Re: [dm-devel] [PATCH] dm-bufio

[Joe Thornber <thornber redhat com>]

On Fri, Oct 14, 2011 at 03:14:34PM -0400, Mikulas Patocka wrote:
@@ -999,15 +1013,19 @@ again:
                 * someone is doing some writes simultaneously with us --- in
                 * this case, stop dropping the lock.
                 */
                if (dropped_lock)
                        goto again;
        }
        wake_up(&c->free_buffer_wait);
        dm_bufio_unlock(c);

-       a = xchg(&c->async_write_error, 0);
+       if (likely(!c->async_write_error))
+               a = 0;
+       else
+               a = xchg(&c->async_write_error, 0);
        f = dm_bufio_issue_flush(c);


I didn't change this.  Is it also fixing a preexisting issue?