From: Anna Schumaker Anna.Schumaker@Netapp.com
[ Upstream commit 913fadc5b105c3619d9e8d0fe8899ff1593cc737 ]
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@Netapp.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/nfs4proc.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index e32717fd1169a..2e2dac29a9e91 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_put_task_async(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 +860,18 @@ 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--; + if (task->tk_msg.rpc_proc != &nfs4_procedures[NFSPROC4_CLNT_SEQUENCE]) { + nfs4_probe_sequence(clp, task->tk_msg.rpc_cred, slot); + res->sr_slot = NULL; + } goto retry_nowait; } /*