diff options
Diffstat (limited to 'drivers/block/drbd/drbd_protocol.h')
| -rw-r--r-- | drivers/block/drbd/drbd_protocol.h | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_protocol.h b/drivers/block/drbd/drbd_protocol.h new file mode 100644 index 000000000..2da9104a3 --- /dev/null +++ b/drivers/block/drbd/drbd_protocol.h @@ -0,0 +1,307 @@ +#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 */ + /* 0x2e to 0x30 reserved, used in drbd 9 */ + + /* REQ_DISCARD. We used "discard" in different contexts before, + * which is why I chose TRIM here, to disambiguate. */ + P_TRIM = 0x31, + + 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; + +struct p_trim { + struct p_data p_data; + u32 size; /* == bio->bi_size */ +} __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 + */ + +#define FF_TRIM 1 + +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 */ |