xref: /linux/drivers/block/drbd/drbd_state.h (revision 41e0d49104dbff888ef6446ea46842fde66c0a76)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef DRBD_STATE_H
3 #define DRBD_STATE_H
4 
5 struct drbd_device;
6 struct drbd_connection;
7 
8 /**
9  * DOC: DRBD State macros
10  *
11  * These macros are used to express state changes in easily readable form.
12  *
13  * The NS macros expand to a mask and a value, that can be bit ored onto the
14  * current state as soon as the spinlock (req_lock) was taken.
15  *
16  * The _NS macros are used for state functions that get called with the
17  * spinlock. These macros expand directly to the new state value.
18  *
19  * Besides the basic forms NS() and _NS() additional _?NS[23] are defined
20  * to express state changes that affect more than one aspect of the state.
21  *
22  * E.g. NS2(conn, C_CONNECTED, peer, R_SECONDARY)
23  * Means that the network connection was established and that the peer
24  * is in secondary role.
25  */
26 #define role_MASK R_MASK
27 #define peer_MASK R_MASK
28 #define disk_MASK D_MASK
29 #define pdsk_MASK D_MASK
30 #define conn_MASK C_MASK
31 #define susp_MASK 1
32 #define user_isp_MASK 1
33 #define aftr_isp_MASK 1
34 #define susp_nod_MASK 1
35 #define susp_fen_MASK 1
36 
37 #define NS(T, S) \
38 	({ union drbd_state mask; mask.i = 0; mask.T = T##_MASK; mask; }), \
39 	({ union drbd_state val; val.i = 0; val.T = (S); val; })
40 #define NS2(T1, S1, T2, S2) \
41 	({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \
42 	  mask.T2 = T2##_MASK; mask; }), \
43 	({ union drbd_state val; val.i = 0; val.T1 = (S1); \
44 	  val.T2 = (S2); val; })
45 #define NS3(T1, S1, T2, S2, T3, S3) \
46 	({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \
47 	  mask.T2 = T2##_MASK; mask.T3 = T3##_MASK; mask; }), \
48 	({ union drbd_state val;  val.i = 0; val.T1 = (S1); \
49 	  val.T2 = (S2); val.T3 = (S3); val; })
50 
51 #define _NS(D, T, S) \
52 	D, ({ union drbd_state __ns; __ns = drbd_read_state(D); __ns.T = (S); __ns; })
53 #define _NS2(D, T1, S1, T2, S2) \
54 	D, ({ union drbd_state __ns; __ns = drbd_read_state(D); __ns.T1 = (S1); \
55 	__ns.T2 = (S2); __ns; })
56 #define _NS3(D, T1, S1, T2, S2, T3, S3) \
57 	D, ({ union drbd_state __ns; __ns = drbd_read_state(D); __ns.T1 = (S1); \
58 	__ns.T2 = (S2); __ns.T3 = (S3); __ns; })
59 
60 enum chg_state_flags {
61 	CS_HARD	         = 1 << 0,
62 	CS_VERBOSE       = 1 << 1,
63 	CS_WAIT_COMPLETE = 1 << 2,
64 	CS_SERIALIZE     = 1 << 3,
65 	CS_ORDERED       = CS_WAIT_COMPLETE + CS_SERIALIZE,
66 	CS_LOCAL_ONLY    = 1 << 4, /* Do not consider a device pair wide state change */
67 	CS_DC_ROLE       = 1 << 5, /* DC = display as connection state change */
68 	CS_DC_PEER       = 1 << 6,
69 	CS_DC_CONN       = 1 << 7,
70 	CS_DC_DISK       = 1 << 8,
71 	CS_DC_PDSK       = 1 << 9,
72 	CS_DC_SUSP       = 1 << 10,
73 	CS_DC_MASK       = CS_DC_ROLE + CS_DC_PEER + CS_DC_CONN + CS_DC_DISK + CS_DC_PDSK,
74 	CS_IGN_OUTD_FAIL = 1 << 11,
75 
76 	/* Make sure no meta data IO is in flight, by calling
77 	 * drbd_md_get_buffer().  Used for graceful detach. */
78 	CS_INHIBIT_MD_IO = 1 << 12,
79 };
80 
81 /* drbd_dev_state and drbd_state are different types. This is to stress the
82    small difference. There is no suspended flag (.susp), and no suspended
83    while fence handler runs flas (susp_fen). */
84 union drbd_dev_state {
85 	struct {
86 #if defined(__LITTLE_ENDIAN_BITFIELD)
87 		unsigned role:2 ;   /* 3/4	 primary/secondary/unknown */
88 		unsigned peer:2 ;   /* 3/4	 primary/secondary/unknown */
89 		unsigned conn:5 ;   /* 17/32	 cstates */
90 		unsigned disk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
91 		unsigned pdsk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
92 		unsigned _unused:1 ;
93 		unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
94 		unsigned peer_isp:1 ;
95 		unsigned user_isp:1 ;
96 		unsigned _pad:11;   /* 0	 unused */
97 #elif defined(__BIG_ENDIAN_BITFIELD)
98 		unsigned _pad:11;
99 		unsigned user_isp:1 ;
100 		unsigned peer_isp:1 ;
101 		unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
102 		unsigned _unused:1 ;
103 		unsigned pdsk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
104 		unsigned disk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
105 		unsigned conn:5 ;   /* 17/32	 cstates */
106 		unsigned peer:2 ;   /* 3/4	 primary/secondary/unknown */
107 		unsigned role:2 ;   /* 3/4	 primary/secondary/unknown */
108 #else
109 # error "this endianess is not supported"
110 #endif
111 	};
112 	unsigned int i;
113 };
114 
115 extern enum drbd_state_rv drbd_change_state(struct drbd_device *device,
116 					    enum chg_state_flags f,
117 					    union drbd_state mask,
118 					    union drbd_state val);
119 extern void drbd_force_state(struct drbd_device *, union drbd_state,
120 			union drbd_state);
121 extern enum drbd_state_rv _drbd_request_state(struct drbd_device *,
122 					      union drbd_state,
123 					      union drbd_state,
124 					      enum chg_state_flags);
125 
126 extern enum drbd_state_rv
127 _drbd_request_state_holding_state_mutex(struct drbd_device *, union drbd_state,
128 					union drbd_state, enum chg_state_flags);
129 
130 extern enum drbd_state_rv _drbd_set_state(struct drbd_device *, union drbd_state,
131 					  enum chg_state_flags,
132 					  struct completion *done);
133 extern void print_st_err(struct drbd_device *, union drbd_state,
134 			union drbd_state, enum drbd_state_rv);
135 
136 enum drbd_state_rv
137 _conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
138 		    enum chg_state_flags flags);
139 
140 enum drbd_state_rv
141 conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
142 		   enum chg_state_flags flags);
143 
144 extern void drbd_resume_al(struct drbd_device *device);
145 extern bool conn_all_vols_unconf(struct drbd_connection *connection);
146 
147 /**
148  * drbd_request_state() - Request a state change
149  * @device:	DRBD device.
150  * @mask:	mask of state bits to change.
151  * @val:	value of new state bits.
152  *
153  * This is the most graceful way of requesting a state change. It is verbose
154  * quite verbose in case the state change is not possible, and all those
155  * state changes are globally serialized.
156  */
157 static inline int drbd_request_state(struct drbd_device *device,
158 				     union drbd_state mask,
159 				     union drbd_state val)
160 {
161 	return _drbd_request_state(device, mask, val, CS_VERBOSE + CS_ORDERED);
162 }
163 
164 /* for use in adm_detach() (drbd_adm_detach(), drbd_adm_down()) */
165 int drbd_request_detach_interruptible(struct drbd_device *device);
166 
167 enum drbd_role conn_highest_role(struct drbd_connection *connection);
168 enum drbd_role conn_highest_peer(struct drbd_connection *connection);
169 enum drbd_disk_state conn_highest_disk(struct drbd_connection *connection);
170 enum drbd_disk_state conn_lowest_disk(struct drbd_connection *connection);
171 enum drbd_disk_state conn_highest_pdsk(struct drbd_connection *connection);
172 enum drbd_conns conn_lowest_conn(struct drbd_connection *connection);
173 
174 #endif
175