Now that Ext4 and f2fs filesystems support encrypted directories and
files, attempts to access those files may return ENOKEY, resulting in
the following WARNING.

Map ENOKEY to nfserr_perm instead of nfserr_io.

[ 1295.411759] ------------[ cut here ]------------
[ 1295.411787] WARNING: CPU: 0 PID: 12786 at fs/nfsd/nfsproc.c:796 nfserrno+0x74/0x80 [nfsd]
[ 1295.411806] nfsd: non-standard errno: -126
[ 1295.411816] Modules linked in: nfsd nfs_acl auth_rpcgss nfsv4 nfs lockd fscache tun bridge stp llc fuse ip_set nfnetlink vmw_vsock_vmci_transport vsock snd_seq_midi snd_seq_midi_event coretemp crct10dif_pclmul crc32_generic crc32_pclmul snd_ens1371 gameport ghash_clmulni_intel snd_ac97_codec f2fs intel_rapl_perf ac97_bus snd_seq ppdev snd_pcm snd_rawmidi snd_timer vmw_balloon snd_seq_device snd joydev soundcore parport_pc parport nfit acpi_cpufreq tpm_tis vmw_vmci tpm_tis_core tpm shpchp i2c_piix4 grace sunrpc xfs libcrc32c vmwgfx drm_kms_helper ttm drm crc32c_intel e1000 mptspi scsi_transport_spi serio_raw mptscsih mptbase ata_generic pata_acpi fjes [last unloaded: nfs_acl]
[ 1295.412522] CPU: 0 PID: 12786 Comm: nfsd Tainted: G        W       4.11.0-rc1+ #521
[ 1295.412959] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
[ 1295.413814] Call Trace:
[ 1295.414252]  dump_stack+0x63/0x86
[ 1295.414666]  __warn+0xcb/0xf0
[ 1295.415087]  warn_slowpath_fmt+0x5f/0x80
[ 1295.415502]  ? put_filp+0x42/0x50
[ 1295.415927]  nfserrno+0x74/0x80 [nfsd]
[ 1295.416339]  nfsd_open+0xd7/0x180 [nfsd]
[ 1295.416746]  nfs4_get_vfs_file+0x367/0x3c0 [nfsd]
[ 1295.417182]  ? security_inode_permission+0x41/0x60
[ 1295.417591]  nfsd4_process_open2+0x9b2/0x1200 [nfsd]
[ 1295.418007]  nfsd4_open+0x481/0x790 [nfsd]
[ 1295.418409]  nfsd4_proc_compound+0x395/0x680 [nfsd]
[ 1295.418812]  nfsd_dispatch+0xb8/0x1f0 [nfsd]
[ 1295.419233]  svc_process_common+0x4d9/0x830 [sunrpc]
[ 1295.419631]  svc_process+0xfe/0x1b0 [sunrpc]
[ 1295.420033]  nfsd+0xe9/0x150 [nfsd]
[ 1295.420420]  kthread+0x101/0x140
[ 1295.420802]  ? nfsd_destroy+0x60/0x60 [nfsd]
[ 1295.421199]  ? kthread_park+0x90/0x90
[ 1295.421598]  ret_from_fork+0x2c/0x40
[ 1295.421996] ---[ end trace 0d5a969cd7852e1f ]---
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>