On Sun, 11 Oct 2009 15:37:09 +0100 Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote: > On Sun, 11 Oct 2009 15:45:16 +0200 (CEST) > John Kacur <jkacur@xxxxxxxxxx> wrote: > > [linux-scsi cc'd] > > > Locking in ch_open is covered by the spin_lock, it serializes the > > calls to idr_find and scsi_device_get. The BKL appears redundant to > > me here. > > I'm not so sure. In fact there are some quite umm interesting > questions about this code, and some of them are shared with other > modules too. > > Consider the following sequence > > CPU1 CPU2 > register_chrdev > ok > open device > takes lock but open does not take the BKL, so the BKL is not protecting you at all against this.. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
