blkparse: split off the timestamp correction code in to a separate function

[blktrace.git] / blktrace.c

diff --git a/blktrace.c b/blktrace.c
index 3a25338cc9ad271a82fa30dbae1aa0ccb0e21cba..d0d271f9add5106b4481321058787f1ba1aa82a4 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -112,6 +112,7 @@ struct devpath {
        struct cl_host *ch;
        u32 cl_id;
        time_t cl_connect_time;
+       int setup_done; /* ioctl BLKTRACESETUP done */
        struct io_info *ios;
 };
 
@@ -1066,9 +1067,10 @@ static void close_client_connections(void)
        }
 }
 
-static void setup_buts(void)
+static int setup_buts(void)
 {
        struct list_head *p;
+       int ret = 0;
 
        __list_for_each(p, &devpaths) {
                struct blk_user_trace_setup buts;
@@ -1082,14 +1084,19 @@ static void setup_buts(void)
                if (ioctl(dpp->fd, BLKTRACESETUP, &buts) >= 0) {
                        dpp->ncpus = max_cpus;
                        dpp->buts_name = strdup(buts.name);
+                       dpp->setup_done = 1;
                        if (dpp->stats)
                                free(dpp->stats);
                        dpp->stats = calloc(dpp->ncpus, sizeof(*dpp->stats));
                        memset(dpp->stats, 0, dpp->ncpus * sizeof(*dpp->stats));
-               } else
+               } else {
                        fprintf(stderr, "BLKTRACESETUP(2) %s failed: %d/%s\n",
                                dpp->path, errno, strerror(errno));
+                       ret++;
+               }
        }
+
+       return ret;
 }
 
 static void start_buts(void)
@@ -1280,7 +1287,8 @@ static void rel_devpaths(void)
                struct devpath *dpp = list_entry(p, struct devpath, head);
 
                list_del(&dpp->head);
-               __stop_trace(dpp->fd);
+               if (dpp->setup_done)
+                       __stop_trace(dpp->fd);
                close(dpp->fd);
 
                if (dpp->heads)
@@ -1893,6 +1901,26 @@ static int start_tracer(int cpu)
        return 0;
 }
 
+static int create_output_files(int cpu)
+{
+       char fname[MAXPATHLEN + 64];
+       struct list_head *p;
+       FILE *f;
+
+       __list_for_each(p, &devpaths) {
+               struct devpath *dpp = list_entry(p, struct devpath, head);
+
+               if (fill_ofname(fname, sizeof(fname), NULL, dpp->buts_name,
+                               cpu))
+                       return 1;
+               f = my_fopen(fname, "w+");
+               if (!f)
+                       return 1;
+               fclose(f);
+       }
+       return 0;
+}
+
 static void start_tracers(void)
 {
        int cpu, started = 0;
@@ -1900,8 +1928,16 @@ static void start_tracers(void)
        size_t alloc_size = CPU_ALLOC_SIZE(max_cpus);
 
        for (cpu = 0; cpu < max_cpus; cpu++) {
-               if (!CPU_ISSET_S(cpu, alloc_size, online_cpus))
+               if (!CPU_ISSET_S(cpu, alloc_size, online_cpus)) {
+                       /*
+                        * Create fake empty output files so that other tools
+                        * like blkparse don't have to bother with sparse CPU
+                        * number space.
+                        */
+                       if (create_output_files(cpu))
+                               break;
                        continue;
+               }
                if (start_tracer(cpu))
                        break;
                started++;
@@ -2648,7 +2684,8 @@ static int run_tracers(void)
        if (net_mode == Net_client)
                printf("blktrace: connecting to %s\n", hostname);
 
-       setup_buts();
+       if (setup_buts())
+               return 1;
 
        if (use_tracer_devpaths()) {
                if (setup_tracer_devpaths())