Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759373AbXINLGX (ORCPT ); Fri, 14 Sep 2007 07:06:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754371AbXINLGP (ORCPT ); Fri, 14 Sep 2007 07:06:15 -0400 Received: from brick.kernel.dk ([87.55.233.238]:12560 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754352AbXINLGO (ORCPT ); Fri, 14 Sep 2007 07:06:14 -0400 Date: Fri, 14 Sep 2007 13:06:06 +0200 From: Jens Axboe To: Laurent Riffard Cc: Andrew Morton , linux-kernel@vger.kernel.org, Peter Osterlund Subject: Re: 2.6.23-rc4-mm1: git-block.patch broke pktcdvd Message-ID: <20070914110606.GJ25592@kernel.dk> References: <20070831215822.26e1432b.akpm@linux-foundation.org> <46E5A6D1.3050704@free.fr> <46E9BEB1.3060504@free.fr> <20070914093358.GB25592@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20070914093358.GB25592@kernel.dk> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5758 Lines: 107 On Fri, Sep 14 2007, Jens Axboe wrote: > On Fri, Sep 14 2007, Laurent Riffard wrote: > > Le 10.09.2007 22:19, Laurent Riffard a ?crit : > > > Le 01.09.2007 06:58, Andrew Morton a ?crit : > > >> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.23-rc4/2.6.23-rc4-mm1/ > > > [...] > > > > > > Jens, > > > > > > git-block.patch broke pktcdvd, I've got an Oops while syncing: > > > > > >> [ 713.014888] pktcdvd: Fixed packets, 16 blocks, Mode-1 disc > > >> [ 713.021844] pktcdvd: write speed 2770kB/s > > >> [ 718.401761] pktcdvd: 4595774kB available on disc > > >> [ 721.175644] UDF-fs INFO UDF 0.9.8.1 (2004/29/09) Mounting volume 'LinuxUDF', timestamp 2006/10/08 21:17 (1078) > > >> [ 721.213784] mount used greatest stack depth: 460 bytes left > > >> [ 752.634402] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000 > > >> [ 752.635711] printing eip: c017b69e *pde = 00000000 > > >> [ 752.636983] Oops: 0002 [#1] PREEMPT > > >> [ 752.638240] last sysfs file: /devices/pci0000:00/0000:00:0d.0/modalias > > >> [ 752.639477] Modules linked in: udf binfmt_misc pktcdvd radeon drm lp nls_iso8859_1 nls_cp850 vfat fat reiser4 lzo_decompress lzo_compress eeprom w83781d hwmon_vid snd_ens1371 gameport snd_ac97_codec ac97_bus snd_pcm_oss snd_mixer_oss snd_pcm sg firewire_ohci firewire_core sr_mod cdrom crc_itu_t snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device snd 8250_pnp i2c_viapro via_agp floppy ohci1394 soundcore 8250 serial_core ata_generic uhci_hcd agpgart ne2k_pci 8390 ieee1394 snd_page_alloc rtc pcspkr via686a usbcore parport_pc parport evdev reiserfs sd_mod pata_via libata scsi_mod dm_mirror dm_mod > > >> [ 752.645759] > > >> [ 752.646990] Pid: 3403, comm: pktcdvd0 Not tainted (2.6.23-rc4-mm1 #50) > > >> [ 752.648256] EIP: 0060:[__bio_add_page+212/355] EFLAGS: 00010246 CPU: 0 > > >> [ 752.649515] EIP is at __bio_add_page+0xd4/0x163 > > >> [ 752.650750] EAX: 00000000 EBX: 00000000 ECX: c26ca400 EDX: 00000000 > > >> [ 752.651984] ESI: cba3cf48 EDI: c1174be0 EBP: cb01cef4 ESP: cb01cee4 > > >> [ 752.653219] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 > > >> [ 752.654446] Process pktcdvd0 (pid: 3403, ti=cb01c000 task=c1b9cdb0 task.ti=cb01c000) > > >> [ 752.654526] Stack: c26ca400 cba3cf48 c1174be0 00000001 cb01cf10 c017b763 00000800 00000800 > > >> [ 752.655908] 00000040 cba3cf48 cb06e120 cb01cfd0 e1d94044 00000800 00000004 cb09b8a0 > > >> [ 752.657297] c1853ce0 00000000 00000800 00000001 00000000 00000000 00000000 00000000 > > >> [ 752.658695] Call Trace: > > >> [ 752.661126] [show_trace_log_lvl+26/47] show_trace_log_lvl+0x1a/0x2f > > >> [ 752.662383] [show_stack_log_lvl+155/163] show_stack_log_lvl+0x9b/0xa3 > > >> [ 752.663626] [show_registers+160/482] show_registers+0xa0/0x1e2 > > >> [ 752.664868] [die+261/567] die+0x105/0x237 > > >> [ 752.666072] [do_page_fault+1127/1349] do_page_fault+0x467/0x545 > > >> [ 752.667274] [error_code+106/112] error_code+0x6a/0x70 > > >> [ 752.668477] [bio_add_page+54/61] bio_add_page+0x36/0x3d > > >> [ 752.669669] [] kcdrwd+0x5a5/0x9ba [pktcdvd] > > >> [ 752.670856] [kthread+57/97] kthread+0x39/0x61 > > >> [ 752.672024] [kernel_thread_helper+7/16] kernel_thread_helper+0x7/0x10 > > >> [ 752.673197] ======================= > > >> [ 752.674336] Code: ba 01 00 00 00 8b 4d f0 8b 46 18 66 3b 81 50 01 00 00 73 da 66 8b 46 1a 66 3b 81 52 01 00 00 73 cd 0f > > >> b7 46 14 6b d8 0c 03 5e 2c <89> 3b 8b 45 08 89 43 04 8b 4d 0c 89 4b 08 8b 45 f0 8b 78 68 85 > > >> [ 752.677879] EIP: [__bio_add_page+212/355] __bio_add_page+0xd4/0x163 SS:ESP 0068:cb01cee4 > > > > I dig through git-block.patch and the culprit seems to be commit > > c94f1c4ac87862675c8d70941973bc3a69aff5d8 "bio: use memset() in > > bio_init()". > > > > Maybe the real bug is a bad bio initialization in pktcdvd driver, > > which is revealed by this commit ? > > At least pktcdvd doesn't expect bio->bi_io_vec[] to be cleared, that's > why it's oopsing now. I'll revert this bit for now, thanks for the > report. Rethinking this, I think bio_init() is doing the right thing, only pktcdvd seems to rely on it preserving some members. So I'd rather fixup pktcdvd instead. Does this work for you? diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index fadbfd8..98343a1 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -1142,16 +1142,20 @@ static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt) * Schedule reads for missing parts of the packet. */ for (f = 0; f < pkt->frames; f++) { + struct bio_vec *vec; + int p, offset; if (written[f]) continue; bio = pkt->r_bios[f]; + vec = bio->bi_io_vec; bio_init(bio); bio->bi_max_vecs = 1; bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9); bio->bi_bdev = pd->bdev; bio->bi_end_io = pkt_end_io_read; bio->bi_private = pkt; + bio->bi_io_vec = vec; p = (f * CD_FRAMESIZE) / PAGE_SIZE; offset = (f * CD_FRAMESIZE) % PAGE_SIZE; @@ -1448,6 +1452,7 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt) pkt->w_bio->bi_bdev = pd->bdev; pkt->w_bio->bi_end_io = pkt_end_io_packet_write; pkt->w_bio->bi_private = pkt; + pkt->w_bio->bi_io_vec = bvec; for (f = 0; f < pkt->frames; f++) if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset)) BUG(); -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/