Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752590AbbF3TXY (ORCPT ); Tue, 30 Jun 2015 15:23:24 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:36124 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751945AbbF3TXQ (ORCPT ); Tue, 30 Jun 2015 15:23:16 -0400 Message-ID: <5592EC94.2080002@fb.com> Date: Tue, 30 Jun 2015 15:23:00 -0400 From: Josef Bacik User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Dave Jones , Chris Mason , , Linux Kernel Subject: Re: [4.1-rc7] btrfs related VM_BUG_ON in filemap.c References: <20150610134017.GA14803@codemonkey.org.uk> <55787743.4070308@fb.com> <20150616171443.GS6761@suse.cz> <55805A98.9020609@fb.com> <20150617133541.GA24428@codemonkey.org.uk> <20150630192006.GA14920@codemonkey.org.uk> In-Reply-To: <20150630192006.GA14920@codemonkey.org.uk> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-06-30_09:2015-06-29,2015-06-30,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3931 Lines: 71 On 06/30/2015 03:20 PM, Dave Jones wrote: > On Wed, Jun 17, 2015 at 09:35:41AM -0400, Dave Jones wrote: > > > page:ffffea00027cc640 count:4 mapcount:0 mapping:ffff8800af11d8a0 index:0x0 > > flags: 0x4000000000000846(error|referenced|active|private) > > page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) > > ------------[ cut here ]------------ > > kernel BUG at mm/filemap.c:745! > > invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > > CPU: 1 PID: 5931 Comm: trinity-c5 Not tainted 4.1.0-rc8-gelk-debug+ #2 > > task: ffff8800b9ec0000 ti: ffff8800843ec000 task.ti: ffff8800843ec000 > > RIP: 0010:[] [] unlock_page+0x7c/0x80 > > RSP: 0018:ffff8800843efa58 EFLAGS: 00010292 > > RAX: 0000000000000036 RBX: 0000000000001000 RCX: 0000000000000000 > > RDX: 0000000080000000 RSI: ffffffffb20c80c9 RDI: ffffffffb20c7ce4 > > RBP: ffff8800843efa58 R08: 0000000000000001 R09: 0000000000000d1d > > R10: 000000000000037c R11: 0000000000000001 R12: ffffea00027cc640 > > R13: 0000000000000000 R14: 0000000000000fff R15: 0000000000000000 > > FS: 00007fc9c42b5700(0000) GS:ffff8800bf700000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000000000000008 CR3: 0000000050978000 CR4: 00000000000007e0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > > Stack: > > ffff8800843efb68 ffffffffc02d06ec 0000000000000fff 0000100800000008 > > ffff8800af11d548 0000000000000000 ffff8800843efab8 0000000000000fff > > 0000000000000000 ffff88009f319000 ffff8800843efc08 ffff8800af11d728 > > Call Trace: > > [] __do_readpage+0x61c/0x7c0 [btrfs] > > [] ? lock_extent_bits+0x83/0x2e0 [btrfs] > > [] ? get_parent_ip+0x11/0x50 > > [] ? btrfs_real_readdir+0x5e0/0x5e0 [btrfs] > > [] ? btrfs_lookup_ordered_extent+0x9a/0xd0 [btrfs] > > [] __extent_read_full_page+0xc5/0xe0 [btrfs] > > [] ? btrfs_real_readdir+0x5e0/0x5e0 [btrfs] > > [] extent_read_full_page+0x37/0x60 [btrfs] > > [] btrfs_readpage+0x25/0x30 [btrfs] > > [] prepare_uptodate_page+0x4a/0x90 [btrfs] > > [] prepare_pages+0x101/0x190 [btrfs] > > [] __btrfs_buffered_write+0x1d3/0x650 [btrfs] > > [] btrfs_file_write_iter+0x463/0x570 [btrfs] > > [] ? bad_area+0x4a/0x60 > > [] __vfs_write+0xb1/0xf0 > > [] vfs_write+0xa9/0x1b0 > > [] SyS_pwrite64+0x72/0xb0 > > [] ? syscall_trace_enter_phase2+0x220/0x260 > > [] ? syscall_trace_leave+0x95/0x140 > > [] tracesys_phase2+0x84/0x89 > > Code: 10 48 d3 ee 48 8d 0c b6 48 89 c6 48 8d 3c ca 31 d2 e8 29 ca f4 ff 5d c3 0f 1f 80 00 00 00 00 48 c7 c6 c0 ed a2 b2 e8 f4 84 02 00 <0f> 0b 66 90 66 66 66 66 90 55 85 f6 48 89 e5 75 13 85 d2 74 3f > > RIP [] unlock_page+0x7c/0x80 > > Still occasionally bumping into this. > The 'count:4 mapcount:0' is constant in every instance I've seen > so far. Could that be a clue ? > > I've seen various page flags, but it's always !locked > > Ideas on additional debugging I could add ? > Huh I just noticed that PG_Error seems to be set, is that the same for every time? I wonder where that's getting set and why. I'll dig into the areas we set that and see if I can spot anything. Thanks, Josef -- 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/