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 E05DC30171A; Mon, 3 Nov 2025 11:22:06 +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=1762168927; cv=none; b=NaRA4DFgxX4g/lDOe6NV898xJ9TcSyyR34i1dR86Wj1QeTiSbodfOzcWMqpFPRGcmsv3v3lPPtVTT979h8nwe8YOJj2HwkVajlnER4icm4O1QNs3SJk5UavCNejEmXUuT4YiUgRlJVd++VMPhj7KHivLOI1/3o6wGWF+Dj5EjxA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762168927; c=relaxed/simple; bh=zZlF5mFS0f/Oq95hrQaLrWEgcxubppt7A+bJPXZk8eE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jmPsyzbDY/7IJXhm1k+75I7CwI6JRH52HF2v53ZVeCvMYMYDZxQKYR1AHZBVSWtVuN1PXU0VHAGOB4auMhDRbUmN3K7hczWVmKzvXNx6+oF7AvusCfmN34pydvsTJEtdvTm0wZzdumwR0SiK82G3jH6o+wUdXUT7H9US2HWNtls= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tKubhfGZ; 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="tKubhfGZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDD38C4CEE7; Mon, 3 Nov 2025 11:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762168926; bh=zZlF5mFS0f/Oq95hrQaLrWEgcxubppt7A+bJPXZk8eE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tKubhfGZ1E3MStl1BRbOzd2Q8vO1r0ckcnlGtZNrHz/RNHeEjLwXnDvVXIV0c6TYz KNKPv8aObnAuFGp3Z55H2JmW2+92bW4vRZjS6IyEegkcbwMNRWtRu2UToQNkZtro3m g5ozgD6/Jbdhk/RN4XxvUAr9UjaLb5OhQbBUBf8tfJcg4LetahlzKygwN78VAKG3bY uLgDEg203RIUt31Ie/o7VV8TTHy94ZLqBWKZZl73KTARp2BEgaa5nygNPr90jeKk+F KHH2mNubBAoPfyxFwy7RZ6a4g/BnE+ssGrAYUXuaYea164SPMWY5wjkLX/RGhBvut8 5GzQycJcNdYWg== Date: Mon, 3 Nov 2025 12:21:59 +0100 From: Christian Brauner To: Thomas Gleixner Cc: linux-fsdevel@vger.kernel.org, Josef Bacik , Jeff Layton , Jann Horn , Mike Yuan , Zbigniew =?utf-8?Q?J=C4=99drzejewski-Szmek?= , Lennart Poettering , Daan De Meyer , Aleksa Sarai , Amir Goldstein , Tejun Heo , Johannes Weiner , 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 Subject: Re: [PATCH v4 18/72] nstree: add unified namespace list Message-ID: <20251103-morsch-kunst-e8d040981325@brauner> References: <20251029-work-namespace-nstree-listns-v4-0-2e6f823ebdc0@kernel.org> <20251029-work-namespace-nstree-listns-v4-18-2e6f823ebdc0@kernel.org> <87ecqhy2y5.ffs@tglx> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87ecqhy2y5.ffs@tglx> On Sat, Nov 01, 2025 at 08:20:50PM +0100, Thomas Gleixner wrote: > Christian! > > On Wed, Oct 29 2025 at 13:20, Christian Brauner wrote: > > --- 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), > > Sorry that I did not catch that earlier, but > > 1) this screws up the proper tabular struct initializer > > 2) the churn of touching every compile time struct each time you add a > new field and add the same stupid initialization to each of them > can be avoided, when you do something like the uncompiled below. > You get the idea. > > Thanks, Nice! I'm stealing that and I'll slap a Suggested-by for you on it. Thanks! > > tglx > --- > fs/namespace.c | 9 +-------- > include/linux/ns_common.h | 12 ++++++++++++ > init/version-timestamp.c | 9 +-------- > ipc/msgutil.c | 9 +-------- > kernel/pid.c | 8 +------- > kernel/time/namespace.c | 9 +-------- > kernel/user.c | 9 +-------- > 7 files changed, 18 insertions(+), 47 deletions(-) > > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -5985,19 +5985,12 @@ SYSCALL_DEFINE4(listmount, const struct > } > > struct mnt_namespace init_mnt_ns = { > - .ns.inum = ns_init_inum(&init_mnt_ns), > + .ns = NS_COMMON_INIT(init_mnt_ns, 1, 1), > .ns.ops = &mntns_operations, > .user_ns = &init_user_ns, > - .ns.__ns_ref = REFCOUNT_INIT(1), > - .ns.__ns_ref_active = ATOMIC_INIT(1), > - .ns.ns_type = ns_common_type(&init_mnt_ns), > .passive = REFCOUNT_INIT(1), > .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), > }; > > static void __init init_mount_tree(void) > --- a/include/linux/ns_common.h > +++ b/include/linux/ns_common.h > @@ -129,6 +129,18 @@ struct ns_common { > }; > }; > > +#define NS_COMMON_INIT(nsname, refs, active) \ > +{ \ > + .ns_type = ns_common_type(&nsname), \ > + .inum = ns_init_inum(&nsname), \ > + .__ns_ref = REFCOUNT_INIT(refs), \ > + .__ns_ref_active = ATOMIC_INIT(active), \ > + .ns_list_node = LIST_HEAD_INIT(nsname.ns.ns_list_node), \ > + .ns_unified_list_node = LIST_HEAD_INIT(nsname.ns.ns_unified_list_node), \ > + .ns_owner_entry = LIST_HEAD_INIT(nsname.ns.ns_owner_entry), \ > + .ns_owner = LIST_HEAD_INIT(nsname.ns.ns_owner), \ > +} > + > int __ns_common_init(struct ns_common *ns, u32 ns_type, const struct proc_ns_operations *ops, int inum); > void __ns_common_free(struct ns_common *ns); > > --- a/init/version-timestamp.c > +++ b/init/version-timestamp.c > @@ -8,9 +8,7 @@ > #include > > struct uts_namespace init_uts_ns = { > - .ns.ns_type = ns_common_type(&init_uts_ns), > - .ns.__ns_ref = REFCOUNT_INIT(2), > - .ns.__ns_ref_active = ATOMIC_INIT(1), > + .ns = NS_COMMON_INIT(init_uts_ns, 2, 1), > .name = { > .sysname = UTS_SYSNAME, > .nodename = UTS_NODENAME, > @@ -20,11 +18,6 @@ struct uts_namespace init_uts_ns = { > .domainname = UTS_DOMAINNAME, > }, > .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 > .ns.ops = &utsns_operations, > #endif > --- a/ipc/msgutil.c > +++ b/ipc/msgutil.c > @@ -27,18 +27,11 @@ DEFINE_SPINLOCK(mq_lock); > * and not CONFIG_IPC_NS. > */ > struct ipc_namespace init_ipc_ns = { > - .ns.__ns_ref = REFCOUNT_INIT(1), > - .ns.__ns_ref_active = ATOMIC_INIT(1), > + .ns = NS_COMMON_INIT(init_ipc_ns, 1, 1), > .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 > .ns.ops = &ipcns_operations, > #endif > - .ns.ns_type = ns_common_type(&init_ipc_ns), > }; > > struct msg_msgseg { > --- a/kernel/pid.c > +++ b/kernel/pid.c > @@ -71,18 +71,12 @@ static int pid_max_max = PID_MAX_LIMIT; > * the scheme scales to up to 4 million PIDs, runtime. > */ > struct pid_namespace init_pid_ns = { > - .ns.__ns_ref = REFCOUNT_INIT(2), > - .ns.__ns_ref_active = ATOMIC_INIT(1), > + .ns = NS_COMMON_INIT(init_pid_ns, 2, 1), > .idr = IDR_INIT(init_pid_ns.idr), > .pid_allocated = PIDNS_ADDING, > .level = 0, > .child_reaper = &init_task, > .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 > .ns.ops = &pidns_operations, > #endif > --- a/kernel/time/namespace.c > +++ b/kernel/time/namespace.c > @@ -478,17 +478,10 @@ const struct proc_ns_operations timens_f > }; > > struct time_namespace init_time_ns = { > - .ns.ns_type = ns_common_type(&init_time_ns), > - .ns.__ns_ref = REFCOUNT_INIT(3), > - .ns.__ns_ref_active = ATOMIC_INIT(1), > + .ns = NS_COMMON_INIT(init_time_ns, 3, 1), > .user_ns = &init_user_ns, > - .ns.inum = ns_init_inum(&init_time_ns), > .ns.ops = &timens_operations, > - .ns.ns_owner_entry = LIST_HEAD_INIT(init_time_ns.ns.ns_owner_entry), > - .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) > --- a/kernel/user.c > +++ b/kernel/user.c > @@ -65,16 +65,9 @@ struct user_namespace init_user_ns = { > .nr_extents = 1, > }, > }, > - .ns.ns_type = ns_common_type(&init_user_ns), > - .ns.__ns_ref = REFCOUNT_INIT(3), > - .ns.__ns_ref_active = ATOMIC_INIT(1), > + .ns = NS_COMMON_INIT(init_user_ns, 3, 1), > .owner = GLOBAL_ROOT_UID, > .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 > .ns.ops = &userns_operations, > #endif