svn commit: r351472 - head/sys/fs/nullfs
Mateusz Guzik
mjguzik at gmail.com
Tue Aug 27 00:52:15 UTC 2019
Sorry for the half-assed patch. I have a patch to remove the flags
argument and the change above was port of it.
Try this please:
https://people.freebsd.org/~mjg/patches/vop_unlock-interlock2.diff
On 8/27/19, Cy Schubert <cy.schubert at gmail.com> wrote:
> It won't build. Did you intend VOP_UNLOCK(vp,LK_INTERLOCK)?
>
> --- vfs_subr.o ---
> /opt/src/svn-current/sys/kern/vfs_subr.c:1037:17: error: too few arguments
> to function call, expected 2, have 1
> VOP_UNLOCK(vp);
> ~~~~~~~~~~ ^
> ./vnode_if.h:873:1: note: 'VOP_UNLOCK' declared here
> static __inline int VOP_UNLOCK(
> ^
> /opt/src/svn-current/sys/kern/vfs_subr.c:1401:16: error: too few arguments
> to function call, expected 2, have 1
> VOP_UNLOCK(vp);
> ~~~~~~~~~~ ^
> ./vnode_if.h:873:1: note: 'VOP_UNLOCK' declared here
> static __inline int VOP_UNLOCK(
> ^
> /opt/src/svn-current/sys/kern/vfs_subr.c:1413:15: error: too few arguments
> to function call, expected 2, have 1
> VOP_UNLOCK(vp);
> ~~~~~~~~~~ ^
> ./vnode_if.h:873:1: note: 'VOP_UNLOCK' declared here
> static __inline int VOP_UNLOCK(
> ^
> 3 errors generated.
> *** [vfs_subr.o] Error code 1
>
> make[2]: stopped in /export/obj/opt/src/svn-current/amd64.amd64/sys/BREAK
>
>
> --
> Cheers,
> Cy Schubert <Cy.Schubert at cschubert.com>
> FreeBSD UNIX: <cy at FreeBSD.org> Web: http://www.FreeBSD.org
>
> The need of the many outweighs the greed of the few.
>
>
> In message
> <CAGudoHHGLguWZZMh+TOCBwANKKp7-6z5JvP1NgRo3jAr4vZ+Pw at mail.gmail.c
> om>
> , Mateusz Guzik writes:
>> Does this do the trick for you?
>>
>> https://people.freebsd.org/~mjg/vop_unlock-interlock.diff
>>
>> On 8/26/19, Cy Schubert <Cy.Schubert at cschubert.com> wrote:
>> > On August 26, 2019 8:40:50 AM PDT, Cy Schubert
>> > <Cy.Schubert at cschubert.com>
>> > wrote:
>> >>On August 26, 2019 7:11:22 AM PDT, Cy Schubert
>> >><Cy.Schubert at cschubert.com> wrote:
>> >>>In message <6C6BF3A4-DC07-4D9A-9A5F-FA075BF535A8 at cschubert.com>, Cy
>> >>>Schubert wr
>> >>>ites:
>> >>>> On August 24, 2019 10:13:15 PM PDT, Mateusz Guzik <mjg at FreeBSD.org>
>> >>>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=<optimized out>, ap=<optimized
>> >>>out>)
>> >>> at /opt/src/svn-current/sys/kern/kern_shutdown.c:905
>> >>>#4 0xffffffff8068b163 in panic (fmt=<unavailable>)
>> >>> 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 <signal handler called>
>> >>>#9 propagate_priority (td=0xfffff8003e43b000)
>> >>> at /opt/src/svn-current/sys/kern/subr_turnstile.c:279
>> >>>#10 0xffffffff806f13db in turnstile_wait (ts=0xfffff8000258a780,
>> >>> owner=<optimized out>, queue=-512)
>> >>> at /opt/src/svn-current/sys/kern/subr_turnstile.c:785
>> >>>#11 0xffffffff80669271 in __mtx_lock_sleep (c=0xfffff80132e4ebf0,
>> >>> v=<optimized out>) 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=<optimized out>, mp=0xfffff80132d1e000)
>> >>> at /opt/src/svn-current/sys/kern/vfs_subr.c:5649
>> >>>#14 0xffffffff80766206 in __mnt_vnode_next_active
>> >>>(mvp=0xfffff80002449800,
>> >>> mp=<optimized out>) 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=<optimized out>)
>> >>> at /opt/src/svn-current/sys/kern/vfs_subr.c:4468
>> >>>#17 0xffffffff80a7be46 in VOP_FSYNC_APV (
>> >>> vop=0xffffffff80cb4120 <sync_vnodeops>, a=0xfffffe004b3faa08)
>> >>> at vnode_if.c:1312
>> >>>#18 0xffffffff80769319 in VOP_FSYNC (vp=<optimized out>, waitfor=3,
>> >>> td=0xfffff800061dc5a0) at ./vnode_if.h:549
>> >>>#19 sync_vnode (bo=<optimized out>, td=0xfffff800061dc5a0,
>> >>> slp=<optimized out>) 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
>> >>><sched_sync>,
>> >>> arg=0x0, frame=0xfffffe004b3faac0)
>> >>> at /opt/src/svn-current/sys/kern/kern_fork.c:1045
>> >>>#22 <signal handler called>
>> >>>
>> >>>
>> >>>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%---<<BOOT>>---
>> >>
>> >>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.
>> >
>> >
>> > --
>> > Pardon the typos and autocorrect, small keyboard in use.
>> > Cheers,
>> > Cy Schubert <Cy.Schubert at cschubert.com>
>> > FreeBSD UNIX: <cy at FreeBSD.org> Web: http://www.FreeBSD.org
>> >
>> > The need of the many outweighs the greed of the few.
>> >
>>
>>
>> --
>> Mateusz Guzik <mjguzik gmail.com>
>
>
>
--
Mateusz Guzik <mjguzik gmail.com>
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