[RFC PATCH] seq_file: Introduce DEFINE_RW_ATTRIBUTE() helper macro

[xiubli]

From: Xiubo Li <xiubli@xxxxxxxxxx>

It's time to introduce the DEFINE_RW_ATTRIBUTE() helper macro, this
would be useful for current users, there are many places are doing
the duplicated works. This could decrease code duplication.

Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
 include/linux/seq_file.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 5998e1f4ff06..9e0c10a5aa4a 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -160,6 +160,21 @@ static const struct file_operations __name ## _fops = {			\
 	.release	= single_release,				\
 }
 
+#define DEFINE_RW_ATTRIBUTE(__name)					\
+static int __name ## _open(struct inode *inode, struct file *file)	\
+{									\
+	return single_open(file, __name ## _show, inode->i_private);	\
+}									\
+									\
+static const struct file_operations __name ## _fops = {			\
+	.owner		= THIS_MODULE,					\
+	.open		= __name ## _open,				\
+	.read		= seq_read,					\
+	.write		= __name ## _store,				\
+	.llseek		= seq_lseek,					\
+	.release	= single_release,				\
+}
+
 static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
 {
 #ifdef CONFIG_USER_NS
-- 
2.21.0