On 5/6/24 2:04 PM, cel@xxxxxxxxxx wrote:
From: Chuck Lever <chuck.lever@xxxxxxxxxx>
We've discovered that delivering a CB_OFFLOAD operation can be
unreliable in some pretty unremarkable situations,
Since the fore and back channel use the same connection so I assume
this is not a connection related problem.
Sounds like this is a bug that we should find and fix if possible
instead of work around it. Do you know any scenarios where the
CB_OFFLOAD operation is unreliable?
-Dai
and the Linux
NFS client does not yet support sending an OFFLOAD_STATUS
operation to probe whether an asynchronous COPY operation has
finished. On Linux NFS clients, COPY can hang until manually
interrupted.
I've tried a couple of remedies, but so far the side-effects are
worse than the disease. For now, force COPY operations to be
synchronous so that the use of CB_OFFLOAD is avoided entirely.
I have some patches that add an OFFLOAD_STATUS implementation to the
Linux NFS client, but that is not likely to fix older clients.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfs4proc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index ea3cc3e870a7..12722c709cc6 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1807,6 +1807,13 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
__be32 status;
struct nfsd4_copy *async_copy = NULL;
+ /*
+ * Currently, async COPY is not reliable. Force all COPY
+ * requests to be synchronous to avoid client application
+ * hangs waiting for completion.
+ */
+ nfsd4_copy_set_sync(copy, true);
+
copy->cp_clp = cstate->clp;
if (nfsd4_ssc_is_inter(copy)) {
trace_nfsd_copy_inter(copy);
base-commit: 939cb14d51a150e3c12ef7a8ce0ba04ce6131bd2
