Fix: release reference to ltt_session on error instead of free()
[lttng-tools.git] / src / bin / lttng-sessiond / snapshot.c
1 /*
2 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <assert.h>
20 #include <inttypes.h>
21 #include <string.h>
22 #include <urcu/uatomic.h>
23
24 #include <common/defaults.h>
25
26 #include "snapshot.h"
27 #include "utils.h"
28
29 /*
30 * Return the atomically incremented value of next_output_id.
31 */
32 static inline unsigned long get_next_output_id(struct snapshot *snapshot)
33 {
34 return uatomic_add_return(&snapshot->next_output_id, 1);
35 }
36
37 /*
38 * Initialized snapshot output with the given values.
39 *
40 * Return 0 on success or else a negative value.
41 */
42 static int output_init(uint64_t max_size, const char *name,
43 struct lttng_uri *uris, size_t nb_uri,
44 struct consumer_output *consumer, struct snapshot_output *output,
45 struct snapshot *snapshot)
46 {
47 int ret = 0, i;
48
49 memset(output, 0, sizeof(struct snapshot_output));
50
51 /*
52 * max_size of -1ULL means unset. Set to default (unlimited).
53 */
54 if (max_size == (uint64_t) -1ULL) {
55 max_size = 0;
56 }
57 output->max_size = max_size;
58
59 if (snapshot) {
60 output->id = get_next_output_id(snapshot);
61 }
62 lttng_ht_node_init_ulong(&output->node, (unsigned long) output->id);
63
64 if (name && name[0] != '\0') {
65 if (lttng_strncpy(output->name, name, sizeof(output->name))) {
66 ret = -LTTNG_ERR_INVALID;
67 goto error;
68 }
69 } else {
70 /* Set default name. */
71 ret = snprintf(output->name, sizeof(output->name), "%s-%" PRIu32,
72 DEFAULT_SNAPSHOT_NAME, output->id);
73 if (ret < 0) {
74 ret = -ENOMEM;
75 goto error;
76 }
77 }
78
79 if (!consumer) {
80 goto end;
81 }
82
83 output->consumer = consumer_copy_output(consumer);
84 if (!output->consumer) {
85 ret = -ENOMEM;
86 goto error;
87 }
88 output->consumer->snapshot = 1;
89
90 /* No URL given. */
91 if (nb_uri == 0) {
92 ret = 0;
93 goto end;
94 }
95
96 if (uris[0].dtype == LTTNG_DST_PATH) {
97 memset(output->consumer->dst.session_root_path, 0,
98 sizeof(output->consumer->dst.session_root_path));
99 if (lttng_strncpy(output->consumer->dst.session_root_path,
100 uris[0].dst.path,
101 sizeof(output->consumer->dst.session_root_path))) {
102 ret = -LTTNG_ERR_INVALID;
103 goto error;
104 }
105 output->consumer->type = CONSUMER_DST_LOCAL;
106 ret = 0;
107 goto end;
108 }
109
110 if (nb_uri != 2) {
111 /* Absolutely needs two URIs for network. */
112 ret = -LTTNG_ERR_INVALID;
113 goto error;
114 }
115
116 for (i = 0; i < nb_uri; i ++) {
117 /* Network URIs */
118 ret = consumer_set_network_uri(output->consumer, &uris[i]);
119 if (ret < 0) {
120 goto error;
121 }
122 }
123
124 error:
125 end:
126 return ret;
127 }
128
129 /*
130 * Initialize a snapshot output object using the given parameters and URI(s).
131 * The name value and uris can be NULL.
132 *
133 * Return 0 on success or else a negative value.
134 */
135 int snapshot_output_init_with_uri(uint64_t max_size, const char *name,
136 struct lttng_uri *uris, size_t nb_uri,
137 struct consumer_output *consumer, struct snapshot_output *output,
138 struct snapshot *snapshot)
139 {
140 return output_init(max_size, name, uris, nb_uri, consumer, output,
141 snapshot);
142 }
143
144 /*
145 * Initialize a snapshot output object using the given parameters. The name
146 * value and url can be NULL.
147 *
148 * Return 0 on success or else a negative value.
149 */
150 int snapshot_output_init(uint64_t max_size, const char *name,
151 const char *ctrl_url, const char *data_url,
152 struct consumer_output *consumer, struct snapshot_output *output,
153 struct snapshot *snapshot)
154 {
155 int ret = 0, nb_uri;
156 struct lttng_uri *uris = NULL;
157
158 /* Create an array of URIs from URLs. */
159 nb_uri = uri_parse_str_urls(ctrl_url, data_url, &uris);
160 if (nb_uri < 0) {
161 ret = nb_uri;
162 goto error;
163 }
164
165 ret = output_init(max_size, name, uris, nb_uri, consumer, output,
166 snapshot);
167
168 error:
169 free(uris);
170 return ret;
171 }
172
173 struct snapshot_output *snapshot_output_alloc(void)
174 {
175 return zmalloc(sizeof(struct snapshot_output));
176 }
177
178 /*
179 * Delete output from the snapshot object.
180 */
181 void snapshot_delete_output(struct snapshot *snapshot,
182 struct snapshot_output *output)
183 {
184 int ret;
185 struct lttng_ht_iter iter;
186
187 assert(snapshot);
188 assert(snapshot->output_ht);
189 assert(output);
190
191 iter.iter.node = &output->node.node;
192 rcu_read_lock();
193 ret = lttng_ht_del(snapshot->output_ht, &iter);
194 rcu_read_unlock();
195 assert(!ret);
196 /*
197 * This is safe because the ownership of a snapshot object is in a session
198 * for which the session lock need to be acquired to read and modify it.
199 */
200 snapshot->nb_output--;
201 }
202
203 /*
204 * Add output object to the snapshot.
205 */
206 void snapshot_add_output(struct snapshot *snapshot,
207 struct snapshot_output *output)
208 {
209 assert(snapshot);
210 assert(snapshot->output_ht);
211 assert(output);
212
213 rcu_read_lock();
214 lttng_ht_add_unique_ulong(snapshot->output_ht, &output->node);
215 rcu_read_unlock();
216 /*
217 * This is safe because the ownership of a snapshot object is in a session
218 * for which the session lock need to be acquired to read and modify it.
219 */
220 snapshot->nb_output++;
221 }
222
223 /*
224 * Destroy and free a snapshot output object.
225 */
226 void snapshot_output_destroy(struct snapshot_output *obj)
227 {
228 assert(obj);
229
230 if (obj->consumer) {
231 consumer_output_send_destroy_relayd(obj->consumer);
232 consumer_output_put(obj->consumer);
233 }
234 free(obj);
235 }
236
237 /*
238 * RCU read side lock MUST be acquired before calling this since the returned
239 * pointer is in a RCU hash table.
240 *
241 * Return the reference on success or else NULL.
242 */
243 struct snapshot_output *snapshot_find_output_by_name(const char *name,
244 struct snapshot *snapshot)
245 {
246 struct lttng_ht_iter iter;
247 struct snapshot_output *output = NULL;
248
249 assert(snapshot);
250 assert(name);
251
252 cds_lfht_for_each_entry(snapshot->output_ht->ht, &iter.iter, output,
253 node.node) {
254 if (!strncmp(output->name, name, strlen(name))) {
255 return output;
256 }
257 }
258
259 /* Not found */
260 return NULL;
261 }
262
263 /*
264 * RCU read side lock MUST be acquired before calling this since the returned
265 * pointer is in a RCU hash table.
266 *
267 * Return the reference on success or else NULL.
268 */
269 struct snapshot_output *snapshot_find_output_by_id(uint32_t id,
270 struct snapshot *snapshot)
271 {
272 struct lttng_ht_node_ulong *node;
273 struct lttng_ht_iter iter;
274 struct snapshot_output *output = NULL;
275
276 assert(snapshot);
277
278 lttng_ht_lookup(snapshot->output_ht, (void *)((unsigned long) id), &iter);
279 node = lttng_ht_iter_get_node_ulong(&iter);
280 if (!node) {
281 DBG3("Snapshot output not found with id %" PRId32, id);
282 goto error;
283 }
284 output = caa_container_of(node, struct snapshot_output, node);
285
286 error:
287 return output;
288 }
289
290 /*
291 * Initialized a snapshot object that was already allocated.
292 *
293 * Return 0 on success or else a negative errno value.
294 */
295 int snapshot_init(struct snapshot *obj)
296 {
297 int ret;
298
299 assert(obj);
300
301 memset(obj, 0, sizeof(struct snapshot));
302
303 obj->output_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
304 if (!obj->output_ht) {
305 ret = -ENOMEM;
306 goto error;
307 }
308
309 ret = 0;
310
311 error:
312 return ret;
313 }
314
315 /*
316 * Destroy snapshot object but the pointer is not freed so it's safe to pass a
317 * static reference.
318 */
319 void snapshot_destroy(struct snapshot *obj)
320 {
321 struct lttng_ht_iter iter;
322 struct snapshot_output *output;
323
324 if (!obj->output_ht) {
325 return;
326 }
327
328 rcu_read_lock();
329 cds_lfht_for_each_entry(obj->output_ht->ht, &iter.iter, output,
330 node.node) {
331 snapshot_delete_output(obj, output);
332 snapshot_output_destroy(output);
333 }
334 rcu_read_unlock();
335 ht_cleanup_push(obj->output_ht);
336 }
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