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Linux kernel mirror (for testing)
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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_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 */
35enum 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 */
48struct 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 */
59enum rnbd_access_mode {
60 RNBD_ACCESS_RO,
61 RNBD_ACCESS_RW,
62 RNBD_ACCESS_MIGRATION,
63};
64
65static 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 */
79struct 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 */
91struct 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 */
105struct 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 */
121struct rnbd_msg_close {
122 struct rnbd_msg_hdr hdr;
123 __le32 device_id;
124};
125
126enum 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 */
149struct 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 */
177struct 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 */
201enum rnbd_io_flags {
202
203 /* Operations */
204 RNBD_OP_READ = 0,
205 RNBD_OP_WRITE = 1,
206 RNBD_OP_FLUSH = 2,
207 RNBD_OP_DISCARD = 3,
208 RNBD_OP_SECURE_ERASE = 4,
209 RNBD_OP_WRITE_ZEROES = 5,
210
211 /* Flags */
212 RNBD_F_SYNC = 1<<(RNBD_OP_BITS + 0),
213 RNBD_F_FUA = 1<<(RNBD_OP_BITS + 1),
214};
215
216static inline u32 rnbd_op(u32 flags)
217{
218 return flags & RNBD_OP_MASK;
219}
220
221static inline u32 rnbd_flags(u32 flags)
222{
223 return flags & ~RNBD_OP_MASK;
224}
225
226static inline blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf)
227{
228 blk_opf_t bio_opf;
229
230 switch (rnbd_op(rnbd_opf)) {
231 case RNBD_OP_READ:
232 bio_opf = REQ_OP_READ;
233 break;
234 case RNBD_OP_WRITE:
235 bio_opf = REQ_OP_WRITE;
236 break;
237 case RNBD_OP_FLUSH:
238 bio_opf = REQ_OP_WRITE | REQ_PREFLUSH;
239 break;
240 case RNBD_OP_DISCARD:
241 bio_opf = REQ_OP_DISCARD;
242 break;
243 case RNBD_OP_SECURE_ERASE:
244 bio_opf = REQ_OP_SECURE_ERASE;
245 break;
246 case RNBD_OP_WRITE_ZEROES:
247 bio_opf = REQ_OP_WRITE_ZEROES;
248 break;
249 default:
250 WARN(1, "Unknown RNBD type: %d (flags %d)\n",
251 rnbd_op(rnbd_opf), rnbd_opf);
252 bio_opf = 0;
253 }
254
255 if (rnbd_opf & RNBD_F_SYNC)
256 bio_opf |= REQ_SYNC;
257
258 if (rnbd_opf & RNBD_F_FUA)
259 bio_opf |= REQ_FUA;
260
261 return bio_opf;
262}
263
264static inline u32 rq_to_rnbd_flags(struct request *rq)
265{
266 u32 rnbd_opf;
267
268 switch (req_op(rq)) {
269 case REQ_OP_READ:
270 rnbd_opf = RNBD_OP_READ;
271 break;
272 case REQ_OP_WRITE:
273 rnbd_opf = RNBD_OP_WRITE;
274 break;
275 case REQ_OP_DISCARD:
276 rnbd_opf = RNBD_OP_DISCARD;
277 break;
278 case REQ_OP_SECURE_ERASE:
279 rnbd_opf = RNBD_OP_SECURE_ERASE;
280 break;
281 case REQ_OP_WRITE_ZEROES:
282 rnbd_opf = RNBD_OP_WRITE_ZEROES;
283 break;
284 case REQ_OP_FLUSH:
285 rnbd_opf = RNBD_OP_FLUSH;
286 break;
287 default:
288 WARN(1, "Unknown request type %d (flags %llu)\n",
289 (__force u32)req_op(rq),
290 (__force unsigned long long)rq->cmd_flags);
291 rnbd_opf = 0;
292 }
293
294 if (op_is_sync(rq->cmd_flags))
295 rnbd_opf |= RNBD_F_SYNC;
296
297 if (op_is_flush(rq->cmd_flags))
298 rnbd_opf |= RNBD_F_FUA;
299
300 return rnbd_opf;
301}
302
303const char *rnbd_access_mode_str(enum rnbd_access_mode mode);
304
305#endif /* RNBD_PROTO_H */