On Mon, 4 Jul 2011, Heiko Carstens wrote: > On Sat, Jul 02, 2011 at 01:37:59PM -0400, Alan Stern wrote: > > The second bug, which hit me but apparently not any of you, is that the > > request_queue's elevator gets deallocated while it is still in use. > > That's because __scsi_remove_device() calls scsi_free_queue(), which > > does blk_cleanup_queue(), which calls elevator_exit(), even though the > > device file is still open and more requests will be submitted when the > > file is closed. > > > > I'm not sure of the right fix for this. One possibility is to move the > > scsi_free_queue() call to scsi_device_dev_release_usercontext(). Or > > maybe the elevator_exit() call should be moved to blk_release_queue(). > > > > Also, I have no idea why this shows up with USB drives but not other > > SCSI transports. A fluke of timing? > > FWIW, I reported a bug where the request_queue's elevator got deallocated > while it was still in use (fc transport with device hotplug): > > http://www.spinics.net/lists/linux-scsi/msg52879.html That does sound like the second bug I encountered. Can you reproduce it? Does the patch here: http://marc.info/?l=linux-kernel&m=130963676907731&w=2 fix the problem? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
