Docs: Add -f/--config option to lttng-sessiond man page
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
index 548cc43095b633bb09528085dfb878a5e99578f6..a569c04155a05fe23e61cc8596028771332c8995 100644 (file)
@@ -85,6 +85,7 @@ static char *opt_load_session_path;
 static pid_t ppid;          /* Parent PID for --sig-parent option */
 static pid_t child_ppid;    /* Internal parent PID use with daemonize. */
 static char *rundir;
+static int lockfile_fd = -1;
 
 /* Set to 1 when a SIGUSR1 signal is received. */
 static int recv_child_signal;
@@ -511,6 +512,27 @@ static void close_consumer_sockets(void)
        }
 }
 
+/*
+ * Generate the full lock file path using the rundir.
+ *
+ * Return the snprintf() return value thus a negative value is an error.
+ */
+static int generate_lock_file_path(char *path, size_t len)
+{
+       int ret;
+
+       assert(path);
+       assert(rundir);
+
+       /* Build lockfile path from rundir. */
+       ret = snprintf(path, len, "%s/" DEFAULT_LTTNG_SESSIOND_LOCKFILE, rundir);
+       if (ret < 0) {
+               PERROR("snprintf lockfile path");
+       }
+
+       return ret;
+}
+
 /*
  * Cleanup the daemon
  */
@@ -592,14 +614,6 @@ static void cleanup(void)
        DBG("Removing directory %s", path);
        (void) rmdir(path);
 
-       /*
-        * We do NOT rmdir rundir because there are other processes
-        * using it, for instance lttng-relayd, which can start in
-        * parallel with this teardown.
-        */
-
-       free(rundir);
-
        DBG("Cleaning up all sessions");
 
        /* Destroy session list mutex */
@@ -664,6 +678,34 @@ static void cleanup(void)
                free(load_info);
        }
 
+       /*
+        * Cleanup lock file by deleting it and finaly closing it which will
+        * release the file system lock.
+        */
+       if (lockfile_fd >= 0) {
+               char lockfile_path[PATH_MAX];
+
+               ret = generate_lock_file_path(lockfile_path, sizeof(lockfile_path));
+               if (ret > 0) {
+                       ret = remove(lockfile_path);
+                       if (ret < 0) {
+                               PERROR("remove lock file");
+                       }
+                       ret = close(lockfile_fd);
+                       if (ret < 0) {
+                               PERROR("close lock file");
+                       }
+               }
+       }
+
+       /*
+        * We do NOT rmdir rundir because there are other processes
+        * using it, for instance lttng-relayd, which can start in
+        * parallel with this teardown.
+        */
+
+       free(rundir);
+
        /* <fun> */
        DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
                        "Matthew, BEET driven development works!%c[%dm",
@@ -1071,7 +1113,7 @@ static void signal_consumer_condition(struct consumer_data *data, int state)
  */
 static void *thread_manage_consumer(void *data)
 {
-       int sock = -1, i, ret, pollfd, err = -1;
+       int sock = -1, i, ret, pollfd, err = -1, should_quit = 0;
        uint32_t revents, nb_fd;
        enum lttcomm_return_code code;
        struct lttng_poll_event events;
@@ -1229,6 +1271,15 @@ restart:
        /* Infinite blocking call, waiting for transmission */
 restart_poll:
        while (1) {
+               health_code_update();
+
+               /* Exit the thread because the thread quit pipe has been triggered. */
+               if (should_quit) {
+                       /* Not a health error. */
+                       err = 0;
+                       goto exit;
+               }
+
                health_poll_entry();
                ret = lttng_poll_wait(&events, -1);
                health_poll_exit();
@@ -1251,12 +1302,12 @@ restart_poll:
 
                        health_code_update();
 
-                       /* Thread quit pipe has been closed. Killing thread. */
-                       ret = sessiond_check_thread_quit_pipe(pollfd, revents);
-                       if (ret) {
-                               err = 0;
-                               goto exit;
-                       }
+                       /*
+                        * Thread quit pipe has been triggered, flag that we should stop
+                        * but continue the current loop to handle potential data from
+                        * consumer.
+                        */
+                       should_quit = sessiond_check_thread_quit_pipe(pollfd, revents);
 
                        if (pollfd == sock) {
                                /* Event on the consumerd socket */
@@ -1285,11 +1336,8 @@ restart_poll:
                                        ERR("Handling metadata request");
                                        goto error;
                                }
-                               break;
-                       } else {
-                               ERR("Unknown pollfd");
-                               goto error;
                        }
+                       /* No need for an else branch all FDs are tested prior. */
                }
                health_code_update();
        }
@@ -2974,6 +3022,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
                        }
 
                        /* 32-bit */
+                       pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
                        if (consumerd32_bin[0] != '\0' &&
                                        ustconsumer32_data.pid == 0 &&
                                        cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
@@ -3160,12 +3209,14 @@ skip_domain:
 
                        if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
                                ret = LTTNG_ERR_FILTER_INVAL;
+                               free(filter_expression);
                                free(exclusion);
                                goto error;
                        }
 
                        bytecode = zmalloc(bytecode_len);
                        if (!bytecode) {
+                               free(filter_expression);
                                free(exclusion);
                                ret = LTTNG_ERR_FILTER_NOMEM;
                                goto error;
@@ -3177,6 +3228,7 @@ skip_domain:
                        if (ret <= 0) {
                                DBG("Nothing recv() from client car len data... continuing");
                                *sock_error = 1;
+                               free(filter_expression);
                                free(bytecode);
                                free(exclusion);
                                ret = LTTNG_ERR_FILTER_INVAL;
@@ -3184,6 +3236,7 @@ skip_domain:
                        }
 
                        if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
+                               free(filter_expression);
                                free(bytecode);
                                free(exclusion);
                                ret = LTTNG_ERR_FILTER_INVAL;
@@ -3423,7 +3476,7 @@ skip_domain:
        case LTTNG_LIST_CHANNELS:
        {
                int nb_chan;
-               struct lttng_channel *channels;
+               struct lttng_channel *channels = NULL;
 
                nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
                                cmd_ctx->session, &channels);
@@ -4163,7 +4216,7 @@ static void usage(void)
        fprintf(stderr, "      --verbose-consumer             Verbose mode for consumer. Activate DBG() macro.\n");
        fprintf(stderr, "      --no-kernel                    Disable kernel tracer\n");
        fprintf(stderr, "      --jul-tcp-port                 JUL application registration TCP port\n");
-       fprintf(stderr, "  -f  --config                       Load daemon configuration file\n");
+       fprintf(stderr, "  -f  --config PATH                  Load daemon configuration file\n");
        fprintf(stderr, "  -l  --load PATH                    Load session configuration\n");
        fprintf(stderr, "      --kmod-probes                  Specify kernel module probes to load\n");
 }
@@ -4198,11 +4251,20 @@ static int set_option(int opt, const char *arg, const char *optname)
                opt_background = 1;
                break;
        case 'g':
+               /*
+                * If the override option is set, the pointer points to a
+                * *non* const thus freeing it even though the variable type is
+                * set to const.
+                */
+               if (tracing_group_name_override) {
+                       free((void *) tracing_group_name);
+               }
                tracing_group_name = strdup(arg);
                if (!tracing_group_name) {
                        perror("strdup");
                        ret = -ENOMEM;
                }
+               tracing_group_name_override = 1;
                break;
        case 'h':
                usage();
@@ -4240,13 +4302,15 @@ static int set_option(int opt, const char *arg, const char *optname)
        case 'v':
                /* Verbose level can increase using multiple -v */
                if (arg) {
+                       /* Value obtained from config file */
                        lttng_opt_verbose = config_parse_value(arg);
                } else {
-                       /* Only 3 level of verbosity (-vvv). */
-                       if (lttng_opt_verbose < 3) {
-                               lttng_opt_verbose += 1;
-                       }
+                       /* -v used on command line */
+                       lttng_opt_verbose++;
                }
+               /* Clamp value to [0, 3] */
+               lttng_opt_verbose = lttng_opt_verbose < 0 ? 0 :
+                       (lttng_opt_verbose <= 3 ? lttng_opt_verbose : 3);
                break;
        case 'Z':
                if (arg) {
@@ -4256,6 +4320,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'u':
+               if (consumerd32_bin_override) {
+                       free((void *) consumerd32_bin);
+               }
                consumerd32_bin = strdup(arg);
                if (!consumerd32_bin) {
                        perror("strdup");
@@ -4264,6 +4331,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd32_bin_override = 1;
                break;
        case 'U':
+               if (consumerd32_libdir_override) {
+                       free((void *) consumerd32_libdir);
+               }
                consumerd32_libdir = strdup(arg);
                if (!consumerd32_libdir) {
                        perror("strdup");
@@ -4272,6 +4342,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd32_libdir_override = 1;
                break;
        case 't':
+               if (consumerd64_bin_override) {
+                       free((void *) consumerd64_bin);
+               }
                consumerd64_bin = strdup(arg);
                if (!consumerd64_bin) {
                        perror("strdup");
@@ -4280,6 +4353,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd64_bin_override = 1;
                break;
        case 'T':
+               if (consumerd64_libdir_override) {
+                       free((void *) consumerd64_libdir);
+               }
                consumerd64_libdir = strdup(arg);
                if (!consumerd64_libdir) {
                        perror("strdup");
@@ -4288,6 +4364,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd64_libdir_override = 1;
                break;
        case 'p':
+               free(opt_pidfile);
                opt_pidfile = strdup(arg);
                if (!opt_pidfile) {
                        perror("strdup");
@@ -4313,6 +4390,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                break;
        }
        case 'l':
+               free(opt_load_session_path);
                opt_load_session_path = strdup(arg);
                if (!opt_load_session_path) {
                        perror("strdup");
@@ -4320,6 +4398,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'P': /* probe modules list */
+               free(kmod_probes_list);
                kmod_probes_list = strdup(arg);
                if (!kmod_probes_list) {
                        perror("strdup");
@@ -4828,6 +4907,24 @@ error:
        return;
 }
 
+/*
+ * Create lockfile using the rundir and return its fd.
+ */
+static int create_lockfile(void)
+{
+       int ret;
+       char lockfile_path[PATH_MAX];
+
+       ret = generate_lock_file_path(lockfile_path, sizeof(lockfile_path));
+       if (ret < 0) {
+               goto error;
+       }
+
+       ret = utils_create_lock_file(lockfile_path);
+error:
+       return ret;
+}
+
 /*
  * Write JUL TCP port using the rundir.
  */
@@ -5033,6 +5130,11 @@ int main(int argc, char **argv)
                }
        }
 
+       lockfile_fd = create_lockfile();
+       if (lockfile_fd < 0) {
+               goto error;
+       }
+
        /* Set consumer initial state */
        kernel_consumerd_state = CONSUMER_STOPPED;
        ust_consumerd_state = CONSUMER_STOPPED;
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