Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-09-03 Thread Kevin Wolf
Am 02.09.2015 um 16:18 hat Stefan Hajnoczi geschrieben: > On Wed, Aug 19, 2015 at 10:54:44AM +0800, Wen Congyang wrote: > > We will copy data in before_write_notifier to do backup. > > It is a nested I/O request, so we cannot do copy-on-read. > > > > Signed-off-by: Wen Congyang > > --- > > block

Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-09-02 Thread Jeff Cody
On Wed, Sep 02, 2015 at 03:18:54PM +0100, Stefan Hajnoczi wrote: > On Wed, Aug 19, 2015 at 10:54:44AM +0800, Wen Congyang wrote: > > We will copy data in before_write_notifier to do backup. > > It is a nested I/O request, so we cannot do copy-on-read. > > > > Signed-off-by: Wen Congyang > > --- >

Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-09-02 Thread Stefan Hajnoczi
On Wed, Aug 19, 2015 at 10:54:44AM +0800, Wen Congyang wrote: > We will copy data in before_write_notifier to do backup. > It is a nested I/O request, so we cannot do copy-on-read. > > Signed-off-by: Wen Congyang > --- > block/backup.c| 19 +-- > block/io.c| 1

Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-08-20 Thread Wen Congyang
On 08/20/2015 01:02 AM, Jeff Cody wrote: > On Wed, Aug 19, 2015 at 01:43:41PM +0800, Wen Congyang wrote: >> On 08/19/2015 01:41 PM, Paolo Bonzini wrote: >>> On 18/08/2015 19:54, Wen Congyang wrote: We will copy data in before_write_notifier to do backup. It is a nested I/O request, so we

Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-08-19 Thread Jeff Cody
On Wed, Aug 19, 2015 at 01:43:41PM +0800, Wen Congyang wrote: > On 08/19/2015 01:41 PM, Paolo Bonzini wrote: > > On 18/08/2015 19:54, Wen Congyang wrote: > >> We will copy data in before_write_notifier to do backup. > >> It is a nested I/O request, so we cannot do copy-on-read. > > > > Can you exp

Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-08-18 Thread Wen Congyang
On 08/19/2015 01:41 PM, Paolo Bonzini wrote: > On 18/08/2015 19:54, Wen Congyang wrote: >> We will copy data in before_write_notifier to do backup. >> It is a nested I/O request, so we cannot do copy-on-read. > > Can you explain why? What is the bug that this is fixing? (gdb) bt #0 0x7fd53a

Re: [Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-08-18 Thread Paolo Bonzini
On 18/08/2015 19:54, Wen Congyang wrote: > We will copy data in before_write_notifier to do backup. > It is a nested I/O request, so we cannot do copy-on-read. Can you explain why? What is the bug that this is fixing? Paolo > Signed-off-by: Wen Congyang

[Qemu-devel] [PATCH] Block: don't do copy-on-read in before_write_notifier

2015-08-18 Thread Wen Congyang
We will copy data in before_write_notifier to do backup. It is a nested I/O request, so we cannot do copy-on-read. Signed-off-by: Wen Congyang --- block/backup.c| 19 +-- block/io.c| 11 ++- include/block/block.h | 3 +++ trace-events | 1 +