Fix fio silently dropping log entries when using log_compression

This fixes issue 1457: https://github.com/axboe/fio/issues/1457

The fix is to just add a workqueue_flush to iolog_flush so that any log
chunks being compressed in the workqueue get flushed before we compress
and write the entries in the current active logs. Without this, log
entries in the workqueue can be omitted or be written out of order.

We also add a new test that ensures the log file has the right number of
entries in the correct order when using log_compression, both with and
without the store_log_compressed option.

There is still some cleanup to do with respect to the current
documentation and comments for the log_compression option, as it does
not affect the size of chunks, but instead is effectively a boolean that
controls whether chunks are compressed and removed. I'll leave that for
a separate PR.

Signed-off-by: Nick Neumann <nick@pcpartpicker.com>

diff --git a/iolog.c b/iolog.c
index 37e799a13ca6c9eb11f9d50f4f2f1faa43010a5f..41d3e4735036a2a23c7aa157934f5188f39a03b7 100644 (file)
--- a/iolog.c
+++ b/iolog.c
@@ -1574,14 +1574,14 @@ void iolog_compress_exit(struct thread_data *td)
  * Queue work item to compress the existing log entries. We reset the
  * current log to a small size, and reference the existing log in the
  * data that we queue for compression. Once compression has been done,
- * this old log is freed. If called with finish == true, will not return
- * until the log compression has completed, and will flush all previous
- * logs too
+ * this old log is freed. Will not return until the log compression
+ * has completed, and will flush all previous logs too
  */
 static int iolog_flush(struct io_log *log)
 {
        struct iolog_flush_data *data;
 
+       workqueue_flush(&log->td->log_compress_wq);
        data = malloc(sizeof(*data));
        if (!data)
                return 1;

diff --git a/t/log_compression.py b/t/log_compression.py
new file mode 100755 (executable)
index 0000000..94c92db
--- /dev/null
+++ b/t/log_compression.py
@@ -0,0 +1,121 @@
+#!/usr/bin/env python3
+#
+# log_compression.py
+#
+# Test log_compression and log_store_compressed. Uses null ioengine.
+# Previous bugs have caused output in per I/O log files to be missing
+# and/or out of order
+#
+# Expected result: 8000 log entries, offset starting at 0 and increasing by bs
+# Buggy result: Log entries out of order (usually without log_store_compressed)
+# and/or missing log entries (usually with log_store_compressed)
+#
+# USAGE
+# python log_compression.py [-f fio-executable]
+#
+# EXAMPLES
+# python t/log_compression.py
+# python t/log_compression.py -f ./fio
+#
+# REQUIREMENTS
+# Python 3.5+
+#
+# ===TEST MATRIX===
+#
+# With log_compression=10K
+# With log_store_compressed=1 and log_compression=10K
+
+import os
+import sys
+import platform
+import argparse
+import subprocess
+
+
+def parse_args():
+    """Parse command-line arguments."""
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-f', '--fio',
+                        help='path to fio executable (e.g., ./fio)')
+    return parser.parse_args()
+
+
+def run_fio(fio,log_store_compressed):
+    fio_args = [
+        '--name=job',
+        '--ioengine=null',
+        '--filesize=1000M',
+        '--bs=128K',
+        '--rw=write',
+        '--iodepth=1',
+        '--write_bw_log=test',
+        '--per_job_logs=0',
+        '--log_offset=1',
+        '--log_compression=10K',
+        ]
+    if log_store_compressed:
+        fio_args.append('--log_store_compressed=1')
+
+    subprocess.check_output([fio] + fio_args)
+
+    if log_store_compressed:
+        fio_inflate_args = [
+            '--inflate-log=test_bw.log.fz'
+            ]
+        with open('test_bw.from_fz.log','wt') as f:
+            subprocess.check_call([fio]+fio_inflate_args,stdout=f)
+
+def check_log_file(log_store_compressed):
+    filename = 'test_bw.from_fz.log' if log_store_compressed else 'test_bw.log'
+    with open(filename,'rt') as f:
+        file_data = f.read()
+    log_lines = [x for x in file_data.split('\n') if len(x.strip())!=0]
+    log_ios = len(log_lines)
+
+    filesize = 1000*1024*1024
+    bs = 128*1024
+    ios = filesize//bs
+    if log_ios!=ios:
+        print('wrong number of ios ({}) in log; should be {}'.format(log_ios,ios))
+        return False
+
+    expected_offset = 0
+    for line_number,line in enumerate(log_lines):
+        log_offset = int(line.split(',')[4])
+        if log_offset != expected_offset:
+            print('wrong offset ({}) for io number {} in log; should be {}'.format(
+                log_offset, line_number, expected_offset))
+            return False
+        expected_offset += bs
+    return True
+
+def main():
+    """Entry point for this script."""
+    args = parse_args()
+    if args.fio:
+        fio_path = args.fio
+    else:
+        fio_path = os.path.join(os.path.dirname(__file__), '../fio')
+        if not os.path.exists(fio_path):
+            fio_path = 'fio'
+    print("fio path is", fio_path)
+
+    passed_count = 0
+    failed_count = 0
+    for log_store_compressed in [False, True]:
+        run_fio(fio_path, log_store_compressed)
+        passed = check_log_file(log_store_compressed)
+        print('Test with log_store_compressed={} {}'.format(log_store_compressed,
+            'PASSED' if passed else 'FAILED'))
+        if passed:
+            passed_count+=1
+        else:
+            failed_count+=1
+
+    print('{} tests passed, {} failed'.format(passed_count, failed_count))
+
+    sys.exit(failed_count)
+
+if __name__ == '__main__':
+    main()
+

diff --git a/t/run-fio-tests.py b/t/run-fio-tests.py
index 47823761361b9dc07b646efecc9311fd16a1cc76..e72fa2a01cb1e99e51ec9918b0560ec1a1ae1f1e 100755 (executable)
--- a/t/run-fio-tests.py
+++ b/t/run-fio-tests.py
@@ -1124,6 +1124,14 @@ TEST_LIST = [
         'success':          SUCCESS_DEFAULT,
         'requirements':     [],
     },
+    {
+        'test_id':          1012,
+        'test_class':       FioExeTest,
+        'exe':              't/log_compression.py',
+        'parameters':       ['-f', '{fio_path}'],
+        'success':          SUCCESS_DEFAULT,
+        'requirements':     [],
+    },
 ]