Linus asks 'why "raid6" twice?'. No reason. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
		
			
				
	
	
		
			124 lines
		
	
	
	
		
			2.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
	
		
			2.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/* -*- linux-c -*- ------------------------------------------------------- *
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 *
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 *   Copyright 2002-2007 H. Peter Anvin - All Rights Reserved
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 *
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 *   This file is part of the Linux kernel, and is made available under
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 *   the terms of the GNU General Public License version 2 or (at your
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 *   option) any later version; incorporated herein by reference.
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 *
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 * ----------------------------------------------------------------------- */
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/*
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 * raid6test.c
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 *
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 * Test RAID-6 recovery with various algorithms
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 */
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <linux/raid/pq.h>
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#define NDISKS		16	/* Including P and Q */
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const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
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struct raid6_calls raid6_call;
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char *dataptrs[NDISKS];
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char data[NDISKS][PAGE_SIZE];
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char recovi[PAGE_SIZE], recovj[PAGE_SIZE];
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static void makedata(void)
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{
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	int i, j;
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	for (i = 0; i < NDISKS; i++) {
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		for (j = 0; j < PAGE_SIZE; j++)
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			data[i][j] = rand();
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		dataptrs[i] = data[i];
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	}
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}
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static char disk_type(int d)
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{
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	switch (d) {
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	case NDISKS-2:
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		return 'P';
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	case NDISKS-1:
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		return 'Q';
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	default:
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		return 'D';
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	}
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}
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static int test_disks(int i, int j)
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{
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	int erra, errb;
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	memset(recovi, 0xf0, PAGE_SIZE);
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	memset(recovj, 0xba, PAGE_SIZE);
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	dataptrs[i] = recovi;
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	dataptrs[j] = recovj;
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	raid6_dual_recov(NDISKS, PAGE_SIZE, i, j, (void **)&dataptrs);
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	erra = memcmp(data[i], recovi, PAGE_SIZE);
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	errb = memcmp(data[j], recovj, PAGE_SIZE);
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	if (i < NDISKS-2 && j == NDISKS-1) {
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		/* We don't implement the DQ failure scenario, since it's
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		   equivalent to a RAID-5 failure (XOR, then recompute Q) */
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		erra = errb = 0;
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	} else {
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		printf("algo=%-8s  faila=%3d(%c)  failb=%3d(%c)  %s\n",
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		       raid6_call.name,
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		       i, disk_type(i),
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		       j, disk_type(j),
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		       (!erra && !errb) ? "OK" :
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		       !erra ? "ERRB" :
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		       !errb ? "ERRA" : "ERRAB");
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	}
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	dataptrs[i] = data[i];
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	dataptrs[j] = data[j];
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	return erra || errb;
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}
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int main(int argc, char *argv[])
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{
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	const struct raid6_calls *const *algo;
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	int i, j;
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	int err = 0;
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	makedata();
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	for (algo = raid6_algos; *algo; algo++) {
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		if (!(*algo)->valid || (*algo)->valid()) {
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			raid6_call = **algo;
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			/* Nuke syndromes */
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			memset(data[NDISKS-2], 0xee, 2*PAGE_SIZE);
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			/* Generate assumed good syndrome */
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			raid6_call.gen_syndrome(NDISKS, PAGE_SIZE,
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						(void **)&dataptrs);
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			for (i = 0; i < NDISKS-1; i++)
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				for (j = i+1; j < NDISKS; j++)
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					err += test_disks(i, j);
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		}
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		printf("\n");
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	}
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	printf("\n");
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	/* Pick the best algorithm test */
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	raid6_select_algo();
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	if (err)
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		printf("\n*** ERRORS FOUND ***\n");
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	return err;
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}
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