libcfs/libcfs/debug.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * libcfs/libcfs/debug.c
  33  *
  34  * Author: Phil Schwan <phil@clusterfs.com>
  35  *
  36  */
  37
  38 # define DEBUG_SUBSYSTEM S_LNET
  39
  40 #include <linux/ctype.h>
  41 #include <linux/kthread.h>
  42 #include <linux/stacktrace.h>
  43 #include <linux/utsname.h>
  44 #include <libcfs/libcfs.h>
  45 #include "tracefile.h"
  46
  47 static char debug_file_name[1024];
  48
  49 unsigned int libcfs_subsystem_debug = ~0;
  50 module_param(libcfs_subsystem_debug, int, 0644);
  51 MODULE_PARM_DESC(libcfs_subsystem_debug, "Lustre kernel debug subsystem mask");
  52 EXPORT_SYMBOL(libcfs_subsystem_debug);
  53
  54 unsigned int libcfs_debug = (D_CANTMASK | D_NETERROR | D_HA | D_CONFIG |
  55                              D_IOCTL | D_LFSCK | D_TTY);
  56 module_param(libcfs_debug, int, 0644);
  57 MODULE_PARM_DESC(libcfs_debug, "Lustre kernel debug mask");
  58 EXPORT_SYMBOL(libcfs_debug);
  59
  60 static int libcfs_param_debug_mb_set(const char *val,
  61                                      cfs_kernel_param_arg_t *kp)
  62 {
  63         int rc;
  64         unsigned int num;
  65
  66         rc = kstrtouint(val, 0, &num);
  67         if (rc < 0)
  68                 return rc;
  69
  70         num = cfs_trace_set_debug_mb(num);
  71
  72         *((unsigned int *)kp->arg) = num;
  73         num = cfs_trace_get_debug_mb();
  74         if (num)
  75                 /* This value is more precise */
  76                 *((unsigned int *)kp->arg) = num;
  77
  78         return 0;
  79 }
  80
  81 /*
  82  * While debug_mb setting look like unsigned int, in fact
  83  * it needs quite a bunch of extra processing, so we define special
  84  * debug_mb parameter type with corresponding methods to handle this case
  85  */
  86 static struct kernel_param_ops param_ops_debug_mb = {
  87         .set = libcfs_param_debug_mb_set,
  88         .get = param_get_uint,
  89 };
  90
  91 #define param_check_debug_mb(name, p) \
  92                 __param_check(name, p, unsigned int)
  93
  94 static unsigned int libcfs_debug_mb;
  95 #ifdef HAVE_KERNEL_PARAM_OPS
  96 module_param(libcfs_debug_mb, debug_mb, 0644);
  97 #else
  98 module_param_call(libcfs_debug_mb, libcfs_param_debug_mb_set, param_get_uint,
  99                   &param_ops_debug_mb, 0644);
 100 #endif
 101 MODULE_PARM_DESC(libcfs_debug_mb, "Total debug buffer size.");
 102
 103 unsigned int libcfs_printk = D_CANTMASK;
 104 module_param(libcfs_printk, uint, 0644);
 105 MODULE_PARM_DESC(libcfs_printk, "Lustre kernel debug console mask");
 106
 107 unsigned int libcfs_console_ratelimit = 1;
 108 module_param(libcfs_console_ratelimit, uint, 0644);
 109 MODULE_PARM_DESC(libcfs_console_ratelimit, "Lustre kernel debug console ratelimit (0 to disable)");
 110
 111 static int param_set_delay_minmax(const char *val,
 112                                   cfs_kernel_param_arg_t *kp,
 113                                   long min, long max)
 114 {
 115         long d;
 116         int sec;
 117         int rc;
 118
 119         rc = kstrtoint(val, 0, &sec);
 120         if (rc)
 121                 return -EINVAL;
 122
 123         /* The sysfs setting is in centiseconds */
 124         d = cfs_time_seconds(sec) / 100;
 125         if (d < min || d > max)
 126                 return -EINVAL;
 127
 128         *((unsigned int *)kp->arg) = d;
 129
 130         return 0;
 131 }
 132
 133 static int param_get_delay(char *buffer, cfs_kernel_param_arg_t *kp)
 134 {
 135         unsigned int d = *(unsigned int *)kp->arg;
 136
 137         param_get_byte(buffer, kp);
 138         return sprintf(buffer, "%lu%c", jiffies_to_msecs(d * 10) / MSEC_PER_SEC,
 139                        strnchr(buffer, PAGE_SIZE, '\n') ? '\n' : '\0');
 140 }
 141
 142 unsigned int libcfs_console_max_delay;
 143 unsigned int libcfs_console_min_delay;
 144
 145 static int param_set_console_max_delay(const char *val,
 146                                        cfs_kernel_param_arg_t *kp)
 147 {
 148         return param_set_delay_minmax(val, kp,
 149                                       libcfs_console_min_delay, INT_MAX);
 150 }
 151
 152 static struct kernel_param_ops param_ops_console_max_delay = {
 153         .set = param_set_console_max_delay,
 154         .get = param_get_delay,
 155 };
 156
 157 #define param_check_console_max_delay(name, p) \
 158                 __param_check(name, p, unsigned int)
 159
 160 #ifdef HAVE_KERNEL_PARAM_OPS
 161 module_param(libcfs_console_max_delay, console_max_delay, 0644);
 162 #else
 163 module_param_call(libcfs_console_max_delay, param_set_console_max_delay,
 164                   param_get_delay, &param_ops_console_max_delay, 0644);
 165 #endif
 166 MODULE_PARM_DESC(libcfs_console_max_delay, "Lustre kernel debug console max delay (jiffies)");
 167
 168 static int param_set_console_min_delay(const char *val,
 169                                        cfs_kernel_param_arg_t *kp)
 170 {
 171         return param_set_delay_minmax(val, kp,
 172                                       1, libcfs_console_max_delay);
 173 }
 174
 175 static struct kernel_param_ops param_ops_console_min_delay = {
 176         .set = param_set_console_min_delay,
 177         .get = param_get_delay,
 178 };
 179
 180 #define param_check_console_min_delay(name, p) \
 181                 __param_check(name, p, unsigned int)
 182
 183 #ifdef HAVE_KERNEL_PARAM_OPS
 184 module_param(libcfs_console_min_delay, console_min_delay, 0644);
 185 #else
 186 module_param_call(libcfs_console_min_delay, param_set_console_min_delay,
 187                   param_get_delay, &param_ops_console_min_delay, 0644);
 188 #endif
 189 MODULE_PARM_DESC(libcfs_console_min_delay, "Lustre kernel debug console min delay (jiffies)");
 190
 191 static int param_set_uint_minmax(const char *val,
 192                                  cfs_kernel_param_arg_t *kp,
 193                                  unsigned int min, unsigned int max)
 194 {
 195         unsigned int num;
 196         int ret;
 197
 198         if (!val)
 199                 return -EINVAL;
 200
 201         ret = kstrtouint(val, 0, &num);
 202         if (ret < 0 || num < min || num > max)
 203                 return -EINVAL;
 204
 205         *((unsigned int *)kp->arg) = num;
 206         return 0;
 207 }
 208
 209 static int param_set_uintpos(const char *val,
 210                              cfs_kernel_param_arg_t *kp)
 211 {
 212         return param_set_uint_minmax(val, kp, 1, -1);
 213 }
 214
 215 static struct kernel_param_ops param_ops_uintpos = {
 216         .set = param_set_uintpos,
 217         .get = param_get_uint,
 218 };
 219
 220 #define param_check_uintpos(name, p) \
 221                 __param_check(name, p, unsigned int)
 222
 223 unsigned int libcfs_console_backoff = CDEBUG_DEFAULT_BACKOFF;
 224 #ifdef HAVE_KERNEL_PARAM_OPS
 225 module_param(libcfs_console_backoff, uintpos, 0644);
 226 #else
 227 module_param_call(libcfs_console_backoff, param_set_uintpos, param_get_uint,
 228                   &param_ops_uintpos, 0644);
 229 #endif
 230 MODULE_PARM_DESC(libcfs_console_backoff, "Lustre kernel debug console backoff factor");
 231
 232 unsigned int libcfs_debug_binary = 1;
 233
 234 unsigned int libcfs_stack = 3 * THREAD_SIZE / 4;
 235 EXPORT_SYMBOL(libcfs_stack);
 236
 237 unsigned int libcfs_catastrophe;
 238 EXPORT_SYMBOL(libcfs_catastrophe);
 239
 240 unsigned int libcfs_watchdog_ratelimit = 300;
 241 EXPORT_SYMBOL(libcfs_watchdog_ratelimit);
 242
 243 unsigned int libcfs_panic_on_lbug = 1;
 244 module_param(libcfs_panic_on_lbug, uint, 0644);
 245 MODULE_PARM_DESC(libcfs_panic_on_lbug, "Lustre kernel panic on LBUG");
 246
 247 atomic_t libcfs_kmemory = ATOMIC_INIT(0);
 248 EXPORT_SYMBOL(libcfs_kmemory);
 249
 250 static DECLARE_COMPLETION(debug_complete);
 251
 252 char libcfs_debug_file_path_arr[PATH_MAX] = LIBCFS_DEBUG_FILE_PATH_DEFAULT;
 253 EXPORT_SYMBOL(libcfs_debug_file_path_arr);
 254
 255 /* We need to pass a pointer here, but elsewhere this must be a const */
 256 static char *libcfs_debug_file_path = LIBCFS_DEBUG_FILE_PATH_DEFAULT;
 257 module_param(libcfs_debug_file_path, charp, 0644);
 258 MODULE_PARM_DESC(libcfs_debug_file_path,
 259                  "Path for dumping debug logs, set 'NONE' to prevent log dumping");
 260
 261 int libcfs_panic_in_progress;
 262
 263 /*
 264  * libcfs_debug_token2mask() expects the returned
 265  * string in lower-case
 266  */
 267 static const char *libcfs_debug_subsys2str(int subsys)
 268 {
 269         static const char *libcfs_debug_subsystems[] = LIBCFS_DEBUG_SUBSYS_NAMES;
 270
 271         if (subsys >= ARRAY_SIZE(libcfs_debug_subsystems))
 272                 return NULL;
 273
 274         return libcfs_debug_subsystems[subsys];
 275 }
 276
 277 /*
 278  * libcfs_debug_token2mask() expects the returned
 279  * string in lower-case
 280  */
 281 static const char *libcfs_debug_dbg2str(int debug)
 282 {
 283         static const char *libcfs_debug_masks[] = LIBCFS_DEBUG_MASKS_NAMES;
 284
 285         if (debug >= ARRAY_SIZE(libcfs_debug_masks))
 286                 return NULL;
 287
 288         return libcfs_debug_masks[debug];
 289 }
 290
 291 int
 292 libcfs_debug_mask2str(char *str, int size, int mask, int is_subsys)
 293 {
 294         const char *(*fn)(int bit) = is_subsys ? libcfs_debug_subsys2str :
 295                                                  libcfs_debug_dbg2str;
 296         int len = 0;
 297         const char *token;
 298         int i;
 299
 300         if (mask == 0) {                        /* "0" */
 301                 if (size > 0)
 302                         str[0] = '0';
 303                 len = 1;
 304         } else {                                /* space-separated tokens */
 305                 for (i = 0; i < 32; i++) {
 306                         if ((mask & BIT(i)) == 0)
 307                                 continue;
 308
 309                         token = fn(i);
 310                         if (token == NULL)      /* unused bit */
 311                                 continue;
 312
 313                         if (len > 0) {          /* separator? */
 314                                 if (len < size)
 315                                         str[len] = ' ';
 316                                 len++;
 317                         }
 318
 319                         while (*token != 0) {
 320                                 if (len < size)
 321                                         str[len] = *token;
 322                                 token++;
 323                                 len++;
 324                         }
 325                 }
 326         }
 327
 328         /* terminate 'str' */
 329         if (len < size)
 330                 str[len] = 0;
 331         else
 332                 str[size - 1] = 0;
 333
 334         return len;
 335 }
 336
 337 int
 338 libcfs_debug_str2mask(int *mask, const char *str, int is_subsys)
 339 {
 340         const char *(*fn)(int bit) = is_subsys ? libcfs_debug_subsys2str :
 341                                                  libcfs_debug_dbg2str;
 342         int m = 0;
 343         int matched;
 344         int n;
 345         int t;
 346
 347         /* Allow a number for backwards compatibility */
 348         for (n = strlen(str); n > 0; n--)
 349                 if (!isspace(str[n-1]))
 350                         break;
 351         matched = n;
 352
 353         t = sscanf(str, "%i%n", &m, &matched);
 354         if (t >= 1 && matched == n) {
 355                 /* don't print warning for lctl set_param debug=0 or -1 */
 356                 if (m != 0 && m != -1)
 357                         CWARN("You are trying to use a numerical value for the "
 358                               "mask - this will be deprecated in a future "
 359                               "release.\n");
 360                 *mask = m;
 361                 return 0;
 362         }
 363
 364         return cfs_str2mask(str, fn, mask, is_subsys ? 0 : D_CANTMASK,
 365                             0xffffffff);
 366 }
 367
 368 char lnet_debug_log_upcall[1024] = "/usr/lib/lustre/lnet_debug_log_upcall";
 369
 370 /* Upcall function once a Lustre log has been dumped.
 371  *
 372  * @file        path of the dumped log
 373  */
 374 void libcfs_run_debug_log_upcall(char *file)
 375 {
 376         char *argv[3];
 377         int rc;
 378         char *envp[] = {
 379                 "HOME=/",
 380                 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
 381                 NULL
 382         };
 383
 384         ENTRY;
 385         argv[0] = lnet_debug_log_upcall;
 386
 387         LASSERTF(file, "called on a null filename\n");
 388         argv[1] = file; //only need to pass the path of the file
 389
 390         argv[2] = NULL;
 391
 392         rc = call_usermodehelper(argv[0], argv, envp, 1);
 393         if (rc < 0 && rc != -ENOENT) {
 394                 CERROR("Error %d invoking LNET debug log upcall %s %s; check /sys/kernel/debug/lnet/debug_log_upcall\n",
 395                        rc, argv[0], argv[1]);
 396         } else {
 397                 CDEBUG(D_HA, "Invoked LNET debug log upcall %s %s\n",
 398                        argv[0], argv[1]);
 399         }
 400 }
 401
 402 /**
 403  * Dump Lustre log to ::debug_file_path by calling tracefile_dump_all_pages()
 404  */
 405 void libcfs_debug_dumplog_internal(void *arg)
 406 {
 407         static time64_t last_dump_time;
 408         time64_t current_time;
 409         void *journal_info;
 410
 411         journal_info = current->journal_info;
 412         current->journal_info = NULL;
 413         current_time = ktime_get_real_seconds();
 414
 415         if (strncmp(libcfs_debug_file_path_arr, "NONE", 4) != 0 &&
 416             current_time > last_dump_time) {
 417                 last_dump_time = current_time;
 418                 snprintf(debug_file_name, sizeof(debug_file_name) - 1,
 419                          "%s.%lld.%ld", libcfs_debug_file_path_arr,
 420                          (s64)current_time, (uintptr_t)arg);
 421                 pr_alert("LustreError: dumping log to %s\n", debug_file_name);
 422                 cfs_tracefile_dump_all_pages(debug_file_name);
 423                 libcfs_run_debug_log_upcall(debug_file_name);
 424         }
 425         current->journal_info = journal_info;
 426 }
 427
 428 static int libcfs_debug_dumplog_thread(void *arg)
 429 {
 430         libcfs_debug_dumplog_internal(arg);
 431         complete(&debug_complete);
 432         return 0;
 433 }
 434
 435 static DEFINE_MUTEX(libcfs_debug_dumplog_lock);
 436
 437 void libcfs_debug_dumplog(void)
 438 {
 439         struct task_struct *dumper;
 440
 441         ENTRY;
 442
 443         if (mutex_trylock(&libcfs_debug_dumplog_lock) == 0)
 444                 return;
 445
 446         /* If a previous call was interrupted, debug_complete->done
 447          * might be elevated, and so we won't actually wait here.
 448          * So we reinit the completion to ensure we wait for
 449          * one thread to complete, though it might not be the one
 450          * we start if there are overlaping thread.
 451          */
 452         reinit_completion(&debug_complete);
 453         dumper = kthread_run(libcfs_debug_dumplog_thread,
 454                              (void *)(long)current->pid,
 455                              "libcfs_debug_dumper");
 456         if (IS_ERR(dumper))
 457                 pr_err("LustreError: cannot start log dump thread: rc = %ld\n",
 458                        PTR_ERR(dumper));
 459         else
 460                 wait_for_completion_interruptible(&debug_complete);
 461
 462         mutex_unlock(&libcfs_debug_dumplog_lock);
 463 }
 464 EXPORT_SYMBOL(libcfs_debug_dumplog);
 465
 466 /* coverity[+kill] */
 467 void lbug_with_loc(struct libcfs_debug_msg_data *msgdata)
 468 {
 469         libcfs_catastrophe = 1;
 470         libcfs_debug_msg(msgdata, "LBUG\n");
 471
 472         if (in_interrupt()) {
 473                 panic("LBUG in interrupt.\n");
 474                 /* not reached */
 475         }
 476
 477         libcfs_debug_dumpstack(NULL);
 478         if (libcfs_panic_on_lbug)
 479                 panic("LBUG");
 480         else
 481                 libcfs_debug_dumplog();
 482         set_current_state(TASK_UNINTERRUPTIBLE);
 483         while (1)
 484                 schedule();
 485 }
 486 EXPORT_SYMBOL(lbug_with_loc);
 487
 488 #ifdef CONFIG_STACKTRACE
 489
 490 #ifndef HAVE_SAVE_STACK_TRACE_TSK
 491 #define save_stack_trace_tsk(tsk, trace)                                       \
 492 do {                                                                           \
 493         if (tsk == current)                                                    \
 494                 save_stack_trace(trace);                                       \
 495         else                                                                   \
 496                 pr_info("No stack, save_stack_trace_tsk() not exported\n");    \
 497 } while (0)
 498 #endif
 499
 500 #define MAX_ST_ENTRIES  100
 501 static DEFINE_SPINLOCK(st_lock);
 502
 503 /* Linux v5.1-rc5 214d8ca6ee ("stacktrace: Provide common infrastructure")
 504  * CONFIG_ARCH_STACKWALK indicates that save_stack_trace_tsk symbol is not
 505  * exported. Use symbol_get() to find if save_stack_trace_tsk is available.
 506  */
 507 #ifdef CONFIG_ARCH_STACKWALK
 508 typedef unsigned int (stack_trace_save_tsk_t)(struct task_struct *task,
 509                                               unsigned long *store,
 510                                               unsigned int size,
 511                                               unsigned int skipnr);
 512 static stack_trace_save_tsk_t *task_dump_stack;
 513 #endif
 514
 515 static void libcfs_call_trace(struct task_struct *tsk)
 516 {
 517 #ifdef CONFIG_ARCH_STACKWALK
 518         static unsigned long entries[MAX_ST_ENTRIES];
 519         unsigned int i, nr_entries;
 520
 521         if (!task_dump_stack)
 522                 task_dump_stack = (stack_trace_save_tsk_t *)
 523                                   symbol_get("stack_trace_save_tsk");
 524
 525         spin_lock(&st_lock);
 526         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 527                 init_utsname()->release, init_utsname()->version);
 528         pr_info("Call Trace TBD:\n");
 529         if (task_dump_stack) {
 530                 nr_entries = task_dump_stack(tsk, entries, MAX_ST_ENTRIES, 0);
 531                 for (i = 0; i < nr_entries; i++)
 532                         pr_info("[<0>] %pB\n", (void *)entries[i]);
 533         }
 534         spin_unlock(&st_lock);
 535 #else
 536         struct stack_trace trace;
 537         static unsigned long entries[MAX_ST_ENTRIES];
 538
 539         trace.nr_entries = 0;
 540         trace.max_entries = MAX_ST_ENTRIES;
 541         trace.entries = entries;
 542         trace.skip = 0;
 543
 544         spin_lock(&st_lock);
 545         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 546                 init_utsname()->release, init_utsname()->version);
 547         pr_info("Call Trace:\n");
 548         save_stack_trace_tsk(tsk, &trace);
 549         print_stack_trace(&trace, 0);
 550         spin_unlock(&st_lock);
 551 #endif
 552 }
 553
 554 #else /* !CONFIG_STACKTRACE */
 555
 556 #ifdef CONFIG_X86
 557 #include <linux/nmi.h>
 558 #include <asm/stacktrace.h>
 559
 560 #ifdef HAVE_STACKTRACE_OPS
 561 static int print_trace_stack(void *data, char *name)
 562 {
 563         printk(" <%s> ", name);
 564         return 0;
 565 }
 566
 567 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 568 static int
 569 #else
 570 static void
 571 #endif
 572 print_trace_address(void *data, unsigned long addr, int reliable)
 573 {
 574         char fmt[32];
 575
 576         touch_nmi_watchdog();
 577         sprintf(fmt, " [<%016lx>] %s%%s\n", addr, reliable ? "" : "? ");
 578         __print_symbol(fmt, addr);
 579 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 580         return 0;
 581 #endif
 582 }
 583
 584 static const struct stacktrace_ops print_trace_ops = {
 585         .stack          = print_trace_stack,
 586         .address        = print_trace_address,
 587         .walk_stack     = print_context_stack,
 588 };
 589 #endif /* HAVE_STACKTRACE_OPS */
 590
 591 static void libcfs_call_trace(struct task_struct *tsk)
 592 {
 593 #ifdef HAVE_STACKTRACE_OPS
 594         printk("Pid: %d, comm: %.20s\n", tsk->pid, tsk->comm);
 595         printk("\nCall Trace:\n");
 596         dump_trace(tsk, NULL, NULL, 0, &print_trace_ops, NULL);
 597         printk("\n");
 598 #else /* !HAVE_STACKTRACE_OPS */
 599         if (tsk == current)
 600                 dump_stack();
 601         else
 602                 CWARN("can't show stack: kernel doesn't export show_task\n");
 603 #endif /* HAVE_STACKTRACE_OPS */
 604 }
 605
 606 #else /* !CONFIG_X86 */
 607
 608 static void libcfs_call_trace(struct task_struct *tsk)
 609 {
 610         if (tsk == current)
 611                 dump_stack();
 612         else
 613                 CWARN("can't show stack: kernel doesn't export show_task\n");
 614 }
 615
 616 #endif /* CONFIG_X86 */
 617
 618 #endif /* CONFIG_STACKTRACE */
 619
 620 void libcfs_debug_dumpstack(struct task_struct *tsk)
 621 {
 622         libcfs_call_trace(tsk ?: current);
 623 }
 624 EXPORT_SYMBOL(libcfs_debug_dumpstack);
 625
 626 static int panic_notifier(struct notifier_block *self, unsigned long unused1,
 627                           void *unused2)
 628 {
 629         if (libcfs_panic_in_progress)
 630                 return 0;
 631
 632         libcfs_panic_in_progress = 1;
 633         mb();
 634
 635         return 0;
 636 }
 637
 638 static struct notifier_block libcfs_panic_notifier = {
 639         .notifier_call          = panic_notifier,
 640         .next                   = NULL,
 641         .priority               = 10000,
 642 };
 643
 644 static void libcfs_register_panic_notifier(void)
 645 {
 646         atomic_notifier_chain_register(&panic_notifier_list,
 647                                        &libcfs_panic_notifier);
 648 }
 649
 650 static void libcfs_unregister_panic_notifier(void)
 651 {
 652         atomic_notifier_chain_unregister(&panic_notifier_list,
 653                                          &libcfs_panic_notifier);
 654 }
 655
 656 int libcfs_debug_init(unsigned long bufsize)
 657 {
 658         int rc = 0;
 659         unsigned int max = libcfs_debug_mb;
 660
 661         if (libcfs_console_max_delay <= 0 || /* not set by user or */
 662             libcfs_console_min_delay <= 0 || /* set to invalid values */
 663             libcfs_console_min_delay >= libcfs_console_max_delay) {
 664                 libcfs_console_max_delay = CDEBUG_DEFAULT_MAX_DELAY;
 665                 libcfs_console_min_delay = CDEBUG_DEFAULT_MIN_DELAY;
 666         }
 667
 668         if (libcfs_debug_file_path != NULL) {
 669                 strlcpy(libcfs_debug_file_path_arr,
 670                         libcfs_debug_file_path,
 671                         sizeof(libcfs_debug_file_path_arr));
 672         }
 673
 674         /* If libcfs_debug_mb is uninitialized then just make the
 675          * total buffers smp_num_cpus * TCD_MAX_PAGES
 676          */
 677         if (max < num_possible_cpus()) {
 678                 max = TCD_MAX_PAGES;
 679         } else {
 680                 max = (max / num_possible_cpus());
 681                 max = (max << (20 - PAGE_SHIFT));
 682         }
 683
 684         rc = cfs_tracefile_init(max);
 685         if (rc)
 686                 return rc;
 687
 688         libcfs_register_panic_notifier();
 689         kernel_param_lock(THIS_MODULE);
 690         if (libcfs_debug_mb == 0)
 691                 libcfs_debug_mb = cfs_trace_get_debug_mb();
 692         kernel_param_unlock(THIS_MODULE);
 693         return rc;
 694 }
 695
 696 int libcfs_debug_cleanup(void)
 697 {
 698         libcfs_unregister_panic_notifier();
 699         kernel_param_lock(THIS_MODULE);
 700         cfs_tracefile_exit();
 701         kernel_param_unlock(THIS_MODULE);
 702         return 0;
 703 }
 704
 705 int libcfs_debug_clear_buffer(void)
 706 {
 707         cfs_trace_flush_pages();
 708         return 0;
 709 }
 710
 711 /*
 712  * Debug markers, although printed by S_LNET
 713  * should not be be marked as such.
 714  */
 715 #undef DEBUG_SUBSYSTEM
 716 #define DEBUG_SUBSYSTEM S_UNDEFINED
 717 int libcfs_debug_mark_buffer(const char *text)
 718 {
 719         CDEBUG(D_TRACE, "**************************************************\n");
 720         LCONSOLE(D_WARNING, "DEBUG MARKER: %s\n", text);
 721         CDEBUG(D_TRACE, "**************************************************\n");
 722
 723         return 0;
 724 }
 725 #undef DEBUG_SUBSYSTEM
 726 #define DEBUG_SUBSYSTEM S_LNET
 727
 728 long libcfs_log_return(struct libcfs_debug_msg_data *msgdata, long rc)
 729 {
 730         libcfs_debug_msg(msgdata, "Process leaving (rc=%lu : %ld : %lx)\n",
 731                          rc, rc, rc);
 732         return rc;
 733 }
 734 EXPORT_SYMBOL(libcfs_log_return);
 735
 736 void libcfs_log_goto(struct libcfs_debug_msg_data *msgdata, const char *label,
 737                      long rc)
 738 {
 739         libcfs_debug_msg(msgdata, "Process leaving via %s (rc=%lu : %ld"
 740                          " : %#lx)\n", label, rc, rc, rc);
 741 }
 742 EXPORT_SYMBOL(libcfs_log_goto);