[PATCH 4/6] fsconfig: parse "subtype" param for old internal API

[Miklos Szeredi <mszeredi@redhat.com>]

This subtype thing is specific to "fuse" and "fuseblk" filesystems.  When these
are switched over to the new context API, the handling of this parameter can be
moved from legacy_parse_param() into fuse.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
 fs/fs_context.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/fs/fs_context.c b/fs/fs_context.c
index c0ecbb1ecdfe..0192456712d2 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -574,6 +574,16 @@ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		param->string = NULL;
 		return 0;
 	}
+	if ((fc->fs_type->fs_flags & FS_HAS_SUBTYPE) &&
+	    strcmp(param->key, "subtype") == 0) {
+		if (param->type != fs_value_is_string)
+			return invalf(fc, "VFS: Legacy: Non-string subtype");
+		if (fc->subtype)
+			return invalf(fc, "VFS: Legacy: Multiple subtype");
+		fc->subtype = param->string;
+		param->string= NULL;
+		return 0;
+	}
 
 	if (ctx->param_type != LEGACY_FS_UNSET_PARAMS &&
 	    ctx->param_type != LEGACY_FS_INDIVIDUAL_PARAMS)
-- 
2.14.3