include/linux/drbd.h

   1 /*
   2   drbd.h
   3   Kernel module for 2.6.x Kernels
   4
   5   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   6
   7   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   8   Copyright (C) 2001-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   9   Copyright (C) 2001-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
  10
  11   drbd is free software; you can redistribute it and/or modify
  12   it under the terms of the GNU General Public License as published by
  13   the Free Software Foundation; either version 2, or (at your option)
  14   any later version.
  15
  16   drbd is distributed in the hope that it will be useful,
  17   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19   GNU General Public License for more details.
  20
  21   You should have received a copy of the GNU General Public License
  22   along with drbd; see the file COPYING.  If not, write to
  23   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 */
  26 #ifndef DRBD_H
  27 #define DRBD_H
  28 #include <linux/connector.h>
  29 #include <asm/types.h>
  30
  31 #ifdef __KERNEL__
  32 #include <linux/types.h>
  33 #include <asm/byteorder.h>
  34 #else
  35 #include <sys/types.h>
  36 #include <sys/wait.h>
  37 #include <limits.h>
  38
  39 /* Although the Linux source code makes a difference between
  40    generic endianness and the bitfields' endianness, there is no
  41    architecture as of Linux-2.6.24-rc4 where the bitfields' endianness
  42    does not match the generic endianness. */
  43
  44 #if __BYTE_ORDER == __LITTLE_ENDIAN
  45 #define __LITTLE_ENDIAN_BITFIELD
  46 #elif __BYTE_ORDER == __BIG_ENDIAN
  47 #define __BIG_ENDIAN_BITFIELD
  48 #else
  49 # error "sorry, weird endianness on this box"
  50 #endif
  51
  52 #endif
  53
  54 extern const char *drbd_buildtag(void);
  55 #define REL_VERSION "8.4.3"
  56 #define API_VERSION 1
  57 #define PRO_VERSION_MIN 86
  58 #define PRO_VERSION_MAX 101
  59
  60
  61 enum drbd_io_error_p {
  62         EP_PASS_ON, /* FIXME should the better be named "Ignore"? */
  63         EP_CALL_HELPER,
  64         EP_DETACH
  65 };
  66
  67 enum drbd_fencing_p {
  68         FP_NOT_AVAIL = -1, /* Not a policy */
  69         FP_DONT_CARE = 0,
  70         FP_RESOURCE,
  71         FP_STONITH
  72 };
  73
  74 enum drbd_disconnect_p {
  75         DP_RECONNECT,
  76         DP_DROP_NET_CONF,
  77         DP_FREEZE_IO
  78 };
  79
  80 enum drbd_after_sb_p {
  81         ASB_DISCONNECT,
  82         ASB_DISCARD_YOUNGER_PRI,
  83         ASB_DISCARD_OLDER_PRI,
  84         ASB_DISCARD_ZERO_CHG,
  85         ASB_DISCARD_LEAST_CHG,
  86         ASB_DISCARD_LOCAL,
  87         ASB_DISCARD_REMOTE,
  88         ASB_CONSENSUS,
  89         ASB_DISCARD_SECONDARY,
  90         ASB_CALL_HELPER,
  91         ASB_VIOLENTLY
  92 };
  93
  94 enum drbd_on_no_data {
  95         OND_IO_ERROR,
  96         OND_SUSPEND_IO
  97 };
  98
  99 enum drbd_on_congestion {
 100         OC_BLOCK,
 101         OC_PULL_AHEAD,
 102         OC_DISCONNECT,
 103 };
 104
 105 enum drbd_read_balancing {
 106         RB_PREFER_LOCAL,
 107         RB_PREFER_REMOTE,
 108         RB_ROUND_ROBIN,
 109         RB_LEAST_PENDING,
 110         RB_CONGESTED_REMOTE,
 111         RB_32K_STRIPING,
 112         RB_64K_STRIPING,
 113         RB_128K_STRIPING,
 114         RB_256K_STRIPING,
 115         RB_512K_STRIPING,
 116         RB_1M_STRIPING,
 117 };
 118
 119 /* KEEP the order, do not delete or insert. Only append. */
 120 enum drbd_ret_code {
 121         ERR_CODE_BASE           = 100,
 122         NO_ERROR                = 101,
 123         ERR_LOCAL_ADDR          = 102,
 124         ERR_PEER_ADDR           = 103,
 125         ERR_OPEN_DISK           = 104,
 126         ERR_OPEN_MD_DISK        = 105,
 127         ERR_DISK_NOT_BDEV       = 107,
 128         ERR_MD_NOT_BDEV         = 108,
 129         ERR_DISK_TOO_SMALL      = 111,
 130         ERR_MD_DISK_TOO_SMALL   = 112,
 131         ERR_BDCLAIM_DISK        = 114,
 132         ERR_BDCLAIM_MD_DISK     = 115,
 133         ERR_MD_IDX_INVALID      = 116,
 134         ERR_IO_MD_DISK          = 118,
 135         ERR_MD_INVALID          = 119,
 136         ERR_AUTH_ALG            = 120,
 137         ERR_AUTH_ALG_ND         = 121,
 138         ERR_NOMEM               = 122,
 139         ERR_DISCARD_IMPOSSIBLE  = 123,
 140         ERR_DISK_CONFIGURED     = 124,
 141         ERR_NET_CONFIGURED      = 125,
 142         ERR_MANDATORY_TAG       = 126,
 143         ERR_MINOR_INVALID       = 127,
 144         ERR_INTR                = 129, /* EINTR */
 145         ERR_RESIZE_RESYNC       = 130,
 146         ERR_NO_PRIMARY          = 131,
 147         ERR_RESYNC_AFTER        = 132,
 148         ERR_RESYNC_AFTER_CYCLE  = 133,
 149         ERR_PAUSE_IS_SET        = 134,
 150         ERR_PAUSE_IS_CLEAR      = 135,
 151         ERR_PACKET_NR           = 137,
 152         ERR_NO_DISK             = 138,
 153         ERR_NOT_PROTO_C         = 139,
 154         ERR_NOMEM_BITMAP        = 140,
 155         ERR_INTEGRITY_ALG       = 141, /* DRBD 8.2 only */
 156         ERR_INTEGRITY_ALG_ND    = 142, /* DRBD 8.2 only */
 157         ERR_CPU_MASK_PARSE      = 143, /* DRBD 8.2 only */
 158         ERR_CSUMS_ALG           = 144, /* DRBD 8.2 only */
 159         ERR_CSUMS_ALG_ND        = 145, /* DRBD 8.2 only */
 160         ERR_VERIFY_ALG          = 146, /* DRBD 8.2 only */
 161         ERR_VERIFY_ALG_ND       = 147, /* DRBD 8.2 only */
 162         ERR_CSUMS_RESYNC_RUNNING= 148, /* DRBD 8.2 only */
 163         ERR_VERIFY_RUNNING      = 149, /* DRBD 8.2 only */
 164         ERR_DATA_NOT_CURRENT    = 150,
 165         ERR_CONNECTED           = 151, /* DRBD 8.3 only */
 166         ERR_PERM                = 152,
 167         ERR_NEED_APV_93         = 153,
 168         ERR_STONITH_AND_PROT_A  = 154,
 169         ERR_CONG_NOT_PROTO_A    = 155,
 170         ERR_PIC_AFTER_DEP       = 156,
 171         ERR_PIC_PEER_DEP        = 157,
 172         ERR_RES_NOT_KNOWN       = 158,
 173         ERR_RES_IN_USE          = 159,
 174         ERR_MINOR_CONFIGURED    = 160,
 175         ERR_MINOR_EXISTS        = 161,
 176         ERR_INVALID_REQUEST     = 162,
 177         ERR_NEED_APV_100        = 163,
 178         ERR_NEED_ALLOW_TWO_PRI  = 164,
 179         ERR_MD_UNCLEAN          = 165,
 180
 181         /* insert new ones above this line */
 182         AFTER_LAST_ERR_CODE
 183 };
 184
 185 #define DRBD_PROT_A   1
 186 #define DRBD_PROT_B   2
 187 #define DRBD_PROT_C   3
 188
 189 enum drbd_role {
 190         R_UNKNOWN = 0,
 191         R_PRIMARY = 1,     /* role */
 192         R_SECONDARY = 2,   /* role */
 193         R_MASK = 3,
 194 };
 195
 196 /* The order of these constants is important.
 197  * The lower ones (<C_WF_REPORT_PARAMS) indicate
 198  * that there is no socket!
 199  * >=C_WF_REPORT_PARAMS ==> There is a socket
 200  */
 201 enum drbd_conns {
 202         C_STANDALONE,
 203         C_DISCONNECTING,  /* Temporal state on the way to StandAlone. */
 204         C_UNCONNECTED,    /* >= C_UNCONNECTED -> inc_net() succeeds */
 205
 206         /* These temporal states are all used on the way
 207          * from >= C_CONNECTED to Unconnected.
 208          * The 'disconnect reason' states
 209          * I do not allow to change between them. */
 210         C_TIMEOUT,
 211         C_BROKEN_PIPE,
 212         C_NETWORK_FAILURE,
 213         C_PROTOCOL_ERROR,
 214         C_TEAR_DOWN,
 215
 216         C_WF_CONNECTION,
 217         C_WF_REPORT_PARAMS, /* we have a socket */
 218         C_CONNECTED,      /* we have introduced each other */
 219         C_STARTING_SYNC_S,  /* starting full sync by admin request. */
 220         C_STARTING_SYNC_T,  /* starting full sync by admin request. */
 221         C_WF_BITMAP_S,
 222         C_WF_BITMAP_T,
 223         C_WF_SYNC_UUID,
 224
 225         /* All SyncStates are tested with this comparison
 226          * xx >= C_SYNC_SOURCE && xx <= C_PAUSED_SYNC_T */
 227         C_SYNC_SOURCE,
 228         C_SYNC_TARGET,
 229         C_VERIFY_S,
 230         C_VERIFY_T,
 231         C_PAUSED_SYNC_S,
 232         C_PAUSED_SYNC_T,
 233
 234         C_AHEAD,
 235         C_BEHIND,
 236
 237         C_MASK = 31
 238 };
 239
 240 enum drbd_disk_state {
 241         D_DISKLESS,
 242         D_ATTACHING,      /* In the process of reading the meta-data */
 243         D_FAILED,         /* Becomes D_DISKLESS as soon as we told it the peer */
 244                         /* when >= D_FAILED it is legal to access mdev->bc */
 245         D_NEGOTIATING,    /* Late attaching state, we need to talk to the peer */
 246         D_INCONSISTENT,
 247         D_OUTDATED,
 248         D_UNKNOWN,       /* Only used for the peer, never for myself */
 249         D_CONSISTENT,     /* Might be D_OUTDATED, might be D_UP_TO_DATE ... */
 250         D_UP_TO_DATE,       /* Only this disk state allows applications' IO ! */
 251         D_MASK = 15
 252 };
 253
 254 union drbd_state {
 255 /* According to gcc's docs is the ...
 256  * The order of allocation of bit-fields within a unit (C90 6.5.2.1, C99 6.7.2.1).
 257  * Determined by ABI.
 258  * pointed out by Maxim Uvarov q<muvarov@ru.mvista.com>
 259  * even though we transmit as "cpu_to_be32(state)",
 260  * the offsets of the bitfields still need to be swapped
 261  * on different endianness.
 262  */
 263         struct {
 264 #if defined(__LITTLE_ENDIAN_BITFIELD)
 265                 unsigned role:2 ;   /* 3/4       primary/secondary/unknown */
 266                 unsigned peer:2 ;   /* 3/4       primary/secondary/unknown */
 267                 unsigned conn:5 ;   /* 17/32     cstates */
 268                 unsigned disk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
 269                 unsigned pdsk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
 270                 unsigned susp:1 ;   /* 2/2       IO suspended no/yes (by user) */
 271                 unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
 272                 unsigned peer_isp:1 ;
 273                 unsigned user_isp:1 ;
 274                 unsigned susp_nod:1 ; /* IO suspended because no data */
 275                 unsigned susp_fen:1 ; /* IO suspended because fence peer handler runs*/
 276                 unsigned _pad:9;   /* 0  unused */
 277 #elif defined(__BIG_ENDIAN_BITFIELD)
 278                 unsigned _pad:9;
 279                 unsigned susp_fen:1 ;
 280                 unsigned susp_nod:1 ;
 281                 unsigned user_isp:1 ;
 282                 unsigned peer_isp:1 ;
 283                 unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
 284                 unsigned susp:1 ;   /* 2/2       IO suspended  no/yes */
 285                 unsigned pdsk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
 286                 unsigned disk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
 287                 unsigned conn:5 ;   /* 17/32     cstates */
 288                 unsigned peer:2 ;   /* 3/4       primary/secondary/unknown */
 289                 unsigned role:2 ;   /* 3/4       primary/secondary/unknown */
 290 #else
 291 # error "this endianness is not supported"
 292 #endif
 293         };
 294         unsigned int i;
 295 };
 296
 297 enum drbd_state_rv {
 298         SS_CW_NO_NEED = 4,
 299         SS_CW_SUCCESS = 3,
 300         SS_NOTHING_TO_DO = 2,
 301         SS_SUCCESS = 1,
 302         SS_UNKNOWN_ERROR = 0, /* Used to sleep longer in _drbd_request_state */
 303         SS_TWO_PRIMARIES = -1,
 304         SS_NO_UP_TO_DATE_DISK = -2,
 305         SS_NO_LOCAL_DISK = -4,
 306         SS_NO_REMOTE_DISK = -5,
 307         SS_CONNECTED_OUTDATES = -6,
 308         SS_PRIMARY_NOP = -7,
 309         SS_RESYNC_RUNNING = -8,
 310         SS_ALREADY_STANDALONE = -9,
 311         SS_CW_FAILED_BY_PEER = -10,
 312         SS_IS_DISKLESS = -11,
 313         SS_DEVICE_IN_USE = -12,
 314         SS_NO_NET_CONFIG = -13,
 315         SS_NO_VERIFY_ALG = -14,       /* drbd-8.2 only */
 316         SS_NEED_CONNECTION = -15,    /* drbd-8.2 only */
 317         SS_LOWER_THAN_OUTDATED = -16,
 318         SS_NOT_SUPPORTED = -17,      /* drbd-8.2 only */
 319         SS_IN_TRANSIENT_STATE = -18,  /* Retry after the next state change */
 320         SS_CONCURRENT_ST_CHG = -19,   /* Concurrent cluster side state change! */
 321         SS_O_VOL_PEER_PRI = -20,
 322         SS_OUTDATE_WO_CONN = -21,
 323         SS_AFTER_LAST_ERROR = -22,    /* Keep this at bottom */
 324 };
 325
 326 /* from drbd_strings.c */
 327 extern const char *drbd_conn_str(enum drbd_conns);
 328 extern const char *drbd_role_str(enum drbd_role);
 329 extern const char *drbd_disk_str(enum drbd_disk_state);
 330 extern const char *drbd_set_st_err_str(enum drbd_state_rv);
 331
 332 #define SHARED_SECRET_MAX 64
 333
 334 #define MDF_CONSISTENT          (1 << 0)
 335 #define MDF_PRIMARY_IND         (1 << 1)
 336 #define MDF_CONNECTED_IND       (1 << 2)
 337 #define MDF_FULL_SYNC           (1 << 3)
 338 #define MDF_WAS_UP_TO_DATE      (1 << 4)
 339 #define MDF_PEER_OUT_DATED      (1 << 5)
 340 #define MDF_CRASHED_PRIMARY     (1 << 6)
 341 #define MDF_AL_CLEAN            (1 << 7)
 342 #define MDF_AL_DISABLED         (1 << 8)
 343
 344 enum drbd_uuid_index {
 345         UI_CURRENT,
 346         UI_BITMAP,
 347         UI_HISTORY_START,
 348         UI_HISTORY_END,
 349         UI_SIZE,      /* nl-packet: number of dirty bits */
 350         UI_FLAGS,     /* nl-packet: flags */
 351         UI_EXTENDED_SIZE   /* Everything. */
 352 };
 353
 354 enum drbd_timeout_flag {
 355         UT_DEFAULT      = 0,
 356         UT_DEGRADED     = 1,
 357         UT_PEER_OUTDATED = 2,
 358 };
 359
 360 #define UUID_JUST_CREATED ((__u64)4)
 361
 362 /* magic numbers used in meta data and network packets */
 363 #define DRBD_MAGIC 0x83740267
 364 #define DRBD_MAGIC_BIG 0x835a
 365 #define DRBD_MAGIC_100 0x8620ec20
 366
 367 #define DRBD_MD_MAGIC_07   (DRBD_MAGIC+3)
 368 #define DRBD_MD_MAGIC_08   (DRBD_MAGIC+4)
 369 #define DRBD_MD_MAGIC_84_UNCLEAN        (DRBD_MAGIC+5)
 370
 371
 372 /* how I came up with this magic?
 373  * base64 decode "actlog==" ;) */
 374 #define DRBD_AL_MAGIC 0x69cb65a2
 375
 376 /* these are of type "int" */
 377 #define DRBD_MD_INDEX_INTERNAL -1
 378 #define DRBD_MD_INDEX_FLEX_EXT -2
 379 #define DRBD_MD_INDEX_FLEX_INT -3
 380
 381 #endif