Mention about the possibilities of using staging_target_path at NodeStage

[humblec]

At present, it is unclear to SP that, how to use staging_target_path and the possibilities of using the same. This patch add more details on staging target path and its usage.

Fix # https://github.com/container-storage-interface/spec/issues/385

Signed-off-by: Humble Chirammal [email protected]

[humblec]

/assign @msau42

[shay-berman]

I think its a good clarification. We actually use the staging target path to store metadata file (with the discovered multipath device), in order to have that metadata during the NodePublishVolume(uses the metadata file to operate the l mkfs+mount it to target path) and for NodeUnStage (uses the metadata to clean up the multipath device).

So I think its good clarification that staging_target_path can be used for CSI driver metadata for example.

[humblec]

@saad-ali

[msau42]

/assign @saad-ali

[humblec]

@saad-ali @msau42 can you please review ?

[saad-ali]

I have no objections to this. But please bring it up at the next CSI meeting, would be good to get more eyeballs on this before merge.