Okay, thanks! I think I missed that explanation yesterday.
On Wed, Sep 11, 2013 at 9:13 AM, Myklebust, Trond
<Trond.Myklebust@xxxxxxxxxx> wrote:
> On Wed, 2013-09-11 at 08:59 -0400, Anna Schumaker wrote:
>> Do we need to do a get_rpccred() after looking up the machine cred in
>> nfs_alloc_client()? Where does our guaranteed reference come from?
>
> See my comment to Dros' first patchset yesterday. In the case of
> SP4_MACH_CRED, we cannot change the machine credential, since the state
> protection is completely tied to that credential. In fact if you look at
> the current code, we only actually free the cl_machine_cred in
> nfs_free_client().
>
> For that reason, it is safe to assume that it is available for the
> duration of the RPC call. Of course, rpc_task_set_rpc_message() will
> also take a reference, but that too is redundant in this particular
> case.
>
> Cheers
> Trond
>
>> Anna
>>
>>
>>
>> On Tue, Sep 10, 2013 at 6:44 PM, Weston Andros Adamson
>> <dros@xxxxxxxxxx> wrote:
>> The cl_machine_cred doesn't need to be reference counted here
>> -
>> a reference is held is for the lifetime of the struct
>> nfs_client.
>> Also, no need to put_rpccred the rpc_message.rpc_cred.
>>
>> Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxx>
>> ---
>> fs/nfs/nfs4_fs.h | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
>> index f520a11..07a8aa9 100644
>> --- a/fs/nfs/nfs4_fs.h
>> +++ b/fs/nfs/nfs4_fs.h
>> @@ -279,10 +279,10 @@ _nfs4_state_protect(struct nfs_client
>> *clp, unsigned long sp4_mode,
>> if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
>> spin_lock(&clp->cl_lock);
>> if (clp->cl_machine_cred != NULL)
>> - newcred =
>> get_rpccred(clp->cl_machine_cred);
>> + /* don't call get_rpccred on the
>> machine cred -
>> + * a reference will be held for life
>> of clp */
>> + newcred = clp->cl_machine_cred;
>> spin_unlock(&clp->cl_lock);
>> - if (msg->rpc_cred)
>> - put_rpccred(msg->rpc_cred);
>> msg->rpc_cred = newcred;
>>
>> flavor =
>> clp->cl_rpcclient->cl_auth->au_flavor;
>> --
>> 1.7.12.4 (Apple Git-37)
>>
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>>
>
> --
> Trond Myklebust
> Linux NFS client maintainer
>
> NetApp
> Trond.Myklebust@xxxxxxxxxx
> www.netapp.com
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