[OpenAFS-devel] afs and byte-range locking ideas

[Frank J. Cameron]

Nathan Neulinger wrote:

>Leif Johansson and I were discussing some possible ways of implementing
>this during LISA that should be relatively easy to implement (I think)
>at the client side and server.
>
>Here's the idea:
>
>Stage 1: Upgradable byte range locks at the client side
>(Client change only, assumes existing servers only)
>
>When a process on client requests a byte range lock, first attempt to
>get a full file lock on the server (if one has not already been obtained
>by this local client). If successful, locally attempt to grant the byte
>range lock.
>
>Gain: This allows multiple processes on a single host to use byte range
>locks locally, which will help multi-process apps work properly when
>components of the same app need to lock for synchronization within
>itself. 
>
The two biggest problems I have with AFS in my environment are:
    Multiple hosts accessing Office documents at the same time
    One host accessing an Outlook PST file

I'm no expert on AFS locking; although I have been digging through the 
code to try to learn how to fix those problems.  Your proposal sounds 
reasonable to me; I'm certainly willing to test if/when potential 
patches are available.

-frank