From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.cn.fujitsu.com ([183.91.158.132]:54936 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751329AbdJSBtd (ORCPT ); Wed, 18 Oct 2017 21:49:33 -0400 From: Gu Jinxiang To: CC: , Gu JinXiang Subject: [PATCH v2] btrfs: Fix bug for misused dev_t when lookup in dev state hash table. Date: Thu, 19 Oct 2017 09:49:27 +0800 Message-ID: <1508377767-61647-1-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: Gu JinXiang Fix bug of commit 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index"). In this modify, use bio_dev(bio) to find dev state in function __btrfsic_submit_bio. But when dev_state added to hashtable, it is using dev_t of block_device. bio_dev(bio) returns a dev_t of part0 which is different from dev_t in block_device(bd_dev). bd_dev in block_device represents the exact partition. block_device.bd_dev = bio->bi_partno (same as block_device.bd_partno) + bio_dev(bio). When add a dev_state into hashtable it is using the exact partition's dev_t. So when lookup it, it should also use the exact partition's dev_t. Reproduce of this bug: Use MOUNT_OPTIONS="-o check_int" when run btrfs/001 in xfstest. Then there will be WARNING like below. WARNING: btrfs: attempt to write superblock which references block M @29523968 (sda7 /1111654400/2) which is never written! changelog: v1->v2: Add explanation that bio_dev(bio) is different with block_device(bd_dev). Signed-off-by: Gu JinXiang --- fs/btrfs/check-integrity.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c index fb07e3c22b9a..02f9eb83173f 100644 --- a/fs/btrfs/check-integrity.c +++ b/fs/btrfs/check-integrity.c @@ -2803,7 +2803,7 @@ static void __btrfsic_submit_bio(struct bio *bio) mutex_lock(&btrfsic_mutex); /* since btrfsic_submit_bio() is also called before * btrfsic_mount(), this might return NULL */ - dev_state = btrfsic_dev_state_lookup(bio_dev(bio)); + dev_state = btrfsic_dev_state_lookup(bio_dev(bio) + bio->bi_partno); if (NULL != dev_state && (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) { unsigned int i = 0; -- 2.13.5