From owner-freebsd-hackers@freebsd.org Tue Apr 18 17:19:31 2017 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 931C2D44E3E for ; Tue, 18 Apr 2017 17:19:31 +0000 (UTC) (envelope-from wojtek@puchar.net) Received: from puchar.net (puchar.net [194.1.144.90]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "puchar.net", Issuer "puchar.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 111DF77B for ; Tue, 18 Apr 2017 17:19:30 +0000 (UTC) (envelope-from wojtek@puchar.net) Received: Received: from 127.0.0.1 (localhost [127.0.0.1]) by puchar.net (8.15.2/8.14.9) with ESMTPS id v3IGnenS032517 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 18 Apr 2017 18:49:41 +0200 (CEST) (envelope-from wojtek@puchar.net) Received: from laptop.wojtek.intra (localhost [127.0.0.1]) by laptop.wojtek.intra (8.15.2/8.14.9) with ESMTP id v3IGnaZG014435 for ; Tue, 18 Apr 2017 18:49:36 +0200 (CEST) (envelope-from wojtek@puchar.net) Received: from localhost (wojtek@localhost) by laptop.wojtek.intra (8.15.2/8.14.9/Submit) with ESMTP id v3IGnU64014432 for ; Tue, 18 Apr 2017 18:49:31 +0200 (CEST) (envelope-from wojtek@puchar.net) X-Authentication-Warning: laptop.wojtek.intra: wojtek owned process doing -bs Date: Tue, 18 Apr 2017 18:49:30 +0200 (CEST) From: Wojciech Puchar X-X-Sender: wojtek@laptop.wojtek.intra To: freebsd-hackers@freebsd.org Subject: lock order reversal dirhash/bufwait Message-ID: User-Agent: Alpine 2.20 (BSF 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Apr 2017 17:19:31 -0000 i'm getting this with latest 10-stable with witness etc. enabled. how to fix it? UFS options are options FFS # Berkeley Fast Filesystem options SOFTUPDATES # Enable FFS soft updates support options UFS_DIRHASH # Improve performance on big lock order reversal: 1st 0xfffffe0060aa58f8 bufwait (bufwait) @ kern/vfs_bio.c:3130 2nd 0xfffff800048db800 dirhash (dirhash) @ ufs/ufs/ufs_dirhash.c:280 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2e/frame 0xfffffe0072edcf90 kdb_backtrace() at kdb_backtrace+0x58/frame 0xfffffe0072edd040 _witness_debugger() at _witness_debugger+0x34/frame 0xfffffe0072edd060 witness_checkorder() at witness_checkorder+0xfda/frame 0xfffffe0072edd280 _sx_xlock() at _sx_xlock+0x12f/frame 0xfffffe0072edd2d0 ufsdirhash_acquire() at ufsdirhash_acquire+0x4a/frame 0xfffffe0072edd300 ufsdirhash_add() at ufsdirhash_add+0x1c/frame 0xfffffe0072edd340 ufs_direnter() at ufs_direnter+0xc4a/frame 0xfffffe0072edd490 ufs_makeinode() at ufs_makeinode+0x58d/frame 0xfffffe0072edd620 ufs_create() at ufs_create+0x51/frame 0xfffffe0072edd650 VOP_CREATE_APV() at VOP_CREATE_APV+0x1c4/frame 0xfffffe0072edd6a0 VOP_CREATE() at VOP_CREATE+0x51/frame 0xfffffe0072edd700 vn_open_cred() at vn_open_cred+0x2b4/frame 0xfffffe0072edd820 vn_open() at vn_open+0x47/frame 0xfffffe0072edd860 kern_openat() at kern_openat+0x1f5/frame 0xfffffe0072edda20 kern_open() at kern_open+0x37/frame 0xfffffe0072edda50 sys_open() at sys_open+0x31/frame 0xfffffe0072edda70 syscallenter() at syscallenter+0x456/frame 0xfffffe0072eddab0 amd64_syscall() at amd64_syscall+0x57/frame 0xfffffe0072eddbb0 Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe0072eddbb0 --- syscall (5, FreeBSD ELF64, sys_open), rip = 0x800b71a3a, rsp = 0x7fffffffe578, rbp = 0x7fffffffe5a0 ---