seq_file: add helper macro to define attribute for rw file

Patch series "Add helper macro DEFINE_SHOW_STORE_ATTRIBUTE() at
seq_file.c", v6.

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

So we add this helper macro to reduce duplicated code.

This patch (of 3):

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

So we add DEFINE_SHOW_STORE_ATTRIBUTE() helper to reduce duplicated code.

Link: https://lkml.kernel.org/r/20230905024835.43219-1-yangxingui@huawei.com
Link: https://lkml.kernel.org/r/20230905024835.43219-2-yangxingui@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Co-developed-by: Xingui Yang <yangxingui@huawei.com>
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Cc: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 386ab580b839b66518ed33cda02fd3c201b064d6..234bcdb1fba459916635067154bedd17d8cfd423 100644 (file)
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -207,6 +207,21 @@ static const struct file_operations __name ## _fops = {                    \
        .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,                               \
+}
+
 #define DEFINE_PROC_SHOW_ATTRIBUTE(__name)                             \
 static int __name ## _open(struct inode *inode, struct file *file)     \
 {                                                                      \