NFSv4.1: Reset the sequence number for slots that have been deallocated

When the server tells us that it is dynamically resizing the session
replay cache, we should reset the sequence number for those slots
that have been deallocated.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 20 insertions, 2 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d91abaa522e8..52435ec44193 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -498,6 +498,22 @@ static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl,
         tbl->generation++;
 }
 
+static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl,
+                u32 highest_slotid)
+{
+        unsigned int max_slotid, i;
+
+        if (tbl->server_highest_slotid == highest_slotid)
+                return;
+        if (tbl->highest_used_slotid > highest_slotid)
+                return;
+        max_slotid = min(tbl->max_slots - 1, highest_slotid);
+        /* Reset the seq_nr for deallocated slots */
+        for (i = tbl->server_highest_slotid + 1; i <= max_slotid; i++)
+                tbl->slots[i].seq_nr = 1;
+        tbl->server_highest_slotid = highest_slotid;
+}
+
 static void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
                 struct nfs4_slot *slot,
                 struct nfs4_sequence_res *res)
@@ -505,6 +521,7 @@ static void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
         spin_lock(&tbl->slot_tbl_lock);
         if (tbl->generation != slot->generation)
                 goto out;
+        nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid);
         nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid);
 out:
         spin_unlock(&tbl->slot_tbl_lock);
@@ -5718,6 +5735,7 @@ static void nfs4_add_and_init_slots(struct nfs4_slot_table *tbl,
         }
         tbl->highest_used_slotid = NFS4_NO_SLOT;
         tbl->target_highest_slotid = max_slots - 1;
+        tbl->server_highest_slotid = max_slots - 1;
         for (i = 0; i < tbl->max_slots; i++)
                 tbl->slots[i].seq_nr = ivalue;
         spin_unlock(&tbl->slot_tbl_lock);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 05d34f1fcc19..a67040f51597 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5550,8 +5550,8 @@ static int decode_sequence(struct xdr_stream *xdr,
                 dprintk("%s Invalid slot id\n", __func__);
                 goto out_err;
         }
-        /* highest slot id - currently not processed */
-        dummy = be32_to_cpup(p++);
+        /* highest slot id */
+        res->sr_highest_slotid = be32_to_cpup(p++);
         /* target highest slot id */
         res->sr_target_highest_slotid = be32_to_cpup(p++);
         /* result flags */