[PATCH] blktrace fixes

- Threads don't close the trace fd
- Switch to newer /relay/block/<dev>/trace<cpu> naming

diff --git a/blktrace.c b/blktrace.c
index d3f2363a9d262cdb8d747cb4ba7a9bde5d249bae..78cdc8568e7c67f77865758d4f53fcc94158ca24 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -27,6 +27,7 @@
 #include <fcntl.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <sys/param.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sched.h>
@@ -101,6 +102,10 @@ struct option l_opts[] = {
 struct thread_information {
        int cpu;
        pthread_t thread;
+
+       int fd;
+       char fn[MAXPATHLEN + 64];
+
        unsigned long events_processed;
 };
 
@@ -174,8 +179,8 @@ static void stop_trace(void)
        close(devfd);
 }
 
-static void extract_data(int cpu, char *ifn, int ifd, char *ofn, int ofd,
-                        int nb)
+static void extract_data(struct thread_information *tip,
+                        char *ofn, int ofd, int nb)
 {
        int ret, bytes_left;
        unsigned char *buf, *p;
@@ -184,13 +189,13 @@ static void extract_data(int cpu, char *ifn, int ifd, char *ofn, int ofd,
        p = buf;
        bytes_left = nb;
        while (bytes_left > 0) {
-               ret = read(ifd, p, bytes_left);
+               ret = read(tip->fd, p, bytes_left);
                if (!ret)
                        usleep(1000);
                else if (ret < 0) {
-                       perror(ifn);
+                       perror(tip->fn);
                        fprintf(stderr, "Thread %d extract_data %s failed\n",
-                               cpu, ifn);
+                               tip->cpu, tip->fn);
                        free(buf);
                        exit(1);
                } else {
@@ -202,7 +207,7 @@ static void extract_data(int cpu, char *ifn, int ifd, char *ofn, int ofd,
        ret = write(ofd, buf, nb);
        if (ret != nb) {
                perror(ofn);
-               fprintf(stderr,"Thread %d extract_data %s failed\n", cpu, ofn);
+               fprintf(stderr,"Thread %d extract_data %s failed\n", tip->cpu, ofn);
                free(buf);
                exit(1);
        }
@@ -213,14 +218,14 @@ static void extract_data(int cpu, char *ifn, int ifd, char *ofn, int ofd,
 static void *extract(void *arg)
 {
        struct thread_information *tip = arg;
-       int tracefd, ret, ofd, pdu_len;
-       char ip[64], op[64];
+       int ret, ofd, pdu_len;
+       char op[64], dp[64];
        struct blk_io_trace t;
        pid_t pid = getpid();
        cpu_set_t cpu_mask;
 
        CPU_ZERO(&cpu_mask);
-       CPU_SET(tip->cpu, &cpu_mask);
+       CPU_SET((tip->cpu), &cpu_mask);
 
        if (sched_setaffinity(pid, sizeof(cpu_mask), &cpu_mask) == -1) {
                perror("sched_setaffinity");
@@ -235,25 +240,26 @@ static void *extract(void *arg)
                exit(1);
        }
 
-       sprintf(ip, "%s%s%d", relay_path, buts_name_p, tip->cpu);
-       tracefd = open(ip, O_RDONLY);
-       if (tracefd < 0) {
-               perror(ip);
-               fprintf(stderr,"Thread %d failed open of %s\n", tip->cpu, ip);
+       snprintf(tip->fn, sizeof(tip->fn),
+                "%s/block/%s/trace%d", relay_path, buts_name_p, tip->cpu);
+       tip->fd = open(tip->fn, O_RDONLY);
+       if (tip->fd < 0) {
+               perror(tip->fn);
+               fprintf(stderr,"Thread %d failed open of %s\n", tip->cpu, tip->fn);
                exit(1);
        }
 
        while (!is_done()) {
-               ret = read(tracefd, &t, sizeof(t));
+               ret = read(tip->fd, &t, sizeof(t));
                if (ret != sizeof(t)) {
                        if (ret < 0) {
-                               perror(ip);
+                               perror(tip->fn);
                                fprintf(stderr,"Thread %d failed read of %s\n",
-                                       tip->cpu, ip);
+                                       tip->cpu, tip->fn);
                                exit(1);
                        } else if (ret > 0) {
                                fprintf(stderr,"Thread %d misread %s %d,%d\n",
-                                       tip->cpu, ip, ret, (int)sizeof(t));
+                                       tip->cpu, tip->fn, ret, (int)sizeof(t));
                                exit(1);
                        } else {
                                usleep(10000);
@@ -277,7 +283,7 @@ static void *extract(void *arg)
                }
 
                if (pdu_len)
-                       extract_data(tip->cpu, ip, tracefd, op, ofd, pdu_len);
+                       extract_data(tip, dp, ofd, pdu_len);
 
                tip->events_processed++;
        }
@@ -321,6 +327,7 @@ static void stop_threads(void)
 
                if (pthread_join(tip->thread, (void *) &ret))
                        perror("thread_join");
+               close(tip->fd);
        }
 }
 
@@ -445,8 +452,8 @@ int main(int argc, char *argv[])
        while (!is_done())
                sleep(1);
 
-       stop_threads();
        stop_trace();
+       stop_threads();
        show_stats();
 
        return 0;