+cifsFYI functions as a bit mask. Setting it to 1 enables additional kernel
+logging of various informational messages. 2 enables logging of non-zero
+SMB return codes while 4 enables logging of requests that take longer
+than one second to complete (except for byte range lock requests).
+Setting it to 4 requires defining CONFIG_CIFS_STATS2 manually in the
+source code (typically by setting it in the beginning of cifsglob.h),
+and setting it to seven enables all three. Finally, tracing
+the start of smb requests and responses can be enabled via: