Re: [Qemu-devel] [PATCHv3 1.8 1/9] qemu-img: add support for skipping zeroes in input during convert

2013-12-05 Thread Stefan Hajnoczi
On Wed, Dec 04, 2013 at 05:51:20PM +0100, Peter Lieven wrote: > Am 04.12.2013 17:46, schrieb Stefan Hajnoczi: > > On Wed, Nov 27, 2013 at 11:07:01AM +0100, Peter Lieven wrote: > >> +/* If the output image is being created as a copy on write > >> + * image, assume tha

Re: [Qemu-devel] [PATCHv3 1.8 1/9] qemu-img: add support for skipping zeroes in input during convert

2013-12-04 Thread Peter Lieven
Am 04.12.2013 17:46, schrieb Stefan Hajnoczi: > On Wed, Nov 27, 2013 at 11:07:01AM +0100, Peter Lieven wrote: >> +/* If the output image is being created as a copy on write >> + * image, assume that sectors which are unallocated in the >> + * input im

Re: [Qemu-devel] [PATCHv3 1.8 1/9] qemu-img: add support for skipping zeroes in input during convert

2013-12-04 Thread Stefan Hajnoczi
On Wed, Nov 27, 2013 at 11:07:01AM +0100, Peter Lieven wrote: > +/* If the output image is being created as a copy on write > + * image, assume that sectors which are unallocated in the > + * input image are present in both the output's and input's >

Re: [Qemu-devel] [PATCHv3 1.8 1/9] qemu-img: add support for skipping zeroes in input during convert

2013-11-27 Thread Paolo Bonzini
Il 27/11/2013 11:07, Peter Lieven ha scritto: > we currently do not check if a sector is allocated during convert. > This means if a sector is unallocated that we allocate a bounce > buffer of zeroes, find out its zero later and do not write it > in the best case. In the worst case this can lead to

[Qemu-devel] [PATCHv3 1.8 1/9] qemu-img: add support for skipping zeroes in input during convert

2013-11-27 Thread Peter Lieven
we currently do not check if a sector is allocated during convert. This means if a sector is unallocated that we allocate a bounce buffer of zeroes, find out its zero later and do not write it in the best case. In the worst case this can lead to reading blocks from a raw device (like iSCSI) altough