From patchwork Mon Dec 26 06:29:23 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 9488511 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C135462AAD for ; Mon, 26 Dec 2016 06:30:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B28231FFCA for ; Mon, 26 Dec 2016 06:30:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A774A2022C; Mon, 26 Dec 2016 06:30:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3A874201F3 for ; Mon, 26 Dec 2016 06:30:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755066AbcLZGag (ORCPT ); Mon, 26 Dec 2016 01:30:36 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:2344 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754994AbcLZGaY (ORCPT ); Mon, 26 Dec 2016 01:30:24 -0500 X-IronPort-AV: E=Sophos;i="5.20,367,1444665600"; d="scan'208";a="1036578" Received: from unknown (HELO cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 26 Dec 2016 14:29:47 +0800 Received: from localhost.localdomain (unknown [10.167.226.34]) by cn.fujitsu.com (Postfix) with ESMTP id 0708441B4BD3 for ; Mon, 26 Dec 2016 14:29:42 +0800 (CST) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 03/19] btrfs-progs: raid56: Allow raid6 to recover 2 data stripes Date: Mon, 26 Dec 2016 14:29:23 +0800 Message-Id: <20161226062939.5841-4-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20161226062939.5841-1-quwenruo@cn.fujitsu.com> References: <20161226062939.5841-1-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: 0708441B4BD3.AC16C X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: quwenruo@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Copied from kernel lib/raid6/recov.c raid6_2data_recov_intx1() function. With the following modification: - Rename to raid6_recov_data2() for shorter name - s/kfree/free/g modification Signed-off-by: Qu Wenruo --- Makefile.in | 4 +-- raid56.c => kernel-lib/raid56.c | 69 +++++++++++++++++++++++++++++++++++++++++ kernel-lib/raid56.h | 5 +++ 3 files changed, 76 insertions(+), 2 deletions(-) rename raid56.c => kernel-lib/raid56.c (71%) diff --git a/Makefile.in b/Makefile.in index fecaaa6a..c3f0eeda 100644 --- a/Makefile.in +++ b/Makefile.in @@ -96,10 +96,10 @@ CHECKER_FLAGS := -include $(check_defs) -D__CHECKER__ \ objects = ctree.o disk-io.o kernel-lib/radix-tree.o extent-tree.o print-tree.o \ root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \ extent-cache.o extent_io.o volumes.o utils.o repair.o \ - qgroup.o raid56.o free-space-cache.o kernel-lib/list_sort.o props.o \ + qgroup.o free-space-cache.o kernel-lib/list_sort.o props.o \ ulist.o qgroup-verify.o backref.o string-table.o task-utils.o \ inode.o file.o find-root.o free-space-tree.o help.o send-dump.o \ - kernel-lib/tables.o + kernel-lib/tables.o kernel-lib/raid56.o cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \ cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \ cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \ diff --git a/raid56.c b/kernel-lib/raid56.c similarity index 71% rename from raid56.c rename to kernel-lib/raid56.c index 8c79c456..dca8f8d4 100644 --- a/raid56.c +++ b/kernel-lib/raid56.c @@ -28,6 +28,7 @@ #include "disk-io.h" #include "volumes.h" #include "utils.h" +#include "kernel-lib/raid56.h" /* * This is the C data type to use @@ -170,3 +171,71 @@ int raid5_gen_result(int nr_devs, size_t stripe_len, int dest, void **data) } return 0; } + +/* + * Raid 6 recovery code copied from kernel lib/raid6/recov.c. + * With modifications: + * - rename from raid6_2data_recov_intx1 + * - kfree/free modification for btrfs-progs + */ +int raid6_recov_data2(int nr_devs, size_t stripe_len, int dest1, int dest2, + void **data) +{ + 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) */ + char *zero_mem1, *zero_mem2; + int ret = 0; + + /* Early check */ + if (dest1 < 0 || dest1 >= nr_devs - 2 || + dest2 < 0 || dest2 >= nr_devs - 2 || dest1 >= dest2) + return -EINVAL; + + zero_mem1 = calloc(1, stripe_len); + zero_mem2 = calloc(1, stripe_len); + if (!zero_mem1 || !zero_mem2) { + free(zero_mem1); + free(zero_mem2); + return -ENOMEM; + } + + p = (u8 *)data[nr_devs - 2]; + q = (u8 *)data[nr_devs - 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 *)data[dest1]; + data[dest1] = (void *)zero_mem1; + data[nr_devs - 2] = dp; + dq = (u8 *)data[dest2]; + data[dest2] = (void *)zero_mem2; + data[nr_devs - 1] = dq; + + raid6_gen_syndrome(nr_devs, stripe_len, data); + + /* Restore pointer table */ + data[dest1] = dp; + data[dest2] = dq; + data[nr_devs - 2] = p; + data[nr_devs - 1] = q; + + /* Now, pick the proper data tables */ + pbmul = raid6_gfmul[raid6_gfexi[dest2 - dest1]]; + qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[dest1]^raid6_gfexp[dest2]]]; + + /* Now do it... */ + while ( stripe_len-- ) { + px = *p ^ *dp; + qx = qmul[*q ^ *dq]; + *dq++ = db = pbmul[px] ^ qx; /* Reconstructed B */ + *dp++ = db ^ px; /* Reconstructed A */ + p++; q++; + } + + free(zero_mem1); + free(zero_mem2); + return ret; +} diff --git a/kernel-lib/raid56.h b/kernel-lib/raid56.h index 1bf2e01a..d397a23e 100644 --- a/kernel-lib/raid56.h +++ b/kernel-lib/raid56.h @@ -37,4 +37,9 @@ extern const u8 raid6_vgfmul[256][32] __attribute__((aligned(256))); extern const u8 raid6_gfexp[256] __attribute__((aligned(256))); extern const u8 raid6_gfinv[256] __attribute__((aligned(256))); extern const u8 raid6_gfexi[256] __attribute__((aligned(256))); + + +/* Recover raid6 with 2 data corrupted */ +int raid6_recov_data2(int nr_devs, size_t stripe_len, int dest1, int dest2, + void **data); #endif