Description of problem:
A debugfs mount could include 'No device mounted on /sys/kernel/debug with fstype debugfs' line to '/proc/self/mountstats' file. Present nfsiostat includes the "no device mounted ..." line from /proc/self/mountstats as addition description of the preceding mount point. If the preceding mount point is NFS mountpoint, nfsiostat fails to parse this line eventually.

nfsiostat fails with the below error.
#nfsiostat
:
:Traceback (most recent call last):
:  File "/usr/sbin/nfsiostat", line 634, in <module>
:    iostat_command(prog)
:  File "/usr/sbin/nfsiostat", line 587, in iostat_command
:    devices = list_nfs_mounts(origdevices, mountstats)
:  File "/usr/sbin/nfsiostat", line 490, in list_nfs_mounts
:    stats.parse_stats(descr)
:  File "/usr/sbin/nfsiostat", line 179, in parse_stats
:    self.__parse_rpc_line(words)
:  File "/usr/sbin/nfsiostat", line 163, in __parse_rpc_line
:    self.__rpc_data[op] = [long(word) for word in words[1:]]
:ValueError: invalid literal for long() with base 10: 'device'
:
:Local variables in innermost frame:
:_[1]: []
:self: <__main__.DeviceData instance at 0x128a290>
:word: 'device'
:words: ['no', 'device', 'mounted', 'on', '/sys/kernel/debug', 'with',
'fstype', 'debugfs']   >>>>>>  error.
:op: 'n' 

Version-Release number of selected component (if applicable):
nfs-utils-1.3.0-0.48.el7

How reproducible:
We can manually add the line 'No device mounted on /sys/kernel/debug with fstype debugfs' to a file along with the content of /proc/self/mountstats and make the nfsiostat read this file for parsing.

Steps to Reproduce:
1. cp /proc/self/mountstats /tmp/mountstats
2. update /usr/sbin/nfsiostat to read /tmp/mountstats 
  [change this line - (mountstats = parse_stats_file('/proc/self/mountstats')"]
3. Append 'No device mounted on /sys/kernel/debug..' below a NFS mount
4. run nfsiostat to see the above error

Actual results:
nfsiostat encounters parsing error

Expected results:
show the nfsiostat output without any parsing error

Additional info:
The following commit fixes this - 
nfs-utils]# git log -n 1 0994dc1
commit 0994dc1bb7b348b7bec30f8053841e6d22caf633
Author: Manjunath Patil <manjunath.b.patil>
Date:   Thu Oct 5 10:43:56 2017 -0400

    nfsiostat: avoid parsing "no device mounted ..." line
    
    Present nfsiostat includes the "no device mounted ..." line from
    /proc/self/mountstats as addition description of the preceding mount
    point. If the preceding mount point is NFS mountpoint, nfsiostat fails
    to parse this line eventually. This patch avoids parsing this line.
    
    Signed-off-by: Manjunath Patil <manjunath.b.patil>
    Signed-off-by: Steve Dickson <steved>