xref: /linux/drivers/block/drbd/drbd_state.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 #ifndef DRBD_STATE_H
2 #define DRBD_STATE_H
3 
4 struct drbd_device;
5 struct drbd_connection;
6 
7 /**
8  * DOC: DRBD State macros
9  *
10  * These macros are used to express state changes in easily readable form.
11  *
12  * The NS macros expand to a mask and a value, that can be bit ored onto the
13  * current state as soon as the spinlock (req_lock) was taken.
14  *
15  * The _NS macros are used for state functions that get called with the
16  * spinlock. These macros expand directly to the new state value.
17  *
18  * Besides the basic forms NS() and _NS() additional _?NS[23] are defined
19  * to express state changes that affect more than one aspect of the state.
20  *
21  * E.g. NS2(conn, C_CONNECTED, peer, R_SECONDARY)
22  * Means that the network connection was established and that the peer
23  * is in secondary role.
24  */
25 #define role_MASK R_MASK
26 #define peer_MASK R_MASK
27 #define disk_MASK D_MASK
28 #define pdsk_MASK D_MASK
29 #define conn_MASK C_MASK
30 #define susp_MASK 1
31 #define user_isp_MASK 1
32 #define aftr_isp_MASK 1
33 #define susp_nod_MASK 1
34 #define susp_fen_MASK 1
35 
36 #define NS(T, S) \
37 	({ union drbd_state mask; mask.i = 0; mask.T = T##_MASK; mask; }), \
38 	({ union drbd_state val; val.i = 0; val.T = (S); val; })
39 #define NS2(T1, S1, T2, S2) \
40 	({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \
41 	  mask.T2 = T2##_MASK; mask; }), \
42 	({ union drbd_state val; val.i = 0; val.T1 = (S1); \
43 	  val.T2 = (S2); val; })
44 #define NS3(T1, S1, T2, S2, T3, S3) \
45 	({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \
46 	  mask.T2 = T2##_MASK; mask.T3 = T3##_MASK; mask; }), \
47 	({ union drbd_state val;  val.i = 0; val.T1 = (S1); \
48 	  val.T2 = (S2); val.T3 = (S3); val; })
49 
50 #define _NS(D, T, S) \
51 	D, ({ union drbd_state __ns; __ns = drbd_read_state(D); __ns.T = (S); __ns; })
52 #define _NS2(D, T1, S1, T2, S2) \
53 	D, ({ union drbd_state __ns; __ns = drbd_read_state(D); __ns.T1 = (S1); \
54 	__ns.T2 = (S2); __ns; })
55 #define _NS3(D, T1, S1, T2, S2, T3, S3) \
56 	D, ({ union drbd_state __ns; __ns = drbd_read_state(D); __ns.T1 = (S1); \
57 	__ns.T2 = (S2); __ns.T3 = (S3); __ns; })
58 
59 enum chg_state_flags {
60 	CS_HARD	         = 1 << 0,
61 	CS_VERBOSE       = 1 << 1,
62 	CS_WAIT_COMPLETE = 1 << 2,
63 	CS_SERIALIZE     = 1 << 3,
64 	CS_ORDERED       = CS_WAIT_COMPLETE + CS_SERIALIZE,
65 	CS_LOCAL_ONLY    = 1 << 4, /* Do not consider a device pair wide state change */
66 	CS_DC_ROLE       = 1 << 5, /* DC = display as connection state change */
67 	CS_DC_PEER       = 1 << 6,
68 	CS_DC_CONN       = 1 << 7,
69 	CS_DC_DISK       = 1 << 8,
70 	CS_DC_PDSK       = 1 << 9,
71 	CS_DC_SUSP       = 1 << 10,
72 	CS_DC_MASK       = CS_DC_ROLE + CS_DC_PEER + CS_DC_CONN + CS_DC_DISK + CS_DC_PDSK,
73 	CS_IGN_OUTD_FAIL = 1 << 11,
74 };
75 
76 /* drbd_dev_state and drbd_state are different types. This is to stress the
77    small difference. There is no suspended flag (.susp), and no suspended
78    while fence handler runs flas (susp_fen). */
79 union drbd_dev_state {
80 	struct {
81 #if defined(__LITTLE_ENDIAN_BITFIELD)
82 		unsigned role:2 ;   /* 3/4	 primary/secondary/unknown */
83 		unsigned peer:2 ;   /* 3/4	 primary/secondary/unknown */
84 		unsigned conn:5 ;   /* 17/32	 cstates */
85 		unsigned disk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
86 		unsigned pdsk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
87 		unsigned _unused:1 ;
88 		unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
89 		unsigned peer_isp:1 ;
90 		unsigned user_isp:1 ;
91 		unsigned _pad:11;   /* 0	 unused */
92 #elif defined(__BIG_ENDIAN_BITFIELD)
93 		unsigned _pad:11;
94 		unsigned user_isp:1 ;
95 		unsigned peer_isp:1 ;
96 		unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
97 		unsigned _unused:1 ;
98 		unsigned pdsk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
99 		unsigned disk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
100 		unsigned conn:5 ;   /* 17/32	 cstates */
101 		unsigned peer:2 ;   /* 3/4	 primary/secondary/unknown */
102 		unsigned role:2 ;   /* 3/4	 primary/secondary/unknown */
103 #else
104 # error "this endianess is not supported"
105 #endif
106 	};
107 	unsigned int i;
108 };
109 
110 extern enum drbd_state_rv drbd_change_state(struct drbd_device *device,
111 					    enum chg_state_flags f,
112 					    union drbd_state mask,
113 					    union drbd_state val);
114 extern void drbd_force_state(struct drbd_device *, union drbd_state,
115 			union drbd_state);
116 extern enum drbd_state_rv _drbd_request_state(struct drbd_device *,
117 					      union drbd_state,
118 					      union drbd_state,
119 					      enum chg_state_flags);
120 
121 extern enum drbd_state_rv
122 _drbd_request_state_holding_state_mutex(struct drbd_device *, union drbd_state,
123 					union drbd_state, enum chg_state_flags);
124 
125 extern enum drbd_state_rv __drbd_set_state(struct drbd_device *, union drbd_state,
126 					   enum chg_state_flags,
127 					   struct completion *done);
128 extern void print_st_err(struct drbd_device *, union drbd_state,
129 			union drbd_state, int);
130 
131 enum drbd_state_rv
132 _conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
133 		    enum chg_state_flags flags);
134 
135 enum drbd_state_rv
136 conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
137 		   enum chg_state_flags flags);
138 
139 extern void drbd_resume_al(struct drbd_device *device);
140 extern bool conn_all_vols_unconf(struct drbd_connection *connection);
141 
142 /**
143  * drbd_request_state() - Reqest a state change
144  * @device:	DRBD device.
145  * @mask:	mask of state bits to change.
146  * @val:	value of new state bits.
147  *
148  * This is the most graceful way of requesting a state change. It is verbose
149  * quite verbose in case the state change is not possible, and all those
150  * state changes are globally serialized.
151  */
152 static inline int drbd_request_state(struct drbd_device *device,
153 				     union drbd_state mask,
154 				     union drbd_state val)
155 {
156 	return _drbd_request_state(device, mask, val, CS_VERBOSE + CS_ORDERED);
157 }
158 
159 enum drbd_role conn_highest_role(struct drbd_connection *connection);
160 enum drbd_role conn_highest_peer(struct drbd_connection *connection);
161 enum drbd_disk_state conn_highest_disk(struct drbd_connection *connection);
162 enum drbd_disk_state conn_lowest_disk(struct drbd_connection *connection);
163 enum drbd_disk_state conn_highest_pdsk(struct drbd_connection *connection);
164 enum drbd_conns conn_lowest_conn(struct drbd_connection *connection);
165 
166 #endif
167