From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 12207] block reads/writes > 122880 bytes to USB tape drive gives EBUSY Date: Sat, 11 Apr 2009 14:26:01 GMT Message-ID: <200904111426.n3BEQ1bl032734@demeter.kernel.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Received: from demeter.kernel.org ([140.211.167.39]:37057 "EHLO demeter.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756697AbZDKO0G (ORCPT ); Sat, 11 Apr 2009 10:26:06 -0400 Received: from demeter.kernel.org (localhost.localdomain [127.0.0.1]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n3BEQ1No032735 for ; Sat, 11 Apr 2009 14:26:01 GMT In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org http://bugzilla.kernel.org/show_bug.cgi?id=12207 --- Comment #32 from Alan Stern 2009-04-11 14:26:00 --- > Yes, SCSI uses the (Linux) block layer and the attributes do exist within > the kernel. They just are not visible in sysfs for character devices. Last > night I read the code to find out why. Your analysis is correct but it > only shows that the kobject exists. The kobject is added to sysfs using > kobject_add() in blk_register_queue() called by add_disk(), which is only > called by disk drivers. You are right. And this makes me feel better -- I had thought that usb-storage's max_sectors attribute was redundant. Now I know that for some SCSI-over-USB devices, the information is not accessible anywhere else. > Whether character devices should add the kobject somewhere in sysfs is > getting beyond the original topic in this bugzilla entry. This is a more > general problem because there is no /sys/char directory. My current > opinion is that it would be nice to see these attributes somewhere, but > probably not worth the trouble. Until somebody asks for them, we're okay. However it shouldn't be very hard to write a function like blk_register_queue() that accepts a non-disk device as parent. (And likewise for blk_unregister_queue, of course.) Alan Stern -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug.