X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=67f60d816c0de6c31407840f5f2b2b160e049f1b;hp=9abee1de8ad5d3bb01efdf2b04ada6270811de18;hb=6f9449c22eef59294cf1e1dc3610a5cbf14baec0;hpb=d14d33bf091e72b23b1f90ea18a0a01bed098b76 diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c index 9abee1de8..e06f3b3e0 100644 --- a/src/common/kernel-consumer/kernel-consumer.c +++ b/src/common/kernel-consumer/kernel-consumer.c @@ -1,22 +1,13 @@ /* - * Copyright (C) 2011 - Julien Desfossez - * Mathieu Desnoyers + * Copyright (C) 2011 Julien Desfossez + * Copyright (C) 2011 Mathieu Desnoyers + * Copyright (C) 2017 Jérémie Galarneau * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License, version 2 only, - * as published by the Free Software Foundation. + * SPDX-License-Identifier: GPL-2.0-only * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#define _GNU_SOURCE +#define _LGPL_SOURCE #include #include #include @@ -25,420 +16,1678 @@ #include #include #include +#include #include #include +#include #include #include #include +#include #include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include #include "kernel-consumer.h" extern struct lttng_consumer_global_data consumer_data; extern int consumer_poll_timeout; -extern volatile int consumer_quit; /* - * Mmap the ring buffer, read it and write the data to the tracefile. + * Take a snapshot for a specific fd * - * Returns the number of bytes written + * Returns 0 on success, < 0 on error */ -ssize_t lttng_kconsumer_on_read_subbuffer_mmap( - struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, unsigned long len) +int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream) { - unsigned long mmap_offset; - ssize_t ret = 0; - off_t orig_offset = stream->out_fd_offset; - int fd = stream->wait_fd; - int outfd = stream->out_fd; - - /* get the offset inside the fd to mmap */ - ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); - if (ret != 0) { - errno = -ret; - perror("kernctl_get_mmap_read_offset"); - goto end; - } + int ret = 0; + int infd = stream->wait_fd; - while (len > 0) { - ret = write(outfd, stream->mmap_base + mmap_offset, len); - if (ret >= len) { - len = 0; - } else if (ret < 0) { - errno = -ret; - perror("Error in file write"); - goto end; - } - /* This won't block, but will start writeout asynchronously */ - lttng_sync_file_range(outfd, stream->out_fd_offset, ret, - SYNC_FILE_RANGE_WRITE); - stream->out_fd_offset += ret; + ret = kernctl_snapshot(infd); + /* + * -EAGAIN is not an error, it just means that there is no data to + * be read. + */ + if (ret != 0 && ret != -EAGAIN) { + PERROR("Getting sub-buffer snapshot."); } - lttng_consumer_sync_trace_file(stream, orig_offset); - - goto end; - -end: return ret; } /* - * Splice the data from the ring buffer to the tracefile. + * Sample consumed and produced positions for a specific fd. * - * Returns the number of bytes spliced. + * Returns 0 on success, < 0 on error. */ -ssize_t lttng_kconsumer_on_read_subbuffer_splice( - struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, unsigned long len) +int lttng_kconsumer_sample_snapshot_positions( + struct lttng_consumer_stream *stream) { - ssize_t ret = 0; - loff_t offset = 0; - off_t orig_offset = stream->out_fd_offset; - int fd = stream->wait_fd; - int outfd = stream->out_fd; - - while (len > 0) { - DBG("splice chan to pipe offset %lu (fd : %d)", - (unsigned long)offset, fd); - ret = splice(fd, &offset, ctx->consumer_thread_pipe[1], NULL, len, - SPLICE_F_MOVE | SPLICE_F_MORE); - DBG("splice chan to pipe ret %zd", ret); - if (ret < 0) { - errno = -ret; - perror("Error in relay splice"); - goto splice_error; - } - - ret = splice(ctx->consumer_thread_pipe[0], NULL, outfd, NULL, ret, - SPLICE_F_MOVE | SPLICE_F_MORE); - DBG("splice pipe to file %zd", ret); - if (ret < 0) { - errno = -ret; - perror("Error in file splice"); - goto splice_error; - } - len -= ret; - /* This won't block, but will start writeout asynchronously */ - lttng_sync_file_range(outfd, stream->out_fd_offset, ret, - SYNC_FILE_RANGE_WRITE); - stream->out_fd_offset += ret; - } - lttng_consumer_sync_trace_file(stream, orig_offset); - - goto end; - -splice_error: - /* send the appropriate error description to sessiond */ - switch(ret) { - case EBADF: - lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EBADF); - break; - case EINVAL: - lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EINVAL); - break; - case ENOMEM: - lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ENOMEM); - break; - case ESPIPE: - lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ESPIPE); - break; - } + assert(stream); -end: - return ret; + return kernctl_snapshot_sample_positions(stream->wait_fd); } /* - * Take a snapshot for a specific fd + * Get the produced position * * Returns 0 on success, < 0 on error */ -int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream) +int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream, + unsigned long *pos) { - int ret = 0; + int ret; int infd = stream->wait_fd; - ret = kernctl_snapshot(infd); + ret = kernctl_snapshot_get_produced(infd, pos); if (ret != 0) { - errno = -ret; - perror("Getting sub-buffer snapshot."); + PERROR("kernctl_snapshot_get_produced"); } return ret; } /* - * Get the produced position + * Get the consumerd position * * Returns 0 on success, < 0 on error */ -int lttng_kconsumer_get_produced_snapshot( - struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, +int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream *stream, unsigned long *pos) { int ret; int infd = stream->wait_fd; - ret = kernctl_snapshot_get_produced(infd, pos); + ret = kernctl_snapshot_get_consumed(infd, pos); if (ret != 0) { - errno = -ret; - perror("kernctl_snapshot_get_produced"); + PERROR("kernctl_snapshot_get_consumed"); } return ret; } -int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, - int sock, struct pollfd *consumer_sockpoll) +static +int get_current_subbuf_addr(struct lttng_consumer_stream *stream, + const char **addr) { - ssize_t ret; - struct lttcomm_consumer_msg msg; + int ret; + unsigned long mmap_offset; + const char *mmap_base = stream->mmap_base; - ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); - if (ret != sizeof(msg)) { - lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_CMD); - return ret; + ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset); + if (ret < 0) { + PERROR("Failed to get mmap read offset"); + goto error; } - if (msg.cmd_type == LTTNG_CONSUMER_STOP) { - return -ENOENT; + + *addr = mmap_base + mmap_offset; +error: + return ret; +} + +/* + * Take a snapshot of all the stream of a channel + * RCU read-side lock must be held across this function to ensure existence of + * channel. The channel lock must be held by the caller. + * + * Returns 0 on success, < 0 on error + */ +static int lttng_kconsumer_snapshot_channel( + struct lttng_consumer_channel *channel, + uint64_t key, char *path, uint64_t relayd_id, + uint64_t nb_packets_per_stream, + struct lttng_consumer_local_data *ctx) +{ + int ret; + struct lttng_consumer_stream *stream; + + DBG("Kernel consumer snapshot channel %" PRIu64, key); + + rcu_read_lock(); + + /* Splice is not supported yet for channel snapshot. */ + if (channel->output != CONSUMER_CHANNEL_MMAP) { + ERR("Unsupported output type for channel \"%s\": mmap output is required to record a snapshot", + channel->name); + ret = -1; + goto end; } - switch (msg.cmd_type) { - case LTTNG_CONSUMER_ADD_CHANNEL: - { - struct lttng_consumer_channel *new_channel; + cds_list_for_each_entry(stream, &channel->streams.head, send_node) { + unsigned long consumed_pos, produced_pos; - DBG("consumer_add_channel %d", msg.u.channel.channel_key); - new_channel = consumer_allocate_channel(msg.u.channel.channel_key, - -1, -1, - msg.u.channel.mmap_len, - msg.u.channel.max_sb_size); - if (new_channel == NULL) { - lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); - goto end_nosignal; + health_code_update(); + + /* + * Lock stream because we are about to change its state. + */ + pthread_mutex_lock(&stream->lock); + + assert(channel->trace_chunk); + if (!lttng_trace_chunk_get(channel->trace_chunk)) { + /* + * Can't happen barring an internal error as the channel + * holds a reference to the trace chunk. + */ + ERR("Failed to acquire reference to channel's trace chunk"); + ret = -1; + goto end_unlock; } - if (ctx->on_recv_channel != NULL) { - ret = ctx->on_recv_channel(new_channel); - if (ret == 0) { - consumer_add_channel(new_channel); - } else if (ret < 0) { - goto end_nosignal; + assert(!stream->trace_chunk); + stream->trace_chunk = channel->trace_chunk; + + /* + * Assign the received relayd ID so we can use it for streaming. The streams + * are not visible to anyone so this is OK to change it. + */ + stream->net_seq_idx = relayd_id; + channel->relayd_id = relayd_id; + if (relayd_id != (uint64_t) -1ULL) { + ret = consumer_send_relayd_stream(stream, path); + if (ret < 0) { + ERR("sending stream to relayd"); + goto end_unlock; } } else { - consumer_add_channel(new_channel); + ret = consumer_stream_create_output_files(stream, + false); + if (ret < 0) { + goto end_unlock; + } + DBG("Kernel consumer snapshot stream (%" PRIu64 ")", + stream->key); } - goto end_nosignal; - } - case LTTNG_CONSUMER_ADD_STREAM: - { - struct lttng_consumer_stream *new_stream; - int fd; - /* block */ - if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { - return -EINTR; + ret = kernctl_buffer_flush_empty(stream->wait_fd); + if (ret < 0) { + /* + * Doing a buffer flush which does not take into + * account empty packets. This is not perfect + * for stream intersection, but required as a + * fall-back when "flush_empty" is not + * implemented by lttng-modules. + */ + ret = kernctl_buffer_flush(stream->wait_fd); + if (ret < 0) { + ERR("Failed to flush kernel stream"); + goto end_unlock; + } + goto end_unlock; } - ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); - if (ret != sizeof(fd)) { - lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); - return ret; - } - - DBG("consumer_add_stream %s (%d)", msg.u.stream.path_name, - fd); - new_stream = consumer_allocate_stream(msg.u.stream.channel_key, - msg.u.stream.stream_key, - fd, fd, - msg.u.stream.state, - msg.u.stream.mmap_len, - msg.u.stream.output, - msg.u.stream.path_name, - msg.u.stream.uid, - msg.u.stream.gid); - if (new_stream == NULL) { - lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); - goto end; + + ret = lttng_kconsumer_take_snapshot(stream); + if (ret < 0) { + ERR("Taking kernel snapshot"); + goto end_unlock; } - if (ctx->on_recv_stream != NULL) { - ret = ctx->on_recv_stream(new_stream); - if (ret == 0) { - consumer_add_stream(new_stream); - } else if (ret < 0) { - goto end; + + ret = lttng_kconsumer_get_produced_snapshot(stream, &produced_pos); + if (ret < 0) { + ERR("Produced kernel snapshot position"); + goto end_unlock; + } + + ret = lttng_kconsumer_get_consumed_snapshot(stream, &consumed_pos); + if (ret < 0) { + ERR("Consumerd kernel snapshot position"); + goto end_unlock; + } + + consumed_pos = consumer_get_consume_start_pos(consumed_pos, + produced_pos, nb_packets_per_stream, + stream->max_sb_size); + + while ((long) (consumed_pos - produced_pos) < 0) { + ssize_t read_len; + unsigned long len, padded_len; + const char *subbuf_addr; + struct lttng_buffer_view subbuf_view; + + health_code_update(); + DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos); + + ret = kernctl_get_subbuf(stream->wait_fd, &consumed_pos); + if (ret < 0) { + if (ret != -EAGAIN) { + PERROR("kernctl_get_subbuf snapshot"); + goto end_unlock; + } + DBG("Kernel consumer get subbuf failed. Skipping it."); + consumed_pos += stream->max_sb_size; + stream->chan->lost_packets++; + continue; } - } else { - consumer_add_stream(new_stream); + + ret = kernctl_get_subbuf_size(stream->wait_fd, &len); + if (ret < 0) { + ERR("Snapshot kernctl_get_subbuf_size"); + goto error_put_subbuf; + } + + ret = kernctl_get_padded_subbuf_size(stream->wait_fd, &padded_len); + if (ret < 0) { + ERR("Snapshot kernctl_get_padded_subbuf_size"); + goto error_put_subbuf; + } + + ret = get_current_subbuf_addr(stream, &subbuf_addr); + if (ret) { + goto error_put_subbuf; + } + + subbuf_view = lttng_buffer_view_init( + subbuf_addr, 0, padded_len); + read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, + stream, &subbuf_view, + padded_len - len); + /* + * We write the padded len in local tracefiles but the data len + * when using a relay. Display the error but continue processing + * to try to release the subbuffer. + */ + if (relayd_id != (uint64_t) -1ULL) { + if (read_len != len) { + ERR("Error sending to the relay (ret: %zd != len: %lu)", + read_len, len); + } + } else { + if (read_len != padded_len) { + ERR("Error writing to tracefile (ret: %zd != len: %lu)", + read_len, padded_len); + } + } + + ret = kernctl_put_subbuf(stream->wait_fd); + if (ret < 0) { + ERR("Snapshot kernctl_put_subbuf"); + goto end_unlock; + } + consumed_pos += stream->max_sb_size; } - break; - } - case LTTNG_CONSUMER_UPDATE_STREAM: - { - if (ctx->on_update_stream != NULL) { - ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state); - if (ret == 0) { - consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state); - } else if (ret < 0) { - goto end; + + if (relayd_id == (uint64_t) -1ULL) { + if (stream->out_fd >= 0) { + ret = close(stream->out_fd); + if (ret < 0) { + PERROR("Kernel consumer snapshot close out_fd"); + goto end_unlock; + } + stream->out_fd = -1; } } else { - consumer_change_stream_state(msg.u.stream.stream_key, - msg.u.stream.state); + close_relayd_stream(stream); + stream->net_seq_idx = (uint64_t) -1ULL; } - break; - } - default: - break; + lttng_trace_chunk_put(stream->trace_chunk); + stream->trace_chunk = NULL; + pthread_mutex_unlock(&stream->lock); } -end: - /* signal the poll thread */ - ret = write(ctx->consumer_poll_pipe[1], "4", 1); + + /* All good! */ + ret = 0; + goto end; + +error_put_subbuf: + ret = kernctl_put_subbuf(stream->wait_fd); if (ret < 0) { - perror("write consumer poll"); + ERR("Snapshot kernctl_put_subbuf error path"); } -end_nosignal: - return 0; +end_unlock: + pthread_mutex_unlock(&stream->lock); +end: + rcu_read_unlock(); + return ret; } /* - * Consume data on a file descriptor and write it on a trace file. + * Read the whole metadata available for a snapshot. + * RCU read-side lock must be held across this function to ensure existence of + * metadata_channel. The channel lock must be held by the caller. + * + * Returns 0 on success, < 0 on error */ -ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, +static int lttng_kconsumer_snapshot_metadata( + struct lttng_consumer_channel *metadata_channel, + uint64_t key, char *path, uint64_t relayd_id, struct lttng_consumer_local_data *ctx) { - unsigned long len; - int err; - ssize_t ret = 0; - int infd = stream->wait_fd; + int ret, use_relayd = 0; + ssize_t ret_read; + struct lttng_consumer_stream *metadata_stream; - DBG("In read_subbuffer (infd : %d)", infd); - /* Get the next subbuffer */ - err = kernctl_get_next_subbuf(infd); - if (err != 0) { - /* - * This is a debug message even for single-threaded consumer, - * because poll() have more relaxed criterions than get subbuf, - * so get_subbuf may fail for short race windows where poll() - * would issue wakeups. - */ - DBG("Reserving sub buffer failed (everything is normal, " - "it is due to concurrency)"); - goto end; + assert(ctx); + + DBG("Kernel consumer snapshot metadata with key %" PRIu64 " at path %s", + key, path); + + rcu_read_lock(); + + metadata_stream = metadata_channel->metadata_stream; + assert(metadata_stream); + + pthread_mutex_lock(&metadata_stream->lock); + assert(metadata_channel->trace_chunk); + assert(metadata_stream->trace_chunk); + + /* Flag once that we have a valid relayd for the stream. */ + if (relayd_id != (uint64_t) -1ULL) { + use_relayd = 1; } - switch (stream->output) { - case LTTNG_EVENT_SPLICE: - /* read the whole subbuffer */ - err = kernctl_get_padded_subbuf_size(infd, &len); - if (err != 0) { - errno = -ret; - perror("Getting sub-buffer len failed."); - goto end; - } + if (use_relayd) { + ret = consumer_send_relayd_stream(metadata_stream, path); + if (ret < 0) { + goto error_snapshot; + } + } else { + ret = consumer_stream_create_output_files(metadata_stream, + false); + if (ret < 0) { + goto error_snapshot; + } + } - /* splice the subbuffer to the tracefile */ - ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len); - if (ret < 0) { - /* - * display the error but continue processing to try - * to release the subbuffer - */ - ERR("Error splicing to tracefile"); - } - break; - case LTTNG_EVENT_MMAP: - /* read the used subbuffer size */ - err = kernctl_get_padded_subbuf_size(infd, &len); - if (err != 0) { - errno = -ret; - perror("Getting sub-buffer len failed."); - goto end; + do { + health_code_update(); + + ret_read = lttng_consumer_read_subbuffer(metadata_stream, ctx, true); + if (ret_read < 0) { + if (ret_read != -EAGAIN) { + ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)", + ret_read); + ret = ret_read; + goto error_snapshot; } - /* write the subbuffer to the tracefile */ - ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); + /* ret_read is negative at this point so we will exit the loop. */ + continue; + } + } while (ret_read >= 0); + + if (use_relayd) { + close_relayd_stream(metadata_stream); + metadata_stream->net_seq_idx = (uint64_t) -1ULL; + } else { + if (metadata_stream->out_fd >= 0) { + ret = close(metadata_stream->out_fd); if (ret < 0) { + PERROR("Kernel consumer snapshot metadata close out_fd"); /* - * display the error but continue processing to try - * to release the subbuffer + * Don't go on error here since the snapshot was successful at this + * point but somehow the close failed. */ - ERR("Error writing to tracefile"); } - break; - default: - ERR("Unknown output method"); - ret = -1; - } - - err = kernctl_put_next_subbuf(infd); - if (err != 0) { - errno = -ret; - if (errno == EFAULT) { - perror("Error in unreserving sub buffer\n"); - } else if (errno == EIO) { - /* Should never happen with newer LTTng versions */ - perror("Reader has been pushed by the writer, last sub-buffer corrupted."); + metadata_stream->out_fd = -1; + lttng_trace_chunk_put(metadata_stream->trace_chunk); + metadata_stream->trace_chunk = NULL; } - goto end; } -end: + ret = 0; +error_snapshot: + pthread_mutex_unlock(&metadata_stream->lock); + cds_list_del(&metadata_stream->send_node); + consumer_stream_destroy(metadata_stream, NULL); + metadata_channel->metadata_stream = NULL; + rcu_read_unlock(); return ret; } -int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) +/* + * Receive command from session daemon and process it. + * + * Return 1 on success else a negative value or 0. + */ +int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, + int sock, struct pollfd *consumer_sockpoll) { - int ret; + ssize_t ret; + enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; + struct lttcomm_consumer_msg msg; - /* Opening the tracefile in write mode */ - if (stream->path_name != NULL) { - ret = run_as_open(stream->path_name, - O_WRONLY|O_CREAT|O_TRUNC, - S_IRWXU|S_IRWXG|S_IRWXO, - stream->uid, stream->gid); - if (ret < 0) { - ERR("Opening %s", stream->path_name); - perror("open"); - goto error; + health_code_update(); + + ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); + if (ret != sizeof(msg)) { + if (ret > 0) { + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD); + ret = -1; } - stream->out_fd = ret; + return ret; } - if (stream->output == LTTNG_EVENT_MMAP) { - /* get the len of the mmap region */ - unsigned long mmap_len; + health_code_update(); - ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); - if (ret != 0) { - errno = -ret; - perror("kernctl_get_mmap_len"); - goto error_close_fd; + /* Deprecated command */ + assert(msg.cmd_type != LTTNG_CONSUMER_STOP); + + health_code_update(); + + /* relayd needs RCU read-side protection */ + rcu_read_lock(); + + switch (msg.cmd_type) { + case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: + { + /* Session daemon status message are handled in the following call. */ + consumer_add_relayd_socket(msg.u.relayd_sock.net_index, + msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll, + &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id, + msg.u.relayd_sock.relayd_session_id); + goto end_nosignal; + } + case LTTNG_CONSUMER_ADD_CHANNEL: + { + struct lttng_consumer_channel *new_channel; + int ret_recv; + const uint64_t chunk_id = msg.u.channel.chunk_id.value; + + health_code_update(); + + /* First send a status message before receiving the fds. */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto error_fatal; } - stream->mmap_len = (size_t) mmap_len; - stream->mmap_base = mmap(NULL, stream->mmap_len, - PROT_READ, MAP_PRIVATE, stream->wait_fd, 0); - if (stream->mmap_base == MAP_FAILED) { - perror("Error mmaping"); - ret = -1; - goto error_close_fd; + health_code_update(); + + DBG("consumer_add_channel %" PRIu64, msg.u.channel.channel_key); + new_channel = consumer_allocate_channel(msg.u.channel.channel_key, + msg.u.channel.session_id, + msg.u.channel.chunk_id.is_set ? + &chunk_id : NULL, + msg.u.channel.pathname, + msg.u.channel.name, + msg.u.channel.relayd_id, msg.u.channel.output, + msg.u.channel.tracefile_size, + msg.u.channel.tracefile_count, 0, + msg.u.channel.monitor, + msg.u.channel.live_timer_interval, + msg.u.channel.is_live, + NULL, NULL); + if (new_channel == NULL) { + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); + goto end_nosignal; + } + new_channel->nb_init_stream_left = msg.u.channel.nb_init_streams; + switch (msg.u.channel.output) { + case LTTNG_EVENT_SPLICE: + new_channel->output = CONSUMER_CHANNEL_SPLICE; + break; + case LTTNG_EVENT_MMAP: + new_channel->output = CONSUMER_CHANNEL_MMAP; + break; + default: + ERR("Channel output unknown %d", msg.u.channel.output); + goto end_nosignal; } - } - /* we return 0 to let the library handle the FD internally */ - return 0; + /* Translate and save channel type. */ + switch (msg.u.channel.type) { + case CONSUMER_CHANNEL_TYPE_DATA: + case CONSUMER_CHANNEL_TYPE_METADATA: + new_channel->type = msg.u.channel.type; + break; + default: + assert(0); + goto end_nosignal; + }; -error_close_fd: - { - int err; + health_code_update(); - err = close(stream->out_fd); - assert(!err); - } -error: - return ret; -} + if (ctx->on_recv_channel != NULL) { + ret_recv = ctx->on_recv_channel(new_channel); + if (ret_recv == 0) { + ret = consumer_add_channel(new_channel, ctx); + } else if (ret_recv < 0) { + goto end_nosignal; + } + } else { + ret = consumer_add_channel(new_channel, ctx); + } + if (msg.u.channel.type == CONSUMER_CHANNEL_TYPE_DATA && !ret) { + int monitor_start_ret; + + DBG("Consumer starting monitor timer"); + consumer_timer_live_start(new_channel, + msg.u.channel.live_timer_interval); + monitor_start_ret = consumer_timer_monitor_start( + new_channel, + msg.u.channel.monitor_timer_interval); + if (monitor_start_ret < 0) { + ERR("Starting channel monitoring timer failed"); + goto end_nosignal; + } + } + + health_code_update(); + + /* If we received an error in add_channel, we need to report it. */ + if (ret < 0) { + ret = consumer_send_status_msg(sock, ret); + if (ret < 0) { + goto error_fatal; + } + goto end_nosignal; + } + + goto end_nosignal; + } + case LTTNG_CONSUMER_ADD_STREAM: + { + int fd; + struct lttng_pipe *stream_pipe; + struct lttng_consumer_stream *new_stream; + struct lttng_consumer_channel *channel; + int alloc_ret = 0; + + /* + * Get stream's channel reference. Needed when adding the stream to the + * global hash table. + */ + channel = consumer_find_channel(msg.u.stream.channel_key); + if (!channel) { + /* + * We could not find the channel. Can happen if cpu hotplug + * happens while tearing down. + */ + ERR("Unable to find channel key %" PRIu64, msg.u.stream.channel_key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } + + health_code_update(); + + /* First send a status message before receiving the fds. */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto error_add_stream_fatal; + } + + health_code_update(); + + if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) { + /* Channel was not found. */ + goto error_add_stream_nosignal; + } + + /* Blocking call */ + health_poll_entry(); + ret = lttng_consumer_poll_socket(consumer_sockpoll); + health_poll_exit(); + if (ret) { + goto error_add_stream_fatal; + } + + health_code_update(); + + /* Get stream file descriptor from socket */ + ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); + if (ret != sizeof(fd)) { + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); + goto end; + } + + health_code_update(); + + /* + * Send status code to session daemon only if the recv works. If the + * above recv() failed, the session daemon is notified through the + * error socket and the teardown is eventually done. + */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto error_add_stream_nosignal; + } + + health_code_update(); + + pthread_mutex_lock(&channel->lock); + new_stream = consumer_stream_create( + channel, + channel->key, + fd, + channel->name, + channel->relayd_id, + channel->session_id, + channel->trace_chunk, + msg.u.stream.cpu, + &alloc_ret, + channel->type, + channel->monitor); + if (new_stream == NULL) { + switch (alloc_ret) { + case -ENOMEM: + case -EINVAL: + default: + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); + break; + } + pthread_mutex_unlock(&channel->lock); + goto error_add_stream_nosignal; + } + + new_stream->wait_fd = fd; + ret = kernctl_get_max_subbuf_size(new_stream->wait_fd, + &new_stream->max_sb_size); + if (ret < 0) { + pthread_mutex_unlock(&channel->lock); + ERR("Failed to get kernel maximal subbuffer size"); + goto error_add_stream_nosignal; + } + + consumer_stream_update_channel_attributes(new_stream, + channel); + + /* + * We've just assigned the channel to the stream so increment the + * refcount right now. We don't need to increment the refcount for + * streams in no monitor because we handle manually the cleanup of + * those. It is very important to make sure there is NO prior + * consumer_del_stream() calls or else the refcount will be unbalanced. + */ + if (channel->monitor) { + uatomic_inc(&new_stream->chan->refcount); + } + + /* + * The buffer flush is done on the session daemon side for the kernel + * so no need for the stream "hangup_flush_done" variable to be + * tracked. This is important for a kernel stream since we don't rely + * on the flush state of the stream to read data. It's not the case for + * user space tracing. + */ + new_stream->hangup_flush_done = 0; + + health_code_update(); + + pthread_mutex_lock(&new_stream->lock); + if (ctx->on_recv_stream) { + ret = ctx->on_recv_stream(new_stream); + if (ret < 0) { + pthread_mutex_unlock(&new_stream->lock); + pthread_mutex_unlock(&channel->lock); + consumer_stream_free(new_stream); + goto error_add_stream_nosignal; + } + } + health_code_update(); + + if (new_stream->metadata_flag) { + channel->metadata_stream = new_stream; + } + + /* Do not monitor this stream. */ + if (!channel->monitor) { + DBG("Kernel consumer add stream %s in no monitor mode with " + "relayd id %" PRIu64, new_stream->name, + new_stream->net_seq_idx); + cds_list_add(&new_stream->send_node, &channel->streams.head); + pthread_mutex_unlock(&new_stream->lock); + pthread_mutex_unlock(&channel->lock); + goto end_add_stream; + } + + /* Send stream to relayd if the stream has an ID. */ + if (new_stream->net_seq_idx != (uint64_t) -1ULL) { + ret = consumer_send_relayd_stream(new_stream, + new_stream->chan->pathname); + if (ret < 0) { + pthread_mutex_unlock(&new_stream->lock); + pthread_mutex_unlock(&channel->lock); + consumer_stream_free(new_stream); + goto error_add_stream_nosignal; + } + + /* + * If adding an extra stream to an already + * existing channel (e.g. cpu hotplug), we need + * to send the "streams_sent" command to relayd. + */ + if (channel->streams_sent_to_relayd) { + ret = consumer_send_relayd_streams_sent( + new_stream->net_seq_idx); + if (ret < 0) { + pthread_mutex_unlock(&new_stream->lock); + pthread_mutex_unlock(&channel->lock); + goto error_add_stream_nosignal; + } + } + } + pthread_mutex_unlock(&new_stream->lock); + pthread_mutex_unlock(&channel->lock); + + /* Get the right pipe where the stream will be sent. */ + if (new_stream->metadata_flag) { + consumer_add_metadata_stream(new_stream); + stream_pipe = ctx->consumer_metadata_pipe; + } else { + consumer_add_data_stream(new_stream); + stream_pipe = ctx->consumer_data_pipe; + } + + /* Visible to other threads */ + new_stream->globally_visible = 1; + + health_code_update(); + + ret = lttng_pipe_write(stream_pipe, &new_stream, sizeof(new_stream)); + if (ret < 0) { + ERR("Consumer write %s stream to pipe %d", + new_stream->metadata_flag ? "metadata" : "data", + lttng_pipe_get_writefd(stream_pipe)); + if (new_stream->metadata_flag) { + consumer_del_stream_for_metadata(new_stream); + } else { + consumer_del_stream_for_data(new_stream); + } + goto error_add_stream_nosignal; + } + + DBG("Kernel consumer ADD_STREAM %s (fd: %d) %s with relayd id %" PRIu64, + new_stream->name, fd, new_stream->chan->pathname, new_stream->relayd_stream_id); +end_add_stream: + break; +error_add_stream_nosignal: + goto end_nosignal; +error_add_stream_fatal: + goto error_fatal; + } + case LTTNG_CONSUMER_STREAMS_SENT: + { + struct lttng_consumer_channel *channel; + + /* + * Get stream's channel reference. Needed when adding the stream to the + * global hash table. + */ + channel = consumer_find_channel(msg.u.sent_streams.channel_key); + if (!channel) { + /* + * We could not find the channel. Can happen if cpu hotplug + * happens while tearing down. + */ + ERR("Unable to find channel key %" PRIu64, + msg.u.sent_streams.channel_key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } + + health_code_update(); + + /* + * Send status code to session daemon. + */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) { + /* Somehow, the session daemon is not responding anymore. */ + goto error_streams_sent_nosignal; + } + + health_code_update(); + + /* + * We should not send this message if we don't monitor the + * streams in this channel. + */ + if (!channel->monitor) { + goto end_error_streams_sent; + } + + health_code_update(); + /* Send stream to relayd if the stream has an ID. */ + if (msg.u.sent_streams.net_seq_idx != (uint64_t) -1ULL) { + ret = consumer_send_relayd_streams_sent( + msg.u.sent_streams.net_seq_idx); + if (ret < 0) { + goto error_streams_sent_nosignal; + } + channel->streams_sent_to_relayd = true; + } +end_error_streams_sent: + break; +error_streams_sent_nosignal: + goto end_nosignal; + } + case LTTNG_CONSUMER_UPDATE_STREAM: + { + rcu_read_unlock(); + return -ENOSYS; + } + case LTTNG_CONSUMER_DESTROY_RELAYD: + { + uint64_t index = msg.u.destroy_relayd.net_seq_idx; + struct consumer_relayd_sock_pair *relayd; + + DBG("Kernel consumer destroying relayd %" PRIu64, index); + + /* Get relayd reference if exists. */ + relayd = consumer_find_relayd(index); + if (relayd == NULL) { + DBG("Unable to find relayd %" PRIu64, index); + ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL; + } + + /* + * Each relayd socket pair has a refcount of stream attached to it + * which tells if the relayd is still active or not depending on the + * refcount value. + * + * This will set the destroy flag of the relayd object and destroy it + * if the refcount reaches zero when called. + * + * The destroy can happen either here or when a stream fd hangs up. + */ + if (relayd) { + consumer_flag_relayd_for_destroy(relayd); + } + + health_code_update(); + + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto error_fatal; + } + + goto end_nosignal; + } + case LTTNG_CONSUMER_DATA_PENDING: + { + int32_t ret; + uint64_t id = msg.u.data_pending.session_id; + + DBG("Kernel consumer data pending command for id %" PRIu64, id); + + ret = consumer_data_pending(id); + + health_code_update(); + + /* Send back returned value to session daemon */ + ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); + if (ret < 0) { + PERROR("send data pending ret code"); + goto error_fatal; + } + + /* + * No need to send back a status message since the data pending + * returned value is the response. + */ + break; + } + case LTTNG_CONSUMER_SNAPSHOT_CHANNEL: + { + struct lttng_consumer_channel *channel; + uint64_t key = msg.u.snapshot_channel.key; + + channel = consumer_find_channel(key); + if (!channel) { + ERR("Channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } else { + pthread_mutex_lock(&channel->lock); + if (msg.u.snapshot_channel.metadata == 1) { + ret = lttng_kconsumer_snapshot_metadata(channel, key, + msg.u.snapshot_channel.pathname, + msg.u.snapshot_channel.relayd_id, ctx); + if (ret < 0) { + ERR("Snapshot metadata failed"); + ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED; + } + } else { + ret = lttng_kconsumer_snapshot_channel(channel, key, + msg.u.snapshot_channel.pathname, + msg.u.snapshot_channel.relayd_id, + msg.u.snapshot_channel.nb_packets_per_stream, + ctx); + if (ret < 0) { + ERR("Snapshot channel failed"); + ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED; + } + } + pthread_mutex_unlock(&channel->lock); + } + health_code_update(); + + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + break; + } + case LTTNG_CONSUMER_DESTROY_CHANNEL: + { + uint64_t key = msg.u.destroy_channel.key; + struct lttng_consumer_channel *channel; + + channel = consumer_find_channel(key); + if (!channel) { + ERR("Kernel consumer destroy channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } + + health_code_update(); + + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_destroy_channel; + } + + health_code_update(); + + /* Stop right now if no channel was found. */ + if (!channel) { + goto end_destroy_channel; + } + + /* + * This command should ONLY be issued for channel with streams set in + * no monitor mode. + */ + assert(!channel->monitor); + + /* + * The refcount should ALWAYS be 0 in the case of a channel in no + * monitor mode. + */ + assert(!uatomic_sub_return(&channel->refcount, 1)); + + consumer_del_channel(channel); +end_destroy_channel: + goto end_nosignal; + } + case LTTNG_CONSUMER_DISCARDED_EVENTS: + { + ssize_t ret; + uint64_t count; + struct lttng_consumer_channel *channel; + uint64_t id = msg.u.discarded_events.session_id; + uint64_t key = msg.u.discarded_events.channel_key; + + DBG("Kernel consumer discarded events command for session id %" + PRIu64 ", channel key %" PRIu64, id, key); + + channel = consumer_find_channel(key); + if (!channel) { + ERR("Kernel consumer discarded events channel %" + PRIu64 " not found", key); + count = 0; + } else { + count = channel->discarded_events; + } + + health_code_update(); + + /* Send back returned value to session daemon */ + ret = lttcomm_send_unix_sock(sock, &count, sizeof(count)); + if (ret < 0) { + PERROR("send discarded events"); + goto error_fatal; + } + + break; + } + case LTTNG_CONSUMER_LOST_PACKETS: + { + ssize_t ret; + uint64_t count; + struct lttng_consumer_channel *channel; + uint64_t id = msg.u.lost_packets.session_id; + uint64_t key = msg.u.lost_packets.channel_key; + + DBG("Kernel consumer lost packets command for session id %" + PRIu64 ", channel key %" PRIu64, id, key); + + channel = consumer_find_channel(key); + if (!channel) { + ERR("Kernel consumer lost packets channel %" + PRIu64 " not found", key); + count = 0; + } else { + count = channel->lost_packets; + } + + health_code_update(); + + /* Send back returned value to session daemon */ + ret = lttcomm_send_unix_sock(sock, &count, sizeof(count)); + if (ret < 0) { + PERROR("send lost packets"); + goto error_fatal; + } + + break; + } + case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE: + { + int channel_monitor_pipe; + + ret_code = LTTCOMM_CONSUMERD_SUCCESS; + /* Successfully received the command's type. */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + goto error_fatal; + } + + ret = lttcomm_recv_fds_unix_sock(sock, &channel_monitor_pipe, + 1); + if (ret != sizeof(channel_monitor_pipe)) { + ERR("Failed to receive channel monitor pipe"); + goto error_fatal; + } + + DBG("Received channel monitor pipe (%d)", channel_monitor_pipe); + ret = consumer_timer_thread_set_channel_monitor_pipe( + channel_monitor_pipe); + if (!ret) { + int flags; + + ret_code = LTTCOMM_CONSUMERD_SUCCESS; + /* Set the pipe as non-blocking. */ + ret = fcntl(channel_monitor_pipe, F_GETFL, 0); + if (ret == -1) { + PERROR("fcntl get flags of the channel monitoring pipe"); + goto error_fatal; + } + flags = ret; + + ret = fcntl(channel_monitor_pipe, F_SETFL, + flags | O_NONBLOCK); + if (ret == -1) { + PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe"); + goto error_fatal; + } + DBG("Channel monitor pipe set as non-blocking"); + } else { + ret_code = LTTCOMM_CONSUMERD_ALREADY_SET; + } + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + goto error_fatal; + } + break; + } + case LTTNG_CONSUMER_ROTATE_CHANNEL: + { + struct lttng_consumer_channel *channel; + uint64_t key = msg.u.rotate_channel.key; + + DBG("Consumer rotate channel %" PRIu64, key); + + channel = consumer_find_channel(key); + if (!channel) { + ERR("Channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } else { + /* + * Sample the rotate position of all the streams in this channel. + */ + ret = lttng_consumer_rotate_channel(channel, key, + msg.u.rotate_channel.relayd_id, + msg.u.rotate_channel.metadata, + ctx); + if (ret < 0) { + ERR("Rotate channel failed"); + ret_code = LTTCOMM_CONSUMERD_ROTATION_FAIL; + } + + health_code_update(); + } + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto error_rotate_channel; + } + if (channel) { + /* Rotate the streams that are ready right now. */ + ret = lttng_consumer_rotate_ready_streams( + channel, key, ctx); + if (ret < 0) { + ERR("Rotate ready streams failed"); + } + } + break; +error_rotate_channel: + goto end_nosignal; + } + case LTTNG_CONSUMER_CLEAR_CHANNEL: + { + struct lttng_consumer_channel *channel; + uint64_t key = msg.u.clear_channel.key; + + channel = consumer_find_channel(key); + if (!channel) { + DBG("Channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } else { + ret = lttng_consumer_clear_channel(channel); + if (ret) { + ERR("Clear channel failed"); + ret_code = ret; + } + + health_code_update(); + } + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + + break; + } + case LTTNG_CONSUMER_INIT: + { + ret_code = lttng_consumer_init_command(ctx, + msg.u.init.sessiond_uuid); + health_code_update(); + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + break; + } + case LTTNG_CONSUMER_CREATE_TRACE_CHUNK: + { + const struct lttng_credentials credentials = { + .uid = msg.u.create_trace_chunk.credentials.value.uid, + .gid = msg.u.create_trace_chunk.credentials.value.gid, + }; + const bool is_local_trace = + !msg.u.create_trace_chunk.relayd_id.is_set; + const uint64_t relayd_id = + msg.u.create_trace_chunk.relayd_id.value; + const char *chunk_override_name = + *msg.u.create_trace_chunk.override_name ? + msg.u.create_trace_chunk.override_name : + NULL; + struct lttng_directory_handle *chunk_directory_handle = NULL; + + /* + * The session daemon will only provide a chunk directory file + * descriptor for local traces. + */ + if (is_local_trace) { + int chunk_dirfd; + + /* Acnowledge the reception of the command. */ + ret = consumer_send_status_msg(sock, + LTTCOMM_CONSUMERD_SUCCESS); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + + ret = lttcomm_recv_fds_unix_sock(sock, &chunk_dirfd, 1); + if (ret != sizeof(chunk_dirfd)) { + ERR("Failed to receive trace chunk directory file descriptor"); + goto error_fatal; + } + + DBG("Received trace chunk directory fd (%d)", + chunk_dirfd); + chunk_directory_handle = lttng_directory_handle_create_from_dirfd( + chunk_dirfd); + if (!chunk_directory_handle) { + ERR("Failed to initialize chunk directory handle from directory file descriptor"); + if (close(chunk_dirfd)) { + PERROR("Failed to close chunk directory file descriptor"); + } + goto error_fatal; + } + } + + ret_code = lttng_consumer_create_trace_chunk( + !is_local_trace ? &relayd_id : NULL, + msg.u.create_trace_chunk.session_id, + msg.u.create_trace_chunk.chunk_id, + (time_t) msg.u.create_trace_chunk + .creation_timestamp, + chunk_override_name, + msg.u.create_trace_chunk.credentials.is_set ? + &credentials : + NULL, + chunk_directory_handle); + lttng_directory_handle_put(chunk_directory_handle); + goto end_msg_sessiond; + } + case LTTNG_CONSUMER_CLOSE_TRACE_CHUNK: + { + enum lttng_trace_chunk_command_type close_command = + msg.u.close_trace_chunk.close_command.value; + const uint64_t relayd_id = + msg.u.close_trace_chunk.relayd_id.value; + struct lttcomm_consumer_close_trace_chunk_reply reply; + char path[LTTNG_PATH_MAX]; + + ret_code = lttng_consumer_close_trace_chunk( + msg.u.close_trace_chunk.relayd_id.is_set ? + &relayd_id : + NULL, + msg.u.close_trace_chunk.session_id, + msg.u.close_trace_chunk.chunk_id, + (time_t) msg.u.close_trace_chunk.close_timestamp, + msg.u.close_trace_chunk.close_command.is_set ? + &close_command : + NULL, path); + reply.ret_code = ret_code; + reply.path_length = strlen(path) + 1; + ret = lttcomm_send_unix_sock(sock, &reply, sizeof(reply)); + if (ret != sizeof(reply)) { + goto error_fatal; + } + ret = lttcomm_send_unix_sock(sock, path, reply.path_length); + if (ret != reply.path_length) { + goto error_fatal; + } + goto end_nosignal; + } + case LTTNG_CONSUMER_TRACE_CHUNK_EXISTS: + { + const uint64_t relayd_id = + msg.u.trace_chunk_exists.relayd_id.value; + + ret_code = lttng_consumer_trace_chunk_exists( + msg.u.trace_chunk_exists.relayd_id.is_set ? + &relayd_id : NULL, + msg.u.trace_chunk_exists.session_id, + msg.u.trace_chunk_exists.chunk_id); + goto end_msg_sessiond; + } + default: + goto end_nosignal; + } + +end_nosignal: + /* + * Return 1 to indicate success since the 0 value can be a socket + * shutdown during the recv() or send() call. + */ + ret = 1; + goto end; +error_fatal: + /* This will issue a consumer stop. */ + ret = -1; + goto end; +end_msg_sessiond: + /* + * The returned value here is not useful since either way we'll return 1 to + * the caller because the session daemon socket management is done + * elsewhere. Returning a negative code or 0 will shutdown the consumer. + */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + goto error_fatal; + } + ret = 1; +end: + health_code_update(); + rcu_read_unlock(); + return ret; +} + +/* + * Sync metadata meaning request them to the session daemon and snapshot to the + * metadata thread can consumer them. + * + * Metadata stream lock MUST be acquired. + * + * Return 0 if new metadatda is available, EAGAIN if the metadata stream + * is empty or a negative value on error. + */ +int lttng_kconsumer_sync_metadata(struct lttng_consumer_stream *metadata) +{ + int ret; + + assert(metadata); + + ret = kernctl_buffer_flush(metadata->wait_fd); + if (ret < 0) { + ERR("Failed to flush kernel stream"); + goto end; + } + + ret = kernctl_snapshot(metadata->wait_fd); + if (ret < 0) { + if (ret != -EAGAIN) { + ERR("Sync metadata, taking kernel snapshot failed."); + goto end; + } + DBG("Sync metadata, no new kernel metadata"); + /* No new metadata, exit. */ + ret = ENODATA; + goto end; + } + +end: + return ret; +} + +static +int extract_common_subbuffer_info(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuf) +{ + int ret; + + ret = kernctl_get_subbuf_size( + stream->wait_fd, &subbuf->info.data.subbuf_size); + if (ret) { + goto end; + } + + ret = kernctl_get_padded_subbuf_size( + stream->wait_fd, &subbuf->info.data.padded_subbuf_size); + if (ret) { + goto end; + } + +end: + return ret; +} + +static +int extract_metadata_subbuffer_info(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuf) +{ + int ret; + + ret = extract_common_subbuffer_info(stream, subbuf); + if (ret) { + goto end; + } + + ret = kernctl_get_metadata_version( + stream->wait_fd, &subbuf->info.metadata.version); + if (ret) { + goto end; + } + +end: + return ret; +} + +static +int extract_data_subbuffer_info(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuf) +{ + int ret; + + ret = extract_common_subbuffer_info(stream, subbuf); + if (ret) { + goto end; + } + + ret = kernctl_get_packet_size( + stream->wait_fd, &subbuf->info.data.packet_size); + if (ret < 0) { + PERROR("Failed to get sub-buffer packet size"); + goto end; + } + + ret = kernctl_get_content_size( + stream->wait_fd, &subbuf->info.data.content_size); + if (ret < 0) { + PERROR("Failed to get sub-buffer content size"); + goto end; + } + + ret = kernctl_get_timestamp_begin( + stream->wait_fd, &subbuf->info.data.timestamp_begin); + if (ret < 0) { + PERROR("Failed to get sub-buffer begin timestamp"); + goto end; + } + + ret = kernctl_get_timestamp_end( + stream->wait_fd, &subbuf->info.data.timestamp_end); + if (ret < 0) { + PERROR("Failed to get sub-buffer end timestamp"); + goto end; + } + + ret = kernctl_get_events_discarded( + stream->wait_fd, &subbuf->info.data.events_discarded); + if (ret) { + PERROR("Failed to get sub-buffer events discarded count"); + goto end; + } + + ret = kernctl_get_sequence_number(stream->wait_fd, + &subbuf->info.data.sequence_number.value); + if (ret) { + /* May not be supported by older LTTng-modules. */ + if (ret != -ENOTTY) { + PERROR("Failed to get sub-buffer sequence number"); + goto end; + } + } else { + subbuf->info.data.sequence_number.is_set = true; + } + + ret = kernctl_get_stream_id( + stream->wait_fd, &subbuf->info.data.stream_id); + if (ret < 0) { + PERROR("Failed to get stream id"); + goto end; + } + + ret = kernctl_get_instance_id(stream->wait_fd, + &subbuf->info.data.stream_instance_id.value); + if (ret) { + /* May not be supported by older LTTng-modules. */ + if (ret != -ENOTTY) { + PERROR("Failed to get stream instance id"); + goto end; + } + } else { + subbuf->info.data.stream_instance_id.is_set = true; + } +end: + return ret; +} + +static +int get_subbuffer_common(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + int ret; + + ret = kernctl_get_next_subbuf(stream->wait_fd); + if (ret) { + goto end; + } + + ret = stream->read_subbuffer_ops.extract_subbuffer_info( + stream, subbuffer); +end: + return ret; +} + +static +int get_next_subbuffer_splice(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + int ret; + + ret = get_subbuffer_common(stream, subbuffer); + if (ret) { + goto end; + } + + subbuffer->buffer.fd = stream->wait_fd; +end: + return ret; +} + +static +int get_next_subbuffer_mmap(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + int ret; + const char *addr; + + ret = get_subbuffer_common(stream, subbuffer); + if (ret) { + goto end; + } + + ret = get_current_subbuf_addr(stream, &addr); + if (ret) { + goto end; + } + + subbuffer->buffer.buffer = lttng_buffer_view_init( + addr, 0, subbuffer->info.data.padded_subbuf_size); +end: + return ret; +} + +static +int put_next_subbuffer(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + const int ret = kernctl_put_next_subbuf(stream->wait_fd); + + if (ret) { + if (ret == -EFAULT) { + PERROR("Error in unreserving sub buffer"); + } else if (ret == -EIO) { + /* Should never happen with newer LTTng versions */ + PERROR("Reader has been pushed by the writer, last sub-buffer corrupted"); + } + } + + return ret; +} + +static void lttng_kconsumer_set_stream_ops( + struct lttng_consumer_stream *stream) +{ + if (stream->chan->output == CONSUMER_CHANNEL_MMAP) { + stream->read_subbuffer_ops.get_next_subbuffer = + get_next_subbuffer_mmap; + } else { + stream->read_subbuffer_ops.get_next_subbuffer = + get_next_subbuffer_splice; + } + + if (stream->metadata_flag) { + stream->read_subbuffer_ops.extract_subbuffer_info = + extract_metadata_subbuffer_info; + } else { + stream->read_subbuffer_ops.extract_subbuffer_info = + extract_data_subbuffer_info; + if (stream->chan->is_live) { + stream->read_subbuffer_ops.send_live_beacon = + consumer_flush_kernel_index; + } + } + + stream->read_subbuffer_ops.put_next_subbuffer = put_next_subbuffer; +} + +int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) +{ + int ret; + + assert(stream); + + /* + * Don't create anything if this is set for streaming or if there is + * no current trace chunk on the parent channel. + */ + if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor && + stream->chan->trace_chunk) { + ret = consumer_stream_create_output_files(stream, true); + if (ret) { + goto error; + } + } + + if (stream->output == LTTNG_EVENT_MMAP) { + /* get the len of the mmap region */ + unsigned long mmap_len; + + ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); + if (ret != 0) { + PERROR("kernctl_get_mmap_len"); + goto error_close_fd; + } + stream->mmap_len = (size_t) mmap_len; + + stream->mmap_base = mmap(NULL, stream->mmap_len, PROT_READ, + MAP_PRIVATE, stream->wait_fd, 0); + if (stream->mmap_base == MAP_FAILED) { + PERROR("Error mmaping"); + ret = -1; + goto error_close_fd; + } + } + + lttng_kconsumer_set_stream_ops(stream); + + /* we return 0 to let the library handle the FD internally */ + return 0; + +error_close_fd: + if (stream->out_fd >= 0) { + int err; + + err = close(stream->out_fd); + assert(!err); + stream->out_fd = -1; + } +error: + return ret; +} + +/* + * Check if data is still being extracted from the buffers for a specific + * stream. Consumer data lock MUST be acquired before calling this function + * and the stream lock. + * + * Return 1 if the traced data are still getting read else 0 meaning that the + * data is available for trace viewer reading. + */ +int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream) +{ + int ret; + + assert(stream); + + if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) { + ret = 0; + goto end; + } + + ret = kernctl_get_next_subbuf(stream->wait_fd); + if (ret == 0) { + /* There is still data so let's put back this subbuffer. */ + ret = kernctl_put_subbuf(stream->wait_fd); + assert(ret == 0); + ret = 1; /* Data is pending */ + goto end; + } + + /* Data is NOT pending and ready to be read. */ + ret = 0; + +end: + return ret; +}