From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [Bugme-new] [Bug 7864] New: A MTIOCTOP/MTWEOF within the early warning will cause the file number to be incorrect Date: Wed, 24 Jan 2007 20:48:04 -0800 Message-ID: <20070124204804.77486468.akpm@osdl.org> References: <200701222107.l0ML7KPn010266@fire-2.osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.osdl.org ([65.172.181.24]:46624 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752115AbXAYEsP (ORCPT ); Wed, 24 Jan 2007 23:48:15 -0500 In-Reply-To: <200701222107.l0ML7KPn010266@fire-2.osdl.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: ce_reisinger@yahoo.com Cc: "bugme-daemon@kernel-bugs.osdl.org" , linux-scsi@vger.kernel.org, Kai Makisara On Mon, 22 Jan 2007 13:07:20 -0800 bugme-daemon@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=7864 > > Summary: A MTIOCTOP/MTWEOF within the early warning will cause > the file number to be incorrect > Kernel Version: 2.6.19.2 > Status: NEW > Severity: low > Owner: io_scsi@kernel-bugs.osdl.org > Submitter: ce_reisinger@yahoo.com > > > Write records to a SCSI tape until a write fails with a ENOSPC (you have reached > early warning. > Now perform a: > struct mtget before, after; > ioctl(fd, MTIOCGET, &before); > struct mtop mtop = { MTWEOF, 1 }; > ioctl(fd, MTIOCTOP, &mtop); > ioctl(fd, MTIOCGET, &after); > > Check the value of mt_fileno in the before and after structures. Notice the > after is 2 greater then the before. > > The problem appears to be in the block of code starting at line 2817 in st.c. > This block is entered because the drive did return a CHECK CONDITION with NO > SENSE and the SENSE_EOM bit set. At lines 2824/5 the fileno is incremented. But > it has already been increased by the number of filemarks requested by the > MTIOCTOP. I believe that the residue count in the sense data should be > subtracted from fileno, not a increment as is done. > Thanks. Could you please send us a tested patch to fix these things, as per http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt ?