Fix: kernel ctl error codes are based on errno
[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c
index 42af65ac3d8c715a8a0851cd44dfdb54f9278072..bfec4d2f0db343c067c288f62f42d426ed88afb6 100644 (file)
@@ -57,8 +57,8 @@ int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream)
 
        ret = kernctl_snapshot(infd);
        if (ret != 0) {
-               errno = -ret;
                perror("Getting sub-buffer snapshot.");
+               ret = -errno;
        }
 
        return ret;
@@ -77,8 +77,8 @@ int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 
        ret = kernctl_snapshot_get_produced(infd, pos);
        if (ret != 0) {
-               errno = -ret;
                perror("kernctl_snapshot_get_produced");
+               ret = -errno;
        }
 
        return ret;
@@ -97,8 +97,8 @@ int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
 
        ret = kernctl_snapshot_get_consumed(infd, pos);
        if (ret != 0) {
-               errno = -ret;
                perror("kernctl_snapshot_get_consumed");
+               ret = -errno;
        }
 
        return ret;
@@ -110,20 +110,21 @@ int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
  * Returns 0 on success, < 0 on error
  */
 int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
-               uint64_t relayd_id, struct lttng_consumer_local_data *ctx)
+               uint64_t relayd_id, uint64_t max_stream_size,
+               struct lttng_consumer_local_data *ctx)
 {
        int ret;
        unsigned long consumed_pos, produced_pos;
        struct lttng_consumer_channel *channel;
        struct lttng_consumer_stream *stream;
 
-       DBG("Kernel consumer snapshot channel %lu", key);
+       DBG("Kernel consumer snapshot channel %" PRIu64, key);
 
        rcu_read_lock();
 
        channel = consumer_find_channel(key);
        if (!channel) {
-               ERR("No channel found for key %lu", key);
+               ERR("No channel found for key %" PRIu64, key);
                ret = -1;
                goto end;
        }
@@ -166,13 +167,14 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        stream->out_fd = ret;
                        stream->tracefile_size_current = 0;
 
-                       DBG("Kernel consumer snapshot stream %s/%s (%lu)", path,
-                                       stream->name, stream->key);
+                       DBG("Kernel consumer snapshot stream %s/%s (%" PRIu64 ")",
+                                       path, stream->name, stream->key);
                }
 
                ret = kernctl_buffer_flush(stream->wait_fd);
                if (ret < 0) {
                        ERR("Failed to flush kernel stream");
+                       ret = -errno;
                        goto end_unlock;
                }
 
@@ -199,10 +201,20 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                                        &stream->max_sb_size);
                        if (ret < 0) {
                                ERR("Getting kernel max_sb_size");
+                               ret = -errno;
                                goto end_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;
@@ -213,6 +225,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        if (ret < 0) {
                                if (errno != EAGAIN) {
                                        PERROR("kernctl_get_subbuf snapshot");
+                                       ret = -errno;
                                        goto end_unlock;
                                }
                                DBG("Kernel consumer get subbuf failed. Skipping it.");
@@ -223,12 +236,14 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        ret = kernctl_get_subbuf_size(stream->wait_fd, &len);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_get_subbuf_size");
+                               ret = -errno;
                                goto error_put_subbuf;
                        }
 
                        ret = kernctl_get_padded_subbuf_size(stream->wait_fd, &padded_len);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_get_padded_subbuf_size");
+                               ret = -errno;
                                goto error_put_subbuf;
                        }
 
@@ -254,6 +269,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        ret = kernctl_put_subbuf(stream->wait_fd);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_put_subbuf");
+                               ret = -errno;
                                goto end_unlock;
                        }
                        consumed_pos += stream->max_sb_size;
@@ -282,6 +298,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 error_put_subbuf:
        ret = kernctl_put_subbuf(stream->wait_fd);
        if (ret < 0) {
+               ret = -errno;
                ERR("Snapshot kernctl_put_subbuf error path");
        }
 end_unlock:
@@ -345,8 +362,8 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
        do {
                ret_read = lttng_kconsumer_read_subbuffer(metadata_stream, ctx);
                if (ret_read < 0) {
-                       if (ret_read != -EPERM) {
-                               ERR("Kernel snapshot reading metadata subbuffer (ret: %ld)",
+                       if (ret_read != -EAGAIN) {
+                               ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
                                                ret_read);
                                goto error;
                        }
@@ -643,21 +660,40 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
                /* Get the right pipe where the stream will be sent. */
                if (new_stream->metadata_flag) {
+                       ret = consumer_add_metadata_stream(new_stream);
+                       if (ret) {
+                               ERR("Consumer add metadata stream %" PRIu64 " failed. Continuing",
+                                               new_stream->key);
+                               consumer_stream_free(new_stream);
+                               goto end_nosignal;
+                       }
                        stream_pipe = ctx->consumer_metadata_pipe;
                } else {
+                       ret = consumer_add_data_stream(new_stream);
+                       if (ret) {
+                               ERR("Consumer add stream %" PRIu64 " failed. Continuing",
+                                               new_stream->key);
+                               consumer_stream_free(new_stream);
+                               goto end_nosignal;
+                       }
                        stream_pipe = ctx->consumer_data_pipe;
                }
 
+               /* Vitible to other threads */
+               new_stream->globally_visible = 1;
+
                ret = lttng_pipe_write(stream_pipe, &new_stream, sizeof(new_stream));
                if (ret < 0) {
                        ERR("Consumer write %s stream to pipe %d",
                                        new_stream->metadata_flag ? "metadata" : "data",
                                        lttng_pipe_get_writefd(stream_pipe));
-                       consumer_stream_free(new_stream);
+                       if (new_stream->metadata_flag) {
+                               consumer_del_stream_for_metadata(new_stream);
+                       } else {
+                               consumer_del_stream_for_data(new_stream);
+                       }
                        goto end_nosignal;
                }
-               /* Successfully sent to the right thread. */
-               new_stream->globally_visible = 1;
 
                DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64,
                                new_stream->name, fd, new_stream->relayd_stream_id);
@@ -739,7 +775,9 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                } else {
                        ret = lttng_kconsumer_snapshot_channel(msg.u.snapshot_channel.key,
                                        msg.u.snapshot_channel.pathname,
-                                       msg.u.snapshot_channel.relayd_id, ctx);
+                                       msg.u.snapshot_channel.relayd_id,
+                                       msg.u.snapshot_channel.max_stream_size,
+                                       ctx);
                        if (ret < 0) {
                                ERR("Snapshot channel failed");
                                ret_code = LTTNG_ERR_KERN_CHAN_FAIL;
@@ -820,7 +858,6 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
        /* Get the next subbuffer */
        err = kernctl_get_next_subbuf(infd);
        if (err != 0) {
-               ret = err;
                /*
                 * This is a debug message even for single-threaded consumer,
                 * because poll() have more relaxed criterions than get subbuf,
@@ -829,15 +866,15 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                 */
                DBG("Reserving sub buffer failed (everything is normal, "
                                "it is due to concurrency)");
+               ret = -errno;
                goto end;
        }
 
        /* Get the full subbuffer size including padding */
        err = kernctl_get_padded_subbuf_size(infd, &len);
        if (err != 0) {
-               errno = -err;
                perror("Getting sub-buffer len failed.");
-               ret = err;
+               ret = -errno;
                goto end;
        }
 
@@ -871,9 +908,8 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                /* Get subbuffer size without padding */
                err = kernctl_get_subbuf_size(infd, &subbuf_size);
                if (err != 0) {
-                       errno = -err;
                        perror("Getting sub-buffer len failed.");
-                       ret = err;
+                       ret = -errno;
                        goto end;
                }
 
@@ -903,20 +939,18 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                break;
        default:
                ERR("Unknown output method");
-               ret = -1;
+               ret = -EPERM;
        }
 
        err = kernctl_put_next_subbuf(infd);
        if (err != 0) {
-               errno = -err;
                if (errno == EFAULT) {
                        perror("Error in unreserving sub buffer\n");
                } else if (errno == EIO) {
                        /* Should never happen with newer LTTng versions */
                        perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
                }
-
-               ret = -err;
+               ret = -errno;
                goto end;
        }
 
@@ -951,8 +985,8 @@ int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 
                ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len);
                if (ret != 0) {
-                       errno = -ret;
                        PERROR("kernctl_get_mmap_len");
+                       ret = -errno;
                        goto error_close_fd;
                }
                stream->mmap_len = (size_t) mmap_len;
@@ -995,6 +1029,11 @@ int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream)
 
        assert(stream);
 
+       if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
+               ret = 0;
+               goto end;
+       }
+
        ret = kernctl_get_next_subbuf(stream->wait_fd);
        if (ret == 0) {
                /* There is still data so let's put back this subbuffer. */
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