From: Alex Bligh <alex@alex.org.uk>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>,
Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>,
George Dunlap <George.Dunlap@eu.citrix.com>,
Ian Jackson <Ian.Jackson@eu.citrix.com>,
qemu-devel@nongnu.org, xen-devel <xen-devel@lists.xen.org>,
Anthony Liguori <anthony@codemonkey.ws>,
Alex Bligh <alex@alex.org.uk>
Subject: Re: [Qemu-devel] [Xen-devel] [PATCHv3] QEMU(upstream): Disable xen's use of O_DIRECT by default as it results in crashes.
Date: Wed, 20 Mar 2013 08:33:02 +0000 [thread overview]
Message-ID: <D78EB4113B16FAEE83B97084@nimrod.local> (raw)
In-Reply-To: <alpine.DEB.2.02.1303191454170.4716@kaball.uk.xensource.com>
Stefano,
--On 19 March 2013 15:13:29 +0000 Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> Therefore I think that the current change is not safe, but it is pretty
> easy to make it safe.
> You just need to move the call to blk_open from blk_init to blk_connect.
> Actually you can move most of blk_init to blk_connect, you just need to
> keep the 4 xenstore_write_be_int at the end of the function.
The final of these 4 writes in blk_init is:
xenstore_write_be_int(&blkdev->xendev, "sectors",
blkdev->file_size / blkdev->file_blk);
and blkdev->filesize comes from bdrv_getlength(blkdev->bs), and that
requires (I think) bdrv_open to have been called. Can these
4 writes move safely to blk_connect? Or can we write the sectors
count as (say) 0 here and fix it later in blk_connect? The remainder
look ok.
--
Alex Bligh
next prev parent reply other threads:[~2013-03-20 8:48 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-18 12:18 [Qemu-devel] [PATCHv3] QEMU(upstream): Disable xen's use of O_DIRECT by default as it results in crashes Alex Bligh
2013-03-18 13:03 ` Stefan Hajnoczi
2013-03-18 13:19 ` Alex Bligh
2013-03-18 13:32 ` Paolo Bonzini
2013-03-18 13:49 ` Alex Bligh
2013-03-18 14:05 ` Paolo Bonzini
2013-03-18 14:30 ` Alex Bligh
2013-03-18 14:49 ` Paolo Bonzini
2013-03-18 15:40 ` Alex Bligh
2013-03-18 16:19 ` Paolo Bonzini
2013-03-18 16:53 ` Alex Bligh
2013-03-18 17:38 ` George Dunlap
2013-03-18 17:47 ` Alex Bligh
2013-03-18 18:00 ` Paolo Bonzini
2013-03-19 10:06 ` [Qemu-devel] [Xen-devel] " George Dunlap
2013-03-19 10:43 ` Paolo Bonzini
2013-03-19 10:51 ` George Dunlap
2013-03-19 11:14 ` Paolo Bonzini
2013-03-19 11:21 ` George Dunlap
2013-03-19 15:12 ` George Dunlap
2013-03-19 15:29 ` George Dunlap
2013-03-19 19:15 ` Alex Bligh
2013-03-20 10:24 ` Stefano Stabellini
2013-03-20 10:37 ` George Dunlap
2013-03-20 11:08 ` Paolo Bonzini
2013-03-20 11:20 ` Alex Bligh
2013-03-20 11:57 ` David Scott
2013-03-19 11:44 ` Alex Bligh
2013-03-19 11:49 ` Paolo Bonzini
2013-03-19 15:13 ` Stefano Stabellini
2013-03-19 16:53 ` Paolo Bonzini
2013-03-19 17:03 ` Stefano Stabellini
2013-03-20 8:33 ` Alex Bligh [this message]
2013-03-20 9:26 ` Paolo Bonzini
2013-03-29 17:19 ` Stefano Stabellini
2013-03-31 19:53 ` Alex Bligh
2013-04-01 15:32 ` [Qemu-devel] [PATCH] [RFC] Xen PV backend: Move call to bdrv_new from blk_init to blk_connect Alex Bligh
2013-04-01 15:44 ` Stefano Stabellini
2013-04-01 20:56 ` Alex Bligh
2013-04-02 11:08 ` Stefano Stabellini
2013-04-05 10:31 ` [Qemu-devel] [PATCHv2 1/2] " Alex Bligh
2013-04-05 10:31 ` [Qemu-devel] [PATCHv2 2/2] Xen PV backend: Disable use of O_DIRECT by default as it results in crashes Alex Bligh
2013-04-05 14:22 ` [Qemu-devel] [PATCHv2 1/2] Xen PV backend: Move call to bdrv_new from blk_init to blk_connect Stefano Stabellini
2013-04-05 15:42 ` [Qemu-devel] [PATCHv3 " Alex Bligh
2013-04-05 15:42 ` [Qemu-devel] [PATCHv3 2/2] Xen PV backend: Disable use of O_DIRECT by default as it results in crashes Alex Bligh
2013-04-05 15:43 ` [Qemu-devel] [PATCHv2 1/2] Xen PV backend: Move call to bdrv_new from blk_init to blk_connect Alex Bligh
2013-04-05 10:32 ` [Qemu-devel] [PATCHv2 1/2] Xen PV backend (for qemu-upstream-4.2-testing): " Alex Bligh
2013-04-05 10:32 ` [Qemu-devel] [PATCHv2 2/2] Xen PV backend (for qemu-upstream-4.2-testing): Disable use of O_DIRECT by default as it results in crashes Alex Bligh
2013-04-05 10:34 ` [Qemu-devel] [PATCH] [RFC] Xen PV backend: Move call to bdrv_new from blk_init to blk_connect Alex Bligh
2013-04-01 16:35 ` [Qemu-devel] [Xen-devel] [PATCHv3] QEMU(upstream): Disable xen's use of O_DIRECT by default as it results in crashes Alex Bligh
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