From ddf2284295cd4ee05d01dd3157b6f7c6ba20292c Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@suse.de>
Date: Thu, 16 Feb 2006 20:07:00 +0100
Subject: [PATCH] [PATCH] blktrace: don't truncate/open local files when in net
 client mode

---
 blktrace.c | 88 +++++++++++++++++++++++++++++-------------------------
 1 file changed, 47 insertions(+), 41 deletions(-)

diff --git a/blktrace.c b/blktrace.c
index 3cecc1e..1520029 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -541,7 +541,6 @@ static int get_subbuf_sendfile(struct thread_information *tip,
 	struct tip_subbuf *ts = malloc(sizeof(*ts));
 	struct stat sb;
 
-	ts->buf = malloc(buf_size);
 	ts->max_len = maxlen;
 	ts->buf = NULL;
 
@@ -928,48 +927,65 @@ static void fill_ops(struct thread_information *tip)
 		tip->read_data = read_data_file;
 }
 
-static int start_threads(struct device_information *dip)
+static int tip_open_output(struct device_information *dip,
+			   struct thread_information *tip)
 {
-	struct thread_information *tip;
-	int j, pipeline = output_name && !strcmp(output_name, "-");
+	int pipeline = output_name && !strcmp(output_name, "-");
 	int mode, vbuf_size;
 	char op[64];
 
-	for_each_tip(dip, tip, j) {
-		tip->cpu = j;
-		tip->device = dip;
-		tip->events_processed = 0;
-		memset(&tip->fifo, 0, sizeof(tip->fifo));
-		tip->leftover_ts = NULL;
-
-		if (pipeline) {
-			tip->ofile = fdopen(STDOUT_FILENO, "w");
-			tip->ofile_stdout = 1;
-			tip->ofile_mmap = 0;
-			mode = _IOLBF;
-			vbuf_size = 512;
-		} else {
-			fill_ofname(op, dip->buts_name, tip->cpu);
-			tip->ofile = fopen(op, "w+");
-			tip->ofile_stdout = 0;
-			tip->ofile_mmap = 1;
-			mode = _IOFBF;
-			vbuf_size = OFILE_BUF;
-		}
+	if (net_mode == Net_client) {
+		tip->ofile = NULL;
+		tip->ofile_stdout = 0;
+		tip->ofile_mmap = 0;
+		vbuf_size = 0;
+	} else if (pipeline) {
+		tip->ofile = fdopen(STDOUT_FILENO, "w");
+		tip->ofile_stdout = 1;
+		tip->ofile_mmap = 0;
+		mode = _IOLBF;
+		vbuf_size = 512;
+	} else {
+		fill_ofname(op, dip->buts_name, tip->cpu);
+		tip->ofile = fopen(op, "w+");
+		tip->ofile_stdout = 0;
+		tip->ofile_mmap = 1;
+		mode = _IOFBF;
+		vbuf_size = OFILE_BUF;
+	}
 
-		if (tip->ofile == NULL) {
-			perror(op);
-			return 1;
-		}
+	if (net_mode != Net_client && tip->ofile == NULL) {
+		perror(op);
+		return 1;
+	}
 
+	if (vbuf_size) {
 		tip->ofile_buffer = malloc(vbuf_size);
 		if (setvbuf(tip->ofile, tip->ofile_buffer, mode, vbuf_size)) {
 			perror("setvbuf");
 			close_thread(tip);
 			return 1;
 		}
+	}
+
+	fill_ops(tip);
+	return 0;
+}
 
-		fill_ops(tip);
+static int start_threads(struct device_information *dip)
+{
+	struct thread_information *tip;
+	int j;
+
+	for_each_tip(dip, tip, j) {
+		tip->cpu = j;
+		tip->device = dip;
+		tip->events_processed = 0;
+		memset(&tip->fifo, 0, sizeof(tip->fifo));
+		tip->leftover_ts = NULL;
+
+		if (tip_open_output(dip, tip))
+			return 1;
 
 		if (pthread_create(&tip->thread, NULL, thread_main, tip)) {
 			perror("pthread_create");
@@ -1166,22 +1182,12 @@ static struct device_information *net_get_dip(char *buts_name)
 	 */
 	for (i = 0; i < ncpus; i++) {
 		struct thread_information *tip = &dip->threads[i];
-		char op[64];
 
 		tip->cpu = i;
-		tip->ofile_stdout = 0;
-		tip->ofile_mmap = 1;
 		tip->device = dip;
 
-		fill_ops(tip);
-
-		fill_ofname(op, dip->buts_name, tip->cpu);
-
-		tip->ofile = fopen(op, "w+");
-		if (!tip->ofile) {
-			perror("fopen");
+		if (tip_open_output(dip, tip))
 			return NULL;
-		}
 	}
 
 	return dip;
-- 
2.25.1