hfsplus: fix option parsing during remount

hfsplus only actually uses the force option during remount, but it uses
the full option parser with a fake superblock to do so.  This means remount
will fail if any nls option is set (which happens frequently with older
mount tools), even if it is the same.

Fix this by adding a simpler version of the parser that only parses the force
option for remount.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index f9ab276a4d8d..43b02b5525eb 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -65,6 +65,32 @@ static inline int match_fourchar(substring_t *arg, u32 *result)
 	return 0;
 }
 
+int hfsplus_parse_options_remount(char *input, int *force)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int token;
+
+	if (!input)
+		return 0;
+
+	while ((p = strsep(&input, ",")) != NULL) {
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case opt_force:
+			*force = 1;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return 1;
+}
+
 /* Parse options from mount. Returns 0 on failure */
 /* input is the options passed to mount() as a string */
 int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)