[OpenAFS] Solaris 10u6: ZFS cache?

Derrick Brashear shadow@gmail.com
Tue, 11 Nov 2008 18:03:32 -0500

>>>  o The ois_DisableAtime routine was trying to update
>>>  the inode. I skipped that part of the code. Is this
>>>  OK or not?   Is there another way to update the flag?
> What is this code trying to do? Is it trying to say don't
> update the atime of the cache file as this improves performance?

That's the goal. The atime on cache inodes is meaningless. They aren't
real files.

>> Perhaps we should use values just shy of 0xffffffff.
> Yes that would work.
> It also looks like ZFS is storing the object ID as the
> inode which can be obtained from a stat() with -D_FILE_OFFSET_BITS=64

Can we leverage that? Actually, if we do, we have the issue that we
can no longer use tmpfs as cache, which I assume with your first patch
we can.

> And it looks like the vnode associated with an object can be obtained
> via a vfs_vget(vfs, vnode **, fid)
> The fid can have the object ID.
> So it looks like if there was a ZfsSOpen much like there is a
> XvfsOpen, if could get constructe an fid, and called VFS_VGET
> to get the vnode. In this case then the AFS_CACHE_VNODE_PATH
> would not be needed.