/* * Copyright (C) 2013 Andrea Mazzoleni * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #ifndef __RAID_H #define __RAID_H /****************************************************************************/ /* raid */ /** * RAID mode supporting up to 6 parities. * * It requires SSSE3 to get good performance with triple or more * parities. * * This is the default mode used by SnapRAID. */ #define RAID_MODE_CAUCHY 0 /** * RAID mode supporting up to 3 parities, * * It has a fast triple parity implementation even without SSSE3, but it * cannot go beyond it. * This is mostly intended for low end CPUs like ARM and AMD Athlon. */ #define RAID_MODE_VANDERMONDE 1 /** * Max level of parity supported in the default mode RAID_MODE_CAUCHY. */ #define RAID_PARITY_MAX 6 /** * Maximum number of data disks. * Limit of the parity generator matrix used. */ #define RAID_DATA_MAX 251 /** * Initializes the RAID system. */ void raid_init(void); /** * Sets the mode to use. One of RAID_MODE_*. * * You can change mode at any time, and it will affect next calls to raid_par(), * raid_rec() and raid_recpar(). * * The two modes are compatible for the first two levels of parity. The third one * is different. */ void raid_mode(int mode); /** * Sets the zero buffer to use in recovering. * * Before calling raid_rec() and raid_recpar() you must provide a memory * buffer filled with zero with the same size of the blocks to recover. */ void raid_zero(void* zero); /** * Computes the parity. * * \param np Number of parities to compute. * \param nd Number of data disks. * \param size Size of the blocks pointed by vv. It must be a power of 2, and at least 64. * \param vv Vector of pointers to the blocks for disks and parities. * It has (::nd + ::np) elements. Each element points to a buffer of ::size bytes. */ void raid_par(int np, int nd, size_t size, void** vv); /** * Recovers failures of data disks using the specified parities. * * Only the data blocks are recovered. The parity buffers are destroyed. * If you want also to recompute parities, you can use raid_recpar(). * * \param nr Number of failed data disks to recover. * \param id[] Vector of ::nr indexes of the data disks to recover. Starting from 0. * \param ip[] Vector of ::nr indexes of the parity disks to use for recovering. Starting from 0. * \param nd Number of data disks. * \param size Size of the blocks pointed by vv. It must be a power of 2, and at least 64. * \param vv Vector of pointers to the blocks for disks and parities. * It has (::nd + ::ip[::nr - 1] + 1) elements. Each element points to a buffer of ::size bytes. */ void raid_rec(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); /** * Recovers failures of data and parity disks. * * It's similar at raid_rec() but it also recovers parities. * * In case there are more parities available than needed, ones to use are * automatically selected, excluding the ones specified in the ::ip vector. * * Ensure to have ::nrd + ::nrp <= ::np, otherwise recovering is not possible. * * \param nrd Number of failed data disks to recover. * \param id[] Vector of ::nrd indexes of the data disks to recover. Starting from 0. * \param nrp Number of failed parity disks to recover. * \param ip[] Vector of ::nrp indexes of the parity disks to recover. Starting from 0. * Note that as difference than raid_rec() these are the failed parities. * All the parities not specified here are assumed correct, and they are not recomputed. * \param np Number of parity disks. * \param nd Number of data disks. * \param size Size of the blocks pointed by vv. It must be a power of 2, and at least 64. * \param vv Vector of pointers to the blocks for disks and parities. * It has (::nd + ::np) elements. Each element points to a buffer of ::size bytes. */ void raid_recpar(int nrd, const int* id, int nrp, int* ip, int np, int nd, size_t size, void** vv); /** * Gets the name of the selected function to compute the parity. * Only for testing. */ const char* raid_par1_tag(void); const char* raid_par2_tag(void); const char* raid_parz_tag(void); const char* raid_par3_tag(void); const char* raid_par4_tag(void); const char* raid_par5_tag(void); const char* raid_par6_tag(void); const char* raid_rec1_tag(void); const char* raid_rec2_tag(void); const char* raid_recX_tag(void); /** * Specialized parity computation. * Only for testing. */ void raid_par1_int32(int nd, size_t size, void** vv); void raid_par1_int64(int nd, size_t size, void** vv); void raid_par1_sse2(int nd, size_t size, void** vv); void raid_par2_int32(int nd, size_t size, void** vv); void raid_par2_int64(int nd, size_t size, void** vv); void raid_par2_sse2(int nd, size_t size, void** vv); void raid_par2_sse2ext(int nd, size_t size, void** vv); void raid_parz_int32(int nd, size_t size, void** vv); void raid_parz_int64(int nd, size_t size, void** vv); void raid_parz_sse2(int nd, size_t size, void** vv); void raid_parz_sse2ext(int nd, size_t size, void** vv); void raid_par3_int8(int nd, size_t size, void** vv); void raid_par3_ssse3(int nd, size_t size, void** vv); void raid_par3_ssse3ext(int nd, size_t size, void** vv); void raid_par4_int8(int nd, size_t size, void** vv); void raid_par4_ssse3(int nd, size_t size, void** vv); void raid_par4_ssse3ext(int nd, size_t size, void** vv); void raid_par5_int8(int nd, size_t size, void** vv); void raid_par5_ssse3(int nd, size_t size, void** vv); void raid_par5_ssse3ext(int nd, size_t size, void** vv); void raid_par6_int8(int nd, size_t size, void** vv); void raid_par6_ssse3(int nd, size_t size, void** vv); void raid_par6_ssse3ext(int nd, size_t size, void** vv); void raid_rec1_int8(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); void raid_rec2_int8(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); void raid_recX_int8(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); void raid_rec1_ssse3(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); void raid_rec2_ssse3(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); void raid_recX_ssse3(int nr, const int* id, const int* ip, int nd, size_t size, void** vv); #endif