1 files changed, 35 insertions, 39 deletions

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 661a99a7dfbe..532bd7c46baf 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -403,7 +403,7 @@ static struct dentry *debugfs_start_creating(const char *name,
 	return dentry;
 }
 
-static struct dentry *failed_creating(struct dentry *dentry)
+static struct dentry *debugfs_failed_creating(struct dentry *dentry)
 {
 	inode_unlock(d_inode(dentry->d_parent));
 	dput(dentry);
@@ -411,7 +411,7 @@ static struct dentry *failed_creating(struct dentry *dentry)
 	return ERR_PTR(-ENOMEM);
 }
 
-static struct dentry *end_creating(struct dentry *dentry)
+static struct dentry *debugfs_end_creating(struct dentry *dentry)
 {
 	inode_unlock(d_inode(dentry->d_parent));
 	return dentry;
@@ -435,7 +435,7 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
 		return dentry;
 
 	if (!(debugfs_allow & DEBUGFS_ALLOW_API)) {
-		failed_creating(dentry);
+		debugfs_failed_creating(dentry);
 		return ERR_PTR(-EPERM);
 	}
 
@@ -443,7 +443,7 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
 	if (unlikely(!inode)) {
 		pr_err("out of free dentries, can not create file '%s'\n",
 		       name);
-		return failed_creating(dentry);
+		return debugfs_failed_creating(dentry);
 	}
 
 	inode->i_mode = mode;
@@ -458,7 +458,7 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
 
 	d_instantiate(dentry, inode);
 	fsnotify_create(d_inode(dentry->d_parent), dentry);
-	return end_creating(dentry);
+	return debugfs_end_creating(dentry);
 }
 
 struct dentry *debugfs_create_file_full(const char *name, umode_t mode,
@@ -585,7 +585,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 		return dentry;
 
 	if (!(debugfs_allow & DEBUGFS_ALLOW_API)) {
-		failed_creating(dentry);
+		debugfs_failed_creating(dentry);
 		return ERR_PTR(-EPERM);
 	}
 
@@ -593,7 +593,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 	if (unlikely(!inode)) {
 		pr_err("out of free dentries, can not create directory '%s'\n",
 		       name);
-		return failed_creating(dentry);
+		return debugfs_failed_creating(dentry);
 	}
 
 	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
@@ -605,7 +605,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 	d_instantiate(dentry, inode);
 	inc_nlink(d_inode(dentry->d_parent));
 	fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
-	return end_creating(dentry);
+	return debugfs_end_creating(dentry);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_dir);
 
@@ -632,7 +632,7 @@ struct dentry *debugfs_create_automount(const char *name,
 		return dentry;
 
 	if (!(debugfs_allow & DEBUGFS_ALLOW_API)) {
-		failed_creating(dentry);
+		debugfs_failed_creating(dentry);
 		return ERR_PTR(-EPERM);
 	}
 
@@ -640,7 +640,7 @@ struct dentry *debugfs_create_automount(const char *name,
 	if (unlikely(!inode)) {
 		pr_err("out of free dentries, can not create automount '%s'\n",
 		       name);
-		return failed_creating(dentry);
+		return debugfs_failed_creating(dentry);
 	}
 
 	make_empty_dir_inode(inode);
@@ -652,7 +652,7 @@ struct dentry *debugfs_create_automount(const char *name,
 	d_instantiate(dentry, inode);
 	inc_nlink(d_inode(dentry->d_parent));
 	fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
-	return end_creating(dentry);
+	return debugfs_end_creating(dentry);
 }
 EXPORT_SYMBOL(debugfs_create_automount);
 
@@ -699,13 +699,13 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
 		pr_err("out of free dentries, can not create symlink '%s'\n",
 		       name);
 		kfree(link);
-		return failed_creating(dentry);
+		return debugfs_failed_creating(dentry);
 	}
 	inode->i_mode = S_IFLNK | S_IRWXUGO;
 	inode->i_op = &debugfs_symlink_inode_operations;
 	inode->i_link = link;
 	d_instantiate(dentry, inode);
-	return end_creating(dentry);
+	return debugfs_end_creating(dentry);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_symlink);
 
@@ -842,7 +842,8 @@ int __printf(2, 3) debugfs_change_name(struct dentry *dentry, const char *fmt, .
 	int error = 0;
 	const char *new_name;
 	struct name_snapshot old_name;
-	struct dentry *parent, *target;
+	struct dentry *target;
+	struct renamedata rd = {};
 	struct inode *dir;
 	va_list ap;
 
@@ -855,36 +856,31 @@ int __printf(2, 3) debugfs_change_name(struct dentry *dentry, const char *fmt, .
 	if (!new_name)
 		return -ENOMEM;
 
-	parent = dget_parent(dentry);
-	dir = d_inode(parent);
-	inode_lock(dir);
+	rd.old_parent = dget_parent(dentry);
+	rd.new_parent = rd.old_parent;
+	rd.flags = RENAME_NOREPLACE;
+	target = lookup_noperm_unlocked(&QSTR(new_name), rd.new_parent);
+	if (IS_ERR(target))
+		return PTR_ERR(target);
 
-	take_dentry_name_snapshot(&old_name, dentry);
-
-	if (WARN_ON_ONCE(dentry->d_parent != parent)) {
-		error = -EINVAL;
-		goto out;
-	}
-	if (strcmp(old_name.name.name, new_name) == 0)
-		goto out;
-	target = lookup_noperm(&QSTR(new_name), parent);
-	if (IS_ERR(target)) {
-		error = PTR_ERR(target);
-		goto out;
-	}
-	if (d_really_is_positive(target)) {
-		dput(target);
-		error = -EINVAL;
+	error = start_renaming_two_dentries(&rd, dentry, target);
+	if (error) {
+		if (error == -EEXIST && target == dentry)
+			/* it isn't an error to rename a thing to itself */
+			error = 0;
 		goto out;
 	}
-	simple_rename_timestamp(dir, dentry, dir, target);
-	d_move(dentry, target);
-	dput(target);
+
+	dir = d_inode(rd.old_parent);
+	take_dentry_name_snapshot(&old_name, dentry);
+	simple_rename_timestamp(dir, dentry, dir, rd.new_dentry);
+	d_move(dentry, rd.new_dentry);
 	fsnotify_move(dir, dir, &old_name.name, d_is_dir(dentry), NULL, dentry);
-out:
 	release_dentry_name_snapshot(&old_name);
-	inode_unlock(dir);
-	dput(parent);
+	end_renaming(&rd);
+out:
+	dput(rd.old_parent);
+	dput(target);
 	kfree_const(new_name);
 	return error;
 }