From: Richard Weinberger <richard@nod.at>
To: Christoph Hellwig <hch@lst.de>
Cc: axboe@kernel.dk, linux-block@vger.kernel.org,
linux-um@lists.infradead.org, anton.ivanov@cambridgegreys.com
Subject: Re: [PATCH, RFC] ubd: remove use of blk_rq_map_sg
Date: Mon, 15 Oct 2018 21:17:46 +0200 [thread overview]
Message-ID: <20263939.GgfHUqOn1T@blindfold> (raw)
In-Reply-To: <20181015084541.GA27159@lst.de>
Am Montag, 15. Oktober 2018, 10:45:41 CEST schrieb Christoph Hellwig:
> On Mon, Oct 15, 2018 at 10:40:06AM +0200, Richard Weinberger wrote:
> > hm, this breaks UML.
> > Every filesystem fails to mount.
> >
> > I did some very rough tests, it seems that the driver fails to read
> > data correctly as soon the upper layer tries to get more than 4096 bytes
> > at once out of the block device.
> >
> > IOW:
> > dd if=/dev/ubda bs=4096 count=1 skip=0 2>/dev/null| md5sum -
> > is good.
> > As soon I set bs to something greater it returns garbage.
> >
> > Later this day I might have some cycles left to debug further.
>
> It probably needs this on top:
Sadly not. I'm checking now what exactly is broken.
BTW: Why are you using for_each_bio() with bio_for_each_segment()?
I thought we have rq_for_each_segment() for that.
Thanks,
//richard
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next prev parent reply other threads:[~2018-10-15 19:18 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-15 6:56 [PATCH, RFC] ubd: remove use of blk_rq_map_sg Christoph Hellwig
2018-10-15 8:40 ` Richard Weinberger
2018-10-15 8:45 ` Christoph Hellwig
2018-10-15 19:17 ` Richard Weinberger [this message]
2018-10-15 20:42 ` Richard Weinberger
2018-10-15 20:55 ` Christoph Hellwig
2018-10-15 21:46 ` Richard Weinberger
2018-10-15 22:04 ` Jens Axboe
2018-10-15 22:44 ` Richard Weinberger
2018-10-16 2:19 ` Jens Axboe
2018-10-16 8:38 ` Richard Weinberger
2018-10-16 14:26 ` Jens Axboe
2018-10-17 6:21 ` Christoph Hellwig
2018-10-18 21:04 ` Richard Weinberger
2018-10-15 8:46 ` Anton Ivanov
2018-10-16 22:43 ` Richard Weinberger
2018-10-17 6:14 ` Christoph Hellwig
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