Fix: locking order between consumer and stream
[lttng-tools.git] / src / bin / lttng-sessiond / ust-consumer.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24
25 #include <common/common.h>
26 #include <common/consumer.h>
27 #include <common/defaults.h>
28
29 #include "consumer.h"
30 #include "ust-consumer.h"
31
32 /*
33 * Send a single channel to the consumer using command ADD_CHANNEL.
34 */
35 static int send_channel(int sock, struct ust_app_channel *uchan)
36 {
37 int ret, fd;
38 struct lttcomm_consumer_msg msg;
39
40 /* Safety net */
41 assert(uchan);
42
43 if (sock < 0) {
44 ret = -EINVAL;
45 goto error;
46 }
47
48 DBG2("Sending channel %s to UST consumer", uchan->name);
49
50 consumer_init_channel_comm_msg(&msg,
51 LTTNG_CONSUMER_ADD_CHANNEL,
52 uchan->obj->shm_fd,
53 uchan->attr.subbuf_size,
54 uchan->obj->memory_map_size,
55 uchan->name,
56 uchan->streams.count);
57
58 ret = consumer_send_channel(sock, &msg);
59 if (ret < 0) {
60 goto error;
61 }
62
63 fd = uchan->obj->shm_fd;
64 ret = consumer_send_fds(sock, &fd, 1);
65 if (ret < 0) {
66 goto error;
67 }
68
69 error:
70 return ret;
71 }
72
73 /*
74 * Send a single stream to the consumer using ADD_STREAM command.
75 */
76 static int send_channel_stream(int sock, struct ust_app_channel *uchan,
77 struct ust_app_session *usess, struct ltt_ust_stream *stream,
78 struct consumer_output *consumer, const char *pathname)
79 {
80 int ret, fds[2];
81 struct lttcomm_consumer_msg msg;
82
83 /* Safety net */
84 assert(uchan);
85 assert(usess);
86 assert(stream);
87 assert(consumer);
88
89 DBG2("Sending stream %d of channel %s to kernel consumer",
90 stream->obj->shm_fd, uchan->name);
91
92 consumer_init_stream_comm_msg(&msg,
93 LTTNG_CONSUMER_ADD_STREAM,
94 uchan->obj->shm_fd,
95 stream->obj->shm_fd,
96 LTTNG_CONSUMER_ACTIVE_STREAM,
97 DEFAULT_UST_CHANNEL_OUTPUT,
98 stream->obj->memory_map_size,
99 usess->uid,
100 usess->gid,
101 consumer->net_seq_index,
102 0, /* Metadata flag unset */
103 stream->name,
104 pathname,
105 usess->id);
106
107 /* Send stream and file descriptor */
108 fds[0] = stream->obj->shm_fd;
109 fds[1] = stream->obj->wait_fd;
110 ret = consumer_send_stream(sock, consumer, &msg, fds, 2);
111 if (ret < 0) {
112 goto error;
113 }
114
115 error:
116 return ret;
117 }
118
119 /*
120 * Send all stream fds of UST channel to the consumer.
121 */
122 static int send_channel_streams(int sock,
123 struct ust_app_channel *uchan, struct ust_app_session *usess,
124 struct consumer_output *consumer)
125 {
126 int ret;
127 char tmp_path[PATH_MAX];
128 const char *pathname;
129 struct ltt_ust_stream *stream, *tmp;
130
131 DBG("Sending streams of channel %s to UST consumer", uchan->name);
132
133 ret = send_channel(sock, uchan);
134 if (ret < 0) {
135 goto error;
136 }
137
138 /* Get the right path name destination */
139 if (consumer->type == CONSUMER_DST_LOCAL) {
140 /* Set application path to the destination path */
141 ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s/%s",
142 consumer->dst.trace_path, consumer->subdir, usess->path);
143 if (ret < 0) {
144 PERROR("snprintf stream path");
145 goto error;
146 }
147 pathname = tmp_path;
148 DBG3("UST local consumer tracefile path: %s", pathname);
149 } else {
150 ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s",
151 consumer->subdir, usess->path);
152 if (ret < 0) {
153 PERROR("snprintf stream path");
154 goto error;
155 }
156 pathname = tmp_path;
157 DBG3("UST network consumer subdir path: %s", pathname);
158 }
159
160 cds_list_for_each_entry_safe(stream, tmp, &uchan->streams.head, list) {
161 if (!stream->obj->shm_fd) {
162 continue;
163 }
164
165 ret = send_channel_stream(sock, uchan, usess, stream, consumer,
166 pathname);
167 if (ret < 0) {
168 goto error;
169 }
170 }
171
172 DBG("UST consumer channel streams sent");
173
174 return 0;
175
176 error:
177 return ret;
178 }
179
180 /*
181 * Sending metadata to the consumer with command ADD_CHANNEL and ADD_STREAM.
182 */
183 static int send_metadata(int sock, struct ust_app_session *usess,
184 struct consumer_output *consumer)
185 {
186 int ret, fd, fds[2];
187 char tmp_path[PATH_MAX];
188 const char *pathname;
189 struct lttcomm_consumer_msg msg;
190
191 /* Safety net */
192 assert(usess);
193 assert(consumer);
194
195 if (sock < 0) {
196 ERR("Consumer socket is negative (%d)", sock);
197 return -EINVAL;
198 }
199
200 if (usess->metadata->obj->shm_fd == 0) {
201 ERR("Metadata obj shm_fd is 0");
202 ret = -1;
203 goto error;
204 }
205
206 DBG("UST consumer sending metadata stream fd");
207
208 consumer_init_channel_comm_msg(&msg,
209 LTTNG_CONSUMER_ADD_CHANNEL,
210 usess->metadata->obj->shm_fd,
211 usess->metadata->attr.subbuf_size,
212 usess->metadata->obj->memory_map_size,
213 "metadata",
214 1);
215
216 ret = consumer_send_channel(sock, &msg);
217 if (ret < 0) {
218 goto error;
219 }
220
221 /* Sending metadata shared memory fd */
222 fd = usess->metadata->obj->shm_fd;
223 ret = consumer_send_fds(sock, &fd, 1);
224 if (ret < 0) {
225 goto error;
226 }
227
228 /* Get correct path name destination */
229 if (consumer->type == CONSUMER_DST_LOCAL) {
230 /* Set application path to the destination path */
231 ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s/%s",
232 consumer->dst.trace_path, consumer->subdir, usess->path);
233 if (ret < 0) {
234 PERROR("snprintf stream path");
235 goto error;
236 }
237 pathname = tmp_path;
238
239 /* Create directory */
240 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG,
241 usess->uid, usess->gid);
242 if (ret < 0) {
243 if (ret != -EEXIST) {
244 ERR("Trace directory creation error");
245 goto error;
246 }
247 }
248 } else {
249 ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s",
250 consumer->subdir, usess->path);
251 if (ret < 0) {
252 PERROR("snprintf metadata path");
253 goto error;
254 }
255 pathname = tmp_path;
256 }
257
258 consumer_init_stream_comm_msg(&msg,
259 LTTNG_CONSUMER_ADD_STREAM,
260 usess->metadata->obj->shm_fd,
261 usess->metadata->stream_obj->shm_fd,
262 LTTNG_CONSUMER_ACTIVE_STREAM,
263 DEFAULT_UST_CHANNEL_OUTPUT,
264 usess->metadata->stream_obj->memory_map_size,
265 usess->uid,
266 usess->gid,
267 consumer->net_seq_index,
268 1, /* Flag metadata set */
269 "metadata",
270 pathname,
271 usess->id);
272
273 /* Send stream and file descriptor */
274 fds[0] = usess->metadata->stream_obj->shm_fd;
275 fds[1] = usess->metadata->stream_obj->wait_fd;
276 ret = consumer_send_stream(sock, consumer, &msg, fds, 2);
277 if (ret < 0) {
278 goto error;
279 }
280
281 error:
282 return ret;
283 }
284
285 /*
286 * Send all stream fds of the UST session to the consumer.
287 */
288 int ust_consumer_send_session(struct ust_app_session *usess,
289 struct consumer_output *consumer, struct consumer_socket *sock)
290 {
291 int ret = 0;
292 struct lttng_ht_iter iter;
293 struct ust_app_channel *ua_chan;
294
295 assert(usess);
296
297 if (consumer == NULL || sock == NULL) {
298 /* There is no consumer so just ignoring the command. */
299 DBG("UST consumer does not exist. Not sending streams");
300 return 0;
301 }
302
303 DBG("Sending metadata stream fd to consumer on %d", sock->fd);
304
305 pthread_mutex_lock(sock->lock);
306
307 /* Sending metadata information to the consumer */
308 ret = send_metadata(sock->fd, usess, consumer);
309 if (ret < 0) {
310 goto error;
311 }
312
313 /* Send each channel fd streams of session */
314 rcu_read_lock();
315 cds_lfht_for_each_entry(usess->channels->ht, &iter.iter, ua_chan,
316 node.node) {
317 /*
318 * Indicate that the channel was not created on the tracer side so skip
319 * sending unexisting streams.
320 */
321 if (ua_chan->obj == NULL) {
322 continue;
323 }
324
325 ret = send_channel_streams(sock->fd, ua_chan, usess, consumer);
326 if (ret < 0) {
327 rcu_read_unlock();
328 goto error;
329 }
330 }
331 rcu_read_unlock();
332
333 DBG("consumer fds (metadata and channel streams) sent");
334
335 /* All good! */
336 ret = 0;
337
338 error:
339 pthread_mutex_unlock(sock->lock);
340 return ret;
341 }
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