+/* maximum number of slots to use */
+#define NFS4_DEF_SLOT_TABLE_SIZE (16U)
+#define NFS4_MAX_SLOT_TABLE (256U)
+#define NFS4_NO_SLOT ((u32)-1)
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+
+/* Sessions slot seqid */
+struct nfs4_slot {
+ struct nfs4_slot_table *table;
+ struct nfs4_slot *next;
+ unsigned long generation;
+ unsigned long renewal_time;
+ u32 slot_nr;
+ u32 seq_nr;
+};
+
+/* Sessions */
+#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
+struct nfs4_slot_table {
+ struct nfs4_session *session; /* Parent session */
+ struct nfs4_slot *slots; /* seqid per slot */
+ unsigned long used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
+ spinlock_t slot_tbl_lock;
+ struct rpc_wait_queue slot_tbl_waitq; /* allocators may wait here */
+ u32 max_slots; /* # slots in table */
+ u32 max_slotid; /* Max allowed slotid value */
+ u32 highest_used_slotid; /* sent to server on each SEQ.
+ * op for dynamic resizing */
+ u32 target_highest_slotid; /* Server max_slot target */
+ u32 server_highest_slotid; /* Server highest slotid */
+ unsigned long generation; /* Generation counter for
+ target_highest_slotid */
+ struct completion complete;
+};
+
+/*
+ * Session related parameters
+ */
+struct nfs4_session {
+ struct nfs4_sessionid sess_id;
+ u32 flags;
+ unsigned long session_state;
+ u32 hash_alg;
+ u32 ssv_len;
+
+ /* The fore and back channel */
+ struct nfs4_channel_attrs fc_attrs;
+ struct nfs4_slot_table fc_slot_table;
+ struct nfs4_channel_attrs bc_attrs;
+ struct nfs4_slot_table bc_slot_table;
+ struct nfs_client *clp;
+ /* Create session arguments */
+ unsigned int fc_target_max_rqst_sz;
+ unsigned int fc_target_max_resp_sz;
+};
+
+enum nfs4_session_state {
+ NFS4_SESSION_INITING,
+ NFS4_SESSION_DRAINING,
+};
+