Re: [PATCH v2] nfsd: nfsd4_cb_sequence_done() for processing more cb errors

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Jun 24, 2015 at 09:10:55AM +0800, Kinglong Mee wrote:
> On 6/24/2015 5:34 AM, J. Bruce Fields wrote:
> > On Wed, Jun 17, 2015 at 09:57:34PM +0800, Kinglong Mee wrote:
> >> When testing pnfs layout, nfsd got error NFS4ERR_SEQ_MISORDERED.
> >> It is caused by nfs return NFS4ERR_DELAY before validate_seqid(),
> >> don't update the sequnce id, but nfsd updates the sequnce id !!!
> >>
> >> According to RFC5661 20.9.3,
> >> " If CB_SEQUENCE returns an error, then the state of the slot
> >> (sequence ID, cached reply) MUST NOT change."
> >>
> >> This patch introduce a new helper nfsd4_cb_sequence_done() for
> >> processing more callback errors as client.
> >>
> >> v2, 
> >> thanks Christoph's advice of adding a helper process errors as client
> > 
> > Thanks, could you rebase this on top of my for-4.2 branch?  (I already
> > took your earlier patch.)  Also:
> 
> Got it.
> 
> > 
> >> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
> >> ---
> >>  fs/nfsd/nfs4callback.c | 122 +++++++++++++++++++++++++++++++++++++------------
> >>  fs/nfsd/state.h        |   1 +
> >>  2 files changed, 93 insertions(+), 30 deletions(-)
> >>
> >> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> >> index ce8d3f2..6fce478 100644
> >> --- a/fs/nfsd/nfs4callback.c
> >> +++ b/fs/nfsd/nfs4callback.c
> > ...
> >> @@ -874,6 +874,11 @@ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
> >>  	struct nfs4_client *clp = cb->cb_clp;
> >>  	u32 minorversion = clp->cl_minorversion;
> >>  
> >> +	/*
> >> +	 * cb_seq_status is only set in decode_cb_sequence4res,
> >> +	 * and so will remain 1 if an rpc level failure occurs.
> >> +	 */
> >> +	cb->cb_seq_status = 1;
> > 
> > Isn't that a valid error code?  OK, I guess NFS4ERR_PERM isn't a legal
> > SEQUENCE return.  Still, -1 might make this a bit more obvious.
> 
> No, error code is a negative number, 1 is safe.
> Also, it is copied from client's error process in nfs41_sequence_done.

Doh, got it!

--b.