From: Anna Schumaker <Anna.Schumaker@Netapp.com> mainline inclusion from mainline-v5.8-rc6 commit 913fadc5b105c3619d9e8d0fe8899ff1593cc737 category: bugfix bugzilla: NA CVE: NA -------------------------------- 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> Conflicts: fs/nfs/nfs4proc.c Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/nfs/nfs4proc.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index e30df289e9610..ffb7a6e7f5664 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -757,6 +757,15 @@ 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, + struct rpc_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) { @@ -773,6 +782,7 @@ static int nfs41_sequence_process(struct rpc_task *task, goto out; session = slot->table->session; + clp = session->clp; trace_nfs4_sequence_done(session, res); @@ -787,7 +797,6 @@ 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, @@ -835,10 +844,18 @@ 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; } /* -- 2.25.1