src/bin/lttng/commands/rotate.c

   1 /*
   2  * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27 #include <ctype.h>
  28 #include <assert.h>
  29
  30 #include <common/sessiond-comm/sessiond-comm.h>
  31 #include <common/mi-lttng.h>
  32
  33 #include "../command.h"
  34 #include <lttng/rotation.h>
  35
  36 static char *opt_session_name;
  37 static int opt_no_wait;
  38 static struct mi_writer *writer;
  39
  40 enum {
  41         OPT_HELP = 1,
  42         OPT_LIST_OPTIONS,
  43 };
  44
  45 static struct poptOption long_options[] = {
  46         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  47         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  48         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  49         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  50         {0, 0, 0, 0, 0, 0, 0}
  51 };
  52
  53 static int mi_output_rotate(const char *status, const char *path,
  54                 const char *session_name)
  55 {
  56         int ret;
  57
  58         if (!lttng_opt_mi) {
  59                 ret = 0;
  60                 goto end;
  61         }
  62
  63         ret = mi_lttng_writer_open_element(writer,
  64                         mi_lttng_element_rotation);
  65         if (ret) {
  66                 goto end;
  67         }
  68
  69         ret = mi_lttng_writer_write_element_string(writer,
  70                         mi_lttng_element_session_name, session_name);
  71         if (ret) {
  72                 goto end;
  73         }
  74
  75         ret = mi_lttng_writer_write_element_string(writer,
  76                         mi_lttng_element_rotate_status, status);
  77         if (ret) {
  78                 goto end;
  79         }
  80         if (path) {
  81                 ret = mi_lttng_writer_write_element_string(writer,
  82                                 config_element_path, path);
  83                 if (ret) {
  84                         goto end;
  85                 }
  86         }
  87         /* Close rotation element */
  88         ret = mi_lttng_writer_close_element(writer);
  89         if (ret) {
  90                 goto end;
  91         }
  92
  93 end:
  94         return ret;
  95 }
  96
  97 static int rotate_tracing(char *session_name)
  98 {
  99         int ret;
 100         struct lttng_rotation_immediate_attr *attr = NULL;
 101         struct lttng_rotation_handle *handle = NULL;
 102         enum lttng_rotation_status rotation_status;
 103         enum lttng_rotation_state rotation_state = LTTNG_ROTATION_STATE_ONGOING;
 104
 105         DBG("Rotating the output files of session %s", session_name);
 106
 107         attr = lttng_rotation_immediate_attr_create();
 108         if (!attr) {
 109                 goto error;
 110         }
 111
 112         ret = lttng_rotation_immediate_attr_set_session_name(attr, session_name);
 113         if (ret < 0) {
 114                 ERR("Session name exceeds the maximal allowed length");
 115                 goto error;
 116         }
 117
 118         ret = lttng_rotate_session(attr, &handle);
 119         if (ret < 0) {
 120                 switch (-ret) {
 121                 case LTTNG_ERR_SESSION_NOT_STARTED:
 122                         WARN("Tracing session %s not started yet", session_name);
 123                         break;
 124                 default:
 125                         ERR("%s", lttng_strerror(ret));
 126                         break;
 127                 }
 128                 goto error;
 129         }
 130
 131         if (!opt_no_wait) {
 132                 _MSG("Waiting for rotation to complete");
 133                 ret = fflush(stdout);
 134                 if (ret) {
 135                         PERROR("fflush");
 136                         goto error;
 137                 }
 138
 139                 do {
 140                         rotation_status = lttng_rotation_handle_get_state(handle,
 141                                         &rotation_state);
 142                         if (rotation_status != LTTNG_ROTATION_STATUS_OK) {
 143                                 ERR("Failed to query the state of the rotation");
 144                                 goto error;
 145                         }
 146
 147                         /*
 148                          * Data sleep time before retrying (in usec). Don't
 149                          * sleep if the call returned value indicates
 150                          * availability.
 151                          */
 152                         if (rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
 153                                 ret = usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
 154                                 if (ret) {
 155                                         PERROR("usleep");
 156                                         goto error;
 157                                 }
 158                                 _MSG(".");
 159
 160                                 ret = fflush(stdout);
 161                                 if (ret) {
 162                                         PERROR("fflush");
 163                                         goto error;
 164                                 }
 165                         }
 166                 } while (rotation_state == LTTNG_ROTATION_STATE_ONGOING);
 167                 MSG("");
 168         }
 169
 170         switch (rotation_state) {
 171         case LTTNG_ROTATION_STATE_COMPLETED:
 172         {
 173                 const char *path;
 174
 175                 rotation_status = lttng_rotation_handle_get_completed_archive_location(
 176                                 handle, &path);
 177                 if (rotation_status != LTTNG_ROTATION_STATUS_OK) {
 178                         ERR("Failed to retrieve the rotation's completed chunk archive location");
 179                         goto error;
 180                 }
 181                 MSG("Trace chunk archive for session %s is now readable at %s",
 182                                 session_name, path);
 183                 ret = mi_output_rotate("completed", path, session_name);
 184                 if (ret) {
 185                         goto error;
 186                 }
 187                 ret = CMD_SUCCESS;
 188                 goto end;
 189         }
 190         case LTTNG_ROTATION_STATE_EXPIRED:
 191                 MSG("Session %s rotated, but handle expired", session_name);
 192                 ret = mi_output_rotate("expired", NULL, session_name);
 193                 if (ret) {
 194                         goto error;
 195                 }
 196                 ret = CMD_SUCCESS;
 197                 goto end;
 198         default:
 199                 ERR("Unexpected rotation state received, aborting...");
 200                 goto error;
 201         }
 202
 203 error:
 204         ret = CMD_ERROR;
 205 end:
 206         lttng_rotation_handle_destroy(handle);
 207         lttng_rotation_immediate_attr_destroy(attr);
 208         return ret;
 209 }
 210
 211 /*
 212  *  cmd_rotate
 213  *
 214  *  The 'rotate <options>' first level command
 215  */
 216 int cmd_rotate(int argc, const char **argv)
 217 {
 218         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 219         int popt_ret;
 220         static poptContext pc;
 221         char *session_name = NULL;
 222         bool free_session_name = false;
 223
 224         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 225         popt_ret = poptReadDefaultConfig(pc, 0);
 226         if (popt_ret) {
 227                 ret = CMD_ERROR;
 228                 ERR("poptReadDefaultConfig");
 229                 goto end;
 230         }
 231
 232         while ((opt = poptGetNextOpt(pc)) != -1) {
 233                 switch (opt) {
 234                 case OPT_HELP:
 235                         SHOW_HELP();
 236                         goto end;
 237                 case OPT_LIST_OPTIONS:
 238                         list_cmd_options(stdout, long_options);
 239                         goto end;
 240                 default:
 241                         ret = CMD_UNDEFINED;
 242                         goto end;
 243                 }
 244         }
 245
 246         opt_session_name = (char*) poptGetArg(pc);
 247
 248         if (!opt_session_name) {
 249                 session_name = get_session_name();
 250                 if (!session_name) {
 251                         goto end;
 252                 }
 253                 free_session_name = true;
 254         } else {
 255                 session_name = opt_session_name;
 256         }
 257
 258         /* Mi check */
 259         if (lttng_opt_mi) {
 260                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 261                 if (!writer) {
 262                         ret = -LTTNG_ERR_NOMEM;
 263                         goto end;
 264                 }
 265
 266                 /* Open rotate command */
 267                 ret = mi_lttng_writer_command_open(writer,
 268                                 mi_lttng_element_command_rotate);
 269                 if (ret) {
 270                         ret = CMD_ERROR;
 271                         goto end;
 272                 }
 273
 274                 /* Open output element */
 275                 ret = mi_lttng_writer_open_element(writer,
 276                                 mi_lttng_element_command_output);
 277                 if (ret) {
 278                         goto end;
 279                 }
 280
 281                 /* Open rotations element */
 282                 ret = mi_lttng_writer_open_element(writer,
 283                                 mi_lttng_element_rotations);
 284                 if (ret) {
 285                         goto end;
 286                 }
 287
 288         }
 289
 290         command_ret = rotate_tracing(session_name);
 291         if (command_ret) {
 292                 success = 0;
 293         }
 294
 295         /* Mi closing */
 296         if (lttng_opt_mi) {
 297                 /* Close  rotations element */
 298                 ret = mi_lttng_writer_close_element(writer);
 299                 if (ret) {
 300                         goto end;
 301                 }
 302                 /* Close  output element */
 303                 ret = mi_lttng_writer_close_element(writer);
 304                 if (ret) {
 305                         goto end;
 306                 }
 307                 /* Success ? */
 308                 ret = mi_lttng_writer_write_element_bool(writer,
 309                                 mi_lttng_element_command_success, success);
 310                 if (ret) {
 311                         ret = CMD_ERROR;
 312                         goto end;
 313                 }
 314
 315                 /* Command element close */
 316                 ret = mi_lttng_writer_command_close(writer);
 317                 if (ret) {
 318                         ret = CMD_ERROR;
 319                         goto end;
 320                 }
 321         }
 322
 323 end:
 324         /* Mi clean-up */
 325         if (writer && mi_lttng_writer_destroy(writer)) {
 326                 /* Preserve original error code */
 327                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 328         }
 329
 330         /* Overwrite ret if an error occurred with start_tracing */
 331         ret = command_ret ? command_ret : ret;
 332         poptFreeContext(pc);
 333         if (free_session_name) {
 334                 free(session_name);
 335         }
 336         return ret;
 337 }