X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=6b3984eb6902cf7286767920bb315dfa14126590;hb=18acc0a479471e15fb7b7fc3ca5f38e7ce8f72d3;hp=083c8c0c7143b5c1048221f3868916885e3d90bf;hpb=afbf29db446cbce8b0c72ca3ffceb552d153fcb1;p=lttng-tools.git diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c index 083c8c0c7..6b3984eb6 100644 --- a/src/common/kernel-consumer/kernel-consumer.c +++ b/src/common/kernel-consumer/kernel-consumer.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2011 Julien Desfossez + * Copyright (C) 2011 EfficiOS Inc. * Copyright (C) 2011 Mathieu Desnoyers * Copyright (C) 2017 Jérémie Galarneau * @@ -139,7 +139,7 @@ error: /* * 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. + * channel. * * Returns 0 on success, < 0 on error */ @@ -154,6 +154,9 @@ static int lttng_kconsumer_snapshot_channel( DBG("Kernel consumer snapshot channel %" PRIu64, key); + /* Prevent channel modifications while we perform the snapshot.*/ + pthread_mutex_lock(&channel->lock); + rcu_read_lock(); /* Splice is not supported yet for channel snapshot. */ @@ -347,13 +350,14 @@ end_unlock: pthread_mutex_unlock(&stream->lock); end: rcu_read_unlock(); + pthread_mutex_unlock(&channel->lock); return ret; } /* * 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. + * metadata_channel. * * Returns 0 on success, < 0 on error */ @@ -376,7 +380,7 @@ static int lttng_kconsumer_snapshot_metadata( metadata_stream = metadata_channel->metadata_stream; assert(metadata_stream); - pthread_mutex_lock(&metadata_stream->lock); + metadata_stream->read_subbuffer_ops.lock(metadata_stream); assert(metadata_channel->trace_chunk); assert(metadata_stream->trace_chunk); @@ -403,16 +407,12 @@ static int lttng_kconsumer_snapshot_metadata( 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; - } - /* ret_read is negative at this point so we will exit the loop. */ - continue; + ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)", + ret_read); + ret = ret_read; + goto error_snapshot; } - } while (ret_read >= 0); + } while (ret_read > 0); if (use_relayd) { close_relayd_stream(metadata_stream); @@ -435,8 +435,7 @@ static int lttng_kconsumer_snapshot_metadata( ret = 0; error_snapshot: - pthread_mutex_unlock(&metadata_stream->lock); - cds_list_del(&metadata_stream->send_node); + metadata_stream->read_subbuffer_ops.unlock(metadata_stream); consumer_stream_destroy(metadata_stream, NULL); metadata_channel->metadata_stream = NULL; rcu_read_unlock(); @@ -484,11 +483,17 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, switch (msg.cmd_type) { case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: { + uint32_t major = msg.u.relayd_sock.major; + uint32_t minor = msg.u.relayd_sock.minor; + enum lttcomm_sock_proto protocol = (enum lttcomm_sock_proto) + msg.u.relayd_sock.relayd_socket_protocol; + /* 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); + msg.u.relayd_sock.type, ctx, sock, + consumer_sockpoll, msg.u.relayd_sock.session_id, + msg.u.relayd_sock.relayd_session_id, major, + minor, protocol); goto end_nosignal; } case LTTNG_CONSUMER_ADD_CHANNEL: @@ -965,7 +970,6 @@ error_streams_sent_nosignal: 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) { int ret_snapshot; @@ -993,7 +997,6 @@ error_streams_sent_nosignal: ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED; } } - pthread_mutex_unlock(&channel->lock); } health_code_update(); @@ -1587,68 +1590,94 @@ end: } static -int get_subbuffer_common(struct lttng_consumer_stream *stream, +enum get_next_subbuffer_status get_subbuffer_common( + struct lttng_consumer_stream *stream, struct stream_subbuffer *subbuffer) { int ret; + enum get_next_subbuffer_status status; ret = kernctl_get_next_subbuf(stream->wait_fd); - if (ret) { + switch (ret) { + case 0: + status = GET_NEXT_SUBBUFFER_STATUS_OK; + break; + case -ENODATA: + case -EAGAIN: + /* + * The caller only expects -ENODATA when there is no data to + * read, but the kernel tracer returns -EAGAIN when there is + * currently no data for a non-finalized stream, and -ENODATA + * when there is no data for a finalized stream. Those can be + * combined into a -ENODATA return value. + */ + status = GET_NEXT_SUBBUFFER_STATUS_NO_DATA; + goto end; + default: + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; goto end; } ret = stream->read_subbuffer_ops.extract_subbuffer_info( - stream, subbuffer); + stream, subbuffer); + if (ret) { + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + } end: - return ret; + return status; } static -int get_next_subbuffer_splice(struct lttng_consumer_stream *stream, +enum get_next_subbuffer_status get_next_subbuffer_splice( + struct lttng_consumer_stream *stream, struct stream_subbuffer *subbuffer) { - int ret; + const enum get_next_subbuffer_status status = + get_subbuffer_common(stream, subbuffer); - ret = get_subbuffer_common(stream, subbuffer); - if (ret) { + if (status != GET_NEXT_SUBBUFFER_STATUS_OK) { goto end; } subbuffer->buffer.fd = stream->wait_fd; end: - return ret; + return status; } static -int get_next_subbuffer_mmap(struct lttng_consumer_stream *stream, +enum get_next_subbuffer_status get_next_subbuffer_mmap( + struct lttng_consumer_stream *stream, struct stream_subbuffer *subbuffer) { int ret; + enum get_next_subbuffer_status status; const char *addr; - ret = get_subbuffer_common(stream, subbuffer); - if (ret) { + status = get_subbuffer_common(stream, subbuffer); + if (status != GET_NEXT_SUBBUFFER_STATUS_OK) { goto end; } ret = get_current_subbuf_addr(stream, &addr); if (ret) { + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; goto end; } subbuffer->buffer.buffer = lttng_buffer_view_init( addr, 0, subbuffer->info.data.padded_subbuf_size); end: - return ret; + return status; } static -int get_next_subbuffer_metadata_check(struct lttng_consumer_stream *stream, +enum get_next_subbuffer_status get_next_subbuffer_metadata_check(struct lttng_consumer_stream *stream, struct stream_subbuffer *subbuffer) { int ret; const char *addr; bool coherent; + enum get_next_subbuffer_status status; ret = kernctl_get_next_subbuf_metadata_check(stream->wait_fd, &coherent); @@ -1675,7 +1704,33 @@ int get_next_subbuffer_metadata_check(struct lttng_consumer_stream *stream, subbuffer->info.metadata.padded_subbuf_size, coherent ? "true" : "false"); end: - return ret; + /* + * The caller only expects -ENODATA when there is no data to read, but + * the kernel tracer returns -EAGAIN when there is currently no data + * for a non-finalized stream, and -ENODATA when there is no data for a + * finalized stream. Those can be combined into a -ENODATA return value. + */ + switch (ret) { + case 0: + status = GET_NEXT_SUBBUFFER_STATUS_OK; + break; + case -ENODATA: + case -EAGAIN: + /* + * The caller only expects -ENODATA when there is no data to + * read, but the kernel tracer returns -EAGAIN when there is + * currently no data for a non-finalized stream, and -ENODATA + * when there is no data for a finalized stream. Those can be + * combined into a -ENODATA return value. + */ + status = GET_NEXT_SUBBUFFER_STATUS_NO_DATA; + break; + default: + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + break; + } + + return status; } static @@ -1699,8 +1754,23 @@ int put_next_subbuffer(struct lttng_consumer_stream *stream, static bool is_get_next_check_metadata_available(int tracer_fd) { - return kernctl_get_next_subbuf_metadata_check(tracer_fd, NULL) != - -ENOTTY; + const int ret = kernctl_get_next_subbuf_metadata_check(tracer_fd, NULL); + const bool available = ret != -ENOTTY; + + if (ret == 0) { + /* get succeeded, make sure to put the subbuffer. */ + kernctl_put_subbuf(tracer_fd); + } + + return available; +} + +static +int signal_metadata(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx) +{ + ASSERT_LOCKED(stream->metadata_rdv_lock); + return pthread_cond_broadcast(&stream->metadata_rdv) ? -errno : 0; } static @@ -1733,6 +1803,8 @@ int lttng_kconsumer_set_stream_ops( metadata_bucket_destroy(stream->metadata_bucket); stream->metadata_bucket = NULL; } + + stream->read_subbuffer_ops.on_sleep = signal_metadata; } if (!stream->read_subbuffer_ops.get_next_subbuffer) {