From nobody Fri Jun 26 15:46:30 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C56A9C433F5 for ; Tue, 22 Feb 2022 07:07:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230379AbiBVHHu (ORCPT ); Tue, 22 Feb 2022 02:07:50 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:54290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230316AbiBVHHs (ORCPT ); Tue, 22 Feb 2022 02:07:48 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBA88AB479 for ; Mon, 21 Feb 2022 23:07:22 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 67F12B81716 for ; Tue, 22 Feb 2022 07:07:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BF87C340E8; Tue, 22 Feb 2022 07:07:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645513640; bh=bjQux4KfMguEvbyYEyLigPrNa+Mj1tsqrfaVMXRsHu0=; h=From:To:Cc:Subject:Date:From; b=19ApQUIZl9ruzcQI9gOb3QumHiahYkOI5Gr19WJHpi7iK86XxJhS2TGs6odPIkNF7 iUwE9NToTLDkV0L+ARfz42y6xIiWPaAx9jlCfe6neR+BCWVuFbJCDv5YZzgJZ5udjK FPBGJovToFYRy7z37WvPn3TtBYo5DpVg9ooV3p88= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Tejun Heo , Imran Khan Subject: [PATCH] kernfs: move struct kernfs_root out of the public view. Date: Tue, 22 Feb 2022 08:07:13 +0100 Message-Id: <20220222070713.3517679-1-gregkh@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4823; h=from:subject; bh=bjQux4KfMguEvbyYEyLigPrNa+Mj1tsqrfaVMXRsHu0=; b=owGbwMvMwCRo6H6F97bub03G02pJDEki3fPL3v1Zdr/OqU515a6lbBv/N92KmyQTzTb5I/OEt61a /mqBHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCRxdMZ5op8fTV/mXLUwfakCqVrGV Vf+Rl2GDPMD5kzvW75K8EN8xNU3socPOx+4dYBFwA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" There is no need to have struct kernfs_root be part of kernfs.h for the whole kernel to see and poke around it. Move it internal to kernfs code and provide a helper function, kernfs_root_to_node(), to handle the one field that kernfs users were directly accessing from the structure. Cc: Tejun Heo Cc: Imran Khan Signed-off-by: Greg Kroah-Hartman Acked-by: Tejun Heo --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4 ++-- fs/kernfs/dir.c | 9 +++++++++ fs/kernfs/kernfs-internal.h | 18 ++++++++++++++++++ fs/sysfs/mount.c | 2 +- include/linux/kernfs.h | 4 ++++ kernel/cgroup/cgroup.c | 4 ++-- 6 files changed, 36 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index b57b3db9a6a7..83f901e2c2df 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -3221,13 +3221,13 @@ static int __init rdtgroup_setup_root(void) =20 list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); =20 - ret =3D rdtgroup_add_files(rdt_root->kn, RF_CTRL_BASE); + ret =3D rdtgroup_add_files(kernfs_root_to_node(rdt_root), RF_CTRL_BASE); if (ret) { kernfs_destroy_root(rdt_root); goto out; } =20 - rdtgroup_default.kn =3D rdt_root->kn; + rdtgroup_default.kn =3D kernfs_root_to_node(rdt_root); kernfs_activate(rdtgroup_default.kn); =20 out: diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index e6d9772ddb4c..61a8edc4ba8b 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -970,6 +970,15 @@ void kernfs_destroy_root(struct kernfs_root *root) kernfs_put(root->kn); /* will also free @root */ } =20 +/** + * kernfs_root_to_node - return the kernfs_node associated with a kernfs_r= oot + * @root: root to use to lookup + */ +struct kernfs_node *kernfs_root_to_node(struct kernfs_root *root) +{ + return root->kn; +} + /** * kernfs_create_dir_ns - create a directory * @parent: parent in which to create a new directory diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index f9cc912c31e1..123a7edd25f5 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -31,6 +31,24 @@ struct kernfs_iattrs { atomic_t user_xattr_size; }; =20 +struct kernfs_root { + /* published fields */ + struct kernfs_node *kn; + unsigned int flags; /* KERNFS_ROOT_* flags */ + + /* private fields, do not use outside kernfs proper */ + struct idr ino_idr; + u32 last_id_lowbits; + u32 id_highbits; + struct kernfs_syscall_ops *syscall_ops; + + /* list of kernfs_super_info of this root, protected by kernfs_rwsem */ + struct list_head supers; + + wait_queue_head_t deactivate_waitq; + struct rw_semaphore kernfs_rwsem; +}; + /* +1 to avoid triggering overflow warning when negating it */ #define KN_DEACTIVATED_BIAS (INT_MIN + 1) =20 diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index e747c135c1d1..98467bb76737 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -103,7 +103,7 @@ int __init sysfs_init(void) if (IS_ERR(sysfs_root)) return PTR_ERR(sysfs_root); =20 - sysfs_root_kn =3D sysfs_root->kn; + sysfs_root_kn =3D kernfs_root_to_node(sysfs_root); =20 err =3D register_filesystem(&sysfs_fs_type); if (err) { diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 861c4f0f8a29..62aff082dc3f 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -185,6 +185,7 @@ struct kernfs_syscall_ops { struct kernfs_root *root); }; =20 +#if 0 struct kernfs_root { /* published fields */ struct kernfs_node *kn; @@ -202,6 +203,9 @@ struct kernfs_root { wait_queue_head_t deactivate_waitq; struct rw_semaphore kernfs_rwsem; }; +#endif + +struct kernfs_node *kernfs_root_to_node(struct kernfs_root *root); =20 struct kernfs_open_file { /* published fields */ diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index b31e1465868a..a800c3b1b795 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1302,7 +1302,7 @@ static struct css_set *find_css_set(struct css_set *o= ld_cset, =20 struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root) { - struct cgroup *root_cgrp =3D kf_root->kn->priv; + struct cgroup *root_cgrp =3D kernfs_root_to_node(kf_root)->priv; =20 return root_cgrp->root; } @@ -2025,7 +2025,7 @@ int cgroup_setup_root(struct cgroup_root *root, u16 s= s_mask) ret =3D PTR_ERR(root->kf_root); goto exit_root_id; } - root_cgrp->kn =3D root->kf_root->kn; + root_cgrp->kn =3D kernfs_root_to_node(root->kf_root); WARN_ON_ONCE(cgroup_ino(root_cgrp) !=3D 1); root_cgrp->ancestor_ids[0] =3D cgroup_id(root_cgrp); =20 --=20 2.35.1