Re: [PATCH v2 03/14] sysctl: Add ctl_table_size to ctl_table_header

Simon Horman
2023-07-31T18:30:42Z

On Mon, Jul 31, 2023 at 09:17:17AM +0200, Joel Granados wrote:
> The new ctl_table_size element will hold the size of the ctl_table
> arrays contained in the ctl_table_header. This value should eventually
> be passed by the callers to the sysctl register infrastructure. And
> while this commit introduces the variable, it does not set nor use it
> because that requires case by case considerations for each caller.
>
> It provides two important things: (1) A place to put the
> result of the ctl_table array calculation when it gets introduced for
> each caller. And (2) the size that will be used as the additional
> stopping criteria in the list_for_each_table_entry macro (to be added
> when all the callers are migrated)
>
> Signed-off-by: Joel Granados <j.granados@samsung.com>
> ---
> include/linux/sysctl.h | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
> index 59d451f455bf..33252ad58ebe 100644
> --- a/include/linux/sysctl.h
> +++ b/include/linux/sysctl.h
> @@ -159,12 +159,22 @@ struct ctl_node {
> struct ctl_table_header *header;
> };
>
> -/* struct ctl_table_header is used to maintain dynamic lists of
> - struct ctl_table trees. */
> +/**
> + * struct ctl_table_header - maintains dynamic lists of struct ctl_table trees
> + * @ctl_table: pointer to the first element in ctl_table array
> + * @ctl_table_size: number of elements pointed by @ctl_table
> + * @used: The entry will never be touched when equal to 0.
> + * @count: Upped every time something is added to @inodes and downed every time
> + * something is removed from inodes
> + * @nreg: When nreg drops to 0 the ctl_table_header will be unregistered.
> + * @rcu: Delays the freeing of the inode. Introduced with "unfuck proc_sysctl ->d_compare()"
> + *
> + */

Hi Joel,

Please consider also adding kernel doc entries for the other fields of
struct ctl_table_header. According to ./scripts/kernel-doc -none
they are:

unregistering
ctl_table_arg
root
set
parent
node
inodes

> struct ctl_table_header {
> union {
> struct {
> struct ctl_table *ctl_table;
> + int ctl_table_size;
> int used;
> int count;
> int nreg;
> --
> 2.30.2
>