[Devel] [PATCH rh7] ve: fs -- Export fs.aio-nr and fs.aio-max-nr via ve cgroup

[Konstantin Khorenko]

Kirill, your input is required here.

Do we need to migrate both fs.aio-(max)-nr or it's enough to migrate fs.aio-max-nr?

--
Best regards,

Konstantin Khorenko,
Virtuozzo Linux Kernel Team

On 04/09/2016 12:49 PM, Cyrill Gorcunov wrote:
> This members represents fs.aio-(max)-nr sysctl entries.
> While fs.aio-max-nr can be adjusted from inside of ve with
> traditional sysctl utility the @aio-nr is read only so we
> need an interface for its c/r.
>
> Moreover I think being able to c/r from libvzctl script is
> better in terms of keeping c/r work in one place, so instead
> of handling fs.aio-max-nr with sysctl utility from inside of ve
> context, I do it via scripts and for this sake fs.aio-max-nr
> is exported via cgroup api.
>
> https://jira.sw.ru/browse/PSBM-40690
>
> Signed-off-by: Cyrill Gorcunov <gorcunov at virtuozzo.com>
> CC: Vladimir Davydov <vdavydov at virtuozzo.com>
> CC: Konstantin Khorenko <khorenko at virtuozzo.com>
> ---
>   kernel/ve/ve.c |   29 +++++++++++++++++++++++++++--
>   1 file changed, 27 insertions(+), 2 deletions(-)
>
> Index: linux-pcs7.git/kernel/ve/ve.c
> ===================================================================
> --- linux-pcs7.git.orig/kernel/ve/ve.c
> +++ linux-pcs7.git/kernel/ve/ve.c
> @@ -1180,7 +1180,9 @@ enum {
>   	VE_CF_IPTABLES_MASK,
>   	VE_CF_PSEUDOSUPER,
>   	VE_CF_CLOCK_MONOTONIC,
> -	VE_CF_CLOCK_BOOTBASED
> +	VE_CF_CLOCK_BOOTBASED,
> +	VE_CF_AIO_NR,
> +	VE_CF_AIO_MAX_NR,
>   };
>
>   static int ve_ts_read(struct cgroup *cg, struct cftype *cft, struct seq_file *m)
> @@ -1240,6 +1242,10 @@ static u64 ve_read_u64(struct cgroup *cg
>   #endif
>   	else if (cft->private == VE_CF_PSEUDOSUPER)
>   		return cgroup_ve(cg)->is_pseudosuper;
> +	else if (cft->private == VE_CF_AIO_NR)
> +		return cgroup_ve(cg)->aio_nr;
> +	else if (cft->private == VE_CF_AIO_MAX_NR)
> +		return cgroup_ve(cg)->aio_max_nr;
>   	return 0;
>   }
>
> @@ -1276,7 +1282,8 @@ static int ve_write_u64(struct cgroup *c
>   {
>   	struct ve_struct *ve = cgroup_ve(cg);
>
> -	if (!ve_is_super(get_exec_env()))
> +	if (!ve_is_super(get_exec_env()) &&
> +	    !ve->is_pseudosuper)
>   		return -EPERM;
>
>   	down_write(&ve->op_sem);
> @@ -1291,6 +1298,10 @@ static int ve_write_u64(struct cgroup *c
>   	else if (cft->private == VE_CF_IPTABLES_MASK)
>   		ve->ipt_mask = ve_setup_iptables_mask(value);
>   #endif
> +	else if (cft->private == VE_CF_AIO_NR)
> +		ve->aio_nr = value;
> +	else if (cft->private == VE_CF_AIO_MAX_NR)
> +		ve->aio_max_nr = value;
>   	up_write(&ve->op_sem);
>   	return 0;
>   }
> @@ -1359,6 +1370,20 @@ static struct cftype ve_cftypes[] = {
>   		.write_string		= ve_ts_write,
>   		.private		= VE_CF_CLOCK_BOOTBASED,
>   	},
> +	{
> +		.name			= "aio_nr",
> +		.flags			= CFTYPE_NOT_ON_ROOT,
> +		.read_u64		= ve_read_u64,
> +		.write_u64		= ve_write_u64,
> +		.private		= VE_CF_AIO_NR,
> +	},
> +	{
> +		.name			= "aio_max_nr",
> +		.flags			= CFTYPE_NOT_ON_ROOT,
> +		.read_u64		= ve_read_u64,
> +		.write_u64		= ve_write_u64,
> +		.private		= VE_CF_AIO_MAX_NR,
> +	},
>   	{ }
>   };
>
> .
>