[RFC,3/7] docs: add lazy refcounts bit to qcow2 specification

Submitted by Stefan Hajnoczi on June 22, 2012, 3:08 p.m.

Details

Message ID 1340377726-5896-4-git-send-email-stefanha@linux.vnet.ibm.com
State New
Headers show

Commit Message

Stefan Hajnoczi June 22, 2012, 3:08 p.m.
The lazy refcounts bit indicates that this image can take advantage of
the dirty bit and that refcount updates can be postponed.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 docs/specs/qcow2.txt |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Kevin Wolf June 25, 2012, 2:35 p.m.
Am 22.06.2012 17:08, schrieb Stefan Hajnoczi:
> The lazy refcounts bit indicates that this image can take advantage of
> the dirty bit and that refcount updates can be postponed.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
> ---
>  docs/specs/qcow2.txt |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt
> index 3a789ce..8b2c0eb 100644
> --- a/docs/specs/qcow2.txt
> +++ b/docs/specs/qcow2.txt
> @@ -85,7 +85,11 @@ in the description of a field.
>                      Bitmask of compatible features. An implementation can
>                      safely ignore any unknown bits that are set.
>  
> -                    Bits 0-63:  Reserved (set to 0)
> +                    Bit 0: Lazy refcounts bit.  If this bit is set then lazy
> +                           refcount updates can be used.  This means postponing
> +                           marking the image file dirty and postponing refcount
> +                           metadata updates.
> +                    Bits 1-63:  Reserved (set to 0)

Please keep the formatting consistent: The description for bit 0 should
be indented to the same level as "Reserved", and an empty line should be
left between each description.

Regarding indentation, the same applies to patch 1.

Kevin
Stefan Hajnoczi June 25, 2012, 3:53 p.m.
On Mon, Jun 25, 2012 at 3:35 PM, Kevin Wolf <kwolf@redhat.com> wrote:
> Am 22.06.2012 17:08, schrieb Stefan Hajnoczi:
>> The lazy refcounts bit indicates that this image can take advantage of
>> the dirty bit and that refcount updates can be postponed.
>>
>> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
>> ---
>>  docs/specs/qcow2.txt |    6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt
>> index 3a789ce..8b2c0eb 100644
>> --- a/docs/specs/qcow2.txt
>> +++ b/docs/specs/qcow2.txt
>> @@ -85,7 +85,11 @@ in the description of a field.
>>                      Bitmask of compatible features. An implementation can
>>                      safely ignore any unknown bits that are set.
>>
>> -                    Bits 0-63:  Reserved (set to 0)
>> +                    Bit 0: Lazy refcounts bit.  If this bit is set then lazy
>> +                           refcount updates can be used.  This means postponing
>> +                           marking the image file dirty and postponing refcount
>> +                           metadata updates.
>> +                    Bits 1-63:  Reserved (set to 0)
>
> Please keep the formatting consistent: The description for bit 0 should
> be indented to the same level as "Reserved", and an empty line should be
> left between each description.
>
> Regarding indentation, the same applies to patch 1.

Sorry, the formatting wasn't obvious to me.  Will fix.

Stefan

Patch hide | download patch | download mbox

diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt
index 3a789ce..8b2c0eb 100644
--- a/docs/specs/qcow2.txt
+++ b/docs/specs/qcow2.txt
@@ -85,7 +85,11 @@  in the description of a field.
                     Bitmask of compatible features. An implementation can
                     safely ignore any unknown bits that are set.
 
-                    Bits 0-63:  Reserved (set to 0)
+                    Bit 0: Lazy refcounts bit.  If this bit is set then lazy
+                           refcount updates can be used.  This means postponing
+                           marking the image file dirty and postponing refcount
+                           metadata updates.
+                    Bits 1-63:  Reserved (set to 0)
 
          88 -  95:  autoclear_features
                     Bitmask of auto-clear features. An implementation may only