include/linux/drbd.h - kernel/msm-5.4 - Gitiles

 /*
   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 "8.4.11"
 #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
	/*
	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 "8.4.11"
	#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