xref: /openbmc/linux/fs/nfs/nfs4session.h (revision 089a49b6)
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_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 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
76 		unsigned int max_reqs, const char *queue);
77 extern void nfs4_release_slot_table(struct nfs4_slot_table *tbl);
78 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
79 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
80 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
81 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
82 		struct nfs4_slot *slot);
83 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
84 
85 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
86 {
87 	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
88 }
89 
90 #if defined(CONFIG_NFS_V4_1)
91 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
92 		u32 target_highest_slotid);
93 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
94 		struct nfs4_slot *slot,
95 		struct nfs4_sequence_res *res);
96 
97 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
98 
99 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
100 extern void nfs4_destroy_session(struct nfs4_session *session);
101 extern int nfs4_init_session(struct nfs_client *clp);
102 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
103 
104 /*
105  * Determine if sessions are in use.
106  */
107 static inline int nfs4_has_session(const struct nfs_client *clp)
108 {
109 	if (clp->cl_session)
110 		return 1;
111 	return 0;
112 }
113 
114 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
115 {
116 	if (nfs4_has_session(clp))
117 		return (clp->cl_session->flags & SESSION4_PERSIST);
118 	return 0;
119 }
120 
121 #ifdef CONFIG_CRC32
122 /*
123  * nfs_session_id_hash - calculate the crc32 hash for the session id
124  * @session - pointer to session
125  */
126 #define nfs_session_id_hash(sess_id) \
127 	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
128 #else
129 #define nfs_session_id_hash(session) (0)
130 #endif
131 #else /* defined(CONFIG_NFS_V4_1) */
132 
133 static inline int nfs4_init_session(struct nfs_client *clp)
134 {
135 	return 0;
136 }
137 
138 /*
139  * Determine if sessions are in use.
140  */
141 static inline int nfs4_has_session(const struct nfs_client *clp)
142 {
143 	return 0;
144 }
145 
146 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
147 {
148 	return 0;
149 }
150 
151 #endif /* defined(CONFIG_NFS_V4_1) */
152 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
153 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */
154