Issue

• After update to RHEL7.4 kernel, NFS4.1 client hangs with the NFS4 state manager thread inside nfs_reap_expired_delegations and a tcpdump shows a constant stream of TEST_STATEID with the same stateid sent, and a NFS4ERR_BAD_STATEID response.
• With NFS4.1 NFS client, after update to RHEL7.4, processes are hung and/or generate hung task error messages. Also, top shows the following process which has a name based on the IP address of the NFS server, is using the most CPU

(10.#.#.# is IP address of NAS):

          PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
        12073 root      20   0       0      0      0 D  16.7  0.0 525:23.29 10.#.#.#-manag

• After update to RHEL7.4 kernel, NFS4.0 seeing soft lockups in nfs_reap_expired_delegations and the NFS4.0 client hangs requiring a reboot or panics due to soft lockup

[17596.853096] NMI watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [10.1.1.42-ma:11637]
[17596.853853] Modules linked in: tcp_diag inet_diag rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache vmw_vsock_vmci_transport vsock sb_edac edac_core coretemp iosf_mbi crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd ppdev vmw_balloon joydev pcspkr sg parport_pc parport shpchp vmw_vmci i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sr_mod cdrom ata_generic pata_acpi vmwgfx drm_kms_helper sd_mod syscopyarea crc_t10dif sysfillrect crct10dif_generic sysimgblt fb_sys_fops ttm drm crct10dif_pclmul ata_piix crct10dif_common crc32c_intel libata serio_raw vmxnet3 vmw_pvscsi i2c_core floppy dm_mirror dm_region_hash dm_log dm_mod
[17596.853900] CPU: 1 PID: 11637 Comm: 172.32.55.22-ma Tainted: G             L ------------   3.10.0-693.1.1.el7.x86_64 #1
[17596.853901] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/17/2015
[17596.853903] task: ffff8804242f5ee0 ti: ffff8802cc220000 task.ti: ffff8802cc220000
[17596.853904] RIP: 0010:[<ffffffffc058489a>]  [<ffffffffc058489a>] nfs_reap_expired_delegations+0x9a/0x220 [nfsv4]
[17596.853921] RSP: 0018:ffff8802cc223df8  EFLAGS: 00000206
[17596.853922] RAX: 0000000000000004 RBX: ffff88041ce0d000 RCX: 0000000000000003
[17596.853923] RDX: 0000000000000000 RSI: ffff8800b769d848 RDI: ffff8800bb556000
[17596.853924] RBP: ffff8802cc223e58 R08: ffff88041be93540 R09: 0000000000000000
[17596.853925] R10: 0000000000000000 R11: 7fffffffffffffff R12: ffff88041ce0d000
[17596.853926] R13: ffffffffc0584a6d R14: ffff8802cc223d78 R15: ffff8800b769d7c0
[17596.853927] FS:  0000000000000000(0000) GS:ffff88043fc40000(0000) knlGS:0000000000000000
[17596.853928] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[17596.853929] CR2: 00007fd8449a7000 CR3: 00000000019f2000 CR4: 00000000000407e0
[17596.853932] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[17596.853934] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[17596.853935] Stack:
[17596.853936]  ffffffffc059d3c0 ffff88041be93540 ffff88041329a000 0000000000000000
[17596.853937]  04cdd20102072112 0000000400000000 00000000f389a2ad ffff88042c49a400
[17596.853939]  ffff88042c49a400 ffff88042c49a4c8 ffff88042c49a530 0000000000000000
[17596.853940] Call Trace:
[17596.853949]  [<ffffffffc0580c22>] nfs4_state_manager+0x5f2/0x8c0 [nfsv4]
[17596.853955]  [<ffffffffc0580ef0>] ? nfs4_state_manager+0x8c0/0x8c0 [nfsv4]
[17596.853961]  [<ffffffffc0580f0f>] nfs4_run_state_manager+0x1f/0x40 [nfsv4]
[17596.853964]  [<ffffffff810b098f>] kthread+0xcf/0xe0
[17596.853966]  [<ffffffff810b08c0>] ? insert_kthread_work+0x40/0x40
[17596.853970]  [<ffffffff816b4f18>] ret_from_fork+0x58/0x90
[17596.853972]  [<ffffffff810b08c0>] ? insert_kthread_work+0x40/0x40
[17596.853972] Code: 24 10 4c 8b 7c 24 10 49 39 df 75 1b e9 e8 00 00 00 49 8b 07 48 89 44 24 10 4c 8b 7c 24 10 49 39 df 0f 84 d2 00 00 00 49 8b 47 48 <a8> 10 75 e2 49 8b 47 48 a8 40 74 da 49 8b be 70 03 00 00 e8 8e