[Lustre-devel] new to lustre and bug 18539
Oleg Drokin
Oleg.Drokin at Sun.COM
Fri May 22 08:25:41 PDT 2009
Hello!
On May 22, 2009, at 9:29 AM, James Simmons wrote:
>>> My second set of questions deals with osc_statfs*. From the notes
>>> in the bugzilla osc_statfs_interpret is a MDS side function.
>>> Looking at
>>> the code I noticed it is the call back to osc_statfs_async. Knowing
>>> that osc_statfs_async is a obd_ops and thus has a wrapper,
>>> obd_statfs_async.
>>> I scanning the code for this and noticed that this wrapper used
>>> with the
>>> proper obd_device for the osc was used in the lov layer. The two
>>> areas in
>>> the lov layer where lov_statfs_async and qos_statfs_update handled
>>> this.
>>> If I remember right this is on the client side of the code. Where
>>> does the
>>> mds fit into this? Lov_statfs_async is for when the client queries
>>> data
>> MDS is a client to OSTs, that's why it has client bits to deal with
>> them
>> (LOV and OSCs).
> Because the lov is present also on the MDS as well as the client
> then the
> callback, aa->aa_oi->oi_cb_up, is going to depend on it being a MDS
> or a
> cleint. Correct or am I wrong?
Actually what I see in the code is LOV always assigns the same value,
so it
should be the same. On the other hand it is a possibility to pass down
such a callback
from a layer above LOV, then it might be different.
Bye,
Oleg
More information about the lustre-devel
mailing list