Re: [PATCH] mkfs.btrfs: round all device sizes to sectorsize

[Anand Jain <Anand.Jain@oracle.com>]

On 07/25/2014 12:27 PM, Eric Sandeen wrote:
> make_btrfs() rounds down the first device size to a multiple of sectorsize:
>
> 	num_bytes = (num_bytes / sectorsize) * sectorsize;
>
> but subsequent device adds don't.
>
> This seems a bit odd & inconsistent, and it makes xfstest btrfs/011
> _notrun(), because it explicitly checks that devices are the same size.
>
> I don't know that there is anything inherently wrong with having
> a few device bytes extend past the last block, but to be consistent,
> it seems like btrfs_add_to_fsid() should round the size in the same
> way.
>
> And now btrfs/011 runs more consistently; the test devices don't
> have to be sectorsize multiples in order for all mkfs'd device
> sizes to match.

> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
>
> ideally this might go into btrfs_device_size(), but we don't have
> the chosen sector size anywhere near there...
>
> diff --git a/utils.c b/utils.c
> index e130849..4d7ee35 100644
> --- a/utils.c
> +++ b/utils.c
> @@ -554,7 +554,7 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
>   	device->sector_size = sectorsize;
>   	device->fd = fd;
>   	device->writeable = 1;
> -	device->total_bytes = block_count;
> +	device->total_bytes = (block_count / sectorsize) * sectorsize;
>   	device->bytes_used = 0;
>   	device->total_ios = 0;
>   	device->dev_root = root->fs_info->dev_root;


its better to do this at the function btrfs_prepare_device() itself,
so that it would include first and the rest added.
or
we need to apply this on the block_count instead, as we do add
that to the total_bytes.

Thanks, Anand

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