mdadm Consistency Policy initialization

mdadm Consistency Policy initialization

[Jes Sorensen]

Hi Artur,

In 5308f11727b889965efe5ac0e854d197c2b51f6d you introduced struct 
mdinfo: enum consistency_policy, but in mdadm.c you initialize it to 
UnSet which isn't part of the enum.

Is there any actual difference between CONSISTENCY_POLICY_UNKNOWN and 
UnSet? It seems suboptimal to mix and match within the enum like this, 
and if CONSISTENCY_POLICY_UNKNOWN does the job, couldn't we just 
initialize with that?

Cheers,
Jes

Re: mdadm Consistency Policy initialization

[Artur Paszkiewicz]

On 04/18/2017 06:50 PM, Jes Sorensen wrote:
> Hi Artur,
> 
> In 5308f11727b889965efe5ac0e854d197c2b51f6d you introduced struct mdinfo: enum consistency_policy, but in mdadm.c you initialize it to UnSet which isn't part of the enum.
> 
> Is there any actual difference between CONSISTENCY_POLICY_UNKNOWN and UnSet? It seems suboptimal to mix and match within the enum like this, and if CONSISTENCY_POLICY_UNKNOWN does the job, couldn't we just initialize with that?

Hi Jes,

The "enum consistency_policy" and "mapping_t consistency_policies[]"
represent values that can appear in sysfs. md/consistency_policy can be
"unknown" when the array is inactive. On the other hand, UnSet just
means that the --consistency-policy= parameter was not provided by the
user. I wanted to differentiate between these two cases. If you think
this is redundant I can change it and use CONSISTENCY_POLICY_UNKNOWN
instead, this should be straightforward.

Thanks,
Artur

Re: mdadm Consistency Policy initialization

[Jes Sorensen]

On 04/19/2017 06:29 AM, Artur Paszkiewicz wrote:
> On 04/18/2017 06:50 PM, Jes Sorensen wrote:
>> Hi Artur,
>>
>> In 5308f11727b889965efe5ac0e854d197c2b51f6d you introduced struct mdinfo: enum consistency_policy, but in mdadm.c you initialize it to UnSet which isn't part of the enum.
>>
>> Is there any actual difference between CONSISTENCY_POLICY_UNKNOWN and UnSet? It seems suboptimal to mix and match within the enum like this, and if CONSISTENCY_POLICY_UNKNOWN does the job, couldn't we just initialize with that?
>
> Hi Jes,
>
> The "enum consistency_policy" and "mapping_t consistency_policies[]"
> represent values that can appear in sysfs. md/consistency_policy can be
> "unknown" when the array is inactive. On the other hand, UnSet just
> means that the --consistency-policy= parameter was not provided by the
> user. I wanted to differentiate between these two cases. If you think
> this is redundant I can change it and use CONSISTENCY_POLICY_UNKNOWN
> instead, this should be straightforward.

Hi Artur,

I would prefer to either use CONSISTENCY_POLICY_UNKNOWN or introduce a 
new state within the enum so we don't cross pollute the namespace.

Cheers,
Jes

Re: mdadm Consistency Policy initialization

[Jes Sorensen]

On 04/19/2017 06:29 AM, Artur Paszkiewicz wrote:
> On 04/18/2017 06:50 PM, Jes Sorensen wrote:
>> Hi Artur,
>>
>> In 5308f11727b889965efe5ac0e854d197c2b51f6d you introduced struct mdinfo: enum consistency_policy, but in mdadm.c you initialize it to UnSet which isn't part of the enum.
>>
>> Is there any actual difference between CONSISTENCY_POLICY_UNKNOWN and UnSet? It seems suboptimal to mix and match within the enum like this, and if CONSISTENCY_POLICY_UNKNOWN does the job, couldn't we just initialize with that?
>
> Hi Jes,
>
> The "enum consistency_policy" and "mapping_t consistency_policies[]"
> represent values that can appear in sysfs. md/consistency_policy can be
> "unknown" when the array is inactive. On the other hand, UnSet just
> means that the --consistency-policy= parameter was not provided by the
> user. I wanted to differentiate between these two cases. If you think
> this is redundant I can change it and use CONSISTENCY_POLICY_UNKNOWN
> instead, this should be straightforward.

Hi Artur,

I made some changes to map_name() and noticed that you already there 
default to CONSISTENCY_POLICY_UNKNOWN if it returns UnSet in 
sysfs_read(). However given that you do a lot of checks manually outside 
of sysfs.c, I dind't change the code there for now. I think we the 
change I made to map_name() it should be possible to simply a bunch of 
that checking code.

Cheers,
Jes

Re: mdadm Consistency Policy initialization

[Artur Paszkiewicz]

On 04/20/2017 06:08 PM, Jes Sorensen wrote:
> On 04/19/2017 06:29 AM, Artur Paszkiewicz wrote:
>> On 04/18/2017 06:50 PM, Jes Sorensen wrote:
>>> Hi Artur,
>>>
>>> In 5308f11727b889965efe5ac0e854d197c2b51f6d you introduced struct mdinfo: enum consistency_policy, but in mdadm.c you initialize it to UnSet which isn't part of the enum.
>>>
>>> Is there any actual difference between CONSISTENCY_POLICY_UNKNOWN and UnSet? It seems suboptimal to mix and match within the enum like this, and if CONSISTENCY_POLICY_UNKNOWN does the job, couldn't we just initialize with that?
>>
>> Hi Jes,
>>
>> The "enum consistency_policy" and "mapping_t consistency_policies[]"
>> represent values that can appear in sysfs. md/consistency_policy can be
>> "unknown" when the array is inactive. On the other hand, UnSet just
>> means that the --consistency-policy= parameter was not provided by the
>> user. I wanted to differentiate between these two cases. If you think
>> this is redundant I can change it and use CONSISTENCY_POLICY_UNKNOWN
>> instead, this should be straightforward.
> 
> Hi Artur,
> 
> I made some changes to map_name() and noticed that you already there default to CONSISTENCY_POLICY_UNKNOWN if it returns UnSet in sysfs_read(). However given that you do a lot of checks manually outside of sysfs.c, I dind't change the code there for now. I think we the change I made to map_name() it should be possible to simply a bunch of that checking code.

Hi Jes,

It does seem to be better this way. I'll send a patch that removes using
UnSet from all consistency policy related places soon.

Thanks,
Artur

Re: mdadm Consistency Policy initialization

[Jes Sorensen]

On 04/24/2017 06:07 AM, Artur Paszkiewicz wrote:
> On 04/20/2017 06:08 PM, Jes Sorensen wrote:
>> On 04/19/2017 06:29 AM, Artur Paszkiewicz wrote:
>>> Hi Jes,
>>>
>>> The "enum consistency_policy" and "mapping_t consistency_policies[]"
>>> represent values that can appear in sysfs. md/consistency_policy can be
>>> "unknown" when the array is inactive. On the other hand, UnSet just
>>> means that the --consistency-policy= parameter was not provided by the
>>> user. I wanted to differentiate between these two cases. If you think
>>> this is redundant I can change it and use CONSISTENCY_POLICY_UNKNOWN
>>> instead, this should be straightforward.
>>
>> Hi Artur,
>>
>> I made some changes to map_name() and noticed that you already there default to CONSISTENCY_POLICY_UNKNOWN if it returns UnSet in sysfs_read(). However given that you do a lot of checks manually outside of sysfs.c, I dind't change the code there for now. I think we the change I made to map_name() it should be possible to simply a bunch of that checking code.
>
> Hi Jes,
>
> It does seem to be better this way. I'll send a patch that removes using
> UnSet from all consistency policy related places soon.

Awesome!

I am glad you like it.

Jes