/*
    drbd.h
    Kernel module for 2.6.x Kernels
  
    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
  
    Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
    Copyright (C) 2001-2008, Philipp Reisner <philipp.reisner@linbit.com>.
    Copyright (C) 2001-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
  
    drbd is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2, or (at your option)
    any later version.
  
    drbd is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
  
    You should have received a copy of the GNU General Public License
    along with drbd; see the file COPYING.  If not, write to
    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  
  */
  #ifndef DRBD_H
  #define DRBD_H

  #include <asm/types.h>
  
  #ifdef __KERNEL__
  #include <linux/types.h>
  #include <asm/byteorder.h>
  #else
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <limits.h>

  /* Although the Linux source code makes a difference between

     generic endianness and the bitfields' endianness, there is no

     architecture as of Linux-2.6.24-rc4 where the bitfields' endianness

     does not match the generic endianness. */
  
  #if __BYTE_ORDER == __LITTLE_ENDIAN
  #define __LITTLE_ENDIAN_BITFIELD
  #elif __BYTE_ORDER == __BIG_ENDIAN
  #define __BIG_ENDIAN_BITFIELD
  #else
  # error "sorry, weird endianness on this box"
  #endif
  
  #endif

  extern const char *drbd_buildtag(void);

  #define REL_VERSION "8.4.7"

  #define API_VERSION 1

  #define PRO_VERSION_MIN 86

  #define PRO_VERSION_MAX 101

  
  
  enum drbd_io_error_p {
  	EP_PASS_ON, /* FIXME should the better be named "Ignore"? */
  	EP_CALL_HELPER,
  	EP_DETACH
  };
  
  enum drbd_fencing_p {

  	FP_NOT_AVAIL = -1, /* Not a policy */
  	FP_DONT_CARE = 0,

  	FP_RESOURCE,
  	FP_STONITH
  };
  
  enum drbd_disconnect_p {
  	DP_RECONNECT,
  	DP_DROP_NET_CONF,
  	DP_FREEZE_IO
  };
  
  enum drbd_after_sb_p {
  	ASB_DISCONNECT,
  	ASB_DISCARD_YOUNGER_PRI,
  	ASB_DISCARD_OLDER_PRI,
  	ASB_DISCARD_ZERO_CHG,
  	ASB_DISCARD_LEAST_CHG,
  	ASB_DISCARD_LOCAL,
  	ASB_DISCARD_REMOTE,
  	ASB_CONSENSUS,
  	ASB_DISCARD_SECONDARY,
  	ASB_CALL_HELPER,
  	ASB_VIOLENTLY
  };

  enum drbd_on_no_data {
  	OND_IO_ERROR,
  	OND_SUSPEND_IO
  };

  enum drbd_on_congestion {
  	OC_BLOCK,
  	OC_PULL_AHEAD,
  	OC_DISCONNECT,
  };

  enum drbd_read_balancing {
  	RB_PREFER_LOCAL,
  	RB_PREFER_REMOTE,
  	RB_ROUND_ROBIN,
  	RB_LEAST_PENDING,
  	RB_CONGESTED_REMOTE,

  	RB_32K_STRIPING,
  	RB_64K_STRIPING,
  	RB_128K_STRIPING,
  	RB_256K_STRIPING,
  	RB_512K_STRIPING,
  	RB_1M_STRIPING,

  };

  /* KEEP the order, do not delete or insert. Only append. */

  enum drbd_ret_code {

  	ERR_CODE_BASE		= 100,
  	NO_ERROR		= 101,
  	ERR_LOCAL_ADDR		= 102,
  	ERR_PEER_ADDR		= 103,
  	ERR_OPEN_DISK		= 104,
  	ERR_OPEN_MD_DISK	= 105,
  	ERR_DISK_NOT_BDEV	= 107,
  	ERR_MD_NOT_BDEV		= 108,

  	ERR_DISK_TOO_SMALL	= 111,
  	ERR_MD_DISK_TOO_SMALL	= 112,

  	ERR_BDCLAIM_DISK	= 114,
  	ERR_BDCLAIM_MD_DISK	= 115,
  	ERR_MD_IDX_INVALID	= 116,
  	ERR_IO_MD_DISK		= 118,
  	ERR_MD_INVALID          = 119,
  	ERR_AUTH_ALG		= 120,
  	ERR_AUTH_ALG_ND		= 121,
  	ERR_NOMEM		= 122,

  	ERR_DISCARD_IMPOSSIBLE	= 123,

  	ERR_DISK_CONFIGURED	= 124,
  	ERR_NET_CONFIGURED	= 125,
  	ERR_MANDATORY_TAG	= 126,
  	ERR_MINOR_INVALID	= 127,
  	ERR_INTR		= 129, /* EINTR */
  	ERR_RESIZE_RESYNC	= 130,
  	ERR_NO_PRIMARY		= 131,

  	ERR_RESYNC_AFTER	= 132,
  	ERR_RESYNC_AFTER_CYCLE	= 133,

  	ERR_PAUSE_IS_SET	= 134,
  	ERR_PAUSE_IS_CLEAR	= 135,
  	ERR_PACKET_NR		= 137,
  	ERR_NO_DISK		= 138,
  	ERR_NOT_PROTO_C		= 139,
  	ERR_NOMEM_BITMAP	= 140,
  	ERR_INTEGRITY_ALG	= 141, /* DRBD 8.2 only */
  	ERR_INTEGRITY_ALG_ND	= 142, /* DRBD 8.2 only */
  	ERR_CPU_MASK_PARSE	= 143, /* DRBD 8.2 only */
  	ERR_CSUMS_ALG		= 144, /* DRBD 8.2 only */
  	ERR_CSUMS_ALG_ND	= 145, /* DRBD 8.2 only */
  	ERR_VERIFY_ALG		= 146, /* DRBD 8.2 only */
  	ERR_VERIFY_ALG_ND	= 147, /* DRBD 8.2 only */
  	ERR_CSUMS_RESYNC_RUNNING= 148, /* DRBD 8.2 only */
  	ERR_VERIFY_RUNNING	= 149, /* DRBD 8.2 only */
  	ERR_DATA_NOT_CURRENT	= 150,
  	ERR_CONNECTED		= 151, /* DRBD 8.3 only */

  	ERR_PERM		= 152,

  	ERR_NEED_APV_93		= 153,

  	ERR_STONITH_AND_PROT_A  = 154,

  	ERR_CONG_NOT_PROTO_A	= 155,

  	ERR_PIC_AFTER_DEP	= 156,
  	ERR_PIC_PEER_DEP	= 157,

  	ERR_RES_NOT_KNOWN	= 158,
  	ERR_RES_IN_USE		= 159,

  	ERR_MINOR_CONFIGURED    = 160,

  	ERR_MINOR_OR_VOLUME_EXISTS = 161,

  	ERR_INVALID_REQUEST	= 162,

  	ERR_NEED_APV_100	= 163,

  	ERR_NEED_ALLOW_TWO_PRI  = 164,

  	ERR_MD_UNCLEAN          = 165,

  	ERR_MD_LAYOUT_CONNECTED = 166,
  	ERR_MD_LAYOUT_TOO_BIG   = 167,
  	ERR_MD_LAYOUT_TOO_SMALL = 168,
  	ERR_MD_LAYOUT_NO_FIT    = 169,
  	ERR_IMPLICIT_SHRINK     = 170,

  	/* insert new ones above this line */
  	AFTER_LAST_ERR_CODE
  };
  
  #define DRBD_PROT_A   1
  #define DRBD_PROT_B   2
  #define DRBD_PROT_C   3
  
  enum drbd_role {
  	R_UNKNOWN = 0,
  	R_PRIMARY = 1,     /* role */
  	R_SECONDARY = 2,   /* role */
  	R_MASK = 3,
  };
  
  /* The order of these constants is important.
   * The lower ones (<C_WF_REPORT_PARAMS) indicate
   * that there is no socket!
   * >=C_WF_REPORT_PARAMS ==> There is a socket
   */
  enum drbd_conns {
  	C_STANDALONE,
  	C_DISCONNECTING,  /* Temporal state on the way to StandAlone. */
  	C_UNCONNECTED,    /* >= C_UNCONNECTED -> inc_net() succeeds */
  
  	/* These temporal states are all used on the way
  	 * from >= C_CONNECTED to Unconnected.
  	 * The 'disconnect reason' states

  	 * I do not allow to change between them. */

  	C_TIMEOUT,
  	C_BROKEN_PIPE,
  	C_NETWORK_FAILURE,
  	C_PROTOCOL_ERROR,
  	C_TEAR_DOWN,
  
  	C_WF_CONNECTION,
  	C_WF_REPORT_PARAMS, /* we have a socket */
  	C_CONNECTED,      /* we have introduced each other */
  	C_STARTING_SYNC_S,  /* starting full sync by admin request. */

  	C_STARTING_SYNC_T,  /* starting full sync by admin request. */

  	C_WF_BITMAP_S,
  	C_WF_BITMAP_T,
  	C_WF_SYNC_UUID,
  
  	/* All SyncStates are tested with this comparison
  	 * xx >= C_SYNC_SOURCE && xx <= C_PAUSED_SYNC_T */
  	C_SYNC_SOURCE,
  	C_SYNC_TARGET,
  	C_VERIFY_S,
  	C_VERIFY_T,
  	C_PAUSED_SYNC_S,
  	C_PAUSED_SYNC_T,

  
  	C_AHEAD,
  	C_BEHIND,

  	C_MASK = 31
  };
  
  enum drbd_disk_state {
  	D_DISKLESS,
  	D_ATTACHING,      /* In the process of reading the meta-data */
  	D_FAILED,         /* Becomes D_DISKLESS as soon as we told it the peer */

  			  /* when >= D_FAILED it is legal to access mdev->ldev */

  	D_NEGOTIATING,    /* Late attaching state, we need to talk to the peer */
  	D_INCONSISTENT,
  	D_OUTDATED,
  	D_UNKNOWN,       /* Only used for the peer, never for myself */
  	D_CONSISTENT,     /* Might be D_OUTDATED, might be D_UP_TO_DATE ... */
  	D_UP_TO_DATE,       /* Only this disk state allows applications' IO ! */
  	D_MASK = 15
  };
  
  union drbd_state {
  /* According to gcc's docs is the ...
   * The order of allocation of bit-fields within a unit (C90 6.5.2.1, C99 6.7.2.1).
   * Determined by ABI.
   * pointed out by Maxim Uvarov q<muvarov@ru.mvista.com>
   * even though we transmit as "cpu_to_be32(state)",
   * the offsets of the bitfields still need to be swapped

   * on different endianness.

   */
  	struct {
  #if defined(__LITTLE_ENDIAN_BITFIELD)
  		unsigned role:2 ;   /* 3/4	 primary/secondary/unknown */
  		unsigned peer:2 ;   /* 3/4	 primary/secondary/unknown */
  		unsigned conn:5 ;   /* 17/32	 cstates */
  		unsigned disk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
  		unsigned pdsk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */

  		unsigned susp:1 ;   /* 2/2	 IO suspended no/yes (by user) */

  		unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
  		unsigned peer_isp:1 ;
  		unsigned user_isp:1 ;

  		unsigned susp_nod:1 ; /* IO suspended because no data */
  		unsigned susp_fen:1 ; /* IO suspended because fence peer handler runs*/
  		unsigned _pad:9;   /* 0	 unused */

  #elif defined(__BIG_ENDIAN_BITFIELD)

  		unsigned _pad:9;
  		unsigned susp_fen:1 ;
  		unsigned susp_nod:1 ;

  		unsigned user_isp:1 ;
  		unsigned peer_isp:1 ;
  		unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
  		unsigned susp:1 ;   /* 2/2	 IO suspended  no/yes */
  		unsigned pdsk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
  		unsigned disk:4 ;   /* 8/16	 from D_DISKLESS to D_UP_TO_DATE */
  		unsigned conn:5 ;   /* 17/32	 cstates */
  		unsigned peer:2 ;   /* 3/4	 primary/secondary/unknown */
  		unsigned role:2 ;   /* 3/4	 primary/secondary/unknown */
  #else

  # error "this endianness is not supported"

  #endif
  	};
  	unsigned int i;
  };

  enum drbd_state_rv {

  	SS_CW_NO_NEED = 4,
  	SS_CW_SUCCESS = 3,
  	SS_NOTHING_TO_DO = 2,
  	SS_SUCCESS = 1,
  	SS_UNKNOWN_ERROR = 0, /* Used to sleep longer in _drbd_request_state */
  	SS_TWO_PRIMARIES = -1,
  	SS_NO_UP_TO_DATE_DISK = -2,
  	SS_NO_LOCAL_DISK = -4,
  	SS_NO_REMOTE_DISK = -5,
  	SS_CONNECTED_OUTDATES = -6,
  	SS_PRIMARY_NOP = -7,
  	SS_RESYNC_RUNNING = -8,
  	SS_ALREADY_STANDALONE = -9,
  	SS_CW_FAILED_BY_PEER = -10,
  	SS_IS_DISKLESS = -11,
  	SS_DEVICE_IN_USE = -12,
  	SS_NO_NET_CONFIG = -13,
  	SS_NO_VERIFY_ALG = -14,       /* drbd-8.2 only */
  	SS_NEED_CONNECTION = -15,    /* drbd-8.2 only */
  	SS_LOWER_THAN_OUTDATED = -16,
  	SS_NOT_SUPPORTED = -17,      /* drbd-8.2 only */
  	SS_IN_TRANSIENT_STATE = -18,  /* Retry after the next state change */
  	SS_CONCURRENT_ST_CHG = -19,   /* Concurrent cluster side state change! */

  	SS_O_VOL_PEER_PRI = -20,

  	SS_OUTDATE_WO_CONN = -21,
  	SS_AFTER_LAST_ERROR = -22,    /* Keep this at bottom */

  };

  #define SHARED_SECRET_MAX 64
  
  #define MDF_CONSISTENT		(1 << 0)
  #define MDF_PRIMARY_IND		(1 << 1)
  #define MDF_CONNECTED_IND	(1 << 2)
  #define MDF_FULL_SYNC		(1 << 3)
  #define MDF_WAS_UP_TO_DATE	(1 << 4)
  #define MDF_PEER_OUT_DATED	(1 << 5)

  #define MDF_CRASHED_PRIMARY	(1 << 6)
  #define MDF_AL_CLEAN		(1 << 7)

  #define MDF_AL_DISABLED		(1 << 8)

  #define MAX_PEERS 32

  enum drbd_uuid_index {
  	UI_CURRENT,
  	UI_BITMAP,
  	UI_HISTORY_START,
  	UI_HISTORY_END,
  	UI_SIZE,      /* nl-packet: number of dirty bits */
  	UI_FLAGS,     /* nl-packet: flags */
  	UI_EXTENDED_SIZE   /* Everything. */
  };

  #define HISTORY_UUIDS MAX_PEERS

  enum drbd_timeout_flag {
  	UT_DEFAULT      = 0,
  	UT_DEGRADED     = 1,
  	UT_PEER_OUTDATED = 2,
  };

  enum drbd_notification_type {
  	NOTIFY_EXISTS,
  	NOTIFY_CREATE,
  	NOTIFY_CHANGE,
  	NOTIFY_DESTROY,
  	NOTIFY_CALL,
  	NOTIFY_RESPONSE,
  
  	NOTIFY_CONTINUES = 0x8000,
  	NOTIFY_FLAGS = NOTIFY_CONTINUES,
  };

  enum drbd_peer_state {
  	P_INCONSISTENT = 3,
  	P_OUTDATED = 4,
  	P_DOWN = 5,
  	P_PRIMARY = 6,
  	P_FENCING = 7,
  };

  #define UUID_JUST_CREATED ((__u64)4)

  enum write_ordering_e {
  	WO_NONE,
  	WO_DRAIN_IO,
  	WO_BDEV_FLUSH,
  	WO_BIO_BARRIER
  };

  /* magic numbers used in meta data and network packets */

  #define DRBD_MAGIC 0x83740267

  #define DRBD_MAGIC_BIG 0x835a

  #define DRBD_MAGIC_100 0x8620ec20

  #define DRBD_MD_MAGIC_07   (DRBD_MAGIC+3)
  #define DRBD_MD_MAGIC_08   (DRBD_MAGIC+4)
  #define DRBD_MD_MAGIC_84_UNCLEAN	(DRBD_MAGIC+5)

  /* how I came up with this magic?
   * base64 decode "actlog==" ;) */
  #define DRBD_AL_MAGIC 0x69cb65a2

  /* these are of type "int" */
  #define DRBD_MD_INDEX_INTERNAL -1
  #define DRBD_MD_INDEX_FLEX_EXT -2
  #define DRBD_MD_INDEX_FLEX_INT -3

  #define DRBD_CPU_MASK_SIZE 32

  #endif