Coda File System

Re: Theory of writeback (without SHA-1 or other crypto)

From: Phil Nelson <>
Date: Sun, 25 Mar 2007 08:58:15 -0700
On Sunday 25 March 2007 07:07, wrote:
> This would probably work well for systems without mmap(),
> it is what you meant with "OS-specific"?
> Otherwise I fear that we'd miss possible modifications done via mmap().
> It may be used though as another "shortcut" check if there were no mmap()s.

On the systems that support mmap(), we can check the protection argument 
for the flag PROT_WRITE.  If it is mapped with write, the kernel module would
have to assume a write.  (I don't think we want to try to walk the buffer
cache in each supported system trying to find out if any of the pages were


Phil Nelson                       NetBSD:
e-mail:           Coda: 

Received on 2007-03-25 12:00:11