1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * fs/nfs/nfs4session.h
4 *
5 * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
6 *
7 */
8#ifndef __LINUX_FS_NFS_NFS4SESSION_H
9#define __LINUX_FS_NFS_NFS4SESSION_H
10
11/* maximum number of slots to use */
12#define NFS4_DEF_SLOT_TABLE_SIZE (64U)
13#define NFS4_DEF_CB_SLOT_TABLE_SIZE (16U)
14#define NFS4_MAX_SLOT_TABLE (1024U)
15#define NFS4_MAX_SLOTID (NFS4_MAX_SLOT_TABLE - 1U)
16#define NFS4_NO_SLOT ((u32)-1)
17
18#if IS_ENABLED(CONFIG_NFS_V4)
19
20/* Sessions slot seqid */
21struct nfs4_slot {
22	struct nfs4_slot_table	*table;
23	struct nfs4_slot	*next;
24	unsigned long		generation;
25	u32			slot_nr;
26	u32		 	seq_nr;
27	u32		 	seq_nr_last_acked;
28	u32		 	seq_nr_highest_sent;
29	unsigned int		privileged : 1,
30				seq_done : 1;
31};
32
33/* Sessions */
34enum nfs4_slot_tbl_state {
35	NFS4_SLOT_TBL_DRAINING,
36};
37
38#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, BITS_PER_LONG)
39struct nfs4_slot_table {
40	struct nfs4_session *session;		/* Parent session */
41	struct nfs4_slot *slots;		/* seqid per slot */
42	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
43	spinlock_t	slot_tbl_lock;
44	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
45	wait_queue_head_t	slot_waitq;	/* Completion wait on slot */
46	u32		max_slots;		/* # slots in table */
47	u32		max_slotid;		/* Max allowed slotid value */
48	u32		highest_used_slotid;	/* sent to server on each SEQ.
49						 * op for dynamic resizing */
50	u32		target_highest_slotid;	/* Server max_slot target */
51	u32		server_highest_slotid;	/* Server highest slotid */
52	s32		d_target_highest_slotid; /* Derivative */
53	s32		d2_target_highest_slotid; /* 2nd derivative */
54	unsigned long	generation;		/* Generation counter for
55						   target_highest_slotid */
56	struct completion complete;
57	unsigned long	slot_tbl_state;
58};
59
60/*
61 * Session related parameters
62 */
63struct nfs4_session {
64	struct nfs4_sessionid		sess_id;
65	u32				flags;
66	unsigned long			session_state;
67	u32				hash_alg;
68	u32				ssv_len;
69
70	/* The fore and back channel */
71	struct nfs4_channel_attrs	fc_attrs;
72	struct nfs4_slot_table		fc_slot_table;
73	struct nfs4_channel_attrs	bc_attrs;
74	struct nfs4_slot_table		bc_slot_table;
75	struct nfs_client		*clp;
76};
77
78enum nfs4_session_state {
79	NFS4_SESSION_INITING,
80	NFS4_SESSION_ESTABLISHED,
81};
82
83extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
84		unsigned int max_reqs, const char *queue);
85extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
86extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
87extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
88extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
89		u32 slotid, u32 seq_nr,
90		unsigned long timeout);
91extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
92extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
93extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
94bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
95		struct nfs4_slot *slot);
96void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
97
98static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
99{
100	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
101}
102
103static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
104		u32 slotid)
105{
106	return !!test_bit(slotid, tbl->used_slots);
107}
108
109static inline struct nfs4_session *nfs4_get_session(const struct nfs_client *clp)
110{
111	return clp->cl_session;
112}
113
114#if defined(CONFIG_NFS_V4_1)
115extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
116		u32 target_highest_slotid);
117extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
118		struct nfs4_slot *slot,
119		struct nfs4_sequence_res *res);
120
121extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
122
123extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
124extern void nfs4_destroy_session(struct nfs4_session *session);
125extern int nfs4_init_session(struct nfs_client *clp);
126extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
127
128/*
129 * Determine if sessions are in use.
130 */
131static inline int nfs4_has_session(const struct nfs_client *clp)
132{
133	if (clp->cl_session)
134		return 1;
135	return 0;
136}
137
138static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
139{
140	if (nfs4_has_session(clp))
141		return (clp->cl_session->flags & SESSION4_PERSIST);
142	return 0;
143}
144
145static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
146		const struct nfs4_sessionid *src)
147{
148	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
149}
150
151#ifdef CONFIG_CRC32
152/*
153 * nfs_session_id_hash - calculate the crc32 hash for the session id
154 * @session - pointer to session
155 */
156#define nfs_session_id_hash(sess_id) \
157	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
158#else
159#define nfs_session_id_hash(session) (0)
160#endif
161#else /* defined(CONFIG_NFS_V4_1) */
162
163static inline int nfs4_init_session(struct nfs_client *clp)
164{
165	return 0;
166}
167
168/*
169 * Determine if sessions are in use.
170 */
171static inline int nfs4_has_session(const struct nfs_client *clp)
172{
173	return 0;
174}
175
176static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
177{
178	return 0;
179}
180
181#define nfs_session_id_hash(session) (0)
182
183#endif /* defined(CONFIG_NFS_V4_1) */
184#endif /* IS_ENABLED(CONFIG_NFS_V4) */
185#endif /* __LINUX_FS_NFS_NFS4SESSION_H */
186