Coda File System

Re: Cache Overflow

From: Greg Troxel <gdt_at_ir.bbn.com>
Date: 02 May 2004 15:33:05 -0400
Jan Harkes <jaharkes_at_cs.cmu.edu> writes:

> That is because we don't intercept write calls in the kernel module.
> When you copy a file into /coda, the only thing venus gets to see is,
> 
>     CREATE file
> 	(creates a 0-length file, no problem here)
> 
>     OPEN file for writing
> 	(sure, we hand a reference to the file to the kernel module)
> 
>     cp program writes, and writes, and writes
> 
>     CLOSE file
> 	(OMG we exceeded the available cache space)

It would be cool if venus somehow communicated a size limit to the
kernel (set by server admin?), and the kernel write call had a hook to
check that, and send E2BIG or something to the process when a too-big
write happened.  (I don't mean pushing the write calls through venus,
just in-kernel size checking on write.)

-- 
        Greg Troxel <gdt_at_ir.bbn.com>
Received on 2004-05-02 15:38:03