Re: [PATCH v2 4/8] ocfs2: simplify subdirectory registration with register_sysctl()

From: Jan Kara
Date: Wed Nov 24 2021 - 04:49:10 EST


On Tue 23-11-21 12:24:18, Luis Chamberlain wrote:
> There is no need to user boiler plate code to specify a set of base
> directories we're going to stuff sysctls under. Simplify this by using
> register_sysctl() and specifying the directory path directly.
>
> // pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH

Heh, nice example of using Coccinelle. The result looks good. Feel free to
add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza


>
> @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,
> - },
> - { }
> -};
>
> @initialize:python@
> @@
>
> def make_my_fresh_expression(s1, s2):
> return '"' + s1.strip('"') + "/" + s2.strip('"') + '"'
>
> @r3 depends on c1 && c2 && c3@
> expression c1.E1;
> identifier c1.sysctls;
> expression c2.E2;
> identifier c2.base;
> identifier c3.header;
> fresh identifier E3 = script:python(E2, E1) { make_my_fresh_expression(E2, E1) };
> @@
>
> header =
> -register_sysctl_table(base);
> +register_sysctl(E3, sysctls);
>
> Generated-by: Coccinelle SmPL
> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> ---
> fs/ocfs2/stackglue.c | 25 +------------------------
> 1 file changed, 1 insertion(+), 24 deletions(-)
>
> diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
> index 16f1bfc407f2..731558a6f27d 100644
> --- a/fs/ocfs2/stackglue.c
> +++ b/fs/ocfs2/stackglue.c
> @@ -672,31 +672,8 @@ static struct ctl_table ocfs2_mod_table[] = {
> { }
> };
>
> -static struct ctl_table ocfs2_kern_table[] = {
> - {
> - .procname = "ocfs2",
> - .data = NULL,
> - .maxlen = 0,
> - .mode = 0555,
> - .child = ocfs2_mod_table
> - },
> - { }
> -};
> -
> -static struct ctl_table ocfs2_root_table[] = {
> - {
> - .procname = "fs",
> - .data = NULL,
> - .maxlen = 0,
> - .mode = 0555,
> - .child = ocfs2_kern_table
> - },
> - { }
> -};
> -
> static struct ctl_table_header *ocfs2_table_header;
>
> -
> /*
> * Initialization
> */
> @@ -705,7 +682,7 @@ static int __init ocfs2_stack_glue_init(void)
> {
> strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);
>
> - ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
> + ocfs2_table_header = register_sysctl("fs/ocfs2", ocfs2_mod_table);
> if (!ocfs2_table_header) {
> printk(KERN_ERR
> "ocfs2 stack glue: unable to register sysctl\n");
> --
> 2.33.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR