ext4: correct encrypted dentry name hash when not casefolded

EXT4_DIRENT_HASH and EXT4_DIRENT_MINOR_HASH will access struct
ext4_dir_entry_hash followed ext4_dir_entry. But there is no ext4_dir_entry_hash
followed when inode is encrypted and not casefolded

Signed-off-by: yao.ly <yao.ly@linux.alibaba.com>
Link: https://patch.msgid.link/1719816219-128287-1-git-send-email-yao.ly@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

fs/ext4/dir.c

@@ -279,12 +279,20 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 					struct fscrypt_str de_name =
 							FSTR_INIT(de->name,
 								de->name_len);
+					u32 hash;
+					u32 minor_hash;
+
+					if (IS_CASEFOLDED(inode)) {
+						hash = EXT4_DIRENT_HASH(de);
+						minor_hash = EXT4_DIRENT_MINOR_HASH(de);
+					} else {
+						hash = 0;
+						minor_hash = 0;
+					}
 
 					/* Directory is encrypted */
 					err = fscrypt_fname_disk_to_usr(inode,
-						EXT4_DIRENT_HASH(de),
-						EXT4_DIRENT_MINOR_HASH(de),
-						&de_name, &fstr);
+						hash, minor_hash, &de_name, &fstr);
 					de_name = fstr;
 					fstr.len = save_len;
 					if (err)