Workunits : fs/misc/: check if cache is used in direct IO

Signed-off-by: Yan, Zheng <zyan@redhat.com>

qa/workunits/fs/misc/direct_io.py

@@ -0,0 +1,47 @@
+#!/usr/bin/python
+
+import os
+import mmap
+import subprocess
+import json
+
+def get_data_pool():
+    cmd = ['ceph', 'fs', 'ls', '--format=json-pretty']
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    out = proc.communicate()[0]
+    return json.loads(out)[0]['data_pools'][0]
+
+def main():
+    fd = os.open("testfile", os.O_RDWR | os.O_CREAT | os.O_TRUNC | os.O_DIRECT, 0644)
+
+    ino = os.fstat(fd).st_ino
+    obj_name = "{ino:x}.00000000".format(ino=ino)
+    pool_name = get_data_pool()
+
+    buf = mmap.mmap(-1, 1);
+    buf.write('1');
+    os.write(fd, buf);
+
+    proc = subprocess.Popen(['rados', '-p', pool_name, 'get', obj_name, 'tmpfile'])
+    proc.wait();
+
+    with open('tmpfile', 'r') as tmpf:
+        out = tmpf.read()
+        if out != '1':
+            raise RuntimeError("data were not written to object store directly")
+
+    with open('tmpfile', 'w') as tmpf:
+        tmpf.write('2')
+
+    proc = subprocess.Popen(['rados', '-p', pool_name, 'put', obj_name, 'tmpfile'])
+    proc.wait();
+
+    os.lseek(fd, 0, os.SEEK_SET)
+    out = os.read(fd, 1);
+    if out != '2':
+        raise RuntimeError("data were not directly read from object store")
+
+    os.close(fd);
+    print 'ok'
+
+main()