From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: BUG: Null pointer dereference in fs/open.c Date: Thu, 26 Apr 2007 08:39:10 +0200 Message-ID: <20070426063910.GB3640@kernel.dk> References: <20070423215810.5a24ed9a.akpm@linux-foundation.org> <20070423221726.ccfa982c.akpm@linux-foundation.org> <20070425004816.bd0c240a.akpm@linux-foundation.org> <20070425160534.00c3a3d4.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from agminet01.oracle.com ([141.146.126.228]:28096 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933045AbXDZGka (ORCPT ); Thu, 26 Apr 2007 02:40:30 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: William Heimbigner Cc: Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , linux-ide@vger.kernel.org On Thu, Apr 26 2007, William Heimbigner wrote: > On Wed, 25 Apr 2007, Andrew Morton wrote: > >On Wed, 25 Apr 2007 22:53:00 +0000 (GMT) William Heimbigner > > wrote: > > > >>On Wed, 25 Apr 2007, Andrew Morton wrote: > >> > >>>OK. I am able to use the pktcdvd driver OK in mainline with a piix/sata > >>>drive. It could be that something is going wrong at the IDE level for > >>>you. > >>Perhaps; I'll try an external usb cd burner, and see where that goes. > >> > >>>Are you able to identify the most recent kernel which actually worked? > >>No, because I haven't set packet writing up in Linux before - however, I > >>do know > >>that I've successfully set up packet writing (using 2 of the 3 cd burners > >>I > >>have) in another operating system before. I'll try 2.6.18 and see if that > >>gets > >>me anywhere different, though. > > > >OK. > > > >A quick summary: mainline's pktcdvd isn't working for William using IDE. > >It is working for me using sata. > > > > > > >So what has happened here is that this code, in ide-cd.c's > >cdrom_decode_status() is now triggering: > > > > } else if (blk_pc_request(rq) || rq->cmd_type == REQ_TYPE_ATA_PC) { > > /* All other functions, except for READ. */ > > unsigned long flags; > > > > /* > > * if we have an error, pass back CHECK_CONDITION as the > > * scsi status byte > > */ > > if (blk_pc_request(rq) && !rq->errors) > > rq->errors = SAM_STAT_CHECK_CONDITION; > > > > > >I suspect this is a bug introduced by > >406c9b605cbc45151c03ac9a3f95e9acf050808c (in which case it'll be the third > >bug so far). > > > >Perhaps the IDE driver was previously not considering these requests to be > >of type blk_pc_request(), and after > >406c9b605cbc45151c03ac9a3f95e9acf050808c it _is_ treating them as > >blk_pc_request() and is incorrectly reporting an error. Or something like > >that. > > > >Guys: help! > > > A follow-up: after looking around a bit, I have managed to get packet > writing to work properly on /dev/hdc (before, it was reporting only 1.8 MB > available or so; this was a formatting issue). > I've also gotten the external cd-rw drive to work. However, I'm still at a > loss as to why /dev/hdd won't work. I tried formatting a dvd-rw for this > drive, however, it consistently gives me: > [27342.503933] drivers/ide/ide-cd.c:729: setting error to 2 > [27342.509251] [] show_trace_log_lvl+0x1a/0x30 > [27342.514411] [] show_trace+0x12/0x20 > [27342.518864] [] dump_stack+0x16/0x20 > [27342.523317] [] cdrom_decode_status+0x1f4/0x3b0 > [27342.528732] [] cdrom_newpc_intr+0x38/0x320 > [27342.533791] [] ide_intr+0x96/0x200 > [27342.538157] [] handle_IRQ_event+0x28/0x60 > [27342.543139] [] handle_edge_irq+0xa6/0x130 > [27342.548121] [] do_IRQ+0x49/0xa0 > [27342.552228] [] common_interrupt+0x2e/0x34 > [27342.557200] [] mwait_idle+0x12/0x20 > [27342.561653] [] cpu_idle+0x4a/0x80 > [27342.565934] [] rest_init+0x37/0x40 > [27342.570300] [] start_kernel+0x34b/0x420 > [27342.575109] [<00000000>] 0x0 > [27342.578089] ======================= > and doesn't work (the above output was generated by Andrew's patch to log > certain areas). > > # dvd+rw-format /dev/hdd -force > * BD/DVDRW/-RAM format utility by , version 7.0. > :-( failed to locate "Quick Format" descriptor. > * 4.7GB DVD-RW media in Sequential mode detected. > * formatting 0.0\:-[ READ TRACK INFORMATION failed with > SK=3h/ASC=11h/ACQ=05h]: Input/output error That's an uncorrectable read error. Is the media good? > I tried putting in a different dvd-rw, and this time I get: > # dvd+rw-format /dev/hdd -force > * BD/DVDRW/-RAM format utility by , version 7.0. > * 4.7GB DVD-RW media in Sequential mode detected. > * formatting 0.0|:-[ FORMAT UNIT failed with SK=5h/ASC=26h/ACQ=00h]: > Input/output error That's the drive complaining about an invalid bit being set in the command descriptor block. That's usually a bug in the issuer. -- Jens Axboe