src/bin/lttng-sessiond/buffer-registry.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 _GNU_SOURCE
  19 #include <inttypes.h>
  20
  21 #include <common/common.h>
  22 #include <common/hashtable/utils.h>
  23
  24 #include "buffer-registry.h"
  25 #include "fd-limit.h"
  26 #include "ust-consumer.h"
  27 #include "ust-ctl.h"
  28 #include "utils.h"
  29
  30 /*
  31  * Set in main.c during initialization process of the daemon. This contains
  32  * buffer_reg_uid object which are global registry for per UID buffer. Object
  33  * are indexed by session id and matched by the triplet
  34  * <session_id/bits_per_long/uid>.
  35  */
  36 static struct lttng_ht *buffer_registry_uid;
  37
  38 /*
  39  * Initialized at the daemon start. This contains buffer_reg_pid object and
  40  * indexed by session id.
  41  */
  42 static struct lttng_ht *buffer_registry_pid;
  43
  44 /*
  45  * Match function for the per UID registry hash table. It matches a registry
  46  * uid object with the triplet <session_id/abi/uid>.
  47  */
  48 static int ht_match_reg_uid(struct cds_lfht_node *node, const void *_key)
  49 {
  50         struct buffer_reg_uid *reg;
  51         const struct buffer_reg_uid *key;
  52
  53         assert(node);
  54         assert(_key);
  55
  56         reg = caa_container_of(node, struct buffer_reg_uid, node.node);
  57         assert(reg);
  58         key = _key;
  59
  60         if (key->session_id != reg->session_id ||
  61                         key->bits_per_long != reg->bits_per_long ||
  62                         key->uid != reg->uid) {
  63                 goto no_match;
  64         }
  65
  66         /* Match */
  67         return 1;
  68 no_match:
  69         return 0;
  70 }
  71
  72 /*
  73  * Hash function for the per UID registry hash table. This XOR the triplet
  74  * together.
  75  */
  76 static unsigned long ht_hash_reg_uid(void *_key, unsigned long seed)
  77 {
  78         uint64_t xored_key;
  79         struct buffer_reg_uid *key = _key;
  80
  81         assert(key);
  82
  83         xored_key = (uint64_t)(key->session_id ^ key->bits_per_long ^ key->uid);
  84         return hash_key_u64(&xored_key, seed);
  85 }
  86
  87 /*
  88  * Initialize global buffer per UID registry. Should only be called ONCE!.
  89  */
  90 void buffer_reg_init_uid_registry(void)
  91 {
  92         /* Should be called once. */
  93         assert(!buffer_registry_uid);
  94         buffer_registry_uid = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
  95         assert(buffer_registry_uid);
  96         buffer_registry_uid->match_fct = ht_match_reg_uid;
  97         buffer_registry_uid->hash_fct = ht_hash_reg_uid;
  98
  99         DBG3("Global buffer per UID registry initialized");
 100 }
 101
 102 /*
 103  * Allocate and initialize object. Set regp with the object pointer.
 104  *
 105  * Return 0 on success else a negative value and regp is untouched.
 106  */
 107 int buffer_reg_uid_create(int session_id, uint32_t bits_per_long, uid_t uid,
 108                 enum lttng_domain_type domain, struct buffer_reg_uid **regp)
 109 {
 110         int ret = 0;
 111         struct buffer_reg_uid *reg = NULL;
 112
 113         assert(regp);
 114
 115         reg = zmalloc(sizeof(*reg));
 116         if (!reg) {
 117                 PERROR("zmalloc buffer registry uid");
 118                 ret = -ENOMEM;
 119                 goto error;
 120         }
 121
 122         reg->registry = zmalloc(sizeof(struct buffer_reg_session));
 123         if (!reg->registry) {
 124                 PERROR("zmalloc buffer registry uid session");
 125                 ret = -ENOMEM;
 126                 goto error;
 127         }
 128
 129         reg->session_id = session_id;
 130         reg->bits_per_long = bits_per_long;
 131         reg->uid = uid;
 132         reg->domain = domain;
 133
 134         reg->registry->channels = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 135         if (!reg->registry->channels) {
 136                 ret = -ENOMEM;
 137                 goto error_session;
 138         }
 139
 140         cds_lfht_node_init(&reg->node.node);
 141         *regp = reg;
 142
 143         DBG3("Buffer registry per UID created id: %d, ABI: %u, uid: %d, domain: %d",
 144                         session_id, bits_per_long, uid, domain);
 145
 146         return 0;
 147
 148 error_session:
 149         free(reg->registry);
 150 error:
 151         free(reg);
 152         return ret;
 153 }
 154
 155 /*
 156  * Add a buffer registry per UID object to the global registry.
 157  */
 158 void buffer_reg_uid_add(struct buffer_reg_uid *reg)
 159 {
 160         struct cds_lfht_node *nodep;
 161         struct lttng_ht *ht = buffer_registry_uid;
 162
 163         assert(reg);
 164
 165         DBG3("Buffer registry per UID adding to global registry with id: %d",
 166                         reg->session_id);
 167
 168         rcu_read_lock();
 169         nodep = cds_lfht_add_unique(ht->ht, ht->hash_fct(reg, lttng_ht_seed),
 170                         ht->match_fct, reg, &reg->node.node);
 171         assert(nodep == &reg->node.node);
 172         rcu_read_unlock();
 173 }
 174
 175 /*
 176  * Find a buffer registry per UID object with given params. RCU read side lock
 177  * MUST be acquired before calling this and hold on to protect the object.
 178  *
 179  * Return the object pointer or NULL on error.
 180  */
 181 struct buffer_reg_uid *buffer_reg_uid_find(int session_id,
 182                 uint32_t bits_per_long, uid_t uid)
 183 {
 184         struct lttng_ht_node_u64 *node;
 185         struct lttng_ht_iter iter;
 186         struct buffer_reg_uid *reg = NULL, key;
 187         struct lttng_ht *ht = buffer_registry_uid;
 188
 189         /* Setup key we are looking for. */
 190         key.session_id = session_id;
 191         key.bits_per_long = bits_per_long;
 192         key.uid = uid;
 193
 194         DBG3("Buffer registry per UID find id: %d, ABI: %u, uid: %d",
 195                         session_id, bits_per_long, uid);
 196
 197         /* Custom lookup function since it's a different key. */
 198         cds_lfht_lookup(ht->ht, ht->hash_fct(&key, lttng_ht_seed), ht->match_fct,
 199                         &key, &iter.iter);
 200         node = lttng_ht_iter_get_node_u64(&iter);
 201         if (!node) {
 202                 goto end;
 203         }
 204         reg = caa_container_of(node, struct buffer_reg_uid, node);
 205
 206 end:
 207         return reg;
 208 }
 209
 210 /*
 211  * Initialize global buffer per PID registry. Should only be called ONCE!.
 212  */
 213 void buffer_reg_init_pid_registry(void)
 214 {
 215         /* Should be called once. */
 216         assert(!buffer_registry_pid);
 217         buffer_registry_pid = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 218         assert(buffer_registry_pid);
 219
 220         DBG3("Global buffer per PID registry initialized");
 221 }
 222
 223 /*
 224  * Allocate and initialize object. Set regp with the object pointer.
 225  *
 226  * Return 0 on success else a negative value and regp is untouched.
 227  */
 228 int buffer_reg_pid_create(int session_id, struct buffer_reg_pid **regp)
 229 {
 230         int ret = 0;
 231         struct buffer_reg_pid *reg = NULL;
 232
 233         assert(regp);
 234
 235         reg = zmalloc(sizeof(*reg));
 236         if (!reg) {
 237                 PERROR("zmalloc buffer registry pid");
 238                 ret = -ENOMEM;
 239                 goto error;
 240         }
 241
 242         reg->registry = zmalloc(sizeof(struct buffer_reg_session));
 243         if (!reg->registry) {
 244                 PERROR("zmalloc buffer registry pid session");
 245                 ret = -ENOMEM;
 246                 goto error;
 247         }
 248
 249         /* A cast is done here so we can use the session ID as a u64 ht node. */
 250         reg->session_id = session_id;
 251
 252         reg->registry->channels = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 253         if (!reg->registry->channels) {
 254                 ret = -ENOMEM;
 255                 goto error_session;
 256         }
 257
 258         lttng_ht_node_init_ulong(&reg->node, reg->session_id);
 259         *regp = reg;
 260
 261         DBG3("Buffer registry per PID created with session id: %d", session_id);
 262
 263         return 0;
 264
 265 error_session:
 266         free(reg->registry);
 267 error:
 268         free(reg);
 269         return ret;
 270 }
 271
 272 /*
 273  * Add a buffer registry per PID object to the global registry.
 274  */
 275 void buffer_reg_pid_add(struct buffer_reg_pid *reg)
 276 {
 277         assert(reg);
 278
 279         DBG3("Buffer registry per PID adding to global registry with id: %d",
 280                         reg->session_id);
 281
 282         rcu_read_lock();
 283         lttng_ht_add_unique_ulong(buffer_registry_pid, &reg->node);
 284         rcu_read_unlock();
 285 }
 286
 287 /*
 288  * Find a buffer registry per PID object with given params. RCU read side lock
 289  * MUST be acquired before calling this and hold on to protect the object.
 290  *
 291  * Return the object pointer or NULL on error.
 292  */
 293 struct buffer_reg_pid *buffer_reg_pid_find(int session_id)
 294 {
 295         struct lttng_ht_node_ulong *node;
 296         struct lttng_ht_iter iter;
 297         struct buffer_reg_pid *reg = NULL;
 298         struct lttng_ht *ht = buffer_registry_pid;
 299
 300         DBG3("Buffer registry per PID find id: %d", session_id);
 301
 302         lttng_ht_lookup(ht, (void *)((unsigned long) session_id), &iter);
 303         node = lttng_ht_iter_get_node_ulong(&iter);
 304         if (!node) {
 305                 goto end;
 306         }
 307         reg = caa_container_of(node, struct buffer_reg_pid, node);
 308
 309 end:
 310         return reg;
 311 }
 312
 313 /*
 314  * Allocate and initialize a buffer registry channel with the given key. Set
 315  * regp with the object pointer.
 316  *
 317  * Return 0 on success or else a negative value keeping regp untouched.
 318  */
 319 int buffer_reg_channel_create(uint64_t key, struct buffer_reg_channel **regp)
 320 {
 321         struct buffer_reg_channel *reg;
 322
 323         assert(regp);
 324
 325         DBG3("Buffer registry channel create with key: %" PRIu64, key);
 326
 327         reg = zmalloc(sizeof(*reg));
 328         if (!reg) {
 329                 PERROR("zmalloc buffer registry channel");
 330                 return -ENOMEM;
 331         }
 332
 333         reg->key = key;
 334         CDS_INIT_LIST_HEAD(&reg->streams);
 335         pthread_mutex_init(&reg->stream_list_lock, NULL);
 336
 337         lttng_ht_node_init_u64(&reg->node, key);
 338         *regp = reg;
 339
 340         return 0;
 341 }
 342
 343 /*
 344  * Allocate and initialize a buffer registry stream. Set regp with the object
 345  * pointer.
 346  *
 347  * Return 0 on success or else a negative value keeping regp untouched.
 348  */
 349 int buffer_reg_stream_create(struct buffer_reg_stream **regp)
 350 {
 351         struct buffer_reg_stream *reg;
 352
 353         assert(regp);
 354
 355         DBG3("Buffer registry creating stream");
 356
 357         reg = zmalloc(sizeof(*reg));
 358         if (!reg) {
 359                 PERROR("zmalloc buffer registry stream");
 360                 return -ENOMEM;
 361         }
 362
 363         *regp = reg;
 364
 365         return 0;
 366 }
 367
 368 /*
 369  * Add stream to the list in the channel.
 370  */
 371 void buffer_reg_stream_add(struct buffer_reg_stream *stream,
 372                 struct buffer_reg_channel *channel)
 373 {
 374         assert(stream);
 375         assert(channel);
 376
 377         pthread_mutex_lock(&channel->stream_list_lock);
 378         cds_list_add_tail(&stream->lnode, &channel->streams);
 379         pthread_mutex_unlock(&channel->stream_list_lock);
 380 }
 381
 382 /*
 383  * Add a buffer registry channel object to the given session.
 384  */
 385 void buffer_reg_channel_add(struct buffer_reg_session *session,
 386                 struct buffer_reg_channel *channel)
 387 {
 388         assert(session);
 389         assert(channel);
 390
 391         rcu_read_lock();
 392         lttng_ht_add_unique_u64(session->channels, &channel->node);
 393         rcu_read_unlock();
 394 }
 395
 396 /*
 397  * Find a buffer registry channel object with the given key. RCU read side lock
 398  * MUST be acquired and hold on until the object reference is not needed
 399  * anymore.
 400  *
 401  * Return the object pointer or NULL on error.
 402  */
 403 struct buffer_reg_channel *buffer_reg_channel_find(uint64_t key,
 404                 struct buffer_reg_uid *reg)
 405 {
 406         struct lttng_ht_node_u64 *node;
 407         struct lttng_ht_iter iter;
 408         struct buffer_reg_channel *chan = NULL;
 409         struct lttng_ht *ht;
 410
 411         assert(reg);
 412
 413         switch (reg->domain) {
 414         case LTTNG_DOMAIN_UST:
 415                 ht = reg->registry->channels;
 416                 break;
 417         default:
 418                 assert(0);
 419                 goto end;
 420         }
 421
 422         lttng_ht_lookup(ht, &key, &iter);
 423         node = lttng_ht_iter_get_node_u64(&iter);
 424         if (!node) {
 425                 goto end;
 426         }
 427         chan = caa_container_of(node, struct buffer_reg_channel, node);
 428
 429 end:
 430         return chan;
 431 }
 432
 433 /*
 434  * Destroy a buffer registry stream with the given domain.
 435  */
 436 void buffer_reg_stream_destroy(struct buffer_reg_stream *regp,
 437                 enum lttng_domain_type domain)
 438 {
 439         if (!regp) {
 440                 return;
 441         }
 442
 443         DBG3("Buffer registry stream destroy with handle %d",
 444                         regp->obj.ust->handle);
 445
 446         switch (domain) {
 447         case LTTNG_DOMAIN_UST:
 448         {
 449                 int ret;
 450
 451                 ret = ust_ctl_release_object(-1, regp->obj.ust);
 452                 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 453                         ERR("Buffer reg stream release obj handle %d failed with ret %d",
 454                                         regp->obj.ust->handle, ret);
 455                 }
 456                 free(regp->obj.ust);
 457                 lttng_fd_put(LTTNG_FD_APPS, 2);
 458                 break;
 459         }
 460         default:
 461                 assert(0);
 462         }
 463
 464         free(regp);
 465         return;
 466 }
 467
 468 /*
 469  * Remove buffer registry channel object from the session hash table. RCU read
 470  * side lock MUST be acquired before calling this.
 471  */
 472 void buffer_reg_channel_remove(struct buffer_reg_session *session,
 473                 struct buffer_reg_channel *regp)
 474 {
 475         int ret;
 476         struct lttng_ht_iter iter;
 477
 478         assert(session);
 479         assert(regp);
 480
 481         iter.iter.node = &regp->node.node;
 482         ret = lttng_ht_del(session->channels, &iter);
 483         assert(!ret);
 484 }
 485
 486 /*
 487  * Destroy a buffer registry channel with the given domain.
 488  */
 489 void buffer_reg_channel_destroy(struct buffer_reg_channel *regp,
 490                 enum lttng_domain_type domain)
 491 {
 492         if (!regp) {
 493                 return;
 494         }
 495
 496         DBG3("Buffer registry channel destroy with key %" PRIu32, regp->key);
 497
 498         switch (domain) {
 499         case LTTNG_DOMAIN_UST:
 500         {
 501                 int ret;
 502                 struct buffer_reg_stream *sreg, *stmp;
 503                 /* Wipe stream */
 504                 cds_list_for_each_entry_safe(sreg, stmp, &regp->streams, lnode) {
 505                         cds_list_del(&sreg->lnode);
 506                         buffer_reg_stream_destroy(sreg, domain);
 507                 }
 508
 509                 if (regp->obj.ust) {
 510                         ret = ust_ctl_release_object(-1, regp->obj.ust);
 511                         if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 512                                 ERR("Buffer reg channel release obj handle %d failed with ret %d",
 513                                                 regp->obj.ust->handle, ret);
 514                         }
 515                         free(regp->obj.ust);
 516                 }
 517                 lttng_fd_put(LTTNG_FD_APPS, 1);
 518                 break;
 519         }
 520         default:
 521                 assert(0);
 522         }
 523
 524         free(regp);
 525         return;
 526 }
 527
 528 /*
 529  * Destroy a buffer registry session with the given domain.
 530  *
 531  * Should *NOT* be called with RCU read-side lock held.
 532  */
 533 static void buffer_reg_session_destroy(struct buffer_reg_session *regp,
 534                 enum lttng_domain_type domain)
 535 {
 536         int ret;
 537         struct lttng_ht_iter iter;
 538         struct buffer_reg_channel *reg_chan;
 539
 540         DBG3("Buffer registry session destroy");
 541
 542         /* Destroy all channels. */
 543         rcu_read_lock();
 544         cds_lfht_for_each_entry(regp->channels->ht, &iter.iter, reg_chan,
 545                         node.node) {
 546                 ret = lttng_ht_del(regp->channels, &iter);
 547                 assert(!ret);
 548                 buffer_reg_channel_destroy(reg_chan, domain);
 549         }
 550         rcu_read_unlock();
 551
 552         ht_cleanup_push(regp->channels);
 553
 554         switch (domain) {
 555         case LTTNG_DOMAIN_UST:
 556                 ust_registry_session_destroy(regp->reg.ust);
 557                 free(regp->reg.ust);
 558                 break;
 559         default:
 560                 assert(0);
 561         }
 562
 563         free(regp);
 564         return;
 565 }
 566
 567 /*
 568  * Remove buffer registry UID object from the global hash table.
 569  */
 570 void buffer_reg_uid_remove(struct buffer_reg_uid *regp)
 571 {
 572         int ret;
 573         struct lttng_ht_iter iter;
 574
 575         assert(regp);
 576
 577         rcu_read_lock();
 578         iter.iter.node = &regp->node.node;
 579         ret = lttng_ht_del(buffer_registry_uid, &iter);
 580         assert(!ret);
 581         rcu_read_unlock();
 582 }
 583
 584 static void rcu_free_buffer_reg_uid(struct rcu_head *head)
 585 {
 586         struct lttng_ht_node_u64 *node =
 587                 caa_container_of(head, struct lttng_ht_node_u64, head);
 588         struct buffer_reg_uid *reg =
 589                 caa_container_of(node, struct buffer_reg_uid, node);
 590
 591         buffer_reg_session_destroy(reg->registry, reg->domain);
 592         free(reg);
 593 }
 594
 595 static void rcu_free_buffer_reg_pid(struct rcu_head *head)
 596 {
 597         struct lttng_ht_node_ulong *node =
 598                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 599         struct buffer_reg_pid *reg =
 600                 caa_container_of(node, struct buffer_reg_pid, node);
 601
 602         buffer_reg_session_destroy(reg->registry, LTTNG_DOMAIN_UST);
 603         free(reg);
 604 }
 605
 606 /*
 607  * Destroy buffer registry per UID. The given pointer is NOT removed from any
 608  * list or hash table. Use buffer_reg_pid_remove() before calling this function
 609  * for the case that the object is in the global hash table.
 610  */
 611 void buffer_reg_uid_destroy(struct buffer_reg_uid *regp,
 612                 struct consumer_output *consumer)
 613 {
 614         struct consumer_socket *socket;
 615
 616         if (!regp) {
 617                 return;
 618         }
 619
 620         DBG3("Buffer registry per UID destroy with id: %d, ABI: %u, uid: %d",
 621                         regp->session_id, regp->bits_per_long, regp->uid);
 622
 623         if (!consumer) {
 624                 goto destroy;
 625         }
 626
 627         rcu_read_lock();
 628         /* Get the right socket from the consumer object. */
 629         socket = consumer_find_socket_by_bitness(regp->bits_per_long,
 630                         consumer);
 631         if (!socket) {
 632                 goto unlock;
 633         }
 634
 635         switch (regp->domain) {
 636         case LTTNG_DOMAIN_UST:
 637                 if (regp->registry->reg.ust->metadata_key) {
 638                         /* Return value does not matter. This call will print errors. */
 639                         (void) consumer_close_metadata(socket,
 640                                         regp->registry->reg.ust->metadata_key);
 641                 }
 642                 break;
 643         default:
 644                 assert(0);
 645                 rcu_read_unlock();
 646                 return;
 647         }
 648
 649 unlock:
 650         rcu_read_unlock();
 651 destroy:
 652         call_rcu(&regp->node.head, rcu_free_buffer_reg_uid);
 653 }
 654
 655 /*
 656  * Remove buffer registry UID object from the global hash table. RCU read side
 657  * lock MUST be acquired before calling this.
 658  */
 659 void buffer_reg_pid_remove(struct buffer_reg_pid *regp)
 660 {
 661         int ret;
 662         struct lttng_ht_iter iter;
 663
 664         assert(regp);
 665
 666         iter.iter.node = &regp->node.node;
 667         ret = lttng_ht_del(buffer_registry_pid, &iter);
 668         assert(!ret);
 669 }
 670
 671 /*
 672  * Destroy buffer registry per PID. The pointer is NOT removed from the global
 673  * hash table. Call buffer_reg_pid_remove() before that if the object was
 674  * previously added to the global hash table.
 675  */
 676 void buffer_reg_pid_destroy(struct buffer_reg_pid *regp)
 677 {
 678         if (!regp) {
 679                 return;
 680         }
 681
 682         DBG3("Buffer registry per PID destroy with id: %d", regp->session_id);
 683
 684         /* This registry is only used by UST. */
 685         call_rcu(&regp->node.head, rcu_free_buffer_reg_pid);
 686 }
 687
 688 /*
 689  * Destroy per PID and UID registry hash table.
 690  *
 691  * Should *NOT* be called with RCU read-side lock held.
 692  */
 693 void buffer_reg_destroy_registries(void)
 694 {
 695         DBG3("Buffer registry destroy all registry");
 696         ht_cleanup_push(buffer_registry_uid);
 697         ht_cleanup_push(buffer_registry_pid);
 698 }