From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:19150 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751705AbbEKAsA (ORCPT ); Sun, 10 May 2015 20:48:00 -0400 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t4B0kTW2031696 for ; Mon, 11 May 2015 08:46:30 +0800 From: Qu Wenruo To: Subject: [PATCH 1/2] btrfs-progs: Fix a bug in __btrfs_map_block() always maps wrong stripe for DUP/RAID1 Date: Mon, 11 May 2015 08:45:47 +0800 Message-ID: <1431305148-18953-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: In __btrfs_map_block(), stripe_index is always wrong if mirror_num is given. For DUP/RAID1 case, if mirror_num is given, e.g. 1, it should return the second stripe. But codes consider the mirror_num is start from 1 and always minus 1, causing even mirror number is given as 1, __btrfs_map_block() will still map the first stripe not the second. Signed-off-by: Qu Wenruo --- volumes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/volumes.c b/volumes.c index 16dbf64..c66c02a 100644 --- a/volumes.c +++ b/volumes.c @@ -1397,7 +1397,7 @@ again: if (rw == WRITE) multi->num_stripes = map->num_stripes; else if (mirror_num) - stripe_index = mirror_num - 1; + stripe_index = mirror_num; else stripe_index = stripe_nr % map->num_stripes; } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { @@ -1416,7 +1416,7 @@ again: if (rw == WRITE) multi->num_stripes = map->num_stripes; else if (mirror_num) - stripe_index = mirror_num - 1; + stripe_index = mirror_num; } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) { -- 2.4.0