Fix: relay: viewer_get_next_index handle null vstream
[lttng-tools.git] / src / bin / lttng-relayd / stream.c
CommitLineData
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1/*
2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
7591bab1 4 * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20#define _GNU_SOURCE
6c1c0768 21#define _LGPL_SOURCE
2a174661 22#include <common/common.h>
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23#include <common/utils.h>
24#include <common/defaults.h>
25#include <urcu/rculist.h>
26#include <sys/stat.h>
2a174661 27
7591bab1 28#include "lttng-relayd.h"
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29#include "index.h"
30#include "stream.h"
31#include "viewer-stream.h"
32
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33/* Should be called with RCU read-side lock held. */
34bool stream_get(struct relay_stream *stream)
35{
36 bool has_ref = false;
37
38 pthread_mutex_lock(&stream->reflock);
39 if (stream->ref.refcount != 0) {
40 has_ref = true;
41 urcu_ref_get(&stream->ref);
42 }
43 pthread_mutex_unlock(&stream->reflock);
44
45 return has_ref;
46}
47
2a174661 48/*
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49 * Get stream from stream id from the streams hash table. Return stream
50 * if found else NULL. A stream reference is taken when a stream is
51 * returned. stream_put() must be called on that stream.
2a174661 52 */
7591bab1 53struct relay_stream *stream_get_by_id(uint64_t stream_id)
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54{
55 struct lttng_ht_node_u64 *node;
56 struct lttng_ht_iter iter;
57 struct relay_stream *stream = NULL;
58
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59 rcu_read_lock();
60 lttng_ht_lookup(relay_streams_ht, &stream_id, &iter);
2a174661 61 node = lttng_ht_iter_get_node_u64(&iter);
7591bab1 62 if (!node) {
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63 DBG("Relay stream %" PRIu64 " not found", stream_id);
64 goto end;
65 }
66 stream = caa_container_of(node, struct relay_stream, node);
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67 if (!stream_get(stream)) {
68 stream = NULL;
69 }
2a174661 70end:
7591bab1 71 rcu_read_unlock();
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72 return stream;
73}
74
75/*
7591bab1 76 * We keep ownership of path_name and channel_name.
2a174661 77 */
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78struct relay_stream *stream_create(struct ctf_trace *trace,
79 uint64_t stream_handle, char *path_name,
80 char *channel_name, uint64_t tracefile_size,
81 uint64_t tracefile_count)
2a174661 82{
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83 int ret;
84 struct relay_stream *stream = NULL;
85 struct relay_session *session = trace->session;
2a174661 86
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87 stream = zmalloc(sizeof(struct relay_stream));
88 if (stream == NULL) {
89 PERROR("relay stream zmalloc");
90 ret = -1;
91 goto error_no_alloc;
92 }
2a174661 93
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94 stream->stream_handle = stream_handle;
95 stream->prev_seq = -1ULL;
96 stream->ctf_stream_id = -1ULL;
97 stream->tracefile_size = tracefile_size;
98 stream->tracefile_count = tracefile_count;
99 stream->path_name = path_name;
100 stream->channel_name = channel_name;
101 lttng_ht_node_init_u64(&stream->node, stream->stream_handle);
102 pthread_mutex_init(&stream->lock, NULL);
103 pthread_mutex_init(&stream->reflock, NULL);
104 urcu_ref_init(&stream->ref);
105 ctf_trace_get(trace);
106 stream->trace = trace;
2a174661 107
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108 stream->indexes_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
109 if (!stream->indexes_ht) {
110 ERR("Cannot created indexes_ht");
111 ret = -1;
112 goto end;
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113 }
114
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115 ret = utils_mkdir_recursive(stream->path_name, S_IRWXU | S_IRWXG,
116 -1, -1);
117 if (ret < 0) {
118 ERR("relay creating output directory");
119 goto end;
120 }
2a174661 121
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122 /*
123 * No need to use run_as API here because whatever we receive,
124 * the relayd uses its own credentials for the stream files.
125 */
126 ret = utils_create_stream_file(stream->path_name, stream->channel_name,
127 stream->tracefile_size, 0, -1, -1, NULL);
128 if (ret < 0) {
129 ERR("Create output file");
130 goto end;
131 }
132 stream->stream_fd = stream_fd_create(ret);
133 if (!stream->stream_fd) {
134 if (close(ret)) {
135 PERROR("Error closing file %d", ret);
2a174661 136 }
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137 ret = -1;
138 goto end;
2a174661 139 }
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140 if (stream->tracefile_size) {
141 DBG("Tracefile %s/%s_0 created", stream->path_name, stream->channel_name);
142 } else {
143 DBG("Tracefile %s/%s created", stream->path_name, stream->channel_name);
144 }
145
146 if (!strncmp(stream->channel_name, DEFAULT_METADATA_NAME, NAME_MAX)) {
147 stream->is_metadata = 1;
148 }
149
150 stream->in_recv_list = true;
151
152 /*
153 * Add the stream in the recv list of the session. Once the end stream
154 * message is received, all session streams are published.
155 */
156 pthread_mutex_lock(&session->recv_list_lock);
157 cds_list_add_rcu(&stream->recv_node, &session->recv_list);
158 session->stream_count++;
159 pthread_mutex_unlock(&session->recv_list_lock);
160
161 /*
162 * Both in the ctf_trace object and the global stream ht since the data
163 * side of the relayd does not have the concept of session.
164 */
165 lttng_ht_add_unique_u64(relay_streams_ht, &stream->node);
2a174661 166
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167 DBG("Relay new stream added %s with ID %" PRIu64, stream->channel_name,
168 stream->stream_handle);
169 ret = 0;
170
171end:
172 if (ret) {
173 if (stream->stream_fd) {
174 stream_fd_put(stream->stream_fd);
175 stream->stream_fd = NULL;
2a174661 176 }
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177 stream_put(stream);
178 stream = NULL;
2a174661 179 }
7591bab1 180 return stream;
2a174661 181
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182error_no_alloc:
183 /*
184 * path_name and channel_name need to be freed explicitly here
185 * because we cannot rely on stream_put().
186 */
187 free(path_name);
188 free(channel_name);
189 return NULL;
190}
191
192/*
193 * Called with the session lock held.
194 */
195void stream_publish(struct relay_stream *stream)
196{
197 struct relay_session *session;
198
199 pthread_mutex_lock(&stream->lock);
200 if (stream->published) {
201 goto unlock;
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202 }
203
7591bab1 204 session = stream->trace->session;
2a174661 205
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206 pthread_mutex_lock(&session->recv_list_lock);
207 if (stream->in_recv_list) {
208 cds_list_del_rcu(&stream->recv_node);
209 stream->in_recv_list = false;
210 }
211 pthread_mutex_unlock(&session->recv_list_lock);
2a174661 212
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213 pthread_mutex_lock(&stream->trace->stream_list_lock);
214 cds_list_add_rcu(&stream->stream_node, &stream->trace->stream_list);
215 pthread_mutex_unlock(&stream->trace->stream_list_lock);
2a174661 216
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217 stream->published = true;
218unlock:
2a174661 219 pthread_mutex_unlock(&stream->lock);
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220}
221
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222/*
223 * Only called from destroy. No stream lock needed, since there is a
224 * single user at this point. This is ensured by having the refcount
225 * reaching 0.
226 */
227static void stream_unpublish(struct relay_stream *stream)
2a174661 228{
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229 if (!stream->published) {
230 return;
231 }
232 pthread_mutex_lock(&stream->trace->stream_list_lock);
233 cds_list_del_rcu(&stream->stream_node);
234 pthread_mutex_unlock(&stream->trace->stream_list_lock);
235
236 stream->published = false;
237}
238
239static void stream_destroy(struct relay_stream *stream)
240{
241 if (stream->indexes_ht) {
242 lttng_ht_destroy(stream->indexes_ht);
243 }
244 free(stream->path_name);
245 free(stream->channel_name);
246 free(stream);
247}
248
249static void stream_destroy_rcu(struct rcu_head *rcu_head)
250{
251 struct relay_stream *stream =
252 caa_container_of(rcu_head, struct relay_stream, rcu_node);
253
254 stream_destroy(stream);
255}
256
257/*
258 * No need to take stream->lock since this is only called on the final
259 * stream_put which ensures that a single thread may act on the stream.
260 *
261 * At that point, the object is also protected by the reflock which
262 * guarantees that no other thread may share ownership of this stream.
263 */
264static void stream_release(struct urcu_ref *ref)
265{
266 struct relay_stream *stream =
267 caa_container_of(ref, struct relay_stream, ref);
268 struct relay_session *session;
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269 int ret;
270 struct lttng_ht_iter iter;
271
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272 session = stream->trace->session;
273
274 DBG("Releasing stream id %" PRIu64, stream->stream_handle);
275
276 pthread_mutex_lock(&session->recv_list_lock);
277 session->stream_count--;
278 if (stream->in_recv_list) {
279 cds_list_del_rcu(&stream->recv_node);
280 stream->in_recv_list = false;
281 }
282 pthread_mutex_unlock(&session->recv_list_lock);
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283
284 iter.iter.node = &stream->node.node;
7591bab1 285 ret = lttng_ht_del(relay_streams_ht, &iter);
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286 assert(!ret);
287
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288 stream_unpublish(stream);
289
290 if (stream->stream_fd) {
291 stream_fd_put(stream->stream_fd);
292 stream->stream_fd = NULL;
293 }
294 if (stream->index_fd) {
295 stream_fd_put(stream->index_fd);
296 stream->index_fd = NULL;
297 }
298 if (stream->trace) {
299 ctf_trace_put(stream->trace);
300 stream->trace = NULL;
301 }
302
303 call_rcu(&stream->rcu_node, stream_destroy_rcu);
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304}
305
7591bab1 306void stream_put(struct relay_stream *stream)
2a174661 307{
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308 DBG("stream put for stream id %" PRIu64, stream->stream_handle);
309 /*
310 * Ensure existence of stream->reflock for stream unlock.
311 */
312 rcu_read_lock();
313 /*
314 * Stream reflock ensures that concurrent test and update of
315 * stream ref is atomic.
316 */
317 pthread_mutex_lock(&stream->reflock);
318 assert(stream->ref.refcount != 0);
319 /*
320 * Wait until we have processed all the stream packets before
321 * actually putting our last stream reference.
322 */
323 DBG("stream put stream id %" PRIu64 " refcount %d",
324 stream->stream_handle,
325 (int) stream->ref.refcount);
326 urcu_ref_put(&stream->ref, stream_release);
327 pthread_mutex_unlock(&stream->reflock);
328 rcu_read_unlock();
329}
330
331void stream_close(struct relay_stream *stream)
332{
333 DBG("closing stream %" PRIu64, stream->stream_handle);
334 pthread_mutex_lock(&stream->lock);
2229a09c 335 stream->closed = true;
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336 relay_index_close_all(stream);
337 pthread_mutex_unlock(&stream->lock);
338 stream_put(stream);
339}
340
341void print_relay_streams(void)
342{
343 struct lttng_ht_iter iter;
344 struct relay_stream *stream;
345
346 rcu_read_lock();
347 cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
348 node.node) {
349 if (!stream_get(stream)) {
350 continue;
351 }
352 DBG("stream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
353 " session %" PRIu64,
354 stream,
355 stream->ref.refcount,
356 stream->stream_handle,
357 stream->trace->id,
358 stream->trace->session->id);
359 stream_put(stream);
360 }
361 rcu_read_unlock();
2a174661 362}
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