Fix multiple error handling for UST tracing

[lttng-tools.git] / lttng-sessiond / ust-consumer.c

diff --git a/lttng-sessiond/ust-consumer.c b/lttng-sessiond/ust-consumer.c
index df569368ae04f2e8faafb1b9ebbfde069fc618aa..c02cbf96588c2c4701c7c9e9667c590582c1723e 100644 (file)
--- a/lttng-sessiond/ust-consumer.c
+++ b/lttng-sessiond/ust-consumer.c
@@ -23,18 +23,19 @@
 #include <unistd.h>
 
 #include <lttngerr.h>
+#include <lttng-ht.h>
 #include <lttng-share.h>
 #include <lttng-sessiond-comm.h>
 #include <lttng/lttng-consumer.h>
 
-#include "hashtable.h"
 #include "ust-consumer.h"
 
 /*
  * Send all stream fds of UST channel to the consumer.
  */
 static int send_channel_streams(int sock,
-               struct ust_app_channel *uchan)
+               struct ust_app_channel *uchan,
+               uid_t uid, gid_t gid)
 {
        int ret, fd;
        struct lttcomm_consumer_msg lum;
@@ -46,8 +47,11 @@ static int send_channel_streams(int sock,
        lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 
        /*
-        * We need to keep shm_fd open to make sure this key stays unique within
-        * the session daemon.
+        * We need to keep shm_fd open while we transfer the stream file
+        * descriptors to make sure this key stays unique within the
+        * session daemon. We can free the channel shm_fd without
+        * problem after we finished sending stream fds for that
+        * channel.
         */
        lum.u.channel.channel_key = uchan->obj->shm_fd;
        lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
@@ -81,6 +85,8 @@ static int send_channel_streams(int sock,
                 */
                lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
                lum.u.stream.mmap_len = stream->obj->memory_map_size;
+               lum.u.stream.uid = uid;
+               lum.u.stream.gid = gid;
                strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
                lum.u.stream.path_name[PATH_MAX - 1] = '\0';
                DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
@@ -97,18 +103,7 @@ static int send_channel_streams(int sock,
                        perror("send consumer stream ancillary data");
                        goto error;
                }
-
-               /*
-                * We release the stream object here, as we have passed
-                * it to the consumer.
-                */
-               /* Ensure we don't let the app know (sock = -1). */
-               ustctl_release_object(-1, stream->obj);
-               cds_list_del(&stream->list);
-               free(stream);
        }
-       /* Ensure we don't let the app know (sock = -1). */
-       ustctl_release_object(-1, uchan->obj);
 
        DBG("consumer channel streams sent");
 
@@ -125,13 +120,17 @@ int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
 {
        int ret = 0;
        int sock = consumer_fd;
-       struct cds_lfht_iter iter;
-       struct cds_lfht_node *node;
+       struct lttng_ht_iter iter;
        struct lttcomm_consumer_msg lum;
-       struct ust_app_channel *uchan;
+       struct ust_app_channel *ua_chan;
 
        DBG("Sending metadata stream fd");
 
+       if (consumer_fd < 0) {
+               ERR("Consumer has negative file descriptor");
+               return -EINVAL;
+       }
+
        if (usess->metadata->obj->shm_fd != 0) {
                int fd;
                int fds[2];
@@ -161,6 +160,8 @@ int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
                lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
                lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
                lum.u.stream.mmap_len = usess->metadata->stream_obj->memory_map_size;
+               lum.u.stream.uid = usess->uid;
+               lum.u.stream.gid = usess->gid;
                strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
                lum.u.stream.path_name[PATH_MAX - 1] = '\0';
                DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
@@ -176,24 +177,17 @@ int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
                        perror("send consumer stream");
                        goto error;
                }
-               /* Metadata fds passed to consumer, release them. */
-               /* Ensure we don't let the app know (sock = -1). */
-               ustctl_release_object(-1, usess->metadata->stream_obj);
-               ustctl_release_object(-1, usess->metadata->obj);
        }
 
        /* Send each channel fd streams of session */
        rcu_read_lock();
-       hashtable_get_first(usess->channels, &iter);
-       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
-               uchan = caa_container_of(node, struct ust_app_channel, node);
-
-               ret = send_channel_streams(sock, uchan);
+       cds_lfht_for_each_entry(usess->channels->ht, &iter.iter, ua_chan,
+                       node.node) {
+               ret = send_channel_streams(sock, ua_chan, usess->uid, usess->gid);
                if (ret < 0) {
                        rcu_read_unlock();
                        goto error;
                }
-               hashtable_get_next(usess->channels, &iter);
        }
        rcu_read_unlock();