From nobody Tue Feb 10 00:43:41 2026 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C6E921D3F9 for ; Fri, 9 May 2025 07:33:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746776006; cv=none; b=dcNx0pf3THz5VteP1HXIbEqQ2Ct4CA3iH59+JhWmerz5f5TL/NCwC9jwtEgbGsV8BOpe7tMkZQGooGxfNm0gMcwPAiYyKkLT0/4eDpw0rS/9yrhp93mbVqbMYpQSaYBMo6RDM1Q+bSKHdTQwyac/M96NhmmwC75VSggkfvqJK4o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746776006; c=relaxed/simple; bh=EZlt0cvhp3NrCL+YaqANcp2crpQa/wInckL0SK34i5E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Z2ik/p+FzZXCjjmh166hbvMGQ4WEHKLMhd8vlTcE8g+9vaQKmopZ2Vd9qT+Nl9IAuhSZapCELshLhnpNHvaq6kXvYbKSaCOewT6tLozs/IHBT9F1rCFVvc4+/i6WQ0GPZUuxlaQAr8I1WdnGei1axpG6pMQMtJw+MyZONnln0hI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Zv11n0v0hz4f3k6W for ; Fri, 9 May 2025 15:33:01 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.252]) by mail.maildlp.com (Postfix) with ESMTP id 734CB1A1A03 for ; Fri, 9 May 2025 15:33:20 +0800 (CST) Received: from hulk-vt.huawei.com (unknown [10.67.174.121]) by APP3 (Coremail) with SMTP id _Ch0CgCHJsG1rx1oiZnNLg--.58746S3; Fri, 09 May 2025 15:33:20 +0800 (CST) From: Chen Ridong To: akpm@linux-foundation.org, paulmck@kernel.org, bigeasy@linutronix.de, legion@kernel.org, roman.gushchin@linux.dev, brauner@kernel.org, tglx@linutronix.de, frederic@kernel.org, peterz@infradead.org, oleg@redhat.com, joel.granados@kernel.org, viro@zeniv.linux.org.uk, lorenzo.stoakes@oracle.com, avagin@google.com, mengensun@tencent.com, linux@weissschuh.net, jlayton@kernel.org, ruanjinjie@huawei.com, kees@kernel.org Cc: linux-kernel@vger.kernel.org, lujialin4@huawei.com, chenridong@huaweicloud.com Subject: [RFC next v2 1/5] user_namespace: add children list node Date: Fri, 9 May 2025 07:20:50 +0000 Message-Id: <20250509072054.148257-2-chenridong@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250509072054.148257-1-chenridong@huaweicloud.com> References: <20250509072054.148257-1-chenridong@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _Ch0CgCHJsG1rx1oiZnNLg--.58746S3 X-Coremail-Antispam: 1UD129KBjvJXoW7AF1Uur13ZFy8ZFWxtr1kXwb_yoW8uFy3pF ZIyr9xGws3Jr1qkryUWan5u34xWw48JF17Ca4v934rtryagFy0kr4UC3Wj9r15Xr48GrWY qFWjgrs0y3yUW37anT9S1TB71UUUUUJqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUQj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAa w2AFwI0_Jrv_JF1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrV C2j2WlYx0E2Ix0cI8IcVAFwI0_JF0_Jw1lYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE 7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxc IEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AFwI0_ZF0_GFyUMxAIw28IcxkI7VAKI48JMxC2 0s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI 0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE 14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20x vaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8 Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUUxhJUUUUU= X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ Content-Type: text/plain; charset="utf-8" From: Chen Ridong Add the 'children' and 'ns_node' fields to the user_namespace structure. This addition enables the user_namespace to locate all of its nested child namespaces efficiently. Signed-off-by: Chen Ridong --- include/linux/user_namespace.h | 2 ++ kernel/user.c | 2 ++ kernel/user_namespace.c | 4 ++++ 3 files changed, 8 insertions(+) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index a0bb6d012137..7b1e180227c8 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -78,6 +78,8 @@ struct user_namespace { struct uid_gid_map gid_map; struct uid_gid_map projid_map; struct user_namespace *parent; + struct list_head ns_node; + struct list_head children; int level; kuid_t owner; kgid_t group; diff --git a/kernel/user.c b/kernel/user.c index f46b1d41163b..3a712a6894fd 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -65,6 +65,8 @@ struct user_namespace init_user_ns =3D { .nr_extents =3D 1, }, }, + .ns_node =3D LIST_HEAD_INIT(init_user_ns.ns_node), + .children =3D LIST_HEAD_INIT(init_user_ns.children), .ns.count =3D REFCOUNT_INIT(3), .owner =3D GLOBAL_ROOT_UID, .group =3D GLOBAL_ROOT_GID, diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 682f40d5632d..b570536934cc 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -135,6 +135,9 @@ int create_user_ns(struct cred *new) ns->level =3D parent_ns->level + 1; ns->owner =3D owner; ns->group =3D group; + INIT_LIST_HEAD(&ns->children); + INIT_LIST_HEAD(&ns->ns_node); + list_add_tail_rcu(&ns->ns_node, &parent_ns->children); INIT_WORK(&ns->work, free_user_ns); for (i =3D 0; i < UCOUNT_COUNTS; i++) { ns->ucount_max[i] =3D INT_MAX; @@ -217,6 +220,7 @@ static void free_user_ns(struct work_struct *work) kfree(ns->binfmt_misc); #endif retire_userns_sysctls(ns); + list_del_rcu(&ns->ns_node); key_free_user_ns(ns); ns_free_inum(&ns->ns); kmem_cache_free(user_ns_cachep, ns); --=20 2.34.1