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/*
152 * nfs_session_id_hash - calculate the crc32 hash for the session id
153 * @session - pointer to session
154 */
155#define nfs_session_id_hash(sess_id) \
156 (~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
157#else /* defined(CONFIG_NFS_V4_1) */
158
159static inline int nfs4_init_session(struct nfs_client *clp)
160{
161 return 0;
162}
163
164/*
165 * Determine if sessions are in use.
166 */
167static inline int nfs4_has_session(const struct nfs_client *clp)
168{
169 return 0;
170}
171
172static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
173{
174 return 0;
175}
176
177#define nfs_session_id_hash(session) (0)
178
179#endif /* defined(CONFIG_NFS_V4_1) */
180#endif /* IS_ENABLED(CONFIG_NFS_V4) */
181#endif /* __LINUX_FS_NFS_NFS4SESSION_H */
182