Merge tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of changes for the driver core for 5.17-rc1.

  Lots of little things here, including:

   - kobj_type cleanups

   - auxiliary_bus documentation updates

   - auxiliary_device conversions for some drivers (relevant subsystems
     all have provided acks for these)

   - kernfs lock contention reduction for some workloads

   - other tiny cleanups and changes.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits)
  kobject documentation: remove default_attrs information
  drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb
  debugfs: lockdown: Allow reading debugfs files that are not world readable
  driver core: Make bus notifiers in right order in really_probe()
  driver core: Move driver_sysfs_remove() after driver_sysfs_add()
  firmware: edd: remove empty default_attrs array
  firmware: dmi-sysfs: use default_groups in kobj_type
  qemu_fw_cfg: use default_groups in kobj_type
  firmware: memmap: use default_groups in kobj_type
  sh: sq: use default_groups in kobj_type
  headers/uninline: Uninline single-use function: kobject_has_children()
  devtmpfs: mount with noexec and nosuid
  driver core: Simplify async probe test code by using ktime_ms_delta()
  nilfs2: use default_groups in kobj_type
  kobject: remove kset from struct kset_uevent_ops callbacks
  driver core: make kobj_type constant.
  driver core: platform: document registration-failure requirement
  vdpa/mlx5: Use auxiliary_device driver data helpers
  net/mlx5e: Use auxiliary_device driver data helpers
  soundwire: intel: Use auxiliary_device driver data helpers
  ...

9 files changed, 115 insertions, 72 deletions

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 7d162b0efbf0..950c63fa4d0b 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -147,7 +147,7 @@ static int debugfs_locked_down(struct inode *inode,
 			       struct file *filp,
 			       const struct file_operations *real_fops)
 {
-	if ((inode->i_mode & 07777) == 0444 &&
+	if ((inode->i_mode & 07777 & ~0444) == 0 &&
 	    !(filp->f_mode & FMODE_WRITE) &&
 	    !real_fops->unlocked_ioctl &&
 	    !real_fops->compat_ioctl &&
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 31384e7d6f90..0d3833a124a3 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -216,8 +216,7 @@ static int do_uevent(struct dlm_ls *ls, int in)
 	return ls->ls_uevent_result;
 }
 
-static int dlm_uevent(struct kset *kset, struct kobject *kobj,
-		      struct kobj_uevent_env *env)
+static int dlm_uevent(struct kobject *kobj, struct kobj_uevent_env *env)
 {
 	struct dlm_ls *ls = container_of(kobj, struct dlm_ls, ls_kobj);
 
diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index c0a34d9ddee4..a6002b2d146d 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -767,8 +767,7 @@ void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
 	wait_for_completion(&sdp->sd_kobj_unregister);
 }
 
-static int gfs2_uevent(struct kset *kset, struct kobject *kobj,
-		       struct kobj_uevent_env *env)
+static int gfs2_uevent(struct kobject *kobj, struct kobj_uevent_env *env)
 {
 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
 	struct super_block *s = sdp->sd_vfs;
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 8e0a1378a4b1..e6d9772ddb4c 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -17,7 +17,6 @@
 
 #include "kernfs-internal.h"
 
-DECLARE_RWSEM(kernfs_rwsem);
 static DEFINE_SPINLOCK(kernfs_rename_lock);	/* kn->parent and ->name */
 static char kernfs_pr_cont_buf[PATH_MAX];	/* protected by rename_lock */
 static DEFINE_SPINLOCK(kernfs_idr_lock);	/* root->ino_idr */
@@ -26,7 +25,7 @@ static DEFINE_SPINLOCK(kernfs_idr_lock);	/* root->ino_idr */
 
 static bool kernfs_active(struct kernfs_node *kn)
 {
-	lockdep_assert_held(&kernfs_rwsem);
+	lockdep_assert_held(&kernfs_root(kn)->kernfs_rwsem);
 	return atomic_read(&kn->active) >= 0;
 }
 
@@ -457,14 +456,15 @@ void kernfs_put_active(struct kernfs_node *kn)
  * return after draining is complete.
  */
 static void kernfs_drain(struct kernfs_node *kn)
-	__releases(&kernfs_rwsem) __acquires(&kernfs_rwsem)
+	__releases(&kernfs_root(kn)->kernfs_rwsem)
+	__acquires(&kernfs_root(kn)->kernfs_rwsem)
 {
 	struct kernfs_root *root = kernfs_root(kn);
 
-	lockdep_assert_held_write(&kernfs_rwsem);
+	lockdep_assert_held_write(&root->kernfs_rwsem);
 	WARN_ON_ONCE(kernfs_active(kn));
 
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 
 	if (kernfs_lockdep(kn)) {
 		rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
@@ -483,7 +483,7 @@ static void kernfs_drain(struct kernfs_node *kn)
 
 	kernfs_drain_open_files(kn);
 
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 }
 
 /**
@@ -718,11 +718,12 @@ err_unlock:
 int kernfs_add_one(struct kernfs_node *kn)
 {
 	struct kernfs_node *parent = kn->parent;
+	struct kernfs_root *root = kernfs_root(parent);
 	struct kernfs_iattrs *ps_iattr;
 	bool has_ns;
 	int ret;
 
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 
 	ret = -EINVAL;
 	has_ns = kernfs_ns_enabled(parent);
@@ -753,7 +754,7 @@ int kernfs_add_one(struct kernfs_node *kn)
 		ps_iattr->ia_mtime = ps_iattr->ia_ctime;
 	}
 
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 
 	/*
 	 * Activate the new node unless CREATE_DEACTIVATED is requested.
@@ -767,7 +768,7 @@ int kernfs_add_one(struct kernfs_node *kn)
 	return 0;
 
 out_unlock:
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 	return ret;
 }
 
@@ -788,7 +789,7 @@ static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent,
 	bool has_ns = kernfs_ns_enabled(parent);
 	unsigned int hash;
 
-	lockdep_assert_held(&kernfs_rwsem);
+	lockdep_assert_held(&kernfs_root(parent)->kernfs_rwsem);
 
 	if (has_ns != (bool)ns) {
 		WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",
@@ -820,7 +821,7 @@ static struct kernfs_node *kernfs_walk_ns(struct kernfs_node *parent,
 	size_t len;
 	char *p, *name;
 
-	lockdep_assert_held_read(&kernfs_rwsem);
+	lockdep_assert_held_read(&kernfs_root(parent)->kernfs_rwsem);
 
 	/* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */
 	spin_lock_irq(&kernfs_rename_lock);
@@ -859,11 +860,12 @@ struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
 					   const char *name, const void *ns)
 {
 	struct kernfs_node *kn;
+	struct kernfs_root *root = kernfs_root(parent);
 
-	down_read(&kernfs_rwsem);
+	down_read(&root->kernfs_rwsem);
 	kn = kernfs_find_ns(parent, name, ns);
 	kernfs_get(kn);
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 
 	return kn;
 }
@@ -883,11 +885,12 @@ struct kernfs_node *kernfs_walk_and_get_ns(struct kernfs_node *parent,
 					   const char *path, const void *ns)
 {
 	struct kernfs_node *kn;
+	struct kernfs_root *root = kernfs_root(parent);
 
-	down_read(&kernfs_rwsem);
+	down_read(&root->kernfs_rwsem);
 	kn = kernfs_walk_ns(parent, path, ns);
 	kernfs_get(kn);
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 
 	return kn;
 }
@@ -912,6 +915,7 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
 		return ERR_PTR(-ENOMEM);
 
 	idr_init(&root->ino_idr);
+	init_rwsem(&root->kernfs_rwsem);
 	INIT_LIST_HEAD(&root->supers);
 
 	/*
@@ -957,7 +961,13 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
  */
 void kernfs_destroy_root(struct kernfs_root *root)
 {
-	kernfs_remove(root->kn);	/* will also free @root */
+	/*
+	 *  kernfs_remove holds kernfs_rwsem from the root so the root
+	 *  shouldn't be freed during the operation.
+	 */
+	kernfs_get(root->kn);
+	kernfs_remove(root->kn);
+	kernfs_put(root->kn); /* will also free @root */
 }
 
 /**
@@ -1035,6 +1045,7 @@ struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent,
 static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
 {
 	struct kernfs_node *kn;
+	struct kernfs_root *root;
 
 	if (flags & LOOKUP_RCU)
 		return -ECHILD;
@@ -1046,18 +1057,19 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
 		/* If the kernfs parent node has changed discard and
 		 * proceed to ->lookup.
 		 */
-		down_read(&kernfs_rwsem);
 		spin_lock(&dentry->d_lock);
 		parent = kernfs_dentry_node(dentry->d_parent);
 		if (parent) {
+			spin_unlock(&dentry->d_lock);
+			root = kernfs_root(parent);
+			down_read(&root->kernfs_rwsem);
 			if (kernfs_dir_changed(parent, dentry)) {
-				spin_unlock(&dentry->d_lock);
-				up_read(&kernfs_rwsem);
+				up_read(&root->kernfs_rwsem);
 				return 0;
 			}
-		}
-		spin_unlock(&dentry->d_lock);
-		up_read(&kernfs_rwsem);
+			up_read(&root->kernfs_rwsem);
+		} else
+			spin_unlock(&dentry->d_lock);
 
 		/* The kernfs parent node hasn't changed, leave the
 		 * dentry negative and return success.
@@ -1066,7 +1078,8 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
 	}
 
 	kn = kernfs_dentry_node(dentry);
-	down_read(&kernfs_rwsem);
+	root = kernfs_root(kn);
+	down_read(&root->kernfs_rwsem);
 
 	/* The kernfs node has been deactivated */
 	if (!kernfs_active(kn))
@@ -1085,10 +1098,10 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
 	    kernfs_info(dentry->d_sb)->ns != kn->ns)
 		goto out_bad;
 
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 	return 1;
 out_bad:
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 	return 0;
 }
 
@@ -1102,10 +1115,12 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
 {
 	struct kernfs_node *parent = dir->i_private;
 	struct kernfs_node *kn;
+	struct kernfs_root *root;
 	struct inode *inode = NULL;
 	const void *ns = NULL;
 
-	down_read(&kernfs_rwsem);
+	root = kernfs_root(parent);
+	down_read(&root->kernfs_rwsem);
 	if (kernfs_ns_enabled(parent))
 		ns = kernfs_info(dir->i_sb)->ns;
 
@@ -1116,7 +1131,7 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
 		 * create a negative.
 		 */
 		if (!kernfs_active(kn)) {
-			up_read(&kernfs_rwsem);
+			up_read(&root->kernfs_rwsem);
 			return NULL;
 		}
 		inode = kernfs_get_inode(dir->i_sb, kn);
@@ -1131,7 +1146,7 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
 	 */
 	if (!IS_ERR(inode))
 		kernfs_set_rev(parent, dentry);
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 
 	/* instantiate and hash (possibly negative) dentry */
 	return d_splice_alias(inode, dentry);
@@ -1254,7 +1269,7 @@ static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos,
 {
 	struct rb_node *rbn;
 
-	lockdep_assert_held_write(&kernfs_rwsem);
+	lockdep_assert_held_write(&kernfs_root(root)->kernfs_rwsem);
 
 	/* if first iteration, visit leftmost descendant which may be root */
 	if (!pos)
@@ -1289,8 +1304,9 @@ static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos,
 void kernfs_activate(struct kernfs_node *kn)
 {
 	struct kernfs_node *pos;
+	struct kernfs_root *root = kernfs_root(kn);
 
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 
 	pos = NULL;
 	while ((pos = kernfs_next_descendant_post(pos, kn))) {
@@ -1304,14 +1320,14 @@ void kernfs_activate(struct kernfs_node *kn)
 		pos->flags |= KERNFS_ACTIVATED;
 	}
 
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 }
 
 static void __kernfs_remove(struct kernfs_node *kn)
 {
 	struct kernfs_node *pos;
 
-	lockdep_assert_held_write(&kernfs_rwsem);
+	lockdep_assert_held_write(&kernfs_root(kn)->kernfs_rwsem);
 
 	/*
 	 * Short-circuit if non-root @kn has already finished removal.
@@ -1381,9 +1397,11 @@ static void __kernfs_remove(struct kernfs_node *kn)
  */
 void kernfs_remove(struct kernfs_node *kn)
 {
-	down_write(&kernfs_rwsem);
+	struct kernfs_root *root = kernfs_root(kn);
+
+	down_write(&root->kernfs_rwsem);
 	__kernfs_remove(kn);
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 }
 
 /**
@@ -1469,8 +1487,9 @@ void kernfs_unbreak_active_protection(struct kernfs_node *kn)
 bool kernfs_remove_self(struct kernfs_node *kn)
 {
 	bool ret;
+	struct kernfs_root *root = kernfs_root(kn);
 
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 	kernfs_break_active_protection(kn);
 
 	/*
@@ -1498,9 +1517,9 @@ bool kernfs_remove_self(struct kernfs_node *kn)
 			    atomic_read(&kn->active) == KN_DEACTIVATED_BIAS)
 				break;
 
-			up_write(&kernfs_rwsem);
+			up_write(&root->kernfs_rwsem);
 			schedule();
-			down_write(&kernfs_rwsem);
+			down_write(&root->kernfs_rwsem);
 		}
 		finish_wait(waitq, &wait);
 		WARN_ON_ONCE(!RB_EMPTY_NODE(&kn->rb));
@@ -1513,7 +1532,7 @@ bool kernfs_remove_self(struct kernfs_node *kn)
 	 */
 	kernfs_unbreak_active_protection(kn);
 
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 	return ret;
 }
 
@@ -1530,6 +1549,7 @@ int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
 			     const void *ns)
 {
 	struct kernfs_node *kn;
+	struct kernfs_root *root;
 
 	if (!parent) {
 		WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n",
@@ -1537,13 +1557,14 @@ int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
 		return -ENOENT;
 	}
 
-	down_write(&kernfs_rwsem);
+	root = kernfs_root(parent);
+	down_write(&root->kernfs_rwsem);
 
 	kn = kernfs_find_ns(parent, name, ns);
 	if (kn)
 		__kernfs_remove(kn);
 
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 
 	if (kn)
 		return 0;
@@ -1562,6 +1583,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
 		     const char *new_name, const void *new_ns)
 {
 	struct kernfs_node *old_parent;
+	struct kernfs_root *root;
 	const char *old_name = NULL;
 	int error;
 
@@ -1569,7 +1591,8 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
 	if (!kn->parent)
 		return -EINVAL;
 
-	down_write(&kernfs_rwsem);
+	root = kernfs_root(kn);
+	down_write(&root->kernfs_rwsem);
 
 	error = -ENOENT;
 	if (!kernfs_active(kn) || !kernfs_active(new_parent) ||
@@ -1623,7 +1646,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
 
 	error = 0;
  out:
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 	return error;
 }
 
@@ -1694,11 +1717,14 @@ static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx)
 	struct dentry *dentry = file->f_path.dentry;
 	struct kernfs_node *parent = kernfs_dentry_node(dentry);
 	struct kernfs_node *pos = file->private_data;
+	struct kernfs_root *root;
 	const void *ns = NULL;
 
 	if (!dir_emit_dots(file, ctx))
 		return 0;
-	down_read(&kernfs_rwsem);
+
+	root = kernfs_root(parent);
+	down_read(&root->kernfs_rwsem);
 
 	if (kernfs_ns_enabled(parent))
 		ns = kernfs_info(dentry->d_sb)->ns;
@@ -1715,12 +1741,12 @@ static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx)
 		file->private_data = pos;
 		kernfs_get(pos);
 
-		up_read(&kernfs_rwsem);
+		up_read(&root->kernfs_rwsem);
 		if (!dir_emit(ctx, name, len, ino, type))
 			return 0;
-		down_read(&kernfs_rwsem);
+		down_read(&root->kernfs_rwsem);
 	}
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 	file->private_data = NULL;
 	ctx->pos = INT_MAX;
 	return 0;
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 60e2a86c535e..9414a7a60a9f 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -847,6 +847,7 @@ static void kernfs_notify_workfn(struct work_struct *work)
 {
 	struct kernfs_node *kn;
 	struct kernfs_super_info *info;
+	struct kernfs_root *root;
 repeat:
 	/* pop one off the notify_list */
 	spin_lock_irq(&kernfs_notify_lock);
@@ -859,8 +860,9 @@ repeat:
 	kn->attr.notify_next = NULL;
 	spin_unlock_irq(&kernfs_notify_lock);
 
+	root = kernfs_root(kn);
 	/* kick fsnotify */
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 
 	list_for_each_entry(info, &kernfs_root(kn)->supers, node) {
 		struct kernfs_node *parent;
@@ -898,7 +900,7 @@ repeat:
 		iput(inode);
 	}
 
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 	kernfs_put(kn);
 	goto repeat;
 }
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index c0eae1725435..3d783d80f5da 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -99,10 +99,11 @@ int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
 int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
 {
 	int ret;
+	struct kernfs_root *root = kernfs_root(kn);
 
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 	ret = __kernfs_setattr(kn, iattr);
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 	return ret;
 }
 
@@ -111,12 +112,14 @@ int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 {
 	struct inode *inode = d_inode(dentry);
 	struct kernfs_node *kn = inode->i_private;
+	struct kernfs_root *root;
 	int error;
 
 	if (!kn)
 		return -EINVAL;
 
-	down_write(&kernfs_rwsem);
+	root = kernfs_root(kn);
+	down_write(&root->kernfs_rwsem);
 	error = setattr_prepare(&init_user_ns, dentry, iattr);
 	if (error)
 		goto out;
@@ -129,7 +132,7 @@ int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	setattr_copy(&init_user_ns, inode, iattr);
 
 out:
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 	return error;
 }
 
@@ -184,13 +187,14 @@ int kernfs_iop_getattr(struct user_namespace *mnt_userns,
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct kernfs_node *kn = inode->i_private;
+	struct kernfs_root *root = kernfs_root(kn);
 
-	down_read(&kernfs_rwsem);
+	down_read(&root->kernfs_rwsem);
 	spin_lock(&inode->i_lock);
 	kernfs_refresh_inode(kn, inode);
 	generic_fillattr(&init_user_ns, inode, stat);
 	spin_unlock(&inode->i_lock);
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 
 	return 0;
 }
@@ -274,19 +278,21 @@ int kernfs_iop_permission(struct user_namespace *mnt_userns,
 			  struct inode *inode, int mask)
 {
 	struct kernfs_node *kn;
+	struct kernfs_root *root;
 	int ret;
 
 	if (mask & MAY_NOT_BLOCK)
 		return -ECHILD;
 
 	kn = inode->i_private;
+	root = kernfs_root(kn);
 
-	down_read(&kernfs_rwsem);
+	down_read(&root->kernfs_rwsem);
 	spin_lock(&inode->i_lock);
 	kernfs_refresh_inode(kn, inode);
 	ret = generic_permission(&init_user_ns, inode, mask);
 	spin_unlock(&inode->i_lock);
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 
 	return ret;
 }
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f2f909d09f52..cfa79715fc1a 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -236,6 +236,7 @@ struct dentry *kernfs_node_dentry(struct kernfs_node *kn,
 static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *kfc)
 {
 	struct kernfs_super_info *info = kernfs_info(sb);
+	struct kernfs_root *kf_root = kfc->root;
 	struct inode *inode;
 	struct dentry *root;
 
@@ -255,9 +256,9 @@ static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *k
 	sb->s_shrink.seeks = 0;
 
 	/* get root inode, initialize and unlock it */
-	down_read(&kernfs_rwsem);
+	down_read(&kf_root->kernfs_rwsem);
 	inode = kernfs_get_inode(sb, info->root->kn);
-	up_read(&kernfs_rwsem);
+	up_read(&kf_root->kernfs_rwsem);
 	if (!inode) {
 		pr_debug("kernfs: could not get root inode\n");
 		return -ENOMEM;
@@ -334,6 +335,7 @@ int kernfs_get_tree(struct fs_context *fc)
 
 	if (!sb->s_root) {
 		struct kernfs_super_info *info = kernfs_info(sb);
+		struct kernfs_root *root = kfc->root;
 
 		kfc->new_sb_created = true;
 
@@ -344,9 +346,9 @@ int kernfs_get_tree(struct fs_context *fc)
 		}
 		sb->s_flags |= SB_ACTIVE;
 
-		down_write(&kernfs_rwsem);
+		down_write(&root->kernfs_rwsem);
 		list_add(&info->node, &info->root->supers);
-		up_write(&kernfs_rwsem);
+		up_write(&root->kernfs_rwsem);
 	}
 
 	fc->root = dget(sb->s_root);
@@ -371,10 +373,11 @@ void kernfs_free_fs_context(struct fs_context *fc)
 void kernfs_kill_sb(struct super_block *sb)
 {
 	struct kernfs_super_info *info = kernfs_info(sb);
+	struct kernfs_root *root = info->root;
 
-	down_write(&kernfs_rwsem);
+	down_write(&root->kernfs_rwsem);
 	list_del(&info->node);
-	up_write(&kernfs_rwsem);
+	up_write(&root->kernfs_rwsem);
 
 	/*
 	 * Remove the superblock from fs_supers/s_instances
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 19a6c71c6ff5..0ab13824822f 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -113,11 +113,12 @@ static int kernfs_getlink(struct inode *inode, char *path)
 	struct kernfs_node *kn = inode->i_private;
 	struct kernfs_node *parent = kn->parent;
 	struct kernfs_node *target = kn->symlink.target_kn;
+	struct kernfs_root *root = kernfs_root(parent);
 	int error;
 
-	down_read(&kernfs_rwsem);
+	down_read(&root->kernfs_rwsem);
 	error = kernfs_get_target_path(parent, target, path);
-	up_read(&kernfs_rwsem);
+	up_read(&root->kernfs_rwsem);
 
 	return error;
 }
diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 81f35c5b5a40..379d22e28ed6 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -57,7 +57,7 @@ static void nilfs_##name##_attr_release(struct kobject *kobj) \
 	complete(&subgroups->sg_##name##_kobj_unregister); \
 } \
 static struct kobj_type nilfs_##name##_ktype = { \
-	.default_attrs	= nilfs_##name##_attrs, \
+	.default_groups	= nilfs_##name##_groups, \
 	.sysfs_ops	= &nilfs_##name##_attr_ops, \
 	.release	= nilfs_##name##_attr_release, \
 }
@@ -129,6 +129,7 @@ static struct attribute *nilfs_snapshot_attrs[] = {
 	NILFS_SNAPSHOT_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_snapshot);
 
 static ssize_t nilfs_snapshot_attr_show(struct kobject *kobj,
 					struct attribute *attr, char *buf)
@@ -166,7 +167,7 @@ static const struct sysfs_ops nilfs_snapshot_attr_ops = {
 };
 
 static struct kobj_type nilfs_snapshot_ktype = {
-	.default_attrs	= nilfs_snapshot_attrs,
+	.default_groups	= nilfs_snapshot_groups,
 	.sysfs_ops	= &nilfs_snapshot_attr_ops,
 	.release	= nilfs_snapshot_attr_release,
 };
@@ -226,6 +227,7 @@ static struct attribute *nilfs_mounted_snapshots_attrs[] = {
 	NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_mounted_snapshots);
 
 NILFS_DEV_INT_GROUP_OPS(mounted_snapshots, dev);
 NILFS_DEV_INT_GROUP_TYPE(mounted_snapshots, dev);
@@ -339,6 +341,7 @@ static struct attribute *nilfs_checkpoints_attrs[] = {
 	NILFS_CHECKPOINTS_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_checkpoints);
 
 NILFS_DEV_INT_GROUP_OPS(checkpoints, dev);
 NILFS_DEV_INT_GROUP_TYPE(checkpoints, dev);
@@ -428,6 +431,7 @@ static struct attribute *nilfs_segments_attrs[] = {
 	NILFS_SEGMENTS_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_segments);
 
 NILFS_DEV_INT_GROUP_OPS(segments, dev);
 NILFS_DEV_INT_GROUP_TYPE(segments, dev);
@@ -689,6 +693,7 @@ static struct attribute *nilfs_segctor_attrs[] = {
 	NILFS_SEGCTOR_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_segctor);
 
 NILFS_DEV_INT_GROUP_OPS(segctor, dev);
 NILFS_DEV_INT_GROUP_TYPE(segctor, dev);
@@ -816,6 +821,7 @@ static struct attribute *nilfs_superblock_attrs[] = {
 	NILFS_SUPERBLOCK_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_superblock);
 
 NILFS_DEV_INT_GROUP_OPS(superblock, dev);
 NILFS_DEV_INT_GROUP_TYPE(superblock, dev);
@@ -924,6 +930,7 @@ static struct attribute *nilfs_dev_attrs[] = {
 	NILFS_DEV_ATTR_LIST(README),
 	NULL,
 };
+ATTRIBUTE_GROUPS(nilfs_dev);
 
 static ssize_t nilfs_dev_attr_show(struct kobject *kobj,
 				    struct attribute *attr, char *buf)
@@ -961,7 +968,7 @@ static const struct sysfs_ops nilfs_dev_attr_ops = {
 };
 
 static struct kobj_type nilfs_dev_ktype = {
-	.default_attrs	= nilfs_dev_attrs,
+	.default_groups	= nilfs_dev_groups,
 	.sysfs_ops	= &nilfs_dev_attr_ops,
 	.release	= nilfs_dev_attr_release,
 };