zfs code - Jul 2007 - Tracing znode_t from dnode_t

Hi,
    To get my understanding of zfs data structures correct, I need to
trace znode_t from given dnode_t. I came up with following trace, is
this correct?

dnote_t->dn_bonus->db_user_ptr points to corresponding znode_t

Is there any other(better) way to trace znode_t from dnode_t?

Cheers,
-Atul

> Hi,
>     To get my understanding of zfs data structures correct, I need to
> trace znode_t from given dnode_t. I came up with following trace, is
> this correct?
> 
> dnote_t->dn_bonus->db_user_ptr points to corresponding znode_t
That is right.
> Is there any other(better) way to trace znode_t from dnode_t?
No, from a dnode_t, you always go through the dmu_buf_impl_t to get to the
the znode_t. When you say better, what exactly are you looking for?
The other commonly accessed path of znode_t will be through vnode_t->v_data.

For a larger picture of how this all fits together, there is a nice
picture at http://www.opensolaris.org/os/community/zfs/structures/

- Vidya Sakar

Thanks Vidya for the confirmation. I was just trying to understand the
source code better :)
Cheers,
-Atul

On 7/26/07, Vidya Sakar N <Vidya.Sakar at sun.com>
wrote:
> > Hi,
> >     To get my understanding of zfs data structures correct, I need to
> > trace znode_t from given dnode_t. I came up with following trace, is
> > this correct?
> >
> > dnote_t->dn_bonus->db_user_ptr points to corresponding znode_t
>
> That is right.
>
> > Is there any other(better) way to trace znode_t from dnode_t?
>
> No, from a dnode_t, you always go through the dmu_buf_impl_t to get to the
> the znode_t. When you say better, what exactly are you looking for?
> The other commonly accessed path of znode_t will be through
vnode_t->v_data.
>
> For a larger picture of how this all fits together, there is a nice
> picture at http://www.opensolaris.org/os/community/zfs/structures/
>
> - Vidya Sakar
>

-- 
Atul Vidwansa
Cluster File Systems Inc.
http://www.clusterfs.com