Re: [PATCH 30/45] block: remove the nr_sects field in struct hd_struct

[Coly Li <colyli@xxxxxxx>]

On 11/24/20 9:27 PM, Christoph Hellwig wrote:
> Now that the hd_struct always has a block device attached to it, there is
> no need for having two size field that just get out of sync.
> 
> Additional the field in hd_struct did not use proper serializiation,
> possibly allowing for torn writes.  By only using the block_device field
> this problem also gets fixed.
> 
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

For the bcache part, Acked-by: Coly Li <colyli@xxxxxxx>

Thanks.

Coly Li

> ---
>  block/bio.c                        |  4 +-
>  block/blk-core.c                   |  2 +-
>  block/blk.h                        | 53 ----------------------
>  block/genhd.c                      | 55 +++++++++++-----------
>  block/partitions/core.c            | 17 ++++---
>  drivers/block/loop.c               |  1 -
>  drivers/block/nbd.c                |  2 +-
>  drivers/block/xen-blkback/common.h |  4 +-
>  drivers/md/bcache/super.c          |  2 +-
>  drivers/s390/block/dasd_ioctl.c    |  4 +-
>  drivers/target/target_core_pscsi.c |  7 +--
>  fs/block_dev.c                     | 73 +-----------------------------
>  fs/f2fs/super.c                    |  2 +-
>  fs/pstore/blk.c                    |  2 +-
>  include/linux/genhd.h              | 29 +++---------
>  kernel/trace/blktrace.c            |  2 +-
>  16 files changed, 60 insertions(+), 199 deletions(-)
> 
[snipped]

> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index c55d3c58a7ef55..04fa40868fbe10 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -1408,7 +1408,7 @@ static int cached_dev_init(struct cached_dev *dc, 
> unsigned int block_size)
>                       q->limits.raid_partial_stripes_expensive;
>  
>       ret = bcache_device_init(&dc->disk, block_size,
> -                      dc->bdev->bd_part->nr_sects - dc->sb.data_offset,
> +                      bdev_nr_sectors(dc->bdev) - dc->sb.data_offset,
>                        dc->bdev, &bcache_cached_ops);
>       if (ret)
>               return ret;
[snipped]