mdraid: Add 'auto' and multiple devices support to parameter md_dev

[Damenly]

This commit allows the value 'auto' or multiple devices separated by space are set in parameter md_dev.

When 'auto' is assigned, mdraid RA will try to get all md arrays from mdraid_conf then assemble them automatically.
If multiple devices are assigned e.g. '/dev/md2 /dev/md3', the RA will try to assemble them.

The single device syntax is same as the original.

To keep the code and logic simple, global varaiable RAIDDEVS is introduced to record md devices. All entry functions mdraid_(stop|start|mintor) are renamed to mdraid_(stop|start|mintor)one which are called by new function forall(). In forall(), md_dev and devs are used by mdraid(stop|start|mintor)_one during iterating RAIDDEVS.
The original mdraid_stop_one is renamed to mdraid_stop_array for naming consistency.

Related: #1800

[Damenly]

Hmmm. It seems Jenkins is broken.

[oalbrigt]

We might need some more checks, so I will leave this open for 1-2 weeks to let the developer of the agent review it.

[Damenly]

Hi. Any comment from the developers of the agent?

[varkoly]

Can someone fix jenkins?

[varkoly]

Hi. Any comment from the developers of the agent?

Sure. The change is pretty straightforward, and I've tested the following cases based on SLE 16 Beta3:

1. Set md_dev to 'auto'
   1.1 If some of the md arrays listed in $mdadm_conf are not cluster-md, unless force_clones is true, the start of the RA will return $OCF_ERR_CONFIGURED
   1.2 If all of the md arrays are in cluster-md type, they will be assembled one by one
   1.3 If some of the md arrays listed in $mdadm_conf are not able to be assembled, $OCF_ERR_GENERIC will be returned, like how single device parameter behaves
2. Set md_dev to multi deivces like '/dev/md3 /dev/md127', mostly like 'auto' is given :
   2.1 If some of these md arrays listed in $mdadm_conf are not cluster-md, unless force_clones is true, the start of the RA will return $OCF_ERR_CONFIGURED
   2.2 If all of these md arrays are in cluster-md type, they will be assembled one by one
   2.3 If some of the md arrays listed in $mdadm_conf are not able to be assembled, $OCF_ERR_GENERIC will be returned, like how single device parameter behaves
   2.4 If some of given md devices are not in $mdadm_conf, the RA will fail to start as $OCF_ERR_GENERIC.
3. Set md_dev to single device. It works as before the change.
4. Set md_dev to other meaningless strings, the start returns $OCF_ERR_ARGS as the original.

[mauelsha]

Ok with me, as it's optionally configurable (keyword 'auto') and doesn't change single array RA semantics.

[oalbrigt]

retest this please

[Damenly]

Ping. Can this PR be merged?

[oalbrigt]

Thanks.