diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index f9313f6845400f8880e870d77e385153ebe66bd1..3b095a35aa471c1cb22cacf90c948a0dd2073787 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -214,7 +214,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
  * Entry is guaranteed to be valid.
  */
 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
-			struct qstr *child, struct page **res_page)
+			const struct qstr *child, struct page **res_page)
 {
 	unsigned long npages = dir_blocks(dir);
 	struct f2fs_dir_entry *de = NULL;
@@ -277,7 +277,7 @@ struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
 	return de;
 }
 
-ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
+ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr)
 {
 	ino_t res = 0;
 	struct f2fs_dir_entry *de;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 916e7c238e3d14a9da4a91e965ff570d0dc91232..fd0a156d75614586d268d57a5a4838dc05f207d6 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1805,10 +1805,10 @@ struct page *init_inode_metadata(struct inode *, struct inode *,
 void update_parent_metadata(struct inode *, struct inode *, unsigned int);
 int room_for_filename(const void *, int, int);
 void f2fs_drop_nlink(struct inode *, struct inode *, struct page *);
-struct f2fs_dir_entry *f2fs_find_entry(struct inode *, struct qstr *,
+struct f2fs_dir_entry *f2fs_find_entry(struct inode *, const struct qstr *,
 							struct page **);
 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *, struct page **);
-ino_t f2fs_inode_by_name(struct inode *, struct qstr *);
+ino_t f2fs_inode_by_name(struct inode *, const struct qstr *);
 void f2fs_set_link(struct inode *, struct f2fs_dir_entry *,
 				struct page *, struct inode *);
 int update_dent_inode(struct inode *, struct inode *, const struct qstr *);