From: Chuck Lever <[email protected]>
Replace open-coded encoding logic with the use of conventional XDR
utility functions. Add a tracepoint to make replays observable in
field troubleshooting situations.
The WARN_ON is removed. A stack trace is of little use, as there is
only one call site for nfsd4_encode_replay(), and a buffer length
shortage here is nearly impossible.
Signed-off-by: Chuck Lever <[email protected]>
---
fs/nfsd/nfs4xdr.c | 29 +++++++++++++----------------
fs/nfsd/trace.h | 18 ++++++++++++++++++
2 files changed, 31 insertions(+), 16 deletions(-)
Neil and Jeff have now done the hard part. Here's a simple clean up
for the NFSv4 stateowner replay code path.
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 9e8f230fc96e..fac938f563ad 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -5732,27 +5732,24 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
rqstp->rq_next_page = xdr->page_ptr + 1;
}
-/*
- * Encode the reply stored in the stateowner reply cache
- *
- * XDR note: do not encode rp->rp_buflen: the buffer contains the
- * previously sent already encoded operation.
+/**
+ * nfsd4_encode_replay - encode a result stored in the stateowner reply cache
+ * @xdr: send buffer's XDR stream
+ * @op: operation being replayed
+ *
+ * @op->replay->rp_buf contains the previously-sent already-encoded result.
*/
-void
-nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
+void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
{
- __be32 *p;
struct nfs4_replay *rp = op->replay;
- p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
- if (!p) {
- WARN_ON_ONCE(1);
- return;
- }
- *p++ = cpu_to_be32(op->opnum);
- *p++ = rp->rp_status; /* already xdr'ed */
+ trace_nfsd_stateowner_replay(op->opnum, rp);
- p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
+ if (xdr_stream_encode_u32(xdr, op->opnum) != XDR_UNIT)
+ return;
+ if (xdr_stream_encode_be32(xdr, rp->rp_status) != XDR_UNIT)
+ return;
+ xdr_stream_encode_opaque_fixed(xdr, rp->rp_buf, rp->rp_buflen);
}
void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index d8e56268a250..e545e92c4408 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -696,6 +696,24 @@ DEFINE_EVENT(nfsd_stid_class, nfsd_stid_##name, \
DEFINE_STID_EVENT(revoke);
+TRACE_EVENT(nfsd_stateowner_replay,
+ TP_PROTO(
+ u32 opnum,
+ const struct nfs4_replay *rp
+ ),
+ TP_ARGS(opnum, rp),
+ TP_STRUCT__entry(
+ __field(unsigned long, status)
+ __field(u32, opnum)
+ ),
+ TP_fast_assign(
+ __entry->status = be32_to_cpu(rp->rp_status);
+ __entry->opnum = opnum;
+ ),
+ TP_printk("opnum=%u status=%lu",
+ __entry->opnum, __entry->status)
+);
+
TRACE_EVENT_CONDITION(nfsd_seq4_status,
TP_PROTO(
const struct svc_rqst *rqstp,