From 0aca27d2fcb17e4e5b5ef339b2d1d011d52dbd6c Mon Sep 17 00:00:00 2001
From: dparmar18 <dparmar@redhat.com>
Date: Mon, 23 May 2022 14:45:40 +0530
Subject: [PATCH] qa/cephfs: fallback to older way of get_op_read_count

Fixes: https://tracker.ceph.com/issues/55538

Signed-off-by: Dhairya Parmar <dparmar@redhat.com>
---
 qa/tasks/cephfs/kernel_mount.py   | 26 +++++++++++++++++++++-----
 qa/tasks/cephfs/test_readahead.py |  3 +--
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/qa/tasks/cephfs/kernel_mount.py b/qa/tasks/cephfs/kernel_mount.py
index 8d11b01028c..22eb8d95114 100644
--- a/qa/tasks/cephfs/kernel_mount.py
+++ b/qa/tasks/cephfs/kernel_mount.py
@@ -1,3 +1,4 @@
+import errno
 import json
 import logging
 import os
@@ -349,8 +350,23 @@ echo '{fdata}' | sudo tee /sys/kernel/debug/dynamic_debug/control
         return epoch, barrier
 
     def get_op_read_count(self):
-        buf = self.read_debug_file("metrics/size")
-        if buf is None:
-            return 0
-        else:
-            return int(re.findall(r'read.*', buf)[0].split()[1])
+        stdout = StringIO()
+        stderr = StringIO()
+        try:
+            path = os.path.join(self._get_debug_dir(), "metrics/size")
+            self.run_shell(f"sudo stat {path}", stdout=stdout,
+                           stderr=stderr, cwd=None)
+            buf = self.read_debug_file("metrics/size")
+        except CommandFailedError:
+            if 'no such file or directory' in stderr.getvalue().lower() \
+                    or 'not a directory' in stderr.getvalue().lower():
+                try:
+                    path = os.path.join(self._get_debug_dir(), "metrics")
+                    self.run_shell(f"sudo stat {path}", stdout=stdout,
+                                   stderr=stderr, cwd=None)
+                    buf = self.read_debug_file("metrics")
+                except CommandFailedError:
+                    return errno.ENOENT
+            else:
+                return 0
+        return int(re.findall(r'read.*', buf)[0].split()[1])
diff --git a/qa/tasks/cephfs/test_readahead.py b/qa/tasks/cephfs/test_readahead.py
index b1484ab0713..7e6270f035d 100644
--- a/qa/tasks/cephfs/test_readahead.py
+++ b/qa/tasks/cephfs/test_readahead.py
@@ -16,8 +16,7 @@ class TestReadahead(CephFSTestCase):
         initial_op_read = self.mount_a.get_op_read_count()
         self.mount_a.run_shell(["dd", "if=foo", "of=/dev/null", "bs=128k", "count=32"])
         op_read = self.mount_a.get_op_read_count()
-
-        assert op_read >= initial_op_read
+        self.assertGreaterEqual(op_read, initial_op_read)
         op_read -= initial_op_read
         log.info("read operations: {0}".format(op_read))