Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-11-01 Thread Ryan Harper
* Markus Armbruster [2010-10-29 09:08]: > Ryan Harper writes: > > > Block hot unplug is racy since the guest is required to acknowlege the ACPI > > unplug event; this may not happen synchronously with the device removal > > command > > > > This series aims to close a gap where by mgmt applicati

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-30 Thread Christoph Hellwig
On Fri, Oct 29, 2010 at 06:08:03PM +0200, Kevin Wolf wrote: > > I think we've got a bit of a problem. > > > > We have: > > > > 1) bdrv_flush() - sends an fdatasync > > > > 2) bdrv_aio_flush() - sends an fdatasync using the thread pool > > > > 3) qemu_aio_flush() - waits for all pending aio requ

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Kevin Wolf
Am 29.10.2010 17:28, schrieb Anthony Liguori: > On 10/29/2010 09:57 AM, Kevin Wolf wrote: >> Am 29.10.2010 16:40, schrieb Anthony Liguori: >> >>> On 10/29/2010 09:29 AM, Kevin Wolf wrote: >>> Am 29.10.2010 16:15, schrieb Anthony Liguori: > I don't think it's a bad id

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Markus Armbruster
Anthony Liguori writes: > On 10/29/2010 09:01 AM, Markus Armbruster wrote: >> Ryan Harper writes: >> >> >>> Block hot unplug is racy since the guest is required to acknowlege the ACPI >>> unplug event; this may not happen synchronously with the device removal >>> command >>> >>> This series

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Anthony Liguori
On 10/29/2010 09:57 AM, Kevin Wolf wrote: Am 29.10.2010 16:40, schrieb Anthony Liguori: On 10/29/2010 09:29 AM, Kevin Wolf wrote: Am 29.10.2010 16:15, schrieb Anthony Liguori: I don't think it's a bad idea to do that but to the extent that the block API is designed after posi

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Kevin Wolf
Am 29.10.2010 16:40, schrieb Anthony Liguori: > On 10/29/2010 09:29 AM, Kevin Wolf wrote: >> Am 29.10.2010 16:15, schrieb Anthony Liguori: >>> I don't think it's a bad idea to do that but to the extent that the >>> block API is designed after posix file I/O, close does not usually imply >>> flush.

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Anthony Liguori
On 10/29/2010 09:29 AM, Kevin Wolf wrote: Am 29.10.2010 16:15, schrieb Anthony Liguori: On 10/29/2010 09:01 AM, Markus Armbruster wrote: Ryan Harper writes: diff --git a/block.c b/block.c index a19374d..be47655 100644 --- a/block.c +++ b/block.c @@ -1328,6 +1328,13 @@ void

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Kevin Wolf
Am 29.10.2010 16:15, schrieb Anthony Liguori: > On 10/29/2010 09:01 AM, Markus Armbruster wrote: >> Ryan Harper writes: >>> diff --git a/block.c b/block.c >>> index a19374d..be47655 100644 >>> --- a/block.c >>> +++ b/block.c >>> @@ -1328,6 +1328,13 @@ void bdrv_set_removable(BlockDriverState *bs,

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Anthony Liguori
On 10/29/2010 09:01 AM, Markus Armbruster wrote: Ryan Harper writes: Block hot unplug is racy since the guest is required to acknowlege the ACPI unplug event; this may not happen synchronously with the device removal command This series aims to close a gap where by mgmt applications that

Re: [Qemu-devel] [PATCH 2/3] v2 Fix Block Hotplug race with drive_unplug()

2010-10-29 Thread Markus Armbruster
Ryan Harper writes: > Block hot unplug is racy since the guest is required to acknowlege the ACPI > unplug event; this may not happen synchronously with the device removal > command > > This series aims to close a gap where by mgmt applications that assume the > block resource has been removed w