From patchwork Mon Mar 31 10:34:03 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Shilong X-Patchwork-Id: 3913271 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 528A59F2B6 for ; Mon, 31 Mar 2014 10:36:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6C1B22020F for ; Mon, 31 Mar 2014 10:36:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F2082020A for ; Mon, 31 Mar 2014 10:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753570AbaCaKg3 (ORCPT ); Mon, 31 Mar 2014 06:36:29 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:57038 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751689AbaCaKg2 (ORCPT ); Mon, 31 Mar 2014 06:36:28 -0400 X-IronPort-AV: E=Sophos;i="4.97,763,1389715200"; d="scan'208";a="9800047" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 31 Mar 2014 18:32:32 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id s2VAaPIE031727 for ; Mon, 31 Mar 2014 18:36:25 +0800 Received: from wangs.fnst.cn.fujitsu.com ([10.167.226.104]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2014033118331035-870991 ; Mon, 31 Mar 2014 18:33:10 +0800 From: Wang Shilong To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 2/2] Btrfs: scrub raid56 stripes in the right way Date: Mon, 31 Mar 2014 18:34:03 +0800 Message-Id: <1396262043-10304-1-git-send-email-wangsl.fnst@cn.fujitsu.com> X-Mailer: git-send-email 1.9.0 X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2014/03/31 18:33:10, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2014/03/31 18:33:11, Serialize complete at 2014/03/31 18:33:11 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Steps to reproduce: # mkfs.btrfs -f /dev/sda[8-11] -m raid5 -d raid5 # mount /dev/sda8 /mnt # btrfs scrub start -BR /mnt # echo $? <--unverified errors make return value be 3 This is because we don't setup right mapping between physical and logical address for raid56, which makes checksum mismatch. But we will find everthing is fine later when rechecking using btrfs_map_block(). This patch fixed the problem by settuping right mappings and we only verify data stripes' checksums. Signed-off-by: Wang Shilong --- v1->v2: on the right way to fix the problem. --- fs/btrfs/scrub.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 71 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index db21a13..ebe4c5e 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2235,6 +2235,43 @@ behind_scrub_pages: return 0; } +/* + * Given a physical address, this will calculate it's + * logical offset. if this is a parity stripe, it will return + * the most left data stripe's logical offset. + * + * return 0 if it is a data stripe, 1 means parity stripe. + */ +static int get_raid56_logic_offset(u64 physical, int num, + struct map_lookup *map, u64 *offset) +{ + int i; + int j = 0; + u64 stripe_nr; + u64 tmp; + u64 last_offset; + int stripe_index; + + last_offset = (physical - map->stripes[num].physical) * + nr_data_stripes(map); + *offset = last_offset; + for (i = 0; i < nr_data_stripes(map); i++) { + *offset += i * map->stripe_len; + stripe_nr = *offset; + do_div(stripe_nr, map->stripe_len); + + stripe_index = do_div(stripe_nr, nr_data_stripes(map)); + tmp = stripe_nr + stripe_index; + stripe_index = do_div(tmp, map->num_stripes); + if (stripe_index == num) + return 0; + if (stripe_index < num) + j++; + } + *offset = last_offset + j * map->stripe_len; + return 1; +} + static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, struct map_lookup *map, struct btrfs_device *scrub_dev, @@ -2269,16 +2306,10 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, u64 extent_len; struct btrfs_device *extent_dev; int extent_mirror_num; - int stop_loop; - - if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | - BTRFS_BLOCK_GROUP_RAID6)) { - if (num >= nr_data_stripes(map)) { - return 0; - } - } + int stop_loop = 0; nstripes = length; + physical = map->stripes[num].physical; offset = 0; do_div(nstripes, map->stripe_len); if (map->type & BTRFS_BLOCK_GROUP_RAID0) { @@ -2296,6 +2327,11 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { increment = map->stripe_len; mirror_num = num % map->num_stripes + 1; + } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6)) { + get_raid56_logic_offset(physical, num, map, &offset); + increment = map->stripe_len * nr_data_stripes(map); + mirror_num = 1; } else { increment = map->stripe_len; mirror_num = 1; @@ -2357,10 +2393,18 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, * now find all extents for each stripe and scrub them */ logical = base + offset; - physical = map->stripes[num].physical; logic_end = logical + increment * nstripes; ret = 0; while (logical < logic_end) { + /* for raid56, we skip parity stripe */ + if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6)) { + ret = get_raid56_logic_offset(physical, num, + map, &logical); + logical += base; + if (ret) + goto skip; + } /* * canceled? */ @@ -2504,9 +2548,23 @@ again: scrub_free_csums(sctx); if (extent_logical + extent_len < key.objectid + bytes) { - logical += increment; - physical += map->stripe_len; - + if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6)) { + /* + * loop until we find next data stripe + * or we have finished all stripes. + */ + do { + physical += map->stripe_len; + ret = get_raid56_logic_offset( + physical, num, + map, &logical); + logical += base; + } while (logical < logic_end && ret); + } else { + physical += map->stripe_len; + logical += increment; + } if (logical < key.objectid + bytes) { cond_resched(); goto again; @@ -2521,6 +2579,7 @@ next: path->slots[0]++; } btrfs_release_path(path); +skip: logical += increment; physical += map->stripe_len; spin_lock(&sctx->stat_lock);