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

[Derek Atkins]

"Cameron, Frank" <Cameron@ctc.com> writes:

> >As was pointed out, do to the way AFS File Caching works, you will
> >"never" get AFS to work with your former problem (multiple hosts
> >accesing an Office document).  Having a single host access an
> >Outlook file, however, we should be able to do (multiple locks on
> >one client).
> 
> Personally, I'm not concerned with multiple hosts both being able
> to modify a file.  Only that when one host opens the file a second
> host can't.  With an Office document on an NT, NetWare, or Samba
> server this works; the second person to open a file is told that the
> file is already open.  Currently in AFS, there is no warning given
> to the second user.

Ahh, that's what you mean.  Yes, this should be supported.  All that
has to happen is that client 1 requests a lock (any type of local
lock, byte-range or otherwise).  The client1 CM requests a file lock
from the server; if the lock is granted, then the CM provides the lock
to the requesting application.  When client 2 comes along, the server
(hopefully) wont let it lock the file (because the file is locked by
client 1).

> -frank

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
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