1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * RDMA Network Block Driver 4 * 5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved. 6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved. 7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved. 8 */ 9 #ifndef RNBD_PROTO_H 10 #define RNBD_PROTO_H 11 12 #include <linux/types.h> 13 #include <linux/blk-mq.h> 14 #include <linux/limits.h> 15 #include <linux/inet.h> 16 #include <linux/in.h> 17 #include <linux/in6.h> 18 #include <rdma/ib.h> 19 20 #define RNBD_PROTO_VER_MAJOR 2 21 #define RNBD_PROTO_VER_MINOR 0 22 23 /* The default port number the RTRS server is listening on. */ 24 #define RTRS_PORT 1234 25 26 /** 27 * enum rnbd_msg_types - RNBD message types 28 * @RNBD_MSG_SESS_INFO: initial session info from client to server 29 * @RNBD_MSG_SESS_INFO_RSP: initial session info from server to client 30 * @RNBD_MSG_OPEN: open (map) device request 31 * @RNBD_MSG_OPEN_RSP: response to an @RNBD_MSG_OPEN 32 * @RNBD_MSG_IO: block IO request operation 33 * @RNBD_MSG_CLOSE: close (unmap) device request 34 */ 35 enum rnbd_msg_type { 36 RNBD_MSG_SESS_INFO, 37 RNBD_MSG_SESS_INFO_RSP, 38 RNBD_MSG_OPEN, 39 RNBD_MSG_OPEN_RSP, 40 RNBD_MSG_IO, 41 RNBD_MSG_CLOSE, 42 }; 43 44 /** 45 * struct rnbd_msg_hdr - header of RNBD messages 46 * @type: Message type, valid values see: enum rnbd_msg_types 47 */ 48 struct rnbd_msg_hdr { 49 __le16 type; 50 __le16 __padding; 51 }; 52 53 /** 54 * We allow to map RO many times and RW only once. We allow to map yet another 55 * time RW, if MIGRATION is provided (second RW export can be required for 56 * example for VM migration) 57 */ 58 enum rnbd_access_mode { 59 RNBD_ACCESS_RO, 60 RNBD_ACCESS_RW, 61 RNBD_ACCESS_MIGRATION, 62 }; 63 64 static const __maybe_unused struct { 65 enum rnbd_access_mode mode; 66 const char *str; 67 } rnbd_access_modes[] = { 68 [RNBD_ACCESS_RO] = {RNBD_ACCESS_RO, "ro"}, 69 [RNBD_ACCESS_RW] = {RNBD_ACCESS_RW, "rw"}, 70 [RNBD_ACCESS_MIGRATION] = {RNBD_ACCESS_MIGRATION, "migration"}, 71 }; 72 73 /** 74 * struct rnbd_msg_sess_info - initial session info from client to server 75 * @hdr: message header 76 * @ver: RNBD protocol version 77 */ 78 struct rnbd_msg_sess_info { 79 struct rnbd_msg_hdr hdr; 80 u8 ver; 81 u8 reserved[31]; 82 }; 83 84 /** 85 * struct rnbd_msg_sess_info_rsp - initial session info from server to client 86 * @hdr: message header 87 * @ver: RNBD protocol version 88 */ 89 struct rnbd_msg_sess_info_rsp { 90 struct rnbd_msg_hdr hdr; 91 u8 ver; 92 u8 reserved[31]; 93 }; 94 95 /** 96 * struct rnbd_msg_open - request to open a remote device. 97 * @hdr: message header 98 * @access_mode: the mode to open remote device, valid values see: 99 * enum rnbd_access_mode 100 * @device_name: device path on remote side 101 */ 102 struct rnbd_msg_open { 103 struct rnbd_msg_hdr hdr; 104 u8 access_mode; 105 u8 resv1; 106 s8 dev_name[NAME_MAX]; 107 u8 reserved[3]; 108 }; 109 110 /** 111 * struct rnbd_msg_close - request to close a remote device. 112 * @hdr: message header 113 * @device_id: device_id on server side to identify the device 114 */ 115 struct rnbd_msg_close { 116 struct rnbd_msg_hdr hdr; 117 __le32 device_id; 118 }; 119 120 enum rnbd_cache_policy { 121 RNBD_FUA = 1 << 0, 122 RNBD_WRITEBACK = 1 << 1, 123 }; 124 125 /** 126 * struct rnbd_msg_open_rsp - response message to RNBD_MSG_OPEN 127 * @hdr: message header 128 * @device_id: device_id on server side to identify the device 129 * @nsectors: number of sectors in the usual 512b unit 130 * @max_hw_sectors: max hardware sectors in the usual 512b unit 131 * @max_write_zeroes_sectors: max sectors for WRITE ZEROES in the 512b unit 132 * @max_discard_sectors: max. sectors that can be discarded at once in 512b 133 * unit. 134 * @discard_granularity: size of the internal discard allocation unit in bytes 135 * @discard_alignment: offset from internal allocation assignment in bytes 136 * @physical_block_size: physical block size device supports in bytes 137 * @logical_block_size: logical block size device supports in bytes 138 * @max_segments: max segments hardware support in one transfer 139 * @secure_discard: supports secure discard 140 * @obsolete_rotational: obsolete, not in used. 141 * @cache_policy: support write-back caching or FUA? 142 */ 143 struct rnbd_msg_open_rsp { 144 struct rnbd_msg_hdr hdr; 145 __le32 device_id; 146 __le64 nsectors; 147 __le32 max_hw_sectors; 148 __le32 max_write_zeroes_sectors; 149 __le32 max_discard_sectors; 150 __le32 discard_granularity; 151 __le32 discard_alignment; 152 __le16 physical_block_size; 153 __le16 logical_block_size; 154 __le16 max_segments; 155 __le16 secure_discard; 156 u8 obsolete_rotational; 157 u8 cache_policy; 158 u8 reserved[10]; 159 }; 160 161 /** 162 * struct rnbd_msg_io - message for I/O read/write 163 * @hdr: message header 164 * @device_id: device_id on server side to find the right device 165 * @sector: bi_sector attribute from struct bio 166 * @rw: valid values are defined in enum rnbd_io_flags 167 * @bi_size: number of bytes for I/O read/write 168 * @prio: priority 169 */ 170 struct rnbd_msg_io { 171 struct rnbd_msg_hdr hdr; 172 __le32 device_id; 173 __le64 sector; 174 __le32 rw; 175 __le32 bi_size; 176 __le16 prio; 177 }; 178 179 #define RNBD_OP_BITS 8 180 #define RNBD_OP_MASK ((1 << RNBD_OP_BITS) - 1) 181 182 /** 183 * enum rnbd_io_flags - RNBD request types from rq_flag_bits 184 * @RNBD_OP_READ: read sectors from the device 185 * @RNBD_OP_WRITE: write sectors to the device 186 * @RNBD_OP_FLUSH: flush the volatile write cache 187 * @RNBD_OP_DISCARD: discard sectors 188 * @RNBD_OP_SECURE_ERASE: securely erase sectors 189 * @RNBD_OP_WRITE_ZEROES: write zeroes sectors 190 191 * @RNBD_F_SYNC: request is sync (sync write or read) 192 * @RNBD_F_FUA: forced unit access 193 */ 194 enum rnbd_io_flags { 195 196 /* Operations */ 197 RNBD_OP_READ = 0, 198 RNBD_OP_WRITE = 1, 199 RNBD_OP_FLUSH = 2, 200 RNBD_OP_DISCARD = 3, 201 RNBD_OP_SECURE_ERASE = 4, 202 RNBD_OP_WRITE_ZEROES = 5, 203 204 /* Flags */ 205 RNBD_F_SYNC = 1<<(RNBD_OP_BITS + 0), 206 RNBD_F_FUA = 1<<(RNBD_OP_BITS + 1), 207 }; 208 209 static inline u32 rnbd_op(u32 flags) 210 { 211 return flags & RNBD_OP_MASK; 212 } 213 214 static inline u32 rnbd_flags(u32 flags) 215 { 216 return flags & ~RNBD_OP_MASK; 217 } 218 219 static inline blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf) 220 { 221 blk_opf_t bio_opf; 222 223 switch (rnbd_op(rnbd_opf)) { 224 case RNBD_OP_READ: 225 bio_opf = REQ_OP_READ; 226 break; 227 case RNBD_OP_WRITE: 228 bio_opf = REQ_OP_WRITE; 229 break; 230 case RNBD_OP_FLUSH: 231 bio_opf = REQ_OP_WRITE | REQ_PREFLUSH; 232 break; 233 case RNBD_OP_DISCARD: 234 bio_opf = REQ_OP_DISCARD; 235 break; 236 case RNBD_OP_SECURE_ERASE: 237 bio_opf = REQ_OP_SECURE_ERASE; 238 break; 239 case RNBD_OP_WRITE_ZEROES: 240 bio_opf = REQ_OP_WRITE_ZEROES; 241 break; 242 default: 243 WARN(1, "Unknown RNBD type: %d (flags %d)\n", 244 rnbd_op(rnbd_opf), rnbd_opf); 245 bio_opf = 0; 246 } 247 248 if (rnbd_opf & RNBD_F_SYNC) 249 bio_opf |= REQ_SYNC; 250 251 if (rnbd_opf & RNBD_F_FUA) 252 bio_opf |= REQ_FUA; 253 254 return bio_opf; 255 } 256 257 static inline u32 rq_to_rnbd_flags(struct request *rq) 258 { 259 u32 rnbd_opf; 260 261 switch (req_op(rq)) { 262 case REQ_OP_READ: 263 rnbd_opf = RNBD_OP_READ; 264 break; 265 case REQ_OP_WRITE: 266 rnbd_opf = RNBD_OP_WRITE; 267 break; 268 case REQ_OP_DISCARD: 269 rnbd_opf = RNBD_OP_DISCARD; 270 break; 271 case REQ_OP_SECURE_ERASE: 272 rnbd_opf = RNBD_OP_SECURE_ERASE; 273 break; 274 case REQ_OP_WRITE_ZEROES: 275 rnbd_opf = RNBD_OP_WRITE_ZEROES; 276 break; 277 case REQ_OP_FLUSH: 278 rnbd_opf = RNBD_OP_FLUSH; 279 break; 280 default: 281 WARN(1, "Unknown request type %d (flags %llu)\n", 282 (__force u32)req_op(rq), 283 (__force unsigned long long)rq->cmd_flags); 284 rnbd_opf = 0; 285 } 286 287 if (op_is_sync(rq->cmd_flags)) 288 rnbd_opf |= RNBD_F_SYNC; 289 290 if (op_is_flush(rq->cmd_flags)) 291 rnbd_opf |= RNBD_F_FUA; 292 293 return rnbd_opf; 294 } 295 296 const char *rnbd_access_mode_str(enum rnbd_access_mode mode); 297 298 #endif /* RNBD_PROTO_H */ 299