| 1 | /* |
| 2 | * Copyright (C) 2013 David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | #include "snapshot.hpp" |
| 10 | #include "utils.hpp" |
| 11 | |
| 12 | #include <common/defaults.hpp> |
| 13 | #include <common/urcu.hpp> |
| 14 | |
| 15 | #include <inttypes.h> |
| 16 | #include <string.h> |
| 17 | #include <urcu/uatomic.h> |
| 18 | |
| 19 | /* |
| 20 | * Return the atomically incremented value of next_output_id. |
| 21 | */ |
| 22 | static inline unsigned long get_next_output_id(struct snapshot *snapshot) |
| 23 | { |
| 24 | return uatomic_add_return(&snapshot->next_output_id, 1); |
| 25 | } |
| 26 | |
| 27 | /* |
| 28 | * Initialized snapshot output with the given values. |
| 29 | * |
| 30 | * Return 0 on success or else a negative value. |
| 31 | */ |
| 32 | static int output_init(const struct ltt_session *session, |
| 33 | uint64_t max_size, |
| 34 | const char *name, |
| 35 | struct lttng_uri *uris, |
| 36 | size_t nb_uri, |
| 37 | struct consumer_output *consumer, |
| 38 | struct snapshot_output *output, |
| 39 | struct snapshot *snapshot) |
| 40 | { |
| 41 | int ret = 0, i; |
| 42 | |
| 43 | memset(output, 0, sizeof(struct snapshot_output)); |
| 44 | |
| 45 | /* |
| 46 | * max_size of -1ULL means unset. Set to default (unlimited). |
| 47 | */ |
| 48 | if (max_size == (uint64_t) -1ULL) { |
| 49 | max_size = 0; |
| 50 | } |
| 51 | output->max_size = max_size; |
| 52 | |
| 53 | if (snapshot) { |
| 54 | output->id = get_next_output_id(snapshot); |
| 55 | } |
| 56 | lttng_ht_node_init_ulong(&output->node, (unsigned long) output->id); |
| 57 | |
| 58 | if (name && name[0] != '\0') { |
| 59 | if (lttng_strncpy(output->name, name, sizeof(output->name))) { |
| 60 | ret = -LTTNG_ERR_INVALID; |
| 61 | goto error; |
| 62 | } |
| 63 | } else { |
| 64 | /* Set default name. */ |
| 65 | ret = snprintf(output->name, |
| 66 | sizeof(output->name), |
| 67 | "%s-%" PRIu32, |
| 68 | DEFAULT_SNAPSHOT_NAME, |
| 69 | output->id); |
| 70 | if (ret < 0) { |
| 71 | ret = -ENOMEM; |
| 72 | goto error; |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | if (!consumer) { |
| 77 | goto end; |
| 78 | } |
| 79 | |
| 80 | output->consumer = consumer_copy_output(consumer); |
| 81 | if (!output->consumer) { |
| 82 | ret = -ENOMEM; |
| 83 | goto error; |
| 84 | } |
| 85 | output->consumer->snapshot = 1; |
| 86 | |
| 87 | /* No URL given. */ |
| 88 | if (nb_uri == 0) { |
| 89 | ret = 0; |
| 90 | goto end; |
| 91 | } |
| 92 | |
| 93 | if (uris[0].dtype == LTTNG_DST_PATH) { |
| 94 | memset(output->consumer->dst.session_root_path, |
| 95 | 0, |
| 96 | sizeof(output->consumer->dst.session_root_path)); |
| 97 | if (lttng_strncpy(output->consumer->dst.session_root_path, |
| 98 | uris[0].dst.path, |
| 99 | sizeof(output->consumer->dst.session_root_path))) { |
| 100 | ret = -LTTNG_ERR_INVALID; |
| 101 | goto error; |
| 102 | } |
| 103 | output->consumer->type = CONSUMER_DST_LOCAL; |
| 104 | ret = 0; |
| 105 | goto end; |
| 106 | } |
| 107 | |
| 108 | if (nb_uri != 2) { |
| 109 | /* Absolutely needs two URIs for network. */ |
| 110 | ret = -LTTNG_ERR_INVALID; |
| 111 | goto error; |
| 112 | } |
| 113 | |
| 114 | for (i = 0; i < nb_uri; i++) { |
| 115 | /* Network URIs */ |
| 116 | ret = consumer_set_network_uri(session, output->consumer, &uris[i]); |
| 117 | if (ret < 0) { |
| 118 | goto error; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | error: |
| 123 | end: |
| 124 | return ret; |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * Initialize a snapshot output object using the given parameters and URI(s). |
| 129 | * The name value and uris can be NULL. |
| 130 | * |
| 131 | * Return 0 on success or else a negative value. |
| 132 | */ |
| 133 | int snapshot_output_init_with_uri(const struct ltt_session *session, |
| 134 | uint64_t max_size, |
| 135 | const char *name, |
| 136 | struct lttng_uri *uris, |
| 137 | size_t nb_uri, |
| 138 | struct consumer_output *consumer, |
| 139 | struct snapshot_output *output, |
| 140 | struct snapshot *snapshot) |
| 141 | { |
| 142 | return output_init(session, max_size, name, uris, nb_uri, consumer, output, snapshot); |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * Initialize a snapshot output object using the given parameters. The name |
| 147 | * value and url can be NULL. |
| 148 | * |
| 149 | * Return 0 on success or else a negative value. |
| 150 | */ |
| 151 | int snapshot_output_init(const struct ltt_session *session, |
| 152 | uint64_t max_size, |
| 153 | const char *name, |
| 154 | const char *ctrl_url, |
| 155 | const char *data_url, |
| 156 | struct consumer_output *consumer, |
| 157 | struct snapshot_output *output, |
| 158 | struct snapshot *snapshot) |
| 159 | { |
| 160 | int ret = 0, nb_uri; |
| 161 | struct lttng_uri *uris = nullptr; |
| 162 | |
| 163 | /* Create an array of URIs from URLs. */ |
| 164 | nb_uri = uri_parse_str_urls(ctrl_url, data_url, &uris); |
| 165 | if (nb_uri < 0) { |
| 166 | ret = nb_uri; |
| 167 | goto error; |
| 168 | } |
| 169 | |
| 170 | ret = output_init(session, max_size, name, uris, nb_uri, consumer, output, snapshot); |
| 171 | |
| 172 | error: |
| 173 | free(uris); |
| 174 | return ret; |
| 175 | } |
| 176 | |
| 177 | struct snapshot_output *snapshot_output_alloc() |
| 178 | { |
| 179 | return zmalloc<snapshot_output>(); |
| 180 | } |
| 181 | |
| 182 | /* |
| 183 | * Delete output from the snapshot object. |
| 184 | */ |
| 185 | void snapshot_delete_output(struct snapshot *snapshot, struct snapshot_output *output) |
| 186 | { |
| 187 | int ret; |
| 188 | struct lttng_ht_iter iter; |
| 189 | |
| 190 | LTTNG_ASSERT(snapshot); |
| 191 | LTTNG_ASSERT(snapshot->output_ht); |
| 192 | LTTNG_ASSERT(output); |
| 193 | |
| 194 | iter.iter.node = &output->node.node; |
| 195 | lttng::urcu::read_lock_guard read_lock; |
| 196 | ret = lttng_ht_del(snapshot->output_ht, &iter); |
| 197 | LTTNG_ASSERT(!ret); |
| 198 | /* |
| 199 | * This is safe because the ownership of a snapshot object is in a session |
| 200 | * for which the session lock need to be acquired to read and modify it. |
| 201 | */ |
| 202 | snapshot->nb_output--; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Add output object to the snapshot. |
| 207 | */ |
| 208 | void snapshot_add_output(struct snapshot *snapshot, struct snapshot_output *output) |
| 209 | { |
| 210 | LTTNG_ASSERT(snapshot); |
| 211 | LTTNG_ASSERT(snapshot->output_ht); |
| 212 | LTTNG_ASSERT(output); |
| 213 | |
| 214 | lttng::urcu::read_lock_guard read_lock; |
| 215 | lttng_ht_add_unique_ulong(snapshot->output_ht, &output->node); |
| 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 | LTTNG_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, struct snapshot *snapshot) |
| 244 | { |
| 245 | struct lttng_ht_iter iter; |
| 246 | struct snapshot_output *output = nullptr; |
| 247 | |
| 248 | LTTNG_ASSERT(snapshot); |
| 249 | LTTNG_ASSERT(name); |
| 250 | ASSERT_RCU_READ_LOCKED(); |
| 251 | |
| 252 | cds_lfht_for_each_entry (snapshot->output_ht->ht, &iter.iter, output, node.node) { |
| 253 | if (!strncmp(output->name, name, strlen(name))) { |
| 254 | return output; |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | /* Not found */ |
| 259 | return nullptr; |
| 260 | } |
| 261 | |
| 262 | /* |
| 263 | * RCU read side lock MUST be acquired before calling this since the returned |
| 264 | * pointer is in a RCU hash table. |
| 265 | * |
| 266 | * Return the reference on success or else NULL. |
| 267 | */ |
| 268 | struct snapshot_output *snapshot_find_output_by_id(uint32_t id, struct snapshot *snapshot) |
| 269 | { |
| 270 | struct lttng_ht_node_ulong *node; |
| 271 | struct lttng_ht_iter iter; |
| 272 | struct snapshot_output *output = nullptr; |
| 273 | |
| 274 | LTTNG_ASSERT(snapshot); |
| 275 | ASSERT_RCU_READ_LOCKED(); |
| 276 | |
| 277 | lttng_ht_lookup(snapshot->output_ht, (void *) ((unsigned long) id), &iter); |
| 278 | node = lttng_ht_iter_get_node_ulong(&iter); |
| 279 | if (!node) { |
| 280 | DBG3("Snapshot output not found with id %" PRId32, id); |
| 281 | goto error; |
| 282 | } |
| 283 | output = lttng::utils::container_of(node, &snapshot_output::node); |
| 284 | |
| 285 | error: |
| 286 | return output; |
| 287 | } |
| 288 | |
| 289 | /* |
| 290 | * Initialized a snapshot object that was already allocated. |
| 291 | * |
| 292 | * Return 0 on success or else a negative errno value. |
| 293 | */ |
| 294 | int snapshot_init(struct snapshot *obj) |
| 295 | { |
| 296 | int ret; |
| 297 | |
| 298 | LTTNG_ASSERT(obj); |
| 299 | |
| 300 | memset(obj, 0, sizeof(struct snapshot)); |
| 301 | |
| 302 | obj->output_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); |
| 303 | if (!obj->output_ht) { |
| 304 | ret = -ENOMEM; |
| 305 | goto error; |
| 306 | } |
| 307 | |
| 308 | ret = 0; |
| 309 | |
| 310 | error: |
| 311 | return ret; |
| 312 | } |
| 313 | |
| 314 | /* |
| 315 | * Destroy snapshot object but the pointer is not freed so it's safe to pass a |
| 316 | * static reference. |
| 317 | */ |
| 318 | void snapshot_destroy(struct snapshot *obj) |
| 319 | { |
| 320 | struct lttng_ht_iter iter; |
| 321 | struct snapshot_output *output; |
| 322 | |
| 323 | if (!obj->output_ht) { |
| 324 | return; |
| 325 | } |
| 326 | |
| 327 | { |
| 328 | lttng::urcu::read_lock_guard read_lock; |
| 329 | |
| 330 | cds_lfht_for_each_entry (obj->output_ht->ht, &iter.iter, output, node.node) { |
| 331 | snapshot_delete_output(obj, output); |
| 332 | snapshot_output_destroy(output); |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | lttng_ht_destroy(obj->output_ht); |
| 337 | } |