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From:   Chen Zhou <chenzhou10@huawei.com>
To:     <tj@kernel.org>, <lizefan@huawei.com>, <hannes@cmpxchg.org>
CC:     <cgroups@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <chenzhou10@huawei.com>
Subject: [PATCH v2] cgroup-v1: add disabled controller check in cgroup1_parse_param()
Date:   Fri, 18 Dec 2020 14:17:55 +0800
Message-ID: <20201218061755.121205-1-chenzhou10@huawei.com>
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Precedence: bulk

When mounting a cgroup hierarchy with disabled controller in cgroup v1,
all available controllers will be attached.

Add disabled controller check in cgroup1_parse_param() and return directly
if the specified controller is disabled.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
---
Changes in v2:
- Fix line over 80 characters warning.
---
 kernel/cgroup/cgroup-v1.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 191c329e482a..5190c42fea8b 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -915,6 +915,9 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		for_each_subsys(ss, i) {
 			if (strcmp(param->key, ss->legacy_name))
 				continue;
+			if (!cgroup_ssid_enabled(i) || cgroup1_ssid_disabled(i))
+				return invalfc(fc, "Disabled controller '%s'",
+					       param->key);
 			ctx->subsys_mask |= (1 << i);
 			return 0;
 		}
-- 
2.20.1