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 2
22
23 /* The default port number the RTRS server is listening on. */
24 #define RTRS_PORT 1234
25
26 /**
27 * enum rnbd_msg_type - 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 /* private: */
51 __le16 __padding;
52 };
53
54 /*
55 * We allow to map RO many times and RW only once. We allow to map yet another
56 * time RW, if MIGRATION is provided (second RW export can be required for
57 * example for VM migration)
58 */
59 enum rnbd_access_mode {
60 RNBD_ACCESS_RO,
61 RNBD_ACCESS_RW,
62 RNBD_ACCESS_MIGRATION,
63 };
64
65 static const __maybe_unused struct {
66 enum rnbd_access_mode mode;
67 const char *str;
68 } rnbd_access_modes[] = {
69 [RNBD_ACCESS_RO] = {RNBD_ACCESS_RO, "ro"},
70 [RNBD_ACCESS_RW] = {RNBD_ACCESS_RW, "rw"},
71 [RNBD_ACCESS_MIGRATION] = {RNBD_ACCESS_MIGRATION, "migration"},
72 };
73
74 /**
75 * struct rnbd_msg_sess_info - initial session info from client to server
76 * @hdr: message header
77 * @ver: RNBD protocol version
78 */
79 struct rnbd_msg_sess_info {
80 struct rnbd_msg_hdr hdr;
81 u8 ver;
82 /* private: */
83 u8 reserved[31];
84 };
85
86 /**
87 * struct rnbd_msg_sess_info_rsp - initial session info from server to client
88 * @hdr: message header
89 * @ver: RNBD protocol version
90 */
91 struct rnbd_msg_sess_info_rsp {
92 struct rnbd_msg_hdr hdr;
93 u8 ver;
94 /* private: */
95 u8 reserved[31];
96 };
97
98 /**
99 * struct rnbd_msg_open - request to open a remote device.
100 * @hdr: message header
101 * @access_mode: the mode to open remote device, valid values see:
102 * enum rnbd_access_mode
103 * @dev_name: device path on remote side
104 */
105 struct rnbd_msg_open {
106 struct rnbd_msg_hdr hdr;
107 u8 access_mode;
108 /* private: */
109 u8 resv1;
110 /* public: */
111 s8 dev_name[NAME_MAX];
112 /* private: */
113 u8 reserved[3];
114 };
115
116 /**
117 * struct rnbd_msg_close - request to close a remote device.
118 * @hdr: message header
119 * @device_id: device_id on server side to identify the device
120 */
121 struct rnbd_msg_close {
122 struct rnbd_msg_hdr hdr;
123 __le32 device_id;
124 };
125
126 enum rnbd_cache_policy {
127 RNBD_FUA = 1 << 0,
128 RNBD_WRITEBACK = 1 << 1,
129 };
130
131 /**
132 * struct rnbd_msg_open_rsp - response message to RNBD_MSG_OPEN
133 * @hdr: message header
134 * @device_id: device_id on server side to identify the device
135 * @nsectors: number of sectors in the usual 512b unit
136 * @max_hw_sectors: max hardware sectors in the usual 512b unit
137 * @max_write_zeroes_sectors: max sectors for WRITE ZEROES in the 512b unit
138 * @max_discard_sectors: max. sectors that can be discarded at once in 512b
139 * unit.
140 * @discard_granularity: size of the internal discard allocation unit in bytes
141 * @discard_alignment: offset from internal allocation assignment in bytes
142 * @physical_block_size: physical block size device supports in bytes
143 * @logical_block_size: logical block size device supports in bytes
144 * @max_segments: max segments hardware support in one transfer
145 * @secure_discard: supports secure discard
146 * @obsolete_rotational: obsolete, not in used.
147 * @cache_policy: support write-back caching or FUA?
148 */
149 struct rnbd_msg_open_rsp {
150 struct rnbd_msg_hdr hdr;
151 __le32 device_id;
152 __le64 nsectors;
153 __le32 max_hw_sectors;
154 __le32 max_write_zeroes_sectors;
155 __le32 max_discard_sectors;
156 __le32 discard_granularity;
157 __le32 discard_alignment;
158 __le16 physical_block_size;
159 __le16 logical_block_size;
160 __le16 max_segments;
161 __le16 secure_discard;
162 u8 obsolete_rotational;
163 u8 cache_policy;
164 /* private: */
165 u8 reserved[10];
166 };
167
168 /**
169 * struct rnbd_msg_io - message for I/O read/write
170 * @hdr: message header
171 * @device_id: device_id on server side to find the right device
172 * @sector: bi_sector attribute from struct bio
173 * @rw: valid values are defined in enum rnbd_io_flags
174 * @bi_size: number of bytes for I/O read/write
175 * @prio: priority
176 */
177 struct rnbd_msg_io {
178 struct rnbd_msg_hdr hdr;
179 __le32 device_id;
180 __le64 sector;
181 __le32 rw;
182 __le32 bi_size;
183 __le16 prio;
184 };
185
186 #define RNBD_OP_BITS 8
187 #define RNBD_OP_MASK ((1 << RNBD_OP_BITS) - 1)
188
189 /**
190 * enum rnbd_io_flags - RNBD request types from rq_flag_bits
191 * @RNBD_OP_READ: read sectors from the device
192 * @RNBD_OP_WRITE: write sectors to the device
193 * @RNBD_OP_FLUSH: flush the volatile write cache
194 * @RNBD_OP_DISCARD: discard sectors
195 * @RNBD_OP_SECURE_ERASE: securely erase sectors
196 * @RNBD_OP_WRITE_ZEROES: write zeroes sectors
197 *
198 * @RNBD_F_SYNC: request is sync (sync write or read)
199 * @RNBD_F_FUA: forced unit access
200 * @RNBD_F_PREFLUSH: request for cache flush
201 * @RNBD_F_NOUNMAP: do not free blocks when zeroing
202 */
203 enum rnbd_io_flags {
204
205 /* Operations */
206 RNBD_OP_READ = 0,
207 RNBD_OP_WRITE = 1,
208 RNBD_OP_FLUSH = 2,
209 RNBD_OP_DISCARD = 3,
210 RNBD_OP_SECURE_ERASE = 4,
211 RNBD_OP_WRITE_ZEROES = 5,
212
213 /* Flags */
214 RNBD_F_SYNC = 1<<(RNBD_OP_BITS + 0),
215 RNBD_F_FUA = 1<<(RNBD_OP_BITS + 1),
216 RNBD_F_PREFLUSH = 1<<(RNBD_OP_BITS + 2),
217 RNBD_F_NOUNMAP = 1<<(RNBD_OP_BITS + 3)
218 };
219
rnbd_op(u32 flags)220 static inline u32 rnbd_op(u32 flags)
221 {
222 return flags & RNBD_OP_MASK;
223 }
224
rnbd_flags(u32 flags)225 static inline u32 rnbd_flags(u32 flags)
226 {
227 return flags & ~RNBD_OP_MASK;
228 }
229
rnbd_to_bio_flags(u32 rnbd_opf)230 static inline blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf)
231 {
232 blk_opf_t bio_opf;
233
234 switch (rnbd_op(rnbd_opf)) {
235 case RNBD_OP_READ:
236 bio_opf = REQ_OP_READ;
237 break;
238 case RNBD_OP_WRITE:
239 bio_opf = REQ_OP_WRITE;
240 break;
241 case RNBD_OP_FLUSH:
242 bio_opf = REQ_OP_WRITE | REQ_PREFLUSH;
243 break;
244 case RNBD_OP_DISCARD:
245 bio_opf = REQ_OP_DISCARD;
246 break;
247 case RNBD_OP_SECURE_ERASE:
248 bio_opf = REQ_OP_SECURE_ERASE;
249 break;
250 case RNBD_OP_WRITE_ZEROES:
251 bio_opf = REQ_OP_WRITE_ZEROES;
252
253 if (rnbd_opf & RNBD_F_NOUNMAP)
254 bio_opf |= REQ_NOUNMAP;
255 break;
256 default:
257 WARN(1, "Unknown RNBD type: %d (flags %d)\n",
258 rnbd_op(rnbd_opf), rnbd_opf);
259 bio_opf = 0;
260 }
261
262 if (rnbd_opf & RNBD_F_SYNC)
263 bio_opf |= REQ_SYNC;
264
265 if (rnbd_opf & RNBD_F_FUA)
266 bio_opf |= REQ_FUA;
267
268 if (rnbd_opf & RNBD_F_PREFLUSH)
269 bio_opf |= REQ_PREFLUSH;
270
271 return bio_opf;
272 }
273
rq_to_rnbd_flags(struct request * rq)274 static inline u32 rq_to_rnbd_flags(struct request *rq)
275 {
276 u32 rnbd_opf;
277
278 switch (req_op(rq)) {
279 case REQ_OP_READ:
280 rnbd_opf = RNBD_OP_READ;
281 break;
282 case REQ_OP_WRITE:
283 rnbd_opf = RNBD_OP_WRITE;
284 break;
285 case REQ_OP_DISCARD:
286 rnbd_opf = RNBD_OP_DISCARD;
287 break;
288 case REQ_OP_SECURE_ERASE:
289 rnbd_opf = RNBD_OP_SECURE_ERASE;
290 break;
291 case REQ_OP_WRITE_ZEROES:
292 rnbd_opf = RNBD_OP_WRITE_ZEROES;
293
294 if (rq->cmd_flags & REQ_NOUNMAP)
295 rnbd_opf |= RNBD_F_NOUNMAP;
296 break;
297 case REQ_OP_FLUSH:
298 rnbd_opf = RNBD_OP_FLUSH;
299 break;
300 default:
301 WARN(1, "Unknown request type %d (flags %llu)\n",
302 (__force u32)req_op(rq),
303 (__force unsigned long long)rq->cmd_flags);
304 rnbd_opf = 0;
305 }
306
307 if (op_is_sync(rq->cmd_flags))
308 rnbd_opf |= RNBD_F_SYNC;
309
310 if (op_is_flush(rq->cmd_flags))
311 rnbd_opf |= RNBD_F_FUA;
312
313 if (rq->cmd_flags & REQ_PREFLUSH)
314 rnbd_opf |= RNBD_F_PREFLUSH;
315
316 return rnbd_opf;
317 }
318
319 const char *rnbd_access_mode_str(enum rnbd_access_mode mode);
320
321 #endif /* RNBD_PROTO_H */
322