[PATCH] blktrace: stop trace on SIGINT to allow drain

diff --git a/blktrace.c b/blktrace.c
index 51398db16490d3ae95fb7379befd0555d7fec8cf..4054dea1178bcab8537ce344a178517d374bcf0c 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -295,6 +295,17 @@ static int net_out_fd = -1;
 
 static void handle_sigint(__attribute__((__unused__)) int sig)
 {
+       struct device_information *dip;
+       int i;
+
+       /*
+        * stop trace so we can reap currently produced data
+        */
+       for_each_dip(dip, i) {
+               if (ioctl(dip->fd, BLKTRACESTOP) < 0)
+                       perror("BLKTRACESTOP");
+       }
+
        done = 1;
 }
 
@@ -373,8 +384,11 @@ static void stop_trace(struct device_information *dip)
        if (dip_tracing(dip) || kill_running_trace) {
                dip_set_tracing(dip, 0);
 
-               if (ioctl(dip->fd, BLKTRACESTOP) < 0)
-                       perror("BLKTRACESTOP");
+               /*
+                * should be stopped, just don't complain if it isn't
+                */
+               ioctl(dip->fd, BLKTRACESTOP);
+
                if (ioctl(dip->fd, BLKTRACETEARDOWN) < 0)
                        perror("BLKTRACETEARDOWN");
 
@@ -564,7 +578,8 @@ static int get_subbuf(struct thread_information *tip, unsigned int maxlen)
        if (ret > 0) {
                ts->len = ret;
                tip->data_read += ret;
-               return subbuf_fifo_queue(tip, ts);
+               if (subbuf_fifo_queue(tip, ts))
+                       return -1;
        }
 
        return ret;
@@ -575,8 +590,7 @@ static int get_subbuf_sendfile(struct thread_information *tip,
 {
        struct tip_subbuf *ts;
        struct stat sb;
-       unsigned int ready, this_size;
-       int err;
+       unsigned int ready, this_size, total;
 
        wait_for_data(tip);
 
@@ -588,13 +602,13 @@ static int get_subbuf_sendfile(struct thread_information *tip,
 
        if (fstat(tip->fd, &sb) < 0) {
                perror("trace stat");
-               return 1;
+               return -1;
        }
 
        ready = sb.st_size - tip->ofile_offset;
        if (!ready) {
                /*
-                * delay a little, since we poll() will return data available
+                * delay a little, since poll() will return data available
                 * until sendfile() is run
                 */
                usleep(100);
@@ -602,28 +616,27 @@ static int get_subbuf_sendfile(struct thread_information *tip,
        }
 
        this_size = buf_size;
+       total = ready;
        while (ready) {
                if (this_size > ready)
                        this_size = ready;
 
                ts = malloc(sizeof(*ts));
 
-               ts->max_len = maxlen;
                ts->buf = NULL;
+               ts->max_len = 0;
 
                ts->len = this_size;
-               ts->max_len = ts->len;
                ts->offset = tip->ofile_offset;
                tip->ofile_offset += ts->len;
 
-               err = subbuf_fifo_queue(tip, ts);
-               if (err)
-                       return err;
+               if (subbuf_fifo_queue(tip, ts))
+                       return -1;
 
                ready -= this_size;
        }
 
-       return 0;
+       return total;
 }
 
 static void close_thread(struct thread_information *tip)
@@ -703,10 +716,16 @@ static void *thread_main(void *arg)
        }
 
        while (!is_done()) {
-               if (tip->get_subbuf(tip, buf_size))
+               if (tip->get_subbuf(tip, buf_size) < 0)
                        break;
        }
 
+       /*
+        * trace is stopped, pull data until we get a short read
+        */
+       while (tip->get_subbuf(tip, buf_size) > 0)
+               ;
+
        tip_ftrunc_final(tip);
        tip->exited = 1;
        return NULL;