[PATCH v7 5/8] x86/resctrl: Unwind the errors inside rdt_enable_ctx()

[Babu Moger]

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.

Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   44 ++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 3010e3a1394d..0805fac04401 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2377,19 +2377,44 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
 			     struct rdtgroup *prgrp,
 			     struct kernfs_node **mon_data_kn);
 
+static void rdt_disable_ctx(struct rdt_fs_context *ctx)
+{
+	if (ctx->enable_cdpl2)
+		resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
+
+	if (ctx->enable_cdpl3)
+		resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
+
+	if (ctx->enable_mba_mbps)
+		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_disable;
+	}
 
-	if (!ret && ctx->enable_cdpl3)
+	if (ctx->enable_cdpl3) {
 		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
+		if (ret)
+			goto out_disable;
+	}
 
-	if (!ret && ctx->enable_mba_mbps)
+	if (ctx->enable_mba_mbps) {
 		ret = set_mba_sc(true);
+		if (ret)
+			goto out_disable;
+	}
+
+	return 0;
 
+out_disable:
+	rdt_disable_ctx(ctx);
 	return ret;
 }
 
@@ -2497,13 +2522,13 @@ 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 +2587,8 @@ 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(ctx);
 out:
 	rdt_last_cmd_clear();
 	mutex_unlock(&rdtgroup_mutex);