[PATCH v1] mountstats: handle KeyError in display_raw_stats

[Rohan Sable <rsable@redhat.com>]

While printing Nfsv4ops from older /proc/self/mountstats
e.g. in 2.6.32-754.el6.x86_64 from RHEL 6.10,
it will not have all the Keys present leading to a KeyError
like below :

Traceback (most recent call last):
  File "nfs-utils/tools/mountstats/mountstats.py", line 1131, in <module>
    res = main()
  File "nfs-utils/tools/mountstats/mountstats.py", line 1120, in main
    return args.func(args)
  File "nfs-utils/tools/mountstats/mountstats.py", line 860, in mountstats_command
    print_mountstats(stats, args.nfs_only, args.rpc_only, args.raw, args.xprt_only)
  File "nfs-utils/tools/mountstats/mountstats.py", line 813, in print_mountstats
    stats.display_raw_stats()
  File "nfs-utils/tools/mountstats/mountstats.py", line 381, in display_raw_stats
    print('\t%12s: %s' % (op, " ".join(str(x) for x in self.__rpc_data[op])))
KeyError: 'FSID_PRESENT'

Signed-off-by: Rohan Sable <rsable@redhat.com>
---
 tools/mountstats/mountstats.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/mountstats/mountstats.py b/tools/mountstats/mountstats.py
index 25e92a19..23876fc4 100755
--- a/tools/mountstats/mountstats.py
+++ b/tools/mountstats/mountstats.py
@@ -378,7 +378,10 @@ class DeviceData:
                 print('\t%12s: %s' % (op, " ".join(str(x) for x in self.__rpc_data[op])))
         elif vers == '4':
             for op in Nfsv4ops:
-                print('\t%12s: %s' % (op, " ".join(str(x) for x in self.__rpc_data[op])))
+                try:
+                    print('\t%12s: %s' % (op, " ".join(str(x) for x in self.__rpc_data[op])))
+                except KeyError:
+                    continue
         else:
             print('\tnot implemented for version %d' % vers)
         print()
-- 
2.26.2