nvme-print-json: Add remaining feature fields print functions

[ikegami-t]

No description provided.

[igaw]

Could you split the change into two bits? One which updates the formatting/codying style and one which just adds the new code? It makes the review a bit simpler. Thanks!

[ikegami-t]

Thanks for your comment. Split the patch and added additional a patch to fix the get feature command mixed stdout and json outputs issue.
Note: Still the get feature command outputs d() and d_raw() to stdout and error to stderr so it will be fixed separately.

[ikegami-t]

Removed the patches below to the PRs #2090 and #2091 since not related to the json output changes.

1. 5cc7bac nvme: Change short option -o and -v duplicated to upper case
2. 10e9c65 doc: Change short option -o and -v duplicated to upper case
3. c2510ad completions: Change short option -o and -v duplicated to upper case
4. e98bc40 nvme: Change phy-rx-eom-log command to use NVME_ARGS instead

[igaw]

I was wondering if wouldn't make sense to just use r instead of root as variable name in the functions and the use obj_add_str(r, ..., ...) instead introducing a wrapper macro just for this. What do you think?

As this series is pretty big and I don't want to make you suffer too much by updating every patch again, you can just add a cleanup patch add the end of the series, that is fine with me.

[ikegami-t]

Just fixed by the commit 6575bf3.

[igaw]

The feature output is getting closer to be valid JSON:

./nvme get-feature /dev/nvme0 -o json

{
  "Feature":"0x01",
  "Name":"Arbitration",
  "Current":"0x03030302"
}
{
  "Feature":"0x02",
  "Name":"Power Management",
  "Current":"0x00000003"
}
{
  "Error":"get-feature:0x03 (LBA Range Type): "
}
{
  "Error":"Invalid Namespace or Format: The namespace or the format of that namespace is invalid",
  "Type":"nvme",
  "Value":16395
}
{
  "Feature":"0x04",
  "Name":"Temperature Threshold",
  "Current":"0x00000162"
}
{
  "Error":"get-feature:0x05 (Error Recovery): "
}
{
  "Error":"Invalid Namespace or Format: The namespace or the format of that namespace is invalid",
  "Type":"nvme",
  "Value":16395
}
{
  "Feature":"0x06",
  "Name":"Volatile Write Cache",
  "Current":"0x00000001"
}

We need to figure out how handle the error case above and all features should be reported in an array.

There problem is the show_feature API is not really good for the JSON case. Maybe we need to split into show_feature_init, show_feature and show_feature_finish calls. The show_feature_init callback would allow the JSON code to allocate the array and then the pointer is handed into the show_feature function for every single invocation. show_feature_finish allows the JSON code then to print the result in one go.

[ikegami-t]

Rebased with the master and fixed some conflicts.

[ikegami-t]

Noted about the show_feature API problem. Yes I thought also to use the global variable root json object in nvme-print-json to resolved the issue. Anyway later will do consider the suggestion also. Thank you.

[igaw]

Thanks a lot.