granicus.if.org Git - zfs/blob - module/spl/spl-debug.c

   1 /*****************************************************************************\
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://github.com/behlendorf/spl/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  *****************************************************************************
  24  *  Solaris Porting Layer (SPL) Debug Implementation.
  25 \*****************************************************************************/
  26
  27 #include <linux/kmod.h>
  28 #include <linux/mm.h>
  29 #include <linux/vmalloc.h>
  30 #include <linux/pagemap.h>
  31 #include <linux/slab.h>
  32 #include <linux/ctype.h>
  33 #include <linux/kthread.h>
  34 #include <linux/hardirq.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/spinlock.h>
  37 #include <sys/sysmacros.h>
  38 #include <sys/proc.h>
  39 #include <sys/debug.h>
  40 #include <spl-ctl.h>
  41
  42 #ifdef DEBUG_SUBSYSTEM
  43 #undef DEBUG_SUBSYSTEM
  44 #endif
  45
  46 #define DEBUG_SUBSYSTEM S_DEBUG
  47
  48 unsigned long spl_debug_subsys = ~0;
  49 EXPORT_SYMBOL(spl_debug_subsys);
  50 module_param(spl_debug_subsys, long, 0644);
  51 MODULE_PARM_DESC(spl_debug_subsys, "Subsystem debugging level mask.");
  52
  53 unsigned long spl_debug_mask = (D_EMERG | D_ERROR | D_WARNING | D_CONSOLE);
  54 EXPORT_SYMBOL(spl_debug_mask);
  55 module_param(spl_debug_mask, long, 0644);
  56 MODULE_PARM_DESC(spl_debug_mask, "Debugging level mask.");
  57
  58 unsigned long spl_debug_printk = D_CANTMASK;
  59 EXPORT_SYMBOL(spl_debug_printk);
  60 module_param(spl_debug_printk, long, 0644);
  61 MODULE_PARM_DESC(spl_debug_printk, "Console printk level mask.");
  62
  63 int spl_debug_mb = -1;
  64 EXPORT_SYMBOL(spl_debug_mb);
  65 module_param(spl_debug_mb, int, 0644);
  66 MODULE_PARM_DESC(spl_debug_mb, "Total debug buffer size.");
  67
  68 unsigned int spl_debug_binary = 1;
  69 EXPORT_SYMBOL(spl_debug_binary);
  70
  71 unsigned int spl_debug_catastrophe;
  72 EXPORT_SYMBOL(spl_debug_catastrophe);
  73
  74 unsigned int spl_debug_panic_on_bug = 0;
  75 EXPORT_SYMBOL(spl_debug_panic_on_bug);
  76 module_param(spl_debug_panic_on_bug, int, 0644);
  77 MODULE_PARM_DESC(spl_debug_panic_on_bug, "Panic on BUG");
  78
  79 static char spl_debug_file_name[PATH_MAX];
  80 char spl_debug_file_path[PATH_MAX] = "/tmp/spl-log";
  81
  82 unsigned int spl_console_ratelimit = 1;
  83 EXPORT_SYMBOL(spl_console_ratelimit);
  84
  85 long spl_console_max_delay;
  86 EXPORT_SYMBOL(spl_console_max_delay);
  87
  88 long spl_console_min_delay;
  89 EXPORT_SYMBOL(spl_console_min_delay);
  90
  91 unsigned int spl_console_backoff = SPL_DEFAULT_BACKOFF;
  92 EXPORT_SYMBOL(spl_console_backoff);
  93
  94 unsigned int spl_debug_stack;
  95 EXPORT_SYMBOL(spl_debug_stack);
  96
  97 static int spl_panic_in_progress;
  98
  99 union trace_data_union (*trace_data[TCD_TYPE_MAX])[NR_CPUS] __cacheline_aligned;
 100 char *trace_console_buffers[NR_CPUS][3];
 101 struct rw_semaphore trace_sem;
 102 atomic_t trace_tage_allocated = ATOMIC_INIT(0);
 103
 104 static int spl_debug_dump_all_pages(dumplog_priv_t *dp, char *);
 105 static void trace_fini(void);
 106
 107
 108 /* Memory percentage breakdown by type */
 109 static unsigned int pages_factor[TCD_TYPE_MAX] = {
 110        80,  /* 80% pages for TCD_TYPE_PROC */
 111        10,  /* 10% pages for TCD_TYPE_SOFTIRQ */
 112        10   /* 10% pages for TCD_TYPE_IRQ */
 113 };
 114
 115 const char *
 116 spl_debug_subsys2str(int subsys)
 117 {
 118         switch (subsys) {
 119         default:
 120                 return NULL;
 121         case S_UNDEFINED:
 122                 return "undefined";
 123         case S_ATOMIC:
 124                 return "atomic";
 125         case S_KOBJ:
 126                 return "kobj";
 127         case S_VNODE:
 128                 return "vnode";
 129         case S_TIME:
 130                 return "time";
 131         case S_RWLOCK:
 132                 return "rwlock";
 133         case S_THREAD:
 134                 return "thread";
 135         case S_CONDVAR:
 136                 return "condvar";
 137         case S_MUTEX:
 138                 return "mutex";
 139         case S_RNG:
 140                 return "rng";
 141         case S_TASKQ:
 142                 return "taskq";
 143         case S_KMEM:
 144                 return "kmem";
 145         case S_DEBUG:
 146                 return "debug";
 147         case S_GENERIC:
 148                 return "generic";
 149         case S_PROC:
 150                 return "proc";
 151         case S_MODULE:
 152                 return "module";
 153         case S_CRED:
 154                 return "cred";
 155         }
 156 }
 157
 158 const char *
 159 spl_debug_dbg2str(int debug)
 160 {
 161         switch (debug) {
 162         default:
 163                 return NULL;
 164         case D_TRACE:
 165                 return "trace";
 166         case D_INFO:
 167                 return "info";
 168         case D_WARNING:
 169                 return "warning";
 170         case D_ERROR:
 171                 return "error";
 172         case D_EMERG:
 173                 return "emerg";
 174         case D_CONSOLE:
 175                 return "console";
 176         case D_IOCTL:
 177                 return "ioctl";
 178         case D_DPRINTF:
 179                 return "dprintf";
 180         case D_OTHER:
 181                 return "other";
 182         }
 183 }
 184
 185 int
 186 spl_debug_mask2str(char *str, int size, unsigned long mask, int is_subsys)
 187 {
 188         const char *(*fn)(int bit) = is_subsys ? spl_debug_subsys2str :
 189                                                  spl_debug_dbg2str;
 190         const char *token;
 191         int i, bit, len = 0;
 192
 193         if (mask == 0) {                        /* "0" */
 194                 if (size > 0)
 195                         str[0] = '0';
 196                 len = 1;
 197         } else {                                /* space-separated tokens */
 198                 for (i = 0; i < 32; i++) {
 199                         bit = 1 << i;
 200
 201                         if ((mask & bit) == 0)
 202                                 continue;
 203
 204                         token = fn(bit);
 205                         if (token == NULL)              /* unused bit */
 206                                 continue;
 207
 208                         if (len > 0) {                  /* separator? */
 209                                 if (len < size)
 210                                         str[len] = ' ';
 211                                 len++;
 212                         }
 213
 214                         while (*token != 0) {
 215                                 if (len < size)
 216                                         str[len] = *token;
 217                                 token++;
 218                                 len++;
 219                         }
 220                 }
 221         }
 222
 223         /* terminate 'str' */
 224         if (len < size)
 225                 str[len] = 0;
 226         else
 227                 str[size - 1] = 0;
 228
 229         return len;
 230 }
 231
 232 static int
 233 spl_debug_token2mask(int *mask, const char *str, int len, int is_subsys)
 234 {
 235         const char *(*fn)(int bit) = is_subsys ? spl_debug_subsys2str :
 236                                                  spl_debug_dbg2str;
 237         const char   *token;
 238         int i, j, bit;
 239
 240         /* match against known tokens */
 241         for (i = 0; i < 32; i++) {
 242                 bit = 1 << i;
 243
 244                 token = fn(bit);
 245                 if (token == NULL)              /* unused? */
 246                         continue;
 247
 248                 /* strcasecmp */
 249                 for (j = 0; ; j++) {
 250                         if (j == len) {         /* end of token */
 251                                 if (token[j] == 0) {
 252                                         *mask = bit;
 253                                         return 0;
 254                                 }
 255                                 break;
 256                         }
 257
 258                         if (token[j] == 0)
 259                                 break;
 260
 261                         if (str[j] == token[j])
 262                                 continue;
 263
 264                         if (str[j] < 'A' || 'Z' < str[j])
 265                                 break;
 266
 267                         if (str[j] - 'A' + 'a' != token[j])
 268                                 break;
 269                 }
 270         }
 271
 272         return -EINVAL;                         /* no match */
 273 }
 274
 275 int
 276 spl_debug_str2mask(unsigned long *mask, const char *str, int is_subsys)
 277 {
 278         char op = 0;
 279         int m = 0, matched, n, t;
 280
 281         /* Allow a number for backwards compatibility */
 282         for (n = strlen(str); n > 0; n--)
 283                 if (!isspace(str[n-1]))
 284                         break;
 285         matched = n;
 286
 287         if ((t = sscanf(str, "%i%n", &m, &matched)) >= 1 && matched == n) {
 288                 *mask = m;
 289                 return 0;
 290         }
 291
 292         /* <str> must be a list of debug tokens or numbers separated by
 293          * whitespace and optionally an operator ('+' or '-').  If an operator
 294          * appears first in <str>, '*mask' is used as the starting point
 295          * (relative), otherwise 0 is used (absolute).  An operator applies to
 296          * all following tokens up to the next operator. */
 297         matched = 0;
 298         while (*str != 0) {
 299                 while (isspace(*str)) /* skip whitespace */
 300                         str++;
 301
 302                 if (*str == 0)
 303                         break;
 304
 305                 if (*str == '+' || *str == '-') {
 306                         op = *str++;
 307
 308                         /* op on first token == relative */
 309                         if (!matched)
 310                                 m = *mask;
 311
 312                         while (isspace(*str)) /* skip whitespace */
 313                                 str++;
 314
 315                         if (*str == 0)          /* trailing op */
 316                                 return -EINVAL;
 317                 }
 318
 319                 /* find token length */
 320                 for (n = 0; str[n] != 0 && !isspace(str[n]); n++);
 321
 322                 /* match token */
 323                 if (spl_debug_token2mask(&t, str, n, is_subsys) != 0)
 324                         return -EINVAL;
 325
 326                 matched = 1;
 327                 if (op == '-')
 328                         m &= ~t;
 329                 else
 330                         m |= t;
 331
 332                 str += n;
 333         }
 334
 335         if (!matched)
 336                 return -EINVAL;
 337
 338         *mask = m;
 339         return 0;
 340 }
 341
 342 static void
 343 spl_debug_dumplog_internal(dumplog_priv_t *dp)
 344 {
 345         void *journal_info;
 346
 347         journal_info = current->journal_info;
 348         current->journal_info = NULL;
 349
 350         snprintf(spl_debug_file_name, sizeof(spl_debug_file_path) - 1,
 351                  "%s.%ld.%ld", spl_debug_file_path,
 352                  get_seconds(), (long)dp->dp_pid);
 353         printk("SPL: Dumping log to %s\n", spl_debug_file_name);
 354         spl_debug_dump_all_pages(dp, spl_debug_file_name);
 355
 356         current->journal_info = journal_info;
 357 }
 358
 359 static int
 360 spl_debug_dumplog_thread(void *arg)
 361 {
 362         dumplog_priv_t *dp = (dumplog_priv_t *)arg;
 363
 364         spl_debug_dumplog_internal(dp);
 365         atomic_set(&dp->dp_done, 1);
 366         wake_up(&dp->dp_waitq);
 367         complete_and_exit(NULL, 0);
 368
 369         return 0; /* Unreachable */
 370 }
 371
 372 /* When flag is set do not use a new thread for the debug dump */
 373 int
 374 spl_debug_dumplog(int flags)
 375 {
 376         struct task_struct *tsk;
 377         dumplog_priv_t dp;
 378
 379         init_waitqueue_head(&dp.dp_waitq);
 380         dp.dp_pid = current->pid;
 381         dp.dp_flags = flags;
 382         atomic_set(&dp.dp_done, 0);
 383
 384         if (dp.dp_flags & DL_NOTHREAD) {
 385                 spl_debug_dumplog_internal(&dp);
 386         } else {
 387
 388                 tsk = kthread_create(spl_debug_dumplog_thread,(void *)&dp,"spl_debug");
 389                 if (tsk == NULL)
 390                         return -ENOMEM;
 391
 392                 wake_up_process(tsk);
 393                 wait_event(dp.dp_waitq, atomic_read(&dp.dp_done));
 394         }
 395
 396         return 0;
 397 }
 398 EXPORT_SYMBOL(spl_debug_dumplog);
 399
 400 static char *
 401 trace_get_console_buffer(void)
 402 {
 403         int  cpu = get_cpu();
 404         int  idx;
 405
 406         if (in_irq()) {
 407                 idx = 0;
 408         } else if (in_softirq()) {
 409                 idx = 1;
 410         } else {
 411                 idx = 2;
 412         }
 413
 414         return trace_console_buffers[cpu][idx];
 415 }
 416
 417 static void
 418 trace_put_console_buffer(char *buffer)
 419 {
 420         put_cpu();
 421 }
 422
 423 static int
 424 trace_lock_tcd(struct trace_cpu_data *tcd)
 425 {
 426         __ASSERT(tcd->tcd_type < TCD_TYPE_MAX);
 427
 428         spin_lock_irqsave(&tcd->tcd_lock, tcd->tcd_lock_flags);
 429
 430         return 1;
 431 }
 432
 433 static void
 434 trace_unlock_tcd(struct trace_cpu_data *tcd)
 435 {
 436         __ASSERT(tcd->tcd_type < TCD_TYPE_MAX);
 437
 438         spin_unlock_irqrestore(&tcd->tcd_lock, tcd->tcd_lock_flags);
 439 }
 440
 441 static struct trace_cpu_data *
 442 trace_get_tcd(void)
 443 {
 444         int cpu;
 445         struct trace_cpu_data *tcd;
 446
 447         cpu = get_cpu();
 448         if (in_irq())
 449                 tcd = &(*trace_data[TCD_TYPE_IRQ])[cpu].tcd;
 450         else if (in_softirq())
 451                 tcd = &(*trace_data[TCD_TYPE_SOFTIRQ])[cpu].tcd;
 452         else
 453                 tcd = &(*trace_data[TCD_TYPE_PROC])[cpu].tcd;
 454
 455         trace_lock_tcd(tcd);
 456
 457         return tcd;
 458 }
 459
 460 static void
 461 trace_put_tcd (struct trace_cpu_data *tcd)
 462 {
 463         trace_unlock_tcd(tcd);
 464
 465         put_cpu();
 466 }
 467
 468 static void
 469 trace_set_debug_header(struct spl_debug_header *header, int subsys,
 470                        int mask, const int line, unsigned long stack)
 471 {
 472         struct timeval tv;
 473
 474         do_gettimeofday(&tv);
 475
 476         header->ph_subsys = subsys;
 477         header->ph_mask = mask;
 478         header->ph_cpu_id = smp_processor_id();
 479         header->ph_sec = (__u32)tv.tv_sec;
 480         header->ph_usec = tv.tv_usec;
 481         header->ph_stack = stack;
 482         header->ph_pid = current->pid;
 483         header->ph_line_num = line;
 484
 485         return;
 486 }
 487
 488 static void
 489 trace_print_to_console(struct spl_debug_header *hdr, int mask, const char *buf,
 490                        int len, const char *file, const char *fn)
 491 {
 492         char *prefix = "SPL", *ptype = NULL;
 493
 494         if ((mask & D_EMERG) != 0) {
 495                 prefix = "SPLError";
 496                 ptype = KERN_EMERG;
 497         } else if ((mask & D_ERROR) != 0) {
 498                 prefix = "SPLError";
 499                 ptype = KERN_ERR;
 500         } else if ((mask & D_WARNING) != 0) {
 501                 prefix = "SPL";
 502                 ptype = KERN_WARNING;
 503         } else if ((mask & (D_CONSOLE | spl_debug_printk)) != 0) {
 504                 prefix = "SPL";
 505                 ptype = KERN_INFO;
 506         }
 507
 508         if ((mask & D_CONSOLE) != 0) {
 509                 printk("%s%s: %.*s", ptype, prefix, len, buf);
 510         } else {
 511                 printk("%s%s: %d:%d:(%s:%d:%s()) %.*s", ptype, prefix,
 512                        hdr->ph_pid, hdr->ph_stack, file,
 513                        hdr->ph_line_num, fn, len, buf);
 514         }
 515
 516         return;
 517 }
 518
 519 static int
 520 trace_max_debug_mb(void)
 521 {
 522         return MAX(512, ((num_physpages >> (20 - PAGE_SHIFT)) * 80) / 100);
 523 }
 524
 525 static struct trace_page *
 526 tage_alloc(int gfp)
 527 {
 528         struct page *page;
 529         struct trace_page *tage;
 530
 531         page = alloc_pages(gfp | __GFP_NOWARN, 0);
 532         if (page == NULL)
 533                 return NULL;
 534
 535         tage = kmalloc(sizeof(*tage), gfp);
 536         if (tage == NULL) {
 537                 __free_pages(page, 0);
 538                 return NULL;
 539         }
 540
 541         tage->page = page;
 542         atomic_inc(&trace_tage_allocated);
 543
 544         return tage;
 545 }
 546
 547 static void
 548 tage_free(struct trace_page *tage)
 549 {
 550         __ASSERT(tage != NULL);
 551         __ASSERT(tage->page != NULL);
 552
 553         __free_pages(tage->page, 0);
 554         kfree(tage);
 555         atomic_dec(&trace_tage_allocated);
 556 }
 557
 558 static struct trace_page *
 559 tage_from_list(struct list_head *list)
 560 {
 561         return list_entry(list, struct trace_page, linkage);
 562 }
 563
 564 static void
 565 tage_to_tail(struct trace_page *tage, struct list_head *queue)
 566 {
 567         __ASSERT(tage != NULL);
 568         __ASSERT(queue != NULL);
 569
 570         list_move_tail(&tage->linkage, queue);
 571 }
 572
 573 /* try to return a page that has 'len' bytes left at the end */
 574 static struct trace_page *
 575 trace_get_tage_try(struct trace_cpu_data *tcd, unsigned long len)
 576 {
 577         struct trace_page *tage;
 578
 579         if (tcd->tcd_cur_pages > 0) {
 580                 __ASSERT(!list_empty(&tcd->tcd_pages));
 581                 tage = tage_from_list(tcd->tcd_pages.prev);
 582                 if (tage->used + len <= PAGE_SIZE)
 583                         return tage;
 584         }
 585
 586         if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
 587                 if (tcd->tcd_cur_stock_pages > 0) {
 588                         tage = tage_from_list(tcd->tcd_stock_pages.prev);
 589                         tcd->tcd_cur_stock_pages--;
 590                         list_del_init(&tage->linkage);
 591                 } else {
 592                         tage = tage_alloc(GFP_ATOMIC);
 593                         if (tage == NULL) {
 594                                 printk(KERN_WARNING
 595                                        "failure to allocate a tage (%ld)\n",
 596                                        tcd->tcd_cur_pages);
 597                                 return NULL;
 598                         }
 599                 }
 600
 601                 tage->used = 0;
 602                 tage->cpu = smp_processor_id();
 603                 tage->type = tcd->tcd_type;
 604                 list_add_tail(&tage->linkage, &tcd->tcd_pages);
 605                 tcd->tcd_cur_pages++;
 606
 607                 return tage;
 608         }
 609
 610         return NULL;
 611 }
 612
 613 /* return a page that has 'len' bytes left at the end */
 614 static struct trace_page *
 615 trace_get_tage(struct trace_cpu_data *tcd, unsigned long len)
 616 {
 617         struct trace_page *tage;
 618
 619         __ASSERT(len <= PAGE_SIZE);
 620
 621         tage = trace_get_tage_try(tcd, len);
 622         if (tage)
 623                 return tage;
 624
 625         if (tcd->tcd_cur_pages > 0) {
 626                 tage = tage_from_list(tcd->tcd_pages.next);
 627                 tage->used = 0;
 628                 tage_to_tail(tage, &tcd->tcd_pages);
 629         }
 630
 631         return tage;
 632 }
 633
 634 int
 635 spl_debug_vmsg(spl_debug_limit_state_t *cdls, int subsys, int mask,
 636                const char *file, const char *fn, const int line,
 637                const char *format1, va_list args, const char *format2, ...)
 638 {
 639         struct trace_cpu_data   *tcd = NULL;
 640         struct spl_debug_header header = { 0, };
 641         struct trace_page       *tage;
 642         /* string_buf is used only if tcd != NULL, and is always set then */
 643         char                    *string_buf = NULL;
 644         char                    *debug_buf;
 645         int                      known_size;
 646         int                      needed = 85; /* average message length */
 647         int                      max_nob;
 648         va_list                  ap;
 649         int                      i;
 650         int                      remain;
 651
 652         if (strchr(file, '/'))
 653                 file = strrchr(file, '/') + 1;
 654
 655         trace_set_debug_header(&header, subsys, mask, line, CDEBUG_STACK());
 656
 657         tcd = trace_get_tcd();
 658         if (tcd == NULL)
 659                 goto console;
 660
 661         if (tcd->tcd_shutting_down) {
 662                 trace_put_tcd(tcd);
 663                 tcd = NULL;
 664                 goto console;
 665         }
 666
 667         known_size = strlen(file) + 1;
 668         if (fn)
 669                 known_size += strlen(fn) + 1;
 670
 671         if (spl_debug_binary)
 672                 known_size += sizeof(header);
 673
 674         /* '2' used because vsnprintf returns real size required for output
 675          * _without_ terminating NULL. */
 676         for (i = 0; i < 2; i++) {
 677                 tage = trace_get_tage(tcd, needed + known_size + 1);
 678                 if (tage == NULL) {
 679                         if (needed + known_size > PAGE_SIZE)
 680                                 mask |= D_ERROR;
 681
 682                         trace_put_tcd(tcd);
 683                         tcd = NULL;
 684                         goto console;
 685                 }
 686
 687                 string_buf = (char *)page_address(tage->page) +
 688                              tage->used + known_size;
 689
 690                 max_nob = PAGE_SIZE - tage->used - known_size;
 691                 if (max_nob <= 0) {
 692                         printk(KERN_EMERG "negative max_nob: %i\n", max_nob);
 693                         mask |= D_ERROR;
 694                         trace_put_tcd(tcd);
 695                         tcd = NULL;
 696                         goto console;
 697                 }
 698
 699                 needed = 0;
 700                 if (format1) {
 701                         va_copy(ap, args);
 702                         needed = vsnprintf(string_buf, max_nob, format1, ap);
 703                         va_end(ap);
 704                 }
 705
 706                 if (format2) {
 707                         remain = max_nob - needed;
 708                         if (remain < 0)
 709                                 remain = 0;
 710
 711                         va_start(ap, format2);
 712                         needed += vsnprintf(string_buf+needed, remain, format2, ap);
 713                         va_end(ap);
 714                 }
 715
 716                 if (needed < max_nob)
 717                         break;
 718         }
 719
 720         header.ph_len = known_size + needed;
 721         debug_buf = (char *)page_address(tage->page) + tage->used;
 722
 723         if (spl_debug_binary) {
 724                 memcpy(debug_buf, &header, sizeof(header));
 725                 tage->used += sizeof(header);
 726                 debug_buf += sizeof(header);
 727         }
 728
 729         strcpy(debug_buf, file);
 730         tage->used += strlen(file) + 1;
 731         debug_buf += strlen(file) + 1;
 732
 733         if (fn) {
 734                 strcpy(debug_buf, fn);
 735                 tage->used += strlen(fn) + 1;
 736                 debug_buf += strlen(fn) + 1;
 737         }
 738
 739         __ASSERT(debug_buf == string_buf);
 740
 741         tage->used += needed;
 742         __ASSERT (tage->used <= PAGE_SIZE);
 743
 744 console:
 745         if ((mask & spl_debug_printk) == 0) {
 746                 /* no console output requested */
 747                 if (tcd != NULL)
 748                         trace_put_tcd(tcd);
 749                 return 1;
 750         }
 751
 752         if (cdls != NULL) {
 753                 if (spl_console_ratelimit && cdls->cdls_next != 0 &&
 754                     !time_before(cdls->cdls_next, jiffies)) {
 755                         /* skipping a console message */
 756                         cdls->cdls_count++;
 757                         if (tcd != NULL)
 758                                 trace_put_tcd(tcd);
 759                         return 1;
 760                 }
 761
 762                 if (time_before(cdls->cdls_next + spl_console_max_delay +
 763                                 (10 * HZ), jiffies)) {
 764                         /* last timeout was a long time ago */
 765                         cdls->cdls_delay /= spl_console_backoff * 4;
 766                 } else {
 767                         cdls->cdls_delay *= spl_console_backoff;
 768
 769                         if (cdls->cdls_delay < spl_console_min_delay)
 770                                 cdls->cdls_delay = spl_console_min_delay;
 771                         else if (cdls->cdls_delay > spl_console_max_delay)
 772                                 cdls->cdls_delay = spl_console_max_delay;
 773                 }
 774
 775                 /* ensure cdls_next is never zero after it's been seen */
 776                 cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
 777         }
 778
 779         if (tcd != NULL) {
 780                 trace_print_to_console(&header, mask, string_buf, needed, file, fn);
 781                 trace_put_tcd(tcd);
 782         } else {
 783                 string_buf = trace_get_console_buffer();
 784
 785                 needed = 0;
 786                 if (format1 != NULL) {
 787                         va_copy(ap, args);
 788                         needed = vsnprintf(string_buf, TRACE_CONSOLE_BUFFER_SIZE, format1, ap);
 789                         va_end(ap);
 790                 }
 791                 if (format2 != NULL) {
 792                         remain = TRACE_CONSOLE_BUFFER_SIZE - needed;
 793                         if (remain > 0) {
 794                                 va_start(ap, format2);
 795                                 needed += vsnprintf(string_buf+needed, remain, format2, ap);
 796                                 va_end(ap);
 797                         }
 798                 }
 799                 trace_print_to_console(&header, mask,
 800                                  string_buf, needed, file, fn);
 801
 802                 trace_put_console_buffer(string_buf);
 803         }
 804
 805         if (cdls != NULL && cdls->cdls_count != 0) {
 806                 string_buf = trace_get_console_buffer();
 807
 808                 needed = snprintf(string_buf, TRACE_CONSOLE_BUFFER_SIZE,
 809                          "Skipped %d previous similar message%s\n",
 810                          cdls->cdls_count, (cdls->cdls_count > 1) ? "s" : "");
 811
 812                 trace_print_to_console(&header, mask,
 813                                  string_buf, needed, file, fn);
 814
 815                 trace_put_console_buffer(string_buf);
 816                 cdls->cdls_count = 0;
 817         }
 818
 819         return 0;
 820 }
 821 EXPORT_SYMBOL(spl_debug_vmsg);
 822
 823 /* Do the collect_pages job on a single CPU: assumes that all other
 824  * CPUs have been stopped during a panic.  If this isn't true for
 825  * some arch, this will have to be implemented separately in each arch.
 826  */
 827 static void
 828 collect_pages_from_single_cpu(struct page_collection *pc)
 829 {
 830         struct trace_cpu_data *tcd;
 831         int i, j;
 832
 833         tcd_for_each(tcd, i, j) {
 834                 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 835                 tcd->tcd_cur_pages = 0;
 836         }
 837 }
 838
 839 static void
 840 collect_pages_on_all_cpus(struct page_collection *pc)
 841 {
 842         struct trace_cpu_data *tcd;
 843         int i, cpu;
 844
 845         spin_lock(&pc->pc_lock);
 846         for_each_possible_cpu(cpu) {
 847                 tcd_for_each_type_lock(tcd, i, cpu) {
 848                         list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 849                         tcd->tcd_cur_pages = 0;
 850                 }
 851         }
 852         spin_unlock(&pc->pc_lock);
 853 }
 854
 855 static void
 856 collect_pages(dumplog_priv_t *dp, struct page_collection *pc)
 857 {
 858         INIT_LIST_HEAD(&pc->pc_pages);
 859
 860         if (spl_panic_in_progress || dp->dp_flags & DL_SINGLE_CPU)
 861                 collect_pages_from_single_cpu(pc);
 862         else
 863                 collect_pages_on_all_cpus(pc);
 864 }
 865
 866 static void
 867 put_pages_back_on_all_cpus(struct page_collection *pc)
 868 {
 869         struct trace_cpu_data *tcd;
 870         struct list_head *cur_head;
 871         struct trace_page *tage;
 872         struct trace_page *tmp;
 873         int i, cpu;
 874
 875         spin_lock(&pc->pc_lock);
 876
 877         for_each_possible_cpu(cpu) {
 878                 tcd_for_each_type_lock(tcd, i, cpu) {
 879                         cur_head = tcd->tcd_pages.next;
 880
 881                         list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
 882                                                  linkage) {
 883
 884                                 __ASSERT_TAGE_INVARIANT(tage);
 885
 886                                 if (tage->cpu != cpu || tage->type != i)
 887                                         continue;
 888
 889                                 tage_to_tail(tage, cur_head);
 890                                 tcd->tcd_cur_pages++;
 891                         }
 892                 }
 893         }
 894
 895         spin_unlock(&pc->pc_lock);
 896 }
 897
 898 static void
 899 put_pages_back(struct page_collection *pc)
 900 {
 901         if (!spl_panic_in_progress)
 902                 put_pages_back_on_all_cpus(pc);
 903 }
 904
 905 static struct file *
 906 trace_filp_open (const char *name, int flags, int mode, int *err)
 907 {
 908         struct file *filp = NULL;
 909         int rc;
 910
 911         filp = filp_open(name, flags, mode);
 912         if (IS_ERR(filp)) {
 913                 rc = PTR_ERR(filp);
 914                 printk(KERN_ERR "SPL: Can't open %s file: %d\n", name, rc);
 915                 if (err)
 916                         *err = rc;
 917                 filp = NULL;
 918         }
 919         return filp;
 920 }
 921
 922 #define trace_filp_write(fp, b, s, p)  (fp)->f_op->write((fp), (b), (s), p)
 923 #define trace_filp_fsync(fp)           (fp)->f_op->fsync((fp),(fp)->f_dentry,1)
 924 #define trace_filp_close(f)            filp_close(f, NULL)
 925 #define trace_filp_poff(f)             (&(f)->f_pos)
 926
 927 static int
 928 spl_debug_dump_all_pages(dumplog_priv_t *dp, char *filename)
 929 {
 930         struct page_collection pc;
 931         struct file *filp;
 932         struct trace_page *tage;
 933         struct trace_page *tmp;
 934         mm_segment_t oldfs;
 935         int rc = 0;
 936
 937         down_write(&trace_sem);
 938
 939         filp = trace_filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE,
 940                                0600, &rc);
 941         if (filp == NULL) {
 942                 if (rc != -EEXIST)
 943                         printk(KERN_ERR "SPL: Can't open %s for dump: %d\n",
 944                                filename, rc);
 945                 goto out;
 946         }
 947
 948         spin_lock_init(&pc.pc_lock);
 949         collect_pages(dp, &pc);
 950         if (list_empty(&pc.pc_pages)) {
 951                 rc = 0;
 952                 goto close;
 953         }
 954
 955         oldfs = get_fs();
 956         set_fs(get_ds());
 957
 958         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 959                 __ASSERT_TAGE_INVARIANT(tage);
 960
 961                 rc = trace_filp_write(filp, page_address(tage->page),
 962                                       tage->used, trace_filp_poff(filp));
 963                 if (rc != (int)tage->used) {
 964                         printk(KERN_WARNING "SPL: Wanted to write %u "
 965                                "but wrote %d\n", tage->used, rc);
 966                         put_pages_back(&pc);
 967                         __ASSERT(list_empty(&pc.pc_pages));
 968                         break;
 969                 }
 970                 list_del(&tage->linkage);
 971                 tage_free(tage);
 972         }
 973
 974         set_fs(oldfs);
 975
 976         rc = trace_filp_fsync(filp);
 977         if (rc)
 978                 printk(KERN_ERR "SPL: Unable to sync: %d\n", rc);
 979  close:
 980         trace_filp_close(filp);
 981  out:
 982         up_write(&trace_sem);
 983
 984         return rc;
 985 }
 986
 987 static void
 988 spl_debug_flush_pages(void)
 989 {
 990         dumplog_priv_t dp;
 991         struct page_collection pc;
 992         struct trace_page *tage;
 993         struct trace_page *tmp;
 994
 995         spin_lock_init(&pc.pc_lock);
 996         init_waitqueue_head(&dp.dp_waitq);
 997         dp.dp_pid = current->pid;
 998         dp.dp_flags = 0;
 999         atomic_set(&dp.dp_done, 0);
1000
1001         collect_pages(&dp, &pc);
1002         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
1003                 __ASSERT_TAGE_INVARIANT(tage);
1004                 list_del(&tage->linkage);
1005                 tage_free(tage);
1006         }
1007 }
1008
1009 unsigned long
1010 spl_debug_set_mask(unsigned long mask) {
1011         spl_debug_mask = mask;
1012         return 0;
1013 }
1014 EXPORT_SYMBOL(spl_debug_set_mask);
1015
1016 unsigned long
1017 spl_debug_get_mask(void) {
1018         return spl_debug_mask;
1019 }
1020 EXPORT_SYMBOL(spl_debug_get_mask);
1021
1022 unsigned long
1023 spl_debug_set_subsys(unsigned long subsys) {
1024         spl_debug_subsys = subsys;
1025         return 0;
1026 }
1027 EXPORT_SYMBOL(spl_debug_set_subsys);
1028
1029 unsigned long
1030 spl_debug_get_subsys(void) {
1031         return spl_debug_subsys;
1032 }
1033 EXPORT_SYMBOL(spl_debug_get_subsys);
1034
1035 int
1036 spl_debug_set_mb(int mb)
1037 {
1038         int i, j, pages;
1039         int limit = trace_max_debug_mb();
1040         struct trace_cpu_data *tcd;
1041
1042         if (mb < num_possible_cpus()) {
1043                 printk(KERN_ERR "SPL: Refusing to set debug buffer size to "
1044                        "%dMB - lower limit is %d\n", mb, num_possible_cpus());
1045                 return -EINVAL;
1046         }
1047
1048         if (mb > limit) {
1049                 printk(KERN_ERR "SPL: Refusing to set debug buffer size to "
1050                        "%dMB - upper limit is %d\n", mb, limit);
1051                 return -EINVAL;
1052         }
1053
1054         mb /= num_possible_cpus();
1055         pages = mb << (20 - PAGE_SHIFT);
1056
1057         down_write(&trace_sem);
1058
1059         tcd_for_each(tcd, i, j)
1060                 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
1061
1062         up_write(&trace_sem);
1063
1064         return 0;
1065 }
1066 EXPORT_SYMBOL(spl_debug_set_mb);
1067
1068 int
1069 spl_debug_get_mb(void)
1070 {
1071         int i, j;
1072         struct trace_cpu_data *tcd;
1073         int total_pages = 0;
1074
1075         down_read(&trace_sem);
1076
1077         tcd_for_each(tcd, i, j)
1078                 total_pages += tcd->tcd_max_pages;
1079
1080         up_read(&trace_sem);
1081
1082         return (total_pages >> (20 - PAGE_SHIFT)) + 1;
1083 }
1084 EXPORT_SYMBOL(spl_debug_get_mb);
1085
1086 void spl_debug_dumpstack(struct task_struct *tsk)
1087 {
1088         extern void show_task(struct task_struct *);
1089
1090         if (tsk == NULL)
1091                 tsk = current;
1092
1093         printk("SPL: Showing stack for process %d\n", tsk->pid);
1094         dump_stack();
1095 }
1096 EXPORT_SYMBOL(spl_debug_dumpstack);
1097
1098 void spl_debug_bug(char *file, const char *func, const int line, int flags)
1099 {
1100         spl_debug_catastrophe = 1;
1101         spl_debug_msg(NULL, 0, D_EMERG, file, func, line, "SBUG\n");
1102
1103         if (in_interrupt()) {
1104                 panic("SBUG in interrupt.\n");
1105                 /* not reached */
1106         }
1107
1108         if (in_atomic() || irqs_disabled())
1109                 flags |= DL_NOTHREAD;
1110
1111         /* Ensure all debug pages and dumped by current cpu */
1112          if (spl_debug_panic_on_bug)
1113                 spl_panic_in_progress = 1;
1114
1115         spl_debug_dumpstack(NULL);
1116         spl_debug_dumplog(flags);
1117
1118         if (spl_debug_panic_on_bug)
1119                 panic("SBUG");
1120
1121         set_task_state(current, TASK_UNINTERRUPTIBLE);
1122         while (1)
1123                 schedule();
1124 }
1125 EXPORT_SYMBOL(spl_debug_bug);
1126
1127 int
1128 spl_debug_clear_buffer(void)
1129 {
1130         spl_debug_flush_pages();
1131         return 0;
1132 }
1133 EXPORT_SYMBOL(spl_debug_clear_buffer);
1134
1135 int
1136 spl_debug_mark_buffer(char *text)
1137 {
1138         CDEBUG(D_WARNING, "*************************************\n");
1139         CDEBUG(D_WARNING, "DEBUG MARKER: %s\n", text);
1140         CDEBUG(D_WARNING, "*************************************\n");
1141
1142         return 0;
1143 }
1144 EXPORT_SYMBOL(spl_debug_mark_buffer);
1145
1146 static int
1147 trace_init(int max_pages)
1148 {
1149         struct trace_cpu_data *tcd;
1150         int i, j;
1151
1152         init_rwsem(&trace_sem);
1153
1154         /* initialize trace_data */
1155         memset(trace_data, 0, sizeof(trace_data));
1156         for (i = 0; i < TCD_TYPE_MAX; i++) {
1157                 trace_data[i] = kmalloc(sizeof(union trace_data_union) *
1158                                         NR_CPUS, GFP_KERNEL);
1159                 if (trace_data[i] == NULL)
1160                         goto out;
1161         }
1162
1163         tcd_for_each(tcd, i, j) {
1164                 spin_lock_init(&tcd->tcd_lock);
1165                 tcd->tcd_pages_factor = pages_factor[i];
1166                 tcd->tcd_type = i;
1167                 tcd->tcd_cpu = j;
1168                 INIT_LIST_HEAD(&tcd->tcd_pages);
1169                 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1170                 tcd->tcd_cur_pages = 0;
1171                 tcd->tcd_cur_stock_pages = 0;
1172                 tcd->tcd_max_pages = (max_pages * pages_factor[i]) / 100;
1173                 tcd->tcd_shutting_down = 0;
1174         }
1175
1176         for (i = 0; i < num_possible_cpus(); i++) {
1177                 for (j = 0; j < 3; j++) {
1178                         trace_console_buffers[i][j] =
1179                                 kmalloc(TRACE_CONSOLE_BUFFER_SIZE,
1180                                         GFP_KERNEL);
1181
1182                         if (trace_console_buffers[i][j] == NULL)
1183                                 goto out;
1184                 }
1185        }
1186
1187         return 0;
1188 out:
1189         trace_fini();
1190         printk(KERN_ERR "SPL: Insufficient memory for debug logs\n");
1191         return -ENOMEM;
1192 }
1193
1194 int
1195 debug_init(void)
1196 {
1197         int rc, max = spl_debug_mb;
1198
1199         spl_console_max_delay = SPL_DEFAULT_MAX_DELAY;
1200         spl_console_min_delay = SPL_DEFAULT_MIN_DELAY;
1201
1202         /* If spl_debug_mb is set to an invalid value or uninitialized
1203          * then just make the total buffers smp_num_cpus TCD_MAX_PAGES */
1204         if (max > (num_physpages >> (20 - 2 - PAGE_SHIFT)) / 5 ||
1205             max >= 512 || max < 0) {
1206                 max = TCD_MAX_PAGES;
1207         } else {
1208                 max = (max / num_online_cpus()) << (20 - PAGE_SHIFT);
1209         }
1210
1211         rc = trace_init(max);
1212         if (rc)
1213                 return rc;
1214
1215         return rc;
1216 }
1217
1218 static void
1219 trace_cleanup_on_all_cpus(void)
1220 {
1221         struct trace_cpu_data *tcd;
1222         struct trace_page *tage;
1223         struct trace_page *tmp;
1224         int i, cpu;
1225
1226         for_each_possible_cpu(cpu) {
1227                 tcd_for_each_type_lock(tcd, i, cpu) {
1228                         tcd->tcd_shutting_down = 1;
1229
1230                         list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
1231                                                  linkage) {
1232                                 __ASSERT_TAGE_INVARIANT(tage);
1233
1234                                 list_del(&tage->linkage);
1235                                 tage_free(tage);
1236                         }
1237                         tcd->tcd_cur_pages = 0;
1238                 }
1239         }
1240 }
1241
1242 static void
1243 trace_fini(void)
1244 {
1245         int i, j;
1246
1247         trace_cleanup_on_all_cpus();
1248
1249         for (i = 0; i < num_possible_cpus(); i++) {
1250                 for (j = 0; j < 3; j++) {
1251                         if (trace_console_buffers[i][j] != NULL) {
1252                                 kfree(trace_console_buffers[i][j]);
1253                                 trace_console_buffers[i][j] = NULL;
1254                         }
1255                 }
1256         }
1257
1258         for (i = 0; i < TCD_TYPE_MAX && trace_data[i] != NULL; i++) {
1259                 kfree(trace_data[i]);
1260                 trace_data[i] = NULL;
1261         }
1262 }
1263
1264 void
1265 debug_fini(void)
1266 {
1267         trace_fini();
1268 }