Re: 4.0 kernel XFS filesystem crash when running AIM7's disk workload

[Waiman Long]

On 04/17/2015 07:45 PM, Dave Chinner wrote:
> On Fri, Apr 17, 2015 at 01:38:49PM -0400, Waiman Long wrote:
> > Hi Dave,
> >
> > When I was running the AIM7's disk workload on a 8-socket
> > Westmere-EX server with 4.0 kernel, the kernel crash. A set of small
> > ramdisks were created (ramdisk_size=271072). Those ramdisks were
> > formatted with XFS filesystem before the test began. The kernel log
> > was:
> >
> > XFS (ram12): Mounting V4 Filesystem
> > XFS (ram12): Log size 1424 blocks too small, minimum size is 1596 blocks
> > XFS (ram12): Log size out of supported range. Continuing onwards,
> > but if log hangs are
> > experienced then please report this message in the bug report.
> First thing you need to do is upgrade xfsprogs so that this message
> goes away. or use "mkfs.xfs -l size=10m" so that the log is larger
> than the minimum.
>
> > XFS (ram15): Ending clean mount
> > BUG: unable to handle kernel NULL pointer dereference at           (null)
> > IP: [<ffffffff812abd6d>] __memcpy+0xd/0x110
> > PGD 29f7655f067 PUD 29f75a80067 PMD 0
> > Oops: 0000 [#1] SMP
> > Modules linked in: xfs exportfs libcrc32c ebtable_nat ebtables
> > xt_CHECKSUM iptable_mangle bridge stp llc autofs4 ipt_REJECT
> > nf_reject_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter
> > ip_tables ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6
> > nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6
> > vhost_net macvtap macvlan vhost tun kvm_intel kvm ipmi_si
> > ipmi_msghandler tpm_infineon iTCO_wdt iTCO_vendor_support wmi
> > acpi_cpufreq microcode pcspkr serio_raw qlcnic be2net vxlan
> > udp_tunnel ip6_udp_tunnel ses enclosure igb dca ptp pps_core lpc_ich
> > mfd_core hpilo hpwdt sg i7core_edac edac_core netxen_nic ext4(E)
> > jbd2(E) mbcache(E) sr_mod(E) cdrom(E) sd_mod(E) lpfc(E) qla2xxx(E)
> > scsi_transport_fc(E) pata_acpi(E) ata_generic(E) ata_piix(E) hpsa(E)
> > radeon(E) ttm(E) drm_kms_helper(E) drm(E) i2c_algo_bit(E)
> > i2c_core(E) dm_mirror(E) dm_region_hash(E) dm_log(E) dm_mod(E)
> Why do you have a mix of signed and unsigned modules loaded?

I did the test on a RHEL 6.6 system. The 4.0 kernel is unsigned, but 
there are some additional RHEL modules loaded at boot up time.

> > CPU: 69 PID: 116603 Comm: xfsaild/ram5 Tainted: G            E   4.0.0 #2
> > Hardware name: HP ProLiant DL980 G7, BIOS P66 07/30/2012
> > task: ffff8b9f7eeb4f80 ti: ffff8b9f7f1ac000 task.ti: ffff8b9f7f1ac000
> > RIP: 0010:[<ffffffff812abd6d>]  [<ffffffff812abd6d>] __memcpy+0xd/0x110
> > RSP: 0018:ffff8b9f7f1afc10  EFLAGS: 00010206
> > RAX: ffff88102476a3cc RBX: ffff889ff2ab5000 RCX: 0000000000000005
> > RDX: 0000000000000006 RSI: 0000000000000000 RDI: ffff88102476a3cc
> edx = 6 bytes.
>
> > RBP: ffff8b9f7f1afc18 R08: 0000000000000001 R09: ffff88102476a3cc
> > R10: ffff8a1f6c03ea80 R11: 0000000000000000 R12: ffff8b1ff1269400
> > R13: ffff8b1f64837c98 R14: ffff881038701200 R15: ffff88102476a300
> > FS:  0000000000000000(0000) GS:ffff8b1fffa40000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> > CR2: 0000000000000000 CR3: 0000029f7655e000 CR4: 00000000000006e0
> > Stack:
> >   ffffffffa0ca8c41 ffff8b9f7f1afc68 ffffffffa0cc4803 ffff8b9f7f1afc68
> >   ffffffffa0cd2777 ffff8b9f7f1afc68 ffff8b1ff1269400 ffff8a9f59022800
> >   ffff8b1f7c932718 0000000000000003 ffff8a9f590228e4 ffff8b9f7f1afce8
> > Call Trace:
> >   [<ffffffffa0ca8c41>] ? xfs_iflush_fork+0x181/0x240 [xfs]
> >   [<ffffffffa0cc4803>] xfs_iflush_int+0x1f3/0x320 [xfs]
> >   [<ffffffffa0cd2777>] ? kmem_alloc+0x87/0x100 [xfs]
> >   [<ffffffffa0cc60a5>] xfs_iflush_cluster+0x295/0x380 [xfs]
> >   [<ffffffffa0cc8ff4>] xfs_iflush+0xf4/0x1f0 [xfs]
> >   [<ffffffffa0cda22a>] xfs_inode_item_push+0xea/0x130 [xfs]
> >   [<ffffffffa0ce140d>] xfsaild_push+0x10d/0x500 [xfs]
> >   [<ffffffff810b7c20>] ? lock_timer_base+0x70/0x70
> >   [<ffffffffa0ce1898>] xfsaild+0x98/0x130 [xfs]
> >   [<ffffffffa0ce1800>] ? xfsaild_push+0x500/0x500 [xfs]
> >   [<ffffffffa0ce1800>] ? xfsaild_push+0x500/0x500 [xfs]
> >   [<ffffffffa0ce1800>] ? xfsaild_push+0x500/0x500 [xfs]
> >   [<ffffffff81074b50>] ? kthread_freezable_should_stop+0x70/0x70
> >   [<ffffffff815c5748>] ret_from_fork+0x58/0x90
> >   [<ffffffff81074b50>] ? kthread_freezable_should_stop+0x70/0x70
> > Code: 0f b6 c0 5b c9 c3 0f 1f 84 00 00 00 00 00 e8 2b f9 ff ff 80 7b
> > 25 00 74 c8 eb d3 90 90 90 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07
> > <f3>  48 a5 89 d1 f3 a4 c3 20 4c 8b 06 4c 8b 4e 08 4c 8b 56 10 4c
> > RIP  [<ffffffff812abd6d>] __memcpy+0xd/0x110
> >   RSP<ffff8b9f7f1afc10>
> > CR2: 0000000000000000
> > ---[ end trace fb8a4add69562a76 ]---
> >
> > The xfs_iflush_fork+0x181/0x240 (385) IP address is at:
> (rearrange slightly to make more sense)
>
> > 823        case XFS_DINODE_FMT_LOCAL:
> > 824            if ((iip->ili_fields&  dataflag[whichfork])&&
> >     0x00000000000023c0<+336>:    movslq %ecx,%rcx
> >     0x00000000000023c3<+339>:    movswl 0x0(%rcx,%rcx,1),%eax
> >     0x00000000000023cb<+347>:    test   %eax,0x90(%rdx)
> >     0x00000000000023d1<+353>:    je     0x2350<xfs_iflush_fork+224>
> >
> > 825                (ifp->if_bytes>  0)) {
> >     0x00000000000023d7<+359>:    mov    (%r10),%edx
> >     0x00000000000023da<+362>:    test   %edx,%edx
> >     0x00000000000023dc<+364>:    jle    0x2350<xfs_iflush_fork+224>
> So the contents of rdx says that the inode fork size is 6 bytes in
> local format. The call location also indicates that it is the
> attribute fork that is in being flushed. The minimum size of the
> attr fork is 3 bytes - an empty header. However, then ext valid size
> has a second header that adds 4 bytes to the size, plus the bytes
> inteh attr name and value.
>
> Hence a size of 6 bytes is invalid, and probably indicates that
> there is some form of memory corruption going on here.
>
> IIRC, we haven't touched this code for a while - can you test 3.19
> and see if it has the same problem? If it doesn't have the problem,
> and given you can reliably reproduce the crash, can you run a
> bisect to find the cause?

I have done the bisection and the following commit in 3.13 is the one 
that cause the problem, I think:

f7be2d7f594cbc7a00902b5427332a1ad519a528
xfs: push down inactive transaction mgmt for truncate

I looked at the patch, and it didn't seem quite right, but I don't know 
much about the XFS internal to be sure. Maybe you can take a look at that.

Cheers,
Longman


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