SoW-2020-0002: Trace Hit Counters: trigger error reporting integration
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
index 6a561b4ca7b3be844c7ae2d306b70b473da9eebb..cd9b273c28f32f36be201df68263100a11c7b7bb 100644 (file)
@@ -37,6 +37,7 @@
 #include <common/utils.h>
 #include <common/index/index.h>
 #include <common/consumer/consumer.h>
+#include <common/shm.h>
 #include <common/optional.h>
 
 #include "ust-consumer.h"
@@ -78,6 +79,11 @@ static void destroy_channel(struct lttng_consumer_channel *channel)
                lttng_ustconsumer_del_channel(channel);
                lttng_ustconsumer_free_channel(channel);
        }
+
+       if (channel->trace_chunk) {
+               lttng_trace_chunk_put(channel->trace_chunk);
+       }
+
        free(channel);
 }
 
@@ -347,48 +353,6 @@ error_alloc:
        return ret;
 }
 
-/*
- * create_posix_shm is never called concurrently within a process.
- */
-static
-int create_posix_shm(void)
-{
-       char tmp_name[NAME_MAX];
-       int shmfd, ret;
-
-       ret = snprintf(tmp_name, NAME_MAX, "/ust-shm-consumer-%d", getpid());
-       if (ret < 0) {
-               PERROR("snprintf");
-               return -1;
-       }
-       /*
-        * Allocate shm, and immediately unlink its shm oject, keeping
-        * only the file descriptor as a reference to the object.
-        * We specifically do _not_ use the / at the beginning of the
-        * pathname so that some OS implementations can keep it local to
-        * the process (POSIX leaves this implementation-defined).
-        */
-       shmfd = shm_open(tmp_name, O_CREAT | O_EXCL | O_RDWR, 0700);
-       if (shmfd < 0) {
-               PERROR("shm_open");
-               goto error_shm_open;
-       }
-       ret = shm_unlink(tmp_name);
-       if (ret < 0 && errno != ENOENT) {
-               PERROR("shm_unlink");
-               goto error_shm_release;
-       }
-       return shmfd;
-
-error_shm_release:
-       ret = close(shmfd);
-       if (ret) {
-               PERROR("close");
-       }
-error_shm_open:
-       return -1;
-}
-
 static int open_ust_stream_fd(struct lttng_consumer_channel *channel, int cpu,
                const struct lttng_credentials *session_credentials)
 {
@@ -396,7 +360,7 @@ static int open_ust_stream_fd(struct lttng_consumer_channel *channel, int cpu,
        int ret;
 
        if (!channel->shm_path[0]) {
-               return create_posix_shm();
+               return shm_create_anonymous("ust-consumer");
        }
        ret = get_stream_shm_path(shm_path, channel->shm_path, cpu);
        if (ret) {
@@ -404,7 +368,8 @@ static int open_ust_stream_fd(struct lttng_consumer_channel *channel, int cpu,
        }
        return run_as_open(shm_path,
                O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR,
-               session_credentials->uid, session_credentials->gid);
+               lttng_credentials_get_uid(session_credentials),
+               lttng_credentials_get_gid(session_credentials));
 
 error_shm_path:
        return -1;
@@ -482,8 +447,10 @@ error_open:
                                ERR("Cannot get stream shm path");
                        }
                        closeret = run_as_unlink(shm_path,
-                                       channel->buffer_credentials.value.uid,
-                                       channel->buffer_credentials.value.gid);
+                                       lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+                                                       channel->buffer_credentials)),
+                                       lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+                                                       channel->buffer_credentials)));
                        if (closeret) {
                                PERROR("unlink %s", shm_path);
                        }
@@ -492,8 +459,10 @@ error_open:
        /* Try to rmdir all directories under shm_path root. */
        if (channel->root_shm_path[0]) {
                (void) run_as_rmdir_recursive(channel->root_shm_path,
-                               channel->buffer_credentials.value.uid,
-                               channel->buffer_credentials.value.gid,
+                               lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+                                               channel->buffer_credentials)),
+                               lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+                                               channel->buffer_credentials)),
                                LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG);
        }
        free(stream_fds);
@@ -1456,8 +1425,8 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                struct ustctl_consumer_channel_attr attr;
                const uint64_t chunk_id = msg.u.ask_channel.chunk_id.value;
                const struct lttng_credentials buffer_credentials = {
-                       .uid = msg.u.ask_channel.buffer_credentials.uid,
-                       .gid = msg.u.ask_channel.buffer_credentials.gid,
+                       .uid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.ask_channel.buffer_credentials.uid),
+                       .gid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.ask_channel.buffer_credentials.gid),
                };
 
                /* Create a plain object and reserve a channel key. */
@@ -2067,8 +2036,8 @@ end_rotate_channel_nosignal:
        case LTTNG_CONSUMER_CREATE_TRACE_CHUNK:
        {
                const struct lttng_credentials credentials = {
-                       .uid = msg.u.create_trace_chunk.credentials.value.uid,
-                       .gid = msg.u.create_trace_chunk.credentials.value.gid,
+                       .uid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.create_trace_chunk.credentials.value.uid),
+                       .gid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.create_trace_chunk.credentials.value.gid),
                };
                const bool is_local_trace =
                                !msg.u.create_trace_chunk.relayd_id.is_set;
@@ -2176,6 +2145,28 @@ end_rotate_channel_nosignal:
                                msg.u.trace_chunk_exists.chunk_id);
                goto end_msg_sessiond;
        }
+       case LTTNG_CONSUMER_OPEN_CHANNEL_PACKETS:
+       {
+               const uint64_t key = msg.u.open_channel_packets.key;
+               struct lttng_consumer_channel *channel =
+                               consumer_find_channel(key);
+
+               if (channel) {
+                       pthread_mutex_lock(&channel->lock);
+                       ret_code = lttng_consumer_open_channel_packets(channel);
+                       pthread_mutex_unlock(&channel->lock);
+               } else {
+                       /*
+                        * The channel could have disappeared in per-pid
+                        * buffering mode.
+                        */
+                       DBG("Channel %" PRIu64 " not found", key);
+                       ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+               }
+
+               health_code_update();
+               goto end_msg_sessiond;
+       }
        default:
                break;
        }
@@ -2375,8 +2366,10 @@ void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
                                ERR("Cannot get stream shm path");
                        }
                        ret = run_as_unlink(shm_path,
-                                       chan->buffer_credentials.value.uid,
-                                       chan->buffer_credentials.value.gid);
+                                       lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+                                                       chan->buffer_credentials)),
+                                       lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+                                                       chan->buffer_credentials)));
                        if (ret) {
                                PERROR("unlink %s", shm_path);
                        }
@@ -2395,8 +2388,10 @@ void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan)
        /* Try to rmdir all directories under shm_path root. */
        if (chan->root_shm_path[0]) {
                (void) run_as_rmdir_recursive(chan->root_shm_path,
-                               chan->buffer_credentials.value.uid,
-                               chan->buffer_credentials.value.gid,
+                               lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+                                               chan->buffer_credentials)),
+                               lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+                                               chan->buffer_credentials)),
                                LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG);
        }
        free(chan->stream_fds);
@@ -2441,8 +2436,8 @@ void metadata_stream_reset_cache_consumed_position(
 /*
  * Write up to one packet from the metadata cache to the channel.
  *
- * Returns the number of bytes pushed in the cache, or a negative value
- * on error.
+ * Returns the number of bytes pushed from the cache into the ring buffer, or a
+ * negative value on error.
  */
 static
 int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
@@ -2526,15 +2521,13 @@ end:
  * awaiting on metadata to be pushed out.
  *
  * The RCU read side lock must be held by the caller.
- *
- * Return 0 if new metadatda is available, EAGAIN if the metadata stream
- * is empty or a negative value on error.
  */
-int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
+enum sync_metadata_status lttng_ustconsumer_sync_metadata(
+               struct lttng_consumer_local_data *ctx,
                struct lttng_consumer_stream *metadata_stream)
 {
        int ret;
-       int retry = 0;
+       enum sync_metadata_status status;
        struct lttng_consumer_channel *metadata_channel;
 
        assert(ctx);
@@ -2549,6 +2542,7 @@ int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
        ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 0);
        pthread_mutex_lock(&metadata_stream->lock);
        if (ret < 0) {
+               status = SYNC_METADATA_STATUS_ERROR;
                goto end;
        }
 
@@ -2566,38 +2560,30 @@ int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
        if (consumer_stream_is_deleted(metadata_stream)) {
                DBG("Metadata stream %" PRIu64 " was deleted during the metadata synchronization",
                                metadata_stream->key);
-               ret = 0;
+               status = SYNC_METADATA_STATUS_NO_DATA;
                goto end;
        }
 
        ret = commit_one_metadata_packet(metadata_stream);
-       if (ret <= 0) {
+       if (ret < 0) {
+               status = SYNC_METADATA_STATUS_ERROR;
                goto end;
        } else if (ret > 0) {
-               retry = 1;
+               status = SYNC_METADATA_STATUS_NEW_DATA;
+       } else /* ret == 0 */ {
+               status = SYNC_METADATA_STATUS_NO_DATA;
+               goto end;
        }
 
        ret = ustctl_snapshot(metadata_stream->ustream);
        if (ret < 0) {
-               if (errno != EAGAIN) {
-                       ERR("Sync metadata, taking UST snapshot");
-                       goto end;
-               }
-               DBG("No new metadata when syncing them.");
-               /* No new metadata, exit. */
-               ret = ENODATA;
+               ERR("Failed to take a snapshot of the metadata ring-buffer positions, ret = %d", ret);
+               status = SYNC_METADATA_STATUS_ERROR;
                goto end;
        }
 
-       /*
-        * After this flush, we still need to extract metadata.
-        */
-       if (retry) {
-               ret = EAGAIN;
-       }
-
 end:
-       return ret;
+       return status;
 }
 
 /*
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