On Fri, 15 Sep 2023, Babu Moger wrote:
> rdt_enable_ctx() enables the features provided during resctrl mount.
>
> Additions to rdt_enable_ctx() are required to also modify error paths
> of rdt_enable_ctx() callers to ensure correct unwinding if errors
> are encountered after calling rdt_enable_ctx(). This is error prone.
>
> Introduce rdt_disable_ctx() to refactor the error unwinding of
> rdt_enable_ctx() to simplify future additions. This also simplifies
> cleanup in rdt_kill_sb().
>
> Remove cdp_disable_all() as it is not used anymore after the refactor.
>
> Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 53 ++++++++++++++++----------
> 1 file changed, 32 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 35945b4bf196..3ea874c80c22 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -2290,14 +2290,6 @@ int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable)
> return 0;
> }
>
> -static void cdp_disable_all(void)
> -{
> - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
> - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
> - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
> - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
> -}
> -
> /*
> * We don't allow rdtgroup directories to be created anywhere
> * except the root directory. Thus when looking for the rdtgroup
> @@ -2377,19 +2369,42 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
> struct rdtgroup *prgrp,
> struct kernfs_node **mon_data_kn);
>
> +static void rdt_disable_ctx(void)
> +{
> + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
> + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
> + set_mba_sc(false);
> +}
> +
> static int rdt_enable_ctx(struct rdt_fs_context *ctx)
> {
> int ret = 0;
>
> - if (ctx->enable_cdpl2)
> + if (ctx->enable_cdpl2) {
> ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true);
> + if (ret)
> + goto out_done;
> + }
>
> - if (!ret && ctx->enable_cdpl3)
> + if (ctx->enable_cdpl3) {
> ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
> + if (ret)
> + goto out_cdpl2;
> + }
>
> - if (!ret && ctx->enable_mba_mbps)
> + if (ctx->enable_mba_mbps) {
> ret = set_mba_sc(true);
> + if (ret)
> + goto out_cdpl3;
> + }
> +
> + return 0;
>
> +out_cdpl3:
> + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
> +out_cdpl2:
> + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
> +out_done:
> return ret;
> }
>
> @@ -2497,13 +2512,13 @@ static int rdt_get_tree(struct fs_context *fc)
> }
>
> ret = rdt_enable_ctx(ctx);
> - if (ret < 0)
> - goto out_cdp;
> + if (ret)
> + goto out;
>
> ret = schemata_list_create();
> if (ret) {
> schemata_list_destroy();
> - goto out_mba;
> + goto out_ctx;
> }
>
> closid_init();
> @@ -2562,11 +2577,8 @@ static int rdt_get_tree(struct fs_context *fc)
> kernfs_remove(kn_info);
> out_schemata_free:
> schemata_list_destroy();
> -out_mba:
> - if (ctx->enable_mba_mbps)
> - set_mba_sc(false);
> -out_cdp:
> - cdp_disable_all();
> +out_ctx:
> + rdt_disable_ctx();
> out:
> rdt_last_cmd_clear();
> mutex_unlock(&rdtgroup_mutex);
> @@ -2798,12 +2810,11 @@ static void rdt_kill_sb(struct super_block *sb)
> cpus_read_lock();
> mutex_lock(&rdtgroup_mutex);
>
> - set_mba_sc(false);
> + rdt_disable_ctx();
>
> /*Put everything back to default values. */
> for_each_alloc_capable_rdt_resource(r)
> reset_all_ctrls(r);
> - cdp_disable_all();
> rmdir_all_sub();
> rdt_pseudo_lock_release();
> rdtgroup_default.mode = RDT_MODE_SHAREABLE;
>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
--
i.
