From: "J. Bruce Fields" <bfields@fieldses.org>
Subject: Re: 2.6.26 stable kernel crash with NFS exporting a XFS share
Date: Mon, 4 Aug 2008 13:53:32 -0400
Message-ID: <20080804175332.GC25940@fieldses.org>
References: <4893CACA.1060605@cse.unsw.edu.au>
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Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
To: Shehjar Tikoo <shehjart@cse.unsw.edu.au>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
In-Reply-To: <4893CACA.1060605@cse.unsw.edu.au>
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-nfs.vger.kernel.org>

On Sat, Aug 02, 2008 at 12:47:38PM +1000, Shehjar Tikoo wrote:
> Hi All
>
> Please see the attached text file which contains
> details of a crash I observed recently while
> running some tests against Linux nfsd with
> XFS as the file system. Details are all there in
> the file.
>
>
> -Shehjar

> Kernel 2.6.26 stable on both client and server
> sunrpc.tcp_slot_table_entries=96
> NFS wsize=32k
> Server file system = XFS over software raid0 w/ 3 10k RPM SAS disks
> nfsd threads = 512
> Gbit network w/ Jumbo frames
> Workload:
> Iozone 1-20 writer processes
> write() syscall record/buffer size= 50Megs
> File size = 500Megs
> Server machine is a 2xDual Core Itanium 2 with 8Gigs of RAM, so in theory, maximum memory pressure
> will be for (500Megs * 20 Processes)
> Client machine is a 4xDual Core Itanium 2 with 16Gigs of RAM.
> 
> 
> Remarks:
> 1. The crash is preceded by hundreds of lines which look like this:
> Filesystem "md0": Access to block zero in inode 271 start_block: 0 start_off: 0 blkcnt: 0 extent-   state: 0 lastx: fa

So that's an xfs_cmn_err() in
fs/xfs/xfs_map.c:xfs_bmap_search_extents().  Is there an xfs developer
that could explain what that likely means?

--b.

> 
> 2. Cannot be reproduced on every run of the above workload. Disk corruption?
> 
> 
> The stack trace:
> ================
> Unable to handle kernel paging request at virtual address 000000000153e1ff
> nfsd[10703]: Oops 11012296146944 [1]
> 
> Pid: 10703, CPU 1, comm:                 nfsd
> psr : 00001210085a2010 ifs : 800000000000038c ip  : [<a000000100149551>]    Not tainted (2.6.26)
> ip is at __kmalloc+0x131/0x220
> unat: 0000000000000000 pfs : 000000000000038c rsc : 0000000000000003
> rnat: a0000001004c0780 bsps: a0000001001a8060 pr  : 666a96a6a5996665
> ldrs: 0000000000000000 ccv : 0000000000000002 fpsr: 0009804c8a70433f
> csd : 0000000000000000 ssd : 0000000000000000
> b0  : a0000001001494c0 b6  : a0000001004c0780 b7  : a0000001003b4520
> f6  : 0fff7810204080f809f84 f7  : 0ffdf9d24f78a00000000
> f8  : 10006fe00000000000000 f9  : 10006fe00000000000000
> f10 : 0fffefffffffffec33c8a f11 : 1003e0000000000000001
> r1  : a0000001011f1c80 r2  : 0000000000508040 r3  : e0000001951b8014
> r8  : a000000100f26060 r9  : e000000100015c18 r10 : a000000100f26150
> r11 : 000000000000001d r12 : e0000001951bf8b0 r13 : e0000001951b8000
> r14 : 00000000000000c0 r15 : a000000100f26068 r16 : 0000000000000001
> r17 : 0000000000000001 r18 : e0000001951b8c04 r19 : a000000100ff21f0
> r20 : 000000000153e1ff r21 : 0000000000000000 r22 : e000000100015c14
> r23 : 0000000000000000 r24 : 00000000000000ff r25 : 000000000000000e
> r26 : e000010040919a72 r27 : 0000000000000000 r28 : 0000000000000100
> r29 : 0000000000000101 r30 : e0000001551e93ec r31 : 000ffffffffe0000
> 
> Call Trace:
>  [<a000000100014090>] show_stack+0x50/0xa0
>                                 sp=e0000001951bf480 bsp=e0000001951b9bc0
>  [<a0000001000148e0>] show_regs+0x800/0x840
>                                 sp=e0000001951bf650 bsp=e0000001951b9b68
>  [<a000000100038ca0>] die+0x1a0/0x2c0
>                                 sp=e0000001951bf650 bsp=e0000001951b9b28
>  [<a00000010005a5d0>] ia64_do_page_fault+0x8b0/0x9e0
>                                 sp=e0000001951bf650 bsp=e0000001951b9ad8
>  [<a00000010000b140>] ia64_leave_kernel+0x0/0x270
>                                 sp=e0000001951bf6e0 bsp=e0000001951b9ad8
>  [<a000000100149550>] __kmalloc+0x130/0x220
>                                 sp=e0000001951bf8b0 bsp=e0000001951b9a78
>  [<a0000001004b49a0>] kmem_alloc+0x140/0x2a0
>                                 sp=e0000001951bf8b0 bsp=e0000001951b9a38
>  [<a00000010046f400>] xfs_iext_add_indirect_multi+0xa0/0x440
>                                 sp=e0000001951bf8b0 bsp=e0000001951b99c0
>  [<a000000100471d80>] xfs_iext_add+0x3e0/0x4a0
>                                 sp=e0000001951bf8b0 bsp=e0000001951b9968
>  [<a000000100471e70>] xfs_iext_insert+0x30/0xc0
>                                 sp=e0000001951bf8c0 bsp=e0000001951b9930
>  [<a000000100426560>] xfs_bmap_add_extent_hole_delay+0x6e0/0x7c0
>                                 sp=e0000001951bf8c0 bsp=e0000001951b98b0
>  [<a00000010042af60>] xfs_bmap_add_extent+0x2a0/0x7a0
>                                 sp=e0000001951bf900 bsp=e0000001951b9820
>  [<a000000100432300>] xfs_bmapi+0x1020/0x1c40
>                                 sp=e0000001951bf950 bsp=e0000001951b95a0
>  [<a00000010047db60>] xfs_iomap_write_delay+0x2e0/0x400
>                                 sp=e0000001951bfa20 bsp=e0000001951b94a8
>  [<a00000010047e000>] xfs_iomap+0x380/0x520
>                                 sp=e0000001951bfaf0 bsp=e0000001951b9448
>  [<a0000001004b5ac0>] __xfs_get_blocks+0xc0/0x560
>                                 sp=e0000001951bfb40 bsp=e0000001951b93e8
>  [<a0000001004b6000>] xfs_get_blocks+0x40/0x60
>                                 sp=e0000001951bfb80 bsp=e0000001951b93b0
>  [<a0000001001ab4c0>] __block_prepare_write+0x400/0xa80
>                                 sp=e0000001951bfb80 bsp=e0000001951b92d0
>  [<a0000001001abea0>] block_write_begin+0x100/0x1e0
>                                 sp=e0000001951bfba0 bsp=e0000001951b9260
>  [<a0000001004b8b30>] xfs_vm_write_begin+0x50/0x80
>                                 sp=e0000001951bfba0 bsp=e0000001951b9210
>  [<a0000001000f3df0>] generic_file_buffered_write+0x1d0/0xe00
>                                 sp=e0000001951bfba0 bsp=e0000001951b9108
>  [<a0000001004c8c10>] xfs_write+0x910/0xd80
>                                 sp=e0000001951bfbd0 bsp=e0000001951b8fc8
>  [<a0000001004c0230>] xfs_file_aio_write+0xf0/0x120
>                                 sp=e0000001951bfc20 bsp=e0000001951b8f90
>  [<a000000100150100>] do_sync_readv_writev+0x140/0x1c0
>                                 sp=e0000001951bfc20 bsp=e0000001951b8f40
>  [<a000000100151080>] do_readv_writev+0x160/0x280
>                                 sp=e0000001951bfd10 bsp=e0000001951b8ef0
>  [<a000000100151260>] vfs_writev+0xc0/0x100
>                                 sp=e0000001951bfda0 bsp=e0000001951b8eb8
>  [<a0000001003a3080>] nfsd_vfs_write+0x200/0x660
>                                 sp=e0000001951bfda0 bsp=e0000001951b8e48
>  [<a0000001003a4800>] nfsd_write+0x140/0x1a0
>                                 sp=e0000001951bfe00 bsp=e0000001951b8de8
>  [<a0000001003b46d0>] nfsd3_proc_write+0x1b0/0x200
>                                 sp=e0000001951bfe10 bsp=e0000001951b8db0
>  [<a000000100398aa0>] nfsd_dispatch+0x220/0x4c0
>                                 sp=e0000001951bfe10 bsp=e0000001951b8d70
>  [<a000000100b768f0>] svc_process+0xc30/0x1b40
>                                 sp=e0000001951bfe10 bsp=e0000001951b8d18
>  [<a000000100399850>] nfsd+0x350/0x600
>                                 sp=e0000001951bfe20 bsp=e0000001951b8c88
>  [<a000000100012250>] kernel_thread_helper+0xd0/0x100
>                                 sp=e0000001951bfe30 bsp=e0000001951b8c60
>  [<a0000001000091a0>] start_kernel_thread+0x20/0x40
>                                 sp=e0000001951bfe30 bsp=e0000001951b8c60
>