Re: NFS oops in 2.6.26rc4

["Chuck Lever" <chuck.lever@oracle.com>]

Hi Dave-

On Tue, May 27, 2008 at 3:04 PM, Dave Jones <davej@redhat.com> wrote:
> When trying to mount an nfs export, I got this oops..
>
> BUG: unable to handle kernel paging request at f4569000
> IP: [<f8daac01>] :sunrpc:xdr_encode_opaque_fixed+0x2d/0x69
> *pde = 34c23163 *pte = 34569160
> Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
> Modules linked in: nfs nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ext2 sg button via_rhine via_ircc pcspkr r8169 mii pata_sil680 irda crc_ccitt i2c_viapro i2c_core dm_snapshot dm_zero dm_mirror dm_log dm_mod pata_via ata_generic pata_acpi libata sd_mod scsi_mod ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan]
>
> Pid: 2046, comm: mount.nfs Not tainted (2.6.26-0.33.rc4.fc10.i686 #1)
> EIP: 0060:[<f8daac01>] EFLAGS: 00210212 CPU: 0
> EIP is at xdr_encode_opaque_fixed+0x2d/0x69 [sunrpc]
> EAX: 0000f455 EBX: 00003d16 ECX: 0000349c EDX: 00000003
> ESI: f4569000 EDI: f4d2e450 EBP: f4566a78 ESP: f4566a68
>  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
> Process mount.nfs (pid: 2046, ti=f4566000 task=f4580000 task.ti=f4566000)
> Stack: f4d2c26c 55f40000 f4e740c0 f4e740c0 f4566a84 f8daac4f 0000f455 f4566a94
>       f8e7ec28 00000000 f4d00600 f4566aac f8da4db8 f8e7ec12 f4e740c0 f4e740c0
>       f4d00600 f4566acc f8d9ea9d f4d2c268 f4566e1a f8e7ec12 f4d00600 00000000
> Call Trace:
>  [<f8daac4f>] ? xdr_encode_opaque+0x12/0x15 [sunrpc]
>  [<f8e7ec28>] ? nfs3_xdr_fhandle+0x16/0x25 [nfs]
>  [<f8da4db8>] ? rpcauth_wrap_req+0x66/0x77 [sunrpc]
>  [<f8e7ec12>] ? nfs3_xdr_fhandle+0x0/0x25 [nfs]
>  [<f8d9ea9d>] ? call_transmit+0x18a/0x1eb [sunrpc]
>  [<f8e7ec12>] ? nfs3_xdr_fhandle+0x0/0x25 [nfs]
>  [<f8da4450>] ? __rpc_execute+0x69/0x1e1 [sunrpc]
>  [<f8da45e3>] ? rpc_execute+0x1b/0x1e [sunrpc]
>  [<f8d9f260>] ? rpc_run_task+0x43/0x49 [sunrpc]
>  [<f8d9f368>] ? rpc_call_sync+0x43/0x5e [sunrpc]
>  [<f8e7cf05>] ? nfs3_rpc_wrapper+0x17/0x4d [nfs]
>  [<f8e7d014>] ? nfs3_proc_fsinfo+0x5e/0x80 [nfs]
>  [<f8e6c64c>] ? nfs_probe_fsinfo+0x75/0x462 [nfs]
>  [<f8d9f3c4>] ? rpc_ping+0x41/0x4b [sunrpc]
>  [<f8d9f7c7>] ? rpc_bind_new_program+0x5b/0x71 [sunrpc]
>  [<f8e6de14>] ? nfs_create_server+0x451/0x5fd [nfs]
>  [<f8d9f4ef>] ? rpc_free_auth+0x33/0x36 [sunrpc]
>  [<c05025e5>] ? kref_put+0x39/0x44
>  [<f8d9f415>] ? rpc_release_client+0x47/0x4c [sunrpc]
>  [<f8d9f5a6>] ? rpc_shutdown_client+0xb4/0xbc [sunrpc]
>  [<f8e7cd39>] ? nfs_mount+0x12b/0x131 [nfs]
>  [<f8e74eb8>] ? nfs_get_sb+0x599/0x830 [nfs]
>  [<c04887c7>] ? check_object+0x134/0x18b
>  [<c0489995>] ? __slab_alloc+0x45c/0x4ea
>  [<c048a3a0>] ? __kmalloc+0xbc/0xfb
>  [<c044788f>] ? trace_hardirqs_on+0xe9/0x10a
>  [<c04a280c>] ? alloc_vfsmnt+0xe3/0x10a
>  [<c048f6b1>] ? vfs_kern_mount+0x82/0xf5
>  [<c048f768>] ? do_kern_mount+0x32/0xba
>  [<c04a2520>] ? do_new_mount+0x42/0x6c
>  [<c04a2fa0>] ? do_mount+0x199/0x1b7
>  [<c04a1626>] ? copy_mount_options+0x79/0xf9
>  [<c04a3024>] ? sys_mount+0x66/0x9e
>  [<c0404c3a>] ? syscall_call+0x7/0xb
>  =======================
> Code: e5 57 56 89 d6 53 83 ec 04 85 c9 89 45 f0 89 c8 74 4c 8d 59 03 c1 eb 02 8d 14 9d 00 00 00 00 29 ca 85 f6 74 11 c1 e9 02 8b 7d f0 <f3> a5 89 c1 83 e1 03 74 02 f3 a4 85 d2 74 1b 8b 7d f0 89 d1 c1
> EIP: [<f8daac01>] xdr_encode_opaque_fixed+0x2d/0x69 [sunrpc] SS:ESP 0068:f4566a68
> ---[ end trace a8a691a45122c25a ]---
> mount.nfs used greatest stack depth: 812 bytes left

The last line suggests you are trying this with 4KB kernel stacks.  I
have patches queued for .27 that provide some stack relief in this
code path.  If you hit this often, you might want to try with 8KB
stacks to see if that helps.

In the meantime, the traceback is a little funky, so I can't see
directly what the root cause is.  Can you provide the full command
line of the mount command that caused this?  What "brand" of server
were you trying to mount?  How often can you reproduce this?

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com