Re: [Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-09-11 Thread Alberto Garcia
On Thu 09 Aug 2018 11:35:01 PM CEST, Max Reitz wrote: > @@ -295,11 +296,13 @@ static int qcow_open(BlockDriverState *bs, QDict > *options, int flags, > goto fail; > } > ret = bdrv_pread(bs->file, header.backing_file_offset, > - bs->backing_file, len

Re: [Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-09-10 Thread Alberto Garcia
On Fri 07 Sep 2018 02:42:53 PM CEST, Max Reitz wrote: > The whole purpose of bs->auto_backing_file is so you can compare it > with bs->backing->bs->filename, see when it differs, and then you know > that the user has changed the backing file from what it would be based > on the image header alone (

Re: [Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-09-07 Thread Max Reitz
On 2018-09-07 14:28, Alberto Garcia wrote: > On Fri 07 Sep 2018 01:32:58 PM CEST, Max Reitz wrote: >> On 2018-09-05 16:22, Alberto Garcia wrote: >>> On Thu 09 Aug 2018 11:35:01 PM CEST, Max Reitz wrote: If the backing file is overridden, this most probably does change the guest-visible da

Re: [Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-09-07 Thread Alberto Garcia
On Fri 07 Sep 2018 01:32:58 PM CEST, Max Reitz wrote: > On 2018-09-05 16:22, Alberto Garcia wrote: >> On Thu 09 Aug 2018 11:35:01 PM CEST, Max Reitz wrote: >>> If the backing file is overridden, this most probably does change the >>> guest-visible data of a BDS. Therefore, we will need to consider

Re: [Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-09-07 Thread Max Reitz
On 2018-09-05 16:22, Alberto Garcia wrote: > On Thu 09 Aug 2018 11:35:01 PM CEST, Max Reitz wrote: >> If the backing file is overridden, this most probably does change the >> guest-visible data of a BDS. Therefore, we will need to consider this >> in bdrv_refresh_filename(). >> >> To see whether i

Re: [Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-09-05 Thread Alberto Garcia
On Thu 09 Aug 2018 11:35:01 PM CEST, Max Reitz wrote: > If the backing file is overridden, this most probably does change the > guest-visible data of a BDS. Therefore, we will need to consider this > in bdrv_refresh_filename(). > > To see whether it has been overridden, we might want to compare >

[Qemu-devel] [PATCH for-3.1 v10 04/31] block: Add BDS.auto_backing_file

2018-08-09 Thread Max Reitz
If the backing file is overridden, this most probably does change the guest-visible data of a BDS. Therefore, we will need to consider this in bdrv_refresh_filename(). To see whether it has been overridden, we might want to compare bs->backing_file and bs->backing->bs->filename. However, bs->bac