fscrypt: remove unneeded empty fscrypt_operations structs

In the case where a filesystem has been configured without encryption
support, there is no longer any need to initialize ->s_cop at all, since
none of the methods are ever called.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Acked-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

fs/ext4/super.c

@@ -1244,9 +1244,6 @@ static const struct fscrypt_operations ext4_cryptops = {
 	.empty_dir		= ext4_empty_dir,
 	.max_namelen		= ext4_max_namelen,
 };
-#else
-static const struct fscrypt_operations ext4_cryptops = {
-};
 #endif
 
 #ifdef CONFIG_QUOTA
@@ -3998,7 +3995,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_op = &ext4_sops;
 	sb->s_export_op = &ext4_export_ops;
 	sb->s_xattr = ext4_xattr_handlers;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
 	sb->s_cop = &ext4_cryptops;
+#endif
 #ifdef CONFIG_QUOTA
 	sb->dq_op = &ext4_quota_operations;
 	if (ext4_has_feature_quota(sb))

fs/f2fs/super.c

@@ -1597,9 +1597,6 @@ static const struct fscrypt_operations f2fs_cryptops = {
 	.empty_dir	= f2fs_empty_dir,
 	.max_namelen	= f2fs_max_namelen,
 };
-#else
-static const struct fscrypt_operations f2fs_cryptops = {
-};
 #endif
 
 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
@@ -2318,7 +2315,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 #endif
 
 	sb->s_op = &f2fs_sops;
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
 	sb->s_cop = &f2fs_cryptops;
+#endif
 	sb->s_xattr = f2fs_xattr_handlers;
 	sb->s_export_op = &f2fs_export_ops;
 	sb->s_magic = F2FS_SUPER_MAGIC;

fs/ubifs/super.c

@@ -2007,11 +2007,6 @@ static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
 	return c;
 }
 
-#ifndef CONFIG_UBIFS_FS_ENCRYPTION
-const struct fscrypt_operations ubifs_crypt_operations = {
-};
-#endif
-
 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct ubifs_info *c = sb->s_fs_info;
@@ -2054,7 +2049,9 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
 		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
 	sb->s_op = &ubifs_super_operations;
 	sb->s_xattr = ubifs_xattr_handlers;
+#ifdef CONFIG_UBIFS_FS_ENCRYPTION
 	sb->s_cop = &ubifs_crypt_operations;
+#endif
 
 	mutex_lock(&c->umount_mutex);
 	err = mount_ubifs(c);