1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright (C) 2017 Intel Corporation.
3 * All rights reserved.
4 */
5
6 #include "spdk/string.h"
7 #include "spdk/env.h"
8 #include "spdk/rpc.h"
9 #include "spdk/util.h"
10
11 #include <linux/nbd.h>
12
13 #include "nbd_internal.h"
14 #include "spdk/log.h"
15
16 struct rpc_nbd_start_disk {
17 char *bdev_name;
18 char *nbd_device;
19 /* Used to search one available nbd device */
20 int nbd_idx;
21 bool nbd_idx_specified;
22 struct spdk_jsonrpc_request *request;
23 };
24
25 static void
free_rpc_nbd_start_disk(struct rpc_nbd_start_disk * req)26 free_rpc_nbd_start_disk(struct rpc_nbd_start_disk *req)
27 {
28 free(req->bdev_name);
29 free(req->nbd_device);
30 free(req);
31 }
32
33 static const struct spdk_json_object_decoder rpc_nbd_start_disk_decoders[] = {
34 {"bdev_name", offsetof(struct rpc_nbd_start_disk, bdev_name), spdk_json_decode_string},
35 {"nbd_device", offsetof(struct rpc_nbd_start_disk, nbd_device), spdk_json_decode_string, true},
36 };
37
38 /* Return 0 to indicate the nbd_device might be available,
39 * or non-zero to indicate the nbd_device is invalid or in use.
40 */
41 static int
check_available_nbd_disk(char * nbd_device)42 check_available_nbd_disk(char *nbd_device)
43 {
44 char nbd_block_path[256];
45 char tail[2];
46 int rc;
47 unsigned int nbd_idx;
48 struct spdk_nbd_disk *nbd;
49
50 /* nbd device path must be in format of /dev/nbd<num>, with no tail. */
51 rc = sscanf(nbd_device, "/dev/nbd%u%1s", &nbd_idx, tail);
52 if (rc != 1) {
53 return -errno;
54 }
55
56 /* make sure nbd_device is not registered inside SPDK */
57 nbd = nbd_disk_find_by_nbd_path(nbd_device);
58 if (nbd) {
59 /* nbd_device is in use */
60 return -EBUSY;
61 }
62
63 /* A valid pid file in /sys/block indicates the device is in use */
64 snprintf(nbd_block_path, 256, "/sys/block/nbd%u/pid", nbd_idx);
65
66 rc = open(nbd_block_path, O_RDONLY);
67 if (rc < 0) {
68 if (errno == ENOENT) {
69 /* nbd_device might be available */
70 return 0;
71 } else {
72 SPDK_ERRLOG("Failed to check PID file %s: %s\n", nbd_block_path, spdk_strerror(errno));
73 return -errno;
74 }
75 }
76
77 close(rc);
78
79 /* nbd_device is in use */
80 return -EBUSY;
81 }
82
83 static char *
find_available_nbd_disk(int nbd_idx,int * next_nbd_idx)84 find_available_nbd_disk(int nbd_idx, int *next_nbd_idx)
85 {
86 int i, rc;
87 char nbd_device[20];
88
89 for (i = nbd_idx; ; i++) {
90 snprintf(nbd_device, 20, "/dev/nbd%d", i);
91 /* Check whether an nbd device exists in order to reach the last one nbd device */
92 rc = access(nbd_device, F_OK);
93 if (rc != 0) {
94 break;
95 }
96
97 rc = check_available_nbd_disk(nbd_device);
98 if (rc == 0) {
99 if (next_nbd_idx != NULL) {
100 *next_nbd_idx = i + 1;
101 }
102
103 return strdup(nbd_device);
104 }
105 }
106
107 return NULL;
108 }
109
110 static void
rpc_start_nbd_done(void * cb_arg,struct spdk_nbd_disk * nbd,int rc)111 rpc_start_nbd_done(void *cb_arg, struct spdk_nbd_disk *nbd, int rc)
112 {
113 struct rpc_nbd_start_disk *req = cb_arg;
114 struct spdk_jsonrpc_request *request = req->request;
115 struct spdk_json_write_ctx *w;
116
117 /* Check whether it's automatic nbd-device assignment */
118 if (rc == -EBUSY && req->nbd_idx_specified == false) {
119 free(req->nbd_device);
120
121 req->nbd_device = find_available_nbd_disk(req->nbd_idx, &req->nbd_idx);
122 if (req->nbd_device != NULL) {
123 spdk_nbd_start(req->bdev_name, req->nbd_device,
124 rpc_start_nbd_done, req);
125 return;
126 }
127
128 SPDK_INFOLOG(nbd, "There is no available nbd device.\n");
129 }
130
131 if (rc) {
132 spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
133 free_rpc_nbd_start_disk(req);
134 return;
135 }
136
137 w = spdk_jsonrpc_begin_result(request);
138 spdk_json_write_string(w, spdk_nbd_get_path(nbd));
139 spdk_jsonrpc_end_result(request, w);
140
141 free_rpc_nbd_start_disk(req);
142 }
143
144 static void
rpc_nbd_start_disk(struct spdk_jsonrpc_request * request,const struct spdk_json_val * params)145 rpc_nbd_start_disk(struct spdk_jsonrpc_request *request,
146 const struct spdk_json_val *params)
147 {
148 struct rpc_nbd_start_disk *req;
149 int rc;
150
151 req = calloc(1, sizeof(*req));
152 if (req == NULL) {
153 SPDK_ERRLOG("could not allocate nbd_start_disk request.\n");
154 spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, "Out of memory");
155 return;
156 }
157
158 if (spdk_json_decode_object(params, rpc_nbd_start_disk_decoders,
159 SPDK_COUNTOF(rpc_nbd_start_disk_decoders),
160 req)) {
161 SPDK_ERRLOG("spdk_json_decode_object failed\n");
162 spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
163 "spdk_json_decode_object failed");
164 goto invalid;
165 }
166
167 if (req->bdev_name == NULL) {
168 goto invalid;
169 }
170
171 if (req->nbd_device != NULL) {
172 req->nbd_idx_specified = true;
173 rc = check_available_nbd_disk(req->nbd_device);
174 if (rc == -EBUSY) {
175 SPDK_DEBUGLOG(nbd, "NBD device %s is in use.\n", req->nbd_device);
176 spdk_jsonrpc_send_error_response(request, -EBUSY, spdk_strerror(-rc));
177 goto invalid;
178 }
179
180 if (rc != 0) {
181 SPDK_DEBUGLOG(nbd, "Illegal nbd_device %s.\n", req->nbd_device);
182 spdk_jsonrpc_send_error_response_fmt(request, -ENODEV,
183 "illegal nbd device %s", req->nbd_device);
184 goto invalid;
185 }
186 } else {
187 req->nbd_idx = 0;
188 req->nbd_device = find_available_nbd_disk(req->nbd_idx, &req->nbd_idx);
189 if (req->nbd_device == NULL) {
190 SPDK_INFOLOG(nbd, "There is no available nbd device.\n");
191 spdk_jsonrpc_send_error_response(request, -ENODEV,
192 "nbd device not found");
193 goto invalid;
194 }
195 }
196
197 req->request = request;
198 spdk_nbd_start(req->bdev_name, req->nbd_device,
199 rpc_start_nbd_done, req);
200
201 return;
202
203 invalid:
204 free_rpc_nbd_start_disk(req);
205 }
206
207 SPDK_RPC_REGISTER("nbd_start_disk", rpc_nbd_start_disk, SPDK_RPC_RUNTIME)
208
209 struct rpc_nbd_stop_disk {
210 char *nbd_device;
211 };
212
213 static void
free_rpc_nbd_stop_disk(struct rpc_nbd_stop_disk * req)214 free_rpc_nbd_stop_disk(struct rpc_nbd_stop_disk *req)
215 {
216 free(req->nbd_device);
217 }
218
219 static const struct spdk_json_object_decoder rpc_nbd_stop_disk_decoders[] = {
220 {"nbd_device", offsetof(struct rpc_nbd_stop_disk, nbd_device), spdk_json_decode_string},
221 };
222
223 struct nbd_disconnect_arg {
224 struct spdk_jsonrpc_request *request;
225 struct spdk_nbd_disk *nbd;
226 };
227
228 static void *
nbd_disconnect_thread(void * arg)229 nbd_disconnect_thread(void *arg)
230 {
231 struct nbd_disconnect_arg *thd_arg = arg;
232
233 spdk_unaffinitize_thread();
234
235 nbd_disconnect(thd_arg->nbd);
236
237 spdk_jsonrpc_send_bool_response(thd_arg->request, true);
238
239 free(thd_arg);
240 pthread_exit(NULL);
241 }
242
243 static void
rpc_nbd_stop_disk(struct spdk_jsonrpc_request * request,const struct spdk_json_val * params)244 rpc_nbd_stop_disk(struct spdk_jsonrpc_request *request,
245 const struct spdk_json_val *params)
246 {
247 struct rpc_nbd_stop_disk req = {};
248 struct spdk_nbd_disk *nbd;
249 pthread_t tid;
250 struct nbd_disconnect_arg *thd_arg = NULL;
251 int rc;
252
253 if (spdk_json_decode_object(params, rpc_nbd_stop_disk_decoders,
254 SPDK_COUNTOF(rpc_nbd_stop_disk_decoders),
255 &req)) {
256 SPDK_ERRLOG("spdk_json_decode_object failed\n");
257 spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
258 "spdk_json_decode_object failed");
259 goto out;
260 }
261
262 if (req.nbd_device == NULL) {
263 spdk_jsonrpc_send_error_response(request, -ENODEV, "invalid nbd device");
264 goto out;
265 }
266
267 /* make sure nbd_device is registered */
268 nbd = nbd_disk_find_by_nbd_path(req.nbd_device);
269 if (!nbd) {
270 spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
271 goto out;
272 }
273
274 /*
275 * thd_arg should be freed by created thread
276 * if thread is created successfully.
277 */
278 thd_arg = malloc(sizeof(*thd_arg));
279 if (!thd_arg) {
280 SPDK_ERRLOG("could not allocate nbd disconnect thread arg\n");
281 spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, "Out of memory");
282 goto out;
283 }
284
285 thd_arg->request = request;
286 thd_arg->nbd = nbd;
287
288 /*
289 * NBD ioctl of disconnect will block until data are flushed.
290 * Create separate thread to execute it.
291 */
292 rc = pthread_create(&tid, NULL, nbd_disconnect_thread, (void *)thd_arg);
293 if (rc != 0) {
294 SPDK_ERRLOG("could not create nbd disconnect thread: %s\n", spdk_strerror(rc));
295 spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, spdk_strerror(rc));
296 free(thd_arg);
297 goto out;
298 }
299
300 rc = pthread_detach(tid);
301 if (rc != 0) {
302 SPDK_ERRLOG("could not detach nbd disconnect thread: %s\n", spdk_strerror(rc));
303 goto out;
304 }
305
306 out:
307 free_rpc_nbd_stop_disk(&req);
308 }
309
310 SPDK_RPC_REGISTER("nbd_stop_disk", rpc_nbd_stop_disk, SPDK_RPC_RUNTIME)
311
312 static void
rpc_dump_nbd_info(struct spdk_json_write_ctx * w,struct spdk_nbd_disk * nbd)313 rpc_dump_nbd_info(struct spdk_json_write_ctx *w,
314 struct spdk_nbd_disk *nbd)
315 {
316 spdk_json_write_object_begin(w);
317
318 spdk_json_write_named_string(w, "nbd_device", nbd_disk_get_nbd_path(nbd));
319
320 spdk_json_write_named_string(w, "bdev_name", nbd_disk_get_bdev_name(nbd));
321
322 spdk_json_write_object_end(w);
323 }
324
325 struct rpc_nbd_get_disks {
326 char *nbd_device;
327 };
328
329 static void
free_rpc_nbd_get_disks(struct rpc_nbd_get_disks * r)330 free_rpc_nbd_get_disks(struct rpc_nbd_get_disks *r)
331 {
332 free(r->nbd_device);
333 }
334
335 static const struct spdk_json_object_decoder rpc_nbd_get_disks_decoders[] = {
336 {"nbd_device", offsetof(struct rpc_nbd_get_disks, nbd_device), spdk_json_decode_string, true},
337 };
338
339 static void
rpc_nbd_get_disks(struct spdk_jsonrpc_request * request,const struct spdk_json_val * params)340 rpc_nbd_get_disks(struct spdk_jsonrpc_request *request,
341 const struct spdk_json_val *params)
342 {
343 struct rpc_nbd_get_disks req = {};
344 struct spdk_json_write_ctx *w;
345 struct spdk_nbd_disk *nbd = NULL;
346
347 if (params != NULL) {
348 if (spdk_json_decode_object(params, rpc_nbd_get_disks_decoders,
349 SPDK_COUNTOF(rpc_nbd_get_disks_decoders),
350 &req)) {
351 SPDK_ERRLOG("spdk_json_decode_object failed\n");
352 spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
353 "spdk_json_decode_object failed");
354 goto invalid;
355 }
356
357 if (req.nbd_device) {
358 nbd = nbd_disk_find_by_nbd_path(req.nbd_device);
359 if (nbd == NULL) {
360 SPDK_ERRLOG("nbd device '%s' does not exist\n", req.nbd_device);
361 spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
362 goto invalid;
363 }
364
365 free_rpc_nbd_get_disks(&req);
366 }
367 }
368
369 w = spdk_jsonrpc_begin_result(request);
370 spdk_json_write_array_begin(w);
371
372 if (nbd != NULL) {
373 rpc_dump_nbd_info(w, nbd);
374 } else {
375 for (nbd = nbd_disk_first(); nbd != NULL; nbd = nbd_disk_next(nbd)) {
376 rpc_dump_nbd_info(w, nbd);
377 }
378 }
379
380 spdk_json_write_array_end(w);
381
382 spdk_jsonrpc_end_result(request, w);
383
384 return;
385
386 invalid:
387 free_rpc_nbd_get_disks(&req);
388 }
389 SPDK_RPC_REGISTER("nbd_get_disks", rpc_nbd_get_disks, SPDK_RPC_RUNTIME)
390