[PATCHv2 1/3] nfsiostat: Add error counts to output when RPC iostats version >= 1.1

[Dave Wysochanski <dwysocha@redhat.com>]

With RPC iostats 1.1 there is a new metric which counts the RPCs
completing with errors (tk_status < 0).  Add these to the output at
the end of the line.  This increases the length of an output line
to 136 columns from 120, but keeps consistent format and spacing:

read:              ops/s            kB/s           kB/op         retrans    avg RTT (ms)    avg exe (ms)  avg queue (ms)          errors
                   0.000           0.106         512.316        0 (0.0%)          17.500          17.500           0.000        0 (0.0%)
write:             ops/s            kB/s           kB/op         retrans    avg RTT (ms)    avg exe (ms)  avg queue (ms)          errors
                   0.001           0.476         512.398        0 (0.0%)           1.667           5.778           3.889       1 (11.1%)

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
 tools/nfs-iostat/nfs-iostat.py | 15 +++++++++++++--
 tools/nfs-iostat/nfsiostat.man |  8 ++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)
 mode change 100644 => 100755 tools/nfs-iostat/nfs-iostat.py

diff --git a/tools/nfs-iostat/nfs-iostat.py b/tools/nfs-iostat/nfs-iostat.py
old mode 100644
new mode 100755
index dec0e861..ef840efe
--- a/tools/nfs-iostat/nfs-iostat.py
+++ b/tools/nfs-iostat/nfs-iostat.py
@@ -329,6 +329,8 @@ class DeviceData:
         queued_for = float(rpc_stats[5])
         rtt = float(rpc_stats[6])
         exe = float(rpc_stats[7])
+        if self.__rpc_data['statsvers'] >= 1.1:
+            errs = float(rpc_stats[8])
 
         # prevent floating point exceptions
         if ops != 0:
@@ -337,6 +339,8 @@ class DeviceData:
             rtt_per_op = rtt / ops
             exe_per_op = exe / ops
             queued_for_per_op = queued_for / ops
+            if self.__rpc_data['statsvers'] >= 1.1:
+                errs_percent = (errs * 100) / ops
         else:
             kb_per_op = 0.0
             retrans_percent = 0.0
@@ -352,7 +356,10 @@ class DeviceData:
         print(format('retrans', '>16s'), end='')
         print(format('avg RTT (ms)', '>16s'), end='')
         print(format('avg exe (ms)', '>16s'), end='')
-        print(format('avg queue (ms)', '>16s'))
+        print(format('avg queue (ms)', '>16s'), end='')
+        if self.__rpc_data['statsvers'] >= 1.1:
+            print(format('errors', '>16s'), end='')
+        print()
 
         print(format((ops / sample_time), '>24.3f'), end='')
         print(format((kilobytes / sample_time), '>16.3f'), end='')
@@ -361,7 +368,11 @@ class DeviceData:
         print(format(retransmits, '>16'), end='')
         print(format(rtt_per_op, '>16.3f'), end='')
         print(format(exe_per_op, '>16.3f'), end='')
-        print(format(queued_for_per_op, '>16.3f'))
+        print(format(queued_for_per_op, '>16.3f'), end='')
+        if self.__rpc_data['statsvers'] >= 1.1:
+            errors = '{0:>10.0f} ({1:>3.1f}%)'.format(errs, errs_percent).strip()
+            print(format(errors, '>16'), end='')
+        print()
 
     def ops(self, sample_time):
         sends = float(self.__rpc_data['rpcsends'])
diff --git a/tools/nfs-iostat/nfsiostat.man b/tools/nfs-iostat/nfsiostat.man
index 9ae94c5f..940c0431 100644
--- a/tools/nfs-iostat/nfsiostat.man
+++ b/tools/nfs-iostat/nfsiostat.man
@@ -97,6 +97,14 @@ This is the duration from the time the NFS client created the RPC request task t
 .RE
 .RE
 .RE
+.RS 8
+- \fBerrors\fR
+.RS
+This is the number of operations that completed with an error status (status < 0).  This count is only available on kernels with RPC iostats version 1.1 or above.
+.RS
+.RE
+.RE
+.RE
 .TP
 Note that if an interval is used as argument to \fBnfsiostat\fR, then the diffrence from previous interval will be displayed, otherwise the results will be from the time that the share was mounted.
 
-- 
2.20.1