Implement --shm-path option for UST sessions (per-uid channels)

[lttng-tools.git] / src / bin / lttng / commands / create.c

diff --git a/src/bin/lttng/commands/create.c b/src/bin/lttng/commands/create.c
index 1ebe590ad279915e8e3e7ba05784e0333eb9064f..b8d9f3b5655c56975bfa1716a08065b86ca1ca14 100644 (file)
--- a/src/bin/lttng/commands/create.c
+++ b/src/bin/lttng/commands/create.c
@@ -44,6 +44,7 @@ static char *opt_session_name;
 static char *opt_url;
 static char *opt_ctrl_url;
 static char *opt_data_url;
+static char *opt_shm_path;
 static int opt_no_consumer;
 static int opt_no_output;
 static int opt_snapshot;
@@ -69,6 +70,7 @@ static struct poptOption long_options[] = {
        {"no-consumer",     0, POPT_ARG_VAL, &opt_no_consumer, 1, 0, 0},
        {"snapshot",        0, POPT_ARG_VAL, &opt_snapshot, 1, 0, 0},
        {"live",            0, POPT_ARG_INT | POPT_ARGFLAG_OPTIONAL, 0, OPT_LIVE_TIMER, 0, 0},
+       {"shm-path",        0, POPT_ARG_STRING, &opt_shm_path, 0, 0, 0},
        {0, 0, 0, 0, 0, 0, 0}
 };
 
@@ -106,6 +108,9 @@ static void usage(FILE *ofp)
        fprintf(ofp, "                       By default, %u is used for the timer and the\n",
                                                                                        DEFAULT_LTTNG_LIVE_TIMER);
        fprintf(ofp, "                       network URL is set to net://127.0.0.1.\n");
+       fprintf(ofp, "      --shm-path PATH  Path where shared memory holding buffers\n");
+       fprintf(ofp, "                       should be created. Useful when used with pramfs\n");
+       fprintf(ofp, "                       to extract trace data after crash.\n");
        fprintf(ofp, "\n");
        fprintf(ofp, "Extended Options:\n");
        fprintf(ofp, "\n");
@@ -297,6 +302,7 @@ static int create_session(void)
        char session_name_date[NAME_MAX + 17], *print_str_url = NULL;
        time_t rawtime;
        struct tm *timeinfo;
+       char shm_path[PATH_MAX] = "";
 
        /* Get date and time for automatic session name/path */
        time(&rawtime);
@@ -481,6 +487,21 @@ static int create_session(void)
                }
        }
 
+       if (opt_shm_path) {
+               ret = snprintf(shm_path, sizeof(shm_path),
+                               "%s/%s", opt_shm_path, session_name_date);
+               if (ret < 0) {
+                       PERROR("snprintf shm_path");
+                       goto error;
+               }
+
+               ret = lttng_set_session_shm_path(session_name, shm_path);
+               if (ret < 0) {
+                       lttng_destroy_session(session_name);
+                       goto error;
+               }
+       }
+
        MSG("Session %s created.", session_name);
        if (print_str_url && !opt_snapshot) {
                MSG("Traces will be written in %s", print_str_url);
@@ -495,6 +516,10 @@ static int create_session(void)
                MSG("Snapshot mode set. Every channel enabled for that session will "
                                "be set in overwrite mode and mmap output.");
        }
+       if (opt_shm_path) {
+               MSG("Session %s set to shm_path: %s.", session_name,
+                       shm_path);
+       }
 
        /* Mi output */
        if (lttng_opt_mi) {