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Date:   Wed, 13 Dec 2023 17:11:21 -0800
From:   Keith Busch <kbusch@kernel.org>
To:     Kanchan Joshi <joshi.k@samsung.com>
Cc:     Jens Axboe <axboe@kernel.dk>, Jonathan Corbet <corbet@lwn.net>,
        Alasdair Kergon <agk@redhat.com>,
        Mike Snitzer <snitzer@kernel.org>,
        Mikulas Patocka <mpatocka@redhat.com>,
        dm-devel@lists.linux.dev, Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        Chaitanya Kulkarni <kch@nvidia.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        martin.petersen@oracle.com, linux-scsi@vger.kernel.org,
        nitheshshetty@gmail.com, anuj1072538@gmail.com,
        gost.dev@samsung.com, mcgrof@kernel.org,
        Nitesh Shetty <nj.shetty@samsung.com>,
        Anuj Gupta <anuj20.g@samsung.com>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v18 02/12] Add infrastructure for copy offload in block
 and request layer.
Message-ID: <ZXpWOaxCRoF7dFis@kbusch-mbp>
References: <20231206100253.13100-1-joshi.k@samsung.com>
 <CGME20231206101050epcas5p2c8233030bbf74cef0166c7dfc0f41be7@epcas5p2.samsung.com>
 <20231206100253.13100-3-joshi.k@samsung.com>
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On Wed, Dec 06, 2023 at 03:32:34PM +0530, Kanchan Joshi wrote:
>  static inline bool bio_has_data(struct bio *bio)
>  {
> -	if (bio &&
> -	    bio->bi_iter.bi_size &&
> -	    bio_op(bio) != REQ_OP_DISCARD &&
> -	    bio_op(bio) != REQ_OP_SECURE_ERASE &&
> -	    bio_op(bio) != REQ_OP_WRITE_ZEROES)
> +	if (bio && (bio_op(bio) == REQ_OP_READ || bio_op(bio) == REQ_OP_WRITE))
>  		return true;

There are other ops besides READ and WRITE that have data, but this is
might be fine by the fact that other ops with data currently don't call
this function.

> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index 7c2316c91cbd..bd821eaa7a02 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -393,6 +393,10 @@ enum req_op {
>  	/* reset all the zone present on the device */
>  	REQ_OP_ZONE_RESET_ALL	= (__force blk_opf_t)17,
>  
> +	/* copy offload dst and src operation */
> +	REQ_OP_COPY_SRC		= (__force blk_opf_t)19,

Should this be an even numbered OP? The odd ones are for data
WRITEs.

> +	REQ_OP_COPY_DST		= (__force blk_opf_t)21,