Fix: lttng-sessiond: cpu hotplug: send channel to consumer only once

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

diff --git a/src/bin/lttng-sessiond/kernel-consumer.c b/src/bin/lttng-sessiond/kernel-consumer.c
index 89c8760d2673bbda82f20ef2b308b95f7ec3d17f..3649374efb0ae38cf6f1685df734abe7f6d28d88 100644 (file)
--- a/src/bin/lttng-sessiond/kernel-consumer.c
+++ b/src/bin/lttng-sessiond/kernel-consumer.c
@@ -15,15 +15,15 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
 #include <common/common.h>
 #include <common/defaults.h>
+#include <common/compat/string.h>
 
 #include "consumer.h"
 #include "health-sessiond.h"
@@ -47,12 +47,16 @@ static char *create_channel_path(struct consumer_output *consumer,
                        PERROR("snprintf kernel channel path");
                        goto error;
                }
-               pathname = strndup(tmp_path, sizeof(tmp_path));
+               pathname = lttng_strndup(tmp_path, sizeof(tmp_path));
+               if (!pathname) {
+                       PERROR("lttng_strndup");
+                       goto error;
+               }
 
                /* Create directory */
                ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG, uid, gid);
                if (ret < 0) {
-                       if (ret != -EEXIST) {
+                       if (errno != EEXIST) {
                                ERR("Trace directory creation error");
                                goto error;
                        }
@@ -64,7 +68,11 @@ static char *create_channel_path(struct consumer_output *consumer,
                        PERROR("snprintf kernel metadata path");
                        goto error;
                }
-               pathname = strndup(tmp_path, sizeof(tmp_path));
+               pathname = lttng_strndup(tmp_path, sizeof(tmp_path));
+               if (!pathname) {
+                       PERROR("lttng_strndup");
+                       goto error;
+               }
                DBG3("Kernel network consumer subdir path: %s", pathname);
        }
 
@@ -99,14 +107,14 @@ int kernel_consumer_add_channel(struct consumer_socket *sock,
 
        if (monitor) {
                pathname = create_channel_path(consumer, session->uid, session->gid);
-               if (!pathname) {
-                       ret = -1;
-                       goto error;
-               }
        } else {
                /* Empty path. */
                pathname = strdup("");
        }
+       if (!pathname) {
+               ret = -1;
+               goto error;
+       }
 
        /* Prep channel message structure */
        consumer_init_channel_comm_msg(&lkm,
@@ -163,14 +171,14 @@ int kernel_consumer_add_metadata(struct consumer_socket *sock,
 
        if (monitor) {
                pathname = create_channel_path(consumer, session->uid, session->gid);
-               if (!pathname) {
-                       ret = -1;
-                       goto error;
-               }
        } else {
                /* Empty path. */
                pathname = strdup("");
        }
+       if (!pathname) {
+               ret = -1;
+               goto error;
+       }
 
        /* Prep channel message structure */
        consumer_init_channel_comm_msg(&lkm,
@@ -305,7 +313,7 @@ int kernel_consumer_send_channel_stream(struct consumer_socket *sock,
                struct ltt_kernel_channel *channel, struct ltt_kernel_session *session,
                unsigned int monitor)
 {
-       int ret;
+       int ret = LTTNG_OK;
        struct ltt_kernel_stream *stream;
 
        /* Safety net */
@@ -323,14 +331,17 @@ int kernel_consumer_send_channel_stream(struct consumer_socket *sock,
        DBG("Sending streams of channel %s to kernel consumer",
                        channel->channel->name);
 
-       ret = kernel_consumer_add_channel(sock, channel, session, monitor);
-       if (ret < 0) {
-               goto error;
+       if (!channel->sent_to_consumer) {
+               ret = kernel_consumer_add_channel(sock, channel, session, monitor);
+               if (ret < 0) {
+                       goto error;
+               }
+               channel->sent_to_consumer = true;
        }
 
        /* Send streams */
        cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
-               if (!stream->fd) {
+               if (!stream->fd || stream->sent_to_consumer) {
                        continue;
                }
 
@@ -340,6 +351,7 @@ int kernel_consumer_send_channel_stream(struct consumer_socket *sock,
                if (ret < 0) {
                        goto error;
                }
+               stream->sent_to_consumer = true;
        }
 
 error:
@@ -373,7 +385,7 @@ int kernel_consumer_send_session(struct consumer_socket *sock,
 
        DBG("Sending session stream to kernel consumer");
 
-       if (session->metadata_stream_fd >= 0) {
+       if (session->metadata_stream_fd >= 0 && session->metadata) {
                ret = kernel_consumer_add_metadata(sock, session, monitor);
                if (ret < 0) {
                        goto error;