chapter191, [SORA] About Blockchain mini filesystem structure, part2

We implemented a buffer that can be accumulated from the mock beginning sector number and the number of read sectors.

bool_t fs_disk_open(FSDISK **fdp);
Open by FSDISK in pointer.

bool_t fs_disk_close(FSDISK *fdp, bool_t ret);
Close by FSDISK in pointer.

bool_t fs_disk_read(FSDISK *fdp, sector_t begin, counter_t num, byte_t *buf);
Pass FSDISK and buffer, read in sector units.

bool_t fs_disk_write(FSDISK *fdp, sector_t begin, counter_t num, const byte_t *buf);
Pass FSDISK and const buffer, write in sector units.