f2fs: add tracepoint for f2fs_issue_flush

This patch adds a tracepoint for f2fs_issue_flush.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

@@ -239,6 +239,9 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
 	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
 	struct flush_cmd cmd;
 
+	trace_f2fs_issue_flush(sbi->sb, test_opt(sbi, NOBARRIER),
+					test_opt(sbi, FLUSH_MERGE));
+
 	if (test_opt(sbi, NOBARRIER))
 		return 0;
 

include/trace/events/f2fs.h

@@ -926,6 +926,30 @@ TRACE_EVENT(f2fs_issue_discard,
 		(unsigned long long)__entry->blkstart,
 		(unsigned long long)__entry->blklen)
 );
+
+TRACE_EVENT(f2fs_issue_flush,
+
+	TP_PROTO(struct super_block *sb, bool nobarrier, bool flush_merge),
+
+	TP_ARGS(sb, nobarrier, flush_merge),
+
+	TP_STRUCT__entry(
+		__field(dev_t,	dev)
+		__field(bool, nobarrier)
+		__field(bool, flush_merge)
+	),
+
+	TP_fast_assign(
+		__entry->dev	= sb->s_dev;
+		__entry->nobarrier = nobarrier;
+		__entry->flush_merge = flush_merge;
+	),
+
+	TP_printk("dev = (%d,%d), %s %s",
+		show_dev(__entry),
+		__entry->nobarrier ? "skip (nobarrier)" : "issue",
+		__entry->flush_merge ? " with flush_merge" : "")
+);
 #endif /* _TRACE_F2FS_H */
 
  /* This part must be outside protection */