v4.19.13 snapshot.
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
new file mode 100644
index 0000000..2d02593
--- /dev/null
+++ b/include/linux/drbd.h
@@ -0,0 +1,411 @@
+/*
+  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 "8.4.10"
+#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