linux-kernel - Re: [PATCH 42/41] dm: convey that all flushes are processed as empty

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]

Message-ID: <20100908000001.GA21552@lst.de>
Date:	Wed, 8 Sep 2010 02:00:01 +0200
From:	Christoph Hellwig <hch@....de>
To:	Mike Snitzer <snitzer@...hat.com>
Cc:	Tejun Heo <tj@...nel.org>, jack@...e.cz, mst@...hat.com,
	linux-ide@...r.kernel.org,
	device-mapper development <dm-devel@...hat.com>,
	James.Bottomley@...e.de, konishi.ryusuke@....ntt.co.jp, hch@....de,
	k-ueda@...jp.nec.com, vst@...b.net, linux-scsi@...r.kernel.org,
	rusty@...tcorp.com.au, linux-raid@...r.kernel.org,
	mpatocka@...hat.com, swhiteho@...hat.com, chris.mason@...cle.com,
	tytso@....edu, jaxboe@...ionio.com, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, rwheeler@...hat.com,
	Milan Broz <mbroz@...hat.com>
Subject: Re: [PATCH 42/41] dm: convey that all flushes are processed as empty

On Tue, Sep 07, 2010 at 07:49:18PM -0400, Mike Snitzer wrote:
>  		if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
> +			/* done with normal IO or empty flush */
>  			trace_block_bio_complete(md->queue, bio);
>  			bio_endio(bio, io_error);
>  		} else {

To clarify this further I'd reorder the checks:

		if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) {
			/*
			 * Preflush done, ...
			 */
		} else {
		}

> @@ -1302,20 +1302,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
>  	ci.sector = bio->bi_sector;
>  	ci.idx = bio->bi_idx;
>  
> +	start_io_acct(ci.io);
>  	if (!is_flush) {

no need for the is_flush anymore now that it's only used once.  Again,
I think avoiding negatives without a reason in if statement usually
makes the code a bit more clear.

--
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/