snapraid/raid.h

178 lines
6.7 KiB
C

/*
* 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 <http://www.gnu.org/licenses/>.
*/
#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