Issue

• When a process is run on an NFSv4 directory, system hangs with no response, several minutes later, netdump will trigger kernel crash. Here is the oops message and call trace:

nfs: server s0054 not responding, still trying
nfs: server s0054 OK
NFS: v4 raced in function nfs4_proc_file_open
Unable to handle kernel paging request at 0000000100000000
RIP: <ffffffffa02c9110>{:nfs:put_nfs_open_context+70}
PML4 1b3e9067 PGD 0
Oops: 0002 [1] SMP
CPU 2
Modules linked in: netconsole netdump autofs4 i2c_dev i2c_core nfs lockd
nfs_acl sunrpc ib_srp ib_sdp ib_ipoib inet_lro md5 ipv6 rdma_ucm rdma_cm
iw_cm ib_addr ib_umad ib_ucm ib_uverbs ib_cm ib_sa ib_mad ib_core dm_mirror
dm_multipath dm_mod joydev button battery ac ehci_hcd uhci_hcd bnx2x
libcrc32c ext3 jbd cciss sd_mod scsi_mod
Pid: 13886, comm: proteus Not tainted 2.6.9-89.ELlargesmp
RIP: 0010:[<ffffffffa02c9110>]
<ffffffffa02c9110>{:nfs:put_nfs_open_context+70}
RSP: 0018:00000100cacbfdf8  EFLAGS: 00010246
RAX: 00000101826e3e30 RBX: 0000010138b4a7b4 RCX: ffffffff803f7ee8
RDX: 0000000100000000 RSI: 0000000000000246 RDI: 0000010138b4a7b4
RBP: 00000101826e3e00 R08: ffffffff803f7ee8 R09: 000001040aa272c0
R10: 0000000100000000 R11: 0000000000000000 R12: 00000101826e3e38
R13: 0000010138b4a708 R14: 00000102e5408000 R15: 0000010392df7c78
FS:  0000000041e02960(005b) GS:ffffffff80517480(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000100000000 CR3: 0000000006b6e000 CR4: 00000000000006e0 Process
proteus (pid: 13886, threadinfo 00000100cacbe000, task
000001033f73a030)
Stack: 000001040aa272c0 00000101826e3e00 000001021973c880 ffffffffa02d9443
       0000000000000000 0000000000000000 0000010138b4a708 000001021973c880
       000001040e64b080 ffffffffa02c7788 Call Trace:
<ffffffffa02d9443>{:nfs:nfs4_proc_file_open+238}
<ffffffffa02c7788>{:nfs:nfs_file_open+138}
<ffffffff8017adf1>{__dentry_open+208}
<ffffffff8017afca>{filp_open+95}
<ffffffff801361dc>{autoremove_wake_function+0}
<ffffffff801968cd>{dnotify_parent+34}
<ffffffff801f1e35>{strncpy_from_user+74}
<ffffffff8017b1b9>{sys_open+57}
<ffffffff801102f6>{system_call+126}

Code: 48 89 02 49 c7 44 24 08 00 02 20 00 48 c7 45 38 00 01 10 00 RIP
<ffffffffa02c9110>{:nfs:put_nfs_open_context+70} RSP <00000100cacbfdf8>
CR2: 0000000100000000