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Date: Wed, 23 Apr 2003 15:35:00 -0700
From: Andrew Morton <akpm@digeo.com>
To: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: alan@lxorguk.ukuu.org.uk, andre@linux-ide.org, axboe@suse.de,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] 2.5.67-ac2 direct-IO for IDE taskfile ioctl (0/4)
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Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> wrote:
>
> 
> Hey,
> 
> Another bunch of patches:
> 
> (1) Enhance bio_(un)map_user() and add blk_rq_bio_prep().
> (2) Pass bdev to IDE ioctl handlers.
> (3) Add support for rq->bio based taskfile.
> (4) Use direct-IO in ide_taskfile_ioctl() and in ide_cmd_ioctl().

Dumb question: what does all this code actually do?

It appears to be implementing an IDE-specific ioctl() which performs bulk
IO direct to/from userspace.  But that seems to be equivalent to O_DIRECT
access to /dev/hda.

What is special about the IDE ioctl approach?

Thanks.