[PATCH 6.4 513/800] NFSv4.1: freeze the session table upon receiving NFS4ERR_BADSESSION

Greg Kroah-Hartman
2023-07-16T20:16:53Z

From: Olga Kornievskaia <kolga@netapp.com>

[ Upstream commit c907e72f58ed979a24a9fdcadfbc447c51d5e509 ]

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>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4proc.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d3665390c4cb8..9faba2dac11dd 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);
--
2.39.2