xref: /openbmc/linux/fs/nfs/nfs4session.h (revision 5104d265)
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 (16U)
12 #define NFS4_MAX_SLOT_TABLE (1024U)
13 #define NFS4_NO_SLOT ((u32)-1)
14 
15 #if IS_ENABLED(CONFIG_NFS_V4)
16 
17 /* Sessions slot seqid */
18 struct nfs4_slot {
19 	struct nfs4_slot_table	*table;
20 	struct nfs4_slot	*next;
21 	unsigned long		generation;
22 	u32			slot_nr;
23 	u32		 	seq_nr;
24 	unsigned int		interrupted : 1;
25 };
26 
27 /* Sessions */
28 enum nfs4_slot_tbl_state {
29 	NFS4_SLOT_TBL_DRAINING,
30 };
31 
32 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
33 struct nfs4_slot_table {
34 	struct nfs4_session *session;		/* Parent session */
35 	struct nfs4_slot *slots;		/* seqid per slot */
36 	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
37 	spinlock_t	slot_tbl_lock;
38 	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
39 	u32		max_slots;		/* # slots in table */
40 	u32		max_slotid;		/* Max allowed slotid value */
41 	u32		highest_used_slotid;	/* sent to server on each SEQ.
42 						 * op for dynamic resizing */
43 	u32		target_highest_slotid;	/* Server max_slot target */
44 	u32		server_highest_slotid;	/* Server highest slotid */
45 	s32		d_target_highest_slotid; /* Derivative */
46 	s32		d2_target_highest_slotid; /* 2nd derivative */
47 	unsigned long	generation;		/* Generation counter for
48 						   target_highest_slotid */
49 	struct completion complete;
50 	unsigned long	slot_tbl_state;
51 };
52 
53 /*
54  * Session related parameters
55  */
56 struct nfs4_session {
57 	struct nfs4_sessionid		sess_id;
58 	u32				flags;
59 	unsigned long			session_state;
60 	u32				hash_alg;
61 	u32				ssv_len;
62 
63 	/* The fore and back channel */
64 	struct nfs4_channel_attrs	fc_attrs;
65 	struct nfs4_slot_table		fc_slot_table;
66 	struct nfs4_channel_attrs	bc_attrs;
67 	struct nfs4_slot_table		bc_slot_table;
68 	struct nfs_client		*clp;
69 };
70 
71 enum nfs4_session_state {
72 	NFS4_SESSION_INITING,
73 };
74 
75 #if defined(CONFIG_NFS_V4_1)
76 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
77 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
78 
79 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
80 		u32 target_highest_slotid);
81 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
82 		struct nfs4_slot *slot,
83 		struct nfs4_sequence_res *res);
84 
85 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
86 
87 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
88 extern void nfs4_destroy_session(struct nfs4_session *session);
89 extern int nfs4_init_session(struct nfs_client *clp);
90 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
91 
92 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
93 
94 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
95 {
96 	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
97 }
98 
99 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
100 		struct nfs4_slot *slot);
101 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
102 
103 /*
104  * Determine if sessions are in use.
105  */
106 static inline int nfs4_has_session(const struct nfs_client *clp)
107 {
108 	if (clp->cl_session)
109 		return 1;
110 	return 0;
111 }
112 
113 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
114 {
115 	if (nfs4_has_session(clp))
116 		return (clp->cl_session->flags & SESSION4_PERSIST);
117 	return 0;
118 }
119 
120 #else /* defined(CONFIG_NFS_V4_1) */
121 
122 static inline int nfs4_init_session(struct nfs_client *clp)
123 {
124 	return 0;
125 }
126 
127 /*
128  * Determine if sessions are in use.
129  */
130 static inline int nfs4_has_session(const struct nfs_client *clp)
131 {
132 	return 0;
133 }
134 
135 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
136 {
137 	return 0;
138 }
139 
140 #endif /* defined(CONFIG_NFS_V4_1) */
141 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
142 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */
143