From: Christoph Hellwig <hch@lst.de>
To: Markus Armbruster <armbru@redhat.com>
Cc: kwolf@redhat.com, kraxel@redhat.com,
Christoph Hellwig <hch@lst.de>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Re: [PATCH 08/12] block: Catch attempt to attach multiple devices to a blockdev
Date: Sun, 27 Jun 2010 11:36:09 +0200 [thread overview]
Message-ID: <20100627093609.GA12016@lst.de> (raw)
In-Reply-To: <m3eiftsvk4.fsf@blackfin.pond.sub.org>
On Sat, Jun 26, 2010 at 04:44:11PM +0200, Markus Armbruster wrote:
> Valid question. I'd answer yes. It's an easy error to make, and likely
> to end in massive file system corruption in the guest.
I suspect a modern distro in the guest will detect it as a multi-path setup.
> > Can anyone explain what the hell usb storage is actually trying to do
> > with the two drives?
>
> It's actually a SCSI controller with a single drive on its single bus.
>
> -device usb-storage,drive=foo creates *two* devices: usb-storage itself,
> which serves as SCSI controller, and scsi-disk for the drive.
> usb-storage copies its drive property to scsi-disk.
>
> I don't like this. Each -device should create just one device.
Indeed. I'd also prefer to get rid of this. Anthony, how hard are the
rules on backwards compatiblity for things like this?
Note that currently the usb storage emulation is extremly broken anyway,
just writing to it produces I/O errors after a short while. This means
it can't be used very much at all.
next prev parent reply other threads:[~2010-06-27 9:36 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-25 16:53 [Qemu-devel] [PATCH 00/12] More block-related fixes and cleanups Markus Armbruster
2010-06-25 16:53 ` [Qemu-devel] [PATCH 01/12] scsi: scsi_bus_legacy_handle_cmdline() can fail, fix callers Markus Armbruster
2010-06-25 19:39 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 02/12] ide: Make it explicit that ide_create_drive() can't fail Markus Armbruster
2010-06-25 19:40 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 03/12] blockdev: Remove drive_get_serial() Markus Armbruster
2010-06-25 19:41 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 04/12] blockdev: New drive_of_blockdev() Markus Armbruster
2010-06-25 19:42 ` [Qemu-devel] " Christoph Hellwig
2010-06-26 5:32 ` Markus Armbruster
2010-06-26 9:46 ` Christoph Hellwig
2010-06-26 14:46 ` Markus Armbruster
2010-06-27 9:36 ` Christoph Hellwig
2010-06-28 9:58 ` Paolo Bonzini
2010-06-29 8:57 ` Markus Armbruster
2010-06-25 16:53 ` [Qemu-devel] [PATCH 05/12] blockdev: Clean up automatic drive deletion Markus Armbruster
2010-06-26 9:48 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 06/12] qdev: Decouple qdev_prop_drive from DriveInfo Markus Armbruster
2010-06-26 10:09 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 07/12] blockdev: drive_get_by_id() is no longer used, remove Markus Armbruster
2010-06-26 10:09 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 08/12] block: Catch attempt to attach multiple devices to a blockdev Markus Armbruster
2010-06-26 10:11 ` [Qemu-devel] " Christoph Hellwig
2010-06-26 14:44 ` Markus Armbruster
2010-06-27 9:36 ` Christoph Hellwig [this message]
2010-06-28 8:24 ` Kevin Wolf
2010-06-28 10:16 ` Christoph Hellwig
2010-06-28 10:26 ` Kevin Wolf
2010-06-30 11:52 ` Markus Armbruster
2010-06-30 12:13 ` Kevin Wolf
2010-06-29 8:06 ` Gerd Hoffmann
2010-06-30 11:33 ` Markus Armbruster
2010-06-29 13:32 ` Kevin Wolf
2010-06-29 14:29 ` Markus Armbruster
2010-06-29 14:58 ` [Qemu-devel] [PATCH v2 " Markus Armbruster
2010-06-25 16:53 ` [Qemu-devel] [PATCH 09/12] savevm: Survive hot-unplug of snapshot device Markus Armbruster
2010-06-26 10:12 ` [Qemu-devel] " Christoph Hellwig
2010-06-30 11:28 ` Markus Armbruster
2010-06-30 13:37 ` Kevin Wolf
2010-06-30 16:34 ` Markus Armbruster
2010-06-25 16:53 ` [Qemu-devel] [PATCH 10/12] block: Fix virtual media change for if=none Markus Armbruster
2010-06-26 10:14 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 11/12] ide: Make PIIX and ISA IDE init functions return the qdev Markus Armbruster
2010-06-26 10:14 ` [Qemu-devel] " Christoph Hellwig
2010-06-25 16:53 ` [Qemu-devel] [PATCH 12/12] pc: Fix CMOS info for drives defined with -device Markus Armbruster
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100627093609.GA12016@lst.de \
--to=hch@lst.de \
--cc=armbru@redhat.com \
--cc=kraxel@redhat.com \
--cc=kwolf@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).