fs/dcache.c: is_subdir can be boolean

This patch makes is_subdir return bool to improve
readability due to this particular function only using either
one or zero as its return value.

No functional change.
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/dcache.c

@@ -3303,18 +3303,18 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
  * @new_dentry: new dentry
  * @old_dentry: old dentry
  *
- * Returns 1 if new_dentry is a subdirectory of the parent (at any depth).
- * Returns 0 otherwise.
+ * Returns true if new_dentry is a subdirectory of the parent (at any depth).
+ * Returns false otherwise.
  * Caller must ensure that "new_dentry" is pinned before calling is_subdir()
  */
   
-int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
+bool is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
 {
-	int result;
+	bool result;
 	unsigned seq;
 
 	if (new_dentry == old_dentry)
-		return 1;
+		return true;
 
 	do {
 		/* for restarting inner loop in case of seq retry */
@@ -3325,9 +3325,9 @@ int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
 		 */
 		rcu_read_lock();
 		if (d_ancestor(old_dentry, new_dentry))
-			result = 1;
+			result = true;
 		else
-			result = 0;
+			result = false;
 		rcu_read_unlock();
 	} while (read_seqretry(&rename_lock, seq));
 

include/linux/fs.h

@@ -2532,7 +2532,7 @@ extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
 extern struct file * open_exec(const char *);
  
 /* fs/dcache.c -- generic fs support functions */
-extern int is_subdir(struct dentry *, struct dentry *);
+extern bool is_subdir(struct dentry *, struct dentry *);
 extern bool path_is_under(struct path *, struct path *);
 
 extern char *file_path(struct file *, char *, int);