| 1 | /* |
| 2 | * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca> |
| 3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License, version 2 only, |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <assert.h> |
| 21 | #include <poll.h> |
| 22 | #include <pthread.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <sys/mman.h> |
| 26 | #include <sys/socket.h> |
| 27 | #include <sys/stat.h> |
| 28 | #include <sys/types.h> |
| 29 | #include <unistd.h> |
| 30 | #include <lttng/ust-ctl.h> |
| 31 | |
| 32 | #include <common/common.h> |
| 33 | #include <common/sessiond-comm/sessiond-comm.h> |
| 34 | #include <common/relayd/relayd.h> |
| 35 | #include <common/compat/fcntl.h> |
| 36 | |
| 37 | #include "ust-consumer.h" |
| 38 | |
| 39 | extern struct lttng_consumer_global_data consumer_data; |
| 40 | extern int consumer_poll_timeout; |
| 41 | extern volatile int consumer_quit; |
| 42 | |
| 43 | /* |
| 44 | * Mmap the ring buffer, read it and write the data to the tracefile. |
| 45 | * |
| 46 | * Returns the number of bytes written, else negative value on error. |
| 47 | */ |
| 48 | ssize_t lttng_ustconsumer_on_read_subbuffer_mmap( |
| 49 | struct lttng_consumer_local_data *ctx, |
| 50 | struct lttng_consumer_stream *stream, unsigned long len) |
| 51 | { |
| 52 | unsigned long mmap_offset; |
| 53 | long ret = 0, written = 0; |
| 54 | off_t orig_offset = stream->out_fd_offset; |
| 55 | int outfd = stream->out_fd; |
| 56 | uint64_t metadata_id; |
| 57 | struct consumer_relayd_sock_pair *relayd = NULL; |
| 58 | |
| 59 | /* RCU lock for the relayd pointer */ |
| 60 | rcu_read_lock(); |
| 61 | |
| 62 | /* Flag that the current stream if set for network streaming. */ |
| 63 | if (stream->net_seq_idx != -1) { |
| 64 | relayd = consumer_find_relayd(stream->net_seq_idx); |
| 65 | if (relayd == NULL) { |
| 66 | ERR("Cannot find relay for network stream\n"); |
| 67 | goto end; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | /* get the offset inside the fd to mmap */ |
| 72 | ret = ustctl_get_mmap_read_offset(stream->chan->handle, |
| 73 | stream->buf, &mmap_offset); |
| 74 | if (ret != 0) { |
| 75 | errno = -ret; |
| 76 | PERROR("ustctl_get_mmap_read_offset"); |
| 77 | written = ret; |
| 78 | goto end; |
| 79 | } |
| 80 | |
| 81 | /* Handle stream on the relayd if the output is on the network */ |
| 82 | if (relayd) { |
| 83 | if (stream->metadata_flag) { |
| 84 | /* Only lock if metadata since we use the control socket. */ |
| 85 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 86 | } |
| 87 | |
| 88 | ret = consumer_handle_stream_before_relayd(stream, len); |
| 89 | if (ret >= 0) { |
| 90 | outfd = ret; |
| 91 | |
| 92 | /* Write metadata stream id before payload */ |
| 93 | if (stream->metadata_flag) { |
| 94 | metadata_id = htobe64(stream->relayd_stream_id); |
| 95 | do { |
| 96 | ret = write(outfd, (void *) &metadata_id, |
| 97 | sizeof(stream->relayd_stream_id)); |
| 98 | } while (ret < 0 && errno == EINTR); |
| 99 | if (ret < 0) { |
| 100 | PERROR("write metadata stream id"); |
| 101 | written = ret; |
| 102 | goto end; |
| 103 | } |
| 104 | DBG("Metadata stream id %zu written before data", |
| 105 | stream->relayd_stream_id); |
| 106 | } |
| 107 | } |
| 108 | /* Else, use the default set before which is the filesystem. */ |
| 109 | } |
| 110 | |
| 111 | while (len > 0) { |
| 112 | do { |
| 113 | ret = write(outfd, stream->mmap_base + mmap_offset, len); |
| 114 | } while (ret < 0 && errno == EINTR); |
| 115 | if (ret < 0) { |
| 116 | PERROR("Error in file write"); |
| 117 | if (written == 0) { |
| 118 | written = ret; |
| 119 | } |
| 120 | goto end; |
| 121 | } else if (ret > len) { |
| 122 | PERROR("ret %ld > len %lu", ret, len); |
| 123 | written += ret; |
| 124 | goto end; |
| 125 | } else { |
| 126 | len -= ret; |
| 127 | mmap_offset += ret; |
| 128 | } |
| 129 | DBG("UST mmap write() ret %ld (len %lu)", ret, len); |
| 130 | |
| 131 | /* This call is useless on a socket so better save a syscall. */ |
| 132 | if (!relayd) { |
| 133 | /* This won't block, but will start writeout asynchronously */ |
| 134 | lttng_sync_file_range(outfd, stream->out_fd_offset, ret, |
| 135 | SYNC_FILE_RANGE_WRITE); |
| 136 | stream->out_fd_offset += ret; |
| 137 | } |
| 138 | written += ret; |
| 139 | } |
| 140 | lttng_consumer_sync_trace_file(stream, orig_offset); |
| 141 | |
| 142 | end: |
| 143 | if (relayd && stream->metadata_flag) { |
| 144 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 145 | } |
| 146 | rcu_read_unlock(); |
| 147 | return written; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * Splice the data from the ring buffer to the tracefile. |
| 152 | * |
| 153 | * Returns the number of bytes spliced. |
| 154 | */ |
| 155 | ssize_t lttng_ustconsumer_on_read_subbuffer_splice( |
| 156 | struct lttng_consumer_local_data *ctx, |
| 157 | struct lttng_consumer_stream *stream, unsigned long len) |
| 158 | { |
| 159 | return -ENOSYS; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * Take a snapshot for a specific fd |
| 164 | * |
| 165 | * Returns 0 on success, < 0 on error |
| 166 | */ |
| 167 | int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, |
| 168 | struct lttng_consumer_stream *stream) |
| 169 | { |
| 170 | int ret = 0; |
| 171 | |
| 172 | ret = ustctl_snapshot(stream->chan->handle, stream->buf); |
| 173 | if (ret != 0) { |
| 174 | errno = -ret; |
| 175 | PERROR("Getting sub-buffer snapshot."); |
| 176 | } |
| 177 | |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Get the produced position |
| 183 | * |
| 184 | * Returns 0 on success, < 0 on error |
| 185 | */ |
| 186 | int lttng_ustconsumer_get_produced_snapshot( |
| 187 | struct lttng_consumer_local_data *ctx, |
| 188 | struct lttng_consumer_stream *stream, |
| 189 | unsigned long *pos) |
| 190 | { |
| 191 | int ret; |
| 192 | |
| 193 | ret = ustctl_snapshot_get_produced(stream->chan->handle, |
| 194 | stream->buf, pos); |
| 195 | if (ret != 0) { |
| 196 | errno = -ret; |
| 197 | PERROR("kernctl_snapshot_get_produced"); |
| 198 | } |
| 199 | |
| 200 | return ret; |
| 201 | } |
| 202 | |
| 203 | int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
| 204 | int sock, struct pollfd *consumer_sockpoll) |
| 205 | { |
| 206 | ssize_t ret; |
| 207 | struct lttcomm_consumer_msg msg; |
| 208 | |
| 209 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); |
| 210 | if (ret != sizeof(msg)) { |
| 211 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
| 212 | return ret; |
| 213 | } |
| 214 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { |
| 215 | return -ENOENT; |
| 216 | } |
| 217 | |
| 218 | /* relayd need RCU read-side lock */ |
| 219 | rcu_read_lock(); |
| 220 | |
| 221 | switch (msg.cmd_type) { |
| 222 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
| 223 | { |
| 224 | int fd; |
| 225 | struct consumer_relayd_sock_pair *relayd; |
| 226 | |
| 227 | DBG("UST Consumer adding relayd socket"); |
| 228 | |
| 229 | /* Get relayd reference if exists. */ |
| 230 | relayd = consumer_find_relayd(msg.u.relayd_sock.net_index); |
| 231 | if (relayd == NULL) { |
| 232 | /* Not found. Allocate one. */ |
| 233 | relayd = consumer_allocate_relayd_sock_pair( |
| 234 | msg.u.relayd_sock.net_index); |
| 235 | if (relayd == NULL) { |
| 236 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); |
| 237 | goto end_nosignal; |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | /* Poll on consumer socket. */ |
| 242 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 243 | return -EINTR; |
| 244 | } |
| 245 | |
| 246 | /* Get relayd socket from session daemon */ |
| 247 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
| 248 | if (ret != sizeof(fd)) { |
| 249 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
| 250 | goto end_nosignal; |
| 251 | } |
| 252 | |
| 253 | /* Copy socket information and received FD */ |
| 254 | switch (msg.u.relayd_sock.type) { |
| 255 | case LTTNG_STREAM_CONTROL: |
| 256 | /* Copy received lttcomm socket */ |
| 257 | lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock); |
| 258 | ret = lttcomm_create_sock(&relayd->control_sock); |
| 259 | if (ret < 0) { |
| 260 | goto end_nosignal; |
| 261 | } |
| 262 | |
| 263 | /* Close the created socket fd which is useless */ |
| 264 | close(relayd->control_sock.fd); |
| 265 | |
| 266 | /* Assign new file descriptor */ |
| 267 | relayd->control_sock.fd = fd; |
| 268 | break; |
| 269 | case LTTNG_STREAM_DATA: |
| 270 | /* Copy received lttcomm socket */ |
| 271 | lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock); |
| 272 | ret = lttcomm_create_sock(&relayd->data_sock); |
| 273 | if (ret < 0) { |
| 274 | goto end_nosignal; |
| 275 | } |
| 276 | |
| 277 | /* Close the created socket fd which is useless */ |
| 278 | close(relayd->data_sock.fd); |
| 279 | |
| 280 | /* Assign new file descriptor */ |
| 281 | relayd->data_sock.fd = fd; |
| 282 | break; |
| 283 | default: |
| 284 | ERR("Unknown relayd socket type"); |
| 285 | goto end_nosignal; |
| 286 | } |
| 287 | |
| 288 | DBG("Consumer %s socket created successfully with net idx %d (fd: %d)", |
| 289 | msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data", |
| 290 | relayd->net_seq_idx, fd); |
| 291 | |
| 292 | /* |
| 293 | * Add relayd socket pair to consumer data hashtable. If object already |
| 294 | * exists or on error, the function gracefully returns. |
| 295 | */ |
| 296 | consumer_add_relayd(relayd); |
| 297 | |
| 298 | goto end_nosignal; |
| 299 | } |
| 300 | case LTTNG_CONSUMER_ADD_CHANNEL: |
| 301 | { |
| 302 | struct lttng_consumer_channel *new_channel; |
| 303 | int fds[1]; |
| 304 | size_t nb_fd = 1; |
| 305 | |
| 306 | /* block */ |
| 307 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 308 | return -EINTR; |
| 309 | } |
| 310 | ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd); |
| 311 | if (ret != sizeof(fds)) { |
| 312 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
| 313 | return ret; |
| 314 | } |
| 315 | |
| 316 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); |
| 317 | |
| 318 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, |
| 319 | fds[0], -1, |
| 320 | msg.u.channel.mmap_len, |
| 321 | msg.u.channel.max_sb_size); |
| 322 | if (new_channel == NULL) { |
| 323 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); |
| 324 | goto end_nosignal; |
| 325 | } |
| 326 | if (ctx->on_recv_channel != NULL) { |
| 327 | ret = ctx->on_recv_channel(new_channel); |
| 328 | if (ret == 0) { |
| 329 | consumer_add_channel(new_channel); |
| 330 | } else if (ret < 0) { |
| 331 | goto end_nosignal; |
| 332 | } |
| 333 | } else { |
| 334 | consumer_add_channel(new_channel); |
| 335 | } |
| 336 | goto end_nosignal; |
| 337 | } |
| 338 | case LTTNG_CONSUMER_ADD_STREAM: |
| 339 | { |
| 340 | struct lttng_consumer_stream *new_stream; |
| 341 | int fds[2]; |
| 342 | size_t nb_fd = 2; |
| 343 | struct consumer_relayd_sock_pair *relayd = NULL; |
| 344 | |
| 345 | /* block */ |
| 346 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 347 | return -EINTR; |
| 348 | } |
| 349 | ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd); |
| 350 | if (ret != sizeof(fds)) { |
| 351 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
| 352 | return ret; |
| 353 | } |
| 354 | |
| 355 | assert(msg.u.stream.output == LTTNG_EVENT_MMAP); |
| 356 | new_stream = consumer_allocate_stream(msg.u.channel.channel_key, |
| 357 | msg.u.stream.stream_key, |
| 358 | fds[0], fds[1], |
| 359 | msg.u.stream.state, |
| 360 | msg.u.stream.mmap_len, |
| 361 | msg.u.stream.output, |
| 362 | msg.u.stream.path_name, |
| 363 | msg.u.stream.uid, |
| 364 | msg.u.stream.gid, |
| 365 | msg.u.stream.net_index, |
| 366 | msg.u.stream.metadata_flag); |
| 367 | if (new_stream == NULL) { |
| 368 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); |
| 369 | goto end; |
| 370 | } |
| 371 | |
| 372 | /* The stream is not metadata. Get relayd reference if exists. */ |
| 373 | relayd = consumer_find_relayd(msg.u.stream.net_index); |
| 374 | if (relayd != NULL) { |
| 375 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 376 | /* Add stream on the relayd */ |
| 377 | ret = relayd_add_stream(&relayd->control_sock, |
| 378 | msg.u.stream.name, msg.u.stream.path_name, |
| 379 | &new_stream->relayd_stream_id); |
| 380 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 381 | if (ret < 0) { |
| 382 | goto end; |
| 383 | } |
| 384 | } else if (msg.u.stream.net_index != -1) { |
| 385 | ERR("Network sequence index %d unknown. Not adding stream.", |
| 386 | msg.u.stream.net_index); |
| 387 | free(new_stream); |
| 388 | goto end; |
| 389 | } |
| 390 | |
| 391 | if (ctx->on_recv_stream != NULL) { |
| 392 | ret = ctx->on_recv_stream(new_stream); |
| 393 | if (ret == 0) { |
| 394 | consumer_add_stream(new_stream); |
| 395 | } else if (ret < 0) { |
| 396 | goto end; |
| 397 | } |
| 398 | } else { |
| 399 | consumer_add_stream(new_stream); |
| 400 | } |
| 401 | |
| 402 | DBG("UST consumer_add_stream %s (%d,%d) with relayd id %lu", |
| 403 | msg.u.stream.path_name, fds[0], fds[1], |
| 404 | new_stream->relayd_stream_id); |
| 405 | break; |
| 406 | } |
| 407 | case LTTNG_CONSUMER_UPDATE_STREAM: |
| 408 | { |
| 409 | return -ENOSYS; |
| 410 | #if 0 |
| 411 | if (ctx->on_update_stream != NULL) { |
| 412 | ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state); |
| 413 | if (ret == 0) { |
| 414 | consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state); |
| 415 | } else if (ret < 0) { |
| 416 | goto end; |
| 417 | } |
| 418 | } else { |
| 419 | consumer_change_stream_state(msg.u.stream.stream_key, |
| 420 | msg.u.stream.state); |
| 421 | } |
| 422 | #endif |
| 423 | break; |
| 424 | } |
| 425 | default: |
| 426 | break; |
| 427 | } |
| 428 | end: |
| 429 | /* |
| 430 | * Wake-up the other end by writing a null byte in the pipe |
| 431 | * (non-blocking). Important note: Because writing into the |
| 432 | * pipe is non-blocking (and therefore we allow dropping wakeup |
| 433 | * data, as long as there is wakeup data present in the pipe |
| 434 | * buffer to wake up the other end), the other end should |
| 435 | * perform the following sequence for waiting: |
| 436 | * 1) empty the pipe (reads). |
| 437 | * 2) perform update operation. |
| 438 | * 3) wait on the pipe (poll). |
| 439 | */ |
| 440 | do { |
| 441 | ret = write(ctx->consumer_poll_pipe[1], "", 1); |
| 442 | } while (ret < 0 && errno == EINTR); |
| 443 | end_nosignal: |
| 444 | rcu_read_unlock(); |
| 445 | return 0; |
| 446 | } |
| 447 | |
| 448 | int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan) |
| 449 | { |
| 450 | struct lttng_ust_object_data obj; |
| 451 | |
| 452 | obj.handle = -1; |
| 453 | obj.shm_fd = chan->shm_fd; |
| 454 | obj.wait_fd = chan->wait_fd; |
| 455 | obj.memory_map_size = chan->mmap_len; |
| 456 | chan->handle = ustctl_map_channel(&obj); |
| 457 | if (!chan->handle) { |
| 458 | return -ENOMEM; |
| 459 | } |
| 460 | chan->wait_fd_is_copy = 1; |
| 461 | chan->shm_fd = -1; |
| 462 | |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream) |
| 467 | { |
| 468 | ustctl_flush_buffer(stream->chan->handle, stream->buf, 0); |
| 469 | stream->hangup_flush_done = 1; |
| 470 | } |
| 471 | |
| 472 | void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan) |
| 473 | { |
| 474 | ustctl_unmap_channel(chan->handle); |
| 475 | } |
| 476 | |
| 477 | int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream) |
| 478 | { |
| 479 | struct lttng_ust_object_data obj; |
| 480 | int ret; |
| 481 | |
| 482 | obj.handle = -1; |
| 483 | obj.shm_fd = stream->shm_fd; |
| 484 | obj.wait_fd = stream->wait_fd; |
| 485 | obj.memory_map_size = stream->mmap_len; |
| 486 | ret = ustctl_add_stream(stream->chan->handle, &obj); |
| 487 | if (ret) |
| 488 | return ret; |
| 489 | stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu); |
| 490 | if (!stream->buf) |
| 491 | return -EBUSY; |
| 492 | /* ustctl_open_stream_read has closed the shm fd. */ |
| 493 | stream->wait_fd_is_copy = 1; |
| 494 | stream->shm_fd = -1; |
| 495 | |
| 496 | stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf); |
| 497 | if (!stream->mmap_base) { |
| 498 | return -EINVAL; |
| 499 | } |
| 500 | |
| 501 | return 0; |
| 502 | } |
| 503 | |
| 504 | void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream) |
| 505 | { |
| 506 | ustctl_close_stream_read(stream->chan->handle, stream->buf); |
| 507 | } |
| 508 | |
| 509 | |
| 510 | int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 511 | struct lttng_consumer_local_data *ctx) |
| 512 | { |
| 513 | unsigned long len; |
| 514 | int err; |
| 515 | long ret = 0; |
| 516 | struct lttng_ust_shm_handle *handle; |
| 517 | struct lttng_ust_lib_ring_buffer *buf; |
| 518 | char dummy; |
| 519 | ssize_t readlen; |
| 520 | |
| 521 | DBG("In read_subbuffer (wait_fd: %d, stream key: %d)", |
| 522 | stream->wait_fd, stream->key); |
| 523 | |
| 524 | /* We can consume the 1 byte written into the wait_fd by UST */ |
| 525 | if (!stream->hangup_flush_done) { |
| 526 | do { |
| 527 | readlen = read(stream->wait_fd, &dummy, 1); |
| 528 | } while (readlen == -1 && errno == EINTR); |
| 529 | if (readlen == -1) { |
| 530 | ret = readlen; |
| 531 | goto end; |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | buf = stream->buf; |
| 536 | handle = stream->chan->handle; |
| 537 | /* Get the next subbuffer */ |
| 538 | err = ustctl_get_next_subbuf(handle, buf); |
| 539 | if (err != 0) { |
| 540 | ret = -ret; /* ustctl_get_next_subbuf returns negative, caller expect positive. */ |
| 541 | /* |
| 542 | * This is a debug message even for single-threaded consumer, |
| 543 | * because poll() have more relaxed criterions than get subbuf, |
| 544 | * so get_subbuf may fail for short race windows where poll() |
| 545 | * would issue wakeups. |
| 546 | */ |
| 547 | DBG("Reserving sub buffer failed (everything is normal, " |
| 548 | "it is due to concurrency)"); |
| 549 | goto end; |
| 550 | } |
| 551 | assert(stream->output == LTTNG_EVENT_MMAP); |
| 552 | /* read the used subbuffer size */ |
| 553 | err = ustctl_get_padded_subbuf_size(handle, buf, &len); |
| 554 | assert(err == 0); |
| 555 | /* write the subbuffer to the tracefile */ |
| 556 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); |
| 557 | if (ret != len) { |
| 558 | /* |
| 559 | * display the error but continue processing to try |
| 560 | * to release the subbuffer |
| 561 | */ |
| 562 | ERR("Error writing to tracefile"); |
| 563 | } |
| 564 | err = ustctl_put_next_subbuf(handle, buf); |
| 565 | assert(err == 0); |
| 566 | end: |
| 567 | return ret; |
| 568 | } |
| 569 | |
| 570 | int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream) |
| 571 | { |
| 572 | int ret; |
| 573 | |
| 574 | /* Opening the tracefile in write mode */ |
| 575 | if (stream->path_name != NULL && stream->net_seq_idx == -1) { |
| 576 | ret = run_as_open(stream->path_name, |
| 577 | O_WRONLY|O_CREAT|O_TRUNC, |
| 578 | S_IRWXU|S_IRWXG|S_IRWXO, |
| 579 | stream->uid, stream->gid); |
| 580 | if (ret < 0) { |
| 581 | ERR("Opening %s", stream->path_name); |
| 582 | PERROR("open"); |
| 583 | goto error; |
| 584 | } |
| 585 | stream->out_fd = ret; |
| 586 | } |
| 587 | |
| 588 | /* we return 0 to let the library handle the FD internally */ |
| 589 | return 0; |
| 590 | |
| 591 | error: |
| 592 | return ret; |
| 593 | } |