[PATCH v2 1/5] seq_file: Introduce DEFINE_SHOW_STORE_ATTRIBUTE() helper macro

From: Luo Jiaxing
Date: Fri Oct 30 2020 - 04:50:46 EST


We already own DEFINE_SHOW_ATTRIBUTE() helper macro for defining attribute
for read-only file, but we found many of drivers want a helper marco for
read-write file too.

So we try to make one to decrease code duplication.

Signed-off-by: Luo Jiaxing <luojiaxing@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 813614d..8a474c8 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -191,6 +191,21 @@ static const struct proc_ops __name ## _proc_ops = { \
.proc_release = single_release, \
}

+#define DEFINE_SHOW_STORE_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 ## _write, \
+ .llseek = seq_lseek, \
+ .release = single_release, \
+}
+
static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
{
#ifdef CONFIG_USER_NS
--
2.7.4