xref: /openbmc/linux/fs/nfs/nfs4session.h (revision 78700c0a)
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 	NFS4_SESSION_ESTABLISHED,
74 };
75 
76 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
77 		unsigned int max_reqs, const char *queue);
78 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
79 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
80 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
81 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
82 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
83 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
84 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
85 		struct nfs4_slot *slot);
86 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
87 
88 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
89 {
90 	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
91 }
92 
93 static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
94 		u32 slotid)
95 {
96 	return !!test_bit(slotid, tbl->used_slots);
97 }
98 
99 #if defined(CONFIG_NFS_V4_1)
100 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
101 		u32 target_highest_slotid);
102 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
103 		struct nfs4_slot *slot,
104 		struct nfs4_sequence_res *res);
105 
106 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
107 
108 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
109 extern void nfs4_destroy_session(struct nfs4_session *session);
110 extern int nfs4_init_session(struct nfs_client *clp);
111 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
112 
113 /*
114  * Determine if sessions are in use.
115  */
116 static inline int nfs4_has_session(const struct nfs_client *clp)
117 {
118 	if (clp->cl_session)
119 		return 1;
120 	return 0;
121 }
122 
123 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
124 {
125 	if (nfs4_has_session(clp))
126 		return (clp->cl_session->flags & SESSION4_PERSIST);
127 	return 0;
128 }
129 
130 static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
131 		const struct nfs4_sessionid *src)
132 {
133 	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
134 }
135 
136 #ifdef CONFIG_CRC32
137 /*
138  * nfs_session_id_hash - calculate the crc32 hash for the session id
139  * @session - pointer to session
140  */
141 #define nfs_session_id_hash(sess_id) \
142 	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
143 #else
144 #define nfs_session_id_hash(session) (0)
145 #endif
146 #else /* defined(CONFIG_NFS_V4_1) */
147 
148 static inline int nfs4_init_session(struct nfs_client *clp)
149 {
150 	return 0;
151 }
152 
153 /*
154  * Determine if sessions are in use.
155  */
156 static inline int nfs4_has_session(const struct nfs_client *clp)
157 {
158 	return 0;
159 }
160 
161 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
162 {
163 	return 0;
164 }
165 
166 #endif /* defined(CONFIG_NFS_V4_1) */
167 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
168 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */
169