From: Paul Mackerras Subject: Re: Crash in __brelse with recent kernels copying sparse file Date: Mon, 12 Dec 2011 17:04:52 +1100 Message-ID: <20111212060452.GA23428@drongo> References: <20111211232951.GA5380@bloggs.ozlabs.ibm.com> <20111212024359.GB12433@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Ted Ts'o Return-path: Received: from ozlabs.org ([203.10.76.45]:47469 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751486Ab1LLGFA (ORCPT ); Mon, 12 Dec 2011 01:05:00 -0500 Content-Disposition: inline In-Reply-To: <20111212024359.GB12433@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Dec 11, 2011 at 09:43:59PM -0500, Ted Ts'o wrote: > Hmm, can you try this patch, and see if it triggers? > > I've removed all of the static declarations so that the stack trace > will hopefully be more accurate. (I don't know if you have a reliable > way to map hex addresses to line numbers on PowerPC, but it's > critically important to do that given the huge number of static > functions that generally get inlined, making the stack trace hard to > decipher if you can't get the line numbers.) Yes, it triggers: EXT4-fs (sda8): ext4_ext_find_extent: inode 264547, depth 257 > path->p_depth 1 ------------[ cut here ]------------ kernel BUG at /home/paulus/kernel/kvm-merge/fs/ext4/extents.c:645! cpu 0x1: Vector: 700 (Program Check) at [c000001bc8772dd0] pc: c0000000002df3d4: .ext4_ext_find_extent+0x3d4/0x3e0 lr: c0000000002df3d0: .ext4_ext_find_extent+0x3d0/0x3e0 sp: c000001bc8773050 msr: 9000000000029032 current = 0xc000001bcc4b3b10 paca = 0xc00000000ffe0380 pid = 4211, comm = flush-8:0 kernel BUG at /home/paulus/kernel/kvm-merge/fs/ext4/extents.c:645! enter ? for help [c000001bc8773130] c0000000002e0324 .ext4_ext_create_new_leaf+0x144/0x230 [c000001bc87731e0] c0000000002e16ec .ext4_ext_insert_extent+0x15c/0x5a0 [c000001bc87732b0] c0000000002e5b78 .ext4_ext_map_blocks+0x5b8/0xea0 [c000001bc8773420] c0000000002b2974 .ext4_map_blocks+0x224/0x310 [c000001bc87734d0] c0000000002b7f2c .mpage_da_map_and_submit+0xbc/0x490 [c000001bc87735a0] c0000000002b8688 .write_cache_pages_da+0x2c8/0x430 [c000001bc8773720] c0000000002b8b28 .ext4_da_writepages+0x338/0x670 [c000001bc87738d0] c000000000157280 .do_writepages+0x40/0x90 [c000001bc8773940] c0000000001ea830 .writeback_single_inode+0xe0/0x530 [c000001bc8773a00] c0000000001eb680 .writeback_sb_inodes+0x210/0x300 [c000001bc8773b20] c0000000001ebc84 .__writeback_inodes_wb+0xd4/0x140 [c000001bc8773be0] c0000000001ebfec .wb_writeback+0x2fc/0x3e0 [c000001bc8773ce0] c0000000001ed55c .wb_do_writeback+0xdc/0x300 [c000001bc8773df0] c0000000001ed848 .bdi_writeback_thread+0xc8/0x340 [c000001bc8773ed0] c0000000000c5494 .kthread+0xb4/0xc0 [c000001bc8773f90] c000000000021f48 .kernel_thread+0x54/0x70 I'll try to dig out some line numbers for you. Paul.