Fix: add missing metadata socket lock
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
index 3133835be78091700eaa64e16e114626ca8327f2..986826fca267c455ba9825ea288edbff2e1ca8f4 100644 (file)
@@ -230,8 +230,18 @@ static int create_ust_streams(struct lttng_consumer_channel *channel,
         */
        while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
                int wait_fd;
+               int ust_metadata_pipe[2];
 
-               wait_fd = ustctl_stream_get_wait_fd(ustream);
+               if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
+                       ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
+                       if (ret < 0) {
+                               ERR("Create ust metadata poll pipe");
+                               goto error;
+                       }
+                       wait_fd = ust_metadata_pipe[0];
+               } else {
+                       wait_fd = ustctl_stream_get_wait_fd(ustream);
+               }
 
                /* Allocate consumer stream object. */
                stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
@@ -285,6 +295,8 @@ static int create_ust_streams(struct lttng_consumer_channel *channel,
                /* Keep stream reference when creating metadata. */
                if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
                        channel->metadata_stream = stream;
+                       stream->ust_metadata_poll_pipe[0] = ust_metadata_pipe[0];
+                       stream->ust_metadata_poll_pipe[1] = ust_metadata_pipe[1];
                }
        }
 
@@ -343,7 +355,7 @@ static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
        assert(stream);
        assert(sock >= 0);
 
-       DBG2("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
+       DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
 
        /* Send stream to session daemon. */
        ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
@@ -373,18 +385,20 @@ static int send_sessiond_channel(int sock,
 
        DBG("UST consumer sending channel %s to sessiond", channel->name);
 
-       cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
-               /* Try to send the stream to the relayd if one is available. */
-               ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
-               if (ret < 0) {
-                       /*
-                        * Flag that the relayd was the problem here probably due to a
-                        * communicaton error on the socket.
-                        */
-                       if (relayd_error) {
-                               *relayd_error = 1;
+       if (channel->relayd_id != (uint64_t) -1ULL) {
+               cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+                       /* Try to send the stream to the relayd if one is available. */
+                       ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
+                       if (ret < 0) {
+                               /*
+                                * Flag that the relayd was the problem here probably due to a
+                                * communicaton error on the socket.
+                                */
+                               if (relayd_error) {
+                                       *relayd_error = 1;
+                               }
+                               ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
                        }
-                       ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
                }
        }
 
@@ -636,6 +650,7 @@ static int close_metadata(uint64_t chan_key)
        }
 
        pthread_mutex_lock(&consumer_data.lock);
+       pthread_mutex_lock(&channel->lock);
 
        if (cds_lfht_is_node_deleted(&channel->node.node)) {
                goto error_unlock;
@@ -653,9 +668,17 @@ static int close_metadata(uint64_t chan_key)
                        ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
                        goto error_unlock;
                }
+               if (channel->monitor) {
+                       /* close the read-side in consumer_del_metadata_stream */
+                       ret = close(channel->metadata_stream->ust_metadata_poll_pipe[1]);
+                       if (ret < 0) {
+                               PERROR("Close UST metadata write-side poll pipe");
+                       }
+               }
        }
 
 error_unlock:
+       pthread_mutex_unlock(&channel->lock);
        pthread_mutex_unlock(&consumer_data.lock);
 error:
        return ret;
@@ -701,11 +724,13 @@ static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
        }
 
        /* Send metadata stream to relayd if needed. */
-       ret = consumer_send_relayd_stream(metadata->metadata_stream,
-                       metadata->pathname);
-       if (ret < 0) {
-               ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
-               goto error;
+       if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
+               ret = consumer_send_relayd_stream(metadata->metadata_stream,
+                               metadata->pathname);
+               if (ret < 0) {
+                       ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
+                       goto error;
+               }
        }
 
        ret = send_streams_to_thread(metadata, ctx);
@@ -746,8 +771,6 @@ static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
                struct lttng_consumer_local_data *ctx)
 {
        int ret = 0;
-       ssize_t write_len;
-       uint64_t total_len = 0;
        struct lttng_consumer_channel *metadata_channel;
        struct lttng_consumer_stream *metadata_stream;
 
@@ -807,30 +830,13 @@ static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
        }
 
        pthread_mutex_lock(&metadata_channel->metadata_cache->lock);
-       while (total_len < metadata_channel->metadata_cache->total_bytes_written) {
-               /*
-                * Write at most one packet of metadata into the channel
-                * to avoid blocking here.
-                */
-               write_len = ustctl_write_one_packet_to_channel(metadata_channel->uchan,
-                               metadata_channel->metadata_cache->data,
-                               metadata_channel->metadata_cache->total_bytes_written);
-               if (write_len < 0) {
-                       ERR("UST consumer snapshot writing metadata packet");
-                       ret = -1;
-                       goto error_unlock;
-               }
-               total_len += write_len;
 
-               DBG("Written %" PRIu64 " bytes to metadata (left: %" PRIu64 ")",
-                               write_len,
-                               metadata_channel->metadata_cache->total_bytes_written - write_len);
-               ustctl_flush_buffer(metadata_stream->ustream, 1);
+       do {
                ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
                if (ret < 0) {
                        goto error_unlock;
                }
-       }
+       } while (ret > 0);
 
 error_unlock:
        pthread_mutex_unlock(&metadata_channel->metadata_cache->lock);
@@ -855,7 +861,7 @@ error:
  * Returns 0 on success, < 0 on error
  */
 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
-               struct lttng_consumer_local_data *ctx)
+               uint64_t max_stream_size, struct lttng_consumer_local_data *ctx)
 {
        int ret;
        unsigned use_relayd = 0;
@@ -926,6 +932,15 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
                        goto error_unlock;
                }
 
+               /*
+                * The original value is sent back if max stream size is larger than
+                * the possible size of the snapshot. Also, we asume that the session
+                * daemon should never send a maximum stream size that is lower than
+                * subbuffer size.
+                */
+               consumed_pos = consumer_get_consumed_maxsize(consumed_pos,
+                               produced_pos, max_stream_size);
+
                while (consumed_pos < produced_pos) {
                        ssize_t read_len;
                        unsigned long len, padded_len;
@@ -1034,7 +1049,7 @@ int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
         * and ultimately try to get rid of this global consumer data lock.
         */
        pthread_mutex_lock(&consumer_data.lock);
-
+       pthread_mutex_lock(&channel->lock);
        pthread_mutex_lock(&channel->metadata_cache->lock);
        ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
        if (ret < 0) {
@@ -1046,10 +1061,12 @@ int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
                 * waiting for the metadata cache to be flushed.
                 */
                pthread_mutex_unlock(&channel->metadata_cache->lock);
+               pthread_mutex_unlock(&channel->lock);
                pthread_mutex_unlock(&consumer_data.lock);
                goto end_free;
        }
        pthread_mutex_unlock(&channel->metadata_cache->lock);
+       pthread_mutex_unlock(&channel->lock);
        pthread_mutex_unlock(&consumer_data.lock);
 
        while (consumer_metadata_cache_flushed(channel, offset + len)) {
@@ -1421,6 +1438,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                        ret = snapshot_channel(msg.u.snapshot_channel.key,
                                        msg.u.snapshot_channel.pathname,
                                        msg.u.snapshot_channel.relayd_id,
+                                       msg.u.snapshot_channel.max_stream_size,
                                        ctx);
                        if (ret < 0) {
                                ERR("Snapshot channel failed");
@@ -1598,28 +1616,57 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
        assert(stream->ustream);
        assert(ctx);
 
-       DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
+       DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
                        stream->name);
 
        /* Ease our life for what's next. */
        ustream = stream->ustream;
 
        /* We can consume the 1 byte written into the wait_fd by UST */
-       if (!stream->hangup_flush_done) {
+       if (stream->monitor && !stream->hangup_flush_done) {
                ssize_t readlen;
 
                do {
                        readlen = read(stream->wait_fd, &dummy, 1);
                } while (readlen == -1 && errno == EINTR);
-               if (readlen == -1) {
+               if (readlen == -1 && errno != EAGAIN && errno != EWOULDBLOCK) {
                        ret = readlen;
                        goto end;
                }
        }
 
+retry:
        /* Get the next subbuffer */
        err = ustctl_get_next_subbuf(ustream);
        if (err != 0) {
+               /*
+                * Populate metadata info if the existing info has
+                * already been read.
+                */
+               if (stream->metadata_flag) {
+                       ssize_t write_len;
+
+                       if (stream->chan->metadata_cache->contiguous
+                                       == stream->ust_metadata_pushed) {
+                               ret = 0;
+                               goto end;
+                       }
+
+                       write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
+                                       &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
+                                       stream->chan->metadata_cache->contiguous
+                                               - stream->ust_metadata_pushed);
+                       assert(write_len != 0);
+                       if (write_len < 0) {
+                               ERR("Writing one metadata packet");
+                               ret = -1;
+                               goto end;
+                       }
+                       stream->ust_metadata_pushed += write_len;
+                       ustctl_flush_buffer(stream->ustream, 1);
+                       goto retry;
+               }
+
                ret = err;      /* ustctl_get_next_subbuf returns negative, caller expect positive. */
                /*
                 * This is a debug message even for single-threaded consumer,
@@ -1716,15 +1763,44 @@ int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
 
        DBG("UST consumer checking data pending");
 
-       ret = ustctl_get_next_subbuf(stream->ustream);
-       if (ret == 0) {
-               /* There is still data so let's put back this subbuffer. */
-               ret = ustctl_put_subbuf(stream->ustream);
-               assert(ret == 0);
-               ret = 1;  /* Data is pending */
+       if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
+               ret = 0;
                goto end;
        }
 
+       if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
+               /*
+                * We can simply check whether all contiguously available data
+                * has been pushed to the ring buffer, since the push operation
+                * is performed within get_next_subbuf(), and because both
+                * get_next_subbuf() and put_next_subbuf() are issued atomically
+                * thanks to the stream lock within
+                * lttng_ustconsumer_read_subbuffer(). This basically means that
+                * whetnever ust_metadata_pushed is incremented, the associated
+                * metadata has been consumed from the metadata stream.
+                */
+               DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
+                       stream->chan->metadata_cache->contiguous,
+                       stream->ust_metadata_pushed);
+               if (stream->chan->metadata_cache->contiguous
+                               != stream->ust_metadata_pushed) {
+                       ret = 1;        /* Data is pending */
+                       goto end;
+               }
+       } else {
+               ret = ustctl_get_next_subbuf(stream->ustream);
+               if (ret == 0) {
+                       /*
+                        * There is still data so let's put back this
+                        * subbuffer.
+                        */
+                       ret = ustctl_put_subbuf(stream->ustream);
+                       assert(ret == 0);
+                       ret = 1;        /* Data is pending */
+                       goto end;
+               }
+       }
+
        /* Data is NOT pending so ready to be read. */
        ret = 0;
 
@@ -1814,6 +1890,7 @@ int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
                        channel->session_id,
                        channel->session_id_per_pid);
 
+       pthread_mutex_lock(&ctx->metadata_socket_lock);
        ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
                        sizeof(request));
        if (ret < 0) {
@@ -1879,5 +1956,6 @@ int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
        ret = 0;
 
 end:
+       pthread_mutex_unlock(&ctx->metadata_socket_lock);
        return ret;
 }
This page took 0.028049 seconds and 4 git commands to generate.