xref: /openbmc/linux/fs/nfs/nfs4session.h (revision 4e1a33b1)
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 */
19 struct 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 */
31 enum 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))
36 struct 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  */
60 struct 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 
75 enum nfs4_session_state {
76 	NFS4_SESSION_INITING,
77 	NFS4_SESSION_ESTABLISHED,
78 };
79 
80 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
81 		unsigned int max_reqs, const char *queue);
82 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
83 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
84 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
85 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
86 		u32 slotid, u32 seq_nr,
87 		unsigned long timeout);
88 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
89 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
90 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
91 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
92 		struct nfs4_slot *slot);
93 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
94 
95 static 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 
100 static 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)
107 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
108 		u32 target_highest_slotid);
109 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
110 		struct nfs4_slot *slot,
111 		struct nfs4_sequence_res *res);
112 
113 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
114 
115 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
116 extern void nfs4_destroy_session(struct nfs4_session *session);
117 extern int nfs4_init_session(struct nfs_client *clp);
118 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
119 
120 /*
121  * Determine if sessions are in use.
122  */
123 static inline int nfs4_has_session(const struct nfs_client *clp)
124 {
125 	if (clp->cl_session)
126 		return 1;
127 	return 0;
128 }
129 
130 static 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 
137 static 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 
155 static inline int nfs4_init_session(struct nfs_client *clp)
156 {
157 	return 0;
158 }
159 
160 /*
161  * Determine if sessions are in use.
162  */
163 static inline int nfs4_has_session(const struct nfs_client *clp)
164 {
165 	return 0;
166 }
167 
168 static 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 */
176