Commit 913fadc5 authored by Anna Schumaker's avatar Anna Schumaker

NFS: Fix interrupted slots by sending a solo SEQUENCE operation

We used to do this before 3453d570, 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: 3453d570 (NFSv4.1: Avoid false retries when RPC calls are interrupted)
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent af667527
...@@ -774,6 +774,14 @@ static void nfs4_slot_sequence_acked(struct nfs4_slot *slot, ...@@ -774,6 +774,14 @@ static void nfs4_slot_sequence_acked(struct nfs4_slot *slot,
slot->seq_nr_last_acked = seqnr; 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, static int nfs41_sequence_process(struct rpc_task *task,
struct nfs4_sequence_res *res) struct nfs4_sequence_res *res)
{ {
...@@ -790,6 +798,7 @@ static int nfs41_sequence_process(struct rpc_task *task, ...@@ -790,6 +798,7 @@ static int nfs41_sequence_process(struct rpc_task *task,
goto out; goto out;
session = slot->table->session; session = slot->table->session;
clp = session->clp;
trace_nfs4_sequence_done(session, res); trace_nfs4_sequence_done(session, res);
...@@ -804,7 +813,6 @@ static int nfs41_sequence_process(struct rpc_task *task, ...@@ -804,7 +813,6 @@ static int nfs41_sequence_process(struct rpc_task *task,
nfs4_slot_sequence_acked(slot, slot->seq_nr); nfs4_slot_sequence_acked(slot, slot->seq_nr);
/* Update the slot's sequence and clientid lease timer */ /* Update the slot's sequence and clientid lease timer */
slot->seq_done = 1; slot->seq_done = 1;
clp = session->clp;
do_renew_lease(clp, res->sr_timestamp); do_renew_lease(clp, res->sr_timestamp);
/* Check sequence flags */ /* Check sequence flags */
nfs41_handle_sequence_flag_errors(clp, res->sr_status_flags, nfs41_handle_sequence_flag_errors(clp, res->sr_status_flags,
...@@ -852,10 +860,18 @@ static int nfs41_sequence_process(struct rpc_task *task, ...@@ -852,10 +860,18 @@ static int nfs41_sequence_process(struct rpc_task *task,
/* /*
* Were one or more calls using this slot interrupted? * Were one or more calls using this slot interrupted?
* If the server never received the request, then our * 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) { if ((s32)(slot->seq_nr - slot->seq_nr_last_acked) > 1) {
slot->seq_nr--; 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; goto retry_nowait;
} }
/* /*
......
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