Re: [PATCH v2 8/9] aio: move aio sysctl to aio.c

From: Jan Kara
Date: Wed Nov 24 2021 - 04:32:48 EST


On Tue 23-11-21 12:23:46, Luis Chamberlain wrote:
> From: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
>
> The kernel/sysctl.c is a kitchen sink where everyone leaves
> their dirty dishes, this makes it very difficult to maintain.
>
> To help with this maintenance let's start by moving sysctls to
> places where they actually belong. The proc sysctl maintainers
> do not want to know what sysctl knobs you wish to add for your own
> piece of code, we just care about the core logic.
>
> Move aio sysctl to aio.c and use the new register_sysctl_init() to
> register the sysctl interface for aio.
>
> Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
> [mcgrof: adjust commit log to justify the move]
> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>

Makes sense. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/aio.c | 31 +++++++++++++++++++++++++++++--
> include/linux/aio.h | 4 ----
> kernel/sysctl.c | 17 -----------------
> 3 files changed, 29 insertions(+), 23 deletions(-)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index 9c81cf611d65..83ef2341e73f 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -219,9 +219,35 @@ struct aio_kiocb {
>
> /*------ sysctl variables----*/
> static DEFINE_SPINLOCK(aio_nr_lock);
> -unsigned long aio_nr; /* current system wide number of aio requests */
> -unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
> +static unsigned long aio_nr; /* current system wide number of aio requests */
> +static unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
> /*----end sysctl variables---*/
> +#ifdef CONFIG_SYSCTL
> +static struct ctl_table aio_sysctls[] = {
> + {
> + .procname = "aio-nr",
> + .data = &aio_nr,
> + .maxlen = sizeof(aio_nr),
> + .mode = 0444,
> + .proc_handler = proc_doulongvec_minmax,
> + },
> + {
> + .procname = "aio-max-nr",
> + .data = &aio_max_nr,
> + .maxlen = sizeof(aio_max_nr),
> + .mode = 0644,
> + .proc_handler = proc_doulongvec_minmax,
> + },
> + {}
> +};
> +
> +static void __init aio_sysctl_init(void)
> +{
> + register_sysctl_init("fs", aio_sysctls);
> +}
> +#else
> +#define aio_sysctl_init() do { } while (0)
> +#endif
>
> static struct kmem_cache *kiocb_cachep;
> static struct kmem_cache *kioctx_cachep;
> @@ -274,6 +300,7 @@ static int __init aio_setup(void)
>
> kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
> kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
> + aio_sysctl_init();
> return 0;
> }
> __initcall(aio_setup);
> diff --git a/include/linux/aio.h b/include/linux/aio.h
> index b83e68dd006f..86892a4fe7c8 100644
> --- a/include/linux/aio.h
> +++ b/include/linux/aio.h
> @@ -20,8 +20,4 @@ static inline void kiocb_set_cancel_fn(struct kiocb *req,
> kiocb_cancel_fn *cancel) { }
> #endif /* CONFIG_AIO */
>
> -/* for sysctl: */
> -extern unsigned long aio_nr;
> -extern unsigned long aio_max_nr;
> -
> #endif /* __LINUX__AIO_H */
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 597ab5ad4879..20326d67b814 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -20,7 +20,6 @@
> */
>
> #include <linux/module.h>
> -#include <linux/aio.h>
> #include <linux/mm.h>
> #include <linux/swap.h>
> #include <linux/slab.h>
> @@ -3110,22 +3109,6 @@ static struct ctl_table fs_table[] = {
> .proc_handler = proc_dointvec,
> },
> #endif
> -#ifdef CONFIG_AIO
> - {
> - .procname = "aio-nr",
> - .data = &aio_nr,
> - .maxlen = sizeof(aio_nr),
> - .mode = 0444,
> - .proc_handler = proc_doulongvec_minmax,
> - },
> - {
> - .procname = "aio-max-nr",
> - .data = &aio_max_nr,
> - .maxlen = sizeof(aio_max_nr),
> - .mode = 0644,
> - .proc_handler = proc_doulongvec_minmax,
> - },
> -#endif /* CONFIG_AIO */
> #ifdef CONFIG_INOTIFY_USER
> {
> .procname = "inotify",
> --
> 2.33.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR