From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
We used to do this before 3453d5708b33, but this was changed to better
handle the NFS4ERR_SEQ_MISORDERED error code. This commit fixed the slot
re-use case when the server doesn't receive the interrupted operation,
but if the server does receive the operation then it could still end up
replying to the client with mis-matched operations from the reply cache.
We can fix this by sending a SEQUENCE to the server while recovering from
a SEQ_MISORDERED error when we detect that we are in an interrupted slot
situation.
Fixes: 3453d5708b33 (NFSv4.1: Avoid false retries when RPC calls are interrupted)
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e32717fd1169..5de41a5772f0 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -774,6 +774,14 @@ static void nfs4_slot_sequence_acked(struct nfs4_slot *slot,
slot->seq_nr_last_acked = seqnr;
}
+static void nfs4_probe_sequence(struct nfs_client *client, const struct cred *cred,
+ struct nfs4_slot *slot)
+{
+ struct rpc_task *task = _nfs41_proc_sequence(client, cred, slot, true);
+ if (!IS_ERR(task))
+ rpc_wait_for_completion_task(task);
+}
+
static int nfs41_sequence_process(struct rpc_task *task,
struct nfs4_sequence_res *res)
{
@@ -790,6 +798,7 @@ static int nfs41_sequence_process(struct rpc_task *task,
goto out;
session = slot->table->session;
+ clp = session->clp;
trace_nfs4_sequence_done(session, res);
@@ -804,7 +813,6 @@ static int nfs41_sequence_process(struct rpc_task *task,
nfs4_slot_sequence_acked(slot, slot->seq_nr);
/* Update the slot's sequence and clientid lease timer */
slot->seq_done = 1;
- clp = session->clp;
do_renew_lease(clp, res->sr_timestamp);
/* Check sequence flags */
nfs41_handle_sequence_flag_errors(clp, res->sr_status_flags,
@@ -852,10 +860,15 @@ static int nfs41_sequence_process(struct rpc_task *task,
/*
* Were one or more calls using this slot interrupted?
* If the server never received the request, then our
- * transmitted slot sequence number may be too high.
+ * transmitted slot sequence number may be too high. However,
+ * if the server did receive the request then it might
+ * accidentally give us a reply with a mismatched operation.
+ * We can sort this out by sending a lone sequence operation
+ * to the server on the same slot.
*/
if ((s32)(slot->seq_nr - slot->seq_nr_last_acked) > 1) {
slot->seq_nr--;
+ nfs4_probe_sequence(clp, task->tk_msg.rpc_cred, slot);
goto retry_nowait;
}
/*
--
2.27.0
