From owner-freebsd-hackers@freebsd.org Wed Jul 6 18:21:22 2016 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 21921B758E1; Wed, 6 Jul 2016 18:21:22 +0000 (UTC) (envelope-from dcrosstech@gmail.com) Received: from mail-yw0-x22b.google.com (mail-yw0-x22b.google.com [IPv6:2607:f8b0:4002:c05::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D0B001E4D; Wed, 6 Jul 2016 18:21:21 +0000 (UTC) (envelope-from dcrosstech@gmail.com) Received: by mail-yw0-x22b.google.com with SMTP id i12so93695696ywa.1; Wed, 06 Jul 2016 11:21:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=ikdf9Rq5KobUSGbfr4AZiaSUJp18yozYm7mOPTwnuUY=; b=DEqHrWCXbjcIYFI1pGyosuciVRwkrQH/ArI4mdJjdasWdIr0xdtZkpcO2QXD+o0gnS WJAnoNND6plO8Njl2BVvxNjasYKWt986YwtpFF6GCHvzNSwWo1zqeW7EzQcnd6qmMHq9 YXG7IKYGyh1g0GtgfahKUwnUzPX5c6T7dI9+E23Og7/cj3VnXCtrGc8Q3P0UHcrq/Y5T kFAO0StGgoskh2HGWPezYJYTCCcwoYdraqtEoCWw60/ej6cGN9J7ptl+44SP0gP4Qsxk AH/WWryVPoJhrweV9ctEkk7Rr8hsUyOB3yRYwCLAlSarduyTrsm0BuUYF5k+ra111xp1 Yw5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=ikdf9Rq5KobUSGbfr4AZiaSUJp18yozYm7mOPTwnuUY=; b=Lk7j6Afh5UxY+3bMfhdFN1pnRP12mP0tDr46r4X182IMQQcmzIrGXERSXOOprYAtnn omdBR/azu5KChkAoKsJKhJFg0zjVYCMxeiW7QQ4Ht2i9DVNAXDAVwpgjcxf2H0NuXwff 8Dplat+eaD4PJn2Fh4aca+X8oGDVmj8BHKaa7U/jXZ0PnE9Db8hFFazTDJ9g6kBq1Ocl lkTkOdE4kPzkqYj5dHZCmi8NECuanjCTVqRO0VVJpmV0189E5/d1/iw70FeOG9ijh40S 444rcMhrfz+p9V0amPdNyMdC5qF55zYb8VPczP++N8L2ZzQF1fuso8dgMeHG+29QlhYS 3Opw== X-Gm-Message-State: ALyK8tIr8B4SmAoSIsmDAFIZfEaoMsXeq1XVYe3MzxjanVoR6pZWrN0u6Q8gz3QCxRffJO4rwwMiHuCp5JuTQQ== X-Received: by 10.129.102.195 with SMTP id a186mr15678812ywc.76.1467829281073; Wed, 06 Jul 2016 11:21:21 -0700 (PDT) MIME-Version: 1.0 Received: by 10.37.212.66 with HTTP; Wed, 6 Jul 2016 11:21:20 -0700 (PDT) In-Reply-To: <20160706173758.GF38613@kib.kiev.ua> References: <20160706151822.GC38613@kib.kiev.ua> <20160706173758.GF38613@kib.kiev.ua> From: David Cross Date: Wed, 6 Jul 2016 14:21:20 -0400 Message-ID: Subject: Re: Reproducable panic in FFS with softupdates and no journaling (10.3-RELEASE-pLATEST) To: Konstantin Belousov Cc: freebsd-stable@freebsd.org, freebsd-hackers@freebsd.org X-Mailman-Approved-At: Wed, 06 Jul 2016 18:22:55 +0000 Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.22 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Jul 2016 18:21:22 -0000 (kgdb) up 5 #5 0xffffffff804aafa1 in brelse (bp=0xfffffe00f77457d0) at buf.h:428 428 (*bioops.io_deallocate)(bp); Current language: auto; currently minimal (kgdb) p/x *(struct buf *)0xfffffe00f77457d0 $1 = {b_bufobj = 0xfffff80002e88480, b_bcount = 0x4000, b_caller1 = 0x0, b_data = 0xfffffe00f857b000, b_error = 0x0, b_iocmd = 0x0, b_ioflags = 0x0, b_iooffset = 0x0, b_resid = 0x0, b_iodone = 0x0, b_blkno = 0x115d6400, b_offset = 0x0, b_bobufs = {tqe_next = 0x0, tqe_prev = 0xfffff80002e884d0}, b_vflags = 0x0, b_freelist = {tqe_next = 0xfffffe00f7745a28, tqe_prev = 0xffffffff80c2afc0}, b_qindex = 0x0, b_flags = 0x20402800, b_xflags = 0x2, b_lock = {lock_object = {lo_name = 0xffffffff8075030b, lo_flags = 0x6730000, lo_data = 0x0, lo_witness = 0xfffffe0000602f00}, lk_lock = 0xfffff800022e8000, lk_exslpfail = 0x0, lk_timo = 0x0, lk_pri = 0x60}, b_bufsize = 0x4000, b_runningbufspace = 0x0, b_kvabase = 0xfffffe00f857b000, b_kvaalloc = 0x0, b_kvasize = 0x4000, b_lblkno = 0x0, b_vp = 0xfffff80002e883b0, b_dirtyoff = 0x0, b_dirtyend = 0x0, b_rcred = 0x0, b_wcred = 0x0, b_saveaddr = 0x0, b_pager = { pg_reqpage = 0x0}, b_cluster = {cluster_head = {tqh_first = 0x0, tqh_last = 0x0}, cluster_entry = {tqe_next = 0x0, tqe_prev = 0x0}}, b_pages = {0xfffff800b99b30b0, 0xfffff800b99b3118, 0xfffff800b99b3180, 0xfffff800b99b31e8, 0x0 }, b_npages = 0x4, b_dep = { lh_first = 0xfffff800023d8c00}, b_fsprivate1 = 0x0, b_fsprivate2 = 0x0, b_fsprivate3 = 0x0, b_pin_count = 0x0} This is the freshly allocated buf that causes the panic; is this what is needed? I "know" which vnode will cause the panic on vnlru cleanup, but I don't know how to walk the memory list without a 'hook'.. as in, i can setup the kernel in a state that I know will panic when the vnode is cleaned up, I can force a panic 'early' (kill -9 1), and then I could get that vnode.. if I could get the vnode list to walk. On Wed, Jul 6, 2016 at 1:37 PM, Konstantin Belousov wrote: > On Wed, Jul 06, 2016 at 12:02:00PM -0400, David Cross wrote: > > Oh, whoops; how do I printout the buffer? > > In kgdb, p/x *(struct buf *)address >