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From:   Olga Kornievskaia <olga.kornievskaia@gmail.com>
To:     trond.myklebust@hammerspace.com, anna.schumaker@netapp.com
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 1/1] NFSv4.1: freeze the session table upon receiving NFS4ERR_BADSESSION
Date:   Sun, 18 Jun 2023 17:32:25 -0400
Message-Id: <20230618213225.75518-1-olga.kornievskaia@gmail.com>
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From: Olga Kornievskaia <kolga@netapp.com>

When the client received NFS4ERR_BADSESSION, it schedules recovery
and start the state manager thread which in turn freezes the
session table and does not allow for any new requests to use the
no-longer valid session. However, it is possible that before
the state manager thread runs, a new operation would use the
released slot that received BADSESSION and was therefore not
updated its sequence number. Such re-use of the slot can lead
the application errors.

Fixes: 5c441544f045 ("NFSv4.x: Handle bad/dead sessions correctly in nfs41_sequence_process()")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/nfs4proc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d3665390c4cb..9faba2dac11d 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -921,6 +921,7 @@ static int nfs41_sequence_process(struct rpc_task *task,
 out_noaction:
 	return ret;
 session_recover:
+	set_bit(NFS4_SLOT_TBL_DRAINING, &session->fc_slot_table.slot_tbl_state);
 	nfs4_schedule_session_recovery(session, status);
 	dprintk("%s ERROR: %d Reset session\n", __func__, status);
 	nfs41_sequence_free_slot(res);
-- 
2.39.1