drbd: Split off on-the-wire protocol definitions
Keep the protocol definitions separate from the kernel code; they are useful in
their own right.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 27df55f..80394b7 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -46,6 +46,7 @@
#include <linux/drbd_genl_api.h>
#include <linux/drbd.h>
#include "drbd_state.h"
+#include "drbd_protocol.h"
#ifdef __CHECKER__
# define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr")))
@@ -168,72 +169,6 @@
extern struct idr minors; /* RCU, updates: genl_lock() */
extern struct list_head drbd_tconns; /* RCU, updates: genl_lock() */
-/* on the wire */
-enum drbd_packet {
- /* receiver (data socket) */
- P_DATA = 0x00,
- P_DATA_REPLY = 0x01, /* Response to P_DATA_REQUEST */
- P_RS_DATA_REPLY = 0x02, /* Response to P_RS_DATA_REQUEST */
- P_BARRIER = 0x03,
- P_BITMAP = 0x04,
- P_BECOME_SYNC_TARGET = 0x05,
- P_BECOME_SYNC_SOURCE = 0x06,
- P_UNPLUG_REMOTE = 0x07, /* Used at various times to hint the peer */
- P_DATA_REQUEST = 0x08, /* Used to ask for a data block */
- P_RS_DATA_REQUEST = 0x09, /* Used to ask for a data block for resync */
- P_SYNC_PARAM = 0x0a,
- P_PROTOCOL = 0x0b,
- P_UUIDS = 0x0c,
- P_SIZES = 0x0d,
- P_STATE = 0x0e,
- P_SYNC_UUID = 0x0f,
- P_AUTH_CHALLENGE = 0x10,
- P_AUTH_RESPONSE = 0x11,
- P_STATE_CHG_REQ = 0x12,
-
- /* asender (meta socket */
- P_PING = 0x13,
- P_PING_ACK = 0x14,
- P_RECV_ACK = 0x15, /* Used in protocol B */
- P_WRITE_ACK = 0x16, /* Used in protocol C */
- P_RS_WRITE_ACK = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */
- P_SUPERSEDED = 0x18, /* Used in proto C, two-primaries conflict detection */
- P_NEG_ACK = 0x19, /* Sent if local disk is unusable */
- P_NEG_DREPLY = 0x1a, /* Local disk is broken... */
- P_NEG_RS_DREPLY = 0x1b, /* Local disk is broken... */
- P_BARRIER_ACK = 0x1c,
- P_STATE_CHG_REPLY = 0x1d,
-
- /* "new" commands, no longer fitting into the ordering scheme above */
-
- P_OV_REQUEST = 0x1e, /* data socket */
- P_OV_REPLY = 0x1f,
- P_OV_RESULT = 0x20, /* meta socket */
- P_CSUM_RS_REQUEST = 0x21, /* data socket */
- P_RS_IS_IN_SYNC = 0x22, /* meta socket */
- P_SYNC_PARAM89 = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
- P_COMPRESSED_BITMAP = 0x24, /* compressed or otherwise encoded bitmap transfer */
- /* P_CKPT_FENCE_REQ = 0x25, * currently reserved for protocol D */
- /* P_CKPT_DISABLE_REQ = 0x26, * currently reserved for protocol D */
- P_DELAY_PROBE = 0x27, /* is used on BOTH sockets */
- P_OUT_OF_SYNC = 0x28, /* Mark as out of sync (Outrunning), data socket */
- P_RS_CANCEL = 0x29, /* meta: Used to cancel RS_DATA_REQUEST packet by SyncSource */
- P_CONN_ST_CHG_REQ = 0x2a, /* data sock: Connection wide state request */
- P_CONN_ST_CHG_REPLY = 0x2b, /* meta sock: Connection side state req reply */
- P_RETRY_WRITE = 0x2c, /* Protocol C: retry conflicting write request */
- P_PROTOCOL_UPDATE = 0x2d, /* data sock: is used in established connections */
-
- P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
- P_MAX_OPT_CMD = 0x101,
-
- /* special command ids for handshake */
-
- P_INITIAL_META = 0xfff1, /* First Packet on the MetaSock */
- P_INITIAL_DATA = 0xfff2, /* First Packet on the Socket */
-
- P_CONNECTION_FEATURES = 0xfffe /* FIXED for the next century! */
-};
-
extern const char *cmdname(enum drbd_packet cmd);
/* for sending/receiving the bitmap,
@@ -276,234 +211,8 @@
#endif
}
-#ifndef __packed
-#define __packed __attribute__((packed))
-#endif
-
-/* This is the layout for a packet on the wire.
- * The byteorder is the network byte order.
- * (except block_id and barrier fields.
- * these are pointers to local structs
- * and have no relevance for the partner,
- * which just echoes them as received.)
- *
- * NOTE that the payload starts at a long aligned offset,
- * regardless of 32 or 64 bit arch!
- */
-struct p_header80 {
- u32 magic;
- u16 command;
- u16 length; /* bytes of data after this header */
-} __packed;
-
-/* Header for big packets, Used for data packets exceeding 64kB */
-struct p_header95 {
- u16 magic; /* use DRBD_MAGIC_BIG here */
- u16 command;
- u32 length;
-} __packed;
-
-struct p_header100 {
- u32 magic;
- u16 volume;
- u16 command;
- u32 length;
- u32 pad;
-} __packed;
-
extern unsigned int drbd_header_size(struct drbd_tconn *tconn);
-/* these defines must not be changed without changing the protocol version */
-#define DP_HARDBARRIER 1 /* depricated */
-#define DP_RW_SYNC 2 /* equals REQ_SYNC */
-#define DP_MAY_SET_IN_SYNC 4
-#define DP_UNPLUG 8 /* not used anymore */
-#define DP_FUA 16 /* equals REQ_FUA */
-#define DP_FLUSH 32 /* equals REQ_FLUSH */
-#define DP_DISCARD 64 /* equals REQ_DISCARD */
-#define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */
-#define DP_SEND_WRITE_ACK 256 /* This is a proto C write request */
-
-struct p_data {
- u64 sector; /* 64 bits sector number */
- u64 block_id; /* to identify the request in protocol B&C */
- u32 seq_num;
- u32 dp_flags;
-} __packed;
-
-/*
- * commands which share a struct:
- * p_block_ack:
- * P_RECV_ACK (proto B), P_WRITE_ACK (proto C),
- * P_SUPERSEDED (proto C, two-primaries conflict detection)
- * p_block_req:
- * P_DATA_REQUEST, P_RS_DATA_REQUEST
- */
-struct p_block_ack {
- u64 sector;
- u64 block_id;
- u32 blksize;
- u32 seq_num;
-} __packed;
-
-struct p_block_req {
- u64 sector;
- u64 block_id;
- u32 blksize;
- u32 pad; /* to multiple of 8 Byte */
-} __packed;
-
-/*
- * commands with their own struct for additional fields:
- * P_CONNECTION_FEATURES
- * P_BARRIER
- * P_BARRIER_ACK
- * P_SYNC_PARAM
- * ReportParams
- */
-
-struct p_connection_features {
- u32 protocol_min;
- u32 feature_flags;
- u32 protocol_max;
-
- /* should be more than enough for future enhancements
- * for now, feature_flags and the reserved array shall be zero.
- */
-
- u32 _pad;
- u64 reserved[7];
-} __packed;
-
-struct p_barrier {
- u32 barrier; /* barrier number _handle_ only */
- u32 pad; /* to multiple of 8 Byte */
-} __packed;
-
-struct p_barrier_ack {
- u32 barrier;
- u32 set_size;
-} __packed;
-
-struct p_rs_param {
- u32 resync_rate;
-
- /* Since protocol version 88 and higher. */
- char verify_alg[0];
-} __packed;
-
-struct p_rs_param_89 {
- u32 resync_rate;
- /* protocol version 89: */
- char verify_alg[SHARED_SECRET_MAX];
- char csums_alg[SHARED_SECRET_MAX];
-} __packed;
-
-struct p_rs_param_95 {
- u32 resync_rate;
- char verify_alg[SHARED_SECRET_MAX];
- char csums_alg[SHARED_SECRET_MAX];
- u32 c_plan_ahead;
- u32 c_delay_target;
- u32 c_fill_target;
- u32 c_max_rate;
-} __packed;
-
-enum drbd_conn_flags {
- CF_DISCARD_MY_DATA = 1,
- CF_DRY_RUN = 2,
-};
-
-struct p_protocol {
- u32 protocol;
- u32 after_sb_0p;
- u32 after_sb_1p;
- u32 after_sb_2p;
- u32 conn_flags;
- u32 two_primaries;
-
- /* Since protocol version 87 and higher. */
- char integrity_alg[0];
-
-} __packed;
-
-struct p_uuids {
- u64 uuid[UI_EXTENDED_SIZE];
-} __packed;
-
-struct p_rs_uuid {
- u64 uuid;
-} __packed;
-
-struct p_sizes {
- u64 d_size; /* size of disk */
- u64 u_size; /* user requested size */
- u64 c_size; /* current exported size */
- u32 max_bio_size; /* Maximal size of a BIO */
- u16 queue_order_type; /* not yet implemented in DRBD*/
- u16 dds_flags; /* use enum dds_flags here. */
-} __packed;
-
-struct p_state {
- u32 state;
-} __packed;
-
-struct p_req_state {
- u32 mask;
- u32 val;
-} __packed;
-
-struct p_req_state_reply {
- u32 retcode;
-} __packed;
-
-struct p_drbd06_param {
- u64 size;
- u32 state;
- u32 blksize;
- u32 protocol;
- u32 version;
- u32 gen_cnt[5];
- u32 bit_map_gen[5];
-} __packed;
-
-struct p_block_desc {
- u64 sector;
- u32 blksize;
- u32 pad; /* to multiple of 8 Byte */
-} __packed;
-
-/* Valid values for the encoding field.
- * Bump proto version when changing this. */
-enum drbd_bitmap_code {
- /* RLE_VLI_Bytes = 0,
- * and other bit variants had been defined during
- * algorithm evaluation. */
- RLE_VLI_Bits = 2,
-};
-
-struct p_compressed_bm {
- /* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code
- * (encoding & 0x80): polarity (set/unset) of first runlength
- * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits
- * used to pad up to head.length bytes
- */
- u8 encoding;
-
- u8 code[0];
-} __packed;
-
-struct p_delay_probe93 {
- u32 seq_num; /* sequence number to match the two probe packets */
- u32 offset; /* usecs the probe got sent after the reference time point */
-} __packed;
-
-/*
- * Bitmap packets need to fit within a single page on the sender and receiver,
- * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
- */
-#define DRBD_SOCKET_BUFFER_SIZE 4096
-
/**********************************************************************/
enum drbd_thread_state {
NONE,
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index c0b8b24..2a8e703 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -52,6 +52,7 @@
#include <linux/drbd_limits.h>
#include "drbd_int.h"
+#include "drbd_protocol.h"
#include "drbd_req.h" /* only for _req_mod in tl_release and tl_clear */
#include "drbd_vli.h"
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index ff096c9..97a2227 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -32,6 +32,7 @@
#include <linux/blkpg.h>
#include <linux/cpumask.h>
#include "drbd_int.h"
+#include "drbd_protocol.h"
#include "drbd_req.h"
#include "drbd_wrappers.h"
#include <asm/unaligned.h>
diff --git a/drivers/block/drbd/drbd_protocol.h b/drivers/block/drbd/drbd_protocol.h
new file mode 100644
index 0000000..3c04ec0
--- /dev/null
+++ b/drivers/block/drbd/drbd_protocol.h
@@ -0,0 +1,295 @@
+#ifndef __DRBD_PROTOCOL_H
+#define __DRBD_PROTOCOL_H
+
+enum drbd_packet {
+ /* receiver (data socket) */
+ P_DATA = 0x00,
+ P_DATA_REPLY = 0x01, /* Response to P_DATA_REQUEST */
+ P_RS_DATA_REPLY = 0x02, /* Response to P_RS_DATA_REQUEST */
+ P_BARRIER = 0x03,
+ P_BITMAP = 0x04,
+ P_BECOME_SYNC_TARGET = 0x05,
+ P_BECOME_SYNC_SOURCE = 0x06,
+ P_UNPLUG_REMOTE = 0x07, /* Used at various times to hint the peer */
+ P_DATA_REQUEST = 0x08, /* Used to ask for a data block */
+ P_RS_DATA_REQUEST = 0x09, /* Used to ask for a data block for resync */
+ P_SYNC_PARAM = 0x0a,
+ P_PROTOCOL = 0x0b,
+ P_UUIDS = 0x0c,
+ P_SIZES = 0x0d,
+ P_STATE = 0x0e,
+ P_SYNC_UUID = 0x0f,
+ P_AUTH_CHALLENGE = 0x10,
+ P_AUTH_RESPONSE = 0x11,
+ P_STATE_CHG_REQ = 0x12,
+
+ /* asender (meta socket */
+ P_PING = 0x13,
+ P_PING_ACK = 0x14,
+ P_RECV_ACK = 0x15, /* Used in protocol B */
+ P_WRITE_ACK = 0x16, /* Used in protocol C */
+ P_RS_WRITE_ACK = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */
+ P_SUPERSEDED = 0x18, /* Used in proto C, two-primaries conflict detection */
+ P_NEG_ACK = 0x19, /* Sent if local disk is unusable */
+ P_NEG_DREPLY = 0x1a, /* Local disk is broken... */
+ P_NEG_RS_DREPLY = 0x1b, /* Local disk is broken... */
+ P_BARRIER_ACK = 0x1c,
+ P_STATE_CHG_REPLY = 0x1d,
+
+ /* "new" commands, no longer fitting into the ordering scheme above */
+
+ P_OV_REQUEST = 0x1e, /* data socket */
+ P_OV_REPLY = 0x1f,
+ P_OV_RESULT = 0x20, /* meta socket */
+ P_CSUM_RS_REQUEST = 0x21, /* data socket */
+ P_RS_IS_IN_SYNC = 0x22, /* meta socket */
+ P_SYNC_PARAM89 = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
+ P_COMPRESSED_BITMAP = 0x24, /* compressed or otherwise encoded bitmap transfer */
+ /* P_CKPT_FENCE_REQ = 0x25, * currently reserved for protocol D */
+ /* P_CKPT_DISABLE_REQ = 0x26, * currently reserved for protocol D */
+ P_DELAY_PROBE = 0x27, /* is used on BOTH sockets */
+ P_OUT_OF_SYNC = 0x28, /* Mark as out of sync (Outrunning), data socket */
+ P_RS_CANCEL = 0x29, /* meta: Used to cancel RS_DATA_REQUEST packet by SyncSource */
+ P_CONN_ST_CHG_REQ = 0x2a, /* data sock: Connection wide state request */
+ P_CONN_ST_CHG_REPLY = 0x2b, /* meta sock: Connection side state req reply */
+ P_RETRY_WRITE = 0x2c, /* Protocol C: retry conflicting write request */
+ P_PROTOCOL_UPDATE = 0x2d, /* data sock: is used in established connections */
+
+ P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
+ P_MAX_OPT_CMD = 0x101,
+
+ /* special command ids for handshake */
+
+ P_INITIAL_META = 0xfff1, /* First Packet on the MetaSock */
+ P_INITIAL_DATA = 0xfff2, /* First Packet on the Socket */
+
+ P_CONNECTION_FEATURES = 0xfffe /* FIXED for the next century! */
+};
+
+#ifndef __packed
+#define __packed __attribute__((packed))
+#endif
+
+/* This is the layout for a packet on the wire.
+ * The byteorder is the network byte order.
+ * (except block_id and barrier fields.
+ * these are pointers to local structs
+ * and have no relevance for the partner,
+ * which just echoes them as received.)
+ *
+ * NOTE that the payload starts at a long aligned offset,
+ * regardless of 32 or 64 bit arch!
+ */
+struct p_header80 {
+ u32 magic;
+ u16 command;
+ u16 length; /* bytes of data after this header */
+} __packed;
+
+/* Header for big packets, Used for data packets exceeding 64kB */
+struct p_header95 {
+ u16 magic; /* use DRBD_MAGIC_BIG here */
+ u16 command;
+ u32 length;
+} __packed;
+
+struct p_header100 {
+ u32 magic;
+ u16 volume;
+ u16 command;
+ u32 length;
+ u32 pad;
+} __packed;
+
+/* these defines must not be changed without changing the protocol version */
+#define DP_HARDBARRIER 1 /* depricated */
+#define DP_RW_SYNC 2 /* equals REQ_SYNC */
+#define DP_MAY_SET_IN_SYNC 4
+#define DP_UNPLUG 8 /* not used anymore */
+#define DP_FUA 16 /* equals REQ_FUA */
+#define DP_FLUSH 32 /* equals REQ_FLUSH */
+#define DP_DISCARD 64 /* equals REQ_DISCARD */
+#define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */
+#define DP_SEND_WRITE_ACK 256 /* This is a proto C write request */
+
+struct p_data {
+ u64 sector; /* 64 bits sector number */
+ u64 block_id; /* to identify the request in protocol B&C */
+ u32 seq_num;
+ u32 dp_flags;
+} __packed;
+
+/*
+ * commands which share a struct:
+ * p_block_ack:
+ * P_RECV_ACK (proto B), P_WRITE_ACK (proto C),
+ * P_SUPERSEDED (proto C, two-primaries conflict detection)
+ * p_block_req:
+ * P_DATA_REQUEST, P_RS_DATA_REQUEST
+ */
+struct p_block_ack {
+ u64 sector;
+ u64 block_id;
+ u32 blksize;
+ u32 seq_num;
+} __packed;
+
+struct p_block_req {
+ u64 sector;
+ u64 block_id;
+ u32 blksize;
+ u32 pad; /* to multiple of 8 Byte */
+} __packed;
+
+/*
+ * commands with their own struct for additional fields:
+ * P_CONNECTION_FEATURES
+ * P_BARRIER
+ * P_BARRIER_ACK
+ * P_SYNC_PARAM
+ * ReportParams
+ */
+
+struct p_connection_features {
+ u32 protocol_min;
+ u32 feature_flags;
+ u32 protocol_max;
+
+ /* should be more than enough for future enhancements
+ * for now, feature_flags and the reserved array shall be zero.
+ */
+
+ u32 _pad;
+ u64 reserved[7];
+} __packed;
+
+struct p_barrier {
+ u32 barrier; /* barrier number _handle_ only */
+ u32 pad; /* to multiple of 8 Byte */
+} __packed;
+
+struct p_barrier_ack {
+ u32 barrier;
+ u32 set_size;
+} __packed;
+
+struct p_rs_param {
+ u32 resync_rate;
+
+ /* Since protocol version 88 and higher. */
+ char verify_alg[0];
+} __packed;
+
+struct p_rs_param_89 {
+ u32 resync_rate;
+ /* protocol version 89: */
+ char verify_alg[SHARED_SECRET_MAX];
+ char csums_alg[SHARED_SECRET_MAX];
+} __packed;
+
+struct p_rs_param_95 {
+ u32 resync_rate;
+ char verify_alg[SHARED_SECRET_MAX];
+ char csums_alg[SHARED_SECRET_MAX];
+ u32 c_plan_ahead;
+ u32 c_delay_target;
+ u32 c_fill_target;
+ u32 c_max_rate;
+} __packed;
+
+enum drbd_conn_flags {
+ CF_DISCARD_MY_DATA = 1,
+ CF_DRY_RUN = 2,
+};
+
+struct p_protocol {
+ u32 protocol;
+ u32 after_sb_0p;
+ u32 after_sb_1p;
+ u32 after_sb_2p;
+ u32 conn_flags;
+ u32 two_primaries;
+
+ /* Since protocol version 87 and higher. */
+ char integrity_alg[0];
+
+} __packed;
+
+struct p_uuids {
+ u64 uuid[UI_EXTENDED_SIZE];
+} __packed;
+
+struct p_rs_uuid {
+ u64 uuid;
+} __packed;
+
+struct p_sizes {
+ u64 d_size; /* size of disk */
+ u64 u_size; /* user requested size */
+ u64 c_size; /* current exported size */
+ u32 max_bio_size; /* Maximal size of a BIO */
+ u16 queue_order_type; /* not yet implemented in DRBD*/
+ u16 dds_flags; /* use enum dds_flags here. */
+} __packed;
+
+struct p_state {
+ u32 state;
+} __packed;
+
+struct p_req_state {
+ u32 mask;
+ u32 val;
+} __packed;
+
+struct p_req_state_reply {
+ u32 retcode;
+} __packed;
+
+struct p_drbd06_param {
+ u64 size;
+ u32 state;
+ u32 blksize;
+ u32 protocol;
+ u32 version;
+ u32 gen_cnt[5];
+ u32 bit_map_gen[5];
+} __packed;
+
+struct p_block_desc {
+ u64 sector;
+ u32 blksize;
+ u32 pad; /* to multiple of 8 Byte */
+} __packed;
+
+/* Valid values for the encoding field.
+ * Bump proto version when changing this. */
+enum drbd_bitmap_code {
+ /* RLE_VLI_Bytes = 0,
+ * and other bit variants had been defined during
+ * algorithm evaluation. */
+ RLE_VLI_Bits = 2,
+};
+
+struct p_compressed_bm {
+ /* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code
+ * (encoding & 0x80): polarity (set/unset) of first runlength
+ * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits
+ * used to pad up to head.length bytes
+ */
+ u8 encoding;
+
+ u8 code[0];
+} __packed;
+
+struct p_delay_probe93 {
+ u32 seq_num; /* sequence number to match the two probe packets */
+ u32 offset; /* usecs the probe got sent after the reference time point */
+} __packed;
+
+/*
+ * Bitmap packets need to fit within a single page on the sender and receiver,
+ * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
+ */
+#define DRBD_SOCKET_BUFFER_SIZE 4096
+
+#endif /* __DRBD_PROTOCOL_H */
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index a861648..bd515e7 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -44,6 +44,7 @@
#include <linux/string.h>
#include <linux/scatterlist.h>
#include "drbd_int.h"
+#include "drbd_protocol.h"
#include "drbd_req.h"
#include "drbd_vli.h"
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 120e1c0..f70dbe2 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -27,6 +27,7 @@
#include <linux/drbd_limits.h>
#include "drbd_int.h"
+#include "drbd_protocol.h"
#include "drbd_req.h"
struct after_state_chg_work {
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 62ff926..35896605 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -36,6 +36,7 @@
#include <linux/scatterlist.h>
#include "drbd_int.h"
+#include "drbd_protocol.h"
#include "drbd_req.h"
static int w_make_ov_request(struct drbd_work *w, int cancel);