[Lustre-discuss] What is the state of sub-tree locking?

[Andreas Dilger]

On 2012-09-09, at 11:34 PM, 李希 wrote:
> We are trying to figure out whether it is possible to build a client-side cache system over Lustre in order to speed up the perforamance of our applications. In this system, we need to protect cached files and directories from being changed by other clients. The per-file group lock may not be enough since we need to protect the whole namespace including metadatas. I think sub-tree locking may help a lot, though it is not designed for this purpose. Any way, may I ask what time can we expect sub-tree lock to be released? Is there any prototypical source codes?

There was no development work done for sub-tree locking for Lustre.  This was only a proposed feature, but it never started development.

Cheers, Andreas
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Andreas Dilger                       Whamcloud, Inc.
Principal Lustre Engineer            http://www.whamcloud.com/