&lo->lo_pending);
        up(&lo->lo_bh_mutex);
 }
 
@@ -404,7 +405,6 @@
        spin_lock_irq(&lo->lo_lock);
        if (lo->lo_state != Lo_bound)
                goto inactive;
-       atomic_inc(&lo->lo_pending);
        spin_unlock_irq(&lo->lo_lock);
 
        if (rw == WRITE) {
@@ -452,8 +452,6 @@
        return 0;
 
 err:
-       if (atomic_dec_and_test(&lo->lo_pending))
-               up(&lo->lo_bh_mutex);
        loop_put_buffer(bh);
 out:
        buffer_IO_error(rbh);