From nobody Tue Feb 10 01:15:43 2026 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 ADE0426FD90 for ; Fri, 9 May 2025 07:06:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746774419; cv=none; b=IBF4lsIn7NmqZEDI59PabPDEASIGgr5pCwAzVBNZvKJGofsJ7gE9n0foBvZLwCWiqgYL8aqv+eQ9uMtc+KMJh/ACS3TuwmZqS4CvBywHzY/peV4ATUSuAtSbF7FUvtA4vhqPpgAJoiZzzw8FguIqQKvL9AzgeM9VsdR64oYNII4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746774419; c=relaxed/simple; bh=EZlt0cvhp3NrCL+YaqANcp2crpQa/wInckL0SK34i5E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TzXV4pz/4QrOVue3PGOELfh2qsQPvIUoio/3JDsbV2fvQ/4Qp12Ff7vJNV49mcxTwMjlIa5ZgMaXVVxXTyDKEi+eHBVfaP4jlNCG/EhMbDiWGR7OwlgbGEYtZruxvqWhnMjRIS82aLh6htGTyIq2EYAj7vafJGsvwTEk5SX8HDk= 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=45.249.212.56 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 [172.19.93.142]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4Zv0R86YR7z4f3jXc for ; Fri, 9 May 2025 15:06:28 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.252]) by mail.maildlp.com (Postfix) with ESMTP id 7DCAE1A084B for ; Fri, 9 May 2025 15:06:53 +0800 (CST) Received: from hulk-vt.huawei.com (unknown [10.67.174.121]) by APP3 (Coremail) with SMTP id _Ch0CgAnesR4qR1ofcXLLg--.60961S3; Fri, 09 May 2025 15:06:53 +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 1/5] user_namespace: add children list node Date: Fri, 9 May 2025 06:54:07 +0000 Message-Id: <20250509065417.147515-2-chenridong@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250509065417.147515-1-chenridong@huaweicloud.com> References: <20250509065417.147515-1-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: _Ch0CgAnesR4qR1ofcXLLg--.60961S3 X-Coremail-Antispam: 1UD129KBjvJXoW7AF1Uur13ZFy8ZFWxtr1kXwb_yoW8uFy3pF ZIyr9xGws3Jr1qkryUWan5u34xWw48JF17Ca4v934rtryagFy0kr4UC3Wj9r15Xr48GrWY qFWjgrs0y3yUW37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUm014x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCY1x0262kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWU JVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67 kF1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY 6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0x vEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVj vjDU0xZFpf9x0pRlJPiUUUUU= 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