Hi folks,

I believe we've been hitting the same issue that
Gabriel Barazer reported in 2.6.28.9 on the 22nd
of July on our NFS server for our HPC Linux clusters.

Here is the backtrace we got this morning:

Aug  5 11:44:27 stg7 kernel: [680506.864506] Pid: 5271, comm: nfsd Not tainted 2.6.28.10-vpac-1 #1
Aug  5 11:44:27 stg7 kernel: [680506.864508] Call Trace:
Aug  5 11:44:27 stg7 kernel: [680506.864541]  [<ffffffffa032c8d5>] xfs_rename+0x5ac/0x5af [xfs]
Aug  5 11:44:27 stg7 kernel: [680506.864567]  [<ffffffffa032d793>] xfs_trans_cancel+0x56/0xee [xfs]
Aug  5 11:44:27 stg7 kernel: [680506.864589]  [<ffffffffa032c8d5>] xfs_rename+0x5ac/0x5af [xfs]
Aug  5 11:44:27 stg7 kernel: [680506.864609]  [<ffffffffa033b8d0>] xfs_vn_rename+0x61/0x69 [xfs]
Aug  5 11:44:27 stg7 kernel: [680506.864615]  [<ffffffff8029a798>] vfs_rename+0x28a/0x404
Aug  5 11:44:27 stg7 kernel: [680506.864642]  [<ffffffffa045322c>] nfsd_rename+0x2ba/0x35f [nfsd]
Aug  5 11:44:27 stg7 kernel: [680506.864654]  [<ffffffffa045a898>] nfsd3_proc_rename+0x120/0x131 [nfsd]
Aug  5 11:44:27 stg7 kernel: [680506.864681]  [<ffffffffa044f23b>] nfsd_dispatch+0xdd/0x1b9 [nfsd]
Aug  5 11:44:27 stg7 kernel: [680506.864706]  [<ffffffffa03b3cdd>] svc_process+0x3e6/0x70e [sunrpc]
Aug  5 11:44:27 stg7 kernel: [680506.864711]  [<ffffffff8022f9f2>] default_wake_function+0x0/0xe
Aug  5 11:44:27 stg7 kernel: [680506.864717]  [<ffffffff8040dfac>] __down_read+0x15/0x99
Aug  5 11:44:27 stg7 kernel: [680506.864740]  [<ffffffffa044f7d1>] nfsd+0x1a0/0x26c [nfsd]
Aug  5 11:44:27 stg7 kernel: [680506.864750]  [<ffffffffa044f631>] nfsd+0x0/0x26c [nfsd]
Aug  5 11:44:27 stg7 kernel: [680506.864754]  [<ffffffff802470de>] kthread+0x47/0x73
Aug  5 11:44:27 stg7 kernel: [680506.864757]  [<ffffffff80232f9a>] schedule_tail+0x27/0x60
Aug  5 11:44:27 stg7 kernel: [680506.864761]  [<ffffffff8020ccd9>] child_rip+0xa/0x11
Aug  5 11:44:27 stg7 kernel: [680506.864764]  [<ffffffff80247097>] kthread+0x0/0x73
Aug  5 11:44:27 stg7 kernel: [680506.864766]  [<ffffffff8020cccf>] child_rip+0x0/0x11
Aug  5 11:44:27 stg7 kernel: [680506.864770] xfs_force_shutdown(md25,0x8) called from line 1165 of file fs/xfs/xfs
_trans.c.  Return address = 0xffffffffa032d7ac

Here's another backtrace from a week ago (same kernel):

Jul 28 13:27:22 stg7 kernel: [3528649.232700] Pid: 5414, comm: nfsd Not tainted 2.6.28.10-vpac-1 #1
Jul 28 13:27:22 stg7 kernel: [3528649.232702] Call Trace:
Jul 28 13:27:22 stg7 kernel: [3528649.232734]  [<ffffffffa03728d5>] xfs_rename+0x5ac/0x5af [xfs]
Jul 28 13:27:22 stg7 kernel: [3528649.232756]  [<ffffffffa0373793>] xfs_trans_cancel+0x56/0xee [xfs]
Jul 28 13:27:22 stg7 kernel: [3528649.232778]  [<ffffffffa03728d5>] xfs_rename+0x5ac/0x5af [xfs]
Jul 28 13:27:22 stg7 kernel: [3528649.232809]  [<ffffffffa03818d0>] xfs_vn_rename+0x61/0x69 [xfs]
Jul 28 13:27:22 stg7 kernel: [3528649.232814]  [<ffffffff8029a798>] vfs_rename+0x28a/0x404
Jul 28 13:27:22 stg7 kernel: [3528649.232829]  [<ffffffffa03f822c>] nfsd_rename+0x2ba/0x35f [nfsd]
Jul 28 13:27:22 stg7 kernel: [3528649.232855]  [<ffffffffa03ff898>] nfsd3_proc_rename+0x120/0x131 [nfsd]
Jul 28 13:27:22 stg7 kernel: [3528649.232879]  [<ffffffffa03f423b>] nfsd_dispatch+0xdd/0x1b9 [nfsd]
Jul 28 13:27:22 stg7 kernel: [3528649.232902]  [<ffffffffa03abcdd>] svc_process+0x3e6/0x70e [sunrpc]
Jul 28 13:27:22 stg7 kernel: [3528649.232907]  [<ffffffff8022f9f2>] default_wake_function+0x0/0xe
Jul 28 13:27:22 stg7 kernel: [3528649.232912]  [<ffffffff8040dfac>] __down_read+0x15/0x99
Jul 28 13:27:22 stg7 kernel: [3528649.232922]  [<ffffffffa03f47d1>] nfsd+0x1a0/0x26c [nfsd]
Jul 28 13:27:22 stg7 kernel: [3528649.232948]  [<ffffffffa03f4631>] nfsd+0x0/0x26c [nfsd]
Jul 28 13:27:22 stg7 kernel: [3528649.232952]  [<ffffffff802470de>] kthread+0x47/0x73
Jul 28 13:27:22 stg7 kernel: [3528649.232955]  [<ffffffff80232f9a>] schedule_tail+0x27/0x60
Jul 28 13:27:22 stg7 kernel: [3528649.232959]  [<ffffffff8020ccd9>] child_rip+0xa/0x11
Jul 28 13:27:22 stg7 kernel: [3528649.232962]  [<ffffffff80247097>] kthread+0x0/0x73
Jul 28 13:27:22 stg7 kernel: [3528649.232964]  [<ffffffff8020cccf>] child_rip+0x0/0x11
Jul 28 13:27:22 stg7 kernel: [3528649.232967] xfs_force_shutdown(md25,0x8) called from line 1165 of file fs/xfs/xf
s_trans.c.  Return address = 0xffffffffa03737ac

This kernel is built with XFS as a kernel module so I've
been able to attach the objdump output that Eric Sandeen
had originally requested from Gabriel.

Like Gabriel we're stuck on 2.6.28.x as the last working
NFS exporting XFS kernel due to kernel bug #13375 (the
radix bug), so I hope this helps!

cheers,
Chris
-- 
Christopher Samuel - (03) 9925 4751 - Systems Manager
 The Victorian Partnership for Advanced Computing
 P.O. Box 201, Carlton South, VIC 3053, Australia
VPAC is a not-for-profit Registered Research Agency