xref: /openbmc/linux/fs/nfs/nfs4session.h (revision d0e22329)
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 (1U)
14 #define NFS4_MAX_SLOT_TABLE (1024U)
15 #define NFS4_NO_SLOT ((u32)-1)
16 
17 #if IS_ENABLED(CONFIG_NFS_V4)
18 
19 /* Sessions slot seqid */
20 struct nfs4_slot {
21 	struct nfs4_slot_table	*table;
22 	struct nfs4_slot	*next;
23 	unsigned long		generation;
24 	u32			slot_nr;
25 	u32		 	seq_nr;
26 	unsigned int		interrupted : 1,
27 				privileged : 1,
28 				seq_done : 1;
29 };
30 
31 /* Sessions */
32 enum nfs4_slot_tbl_state {
33 	NFS4_SLOT_TBL_DRAINING,
34 };
35 
36 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
37 struct nfs4_slot_table {
38 	struct nfs4_session *session;		/* Parent session */
39 	struct nfs4_slot *slots;		/* seqid per slot */
40 	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
41 	spinlock_t	slot_tbl_lock;
42 	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
43 	wait_queue_head_t	slot_waitq;	/* Completion wait on slot */
44 	u32		max_slots;		/* # slots in table */
45 	u32		max_slotid;		/* Max allowed slotid value */
46 	u32		highest_used_slotid;	/* sent to server on each SEQ.
47 						 * op for dynamic resizing */
48 	u32		target_highest_slotid;	/* Server max_slot target */
49 	u32		server_highest_slotid;	/* Server highest slotid */
50 	s32		d_target_highest_slotid; /* Derivative */
51 	s32		d2_target_highest_slotid; /* 2nd derivative */
52 	unsigned long	generation;		/* Generation counter for
53 						   target_highest_slotid */
54 	struct completion complete;
55 	unsigned long	slot_tbl_state;
56 };
57 
58 /*
59  * Session related parameters
60  */
61 struct nfs4_session {
62 	struct nfs4_sessionid		sess_id;
63 	u32				flags;
64 	unsigned long			session_state;
65 	u32				hash_alg;
66 	u32				ssv_len;
67 
68 	/* The fore and back channel */
69 	struct nfs4_channel_attrs	fc_attrs;
70 	struct nfs4_slot_table		fc_slot_table;
71 	struct nfs4_channel_attrs	bc_attrs;
72 	struct nfs4_slot_table		bc_slot_table;
73 	struct nfs_client		*clp;
74 };
75 
76 enum nfs4_session_state {
77 	NFS4_SESSION_INITING,
78 	NFS4_SESSION_ESTABLISHED,
79 };
80 
81 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
82 		unsigned int max_reqs, const char *queue);
83 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
84 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
85 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
86 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
87 		u32 slotid, u32 seq_nr,
88 		unsigned long timeout);
89 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
90 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
91 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
92 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
93 		struct nfs4_slot *slot);
94 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
95 
96 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
97 {
98 	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
99 }
100 
101 static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
102 		u32 slotid)
103 {
104 	return !!test_bit(slotid, tbl->used_slots);
105 }
106 
107 static inline struct nfs4_session *nfs4_get_session(const struct nfs_client *clp)
108 {
109 	return clp->cl_session;
110 }
111 
112 #if defined(CONFIG_NFS_V4_1)
113 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
114 		u32 target_highest_slotid);
115 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
116 		struct nfs4_slot *slot,
117 		struct nfs4_sequence_res *res);
118 
119 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
120 
121 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
122 extern void nfs4_destroy_session(struct nfs4_session *session);
123 extern int nfs4_init_session(struct nfs_client *clp);
124 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
125 
126 /*
127  * Determine if sessions are in use.
128  */
129 static inline int nfs4_has_session(const struct nfs_client *clp)
130 {
131 	if (clp->cl_session)
132 		return 1;
133 	return 0;
134 }
135 
136 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
137 {
138 	if (nfs4_has_session(clp))
139 		return (clp->cl_session->flags & SESSION4_PERSIST);
140 	return 0;
141 }
142 
143 static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
144 		const struct nfs4_sessionid *src)
145 {
146 	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
147 }
148 
149 #ifdef CONFIG_CRC32
150 /*
151  * nfs_session_id_hash - calculate the crc32 hash for the session id
152  * @session - pointer to session
153  */
154 #define nfs_session_id_hash(sess_id) \
155 	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
156 #else
157 #define nfs_session_id_hash(session) (0)
158 #endif
159 #else /* defined(CONFIG_NFS_V4_1) */
160 
161 static inline int nfs4_init_session(struct nfs_client *clp)
162 {
163 	return 0;
164 }
165 
166 /*
167  * Determine if sessions are in use.
168  */
169 static inline int nfs4_has_session(const struct nfs_client *clp)
170 {
171 	return 0;
172 }
173 
174 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
175 {
176 	return 0;
177 }
178 
179 #define nfs_session_id_hash(session) (0)
180 
181 #endif /* defined(CONFIG_NFS_V4_1) */
182 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
183 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */
184