1 files changed, 137 insertions, 28 deletions

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index defa9b4c470e..84761b5bb8e2 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -143,44 +143,49 @@ int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const n
  * Return success if the sequenceID is one more than what we last saw on
  * this slot, accounting for wraparound.  Increments the slot's sequence.
  *
- * We don't yet implement a duplicate request cache, so at this time
- * we will log replays, and process them as if we had not seen them before,
- * but we don't bump the sequence in the slot.  Not too worried about it,
+ * We don't yet implement a duplicate request cache, instead we set the
+ * back channel ca_maxresponsesize_cached to zero. This is OK for now
  * since we only currently implement idempotent callbacks anyway.
  *
  * We have a single slot backchannel at this time, so we don't bother
  * checking the used_slots bit array on the table.  The lower layer guarantees
  * a single outstanding callback request at a time.
  */
-static int
-validate_seqid(struct nfs4_slot_table *tbl, u32 slotid, u32 seqid)
+static __be32
+validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
 {
         struct nfs4_slot *slot;
 
         dprintk("%s enter. slotid %d seqid %d\n",
-                __func__, slotid, seqid);
+                __func__, args->csa_slotid, args->csa_sequenceid);
 
-        if (slotid > NFS41_BC_MAX_CALLBACKS)
+        if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS)
                 return htonl(NFS4ERR_BADSLOT);
 
-        slot = tbl->slots + slotid;
+        slot = tbl->slots + args->csa_slotid;
         dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
 
         /* Normal */
-        if (likely(seqid == slot->seq_nr + 1)) {
+        if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
                 slot->seq_nr++;
                 return htonl(NFS4_OK);
         }
 
         /* Replay */
-        if (seqid == slot->seq_nr) {
-                dprintk("%s seqid %d is a replay - no DRC available\n",
-                        __func__, seqid);
-                return htonl(NFS4_OK);
+        if (args->csa_sequenceid == slot->seq_nr) {
+                dprintk("%s seqid %d is a replay\n",
+                        __func__, args->csa_sequenceid);
+                /* Signal process_op to set this error on next op */
+                if (args->csa_cachethis == 0)
+                        return htonl(NFS4ERR_RETRY_UNCACHED_REP);
+
+                /* The ca_maxresponsesize_cached is 0 with no DRC */
+                else if (args->csa_cachethis == 1)
+                        return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
         }
 
         /* Wraparound */
-        if (seqid == 1 && (slot->seq_nr + 1) == 0) {
+        if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
                 slot->seq_nr = 1;
                 return htonl(NFS4_OK);
         }
@@ -225,27 +230,87 @@ validate_seqid(struct nfs4_slot_table *tbl, u32 slotid, u32 seqid)
         return NULL;
 }
 
-/* FIXME: referring calls should be processed */
-unsigned nfs4_callback_sequence(struct cb_sequenceargs *args,
+/*
+ * For each referring call triple, check the session's slot table for
+ * a match.  If the slot is in use and the sequence numbers match, the
+ * client is still waiting for a response to the original request.
+ */
+static bool referring_call_exists(struct nfs_client *clp,
+                                  uint32_t nrclists,
+                                  struct referring_call_list *rclists)
+{
+        bool status = 0;
+        int i, j;
+        struct nfs4_session *session;
+        struct nfs4_slot_table *tbl;
+        struct referring_call_list *rclist;
+        struct referring_call *ref;
+
+        /*
+         * XXX When client trunking is implemented, this becomes
+         * a session lookup from within the loop
+         */
+        session = clp->cl_session;
+        tbl = &session->fc_slot_table;
+
+        for (i = 0; i < nrclists; i++) {
+                rclist = &rclists[i];
+                if (memcmp(session->sess_id.data,
+                           rclist->rcl_sessionid.data,
+                           NFS4_MAX_SESSIONID_LEN) != 0)
+                        continue;
+
+                for (j = 0; j < rclist->rcl_nrefcalls; j++) {
+                        ref = &rclist->rcl_refcalls[j];
+
+                        dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
+                                "slotid %u\n", __func__,
+                                ((u32 *)&rclist->rcl_sessionid.data)[0],
+                                ((u32 *)&rclist->rcl_sessionid.data)[1],
+                                ((u32 *)&rclist->rcl_sessionid.data)[2],
+                                ((u32 *)&rclist->rcl_sessionid.data)[3],
+                                ref->rc_sequenceid, ref->rc_slotid);
+
+                        spin_lock(&tbl->slot_tbl_lock);
+                        status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
+                                  tbl->slots[ref->rc_slotid].seq_nr ==
+                                        ref->rc_sequenceid);
+                        spin_unlock(&tbl->slot_tbl_lock);
+                        if (status)
+                                goto out;
+                }
+        }
+
+out:
+        return status;
+}
+
+__be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
                                 struct cb_sequenceres *res)
 {
         struct nfs_client *clp;
-        int i, status;
-
-        for (i = 0; i < args->csa_nrclists; i++)
-                kfree(args->csa_rclists[i].rcl_refcalls);
-        kfree(args->csa_rclists);
+        int i;
+        __be32 status;
 
         status = htonl(NFS4ERR_BADSESSION);
         clp = find_client_with_session(args->csa_addr, 4, &args->csa_sessionid);
         if (clp == NULL)
                 goto out;
 
-        status = validate_seqid(&clp->cl_session->bc_slot_table,
-                                args->csa_slotid, args->csa_sequenceid);
+        status = validate_seqid(&clp->cl_session->bc_slot_table, args);
         if (status)
                 goto out_putclient;
 
+        /*
+         * Check for pending referring calls.  If a match is found, a
+         * related callback was received before the response to the original
+         * call.
+         */
+        if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
+                status = htonl(NFS4ERR_DELAY);
+                goto out_putclient;
+        }
+
         memcpy(&res->csr_sessionid, &args->csa_sessionid,
                sizeof(res->csr_sessionid));
         res->csr_sequenceid = args->csa_sequenceid;
@@ -256,15 +321,23 @@ unsigned nfs4_callback_sequence(struct cb_sequenceargs *args,
 out_putclient:
         nfs_put_client(clp);
 out:
-        dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
-        res->csr_status = status;
-        return res->csr_status;
+        for (i = 0; i < args->csa_nrclists; i++)
+                kfree(args->csa_rclists[i].rcl_refcalls);
+        kfree(args->csa_rclists);
+
+        if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP))
+                res->csr_status = 0;
+        else
+                res->csr_status = status;
+        dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
+                ntohl(status), ntohl(res->csr_status));
+        return status;
 }
 
-unsigned nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
+__be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
 {
         struct nfs_client *clp;
-        int status;
+        __be32 status;
         fmode_t flags = 0;
 
         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
@@ -289,4 +362,40 @@ out:
         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
         return status;
 }
+
+/* Reduce the fore channel's max_slots to the target value */
+__be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy)
+{
+        struct nfs_client *clp;
+        struct nfs4_slot_table *fc_tbl;
+        __be32 status;
+
+        status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
+        clp = nfs_find_client(args->crsa_addr, 4);
+        if (clp == NULL)
+                goto out;
+
+        dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
+                rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
+                args->crsa_target_max_slots);
+
+        fc_tbl = &clp->cl_session->fc_slot_table;
+
+        status = htonl(NFS4ERR_BAD_HIGH_SLOT);
+        if (args->crsa_target_max_slots > fc_tbl->max_slots ||
+            args->crsa_target_max_slots < 1)
+                goto out_putclient;
+
+        status = htonl(NFS4_OK);
+        if (args->crsa_target_max_slots == fc_tbl->max_slots)
+                goto out_putclient;
+
+        fc_tbl->target_max_slots = args->crsa_target_max_slots;
+        nfs41_handle_recall_slot(clp);
+out_putclient:
+        nfs_put_client(clp);    /* balance nfs_find_client */
+out:
+        dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+        return status;
+}
 #endif /* CONFIG_NFS_V4_1 */