xref: /openbmc/linux/fs/nfs/nfs4session.h (revision bc5aa3a0)
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 				seq_done : 1;
26 };
27 
28 /* Sessions */
29 enum nfs4_slot_tbl_state {
30 	NFS4_SLOT_TBL_DRAINING,
31 };
32 
33 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
34 struct nfs4_slot_table {
35 	struct nfs4_session *session;		/* Parent session */
36 	struct nfs4_slot *slots;		/* seqid per slot */
37 	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
38 	spinlock_t	slot_tbl_lock;
39 	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
40 	wait_queue_head_t	slot_waitq;	/* Completion wait on slot */
41 	u32		max_slots;		/* # slots in table */
42 	u32		max_slotid;		/* Max allowed slotid value */
43 	u32		highest_used_slotid;	/* sent to server on each SEQ.
44 						 * op for dynamic resizing */
45 	u32		target_highest_slotid;	/* Server max_slot target */
46 	u32		server_highest_slotid;	/* Server highest slotid */
47 	s32		d_target_highest_slotid; /* Derivative */
48 	s32		d2_target_highest_slotid; /* 2nd derivative */
49 	unsigned long	generation;		/* Generation counter for
50 						   target_highest_slotid */
51 	struct completion complete;
52 	unsigned long	slot_tbl_state;
53 };
54 
55 /*
56  * Session related parameters
57  */
58 struct nfs4_session {
59 	struct nfs4_sessionid		sess_id;
60 	u32				flags;
61 	unsigned long			session_state;
62 	u32				hash_alg;
63 	u32				ssv_len;
64 
65 	/* The fore and back channel */
66 	struct nfs4_channel_attrs	fc_attrs;
67 	struct nfs4_slot_table		fc_slot_table;
68 	struct nfs4_channel_attrs	bc_attrs;
69 	struct nfs4_slot_table		bc_slot_table;
70 	struct nfs_client		*clp;
71 };
72 
73 enum nfs4_session_state {
74 	NFS4_SESSION_INITING,
75 	NFS4_SESSION_ESTABLISHED,
76 };
77 
78 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
79 		unsigned int max_reqs, const char *queue);
80 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
81 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
82 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
83 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
84 		u32 slotid, u32 seq_nr,
85 		unsigned long timeout);
86 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
87 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
88 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
89 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
90 		struct nfs4_slot *slot);
91 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
92 
93 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
94 {
95 	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
96 }
97 
98 static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
99 		u32 slotid)
100 {
101 	return !!test_bit(slotid, tbl->used_slots);
102 }
103 
104 #if defined(CONFIG_NFS_V4_1)
105 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
106 		u32 target_highest_slotid);
107 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
108 		struct nfs4_slot *slot,
109 		struct nfs4_sequence_res *res);
110 
111 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
112 
113 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
114 extern void nfs4_destroy_session(struct nfs4_session *session);
115 extern int nfs4_init_session(struct nfs_client *clp);
116 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
117 
118 /*
119  * Determine if sessions are in use.
120  */
121 static inline int nfs4_has_session(const struct nfs_client *clp)
122 {
123 	if (clp->cl_session)
124 		return 1;
125 	return 0;
126 }
127 
128 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
129 {
130 	if (nfs4_has_session(clp))
131 		return (clp->cl_session->flags & SESSION4_PERSIST);
132 	return 0;
133 }
134 
135 static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
136 		const struct nfs4_sessionid *src)
137 {
138 	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
139 }
140 
141 #ifdef CONFIG_CRC32
142 /*
143  * nfs_session_id_hash - calculate the crc32 hash for the session id
144  * @session - pointer to session
145  */
146 #define nfs_session_id_hash(sess_id) \
147 	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
148 #else
149 #define nfs_session_id_hash(session) (0)
150 #endif
151 #else /* defined(CONFIG_NFS_V4_1) */
152 
153 static inline int nfs4_init_session(struct nfs_client *clp)
154 {
155 	return 0;
156 }
157 
158 /*
159  * Determine if sessions are in use.
160  */
161 static inline int nfs4_has_session(const struct nfs_client *clp)
162 {
163 	return 0;
164 }
165 
166 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
167 {
168 	return 0;
169 }
170 
171 #endif /* defined(CONFIG_NFS_V4_1) */
172 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
173 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */
174