[PATCH] nfsiostat/mountstats: Drop autofs entries before calling compare_iostats()

["Kenneth D'souza" <kdsouza@xxxxxxxxxx>]

nfsiostat/mountstats can fail with below KeyError when old stat and new stat
data go out of sync.

$ mountstats iostat 1 3

Traceback (most recent call last):
  File "/usr/sbin/mountstats", line 1092, in <module>
    res = main()
  File "/usr/sbin/mountstats", line 1081, in main
    return args.func(args)
  File "/usr/sbin/mountstats", line 965, in iostat_command
    print_iostat_summary(old_mountstats, mountstats, devices, sample_time)
  File "/usr/sbin/mountstats", line 920, in print_iostat_summary
    diff_stats = stats.compare_iostats(old_stats)
  File "/usr/sbin/mountstats", line 528, in compare_iostats
    if old_stats.__nfs_data['age'] > self.__nfs_data['age']:
KeyError: 'age'

Steps to Reproduce:

1> Add autofs mounts in /etc/fstab controlled via systemd.

nfs-server:/test1 /mnt1 nfs noauto,x-systemd.idle-timeout=2,x-systemd.automount 0 0
nfs-server:/test2 /mnt2 nfs noauto,x-systemd.idle-timeout=2,x-systemd.automount 0 0
nfs-server:/test3 /mnt3 nfs noauto,x-systemd.idle-timeout=2,x-systemd.automount 0 0

2> Trigger the mounts via below command:

$ while :; do date; ls -lR /mnt* 2>&1 >/dev/null; sleep 3; done

3> On other terminal run nfsiostat or mountstats command:

$ mountstats iostat 1 3
$ nfsiostat 1 3

Frequent mount and umount can cause autofs entries to be processed in compare_iostats.
We need to filter the devices list and drop autofs entries to fix the issue.
This way we pass only nfs mounts and not autofs entries.

Signed-off-by: Kenneth D'souza <kdsouza@xxxxxxxxxx>
---
 tools/mountstats/mountstats.py | 9 +++++----
 tools/nfs-iostat/nfs-iostat.py | 5 ++++-
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/tools/mountstats/mountstats.py b/tools/mountstats/mountstats.py
index 00adc96b..25e92a19 100755
--- a/tools/mountstats/mountstats.py
+++ b/tools/mountstats/mountstats.py
@@ -953,10 +953,11 @@ def print_iostat_summary(old, new, devices, time):
         if not old or device not in old:
             stats.display_iostats(time)
         else:
-            old_stats = DeviceData()
-            old_stats.parse_stats(old[device])
-            diff_stats = stats.compare_iostats(old_stats)
-            diff_stats.display_iostats(time)
+            if ("fstype autofs" not in str(old[device])) and ("fstype autofs" not in str(new[device])):
+                old_stats = DeviceData()
+                old_stats.parse_stats(old[device])
+                diff_stats = stats.compare_iostats(old_stats)
+                diff_stats.display_iostats(time)
 
 def iostat_command(args):
     """iostat-like command for NFS mount points
diff --git a/tools/nfs-iostat/nfs-iostat.py b/tools/nfs-iostat/nfs-iostat.py
index 4f5e8a66..1df74ba8 100755
--- a/tools/nfs-iostat/nfs-iostat.py
+++ b/tools/nfs-iostat/nfs-iostat.py
@@ -470,10 +470,13 @@ def parse_stats_file(filename):
 def print_iostat_summary(old, new, devices, time, options):
     stats = {}
     diff_stats = {}
+    devicelist = []
     if old:
         # Trim device list to only include intersection of old and new data,
         # this addresses umounts due to autofs mountpoints
-        devicelist = [x for x in old if x in devices]
+        for device in devices:
+            if "fstype autofs" not in str(old[device]):
+                devicelist.append(device)
     else:
         devicelist = devices
 
-- 
2.21.3