linux-kernel - Re: [PATCH 4/6] virtio-blk: implement init_flush

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 7 Sep 2014 20:52:59 +0200
From:	Christoph Hellwig <hch@....de>
To:	Ming Lei <ming.lei@...onical.com>
Cc:	Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org,
	linux-scsi@...r.kernel.org
Subject: Re: [PATCH 4/6] virtio-blk: implement init_flush_rq

A couple comments not directly related to this patch, it's just
a convenient vehicle for my rants :)

> @@ -556,6 +555,19 @@ static int virtblk_init_request(void *data, struct request *rq,
>  	struct virtio_blk *vblk = data;
>  	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
>  
> +	vbr->req = rq;

I really hate how we need these backpointers in most drivers.  Given
that struct request and the driver privata data are allocated together
we should be able to do this with simple pointer arithmetics.

> +	sg_init_table(vbr->sg, vblk->sg_elems);

Jens, what do you think about moving of the SG list handling to the
core block layer?  I'd really like to have the S/G list in struct request,
and if we do that we could also take the scsi-mq code that allows small
S/G lists preallocated in blk-mq and allocating larger ones at runtime
there, avoiding the need to duplicate that code and the whole mempool
magic it requires in drivers that want to make use of it.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/