fs/ntfs3: Add iocharset= mount option as alias for nls=

Other fs drivers are using iocharset= mount option for specifying charset.
So add it also for ntfs3 and mark old nls= mount option as deprecated.

Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 729ead6..503e2e2 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -226,7 +226,7 @@ enum Opt {
 	Opt_nohidden,
 	Opt_showmeta,
 	Opt_acl,
-	Opt_nls,
+	Opt_iocharset,
 	Opt_prealloc,
 	Opt_no_acs_rules,
 	Opt_err,
@@ -245,9 +245,13 @@ static const struct fs_parameter_spec ntfs_fs_parameters[] = {
 	fsparam_flag_no("hidden",		Opt_nohidden),
 	fsparam_flag_no("acl",			Opt_acl),
 	fsparam_flag_no("showmeta",		Opt_showmeta),
-	fsparam_string("nls",			Opt_nls),
 	fsparam_flag_no("prealloc",		Opt_prealloc),
 	fsparam_flag("no_acs_rules",		Opt_no_acs_rules),
+	fsparam_string("iocharset",		Opt_iocharset),
+
+	__fsparam(fs_param_is_string,
+		  "nls", Opt_iocharset,
+		  fs_param_deprecated, NULL),
 	{}
 };
 
@@ -346,7 +350,7 @@ static int ntfs_fs_parse_param(struct fs_context *fc,
 	case Opt_showmeta:
 		opts->showmeta = result.negated ? 0 : 1;
 		break;
-	case Opt_nls:
+	case Opt_iocharset:
 		kfree(opts->nls_name);
 		opts->nls_name = param->string;
 		param->string = NULL;
@@ -380,11 +384,11 @@ static int ntfs_fs_reconfigure(struct fs_context *fc)
 	new_opts->nls = ntfs_load_nls(new_opts->nls_name);
 	if (IS_ERR(new_opts->nls)) {
 		new_opts->nls = NULL;
-		errorf(fc, "ntfs3: Cannot load nls %s", new_opts->nls_name);
+		errorf(fc, "ntfs3: Cannot load iocharset %s", new_opts->nls_name);
 		return -EINVAL;
 	}
 	if (new_opts->nls != sbi->options->nls)
-		return invalf(fc, "ntfs3: Cannot use different nls when remounting!");
+		return invalf(fc, "ntfs3: Cannot use different iocharset when remounting!");
 
 	sync_filesystem(sb);
 
@@ -528,9 +532,9 @@ static int ntfs_show_options(struct seq_file *m, struct dentry *root)
 	if (opts->dmask)
 		seq_printf(m, ",dmask=%04o", ~opts->fs_dmask_inv);
 	if (opts->nls)
-		seq_printf(m, ",nls=%s", opts->nls->charset);
+		seq_printf(m, ",iocharset=%s", opts->nls->charset);
 	else
-		seq_puts(m, ",nls=utf8");
+		seq_puts(m, ",iocharset=utf8");
 	if (opts->sys_immutable)
 		seq_puts(m, ",sys_immutable");
 	if (opts->discard)