bcachefs: BCH_ERR_opt_parse_error

Continuing the project of replacing generic error codes with more
specific ones.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/errcode.h

@@ -175,6 +175,7 @@
 	x(EINVAL,			insufficient_devices_to_start)		\
 	x(EINVAL,			invalid)				\
 	x(EINVAL,			internal_fsck_err)			\
+	x(EINVAL,			opt_parse_error)			\
 	x(EROFS,			erofs_trans_commit)			\
 	x(EROFS,			erofs_no_writes)			\
 	x(EROFS,			erofs_journal_err)			\

fs/bcachefs/opts.c

@@ -279,14 +279,14 @@ int bch2_opt_validate(const struct bch_option *opt, u64 v, struct printbuf *err)
 		if (err)
 			prt_printf(err, "%s: not a multiple of 512",
 			       opt->attr.name);
-		return -EINVAL;
+		return -BCH_ERR_opt_parse_error;
 	}
 
 	if ((opt->flags & OPT_MUST_BE_POW_2) && !is_power_of_2(v)) {
 		if (err)
 			prt_printf(err, "%s: must be a power of two",
 			       opt->attr.name);
-		return -EINVAL;
+		return -BCH_ERR_opt_parse_error;
 	}
 
 	if (opt->fn.validate)