Libguestfs - Jun 2018 - Re: [PATCH] v2v: rhv-upload-plugin: Fix name error

http was missing in emulate_zero, so the code would fail with NameError.
This can happen only when communicating with old imageio versions not
supporting the "zero" feature.

Testing with qemu-img 2.12 show that we never send emulated zero request
because of the highestwrite mechanism, but it can break with older
qemu-img-rhev used on RHEL.
---
 v2v/rhv-upload-plugin.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
index 2eec375f7..0f6b31e67 100644
--- a/v2v/rhv-upload-plugin.py
+++ b/v2v/rhv-upload-plugin.py
@@ -338,6 +338,8 @@ def zero(h, count, offset, may_trim):
     r.read()
 
 def emulate_zero(h, count, offset):
+    http = h['http']
+
     # qemu-img convert starts by trying to zero/trim the whole device.
     # Since we've just created a new disk it's safe to ignore these
     # requests as long as they are smaller than the highest write seen.
-- 
2.17.1

On Mon, Jun 25, 2018 at 8:30 PM Nir Soffer <nirsof@gmail.com> wrote:
> http was missing in emulate_zero, so the code would fail with NameError.
> This can happen only when communicating with old imageio versions not
> supporting the "zero" feature.
>
> Testing with qemu-img 2.12 show that we never send emulated zero request
> because of the highestwrite mechanism, but it can break with older
> qemu-img-rhev used on RHEL.
> ---
>  v2v/rhv-upload-plugin.py | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
> index 2eec375f7..0f6b31e67 100644
> --- a/v2v/rhv-upload-plugin.py
> +++ b/v2v/rhv-upload-plugin.py
> @@ -338,6 +338,8 @@ def zero(h, count, offset, may_trim):
>      r.read()
>
>  def emulate_zero(h, count, offset):
> +    http = h['http']
>
After some more cleanup, I found that we are missing also "transfer"
here.
I'll send a fixed patch.

> +
>      # qemu-img convert starts by trying to zero/trim the whole device.
>      # Since we've just created a new disk it's safe to ignore
these
>      # requests as long as they are smaller than the highest write seen.
> --
> 2.17.1
>
>

On Mon, Jun 25, 2018 at 8:43 PM Nir Soffer <nsoffer@redhat.com> wrote:
> On Mon, Jun 25, 2018 at 8:30 PM Nir Soffer <nirsof@gmail.com> wrote:
>
>> http was missing in emulate_zero, so the code would fail with
NameError.
>> This can happen only when communicating with old imageio versions not
>> supporting the "zero" feature.
>>
>> Testing with qemu-img 2.12 show that we never send emulated zero
request
>> because of the highestwrite mechanism, but it can break with older
>> qemu-img-rhev used on RHEL.
>> ---
>>  v2v/rhv-upload-plugin.py | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
>> index 2eec375f7..0f6b31e67 100644
>> --- a/v2v/rhv-upload-plugin.py
>> +++ b/v2v/rhv-upload-plugin.py
>> @@ -338,6 +338,8 @@ def zero(h, count, offset, may_trim):
>>      r.read()
>>
>>  def emulate_zero(h, count, offset):
>> +    http = h['http']
>>
>
> After some more cleanup, I found that we are missing also
"transfer" here.
> I'll send a fixed patch.
>
Fixed in https://www.redhat.com/archives/libguestfs/2018-June/msg00118.html

>
>
>> +
>>      # qemu-img convert starts by trying to zero/trim the whole device.
>>      # Since we've just created a new disk it's safe to ignore
these
>>      # requests as long as they are smaller than the highest write
seen.
>> --
>> 2.17.1
>>
>>