Consumer: implement LTTNG_CONSUMER_CLEAR_CHANNEL

[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 2c30bed29c1492bb005dcc759ec91ce02acd88d7..7039b3b80cfc833ff830eb84c8ef70cc03b5c0bb 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -60,7 +60,11 @@ int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream)
        int infd = stream->wait_fd;
 
        ret = kernctl_snapshot(infd);
-       if (ret != 0) {
+       /*
+        * -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.");
        }
 
@@ -187,14 +191,6 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        DBG("Kernel consumer snapshot stream %s/%s (%" PRIu64 ")",
                                        path, stream->name, stream->key);
                }
-               if (relayd_id != -1ULL) {
-                       ret = consumer_send_relayd_streams_sent(relayd_id);
-                       if (ret < 0) {
-                               ERR("sending streams sent to relayd");
-                               goto end_unlock;
-                       }
-                       channel->streams_sent_to_relayd = true;
-               }
 
                ret = kernctl_buffer_flush_empty(stream->wait_fd);
                if (ret < 0) {
@@ -340,7 +336,7 @@ end:
  *
  * Returns 0 on success, < 0 on error
  */
-int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
+static int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
                uint64_t relayd_id, struct lttng_consumer_local_data *ctx)
 {
        int ret, use_relayd = 0;
@@ -359,11 +355,12 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
        if (!metadata_channel) {
                ERR("Kernel snapshot metadata not found for key %" PRIu64, key);
                ret = -1;
-               goto error;
+               goto error_no_channel;
        }
 
        metadata_stream = metadata_channel->metadata_stream;
        assert(metadata_stream);
+       pthread_mutex_lock(&metadata_stream->lock);
 
        /* Flag once that we have a valid relayd for the stream. */
        if (relayd_id != (uint64_t) -1ULL) {
@@ -373,7 +370,7 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
        if (use_relayd) {
                ret = consumer_send_relayd_stream(metadata_stream, path);
                if (ret < 0) {
-                       goto error;
+                       goto error_snapshot;
                }
        } else {
                ret = utils_create_stream_file(path, metadata_stream->name,
@@ -381,7 +378,7 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
                                metadata_stream->tracefile_count_current,
                                metadata_stream->uid, metadata_stream->gid, NULL);
                if (ret < 0) {
-                       goto error;
+                       goto error_snapshot;
                }
                metadata_stream->out_fd = ret;
        }
@@ -394,7 +391,8 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
                        if (ret_read != -EAGAIN) {
                                ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
                                                ret_read);
-                               goto error;
+                               ret = ret_read;
+                               goto error_snapshot;
                        }
                        /* ret_read is negative at this point so we will exit the loop. */
                        continue;
@@ -419,11 +417,12 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
        }
 
        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;
-error:
+error_no_channel:
        rcu_read_unlock();
        return ret;
 }
@@ -465,10 +464,10 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
        case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
        {
                /* Session daemon status message are handled in the following call. */
-               ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
+               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.relayd_session_id);
                goto end_nosignal;
        }
        case LTTNG_CONSUMER_ADD_CHANNEL:
@@ -983,7 +982,8 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
        }
        case LTTNG_CONSUMER_DISCARDED_EVENTS:
        {
-               uint64_t ret;
+               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;
@@ -995,15 +995,15 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                if (!channel) {
                        ERR("Kernel consumer discarded events channel %"
                                        PRIu64 " not found", key);
-                       ret = 0;
+                       count = 0;
                } else {
-                       ret = channel->discarded_events;
+                       count = channel->discarded_events;
                }
 
                health_code_update();
 
                /* Send back returned value to session daemon */
-               ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+               ret = lttcomm_send_unix_sock(sock, &count, sizeof(count));
                if (ret < 0) {
                        PERROR("send discarded events");
                        goto error_fatal;
@@ -1013,7 +1013,8 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
        }
        case LTTNG_CONSUMER_LOST_PACKETS:
        {
-               uint64_t ret;
+               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;
@@ -1025,15 +1026,15 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                if (!channel) {
                        ERR("Kernel consumer lost packets channel %"
                                        PRIu64 " not found", key);
-                       ret = 0;
+                       count = 0;
                } else {
-                       ret = channel->lost_packets;
+                       count = channel->lost_packets;
                }
 
                health_code_update();
 
                /* Send back returned value to session daemon */
-               ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+               ret = lttcomm_send_unix_sock(sock, &count, sizeof(count));
                if (ret < 0) {
                        PERROR("send lost packets");
                        goto error_fatal;
@@ -1090,6 +1091,31 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                }
                break;
        }
+       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;
+       }
        default:
                goto end_nosignal;
        }