Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-05-15 Thread Max Reitz
On 2017-05-13 01:00, John Snow wrote: > > > On 05/12/2017 12:06 PM, Max Reitz wrote: >> On 2017-05-11 16:56, Eric Blake wrote: >>> [revisiting this older patch version, even though the final version in >>> today's pull request changed somewhat from this approach] >>> >>> On 04/12/2017 04:49 AM,

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-05-12 Thread John Snow
On 05/12/2017 12:06 PM, Max Reitz wrote: > On 2017-05-11 16:56, Eric Blake wrote: >> [revisiting this older patch version, even though the final version in >> today's pull request changed somewhat from this approach] >> >> On 04/12/2017 04:49 AM, Kevin Wolf wrote: >>> Am 11.04.2017 um 03:17 hat

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-05-12 Thread Max Reitz
On 2017-05-11 16:56, Eric Blake wrote: > [revisiting this older patch version, even though the final version in > today's pull request changed somewhat from this approach] > > On 04/12/2017 04:49 AM, Kevin Wolf wrote: >> Am 11.04.2017 um 03:17 hat Eric Blake geschrieben: >>> 'qemu-img map'

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-05-11 Thread Eric Blake
On 05/11/2017 09:56 AM, Eric Blake wrote: > > On IRC, John, Kevin, and I were discussing the current situation with > libvirt NBD storage migration. When libvirt creates a file on the > destination (rather than the user pre-creating it), it currently > defaults to 0.10 [v2] images, even if the

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-05-11 Thread Eric Blake
[revisiting this older patch version, even though the final version in today's pull request changed somewhat from this approach] On 04/12/2017 04:49 AM, Kevin Wolf wrote: > Am 11.04.2017 um 03:17 hat Eric Blake geschrieben: >> 'qemu-img map' already coalesces information about unallocated >>

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-04-21 Thread Eric Blake
On 04/12/2017 04:49 AM, Kevin Wolf wrote: >> Furthermore, this matches the behavior of discard_single_l2(), in >> favoring an unallocated cluster over a zero cluster when full >> discard is requested. > > The only use for "full discard" is qcow2_make_empty(). It explicitly > requests that the

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-04-12 Thread Eric Blake
On 04/12/2017 04:49 AM, Kevin Wolf wrote: > Am 11.04.2017 um 03:17 hat Eric Blake geschrieben: >> 'qemu-img map' already coalesces information about unallocated >> clusters (those with status 0) and pure zero clusters (those >> with status BDRV_BLOCK_ZERO and no offset). Furthermore, all >> qcow2

Re: [Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-04-12 Thread Kevin Wolf
Am 11.04.2017 um 03:17 hat Eric Blake geschrieben: > 'qemu-img map' already coalesces information about unallocated > clusters (those with status 0) and pure zero clusters (those > with status BDRV_BLOCK_ZERO and no offset). Furthermore, all > qcow2 images with no backing file already report all

[Qemu-block] [PATCH v9 01/13] qcow2: Unallocate unmapped zero clusters if no backing file

2017-04-10 Thread Eric Blake
'qemu-img map' already coalesces information about unallocated clusters (those with status 0) and pure zero clusters (those with status BDRV_BLOCK_ZERO and no offset). Furthermore, all qcow2 images with no backing file already report all unallocated clusters (in the preallocation sense of