On Thursday, 2020-02-20 at 10:36:04 -06, Eric Blake wrote: > On 2/20/20 10:06 AM, Max Reitz wrote: >> From: David Edmondson <david.edmond...@oracle.com> >> >> In many cases the target of a convert operation is a newly provisioned >> target that the user knows is blank (reads as zero). In this situation >> there is no requirement for qemu-img to wastefully zero out the entire >> device. >> >> Add a new option, --target-is-zero, allowing the user to indicate that >> an existing target device will return zeros for all reads. >> >> Signed-off-by: David Edmondson <david.edmond...@oracle.com> >> Message-Id: <20200205110248.2009589-2-david.edmond...@oracle.com> >> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> >> Reviewed-by: Eric Blake <ebl...@redhat.com> >> Signed-off-by: Max Reitz <mre...@redhat.com> >> --- >> docs/interop/qemu-img.rst | 9 ++++++++- >> qemu-img-cmds.hx | 4 ++-- >> qemu-img.c | 26 +++++++++++++++++++++++--- >> 3 files changed, 33 insertions(+), 6 deletions(-) >> >> diff --git a/docs/interop/qemu-img.rst b/docs/interop/qemu-img.rst >> index 42e4451db4..5f40137c10 100644 >> --- a/docs/interop/qemu-img.rst >> +++ b/docs/interop/qemu-img.rst >> @@ -214,6 +214,13 @@ Parameters to convert subcommand: >> will still be printed. Areas that cannot be read from the source will be >> treated as containing only zeroes. >> >> +.. option:: --target-is-zero >> + >> + Assume that reading the destination image will always return >> + zeros. This parameter is mutually exclusive with a destination image > > Late tweak now that this is in a pull request, so we may want a followup > patch, but: > > The image doesn't always return zeros after we write to it, maybe we > should tweak this sentence: > > Assume that reading the destination image will initially return all zeros.
I will send a patch for this. > Also, my earlier comment about 'zeroes' one line before 'zeros' still > applies - although both spellings are valid, we look inconsistent when > we can't make up our mind within two adjacent paragraphs. If we can agree on one of "zeros" or "zeroes" then I'm happy to send a patch making it consistent everywhere. I think that given there are existing functions with "zeroes" in the name, I'd be inclined to go that way. dme. -- Why stay in college? Why go to night school?