From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 23 Jul 2012 15:13:40 +0000 (-0400)
Subject: fix: write EINTR handling
X-Git-Tag: v2.1.0-rc1~62
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=6f94560a050962daad560dac2823bd97b0b1bf98;p=lttng-tools.git

fix: write EINTR handling

Ensure that we always test for ret < 0 && errno == EINTR for each
write() call.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index 5a12ba888..0428d33ce 100644
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -246,7 +246,9 @@ int notify_thread_pipe(int wpipe)
 {
 	int ret;
 
-	ret = write(wpipe, "!", 1);
+	do {
+		ret = write(wpipe, "!", 1);
+	} while (ret < 0 && errno == EINTR);
 	if (ret < 0) {
 		PERROR("write poll pipe");
 	}
@@ -627,8 +629,10 @@ void *relay_thread_dispatcher(void *data)
 			 * call is blocking so we can be assured that the data will be read
 			 * at some point in time or wait to the end of the world :)
 			 */
-			ret = write(relay_cmd_pipe[1], relay_cmd,
-					sizeof(struct relay_command));
+			do {
+				ret = write(relay_cmd_pipe[1], relay_cmd,
+						sizeof(struct relay_command));
+			} while (ret < 0 && errno == EINTR);
 			free(relay_cmd);
 			if (ret < 0) {
 				PERROR("write cmd pipe");
@@ -1054,8 +1058,10 @@ int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
 		goto end;
 	}
 
-	ret = write(metadata_stream->fd, metadata_struct->payload,
-			payload_size);
+	do {
+		ret = write(metadata_stream->fd, metadata_struct->payload,
+				payload_size);
+	} while (ret < 0 && errno == EINTR);
 	if (ret < (payload_size)) {
 		ERR("Relay error writing metadata on file");
 		ret = -1;
@@ -1189,7 +1195,9 @@ int relay_process_data(struct relay_command *cmd, struct lttng_ht *streams_ht)
 		goto end;
 	}
 
-	ret = write(stream->fd, data_buffer, data_size);
+	do {
+		ret = write(stream->fd, data_buffer, data_size);
+	} while (ret < 0 && errno == EINTR);
 	if (ret < data_size) {
 		ERR("Relay error writing data to file");
 		ret = -1;
diff --git a/src/bin/lttng-sessiond/utils.c b/src/bin/lttng-sessiond/utils.c
index 07f29aded..d503665a4 100644
--- a/src/bin/lttng-sessiond/utils.c
+++ b/src/bin/lttng-sessiond/utils.c
@@ -31,7 +31,9 @@ int notify_thread_pipe(int wpipe)
 {
 	int ret;
 
-	ret = write(wpipe, "!", 1);
+	do {
+		ret = write(wpipe, "!", 1);
+	} while (ret < 0 && errno == EINTR);
 	if (ret < 0) {
 		PERROR("write poll pipe");
 	}
diff --git a/src/common/consumer.c b/src/common/consumer.c
index 88e8d9d28..974c65f55 100644
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -875,7 +875,9 @@ void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx)
 {
 	int ret;
 	consumer_quit = 1;
-	ret = write(ctx->consumer_should_quit[1], "4", 1);
+	do {
+		ret = write(ctx->consumer_should_quit[1], "4", 1);
+	} while (ret < 0 && errno == EINTR);
 	if (ret < 0) {
 		perror("write consumer quit");
 	}
@@ -1522,7 +1524,7 @@ end:
 	 */
 	do {
 		ret = write(ctx->consumer_poll_pipe[1], "", 1);
-	} while (ret == -1UL && errno == EINTR);
+	} while (ret < 0 && errno == EINTR);
 	rcu_unregister_thread();
 	return NULL;
 }
diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 8ed279f44..00bb7f721 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -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;
@@ -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);
 	}
@@ -581,7 +578,7 @@ end:
 	 */
 	do {
 		ret = write(ctx->consumer_poll_pipe[1], "", 1);
-	} while (ret == -1UL && errno == EINTR);
+	} while (ret < 0 && errno == EINTR);
 end_nosignal:
 	return 0;
 }
diff --git a/src/common/runas.c b/src/common/runas.c
index 3a89cc9ab..43b154f10 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -192,8 +192,10 @@ int child_run_as(void *_data)
 	writeleft = sizeof(sendret);
 	index = 0;
 	do {
-		writelen = write(data->retval_pipe, &sendret.c[index],
-				writeleft);
+		do {
+			writelen = write(data->retval_pipe, &sendret.c[index],
+					writeleft);
+		} while (writelen < 0 && errno == EINTR);
 		if (writelen < 0) {
 			PERROR("write");
 			return EXIT_FAILURE;
diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index f6add2c2c..1cd39ef34 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -91,12 +91,12 @@ ssize_t lttng_ustconsumer_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);
 			}
@@ -105,18 +105,15 @@ ssize_t lttng_ustconsumer_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("ret %ld > len %lu", ret, len);
 			written += ret;
@@ -434,7 +431,7 @@ end:
 	 */
 	do {
 		ret = write(ctx->consumer_poll_pipe[1], "", 1);
-	} while (ret == -1UL && errno == EINTR);
+	} while (ret < 0 && errno == EINTR);
 end_nosignal:
 	return 0;
 }