xref: /spdk/lib/nbd/nbd_rpc.c (revision 9889ab2dc80e40dae92dcef361d53dcba722043d)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/string.h"
35 #include "spdk/env.h"
36 #include "spdk/rpc.h"
37 #include "spdk/util.h"
38 
39 #include <linux/nbd.h>
40 
41 #include "nbd_internal.h"
42 #include "spdk_internal/log.h"
43 
44 struct rpc_nbd_start_disk {
45 	char *bdev_name;
46 	char *nbd_device;
47 	/* Used to search one available nbd device */
48 	int nbd_idx;
49 	bool nbd_idx_specified;
50 	struct spdk_jsonrpc_request *request;
51 };
52 
53 static void
54 free_rpc_nbd_start_disk(struct rpc_nbd_start_disk *req)
55 {
56 	free(req->bdev_name);
57 	free(req->nbd_device);
58 	free(req);
59 }
60 
61 static const struct spdk_json_object_decoder rpc_nbd_start_disk_decoders[] = {
62 	{"bdev_name", offsetof(struct rpc_nbd_start_disk, bdev_name), spdk_json_decode_string},
63 	{"nbd_device", offsetof(struct rpc_nbd_start_disk, nbd_device), spdk_json_decode_string, true},
64 };
65 
66 /* Return 0 to indicate the nbd_device might be available,
67  * or non-zero to indicate the nbd_device is invalid or in using.
68  */
69 static int
70 check_available_nbd_disk(char *nbd_device)
71 {
72 	char nbd_block_path[256];
73 	char tail[2];
74 	int rc;
75 	unsigned int nbd_idx;
76 	struct spdk_nbd_disk *nbd;
77 
78 	/* nbd device path must be in format of /dev/nbd<num>, with no tail. */
79 	rc = sscanf(nbd_device, "/dev/nbd%u%1s", &nbd_idx, tail);
80 	if (rc != 1) {
81 		return -errno;
82 	}
83 
84 	/* make sure nbd_device is not registered inside SPDK */
85 	nbd = spdk_nbd_disk_find_by_nbd_path(nbd_device);
86 	if (nbd) {
87 		/* nbd_device is in using */
88 		return -EBUSY;
89 	}
90 
91 	/* A valid pid file in /sys/block indicates the device is in using */
92 	snprintf(nbd_block_path, 256, "/sys/block/nbd%u/pid", nbd_idx);
93 
94 	rc = open(nbd_block_path, O_RDONLY);
95 	if (rc < 0) {
96 		if (errno == ENOENT) {
97 			/* nbd_device might be available */
98 			return 0;
99 		} else {
100 			SPDK_ERRLOG("Failed to check PID file %s: %s\n", nbd_block_path, spdk_strerror(errno));
101 			return -errno;
102 		}
103 	}
104 
105 	close(rc);
106 
107 	/* nbd_device is in using */
108 	return -EBUSY;
109 }
110 
111 static char *
112 find_available_nbd_disk(int nbd_idx, int *next_nbd_idx)
113 {
114 	int i, rc;
115 	char nbd_device[20];
116 
117 	for (i = nbd_idx; ; i++) {
118 		snprintf(nbd_device, 20, "/dev/nbd%d", i);
119 		/* Check whether an nbd device exists in order to reach the last one nbd device */
120 		rc = access(nbd_device, F_OK);
121 		if (rc != 0) {
122 			break;
123 		}
124 
125 		rc = check_available_nbd_disk(nbd_device);
126 		if (rc == 0) {
127 			if (next_nbd_idx != NULL) {
128 				*next_nbd_idx = i + 1;
129 			}
130 
131 			return strdup(nbd_device);
132 		}
133 	}
134 
135 	return NULL;
136 }
137 
138 static void
139 spdk_rpc_start_nbd_done(void *cb_arg, struct spdk_nbd_disk *nbd, int rc)
140 {
141 	struct rpc_nbd_start_disk *req = cb_arg;
142 	struct spdk_jsonrpc_request *request = req->request;
143 	struct spdk_json_write_ctx *w;
144 
145 	/* Check whether it's automatic nbd-device assignment */
146 	if (rc == -EBUSY && req->nbd_idx_specified == false) {
147 		free(req->nbd_device);
148 
149 		req->nbd_device = find_available_nbd_disk(req->nbd_idx, &req->nbd_idx);
150 		if (req->nbd_device != NULL) {
151 			spdk_nbd_start(req->bdev_name, req->nbd_device,
152 				       spdk_rpc_start_nbd_done, req);
153 			return;
154 		}
155 
156 		SPDK_INFOLOG(SPDK_LOG_NBD, "There is no available nbd device.\n");
157 	}
158 
159 	if (rc) {
160 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
161 		return;
162 	}
163 
164 	w = spdk_jsonrpc_begin_result(request);
165 	spdk_json_write_string(w, spdk_nbd_get_path(nbd));
166 	spdk_jsonrpc_end_result(request, w);
167 
168 	free_rpc_nbd_start_disk(req);
169 }
170 
171 static void
172 spdk_rpc_nbd_start_disk(struct spdk_jsonrpc_request *request,
173 			const struct spdk_json_val *params)
174 {
175 	struct rpc_nbd_start_disk *req;
176 	int rc;
177 
178 	req = calloc(1, sizeof(*req));
179 	if (req == NULL) {
180 		SPDK_ERRLOG("could not allocate nbd_start_disk request.\n");
181 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, "Out of memory");
182 		return;
183 	}
184 
185 	if (spdk_json_decode_object(params, rpc_nbd_start_disk_decoders,
186 				    SPDK_COUNTOF(rpc_nbd_start_disk_decoders),
187 				    req)) {
188 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
189 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
190 						 "spdk_json_decode_object failed");
191 		goto invalid;
192 	}
193 
194 	if (req->bdev_name == NULL) {
195 		goto invalid;
196 	}
197 
198 	if (req->nbd_device != NULL) {
199 		req->nbd_idx_specified = true;
200 		rc = check_available_nbd_disk(req->nbd_device);
201 		if (rc == -EBUSY) {
202 			SPDK_DEBUGLOG(SPDK_LOG_NBD, "NBD device %s is in using.\n", req->nbd_device);
203 			spdk_jsonrpc_send_error_response(request, -EBUSY, spdk_strerror(-rc));
204 			goto invalid;
205 		}
206 
207 		if (rc != 0) {
208 			SPDK_DEBUGLOG(SPDK_LOG_NBD, "Illegal nbd_device %s.\n", req->nbd_device);
209 			spdk_jsonrpc_send_error_response_fmt(request, -ENODEV,
210 							     "illegal nbd device %s", req->nbd_device);
211 			goto invalid;
212 		}
213 	} else {
214 		req->nbd_idx = 0;
215 		req->nbd_device = find_available_nbd_disk(req->nbd_idx, &req->nbd_idx);
216 		if (req->nbd_device == NULL) {
217 			SPDK_INFOLOG(SPDK_LOG_NBD, "There is no available nbd device.\n");
218 			spdk_jsonrpc_send_error_response(request, -ENODEV,
219 							 "nbd device not found");
220 			goto invalid;
221 		}
222 	}
223 
224 	req->request = request;
225 	spdk_nbd_start(req->bdev_name, req->nbd_device,
226 		       spdk_rpc_start_nbd_done, req);
227 
228 	return;
229 
230 invalid:
231 	free_rpc_nbd_start_disk(req);
232 }
233 
234 SPDK_RPC_REGISTER("nbd_start_disk", spdk_rpc_nbd_start_disk, SPDK_RPC_RUNTIME)
235 SPDK_RPC_REGISTER_ALIAS_DEPRECATED(nbd_start_disk, start_nbd_disk)
236 
237 struct rpc_nbd_stop_disk {
238 	char *nbd_device;
239 };
240 
241 static void
242 free_rpc_nbd_stop_disk(struct rpc_nbd_stop_disk *req)
243 {
244 	free(req->nbd_device);
245 }
246 
247 static const struct spdk_json_object_decoder rpc_nbd_stop_disk_decoders[] = {
248 	{"nbd_device", offsetof(struct rpc_nbd_stop_disk, nbd_device), spdk_json_decode_string},
249 };
250 
251 struct nbd_disconnect_arg {
252 	struct spdk_jsonrpc_request *request;
253 	struct spdk_nbd_disk *nbd;
254 };
255 
256 static void *
257 nbd_disconnect_thread(void *arg)
258 {
259 	struct nbd_disconnect_arg *thd_arg = arg;
260 	struct spdk_json_write_ctx *w;
261 
262 	spdk_unaffinitize_thread();
263 
264 	nbd_disconnect(thd_arg->nbd);
265 
266 	w = spdk_jsonrpc_begin_result(thd_arg->request);
267 	spdk_json_write_bool(w, true);
268 	spdk_jsonrpc_end_result(thd_arg->request, w);
269 
270 	free(thd_arg);
271 	pthread_exit(NULL);
272 }
273 
274 static void
275 spdk_rpc_nbd_stop_disk(struct spdk_jsonrpc_request *request,
276 		       const struct spdk_json_val *params)
277 {
278 	struct rpc_nbd_stop_disk req = {};
279 	struct spdk_nbd_disk *nbd;
280 	pthread_t tid;
281 	struct nbd_disconnect_arg *thd_arg = NULL;
282 	int rc;
283 
284 	if (spdk_json_decode_object(params, rpc_nbd_stop_disk_decoders,
285 				    SPDK_COUNTOF(rpc_nbd_stop_disk_decoders),
286 				    &req)) {
287 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
288 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
289 						 "spdk_json_decode_object failed");
290 		goto out;
291 	}
292 
293 	if (req.nbd_device == NULL) {
294 		spdk_jsonrpc_send_error_response(request, -ENODEV, "invalid nbd device");
295 		goto out;
296 	}
297 
298 	/* make sure nbd_device is registered */
299 	nbd = spdk_nbd_disk_find_by_nbd_path(req.nbd_device);
300 	if (!nbd) {
301 		spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
302 		goto out;
303 	}
304 
305 	/*
306 	 * thd_arg should be freed by created thread
307 	 * if thread is created successfully.
308 	 */
309 	thd_arg = malloc(sizeof(*thd_arg));
310 	if (!thd_arg) {
311 		SPDK_ERRLOG("could not allocate nbd disconnect thread arg\n");
312 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, "Out of memory");
313 		goto out;
314 	}
315 
316 	thd_arg->request = request;
317 	thd_arg->nbd = nbd;
318 
319 	/*
320 	 * NBD ioctl of disconnect will block until data are flushed.
321 	 * Create separate thread to execute it.
322 	 */
323 	rc = pthread_create(&tid, NULL, nbd_disconnect_thread, (void *)thd_arg);
324 	if (rc != 0) {
325 		SPDK_ERRLOG("could not create nbd disconnect thread: %s\n", spdk_strerror(rc));
326 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, spdk_strerror(rc));
327 		free(thd_arg);
328 		goto out;
329 	}
330 
331 	rc = pthread_detach(tid);
332 	if (rc != 0) {
333 		SPDK_ERRLOG("could not detach nbd disconnect thread: %s\n", spdk_strerror(rc));
334 		goto out;
335 	}
336 
337 out:
338 	free_rpc_nbd_stop_disk(&req);
339 }
340 
341 SPDK_RPC_REGISTER("nbd_stop_disk", spdk_rpc_nbd_stop_disk, SPDK_RPC_RUNTIME)
342 SPDK_RPC_REGISTER_ALIAS_DEPRECATED(nbd_stop_disk, stop_nbd_disk)
343 
344 static void
345 spdk_rpc_dump_nbd_info(struct spdk_json_write_ctx *w,
346 		       struct spdk_nbd_disk *nbd)
347 {
348 	spdk_json_write_object_begin(w);
349 
350 	spdk_json_write_named_string(w, "nbd_device", spdk_nbd_disk_get_nbd_path(nbd));
351 
352 	spdk_json_write_named_string(w, "bdev_name", spdk_nbd_disk_get_bdev_name(nbd));
353 
354 	spdk_json_write_object_end(w);
355 }
356 
357 struct rpc_nbd_get_disks {
358 	char *nbd_device;
359 };
360 
361 static void
362 free_rpc_nbd_get_disks(struct rpc_nbd_get_disks *r)
363 {
364 	free(r->nbd_device);
365 }
366 
367 static const struct spdk_json_object_decoder rpc_nbd_get_disks_decoders[] = {
368 	{"nbd_device", offsetof(struct rpc_nbd_get_disks, nbd_device), spdk_json_decode_string, true},
369 };
370 
371 static void
372 spdk_rpc_nbd_get_disks(struct spdk_jsonrpc_request *request,
373 		       const struct spdk_json_val *params)
374 {
375 	struct rpc_nbd_get_disks req = {};
376 	struct spdk_json_write_ctx *w;
377 	struct spdk_nbd_disk *nbd = NULL;
378 
379 	if (params != NULL) {
380 		if (spdk_json_decode_object(params, rpc_nbd_get_disks_decoders,
381 					    SPDK_COUNTOF(rpc_nbd_get_disks_decoders),
382 					    &req)) {
383 			SPDK_ERRLOG("spdk_json_decode_object failed\n");
384 			spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
385 							 "spdk_json_decode_object failed");
386 			goto invalid;
387 		}
388 
389 		if (req.nbd_device) {
390 			nbd = spdk_nbd_disk_find_by_nbd_path(req.nbd_device);
391 			if (nbd == NULL) {
392 				SPDK_ERRLOG("nbd device '%s' does not exist\n", req.nbd_device);
393 				spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
394 				goto invalid;
395 			}
396 
397 			free_rpc_nbd_get_disks(&req);
398 		}
399 	}
400 
401 	w = spdk_jsonrpc_begin_result(request);
402 	spdk_json_write_array_begin(w);
403 
404 	if (nbd != NULL) {
405 		spdk_rpc_dump_nbd_info(w, nbd);
406 	} else {
407 		for (nbd = spdk_nbd_disk_first(); nbd != NULL; nbd = spdk_nbd_disk_next(nbd)) {
408 			spdk_rpc_dump_nbd_info(w, nbd);
409 		}
410 	}
411 
412 	spdk_json_write_array_end(w);
413 
414 	spdk_jsonrpc_end_result(request, w);
415 
416 	return;
417 
418 invalid:
419 	free_rpc_nbd_get_disks(&req);
420 }
421 SPDK_RPC_REGISTER("nbd_get_disks", spdk_rpc_nbd_get_disks, SPDK_RPC_RUNTIME)
422 SPDK_RPC_REGISTER_ALIAS_DEPRECATED(nbd_get_disks, get_nbd_disks)
423