md: Factor out RAID6 algorithms into lib/

We'll want to use these in btrfs too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 0 insertions, 132 deletions

diff --git a/drivers/md/raid6recov.c b/drivers/md/raid6recov.c
deleted file mode 100644
index 2609f00e0d6..00000000000
--- a/drivers/md/raid6recov.c
+++ /dev/null
@@ -1,132 +0,0 @@
-/* -*- linux-c -*- ------------------------------------------------------- *
- *
- *   Copyright 2002 H. Peter Anvin - All Rights Reserved
- *
- *   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, Inc., 53 Temple Place Ste 330,
- *   Boston MA 02111-1307, USA; either version 2 of the License, or
- *   (at your option) any later version; incorporated herein by reference.
- *
- * ----------------------------------------------------------------------- */
-
-/*
- * raid6recov.c
- *
- * RAID-6 data recovery in dual failure mode.  In single failure mode,
- * use the RAID-5 algorithm (or, in the case of Q failure, just reconstruct
- * the syndrome.)
- */
-
-#include <linux/raid/pq.h>
-
-/* Recover two failed data blocks. */
-void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
-		       void **ptrs)
-{
-	u8 *p, *q, *dp, *dq;
-	u8 px, qx, db;
-	const u8 *pbmul;	/* P multiplier table for B data */
-	const u8 *qmul;		/* Q multiplier table (for both) */
-
-	p = (u8 *)ptrs[disks-2];
-	q = (u8 *)ptrs[disks-1];
-
-	/* Compute syndrome with zero for the missing data pages
-	   Use the dead data pages as temporary storage for
-	   delta p and delta q */
-	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
-	ptrs[disks-2] = dp;
-	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
-	ptrs[disks-1] = dq;
-
-	raid6_call.gen_syndrome(disks, bytes, ptrs);
-
-	/* Restore pointer table */
-	ptrs[faila]   = dp;
-	ptrs[failb]   = dq;
-	ptrs[disks-2] = p;
-	ptrs[disks-1] = q;
-
-	/* Now, pick the proper data tables */
-	pbmul = raid6_gfmul[raid6_gfexi[failb-faila]];
-	qmul  = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]];
-
-	/* Now do it... */
-	while ( bytes-- ) {
-		px    = *p ^ *dp;
-		qx    = qmul[*q ^ *dq];
-		*dq++ = db = pbmul[px] ^ qx; /* Reconstructed B */
-		*dp++ = db ^ px; /* Reconstructed A */
-		p++; q++;
-	}
-}
-EXPORT_SYMBOL_GPL(raid6_2data_recov);
-
-/* Recover failure of one data block plus the P block */
-void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs)
-{
-	u8 *p, *q, *dq;
-	const u8 *qmul;		/* Q multiplier table */
-
-	p = (u8 *)ptrs[disks-2];
-	q = (u8 *)ptrs[disks-1];
-
-	/* Compute syndrome with zero for the missing data page
-	   Use the dead data page as temporary storage for delta q */
-	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
-	ptrs[disks-1] = dq;
-
-	raid6_call.gen_syndrome(disks, bytes, ptrs);
-
-	/* Restore pointer table */
-	ptrs[faila]   = dq;
-	ptrs[disks-1] = q;
-
-	/* Now, pick the proper data tables */
-	qmul  = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]]];
-
-	/* Now do it... */
-	while ( bytes-- ) {
-		*p++ ^= *dq = qmul[*q ^ *dq];
-		q++; dq++;
-	}
-}
-EXPORT_SYMBOL_GPL(raid6_datap_recov);
-
-#ifndef __KERNEL__
-/* Testing only */
-
-/* Recover two failed blocks. */
-void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs)
-{
-	if ( faila > failb ) {
-		int tmp = faila;
-		faila = failb;
-		failb = tmp;
-	}
-
-	if ( failb == disks-1 ) {
-		if ( faila == disks-2 ) {
-			/* P+Q failure.  Just rebuild the syndrome. */
-			raid6_call.gen_syndrome(disks, bytes, ptrs);
-		} else {
-			/* data+Q failure.  Reconstruct data from P,
-			   then rebuild syndrome. */
-			/* NOT IMPLEMENTED - equivalent to RAID-5 */
-		}
-	} else {
-		if ( failb == disks-2 ) {
-			/* data+P failure. */
-			raid6_datap_recov(disks, bytes, faila, ptrs);
-		} else {
-			/* data+data failure. */
-			raid6_2data_recov(disks, bytes, faila, failb, ptrs);
-		}
-	}
-}
-
-#endif