fsnotify: use unsigned char * for dentry->d_name.name

fsnotify was using char * when it passed around the d_name.name string
internally but it is actually an unsigned char *. This patch switches
fsnotify to use unsigned and should silence some pointer signess warnings
which have popped out of xfs. I do not add -Wpointer-sign to the fsnotify
code as there are still issues with kstrdup and strlen which would pop
out needless warnings.

Signed-off-by: Eric Paris <[e-mail]>

fs/namei.c

···
 {
 	int error;
 	int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
-	const char *old_name;
+	const unsigned char *old_name;
 
 	if (old_dentry->d_inode == new_dentry->d_inode)
  		return 0;

fs/notify/fsnotify.c

···
 
 static void send_to_group(struct fsnotify_group *group, struct inode *to_tell,
 			  struct vfsmount *mnt, __u32 mask, void *data,
-			  int data_is, u32 cookie, const char *file_name,
+			  int data_is, u32 cookie, const unsigned char *file_name,
 			  struct fsnotify_event **event)
 {
 	if (!group->ops->should_send_event(group, to_tell, mnt, mask,
···
  * out to all of the registered fsnotify_group.  Those groups can then use the
  * notification event in whatever means they feel necessary.
  */
-void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name, u32 cookie)
+void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
+	      const unsigned char *file_name, u32 cookie)
 {
 	struct fsnotify_group *group;
 	struct fsnotify_event *event = NULL;

fs/notify/notification.c

···
  * @name the filename, if available
  */
 struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data,
-					     int data_type, const char *name, u32 cookie,
-					     gfp_t gfp)
+					     int data_type, const unsigned char *name,
+					     u32 cookie, gfp_t gfp)
 {
 	struct fsnotify_event *event;
 

include/linux/fsnotify.h

···
  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  */
 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
-				 const char *old_name,
+				 const unsigned char *old_name,
 				 int isdir, struct inode *target, struct dentry *moved)
 {
 	struct inode *source = moved->d_inode;
 	u32 fs_cookie = fsnotify_get_cookie();
 	__u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
 	__u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
-	const char *new_name = moved->d_name.name;
+	const unsigned char *new_name = moved->d_name.name;
 
 	if (old_dir == new_dir)
 		old_dir_mask |= FS_DN_RENAME;
···
 /*
  * fsnotify_oldname_init - save off the old filename before we change it
  */
-static inline const char *fsnotify_oldname_init(const char *name)
+static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
 {
 	return kstrdup(name, GFP_KERNEL);
 }
···
 /*
  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
  */
-static inline void fsnotify_oldname_free(const char *old_name)
+static inline void fsnotify_oldname_free(const unsigned char *old_name)
 {
 	kfree(old_name);
 }
 
 #else	/* CONFIG_FSNOTIFY */
 
-static inline const char *fsnotify_oldname_init(const char *name)
+static inline const char *fsnotify_oldname_init(const unsigned char *name)
 {
 	return NULL;
 }
 
-static inline void fsnotify_oldname_free(const char *old_name)
+static inline void fsnotify_oldname_free(const unsigned char *old_name)
 {
 }
 

include/linux/fsnotify_backend.h

···
 	__u32 mask;		/* the type of access, bitwise OR for FS_* event types */
 
 	u32 sync_cookie;	/* used to corrolate events, namely inotify mv events */
-	char *file_name;
+	const unsigned char *file_name;
 	size_t name_len;
 	struct pid *tgid;
 
···
 
 /* main fsnotify call to send events */
 extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
-		     const char *name, u32 cookie);
+		     const unsigned char *name, u32 cookie);
 extern void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask);
 extern void __fsnotify_inode_delete(struct inode *inode);
 extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
···
 
 /* put here because inotify does some weird stuff when destroying watches */
 extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
-						    void *data, int data_is, const char *name,
+						    void *data, int data_is,
+						    const unsigned char *name,
 						    u32 cookie, gfp_t gfp);
 
 /* fanotify likes to change events after they are on lists... */
···
 #else
 
 static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
-			    const char *name, u32 cookie)
+			    const unsigned char *name, u32 cookie)
 {}
 
 static inline void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)