1/*
  2 * fs/nfs/nfs4session.h
  3 *
  4 * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
  5 *
  6 */
  7#ifndef __LINUX_FS_NFS_NFS4SESSION_H
  8#define __LINUX_FS_NFS_NFS4SESSION_H
  9
 10/* maximum number of slots to use */
 11#define NFS4_DEF_SLOT_TABLE_SIZE (64U)
 12#define NFS4_DEF_CB_SLOT_TABLE_SIZE (1U)
 13#define NFS4_MAX_SLOT_TABLE (1024U)
 14#define NFS4_NO_SLOT ((u32)-1)
 15
 16#if IS_ENABLED(CONFIG_NFS_V4)
 17
 18/* Sessions slot seqid */
 19struct nfs4_slot {
 20	struct nfs4_slot_table	*table;
 21	struct nfs4_slot	*next;
 22	unsigned long		generation;
 23	u32			slot_nr;
 24	u32		 	seq_nr;
 25	unsigned int		interrupted : 1,
 26				privileged : 1,
 27				seq_done : 1;
 28};
 29
 30/* Sessions */
 31enum nfs4_slot_tbl_state {
 32	NFS4_SLOT_TBL_DRAINING,
 33};
 34
 35#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
 36struct nfs4_slot_table {
 37	struct nfs4_session *session;		/* Parent session */
 38	struct nfs4_slot *slots;		/* seqid per slot */
 39	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
 40	spinlock_t	slot_tbl_lock;
 41	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
 42	wait_queue_head_t	slot_waitq;	/* Completion wait on slot */
 43	u32		max_slots;		/* # slots in table */
 44	u32		max_slotid;		/* Max allowed slotid value */
 45	u32		highest_used_slotid;	/* sent to server on each SEQ.
 46						 * op for dynamic resizing */
 47	u32		target_highest_slotid;	/* Server max_slot target */
 48	u32		server_highest_slotid;	/* Server highest slotid */
 49	s32		d_target_highest_slotid; /* Derivative */
 50	s32		d2_target_highest_slotid; /* 2nd derivative */
 51	unsigned long	generation;		/* Generation counter for
 52						   target_highest_slotid */
 53	struct completion complete;
 54	unsigned long	slot_tbl_state;
 55};
 56
 57/*
 58 * Session related parameters
 59 */
 60struct nfs4_session {
 61	struct nfs4_sessionid		sess_id;
 62	u32				flags;
 63	unsigned long			session_state;
 64	u32				hash_alg;
 65	u32				ssv_len;
 66
 67	/* The fore and back channel */
 68	struct nfs4_channel_attrs	fc_attrs;
 69	struct nfs4_slot_table		fc_slot_table;
 70	struct nfs4_channel_attrs	bc_attrs;
 71	struct nfs4_slot_table		bc_slot_table;
 72	struct nfs_client		*clp;
 73};
 74
 75enum nfs4_session_state {
 76	NFS4_SESSION_INITING,
 77	NFS4_SESSION_ESTABLISHED,
 78};
 79
 80extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
 81		unsigned int max_reqs, const char *queue);
 82extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
 83extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
 84extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
 85extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
 86		u32 slotid, u32 seq_nr,
 87		unsigned long timeout);
 88extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
 89extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
 90extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
 91bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
 92		struct nfs4_slot *slot);
 93void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
 94
 95static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
 96{
 97	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 98}
 99
100static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
101		u32 slotid)
102{
103	return !!test_bit(slotid, tbl->used_slots);
104}
105
106#if defined(CONFIG_NFS_V4_1)
107extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
108		u32 target_highest_slotid);
109extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
110		struct nfs4_slot *slot,
111		struct nfs4_sequence_res *res);
112
113extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
114
115extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
116extern void nfs4_destroy_session(struct nfs4_session *session);
117extern int nfs4_init_session(struct nfs_client *clp);
118extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
119
120/*
121 * Determine if sessions are in use.
122 */
123static inline int nfs4_has_session(const struct nfs_client *clp)
124{
125	if (clp->cl_session)
126		return 1;
127	return 0;
128}
129
130static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
131{
132	if (nfs4_has_session(clp))
133		return (clp->cl_session->flags & SESSION4_PERSIST);
134	return 0;
135}
136
137static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
138		const struct nfs4_sessionid *src)
139{
140	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
141}
142
143#ifdef CONFIG_CRC32
144/*
145 * nfs_session_id_hash - calculate the crc32 hash for the session id
146 * @session - pointer to session
147 */
148#define nfs_session_id_hash(sess_id) \
149	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
150#else
151#define nfs_session_id_hash(session) (0)
152#endif
153#else /* defined(CONFIG_NFS_V4_1) */
154
155static inline int nfs4_init_session(struct nfs_client *clp)
156{
157	return 0;
158}
159
160/*
161 * Determine if sessions are in use.
162 */
163static inline int nfs4_has_session(const struct nfs_client *clp)
164{
165	return 0;
166}
167
168static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
169{
170	return 0;
171}
172
173#endif /* defined(CONFIG_NFS_V4_1) */
174#endif /* IS_ENABLED(CONFIG_NFS_V4) */
175#endif /* __LINUX_FS_NFS_NFS4SESSION_H */