X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=551d8579a21ad4c6e86bed6904df6290c4304d24;hb=b0b335c8c5a963f24dbedb4e597f23ed66c5b915;hp=8ed279f44e16db7e73a14d8947c9e87b143f6946;hpb=00e2e675d54dc726a7c8f8887c889cc8ef022003;p=lttng-tools.git

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 8ed279f44..551d8579a 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -59,6 +59,9 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 	uint64_t metadata_id;
 	struct consumer_relayd_sock_pair *relayd = NULL;
 
+	/* RCU lock for the relayd pointer */
+	rcu_read_lock();
+
 	/* Flag that the current stream if set for network streaming. */
 	if (stream->net_seq_idx != -1) {
 		relayd = consumer_find_relayd(stream->net_seq_idx);
@@ -76,9 +79,6 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 		goto end;
 	}
 
-	/* RCU lock for the relayd pointer */
-	rcu_read_lock();
-
 	/* Handle stream on the relayd if the output is on the network */
 	if (relayd) {
 		/*
@@ -101,12 +101,12 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 				do {
 					ret = write(outfd, (void *) &metadata_id,
 							sizeof(stream->relayd_stream_id));
-					if (ret < 0) {
-						PERROR("write metadata stream id");
-						written = ret;
-						goto end;
-					}
-				} while (errno == EINTR);
+				} while (ret < 0 && errno == EINTR);
+				if (ret < 0) {
+					PERROR("write metadata stream id");
+					written = ret;
+					goto end;
+				}
 				DBG("Metadata stream id %zu written before data",
 						stream->relayd_stream_id);
 				/*
@@ -120,18 +120,15 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 	}
 
 	while (len > 0) {
-		ret = write(outfd, stream->mmap_base + mmap_offset, len);
+		do {
+			ret = write(outfd, stream->mmap_base + mmap_offset, len);
+		} while (ret < 0 && errno == EINTR);
 		if (ret < 0) {
-			if (errno == EINTR) {
-				/* restart the interrupted system call */
-				continue;
-			} else {
-				perror("Error in file write");
-				if (written == 0) {
-					written = ret;
-				}
-				goto end;
+			perror("Error in file write");
+			if (written == 0) {
+				written = ret;
 			}
+			goto end;
 		} else if (ret > len) {
 			perror("Error in file write");
 			written += ret;
@@ -181,6 +178,9 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 	uint64_t metadata_id;
 	struct consumer_relayd_sock_pair *relayd = NULL;
 
+	/* RCU lock for the relayd pointer */
+	rcu_read_lock();
+
 	/* Flag that the current stream if set for network streaming. */
 	if (stream->net_seq_idx != -1) {
 		relayd = consumer_find_relayd(stream->net_seq_idx);
@@ -189,9 +189,6 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 		}
 	}
 
-	/* RCU lock for the relayd pointer */
-	rcu_read_lock();
-
 	/* Write metadata stream id before payload */
 	if (stream->metadata_flag && relayd) {
 		/*
@@ -200,17 +197,17 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 		 */
 		pthread_mutex_lock(&relayd->ctrl_sock_mutex);
 
+		metadata_id = htobe64(stream->relayd_stream_id);
 		do {
-			metadata_id = htobe64(stream->relayd_stream_id);
 			ret = write(ctx->consumer_thread_pipe[1],
 					(void *) &metadata_id,
 					sizeof(stream->relayd_stream_id));
-			if (ret < 0) {
-				PERROR("write metadata stream id");
-				written = ret;
-				goto end;
-			}
-		} while (errno == EINTR);
+		} while (ret < 0 && errno == EINTR);
+		if (ret < 0) {
+			PERROR("write metadata stream id");
+			written = ret;
+			goto end;
+		}
 		DBG("Metadata stream id %zu written before data",
 				stream->relayd_stream_id);
 	}
@@ -377,6 +374,9 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 		return -ENOENT;
 	}
 
+	/* relayd needs RCU read-side protection */
+	rcu_read_lock();
+
 	switch (msg.cmd_type) {
 	case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
 	{
@@ -581,8 +581,9 @@ end:
 	 */
 	do {
 		ret = write(ctx->consumer_poll_pipe[1], "", 1);
-	} while (ret == -1UL && errno == EINTR);
+	} while (ret < 0 && errno == EINTR);
 end_nosignal:
+	rcu_read_unlock();
 	return 0;
 }