xref: /openbmc/linux/fs/nfs/nfs4session.h (revision f96f8cc4)
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 */
21 struct 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 */
34 enum 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)
39 struct 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  */
63 struct 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 
78 enum nfs4_session_state {
79 	NFS4_SESSION_INITING,
80 	NFS4_SESSION_ESTABLISHED,
81 };
82 
83 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
84 		unsigned int max_reqs, const char *queue);
85 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
86 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
87 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
88 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
89 		u32 slotid, u32 seq_nr,
90 		unsigned long timeout);
91 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
92 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
93 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
94 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
95 		struct nfs4_slot *slot);
96 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
97 
nfs4_slot_tbl_draining(struct nfs4_slot_table * tbl)98 static 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 
nfs4_test_locked_slot(const struct nfs4_slot_table * tbl,u32 slotid)103 static 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 
nfs4_get_session(const struct nfs_client * clp)109 static 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)
115 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
116 		u32 target_highest_slotid);
117 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
118 		struct nfs4_slot *slot,
119 		struct nfs4_sequence_res *res);
120 
121 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
122 
123 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
124 extern void nfs4_destroy_session(struct nfs4_session *session);
125 extern int nfs4_init_session(struct nfs_client *clp);
126 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
127 
128 /*
129  * Determine if sessions are in use.
130  */
nfs4_has_session(const struct nfs_client * clp)131 static inline int nfs4_has_session(const struct nfs_client *clp)
132 {
133 	if (clp->cl_session)
134 		return 1;
135 	return 0;
136 }
137 
nfs4_has_persistent_session(const struct nfs_client * clp)138 static 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 
nfs4_copy_sessionid(struct nfs4_sessionid * dst,const struct nfs4_sessionid * src)145 static 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 
nfs4_init_session(struct nfs_client * clp)163 static inline int nfs4_init_session(struct nfs_client *clp)
164 {
165 	return 0;
166 }
167 
168 /*
169  * Determine if sessions are in use.
170  */
nfs4_has_session(const struct nfs_client * clp)171 static inline int nfs4_has_session(const struct nfs_client *clp)
172 {
173 	return 0;
174 }
175 
nfs4_has_persistent_session(const struct nfs_client * clp)176 static 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