fprintf(stderr, "\t-s|--sectorsize SIZE min block allocation (may not mountable by current kernel)\n");
fprintf(stderr, "\t-r|--rootdir DIR the source directory\n");
fprintf(stderr, "\t-K|--nodiscard do not perform whole device TRIM\n");
- fprintf(stderr, "\t-O|--features LIST comma separated list of filesystem features\n");
+ fprintf(stderr, "\t-O|--features LIST comma separated list of filesystem features, use '-O list-all' to list features\n");
fprintf(stderr, "\t-U|--uuid UUID specify the filesystem UUID\n");
fprintf(stderr, "\t-V|--version print the mkfs.btrfs version and exit\n");
fprintf(stderr, "%s\n", PACKAGE_STRING);