Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-28 Thread Denis Plotnikov
On 27.02.2020 16:48, Eric Blake wrote: On 2/27/20 1:29 AM, Denis Plotnikov wrote: The patch adds some preparation parts for incompatible compression type feature to Qcow2 that indicates which allow to use different compression to qcow2, allowing the use of different methods for image clus

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Eric Blake
On 2/27/20 8:30 AM, Vladimir Sementsov-Ogievskiy wrote: But what is the benefit? We have already documented padding in the spec, and discussed it so much time... What is the problem with padding? And why to add 8 bytes for every new feature which needs only one byte? Okay, so requiring an 8-

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Vladimir Sementsov-Ogievskiy
27.02.2020 17:13, Eric Blake wrote: On 2/27/20 7:59 AM, Vladimir Sementsov-Ogievskiy wrote: Hmm - I think it may be worth a tweak to qcow2.txt to call out: 104: compression_type 105 - 111: padding, must be 0 or else call out: 104-111: compression type and just blindly use all 8 bytes for th

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Eric Blake
On 2/27/20 7:59 AM, Vladimir Sementsov-Ogievskiy wrote: Hmm - I think it may be worth a tweak to qcow2.txt to call out: 104: compression_type 105 - 111: padding, must be 0 or else call out: 104-111: compression type and just blindly use all 8 bytes for the value even though really only 1 or

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Vladimir Sementsov-Ogievskiy
27.02.2020 16:48, Eric Blake wrote: On 2/27/20 1:29 AM, Denis Plotnikov wrote: The patch adds some preparation parts for incompatible compression type feature to Qcow2 that indicates which allow to use different compression to qcow2, allowing the use of different methods for image clusters (

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Eric Blake
On 2/27/20 1:29 AM, Denis Plotnikov wrote: The patch adds some preparation parts for incompatible compression type feature to Qcow2 that indicates which allow to use different compression to qcow2, allowing the use of different methods for image clusters (de)compressing. It is implied that t

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Eric Blake
On 2/27/20 2:21 AM, Vladimir Sementsov-Ogievskiy wrote: 27.02.2020 10:29, Denis Plotnikov wrote: The patch adds some preparation parts for incompatible compression type feature to Qcow2 that indicates which allow to use different compression methods for image clusters (de)compressing. It is imp

Re: [PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-27 Thread Vladimir Sementsov-Ogievskiy
27.02.2020 10:29, Denis Plotnikov wrote: The patch adds some preparation parts for incompatible compression type feature to Qcow2 that indicates which allow to use different compression methods for image clusters (de)compressing. It is implied that the compression type is set on the image creati

[PATCH v1 1/8] qcow2: introduce compression type feature

2020-02-26 Thread Denis Plotnikov
The patch adds some preparation parts for incompatible compression type feature to Qcow2 that indicates which allow to use different compression methods for image clusters (de)compressing. It is implied that the compression type is set on the image creation and can be changed only later by image c