From owner-svn-src-head@freebsd.org Mon Aug 26 20:15:12 2019 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9ECEFE40BF; Mon, 26 Aug 2019 20:15:12 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from smtp-out-so.shaw.ca (smtp-out-so.shaw.ca [64.59.136.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 46HNXb2wGtz3N7q; Mon, 26 Aug 2019 20:15:11 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from spqr.komquats.com ([70.67.125.17]) by shaw.ca with ESMTPA id 2LOMiqX2fSrVc2LONimzLk; Mon, 26 Aug 2019 14:15:08 -0600 X-Authority-Analysis: v=2.3 cv=L5ZjvNb8 c=1 sm=1 tr=0 a=VFtTW3WuZNDh6VkGe7fA3g==:117 a=VFtTW3WuZNDh6VkGe7fA3g==:17 a=kj9zAlcOel0A:10 a=FmdZ9Uzk2mMA:10 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=u4J8QU_s_-lIpTMvNuEA:9 a=7rGe7H_wMalzTzRd:21 a=rQ4BupQ3IxZE0W-Y:21 a=P72zRhDHRApVOsr8:21 a=CjuIK1q_8ugA:10 a=Ia-lj3WSrqcvXOmTRaiG:22 a=IjZwj45LgO3ly-622nXo:22 Received: from slippy.cwsent.com (slippy8 [10.2.2.6]) by spqr.komquats.com (Postfix) with ESMTPS id E0FBF3FB; Mon, 26 Aug 2019 13:15:05 -0700 (PDT) Received: from slippy.cwsent.com (localhost [127.0.0.1]) by slippy.cwsent.com (8.15.2/8.15.2) with ESMTP id x7QKF5WV050008; Mon, 26 Aug 2019 13:15:05 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Received: from slippy (cy@localhost) by slippy.cwsent.com (8.15.2/8.15.2/Submit) with ESMTP id x7QKF5Q1049991; Mon, 26 Aug 2019 13:15:05 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <201908262015.x7QKF5Q1049991@slippy.cwsent.com> X-Authentication-Warning: slippy.cwsent.com: cy owned process doing -bs X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7.1 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: Cy Schubert cc: Mateusz Guzik , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r351472 - head/sys/fs/nullfs In-reply-to: References: <201908250513.x7P5DFFx017824@repo.freebsd.org> <6C6BF3A4-DC07-4D9A-9A5F-FA075BF535A8@cschubert.com> <201908261411.x7QEBMWi075354@slippy.cwsent.com> Comments: In-reply-to Cy Schubert message dated "Mon, 26 Aug 2019 11:56:43 -0700." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 26 Aug 2019 13:15:05 -0700 X-CMAE-Envelope: MS4wfD9c+PFg6rxoqmm9IKr3DJ0+D6RN4Yf4F3QPn7Z8s8yCOX2iYMXPyBoWjMEOETSrCUi90CB7fUg/D+y8i9fs9Av6VGMY7Jx8jEo981MQQIN4PauMGqcq eDTy8lt49fiJJVyyHwKUAXCnxGm1xLCkMNqjvqpJ+5U2QZLC9Z3yDku7LSIoL3KqMhN+/AR0heJqIr85El128R9HGFV1/UMLJdOKOCLYTiRdLQqkT7HMF/pO mhD0TBqxjyGgyB4S5ZqZOcCtzXQ7T/kAtG64yD6fHORbp7nm6NztzrCGkOtuXLew X-Rspamd-Queue-Id: 46HNXb2wGtz3N7q X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=none; spf=none (mx1.freebsd.org: domain of cy.schubert@cschubert.com has no SPF policy when checking 64.59.136.137) smtp.mailfrom=cy.schubert@cschubert.com X-Spamd-Result: default: False [-4.89 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_COUNT_FIVE(0.00)[5]; HAS_REPLYTO(0.00)[Cy.Schubert@cschubert.com]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; RCPT_COUNT_FIVE(0.00)[5]; REPLYTO_EQ_FROM(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_SHORT(-0.96)[-0.965,0]; RCVD_IN_DNSWL_NONE(0.00)[137.136.59.64.list.dnswl.org : 127.0.5.0]; R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:6327, ipnet:64.59.128.0/20, country:CA]; RCVD_TLS_LAST(0.00)[]; IP_SCORE(-2.33)[ip: (-5.95), ipnet: 64.59.128.0/20(-3.15), asn: 6327(-2.45), country: CA(-0.09)]; RECEIVED_SPAMHAUS_PBL(0.00)[17.125.67.70.khpj7ygk5idzvmvt5x4ziurxhy.zen.dq.spamhaus.net : 127.0.0.11] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Aug 2019 20:15:12 -0000 In message , Cy Schubert wr ites: > On August 26, 2019 8:40:50 AM PDT, Cy Schubert wr > ote: > >On August 26, 2019 7:11:22 AM PDT, Cy Schubert > > wrote: > >>In message <6C6BF3A4-DC07-4D9A-9A5F-FA075BF535A8@cschubert.com>, Cy > >>Schubert wr > >>ites: > >>> On August 24, 2019 10:13:15 PM PDT, Mateusz Guzik > >>wrote: > >>> >Author: mjg > >>> >Date: Sun Aug 25 05:13:15 2019 > >>> >New Revision: 351472 > >>> >URL: https://svnweb.freebsd.org/changeset/base/351472 > >>> > > >>> >Log: > >>> > nullfs: reduce areas protected by vnode interlock > >>> > > >>> >Some places only take the interlock to hold the vnode, which was a > >>> >requiremnt > >>> >before they started being manipulated with atomics. Use the newly > >>> >introduced > >>> > vholdnz to bump the count. > >>> > > >>> > Reviewed by: kib > >>> > Tested by: pho > >>> > Sponsored by: The FreeBSD Foundation > >>> > Differential Revision: https://reviews.freebsd.org/D21358 > >>> > > >>> >Modified: > >>> > head/sys/fs/nullfs/null_vnops.c > >>> > > >>> >Modified: head/sys/fs/nullfs/null_vnops.c > >>> > >>>========================================================================== > == > >>> == > >>> >--- head/sys/fs/nullfs/null_vnops.c Sun Aug 25 05:11:43 > >2019 (r35147 > >>> 1) > >>> >+++ head/sys/fs/nullfs/null_vnops.c Sun Aug 25 05:13:15 > >2019 (r35147 > >>> 2) > >>> >@@ -668,7 +668,7 @@ null_lock(struct vop_lock1_args *ap) > >>> > * We prevent it from being recycled by holding the vno > de > >>> > * here. > >>> > */ > >>> >- vholdl(lvp); > >>> >+ vholdnz(lvp); > >>> > error = VOP_LOCK(lvp, flags); > >>> > > >>> > /* > >>> >@@ -710,31 +710,16 @@ static int > >>> > null_unlock(struct vop_unlock_args *ap) > >>> > { > >>> > struct vnode *vp = ap->a_vp; > >>> >- int flags = ap->a_flags; > >>> >- int mtxlkflag = 0; > >>> > struct null_node *nn; > >>> > struct vnode *lvp; > >>> > int error; > >>> > > >>> >- if ((flags & LK_INTERLOCK) != 0) > >>> >- mtxlkflag = 1; > >>> >- else if (mtx_owned(VI_MTX(vp)) == 0) { > >>> >- VI_LOCK(vp); > >>> >- mtxlkflag = 2; > >>> >- } > >>> > nn = VTONULL(vp); > >>> > if (nn != NULL && (lvp = NULLVPTOLOWERVP(vp)) != NULL) { > >>> >- VI_LOCK_FLAGS(lvp, MTX_DUPOK); > >>> >- flags |= LK_INTERLOCK; > >>> >- vholdl(lvp); > >>> >- VI_UNLOCK(vp); > >>> >- error = VOP_UNLOCK(lvp, flags); > >>> >+ vholdnz(lvp); > >>> >+ error = VOP_UNLOCK(lvp, 0); > >>> > vdrop(lvp); > >>> >- if (mtxlkflag == 0) > >>> >- VI_LOCK(vp); > >>> > } else { > >>> >- if (mtxlkflag == 2) > >>> >- VI_UNLOCK(vp); > >>> > error = vop_stdunlock(ap); > >>> > } > >>> > > >>> >@@ -845,10 +830,8 @@ null_getwritemount(struct > >>vop_getwritemount_args > >>> >*ap) > >>> > VI_LOCK(vp); > >>> > xp = VTONULL(vp); > >>> > if (xp && (lowervp = xp->null_lowervp)) { > >>> >- VI_LOCK_FLAGS(lowervp, MTX_DUPOK); > >>> >+ vholdnz(lowervp); > >>> > VI_UNLOCK(vp); > >>> >- vholdl(lowervp); > >>> >- VI_UNLOCK(lowervp); > >>> > VOP_GETWRITEMOUNT(lowervp, ap->a_mpp); > >>> > vdrop(lowervp); > >>> > } else { > >>> > >>> Hi mjg@, > >>> > >>> This causes trap 12 a few seconds after mountlate during boot. > >>Reverting this > >>> commit allowed it to boot. > >>> > >>> Sorry for no backtrace. I managed to > >>> revert and test just prior to rushing out to catch the bus, with no > >>time to > >>> craft a proper email. I'll post the backtrace when I arrive at work. > >> > >>Hi mjg@, > >> > >>The gory details below. Don't be fooled by the panic when yppasswd is > >>started. I was able to reproduce this panic in single user by simply > >>mounting and using a nullfs. > >> > >>kernel trap 12 with interrupts disabled > >> > >> > >>Fatal trap 12: page fault while in kernel mode > >>cpuid = 0; apic id = 00 > >>fault virtual address = 0xc > >>fault code = supervisor read data, page not present > >>instruction pointer = 0x20:0xffffffff806f0633 > >>stack pointer = 0x28:0xfffffe004b3fa7c0 > >>frame pointer = 0x28:0xfffffe004b3fa7e0 > >>code segment = base 0x0, limit 0xfffff, type 0x1b > >> = DPL 0, pres 1, long 1, def32 0, gran 1 > >>processor eflags = resume, IOPL = 0 > >>current process = 26 (syncer) > >>trap number = 12 > >>panic: page fault > >>cpuid = 0 > >>time = 1566821203 > >>KDB: stack backtrace: > >>db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > >>0xfffffe004b3fa470 > >>vpanic() at vpanic+0x19d/frame 0xfffffe004b3fa4c0 > >>panic() at panic+0x43/frame 0xfffffe004b3fa520 > >>trap_fatal() at trap_fatal+0x39c/frame 0xfffffe004b3fa580 > >>trap_pfault() at trap_pfault+0x49/frame 0xfffffe004b3fa5e0 > >>trap() at trap+0x29d/frame 0xfffffe004b3fa6f0 > >>calltrap() at calltrap+0x8/frame 0xfffffe004b3fa6f0 > >>--- trap 0xc, rip = 0xffffffff806f0633, rsp = 0xfffffe004b3fa7c0, rbp > >= > >>0xfffffe004b3fa7e0 --- > >>propagate_priority() at propagate_priority+0x153/frame > >>0xfffffe004b3fa7e0 > >>turnstile_wait() at turnstile_wait+0x32b/frame 0xfffffe004b3fa830 > >>__mtx_lock_sleep() at __mtx_lock_sleep+0x191/frame 0xfffffe004b3fa8c0 > >>mnt_vnode_next_active() at mnt_vnode_next_active+0x2cb/frame > >>0xfffffe004b3fa920 > >>vfs_msync() at vfs_msync+0x266/frame 0xfffffe004b3fa980 > >>sync_fsync() at sync_fsync+0xe6/frame 0xfffffe004b3fa9c0 > >>VOP_FSYNC_APV() at VOP_FSYNC_APV+0x56/frame 0xfffffe004b3fa9e0 > >>sched_sync() at sched_sync+0x379/frame 0xfffffe004b3faa70 > >>fork_exit() at fork_exit+0x83/frame 0xfffffe004b3faab0 > >>fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe004b3faab0 > >>--- trap 0, rip = 0, rsp = 0, rbp = 0 --- > >>Uptime: 3m25s > >>Dumping 921 out of 7974 > >>MB:..2%..11%..21%..32%..42%..51%..61%..72%..82%..91% > >> > >>__curthread () at /opt/src/svn-current/sys/amd64/include/pcpu.h:246 > >>246 __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" > >>(OFFSETOF_CURTHREAD)); > >>(kgdb) #0 __curthread () at > >>/opt/src/svn-current/sys/amd64/include/pcpu.h:246 > >>#1 doadump (textdump=1) at > >>/opt/src/svn-current/sys/kern/kern_shutdown.c:392 > >>#2 0xffffffff8068aead in kern_reboot (howto=260) > >> at /opt/src/svn-current/sys/kern/kern_shutdown.c:479 > >>#3 0xffffffff8068b369 in vpanic (fmt=, ap= >>out>) > >> at /opt/src/svn-current/sys/kern/kern_shutdown.c:905 > >>#4 0xffffffff8068b163 in panic (fmt=) > >> at /opt/src/svn-current/sys/kern/kern_shutdown.c:832 > >>#5 0xffffffff80a11c2c in trap_fatal (frame=0xfffffe004b3fa700, > >eva=12) > >> at /opt/src/svn-current/sys/amd64/amd64/trap.c:943 > >>#6 0xffffffff80a11c79 in trap_pfault (frame=0xfffffe004b3fa700, > >>usermode=0) > >> at /opt/src/svn-current/sys/amd64/amd64/trap.c:767 > >>#7 0xffffffff80a1126d in trap (frame=0xfffffe004b3fa700) > >> at /opt/src/svn-current/sys/amd64/amd64/trap.c:443 > >>#8 > >>#9 propagate_priority (td=0xfffff8003e43b000) > >> at /opt/src/svn-current/sys/kern/subr_turnstile.c:279 > >>#10 0xffffffff806f13db in turnstile_wait (ts=0xfffff8000258a780, > >> owner=, queue=-512) > >> at /opt/src/svn-current/sys/kern/subr_turnstile.c:785 > >>#11 0xffffffff80669271 in __mtx_lock_sleep (c=0xfffff80132e4ebf0, > >> v=) at > >/opt/src/svn-current/sys/kern/kern_mutex.c:654 > >>#12 0xffffffff80767b1b in mnt_vnode_next_active_relock ( > >> mvp=0xfffff80002449800, mp=0xfffff80132d1e000, > >vp=0xfffff80132e4eb40) > >> at /opt/src/svn-current/sys/kern/vfs_subr.c:5590 > >>#13 mnt_vnode_next_active (mvp=, mp=0xfffff80132d1e000) > >> at /opt/src/svn-current/sys/kern/vfs_subr.c:5649 > >>#14 0xffffffff80766206 in __mnt_vnode_next_active > >>(mvp=0xfffff80002449800, > >> mp=) at > >/opt/src/svn-current/sys/kern/vfs_subr.c:5682 > >>#15 vfs_msync (mp=0xfffff80132d1e000, flags=2) > >> at /opt/src/svn-current/sys/kern/vfs_subr.c:4238 > >>#16 0xffffffff8076b4a6 in sync_fsync (ap=) > >> at /opt/src/svn-current/sys/kern/vfs_subr.c:4468 > >>#17 0xffffffff80a7be46 in VOP_FSYNC_APV ( > >> vop=0xffffffff80cb4120 , a=0xfffffe004b3faa08) > >> at vnode_if.c:1312 > >>#18 0xffffffff80769319 in VOP_FSYNC (vp=, waitfor=3, > >> td=0xfffff800061dc5a0) at ./vnode_if.h:549 > >>#19 sync_vnode (bo=, td=0xfffff800061dc5a0, > >> slp=) at > >/opt/src/svn-current/sys/kern/vfs_subr.c:2316 > >>#20 sched_sync () at /opt/src/svn-current/sys/kern/vfs_subr.c:2418 > >>#21 0xffffffff80647e33 in fork_exit (callout=0xffffffff80768fa0 > >>, > >> arg=0x0, frame=0xfffffe004b3faac0) > >> at /opt/src/svn-current/sys/kern/kern_fork.c:1045 > >>#22 > >> > >> > >>dmesg output: > >> > >>Updating motd:. > >>Mounting late filesystems:. > >>Starting nscd. > >>Security policy loaded: MAC/ntpd (mac_ntpd) > >>Starting ntpd. > >>Starting yppasswdd. > >>kernel trap 12 with interrupts disabled > >> > >> > >>Fatal trap 12: page fault while in kernel mode > >>cpuid = 0; apic id = 00 > >>fault virtual address = 0xc > >>fault code = supervisor read data, page not present > >>instruction pointer = 0x20:0xffffffff806f0633 > >>stack pointer = 0x28:0xfffffe004b7fa7c0 > >>frame pointer = 0x28:0xfffffe004b7fa7e0 > >>code segment = base 0x0, limit 0xfffff, type 0x1b > >> = DPL 0, pres 1, long 1, def32 0, gran 1 > >>processor eflags = resume, IOPL = 0 > >>current process = 26 (syncer) > >>trap number = 12 > >>panic: page fault > >>cpuid = 0 > >>time = 1566820700 > >>KDB: stack backtrace: > >>db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > >>0xfffffe004b7fa470 > >>vpanic() at vpanic+0x19d/frame 0xfffffe004b7fa4c0 > >>panic() at panic+0x43/frame 0xfffffe004b7fa520 > >>trap_fatal() at trap_fatal+0x39c/frame 0xfffffe004b7fa580 > >>trap_pfault() at trap_pfault+0x49/frame 0xfffffe004b7fa5e0 > >>trap() at trap+0x29d/frame 0xfffffe004b7fa6f0 > >>calltrap() at calltrap+0x8/frame 0xfffffe004b7fa6f0 > >>--- trap 0xc, rip = 0xffffffff806f0633, rsp = 0xfffffe004b7fa7c0, rbp > >= > >>0xfffffe004b7fa7e0 --- > >>propagate_priority() at propagate_priority+0x153/frame > >>0xfffffe004b7fa7e0 > >>turnstile_wait() at turnstile_wait+0x32b/frame 0xfffffe004b7fa830 > >>__mtx_lock_sleep() at __mtx_lock_sleep+0x191/frame 0xfffffe004b7fa8c0 > >>mnt_vnode_next_active() at mnt_vnode_next_active+0x2cb/frame > >>0xfffffe004b7fa920 > >>vfs_msync() at vfs_msync+0x266/frame 0xfffffe004b7fa980 > >>sync_fsync() at sync_fsync+0xe6/frame 0xfffffe004b7fa9c0 > >>--- trap 0, rip = 0, rsp = 0, rbp = 0 --- > >>Uptime: 1m38s > >>Dumping 810 out of 7974 > >>MB:..2%..12%..22%..32%..42%..52%..62%..72%..81%..91%---<>--- > > > >This may be a simple case of increasing the kernel stack. I'll try this > >at noon. > > Increasing kernel stack pages from 8 to 20 still results in the panic. Pfft. Obviously. td->td_blocked is NULL. I've run out of noon hour but I'll put this out there even if this is half baked and not fully analyzed (got to get back to $JOB) but td->td_turnstile is NULL at frame 11. -- Cheers, Cy Schubert FreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.