| 1 | /* lttd |
| 2 | * |
| 3 | * Linux Trace Toolkit Daemon |
| 4 | * |
| 5 | * This is a simple daemon that reads a few relay+debugfs channels and save |
| 6 | * them in a trace. |
| 7 | * |
| 8 | * |
| 9 | * Copyright 2005 - |
| 10 | * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
| 11 | */ |
| 12 | |
| 13 | #ifdef HAVE_CONFIG_H |
| 14 | #include <config.h> |
| 15 | #endif |
| 16 | |
| 17 | #define _REENTRANT |
| 18 | #define _GNU_SOURCE |
| 19 | #include <features.h> |
| 20 | #include <stdio.h> |
| 21 | #include <unistd.h> |
| 22 | #include <errno.h> |
| 23 | #include <sys/types.h> |
| 24 | #include <sys/stat.h> |
| 25 | #include <stdlib.h> |
| 26 | #include <dirent.h> |
| 27 | #include <string.h> |
| 28 | #include <fcntl.h> |
| 29 | #include <sys/poll.h> |
| 30 | #include <sys/mman.h> |
| 31 | #include <signal.h> |
| 32 | #include <pthread.h> |
| 33 | #include <sys/syscall.h> |
| 34 | #include <unistd.h> |
| 35 | #include <asm/ioctls.h> |
| 36 | |
| 37 | #include <linux/version.h> |
| 38 | |
| 39 | /* Relayfs IOCTL */ |
| 40 | #include <asm/ioctl.h> |
| 41 | #include <asm/types.h> |
| 42 | |
| 43 | /* Get the next sub buffer that can be read. */ |
| 44 | #define RELAY_GET_SUBBUF _IOR(0xF5, 0x00,__u32) |
| 45 | /* Release the oldest reserved (by "get") sub buffer. */ |
| 46 | #define RELAY_PUT_SUBBUF _IOW(0xF5, 0x01,__u32) |
| 47 | /* returns the number of sub buffers in the per cpu channel. */ |
| 48 | #define RELAY_GET_N_SUBBUFS _IOR(0xF5, 0x02,__u32) |
| 49 | /* returns the size of the sub buffers. */ |
| 50 | #define RELAY_GET_SUBBUF_SIZE _IOR(0xF5, 0x03,__u32) |
| 51 | |
| 52 | #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14) |
| 53 | #include <linux/inotify.h> |
| 54 | /* From the inotify-tools 2.6 package */ |
| 55 | static inline int inotify_init (void) |
| 56 | { |
| 57 | return syscall (__NR_inotify_init); |
| 58 | } |
| 59 | |
| 60 | static inline int inotify_add_watch (int fd, const char *name, __u32 mask) |
| 61 | { |
| 62 | return syscall (__NR_inotify_add_watch, fd, name, mask); |
| 63 | } |
| 64 | |
| 65 | static inline int inotify_rm_watch (int fd, __u32 wd) |
| 66 | { |
| 67 | return syscall (__NR_inotify_rm_watch, fd, wd); |
| 68 | } |
| 69 | #define HAS_INOTIFY |
| 70 | #else |
| 71 | static inline int inotify_init (void) |
| 72 | { |
| 73 | return -1; |
| 74 | } |
| 75 | |
| 76 | static inline int inotify_add_watch (int fd, const char *name, __u32 mask) |
| 77 | { |
| 78 | return 0; |
| 79 | } |
| 80 | |
| 81 | static inline int inotify_rm_watch (int fd, __u32 wd) |
| 82 | { |
| 83 | return 0; |
| 84 | } |
| 85 | #undef HAS_INOTIFY |
| 86 | #endif |
| 87 | |
| 88 | enum { |
| 89 | GET_SUBBUF, |
| 90 | PUT_SUBBUF, |
| 91 | GET_N_BUBBUFS, |
| 92 | GET_SUBBUF_SIZE |
| 93 | }; |
| 94 | |
| 95 | struct fd_pair { |
| 96 | int channel; |
| 97 | int trace; |
| 98 | unsigned int n_subbufs; |
| 99 | unsigned int subbuf_size; |
| 100 | void *mmap; |
| 101 | pthread_mutex_t mutex; |
| 102 | }; |
| 103 | |
| 104 | struct channel_trace_fd { |
| 105 | struct fd_pair *pair; |
| 106 | int num_pairs; |
| 107 | }; |
| 108 | |
| 109 | struct inotify_watch { |
| 110 | int wd; |
| 111 | char path_channel[PATH_MAX]; |
| 112 | char path_trace[PATH_MAX]; |
| 113 | }; |
| 114 | |
| 115 | struct inotify_watch_array { |
| 116 | struct inotify_watch *elem; |
| 117 | int num; |
| 118 | }; |
| 119 | |
| 120 | static char *trace_name = NULL; |
| 121 | static char *channel_name = NULL; |
| 122 | static int daemon_mode = 0; |
| 123 | static int append_mode = 0; |
| 124 | static unsigned long num_threads = 1; |
| 125 | volatile static int quit_program = 0; /* For signal handler */ |
| 126 | static int dump_flight_only = 0; |
| 127 | static int dump_normal_only = 0; |
| 128 | |
| 129 | /* Args : |
| 130 | * |
| 131 | * -t directory Directory name of the trace to write to. Will be created. |
| 132 | * -c directory Root directory of the debugfs trace channels. |
| 133 | * -d Run in background (daemon). |
| 134 | * -a Trace append mode. |
| 135 | * -s Send SIGUSR1 to parent when ready for IO. |
| 136 | */ |
| 137 | void show_arguments(void) |
| 138 | { |
| 139 | printf("Please use the following arguments :\n"); |
| 140 | printf("\n"); |
| 141 | printf("-t directory Directory name of the trace to write to.\n" |
| 142 | " It will be created.\n"); |
| 143 | printf("-c directory Root directory of the debugfs trace channels.\n"); |
| 144 | printf("-d Run in background (daemon).\n"); |
| 145 | printf("-a Append to an possibly existing trace.\n"); |
| 146 | printf("-N Number of threads to start.\n"); |
| 147 | printf("-f Dump only flight recorder channels.\n"); |
| 148 | printf("-n Dump only normal channels.\n"); |
| 149 | printf("\n"); |
| 150 | } |
| 151 | |
| 152 | |
| 153 | /* parse_arguments |
| 154 | * |
| 155 | * Parses the command line arguments. |
| 156 | * |
| 157 | * Returns 1 if the arguments were correct, but doesn't ask for program |
| 158 | * continuation. Returns -1 if the arguments are incorrect, or 0 if OK. |
| 159 | */ |
| 160 | int parse_arguments(int argc, char **argv) |
| 161 | { |
| 162 | int ret = 0; |
| 163 | int argn = 1; |
| 164 | |
| 165 | if(argc == 2) { |
| 166 | if(strcmp(argv[1], "-h") == 0) { |
| 167 | return 1; |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | while(argn < argc) { |
| 172 | |
| 173 | switch(argv[argn][0]) { |
| 174 | case '-': |
| 175 | switch(argv[argn][1]) { |
| 176 | case 't': |
| 177 | if(argn+1 < argc) { |
| 178 | trace_name = argv[argn+1]; |
| 179 | argn++; |
| 180 | } |
| 181 | break; |
| 182 | case 'c': |
| 183 | if(argn+1 < argc) { |
| 184 | channel_name = argv[argn+1]; |
| 185 | argn++; |
| 186 | } |
| 187 | break; |
| 188 | case 'd': |
| 189 | daemon_mode = 1; |
| 190 | break; |
| 191 | case 'a': |
| 192 | append_mode = 1; |
| 193 | break; |
| 194 | case 'N': |
| 195 | if(argn+1 < argc) { |
| 196 | num_threads = strtoul(argv[argn+1], NULL, 0); |
| 197 | argn++; |
| 198 | } |
| 199 | break; |
| 200 | case 'f': |
| 201 | dump_flight_only = 1; |
| 202 | break; |
| 203 | case 'n': |
| 204 | dump_normal_only = 1; |
| 205 | break; |
| 206 | default: |
| 207 | printf("Invalid argument '%s'.\n", argv[argn]); |
| 208 | printf("\n"); |
| 209 | ret = -1; |
| 210 | } |
| 211 | break; |
| 212 | default: |
| 213 | printf("Invalid argument '%s'.\n", argv[argn]); |
| 214 | printf("\n"); |
| 215 | ret = -1; |
| 216 | } |
| 217 | argn++; |
| 218 | } |
| 219 | |
| 220 | if(trace_name == NULL) { |
| 221 | printf("Please specify a trace name.\n"); |
| 222 | printf("\n"); |
| 223 | ret = -1; |
| 224 | } |
| 225 | |
| 226 | if(channel_name == NULL) { |
| 227 | printf("Please specify a channel name.\n"); |
| 228 | printf("\n"); |
| 229 | ret = -1; |
| 230 | } |
| 231 | |
| 232 | return ret; |
| 233 | } |
| 234 | |
| 235 | void show_info(void) |
| 236 | { |
| 237 | printf("Linux Trace Toolkit Trace Daemon " VERSION "\n"); |
| 238 | printf("\n"); |
| 239 | printf("Reading from debugfs directory : %s\n", channel_name); |
| 240 | printf("Writing to trace directory : %s\n", trace_name); |
| 241 | printf("\n"); |
| 242 | } |
| 243 | |
| 244 | |
| 245 | /* signal handling */ |
| 246 | |
| 247 | static void handler(int signo) |
| 248 | { |
| 249 | printf("Signal %d received : exiting cleanly\n", signo); |
| 250 | quit_program = 1; |
| 251 | } |
| 252 | |
| 253 | |
| 254 | int open_buffer_file(char *filename, char *path_channel, char *path_trace, |
| 255 | struct channel_trace_fd *fd_pairs) |
| 256 | { |
| 257 | int open_ret = 0; |
| 258 | int ret = 0; |
| 259 | struct stat stat_buf; |
| 260 | |
| 261 | if(strncmp(filename, "flight-", sizeof("flight-")-1) != 0) { |
| 262 | if(dump_flight_only) { |
| 263 | printf("Skipping normal channel %s\n", path_channel); |
| 264 | return 0; |
| 265 | } |
| 266 | } else { |
| 267 | if(dump_normal_only) { |
| 268 | printf("Skipping flight channel %s\n", path_channel); |
| 269 | return 0; |
| 270 | } |
| 271 | } |
| 272 | printf("Opening file.\n"); |
| 273 | |
| 274 | fd_pairs->pair = realloc(fd_pairs->pair, |
| 275 | ++fd_pairs->num_pairs * sizeof(struct fd_pair)); |
| 276 | |
| 277 | /* Open the channel in read mode */ |
| 278 | fd_pairs->pair[fd_pairs->num_pairs-1].channel = |
| 279 | open(path_channel, O_RDONLY | O_NONBLOCK); |
| 280 | if(fd_pairs->pair[fd_pairs->num_pairs-1].channel == -1) { |
| 281 | perror(path_channel); |
| 282 | fd_pairs->num_pairs--; |
| 283 | return 0; /* continue */ |
| 284 | } |
| 285 | /* Open the trace in write mode, only append if append_mode */ |
| 286 | ret = stat(path_trace, &stat_buf); |
| 287 | if(ret == 0) { |
| 288 | if(append_mode) { |
| 289 | printf("Appending to file %s as requested\n", path_trace); |
| 290 | |
| 291 | fd_pairs->pair[fd_pairs->num_pairs-1].trace = |
| 292 | open(path_trace, O_WRONLY|O_APPEND, |
| 293 | S_IRWXU|S_IRWXG|S_IRWXO); |
| 294 | |
| 295 | if(fd_pairs->pair[fd_pairs->num_pairs-1].trace == -1) { |
| 296 | perror(path_trace); |
| 297 | } |
| 298 | } else { |
| 299 | printf("File %s exists, cannot open. Try append mode.\n", path_trace); |
| 300 | open_ret = -1; |
| 301 | goto end; |
| 302 | } |
| 303 | } else { |
| 304 | if(errno == ENOENT) { |
| 305 | fd_pairs->pair[fd_pairs->num_pairs-1].trace = |
| 306 | open(path_trace, O_WRONLY|O_CREAT|O_EXCL, |
| 307 | S_IRWXU|S_IRWXG|S_IRWXO); |
| 308 | if(fd_pairs->pair[fd_pairs->num_pairs-1].trace == -1) { |
| 309 | perror(path_trace); |
| 310 | } |
| 311 | } |
| 312 | } |
| 313 | end: |
| 314 | return open_ret; |
| 315 | } |
| 316 | |
| 317 | int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name, |
| 318 | struct channel_trace_fd *fd_pairs, int *inotify_fd, |
| 319 | struct inotify_watch_array *iwatch_array) |
| 320 | { |
| 321 | DIR *channel_dir = opendir(subchannel_name); |
| 322 | struct dirent *entry; |
| 323 | struct stat stat_buf; |
| 324 | int ret; |
| 325 | char path_channel[PATH_MAX]; |
| 326 | int path_channel_len; |
| 327 | char *path_channel_ptr; |
| 328 | char path_trace[PATH_MAX]; |
| 329 | int path_trace_len; |
| 330 | char *path_trace_ptr; |
| 331 | int open_ret = 0; |
| 332 | |
| 333 | if(channel_dir == NULL) { |
| 334 | perror(subchannel_name); |
| 335 | open_ret = ENOENT; |
| 336 | goto end; |
| 337 | } |
| 338 | |
| 339 | printf("Creating trace subdirectory %s\n", subtrace_name); |
| 340 | ret = mkdir(subtrace_name, S_IRWXU|S_IRWXG|S_IRWXO); |
| 341 | if(ret == -1) { |
| 342 | if(errno != EEXIST) { |
| 343 | perror(subtrace_name); |
| 344 | open_ret = -1; |
| 345 | goto end; |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | strncpy(path_channel, subchannel_name, PATH_MAX-1); |
| 350 | path_channel_len = strlen(path_channel); |
| 351 | path_channel[path_channel_len] = '/'; |
| 352 | path_channel_len++; |
| 353 | path_channel_ptr = path_channel + path_channel_len; |
| 354 | |
| 355 | strncpy(path_trace, subtrace_name, PATH_MAX-1); |
| 356 | path_trace_len = strlen(path_trace); |
| 357 | path_trace[path_trace_len] = '/'; |
| 358 | path_trace_len++; |
| 359 | path_trace_ptr = path_trace + path_trace_len; |
| 360 | |
| 361 | #ifdef HAS_INOTIFY |
| 362 | iwatch_array->elem = realloc(iwatch_array->elem, |
| 363 | ++iwatch_array->num * sizeof(struct inotify_watch)); |
| 364 | |
| 365 | printf("Adding inotify for channel %s\n", path_channel); |
| 366 | iwatch_array->elem[iwatch_array->num-1].wd = inotify_add_watch(*inotify_fd, path_channel, IN_CREATE); |
| 367 | strcpy(iwatch_array->elem[iwatch_array->num-1].path_channel, path_channel); |
| 368 | strcpy(iwatch_array->elem[iwatch_array->num-1].path_trace, path_trace); |
| 369 | printf("Added inotify for channel %s, wd %u\n", iwatch_array->elem[iwatch_array->num-1].path_channel, |
| 370 | iwatch_array->elem[iwatch_array->num-1].wd); |
| 371 | #endif |
| 372 | |
| 373 | while((entry = readdir(channel_dir)) != NULL) { |
| 374 | |
| 375 | if(entry->d_name[0] == '.') continue; |
| 376 | |
| 377 | strncpy(path_channel_ptr, entry->d_name, PATH_MAX - path_channel_len); |
| 378 | strncpy(path_trace_ptr, entry->d_name, PATH_MAX - path_trace_len); |
| 379 | |
| 380 | ret = stat(path_channel, &stat_buf); |
| 381 | if(ret == -1) { |
| 382 | perror(path_channel); |
| 383 | continue; |
| 384 | } |
| 385 | |
| 386 | printf("Channel file : %s\n", path_channel); |
| 387 | |
| 388 | if(S_ISDIR(stat_buf.st_mode)) { |
| 389 | |
| 390 | printf("Entering channel subdirectory...\n"); |
| 391 | ret = open_channel_trace_pairs(path_channel, path_trace, fd_pairs, |
| 392 | inotify_fd, iwatch_array); |
| 393 | if(ret < 0) continue; |
| 394 | } else if(S_ISREG(stat_buf.st_mode)) { |
| 395 | open_ret = open_buffer_file(entry->d_name, path_channel, path_trace, |
| 396 | fd_pairs); |
| 397 | if(open_ret) |
| 398 | goto end; |
| 399 | } |
| 400 | } |
| 401 | |
| 402 | end: |
| 403 | closedir(channel_dir); |
| 404 | |
| 405 | return open_ret; |
| 406 | } |
| 407 | |
| 408 | |
| 409 | int read_subbuffer(struct fd_pair *pair) |
| 410 | { |
| 411 | unsigned int consumed_old; |
| 412 | int err, ret=0; |
| 413 | |
| 414 | |
| 415 | err = ioctl(pair->channel, RELAY_GET_SUBBUF, |
| 416 | &consumed_old); |
| 417 | printf("cookie : %u\n", consumed_old); |
| 418 | if(err != 0) { |
| 419 | ret = errno; |
| 420 | perror("Reserving sub buffer failed (everything is normal, it is due to concurrency)"); |
| 421 | goto get_error; |
| 422 | } |
| 423 | |
| 424 | err = TEMP_FAILURE_RETRY(write(pair->trace, |
| 425 | pair->mmap |
| 426 | + (consumed_old & ((pair->n_subbufs * pair->subbuf_size)-1)), |
| 427 | pair->subbuf_size)); |
| 428 | |
| 429 | if(err < 0) { |
| 430 | ret = errno; |
| 431 | perror("Error in writing to file"); |
| 432 | goto write_error; |
| 433 | } |
| 434 | #if 0 |
| 435 | err = fsync(pair->trace); |
| 436 | if(err < 0) { |
| 437 | ret = errno; |
| 438 | perror("Error in writing to file"); |
| 439 | goto write_error; |
| 440 | } |
| 441 | #endif //0 |
| 442 | write_error: |
| 443 | err = ioctl(pair->channel, RELAY_PUT_SUBBUF, &consumed_old); |
| 444 | if(err != 0) { |
| 445 | ret = errno; |
| 446 | if(errno == EFAULT) { |
| 447 | perror("Error in unreserving sub buffer\n"); |
| 448 | } else if(errno == EIO) { |
| 449 | perror("Reader has been pushed by the writer, last subbuffer corrupted."); |
| 450 | /* FIXME : we may delete the last written buffer if we wish. */ |
| 451 | } |
| 452 | goto get_error; |
| 453 | } |
| 454 | |
| 455 | get_error: |
| 456 | return ret; |
| 457 | } |
| 458 | |
| 459 | |
| 460 | |
| 461 | int map_channels(struct channel_trace_fd *fd_pairs, |
| 462 | int idx_begin, int idx_end) |
| 463 | { |
| 464 | int i,j; |
| 465 | int ret=0; |
| 466 | |
| 467 | if(fd_pairs->num_pairs <= 0) { |
| 468 | printf("No channel to read\n"); |
| 469 | goto end; |
| 470 | } |
| 471 | |
| 472 | /* Get the subbuf sizes and number */ |
| 473 | |
| 474 | for(i=idx_begin;i<idx_end;i++) { |
| 475 | struct fd_pair *pair = &fd_pairs->pair[i]; |
| 476 | |
| 477 | ret = ioctl(pair->channel, RELAY_GET_N_SUBBUFS, |
| 478 | &pair->n_subbufs); |
| 479 | if(ret != 0) { |
| 480 | perror("Error in getting the number of subbuffers"); |
| 481 | goto end; |
| 482 | } |
| 483 | ret = ioctl(pair->channel, RELAY_GET_SUBBUF_SIZE, |
| 484 | &pair->subbuf_size); |
| 485 | if(ret != 0) { |
| 486 | perror("Error in getting the size of the subbuffers"); |
| 487 | goto end; |
| 488 | } |
| 489 | ret = pthread_mutex_init(&pair->mutex, NULL); /* Fast mutex */ |
| 490 | if(ret != 0) { |
| 491 | perror("Error in mutex init"); |
| 492 | goto end; |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | /* Mmap each FD */ |
| 497 | for(i=idx_begin;i<idx_end;i++) { |
| 498 | struct fd_pair *pair = &fd_pairs->pair[i]; |
| 499 | |
| 500 | pair->mmap = mmap(0, pair->subbuf_size * pair->n_subbufs, PROT_READ, |
| 501 | MAP_SHARED, pair->channel, 0); |
| 502 | if(pair->mmap == MAP_FAILED) { |
| 503 | perror("Mmap error"); |
| 504 | goto munmap; |
| 505 | } |
| 506 | } |
| 507 | |
| 508 | goto end; /* success */ |
| 509 | |
| 510 | /* Error handling */ |
| 511 | /* munmap only the successfully mmapped indexes */ |
| 512 | munmap: |
| 513 | /* Munmap each FD */ |
| 514 | for(j=idx_begin;j<i;j++) { |
| 515 | struct fd_pair *pair = &fd_pairs->pair[j]; |
| 516 | int err_ret; |
| 517 | |
| 518 | err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs); |
| 519 | if(err_ret != 0) { |
| 520 | perror("Error in munmap"); |
| 521 | } |
| 522 | ret |= err_ret; |
| 523 | } |
| 524 | |
| 525 | end: |
| 526 | return ret; |
| 527 | |
| 528 | |
| 529 | } |
| 530 | |
| 531 | |
| 532 | int unmap_channels(struct channel_trace_fd *fd_pairs) |
| 533 | { |
| 534 | int j; |
| 535 | int ret=0; |
| 536 | |
| 537 | /* Munmap each FD */ |
| 538 | for(j=0;j<fd_pairs->num_pairs;j++) { |
| 539 | struct fd_pair *pair = &fd_pairs->pair[j]; |
| 540 | int err_ret; |
| 541 | |
| 542 | err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs); |
| 543 | if(err_ret != 0) { |
| 544 | perror("Error in munmap"); |
| 545 | } |
| 546 | ret |= err_ret; |
| 547 | err_ret = pthread_mutex_destroy(&pair->mutex); |
| 548 | if(err_ret != 0) { |
| 549 | perror("Error in mutex destroy"); |
| 550 | } |
| 551 | ret |= err_ret; |
| 552 | } |
| 553 | |
| 554 | return ret; |
| 555 | } |
| 556 | |
| 557 | #ifdef HAS_INOTIFY |
| 558 | /* Inotify event arrived. |
| 559 | * |
| 560 | * Only support add file for now. |
| 561 | */ |
| 562 | |
| 563 | int read_inotify(int inotify_fd, |
| 564 | struct channel_trace_fd *fd_pairs, |
| 565 | struct inotify_watch_array *iwatch_array) |
| 566 | { |
| 567 | char buf[sizeof(struct inotify_event) + PATH_MAX]; |
| 568 | char path_channel[PATH_MAX]; |
| 569 | char path_trace[PATH_MAX]; |
| 570 | ssize_t len; |
| 571 | struct inotify_event *ievent; |
| 572 | size_t offset; |
| 573 | unsigned int i; |
| 574 | int ret; |
| 575 | int old_num; |
| 576 | |
| 577 | offset = 0; |
| 578 | len = read(inotify_fd, buf, sizeof(struct inotify_event) + PATH_MAX); |
| 579 | if(len < 0) { |
| 580 | printf("Error in read from inotify FD %s.\n", strerror(len)); |
| 581 | return -1; |
| 582 | } |
| 583 | while(offset < len) { |
| 584 | ievent = (struct inotify_event *)&(buf[offset]); |
| 585 | for(i=0; i<iwatch_array->num; i++) { |
| 586 | if(iwatch_array->elem[i].wd == ievent->wd && |
| 587 | ievent->mask == IN_CREATE) { |
| 588 | printf("inotify wd %u event mask : %u for %s%s\n", |
| 589 | ievent->wd, ievent->mask, |
| 590 | iwatch_array->elem[i].path_channel, ievent->name); |
| 591 | old_num = fd_pairs->num_pairs; |
| 592 | strcpy(path_channel, iwatch_array->elem[i].path_channel); |
| 593 | strcat(path_channel, ievent->name); |
| 594 | strcpy(path_trace, iwatch_array->elem[i].path_trace); |
| 595 | strcat(path_trace, ievent->name); |
| 596 | if(ret = open_buffer_file(ievent->name, path_channel, |
| 597 | path_trace, fd_pairs)) { |
| 598 | printf("Error opening buffer file\n"); |
| 599 | return -1; |
| 600 | } |
| 601 | if(ret = map_channels(fd_pairs, old_num, fd_pairs->num_pairs)) { |
| 602 | printf("Error mapping channel\n"); |
| 603 | return -1; |
| 604 | } |
| 605 | |
| 606 | } |
| 607 | } |
| 608 | offset += sizeof(*ievent) + ievent->len; |
| 609 | } |
| 610 | } |
| 611 | #endif //HAS_INOTIFY |
| 612 | |
| 613 | /* read_channels |
| 614 | * |
| 615 | * Thread worker. |
| 616 | * |
| 617 | * Read the debugfs channels and write them in the paired tracefiles. |
| 618 | * |
| 619 | * @fd_pairs : paired channels and trace files. |
| 620 | * |
| 621 | * returns 0 on success, -1 on error. |
| 622 | * |
| 623 | * Note that the high priority polled channels are consumed first. We then poll |
| 624 | * again to see if these channels are still in priority. Only when no |
| 625 | * high priority channel is left, we start reading low priority channels. |
| 626 | * |
| 627 | * Note that a channel is considered high priority when the buffer is almost |
| 628 | * full. |
| 629 | */ |
| 630 | |
| 631 | int read_channels(unsigned int thread_num, struct channel_trace_fd *fd_pairs, |
| 632 | int inotify_fd, struct inotify_watch_array *iwatch_array) |
| 633 | { |
| 634 | struct pollfd *pollfd = NULL; |
| 635 | int i,j; |
| 636 | int num_rdy, num_hup; |
| 637 | int high_prio; |
| 638 | int ret = 0; |
| 639 | int inotify_fds; |
| 640 | unsigned int old_num; |
| 641 | |
| 642 | #ifdef HAS_INOTIFY |
| 643 | inotify_fds = 1; |
| 644 | #else |
| 645 | inotify_fds = 0; |
| 646 | #endif |
| 647 | |
| 648 | /* Start polling the FD. Keep one fd for inotify */ |
| 649 | pollfd = malloc((inotify_fds + fd_pairs->num_pairs) * sizeof(struct pollfd)); |
| 650 | |
| 651 | #ifdef HAS_INOTIFY |
| 652 | pollfd[0].fd = inotify_fd; |
| 653 | pollfd[0].events = POLLIN|POLLPRI; |
| 654 | #endif |
| 655 | |
| 656 | for(i=0;i<fd_pairs->num_pairs;i++) { |
| 657 | pollfd[inotify_fds+i].fd = fd_pairs->pair[i].channel; |
| 658 | pollfd[inotify_fds+i].events = POLLIN|POLLPRI; |
| 659 | } |
| 660 | |
| 661 | while(1) { |
| 662 | high_prio = 0; |
| 663 | num_hup = 0; |
| 664 | #ifdef DEBUG |
| 665 | printf("Press a key for next poll...\n"); |
| 666 | char buf[1]; |
| 667 | read(STDIN_FILENO, &buf, 1); |
| 668 | printf("Next poll (polling %d fd) :\n", 1+fd_pairs->num_pairs); |
| 669 | #endif //DEBUG |
| 670 | |
| 671 | /* Have we received a signal ? */ |
| 672 | if(quit_program) break; |
| 673 | |
| 674 | num_rdy = poll(pollfd, inotify_fds+fd_pairs->num_pairs, -1); |
| 675 | if(num_rdy == -1) { |
| 676 | perror("Poll error"); |
| 677 | goto free_fd; |
| 678 | } |
| 679 | |
| 680 | printf("Data received\n"); |
| 681 | #ifdef HAS_INOTIFY |
| 682 | switch(pollfd[0].revents) { |
| 683 | case POLLERR: |
| 684 | printf("Error returned in polling inotify fd %d.\n", pollfd[0].fd); |
| 685 | break; |
| 686 | case POLLHUP: |
| 687 | printf("Polling inotify fd %d tells it has hung up.\n", pollfd[0].fd); |
| 688 | break; |
| 689 | case POLLNVAL: |
| 690 | printf("Polling inotify fd %d tells fd is not open.\n", pollfd[0].fd); |
| 691 | break; |
| 692 | case POLLPRI: |
| 693 | case POLLIN: |
| 694 | printf("Polling inotify fd %d : data ready.\n", pollfd[0].fd); |
| 695 | old_num = fd_pairs->num_pairs; |
| 696 | read_inotify(inotify_fd, fd_pairs, iwatch_array); |
| 697 | pollfd = realloc(pollfd, |
| 698 | (inotify_fds + fd_pairs->num_pairs) * sizeof(struct pollfd)); |
| 699 | for(i=old_num;i<fd_pairs->num_pairs;i++) { |
| 700 | pollfd[inotify_fds+i].fd = fd_pairs->pair[i].channel; |
| 701 | pollfd[inotify_fds+i].events = POLLIN|POLLPRI; |
| 702 | } |
| 703 | break; |
| 704 | } |
| 705 | #endif |
| 706 | |
| 707 | for(i=inotify_fds;i<inotify_fds+fd_pairs->num_pairs;i++) { |
| 708 | switch(pollfd[i].revents) { |
| 709 | case POLLERR: |
| 710 | printf("Error returned in polling fd %d.\n", pollfd[i].fd); |
| 711 | num_hup++; |
| 712 | break; |
| 713 | case POLLHUP: |
| 714 | printf("Polling fd %d tells it has hung up.\n", pollfd[i].fd); |
| 715 | num_hup++; |
| 716 | break; |
| 717 | case POLLNVAL: |
| 718 | printf("Polling fd %d tells fd is not open.\n", pollfd[i].fd); |
| 719 | num_hup++; |
| 720 | break; |
| 721 | case POLLPRI: |
| 722 | if(pthread_mutex_trylock(&fd_pairs->pair[i-inotify_fds].mutex) == 0) { |
| 723 | printf("Urgent read on fd %d\n", pollfd[i].fd); |
| 724 | /* Take care of high priority channels first. */ |
| 725 | high_prio = 1; |
| 726 | /* it's ok to have an unavailable subbuffer */ |
| 727 | ret = read_subbuffer(&fd_pairs->pair[i-inotify_fds]); |
| 728 | if(ret == EAGAIN) ret = 0; |
| 729 | |
| 730 | ret = pthread_mutex_unlock(&fd_pairs->pair[i-inotify_fds].mutex); |
| 731 | if(ret) |
| 732 | printf("Error in mutex unlock : %s\n", strerror(ret)); |
| 733 | } |
| 734 | break; |
| 735 | } |
| 736 | } |
| 737 | /* If every buffer FD has hung up, we end the read loop here */ |
| 738 | if(num_hup == fd_pairs->num_pairs) break; |
| 739 | |
| 740 | if(!high_prio) { |
| 741 | for(i=inotify_fds;i<inotify_fds+fd_pairs->num_pairs;i++) { |
| 742 | switch(pollfd[i].revents) { |
| 743 | case POLLIN: |
| 744 | if(pthread_mutex_trylock(&fd_pairs->pair[i-inotify_fds].mutex) == 0) { |
| 745 | /* Take care of low priority channels. */ |
| 746 | printf("Normal read on fd %d\n", pollfd[i].fd); |
| 747 | /* it's ok to have an unavailable subbuffer */ |
| 748 | ret = read_subbuffer(&fd_pairs->pair[i-inotify_fds]); |
| 749 | if(ret == EAGAIN) ret = 0; |
| 750 | |
| 751 | ret = pthread_mutex_unlock(&fd_pairs->pair[i-inotify_fds].mutex); |
| 752 | if(ret) |
| 753 | printf("Error in mutex unlock : %s\n", strerror(ret)); |
| 754 | } |
| 755 | break; |
| 756 | } |
| 757 | } |
| 758 | } |
| 759 | |
| 760 | } |
| 761 | |
| 762 | free_fd: |
| 763 | free(pollfd); |
| 764 | |
| 765 | end: |
| 766 | return ret; |
| 767 | } |
| 768 | |
| 769 | |
| 770 | void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs, int inotify_fd, |
| 771 | struct inotify_watch_array *iwatch_array) |
| 772 | { |
| 773 | int i; |
| 774 | int ret; |
| 775 | |
| 776 | for(i=0;i<fd_pairs->num_pairs;i++) { |
| 777 | ret = close(fd_pairs->pair[i].channel); |
| 778 | if(ret == -1) perror("Close error on channel"); |
| 779 | ret = close(fd_pairs->pair[i].trace); |
| 780 | if(ret == -1) perror("Close error on trace"); |
| 781 | } |
| 782 | free(fd_pairs->pair); |
| 783 | free(iwatch_array->elem); |
| 784 | } |
| 785 | |
| 786 | /* Thread worker */ |
| 787 | void * thread_main(void *arg) |
| 788 | { |
| 789 | struct channel_trace_fd fd_pairs = { NULL, 0 }; |
| 790 | int inotify_fd = -1; |
| 791 | struct inotify_watch_array inotify_watch_array = { NULL, 0 }; |
| 792 | int ret = 0; |
| 793 | unsigned int thread_num = (unsigned int)arg; |
| 794 | |
| 795 | inotify_fd = inotify_init(); |
| 796 | |
| 797 | if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs, |
| 798 | &inotify_fd, &inotify_watch_array)) |
| 799 | goto close_channel; |
| 800 | |
| 801 | if(ret = map_channels(&fd_pairs, 0, fd_pairs.num_pairs)) |
| 802 | goto close_channel; |
| 803 | |
| 804 | ret = read_channels(thread_num, &fd_pairs, inotify_fd, &inotify_watch_array); |
| 805 | |
| 806 | ret |= unmap_channels(&fd_pairs); |
| 807 | |
| 808 | close_channel: |
| 809 | close_channel_trace_pairs(&fd_pairs, inotify_fd, &inotify_watch_array); |
| 810 | if(inotify_fd >= 0) |
| 811 | close(inotify_fd); |
| 812 | |
| 813 | return (void*)ret; |
| 814 | } |
| 815 | |
| 816 | |
| 817 | int main(int argc, char ** argv) |
| 818 | { |
| 819 | int ret = 0; |
| 820 | struct sigaction act; |
| 821 | pthread_t *tids; |
| 822 | unsigned int i; |
| 823 | void *tret; |
| 824 | |
| 825 | ret = parse_arguments(argc, argv); |
| 826 | |
| 827 | if(ret != 0) show_arguments(); |
| 828 | if(ret < 0) return EINVAL; |
| 829 | if(ret > 0) return 0; |
| 830 | |
| 831 | show_info(); |
| 832 | |
| 833 | if(daemon_mode) { |
| 834 | ret = daemon(0, 0); |
| 835 | |
| 836 | if(ret == -1) { |
| 837 | perror("An error occured while daemonizing."); |
| 838 | exit(-1); |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | /* Connect the signal handlers */ |
| 843 | act.sa_handler = handler; |
| 844 | act.sa_flags = 0; |
| 845 | sigemptyset(&(act.sa_mask)); |
| 846 | sigaddset(&(act.sa_mask), SIGTERM); |
| 847 | sigaddset(&(act.sa_mask), SIGQUIT); |
| 848 | sigaddset(&(act.sa_mask), SIGINT); |
| 849 | sigaction(SIGTERM, &act, NULL); |
| 850 | sigaction(SIGQUIT, &act, NULL); |
| 851 | sigaction(SIGINT, &act, NULL); |
| 852 | |
| 853 | |
| 854 | tids = malloc(sizeof(pthread_t) * num_threads); |
| 855 | for(i=0; i<num_threads; i++) { |
| 856 | ret = pthread_create(&tids[i], NULL, thread_main, (void*)i); |
| 857 | if(ret) { |
| 858 | perror("Error creating thread"); |
| 859 | break; |
| 860 | } |
| 861 | } |
| 862 | |
| 863 | for(i=0; i<num_threads; i++) { |
| 864 | ret = pthread_join(tids[i], &tret); |
| 865 | if(ret) { |
| 866 | perror("Error joining thread"); |
| 867 | break; |
| 868 | } |
| 869 | if((int)tret != 0) { |
| 870 | printf("Error %s occured in thread %u\n", strerror((int)tret), i); |
| 871 | } |
| 872 | } |
| 873 | |
| 874 | free(tids); |
| 875 | |
| 876 | return ret; |
| 877 | } |