Fix: wrong error code returned by kernel_snapshot_record()

[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index aa51649783f64c0e324c0090c42033cdbbb41f7a..07525480e8d690ac393e4ebb672e5f9c866d9bf7 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -36,6 +36,8 @@
 
 /*
  * Add context on a kernel channel.
+ *
+ * Assumes the ownership of ctx.
  */
 int kernel_add_channel_context(struct ltt_kernel_channel *chan,
                struct ltt_kernel_context *ctx)
@@ -66,9 +68,12 @@ int kernel_add_channel_context(struct ltt_kernel_channel *chan,
 
 end:
        cds_list_add_tail(&ctx->list, &chan->ctx_list);
-       return 0;
-
+       ctx->in_list = true;
+       ctx = NULL;
 error:
+       if (ctx) {
+               trace_kernel_destroy_context(ctx);
+       }
        return ret;
 }
 
@@ -644,17 +649,22 @@ error:
  * Open stream of channel, register it to the kernel tracer and add it
  * to the stream list of the channel.
  *
+ * Note: given that the streams may appear in random order wrt CPU
+ * number (e.g. cpu hotplug), the index value of the stream number in
+ * the stream name is not necessarily linked to the CPU number.
+ *
  * Return the number of created stream. Else, a negative value.
  */
 int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
 {
-       int ret, count = 0;
+       int ret;
        struct ltt_kernel_stream *lks;
 
        assert(channel);
 
        while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
-               lks = trace_kernel_create_stream(channel->channel->name, count);
+               lks = trace_kernel_create_stream(channel->channel->name,
+                               channel->stream_count);
                if (lks == NULL) {
                        ret = close(ret);
                        if (ret) {
@@ -673,13 +683,10 @@ int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
                lks->tracefile_size = channel->channel->attr.tracefile_size;
                lks->tracefile_count = channel->channel->attr.tracefile_count;
 
-               /* Add stream to channe stream list */
+               /* Add stream to channel stream list */
                cds_list_add(&lks->list, &channel->stream_list.head);
                channel->stream_count++;
 
-               /* Increment counter which represent CPU number. */
-               count++;
-
                DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd,
                                lks->state);
        }
@@ -1015,18 +1022,16 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
                /* Put back the saved consumer output into the session. */
                ksess->consumer = saved_output;
                if (ret < 0) {
-                       ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+                       ret = LTTNG_ERR_KERN_META_FAIL;
                        goto error_consumer;
                }
 
                /* For each channel, ask the consumer to snapshot it. */
                cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
-                       pthread_mutex_lock(socket->lock);
                        ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
                                        ksess->uid, ksess->gid,
                                        DEFAULT_KERNEL_TRACE_DIR, wait,
                                        nb_packets_per_stream);
-                       pthread_mutex_unlock(socket->lock);
                        if (ret < 0) {
                                ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
                                (void) kernel_consumer_destroy_metadata(socket,
@@ -1036,11 +1041,9 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
                }
 
                /* Snapshot metadata, */
-               pthread_mutex_lock(socket->lock);
                ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
                                1, ksess->uid, ksess->gid,
                                DEFAULT_KERNEL_TRACE_DIR, wait, 0);
-               pthread_mutex_unlock(socket->lock);
                if (ret < 0) {
                        ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
                        goto error_consumer;