Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread John Snow
On 04/13/2017 11:02 AM, Jeff Cody wrote: > On Thu, Apr 13, 2017 at 03:39:59PM +0100, Stefan Hajnoczi wrote: >> On Thu, Apr 13, 2017 at 01:45:55PM +0800, Paolo Bonzini wrote: >>> >>> >>> On 13/04/2017 09:11, Jeff Cody wrote: > It didn't make it into 2.9-rc4 because of limited time. :( > >>

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Jeff Cody
On Thu, Apr 13, 2017 at 03:39:59PM +0100, Stefan Hajnoczi wrote: > On Thu, Apr 13, 2017 at 01:45:55PM +0800, Paolo Bonzini wrote: > > > > > > On 13/04/2017 09:11, Jeff Cody wrote: > > >> It didn't make it into 2.9-rc4 because of limited time. :( > > >> > > >> Looks like there is no -rc5, we'll ha

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Peter Maydell
On 13 April 2017 at 15:33, Eric Blake wrote: > On 04/13/2017 04:48 AM, Peter Maydell wrote: >> Well, we *hope* there is no -rc5, but if the bug is genuinely >> a "we can't release like this" bug we will obviously have to >> do another rc. Basically you all as the block maintainers should >> make t

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Jeff Cody
On Thu, Apr 13, 2017 at 09:45:49AM -0500, Eric Blake wrote: > On 04/13/2017 09:39 AM, Stefan Hajnoczi wrote: > > On Thu, Apr 13, 2017 at 01:45:55PM +0800, Paolo Bonzini wrote: > >> > >> > >> On 13/04/2017 09:11, Jeff Cody wrote: > It didn't make it into 2.9-rc4 because of limited time. :( > >>

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Eric Blake
On 04/13/2017 09:39 AM, Stefan Hajnoczi wrote: > On Thu, Apr 13, 2017 at 01:45:55PM +0800, Paolo Bonzini wrote: >> >> >> On 13/04/2017 09:11, Jeff Cody wrote: It didn't make it into 2.9-rc4 because of limited time. :( Looks like there is no -rc5, we'll have to document this as a know

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Stefan Hajnoczi
On Thu, Apr 13, 2017 at 01:45:55PM +0800, Paolo Bonzini wrote: > > > On 13/04/2017 09:11, Jeff Cody wrote: > >> It didn't make it into 2.9-rc4 because of limited time. :( > >> > >> Looks like there is no -rc5, we'll have to document this as a known issue. > >> Users should "block-job-complete/can

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Eric Blake
On 04/13/2017 04:48 AM, Peter Maydell wrote: > On 13 April 2017 at 00:54, Fam Zheng wrote: >> John and I confirmed that this can be fixed by this pending patch: >> >> [PATCH for-2.9 4/5] block: Drain BH in bdrv_drained_begin >> >> https://lists.gnu.org/archive/html/qemu-devel/2017-04/msg01018.html

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-13 Thread Peter Maydell
On 13 April 2017 at 00:54, Fam Zheng wrote: > John and I confirmed that this can be fixed by this pending patch: > > [PATCH for-2.9 4/5] block: Drain BH in bdrv_drained_begin > > https://lists.gnu.org/archive/html/qemu-devel/2017-04/msg01018.html > > It didn't make it into 2.9-rc4 because of limit

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread Paolo Bonzini
On 13/04/2017 09:11, Jeff Cody wrote: >> It didn't make it into 2.9-rc4 because of limited time. :( >> >> Looks like there is no -rc5, we'll have to document this as a known issue. >> Users should "block-job-complete/cancel" as soon as possible to avoid such a >> hang. > > I'd argue for including

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread Jeff Cody
On Wed, Apr 12, 2017 at 09:11:09PM -0400, Jeff Cody wrote: > On Thu, Apr 13, 2017 at 07:54:20AM +0800, Fam Zheng wrote: > > On Wed, 04/12 18:22, Jeff Cody wrote: > > > On Wed, Apr 12, 2017 at 05:38:17PM -0400, John Snow wrote: > > > > > > > > > > > > On 04/12/2017 04:46 PM, Jeff Cody wrote: > > >

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread Jeff Cody
On Thu, Apr 13, 2017 at 07:54:20AM +0800, Fam Zheng wrote: > On Wed, 04/12 18:22, Jeff Cody wrote: > > On Wed, Apr 12, 2017 at 05:38:17PM -0400, John Snow wrote: > > > > > > > > > On 04/12/2017 04:46 PM, Jeff Cody wrote: > > > > > > > > This occurs on v2.9.0-rc4, but not on v2.8.0. > > > > > >

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread Fam Zheng
On Wed, 04/12 18:22, Jeff Cody wrote: > On Wed, Apr 12, 2017 at 05:38:17PM -0400, John Snow wrote: > > > > > > On 04/12/2017 04:46 PM, Jeff Cody wrote: > > > > > > This occurs on v2.9.0-rc4, but not on v2.8.0. > > > > > > When running QEMU with an iothread, and then performing a block-mirror, i

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread Jeff Cody
On Wed, Apr 12, 2017 at 05:38:17PM -0400, John Snow wrote: > > > On 04/12/2017 04:46 PM, Jeff Cody wrote: > > > > This occurs on v2.9.0-rc4, but not on v2.8.0. > > > > When running QEMU with an iothread, and then performing a block-mirror, if > > we do a system-reset after the BLOCK_JOB_READY e

Re: [Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread John Snow
On 04/12/2017 04:46 PM, Jeff Cody wrote: > > This occurs on v2.9.0-rc4, but not on v2.8.0. > > When running QEMU with an iothread, and then performing a block-mirror, if > we do a system-reset after the BLOCK_JOB_READY event has emitted, qemu > becomes deadlocked. > > The block job is not paus

[Qemu-devel] Regression from 2.8: stuck in bdrv_drain()

2017-04-12 Thread Jeff Cody
This occurs on v2.9.0-rc4, but not on v2.8.0. When running QEMU with an iothread, and then performing a block-mirror, if we do a system-reset after the BLOCK_JOB_READY event has emitted, qemu becomes deadlocked. The block job is not paused, nor cancelled, so we are stuck in the while loop in blo