kernfs: add @mode to kernfs_create_dir[_ns]()

sysfs assumed 0755 for all newly created directories and kernfs
inherited it.  This assumption is unnecessarily restrictive and
inconsistent with kernfs_create_file[_ns]().  This patch adds @mode
parameter to kernfs_create_dir[_ns]() and update uses in sysfs
accordingly.  Among others, this will be useful for implementations of
the planned ->mkdir() method.

This patch doesn't introduce any behavior differences.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/kernfs/dir.c

@@ -639,22 +639,23 @@ void kernfs_destroy_root(struct kernfs_root *root)
  * kernfs_create_dir_ns - create a directory
  * @parent: parent in which to create a new directory
  * @name: name of the new directory
+ * @mode: mode of the new directory
  * @priv: opaque data associated with the new directory
  * @ns: optional namespace tag of the directory
  *
  * Returns the created node on success, ERR_PTR() value on failure.
  */
 struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
-					 const char *name, void *priv,
-					 const void *ns)
+					 const char *name, umode_t mode,
+					 void *priv, const void *ns)
 {
-	umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
 	struct kernfs_addrm_cxt acxt;
 	struct kernfs_node *kn;
 	int rc;
 
 	/* allocate */
-	kn = kernfs_new_node(kernfs_root(parent), name, mode, KERNFS_DIR);
+	kn = kernfs_new_node(kernfs_root(parent), name, mode | S_IFDIR,
+			     KERNFS_DIR);
 	if (!kn)
 		return ERR_PTR(-ENOMEM);
 

fs/sysfs/dir.c

@@ -73,7 +73,8 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 	if (!parent)
 		return -ENOENT;
 
-	kn = kernfs_create_dir_ns(parent, kobject_name(kobj), kobj, ns);
+	kn = kernfs_create_dir_ns(parent, kobject_name(kobj),
+				  S_IRWXU | S_IRUGO | S_IXUGO, kobj, ns);
 	if (IS_ERR(kn)) {
 		if (PTR_ERR(kn) == -EEXIST)
 			sysfs_warn_dup(parent, kobject_name(kobj));

fs/sysfs/group.c

@@ -100,7 +100,8 @@ static int internal_create_group(struct kobject *kobj, int update,
 		return -EINVAL;
 	}
 	if (grp->name) {
-		kn = kernfs_create_dir(kobj->sd, grp->name, kobj);
+		kn = kernfs_create_dir(kobj->sd, grp->name,
+				       S_IRWXU | S_IRUGO | S_IXUGO, kobj);
 		if (IS_ERR(kn)) {
 			if (PTR_ERR(kn) == -EEXIST)
 				sysfs_warn_dup(kobj->sd, grp->name);

include/linux/kernfs.h

@@ -210,8 +210,8 @@ struct kernfs_root *kernfs_create_root(void *priv);
 void kernfs_destroy_root(struct kernfs_root *root);
 
 struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
-					 const char *name, void *priv,
-					 const void *ns);
+					 const char *name, umode_t mode,
+					 void *priv, const void *ns);
 struct kernfs_node *kernfs_create_file_ns_key(struct kernfs_node *parent,
 					      const char *name,
 					      umode_t mode, loff_t size,
@@ -260,8 +260,8 @@ static inline struct kernfs_root *kernfs_create_root(void *priv)
 static inline void kernfs_destroy_root(struct kernfs_root *root) { }
 
 static inline struct kernfs_node *
-kernfs_create_dir_ns(struct kernfs_node *parent, const char *name, void *priv,
-		     const void *ns)
+kernfs_create_dir_ns(struct kernfs_node *parent, const char *name,
+		     umode_t mode, void *priv, const void *ns)
 { return ERR_PTR(-ENOSYS); }
 
 static inline struct kernfs_node *
@@ -314,9 +314,10 @@ kernfs_find_and_get(struct kernfs_node *kn, const char *name)
 }
 
 static inline struct kernfs_node *
-kernfs_create_dir(struct kernfs_node *parent, const char *name, void *priv)
+kernfs_create_dir(struct kernfs_node *parent, const char *name, umode_t mode,
+		  void *priv)
 {
-	return kernfs_create_dir_ns(parent, name, priv, NULL);
+	return kernfs_create_dir_ns(parent, name, mode, priv, NULL);
 }
 
 static inline struct kernfs_node *