From f2eb478f2f322217aa642e11c1cc011f99c797e6 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 22 Feb 2022 08:07:13 +0100 Subject: [PATCH] kernfs: move struct kernfs_root out of the public view. 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: Imran Khan Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220222070713.3517679-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- 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/resctrl/rdtgroup.c index b57b3db..83f901e 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) list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); - ret = rdtgroup_add_files(rdt_root->kn, RF_CTRL_BASE); + ret = rdtgroup_add_files(kernfs_root_to_node(rdt_root), RF_CTRL_BASE); if (ret) { kernfs_destroy_root(rdt_root); goto out; } - rdtgroup_default.kn = rdt_root->kn; + rdtgroup_default.kn = kernfs_root_to_node(rdt_root); kernfs_activate(rdtgroup_default.kn); out: diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index e6d9772..61a8edc 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -971,6 +971,15 @@ void kernfs_destroy_root(struct kernfs_root *root) } /** + * kernfs_root_to_node - return the kernfs_node associated with a kernfs_root + * @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 * @name: name of the new directory diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index fc3b32f..eeaa779b 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; }; +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) diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index e747c135..98467bb 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); - sysfs_root_kn = sysfs_root->kn; + sysfs_root_kn = kernfs_root_to_node(sysfs_root); err = register_filesystem(&sysfs_fs_type); if (err) { diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 861c4f0..62aff08 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -185,6 +185,7 @@ struct kernfs_syscall_ops { struct kernfs_root *root); }; +#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); struct kernfs_open_file { /* published fields */ diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index b31e146..a800c3b 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 *old_cset, struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root) { - struct cgroup *root_cgrp = kf_root->kn->priv; + struct cgroup *root_cgrp = kernfs_root_to_node(kf_root)->priv; return root_cgrp->root; } @@ -2025,7 +2025,7 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) ret = PTR_ERR(root->kf_root); goto exit_root_id; } - root_cgrp->kn = root->kf_root->kn; + root_cgrp->kn = kernfs_root_to_node(root->kf_root); WARN_ON_ONCE(cgroup_ino(root_cgrp) != 1); root_cgrp->ancestor_ids[0] = cgroup_id(root_cgrp); -- 2.7.4