int phys2log(int phys, int stripe, int n, int layout) { /* In an 'n' disk array using 'layout', * in stripe 'stripe', the physical disc 'phys' * stores what logical chunk? * -1 mean parity. * */ switch(layout) { case ALGORITHM_LEFT_ASYMMETRIC: pd = (n-1) - (stripe % n); if (phys < pd) return phys; else if (phys == pd) return -1; else return phys-1; case ALGORITHM_RIGHT_ASYMMETRIC: pd = stripe % n; if (phys < pd) return phys; else if (phys == pd) return -1; else return phys-1; case ALGORITHM_LEFT_SYMMETRIC: pd = (n-1) - (stripe %n); if (phys < pd) return phys+ n-1-pd; else if (phys == pd) return -1; else return phys-pd-1; case ALGORITHM_RIGHT_SYMMETRIC: pd = stripe % n; if (phys < pd) return phys+ n-1-pd; else if (phys == pd) return -1; else return phys-pd-1; } return -2; } raid5_extend(unsigned long len, int chunksize, int layout, int n, int m, int rfds[], int wfds[]) { static char buf[4096]; unsigned long blocks = len/4; unsigned int blocksperchunk= chunksize/4096; unsigned long b; for (b=0; b