[02/13] cdrom: use new sysctl subdir helper register_sysctl_subdir()

Commit Message

Luis Chamberlain May 29, 2020, 7:40 a.m. UTC

This simplifies the code considerably. The following coccinelle
SmPL grammar rule was used to transform this code.

// pycocci sysctl-subdir.cocci drivers/cdrom/cdrom.c

@c1@
expression E1;
identifier subdir, sysctls;
@@

static struct ctl_table subdir[] = {
	{
		.procname = E1,
		.maxlen = 0,
		.mode = 0555,
		.child = sysctls,
	},
	{ }
};

@c2@
identifier c1.subdir;

expression E2;
identifier base;
@@

static struct ctl_table base[] = {
	{
		.procname = E2,
		.maxlen = 0,
		.mode = 0555,
		.child = subdir,
	},
	{ }
};

@c3@
identifier c2.base;
identifier header;
@@

header = register_sysctl_table(base);

@r1 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.subdir, c1.sysctls;
@@

-static struct ctl_table subdir[] = {
-	{
-		.procname = E1,
-		.maxlen = 0,
-		.mode = 0555,
-		.child = sysctls,
-	},
-	{ }
-};

@r2 depends on c1 && c2 && c3@
identifier c1.subdir;

expression c2.E2;
identifier c2.base;
@@
-static struct ctl_table base[] = {
-	{
-		.procname = E2,
-		.maxlen = 0,
-		.mode = 0555,
-		.child = subdir,
-	},
-	{ }
-};

@r3 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.sysctls;
expression c2.E2;
identifier c2.base;
identifier c3.header;
@@

header =
-register_sysctl_table(base);
+register_sysctl_subdir(E2, E1, sysctls);

Generated-by: Coccinelle SmPL
Signed-off-by: Luis Chamberlain <[e-mail]>
---
 drivers/cdrom/cdrom.c | 23 ++---------------------
 1 file changed, 2 insertions(+), 21 deletions(-)

Comments

Eric W. Biederman May 29, 2020, 12:46 p.m. UTC | #1

Luis Chamberlain <[e-mail]> writes:

> This simplifies the code considerably. The following coccinelle

With register_sysctl the code would read:

	cdrom_sysctl_header = register_sysctl("dev/cdrom", cdrom_table);

Please go that direction.  Thank you.

Eric

Patch

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index a0a7ae705de8..3c638f464cef 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -3719,26 +3719,6 @@  static struct ctl_table cdrom_table[] = {
 	{ }
 };
 
-static struct ctl_table cdrom_cdrom_table[] = {
-	{
-		.procname	= "cdrom",
-		.maxlen		= 0,
-		.mode		= 0555,
-		.child		= cdrom_table,
-	},
-	{ }
-};
-
-/* Make sure that /proc/sys/dev is there */
-static struct ctl_table cdrom_root_table[] = {
-	{
-		.procname	= "dev",
-		.maxlen		= 0,
-		.mode		= 0555,
-		.child		= cdrom_cdrom_table,
-	},
-	{ }
-};
 static struct ctl_table_header *cdrom_sysctl_header;
 
 static void cdrom_sysctl_register(void)
@@ -3748,7 +3728,8 @@  static void cdrom_sysctl_register(void)
 	if (!atomic_add_unless(&initialized, 1, 1))
 		return;
 
-	cdrom_sysctl_header = register_sysctl_table(cdrom_root_table);
+	cdrom_sysctl_header = register_sysctl_subdir("dev", "cdrom",
+						     cdrom_table);
 
 	/* set the defaults */
 	cdrom_sysctl_settings.autoclose = autoclose;