mirror of
https://github.com/torvalds/linux.git
synced 2026-07-27 09:36:22 +02:00
30bf04bd13
Drop the pointless mention of the file name, and use standard formatting for the top of file comments. Link: https://lore.kernel.org/20260518051804.462141-14-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Ard Biesheuvel <ardb@kernel.org> # kunit only on arm64 Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Mason <clm@fb.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Sterba <dsterba@suse.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Nan <linan122@huawei.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Song Liu <song@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
96 lines
2.4 KiB
C
96 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright 2002 H. Peter Anvin - All Rights Reserved
|
|
*
|
|
* 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/mm.h>
|
|
#include <linux/raid/pq.h>
|
|
#include "algos.h"
|
|
|
|
/* Recover two failed data blocks. */
|
|
static void raid6_2data_recov_intx1(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] = page_address(ZERO_PAGE(0));
|
|
ptrs[disks-2] = dp;
|
|
dq = (u8 *)ptrs[failb];
|
|
ptrs[failb] = page_address(ZERO_PAGE(0));
|
|
ptrs[disks-1] = dq;
|
|
|
|
raid6_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++;
|
|
}
|
|
}
|
|
|
|
/* Recover failure of one data block plus the P block */
|
|
static void raid6_datap_recov_intx1(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] = page_address(ZERO_PAGE(0));
|
|
ptrs[disks-1] = dq;
|
|
|
|
raid6_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++;
|
|
}
|
|
}
|
|
|
|
|
|
const struct raid6_recov_calls raid6_recov_intx1 = {
|
|
.data2 = raid6_2data_recov_intx1,
|
|
.datap = raid6_datap_recov_intx1,
|
|
.name = "intx1",
|
|
};
|