[PATCH 1/2] NFSv4: Revert commit 5f83d86cf531d ("NFSv4.x: Fix wraparound issues..")

[PATCH 1/2] NFSv4: Revert commit 5f83d86cf531d ("NFSv4.x: Fix wraparound issues..")

[Trond Myklebust]

The correct behaviour for NFSv4 sequence IDs is to wrap around
to the value 0 after 0xffffffff.
See https://tools.ietf.org/html/rfc5661#section-2.10.6.1

Fixes: 5f83d86cf531d ("NFSv4.x: Fix wraparound issues when validing...")
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/callback_proc.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 3a49bb19ef07..ee81031cab29 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -428,11 +428,8 @@ validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot,
 		return htonl(NFS4ERR_SEQ_FALSE_RETRY);
 	}
 
-	/* Wraparound */
-	if (unlikely(slot->seq_nr == 0xFFFFFFFFU)) {
-		if (args->csa_sequenceid == 1)
-			return htonl(NFS4_OK);
-	} else if (likely(args->csa_sequenceid == slot->seq_nr + 1))
+	/* Note: wraparound relies on seq_nr being of type u32 */
+	if (likely(args->csa_sequenceid == slot->seq_nr + 1))
 		return htonl(NFS4_OK);
 
 	/* Misordered request */
-- 
2.17.1

[PATCH 2/2] NFSv4: Fix a typo in nfs41_sequence_process

[Trond Myklebust]

We want to compare the slot_id to the highest slot number advertised by the
server.

Fixes: 3be0f80b5fe9c ("NFSv4.1: Fix up replays of interrupted requests")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/nfs4proc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e39f59b5e6d2..c5c5d6c9af25 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -780,7 +780,7 @@ static int nfs41_sequence_process(struct rpc_task *task,
 		 * The slot id we used was probably retired. Try again
 		 * using a different slot id.
 		 */
-		if (slot->seq_nr < slot->table->target_highest_slotid)
+		if (slot->slot_nr < slot->table->target_highest_slotid)
 			goto session_recover;
 		goto retry_nowait;
 	case -NFS4ERR_SEQ_MISORDERED:
-- 
2.17.1