X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=3c9687306dc2aa2e904ef35f9954bdcc37e1d436;hp=bbc31f8e3be14bdb3927c87a1aabb40e28e777b5;hb=47e81c0236926bdee0423bf3f1e6ad3f1facc364;hpb=6e7423591c5edde632d79ff52ba449d99da8eb14

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index bbc31f8e3..3c9687306 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -49,7 +49,7 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 		struct lttng_consumer_stream *stream, unsigned long len)
 {
 	unsigned long mmap_offset;
-	ssize_t ret = 0;
+	ssize_t ret = 0, written = 0;
 	off_t orig_offset = stream->out_fd_offset;
 	int fd = stream->wait_fd;
 	int outfd = stream->out_fd;
@@ -59,30 +59,40 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 	if (ret != 0) {
 		errno = -ret;
 		perror("kernctl_get_mmap_read_offset");
+		written = ret;
 		goto end;
 	}
 
 	while (len > 0) {
 		ret = write(outfd, stream->mmap_base + mmap_offset, len);
-		if (ret >= len) {
-			len = 0;
-		} else if (ret < 0) {
-			errno = -ret;
+		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;
+			}
+		} else if (ret > len) {
 			perror("Error in file write");
+			written += ret;
 			goto end;
+		} else {
+			len -= ret;
+			mmap_offset += ret;
 		}
 		/* This won't block, but will start writeout asynchronously */
 		lttng_sync_file_range(outfd, stream->out_fd_offset, ret,
 				SYNC_FILE_RANGE_WRITE);
 		stream->out_fd_offset += ret;
+		written += ret;
 	}
-
 	lttng_consumer_sync_trace_file(stream, orig_offset);
-
-	goto end;
-
 end:
-	return ret;
+	return written;
 }
 
 /*
@@ -94,7 +104,7 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 		struct lttng_consumer_local_data *ctx,
 		struct lttng_consumer_stream *stream, unsigned long len)
 {
-	ssize_t ret = 0;
+	ssize_t ret = 0, written = 0;
 	loff_t offset = 0;
 	off_t orig_offset = stream->out_fd_offset;
 	int fd = stream->wait_fd;
@@ -107,8 +117,11 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 				SPLICE_F_MOVE | SPLICE_F_MORE);
 		DBG("splice chan to pipe ret %zd", ret);
 		if (ret < 0) {
-			errno = -ret;
 			perror("Error in relay splice");
+			if (written == 0) {
+				written = ret;
+			}
+			ret = errno;
 			goto splice_error;
 		}
 
@@ -116,8 +129,18 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 				SPLICE_F_MOVE | SPLICE_F_MORE);
 		DBG("splice pipe to file %zd", ret);
 		if (ret < 0) {
-			errno = -ret;
 			perror("Error in file splice");
+			if (written == 0) {
+				written = ret;
+			}
+			ret = errno;
+			goto splice_error;
+		}
+		if (ret > len) {
+			errno = EINVAL;
+			perror("Wrote more data than requested");
+			written += ret;
+			ret = errno;
 			goto splice_error;
 		}
 		len -= ret;
@@ -125,6 +148,7 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 		lttng_sync_file_range(outfd, stream->out_fd_offset, ret,
 				SYNC_FILE_RANGE_WRITE);
 		stream->out_fd_offset += ret;
+		written += ret;
 	}
 	lttng_consumer_sync_trace_file(stream, orig_offset);
 
@@ -132,7 +156,7 @@ ssize_t lttng_kconsumer_on_read_subbuffer_splice(
 
 splice_error:
 	/* send the appropriate error description to sessiond */
-	switch(ret) {
+	switch (ret) {
 	case EBADF:
 		lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EBADF);
 		break;
@@ -148,7 +172,7 @@ splice_error:
 	}
 
 end:
-	return ret;
+	return written;
 }
 
 /*
@@ -351,13 +375,14 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 
 			/* splice the subbuffer to the tracefile */
 			ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len);
-			if (ret < 0) {
+			if (ret != len) {
 				/*
 				 * display the error but continue processing to try
 				 * to release the subbuffer
 				 */
 				ERR("Error splicing to tracefile");
 			}
+
 			break;
 		case LTTNG_EVENT_MMAP:
 			/* read the used subbuffer size */
@@ -369,7 +394,7 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 			}
 			/* write the subbuffer to the tracefile */
 			ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
-			if (ret < 0) {
+			if (ret != len) {
 				/*
 				 * display the error but continue processing to try
 				 * to release the subbuffer