test.c

Go to the documentation of this file.

/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright 2002-2007 H. Peter Anvin - All Rights Reserved
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2 or (at your
 *   option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * raid6test.c
 *
 * Test RAID-6 recovery with various algorithms
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <linux/raid/pq.h>

#define NDISKS      16  /* Including P and Q */

const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
struct raid6_calls raid6_call;

char *dataptrs[NDISKS];
char data[NDISKS][PAGE_SIZE];
char recovi[PAGE_SIZE], recovj[PAGE_SIZE];

static void makedata(void)
{
    int i, j;

    for (i = 0; i < NDISKS; i++) {
        for (j = 0; j < PAGE_SIZE; j++)
            data[i][j] = rand();

        dataptrs[i] = data[i];
    }
}

static char disk_type(int d)
{
    switch (d) {
    case NDISKS-2:
        return 'P';
    case NDISKS-1:
        return 'Q';
    default:
        return 'D';
    }
}

static int test_disks(int i, int j)
{
    int erra, errb;

    memset(recovi, 0xf0, PAGE_SIZE);
    memset(recovj, 0xba, PAGE_SIZE);

    dataptrs[i] = recovi;
    dataptrs[j] = recovj;

    raid6_dual_recov(NDISKS, PAGE_SIZE, i, j, (void **)&dataptrs);

    erra = memcmp(data[i], recovi, PAGE_SIZE);
    errb = memcmp(data[j], recovj, PAGE_SIZE);

    if (i < NDISKS-2 && j == NDISKS-1) {
        /* We don't implement the DQ failure scenario, since it's
           equivalent to a RAID-5 failure (XOR, then recompute Q) */
        erra = errb = 0;
    } else {
        printf("algo=%-8s  faila=%3d(%c)  failb=%3d(%c)  %s\n",
               raid6_call.name,
               i, disk_type(i),
               j, disk_type(j),
               (!erra && !errb) ? "OK" :
               !erra ? "ERRB" :
               !errb ? "ERRA" : "ERRAB");
    }

    dataptrs[i] = data[i];
    dataptrs[j] = data[j];

    return erra || errb;
}

int main(int argc, char *argv[])
{
    const struct raid6_calls *const *algo;
    const struct raid6_recov_calls *const *ra;
    int i, j;
    int err = 0;

    makedata();

    for (ra = raid6_recov_algos; *ra; ra++) {
        if ((*ra)->valid  && !(*ra)->valid())
            continue;
        raid6_2data_recov = (*ra)->data2;
        raid6_datap_recov = (*ra)->datap;

        printf("using recovery %s\n", (*ra)->name);

        for (algo = raid6_algos; *algo; algo++) {
            if (!(*algo)->valid || (*algo)->valid()) {
                raid6_call = **algo;

                /* Nuke syndromes */
                memset(data[NDISKS-2], 0xee, 2*PAGE_SIZE);

                /* Generate assumed good syndrome */
                raid6_call.gen_syndrome(NDISKS, PAGE_SIZE,
                            (void **)&dataptrs);

                for (i = 0; i < NDISKS-1; i++)
                    for (j = i+1; j < NDISKS; j++)
                        err += test_disks(i, j);
            }
        }
        printf("\n");
    }

    printf("\n");
    /* Pick the best algorithm test */
    raid6_select_algo();

    if (err)
        printf("\n*** ERRORS FOUND ***\n");

    return err;
}