drivers/block/drbd/drbd_state.h

   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         /* Make sure no meta data IO is in flight, by calling
  76          * drbd_md_get_buffer().  Used for graceful detach. */
  77         CS_INHIBIT_MD_IO = 1 << 12,
  78 };
  79
  80 /* drbd_dev_state and drbd_state are different types. This is to stress the
  81    small difference. There is no suspended flag (.susp), and no suspended
  82    while fence handler runs flas (susp_fen). */
  83 union drbd_dev_state {
  84         struct {
  85 #if defined(__LITTLE_ENDIAN_BITFIELD)
  86                 unsigned role:2 ;   /* 3/4       primary/secondary/unknown */
  87                 unsigned peer:2 ;   /* 3/4       primary/secondary/unknown */
  88                 unsigned conn:5 ;   /* 17/32     cstates */
  89                 unsigned disk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
  90                 unsigned pdsk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
  91                 unsigned _unused:1 ;
  92                 unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
  93                 unsigned peer_isp:1 ;
  94                 unsigned user_isp:1 ;
  95                 unsigned _pad:11;   /* 0         unused */
  96 #elif defined(__BIG_ENDIAN_BITFIELD)
  97                 unsigned _pad:11;
  98                 unsigned user_isp:1 ;
  99                 unsigned peer_isp:1 ;
 100                 unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
 101                 unsigned _unused:1 ;
 102                 unsigned pdsk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
 103                 unsigned disk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
 104                 unsigned conn:5 ;   /* 17/32     cstates */
 105                 unsigned peer:2 ;   /* 3/4       primary/secondary/unknown */
 106                 unsigned role:2 ;   /* 3/4       primary/secondary/unknown */
 107 #else
 108 # error "this endianess is not supported"
 109 #endif
 110         };
 111         unsigned int i;
 112 };
 113
 114 extern enum drbd_state_rv drbd_change_state(struct drbd_device *device,
 115                                             enum chg_state_flags f,
 116                                             union drbd_state mask,
 117                                             union drbd_state val);
 118 extern void drbd_force_state(struct drbd_device *, union drbd_state,
 119                         union drbd_state);
 120 extern enum drbd_state_rv _drbd_request_state(struct drbd_device *,
 121                                               union drbd_state,
 122                                               union drbd_state,
 123                                               enum chg_state_flags);
 124
 125 extern enum drbd_state_rv
 126 _drbd_request_state_holding_state_mutex(struct drbd_device *, union drbd_state,
 127                                         union drbd_state, enum chg_state_flags);
 128
 129 extern enum drbd_state_rv _drbd_set_state(struct drbd_device *, union drbd_state,
 130                                           enum chg_state_flags,
 131                                           struct completion *done);
 132 extern void print_st_err(struct drbd_device *, union drbd_state,
 133                         union drbd_state, int);
 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 enum drbd_state_rv
 140 conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
 141                    enum chg_state_flags flags);
 142
 143 extern void drbd_resume_al(struct drbd_device *device);
 144 extern bool conn_all_vols_unconf(struct drbd_connection *connection);
 145
 146 /**
 147  * drbd_request_state() - Request a state change
 148  * @device:     DRBD device.
 149  * @mask:       mask of state bits to change.
 150  * @val:        value of new state bits.
 151  *
 152  * This is the most graceful way of requesting a state change. It is verbose
 153  * quite verbose in case the state change is not possible, and all those
 154  * state changes are globally serialized.
 155  */
 156 static inline int drbd_request_state(struct drbd_device *device,
 157                                      union drbd_state mask,
 158                                      union drbd_state val)
 159 {
 160         return _drbd_request_state(device, mask, val, CS_VERBOSE + CS_ORDERED);
 161 }
 162
 163 /* for use in adm_detach() (drbd_adm_detach(), drbd_adm_down()) */
 164 enum drbd_state_rv
 165 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