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Date: Fri, 15 Oct 2021 08:57:59 -0700
From: Kees Cook <keescook@chromium.org>
To: Christoph Hellwig <hch@lst.de>
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Cc: Dave Kleikamp <shaggy@kernel.org>, jfs-discussion@lists.sourceforge.net,
	Mike Snitzer <snitzer@redhat.com>, linux-nvme@lists.infradead.org,
	Konstantin Komarov <almaz.alexandrovich@paragon-software.com>,
	Song Liu <song@kernel.org>, dm-devel@redhat.com,
	target-devel@vger.kernel.org, reiserfs-devel@vger.kernel.org,
	drbd-dev@lists.linbit.com, linux-nilfs@vger.kernel.org,
	linux-scsi@vger.kernel.org, OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
	linux-ext4@vger.kernel.org, Chaitanya Kulkarni <kch@nvidia.com>,
	Josef Bacik <josef@toxicpanda.com>, Coly Li <colyli@suse.de>,
	linux-raid@vger.kernel.org, linux-bcache@vger.kernel.org,
	David Sterba <dsterba@suse.com>,
	Ryusuke Konishi <konishi.ryusuke@gmail.com>,
	Anton Altaparmakov <anton@tuxera.com>,
	Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
	linux-nfs@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
	linux-ntfs-dev@lists.sourceforge.net, Jan Kara <jack@suse.com>,
	linux-fsdevel@vger.kernel.org,
	Phillip Lougher <phillip@squashfs.org.uk>, ntfs3@lists.linux.dev,
	linux-btrfs@vger.kernel.org
Subject: Re: [Drbd-dev] [PATCH 08/30] target/iblock: use bdev_nr_bytes
 instead of open coding it
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On Fri, Oct 15, 2021 at 03:26:21PM +0200, Christoph Hellwig wrote:
> Use the proper helper to read the block device size.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

Is this basically an open-coded non-sb version of sb_bdev_nr_blocks()?

Reviewed-by: Kees Cook <keescook@chromium.org>

> ---
>  drivers/target/target_core_iblock.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
> index 31df20abe141f..b1ef041cacd81 100644
> --- a/drivers/target/target_core_iblock.c
> +++ b/drivers/target/target_core_iblock.c
> @@ -232,9 +232,9 @@ static unsigned long long iblock_emulate_read_cap_with_block_size(
>  	struct block_device *bd,
>  	struct request_queue *q)
>  {
> -	unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
> -					bdev_logical_block_size(bd)) - 1);
>  	u32 block_size = bdev_logical_block_size(bd);
> +	unsigned long long blocks_long =
> +		div_u64(bdev_nr_bytes(bd), block_size) - 1;
>  
>  	if (block_size == dev->dev_attrib.block_size)
>  		return blocks_long;
> -- 
> 2.30.2
> 

-- 
Kees Cook