From d28e649a5c58b779b303c252c66ee84a0f2c3b32 Mon Sep 17 00:00:00 2001 From: Gu JinXiang Date: Thu, 19 Oct 2017 09:49:27 +0800 Subject: [PATCH] btrfs: Fix bug for misused dev_t when lookup in dev state hash table. Fix bug of commit 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index"). bio_dev(bio) is used to find the dev state in function __btrfsic_submit_bio. But when dev_state is added to the 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 adding a dev_state into hashtable, we use the exact partition dev_t. So when looking it up, it should also use the exact partition dev_t. Reproducer of this bug: Use MOUNT_OPTIONS="-o check_int" and run btrfs/001 in fstests. 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! Signed-off-by: Gu JinXiang Reviewed-by: David Sterba Signed-off-by: David Sterba --- 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 1fee5fe..7d51b5a 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; -- 2.7.4