From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.cn.fujitsu.com ([183.91.158.132]:34826 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751047AbeAELR0 (ORCPT ); Fri, 5 Jan 2018 06:17:26 -0500 From: Gu Jinxiang To: CC: Qu Wenruo Subject: [v6 09/16] btrfs-progs: scrub: Introduce function to verify parities Date: Fri, 5 Jan 2018 19:01:17 +0800 Message-ID: <1515150084-17231-10-git-send-email-gujx@cn.fujitsu.com> In-Reply-To: <1515150084-17231-1-git-send-email-gujx@cn.fujitsu.com> References: <1515150084-17231-1-git-send-email-gujx@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: From: Qu Wenruo Introduce new function, verify_parities(), to check whether parities match with full stripe, whose data stripes match with their csum. Caller should fill the scrub_full_stripe structure properly before calling this function. Signed-off-by: Qu Wenruo Signed-off-by: Gu Jinxiang --- scrub.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/scrub.c b/scrub.c index 5c1c3957..3db82656 100644 --- a/scrub.c +++ b/scrub.c @@ -19,6 +19,7 @@ #include "disk-io.h" #include "utils.h" #include "kernel-lib/bitops.h" +#include "kernel-lib/raid56.h" /* * For parity based profile (RAID56) @@ -749,3 +750,71 @@ out: btrfs_free_path(path); return ret; } + +/* + * Verify parities for RAID56 + * Caller must fill @fstripe before calling this function + * + * Return 0 for parities matches. + * Return >0 for P or Q mismatch + * Return <0 for fatal error + */ +static int verify_parities(struct btrfs_fs_info *fs_info, + struct btrfs_scrub_progress *scrub_ctx, + struct scrub_full_stripe *fstripe) +{ + void **ptrs; + void *ondisk_p = NULL; + void *ondisk_q = NULL; + void *buf_p; + void *buf_q; + int nr_stripes = fstripe->nr_stripes; + int stripe_len = BTRFS_STRIPE_LEN; + int i; + int ret = 0; + + ptrs = malloc(sizeof(void *) * fstripe->nr_stripes); + buf_p = malloc(fstripe->stripe_len); + buf_q = malloc(fstripe->stripe_len); + if (!ptrs || !buf_p || !buf_q) { + ret = -ENOMEM; + goto out; + } + + for (i = 0; i < fstripe->nr_stripes; i++) { + struct scrub_stripe *stripe = &fstripe->stripes[i]; + + if (stripe->logical == BTRFS_RAID5_P_STRIPE) { + ondisk_p = stripe->data; + ptrs[i] = buf_p; + continue; + } else if (stripe->logical == BTRFS_RAID6_Q_STRIPE) { + ondisk_q = stripe->data; + ptrs[i] = buf_q; + continue; + } else { + ptrs[i] = stripe->data; + continue; + } + } + /* RAID6 */ + if (ondisk_q) { + raid6_gen_syndrome(nr_stripes, stripe_len, ptrs); + + if (memcmp(ondisk_q, ptrs[nr_stripes - 1], stripe_len) != 0 || + memcmp(ondisk_p, ptrs[nr_stripes - 2], stripe_len)) + ret = 1; + } else { + ret = raid5_gen_result(nr_stripes, stripe_len, nr_stripes - 1, + ptrs); + if (ret < 0) + goto out; + if (memcmp(ondisk_p, ptrs[nr_stripes - 1], stripe_len) != 0) + ret = 1; + } +out: + free(buf_p); + free(buf_q); + free(ptrs); + return ret; +} -- 2.14.3