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drbd: Split off on-the-wire protocol definitions
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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>
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Andreas Gruenbacher authored and Philipp Reisner committed Feb 17, 2014
1 parent d81dc4f commit a3603a6
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Showing 7 changed files with 301 additions and 292 deletions.
293 changes: 1 addition & 292 deletions drivers/block/drbd/drbd_int.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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")))
Expand Down Expand Up @@ -168,72 +169,6 @@ extern struct ratelimit_state drbd_ratelimit_state;
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,
Expand Down Expand Up @@ -276,234 +211,8 @@ static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c)
#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,
Expand Down
1 change: 1 addition & 0 deletions drivers/block/drbd/drbd_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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"
Expand Down
1 change: 1 addition & 0 deletions drivers/block/drbd/drbd_nl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down
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