From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4073833DEFD; Wed, 29 Oct 2025 12:22:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761740533; cv=none; b=EoU1riA5M0miSiPAKQ85v7FEbPtsq/vhPQrq2VNDfNQ6DzWCR6hSTcQ88Vs/Gj3q8Kytyzj+4uzo3wRMfKJ5M+p+AaDCcqaSw0Z4vslfYrlYROH+OqYSzOjTuHMLpgqDANRejkQnWE3wtwOGz3C0H5QM3Q6LyYuLqyzgxF2DhNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761740533; c=relaxed/simple; bh=zBZ8k9vNKGmXFGtRmtowfVJFJn71uOWCNT+vTVEJ+6E=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=cfUtHSfArPNL1nV6crvMJFiGQLEUusGbNOTMKBJa5Q0a6Hqc9XwrN8V3hYP2/LZ5dsYHU87rlFxI/54ZWYJjFfx6/4ieFsDgohZ302K8R0RCEv/DBdDpZhJ0QPzGs422paTKgewx7RsY7B/xAwhcRtTuGPxOPqs4PNVdu6DL5Ro= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UW8SoFp5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UW8SoFp5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17928C116B1; Wed, 29 Oct 2025 12:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761740529; bh=zBZ8k9vNKGmXFGtRmtowfVJFJn71uOWCNT+vTVEJ+6E=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=UW8SoFp5uwVT3blwSS8V3GwymHuX9cctb5jeEDv+MYcbnLdjcGquBFCR2vSoMf2Oj Zqz65924uCquVOK2XjRqreA/kxiSb5exO2Dp/+oj6Dg62xohxk/7Ni25nVgpEkmd4o ndhpbWTkZ0f+dCK32Fsa72/1IRACpr7zoe8W7ER1mY7A0c29MrcFNVmXWV3Ubmmkfq KCz6Mq09peOXBWcKVC52DPu94aQP6Z5aEBQUVEj/CnZc8lk4hN0C3vjMcpRYSVF4kL Faj/poPBUYfWPkavsliD/tUmakIghotxGjUiV77Xr+eNqDGgOyP8bMIQcMmA9uXwIl E7W9qyjto1Rsw== From: Christian Brauner Date: Wed, 29 Oct 2025 13:20:31 +0100 Subject: [PATCH v4 18/72] nstree: add unified namespace list Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251029-work-namespace-nstree-listns-v4-18-2e6f823ebdc0@kernel.org> References: <20251029-work-namespace-nstree-listns-v4-0-2e6f823ebdc0@kernel.org> In-Reply-To: <20251029-work-namespace-nstree-listns-v4-0-2e6f823ebdc0@kernel.org> To: linux-fsdevel@vger.kernel.org, Josef Bacik , Jeff Layton Cc: Jann Horn , Mike Yuan , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , Lennart Poettering , Daan De Meyer , Aleksa Sarai , Amir Goldstein , Tejun Heo , Johannes Weiner , Thomas Gleixner , Alexander Viro , Jan Kara , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Eric Dumazet , Jakub Kicinski , netdev@vger.kernel.org, Arnd Bergmann , Christian Brauner X-Mailer: b4 0.15-dev-96507 X-Developer-Signature: v=1; a=openpgp-sha256; l=6556; i=brauner@kernel.org; h=from:subject:message-id; bh=zBZ8k9vNKGmXFGtRmtowfVJFJn71uOWCNT+vTVEJ+6E=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQysfVqWTwJOlr+6aKotNxVR8fnSy+Y3an+plnErp6l0 cD9ySyno5SFQYyLQVZMkcWh3SRcbjlPxWajTA2YOaxMIEMYuDgFYCJLGBn+179i+q7H3/GOx+jW We7DLIvWPJwbaeo4W7RT7hYP/8eNRYwMe6PTp61VlhGZuOfiD6nf5obvZhX3VKyum+1p9rTsX/M EPgA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Allow to walk the unified namespace list completely locklessly. Signed-off-by: Christian Brauner --- fs/namespace.c | 1 + init/version-timestamp.c | 1 + ipc/msgutil.c | 1 + kernel/cgroup/cgroup.c | 1 + kernel/nscommon.c | 1 + kernel/nstree.c | 13 ++++++++++++- kernel/pid.c | 1 + kernel/time/namespace.c | 1 + kernel/user.c | 1 + 9 files changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 3e0361c4c138..1cb4cc8f7f5f 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5995,6 +5995,7 @@ struct mnt_namespace init_mnt_ns = { .mounts = RB_ROOT, .poll = __WAIT_QUEUE_HEAD_INITIALIZER(init_mnt_ns.poll), .ns.ns_list_node = LIST_HEAD_INIT(init_mnt_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_mnt_ns.ns.ns_unified_list_node), .ns.ns_owner_entry = LIST_HEAD_INIT(init_mnt_ns.ns.ns_owner_entry), .ns.ns_owner = LIST_HEAD_INIT(init_mnt_ns.ns.ns_owner), }; diff --git a/init/version-timestamp.c b/init/version-timestamp.c index e5c278dabecf..cd6f435d5fde 100644 --- a/init/version-timestamp.c +++ b/init/version-timestamp.c @@ -22,6 +22,7 @@ struct uts_namespace init_uts_ns = { .user_ns = &init_user_ns, .ns.inum = ns_init_inum(&init_uts_ns), .ns.ns_list_node = LIST_HEAD_INIT(init_uts_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_uts_ns.ns.ns_unified_list_node), .ns.ns_owner_entry = LIST_HEAD_INIT(init_uts_ns.ns.ns_owner_entry), .ns.ns_owner = LIST_HEAD_INIT(init_uts_ns.ns.ns_owner), #ifdef CONFIG_UTS_NS diff --git a/ipc/msgutil.c b/ipc/msgutil.c index ce1de73725c0..3708f325228d 100644 --- a/ipc/msgutil.c +++ b/ipc/msgutil.c @@ -32,6 +32,7 @@ struct ipc_namespace init_ipc_ns = { .user_ns = &init_user_ns, .ns.inum = ns_init_inum(&init_ipc_ns), .ns.ns_list_node = LIST_HEAD_INIT(init_ipc_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_ipc_ns.ns.ns_unified_list_node), .ns.ns_owner_entry = LIST_HEAD_INIT(init_ipc_ns.ns.ns_owner_entry), .ns.ns_owner = LIST_HEAD_INIT(init_ipc_ns.ns.ns_owner), #ifdef CONFIG_IPC_NS diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 9fa082e2eb1a..a0eee0785080 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -258,6 +258,7 @@ struct cgroup_namespace init_cgroup_ns = { .root_cset = &init_css_set, .ns.ns_type = ns_common_type(&init_cgroup_ns), .ns.ns_list_node = LIST_HEAD_INIT(init_cgroup_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_cgroup_ns.ns.ns_unified_list_node), .ns.ns_owner_entry = LIST_HEAD_INIT(init_cgroup_ns.ns.ns_owner_entry), .ns.ns_owner = LIST_HEAD_INIT(init_cgroup_ns.ns.ns_owner), }; diff --git a/kernel/nscommon.c b/kernel/nscommon.c index bd4cf8bb8a77..affaf91c2074 100644 --- a/kernel/nscommon.c +++ b/kernel/nscommon.c @@ -64,6 +64,7 @@ int __ns_common_init(struct ns_common *ns, u32 ns_type, const struct proc_ns_ope RB_CLEAR_NODE(&ns->ns_unified_tree_node); RB_CLEAR_NODE(&ns->ns_owner_tree_node); INIT_LIST_HEAD(&ns->ns_list_node); + INIT_LIST_HEAD(&ns->ns_unified_list_node); ns->ns_owner_tree = RB_ROOT; INIT_LIST_HEAD(&ns->ns_owner); INIT_LIST_HEAD(&ns->ns_owner_entry); diff --git a/kernel/nstree.c b/kernel/nstree.c index 1779fa314a7d..100145e5edd1 100644 --- a/kernel/nstree.c +++ b/kernel/nstree.c @@ -8,6 +8,7 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(ns_tree_lock); static struct rb_root ns_unified_tree = RB_ROOT; /* protected by ns_tree_lock */ +static LIST_HEAD(ns_unified_list); /* protected by ns_tree_lock */ /** * struct ns_tree - Namespace tree @@ -154,7 +155,13 @@ void __ns_tree_add_raw(struct ns_common *ns, struct ns_tree *ns_tree) else list_add_rcu(&ns->ns_list_node, &node_to_ns(prev)->ns_list_node); + /* Add to unified tree and list */ rb_find_add_rcu(&ns->ns_unified_tree_node, &ns_unified_tree, ns_cmp_unified); + prev = rb_prev(&ns->ns_unified_tree_node); + if (!prev) + list_add_rcu(&ns->ns_unified_list_node, &ns_unified_list); + else + list_add_rcu(&ns->ns_unified_list_node, &node_to_ns_unified(prev)->ns_unified_list_node); if (ops) { struct user_namespace *user_ns; @@ -203,11 +210,15 @@ void __ns_tree_remove(struct ns_common *ns, struct ns_tree *ns_tree) write_seqlock(&ns_tree_lock); rb_erase(&ns->ns_tree_node, &ns_tree->ns_tree); - rb_erase(&ns->ns_unified_tree_node, &ns_unified_tree); RB_CLEAR_NODE(&ns->ns_tree_node); list_bidir_del_rcu(&ns->ns_list_node); + rb_erase(&ns->ns_unified_tree_node, &ns_unified_tree); + RB_CLEAR_NODE(&ns->ns_unified_tree_node); + + list_bidir_del_rcu(&ns->ns_unified_list_node); + /* Remove from owner's rbtree if this namespace has an owner */ if (ops) { user_ns = ops->owner(ns); diff --git a/kernel/pid.c b/kernel/pid.c index 8134c40b2584..22a0440a62fa 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -80,6 +80,7 @@ struct pid_namespace init_pid_ns = { .user_ns = &init_user_ns, .ns.inum = ns_init_inum(&init_pid_ns), .ns.ns_list_node = LIST_HEAD_INIT(init_pid_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_pid_ns.ns.ns_unified_list_node), .ns.ns_owner_entry = LIST_HEAD_INIT(init_pid_ns.ns.ns_owner_entry), .ns.ns_owner = LIST_HEAD_INIT(init_pid_ns.ns.ns_owner), #ifdef CONFIG_PID_NS diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index f543c4a83229..6a41269b1a5d 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -488,6 +488,7 @@ struct time_namespace init_time_ns = { .ns.ns_owner = LIST_HEAD_INIT(init_time_ns.ns.ns_owner), .frozen_offsets = true, .ns.ns_list_node = LIST_HEAD_INIT(init_time_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_time_ns.ns.ns_unified_list_node), }; void __init time_ns_init(void) diff --git a/kernel/user.c b/kernel/user.c index e392768ccd44..68fe16617d38 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -72,6 +72,7 @@ struct user_namespace init_user_ns = { .group = GLOBAL_ROOT_GID, .ns.inum = ns_init_inum(&init_user_ns), .ns.ns_list_node = LIST_HEAD_INIT(init_user_ns.ns.ns_list_node), + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_user_ns.ns.ns_unified_list_node), .ns.ns_owner_entry = LIST_HEAD_INIT(init_user_ns.ns.ns_owner_entry), .ns.ns_owner = LIST_HEAD_INIT(init_user_ns.ns.ns_owner), #ifdef CONFIG_USER_NS -- 2.47.3