libcfs/libcfs/tracefile.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * libcfs/libcfs/tracefile.c
  37  *
  38  * Author: Zach Brown <zab@clusterfs.com>
  39  * Author: Phil Schwan <phil@clusterfs.com>
  40  */
  41
  42
  43 #define DEBUG_SUBSYSTEM S_LNET
  44 #define LUSTRE_TRACEFILE_PRIVATE
  45 #include "tracefile.h"
  46
  47 #include <libcfs/libcfs.h>
  48
  49 /* XXX move things up to the top, comment */
  50 union trace_data_union (*trace_data[TCD_MAX_TYPES])[NR_CPUS] __cacheline_aligned;
  51
  52 char tracefile[TRACEFILE_NAME_SIZE];
  53 long long tracefile_size = TRACEFILE_SIZE;
  54 static struct tracefiled_ctl trace_tctl;
  55 struct semaphore trace_thread_sem;
  56 static int thread_running = 0;
  57
  58 atomic_t tage_allocated = ATOMIC_INIT(0);
  59
  60 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
  61                                          struct trace_cpu_data *tcd);
  62
  63 static inline struct trace_page *tage_from_list(struct list_head *list)
  64 {
  65         return list_entry(list, struct trace_page, linkage);
  66 }
  67
  68 static struct trace_page *tage_alloc(int gfp)
  69 {
  70         cfs_page_t        *page;
  71         struct trace_page *tage;
  72
  73         /*
  74          * Don't spam console with allocation failures: they will be reported
  75          * by upper layer anyway.
  76          */
  77         gfp |= CFS_ALLOC_NOWARN;
  78         page = cfs_alloc_page(gfp);
  79         if (page == NULL)
  80                 return NULL;
  81
  82         tage = cfs_alloc(sizeof(*tage), gfp);
  83         if (tage == NULL) {
  84                 cfs_free_page(page);
  85                 return NULL;
  86         }
  87
  88         tage->page = page;
  89         atomic_inc(&tage_allocated);
  90         return tage;
  91 }
  92
  93 static void tage_free(struct trace_page *tage)
  94 {
  95         __LASSERT(tage != NULL);
  96         __LASSERT(tage->page != NULL);
  97
  98         cfs_free_page(tage->page);
  99         cfs_free(tage);
 100         atomic_dec(&tage_allocated);
 101 }
 102
 103 static void tage_to_tail(struct trace_page *tage, struct list_head *queue)
 104 {
 105         __LASSERT(tage != NULL);
 106         __LASSERT(queue != NULL);
 107
 108         list_move_tail(&tage->linkage, queue);
 109 }
 110
 111 int trace_refill_stock(struct trace_cpu_data *tcd, int gfp,
 112                        struct list_head *stock)
 113 {
 114         int i;
 115
 116         /*
 117          * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
 118          * from here: this will lead to infinite recursion.
 119          */
 120
 121         for (i = 0; i + tcd->tcd_cur_stock_pages < TCD_STOCK_PAGES ; ++ i) {
 122                 struct trace_page *tage;
 123
 124                 tage = tage_alloc(gfp);
 125                 if (tage == NULL)
 126                         break;
 127                 list_add_tail(&tage->linkage, stock);
 128         }
 129         return i;
 130 }
 131
 132 /* return a page that has 'len' bytes left at the end */
 133 static struct trace_page *trace_get_tage_try(struct trace_cpu_data *tcd,
 134                                              unsigned long len)
 135 {
 136         struct trace_page *tage;
 137
 138         if (tcd->tcd_cur_pages > 0) {
 139                 __LASSERT(!list_empty(&tcd->tcd_pages));
 140                 tage = tage_from_list(tcd->tcd_pages.prev);
 141                 if (tage->used + len <= CFS_PAGE_SIZE)
 142                         return tage;
 143         }
 144
 145         if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
 146                 if (tcd->tcd_cur_stock_pages > 0) {
 147                         tage = tage_from_list(tcd->tcd_stock_pages.prev);
 148                         -- tcd->tcd_cur_stock_pages;
 149                         list_del_init(&tage->linkage);
 150                 } else {
 151                         tage = tage_alloc(CFS_ALLOC_ATOMIC);
 152                         if (tage == NULL) {
 153                                 if (printk_ratelimit())
 154                                         printk(KERN_WARNING
 155                                                "cannot allocate a tage (%ld)\n",
 156                                        tcd->tcd_cur_pages);
 157                                 return NULL;
 158                         }
 159                 }
 160
 161                 tage->used = 0;
 162                 tage->cpu = smp_processor_id();
 163                 tage->type = tcd->tcd_type;
 164                 list_add_tail(&tage->linkage, &tcd->tcd_pages);
 165                 tcd->tcd_cur_pages++;
 166
 167                 if (tcd->tcd_cur_pages > 8 && thread_running) {
 168                         struct tracefiled_ctl *tctl = &trace_tctl;
 169                         /*
 170                          * wake up tracefiled to process some pages.
 171                          */
 172                         cfs_waitq_signal(&tctl->tctl_waitq);
 173                 }
 174                 return tage;
 175         }
 176         return NULL;
 177 }
 178
 179 static void tcd_shrink(struct trace_cpu_data *tcd)
 180 {
 181         int pgcount = tcd->tcd_cur_pages / 10;
 182         struct page_collection pc;
 183         struct trace_page *tage;
 184         struct trace_page *tmp;
 185
 186         /*
 187          * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
 188          * from here: this will lead to infinite recursion.
 189          */
 190
 191         if (printk_ratelimit())
 192                 printk(KERN_WARNING "debug daemon buffer overflowed; "
 193                        "discarding 10%% of pages (%d of %ld)\n",
 194                        pgcount + 1, tcd->tcd_cur_pages);
 195
 196         CFS_INIT_LIST_HEAD(&pc.pc_pages);
 197         spin_lock_init(&pc.pc_lock);
 198
 199         cfs_list_for_each_entry_safe_typed(tage, tmp, &tcd->tcd_pages,
 200                                            struct trace_page, linkage) {
 201                 if (pgcount-- == 0)
 202                         break;
 203
 204                 list_move_tail(&tage->linkage, &pc.pc_pages);
 205                 tcd->tcd_cur_pages--;
 206         }
 207         put_pages_on_tcd_daemon_list(&pc, tcd);
 208 }
 209
 210 /* return a page that has 'len' bytes left at the end */
 211 static struct trace_page *trace_get_tage(struct trace_cpu_data *tcd,
 212                                          unsigned long len)
 213 {
 214         struct trace_page *tage;
 215
 216         /*
 217          * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
 218          * from here: this will lead to infinite recursion.
 219          */
 220
 221         if (len > CFS_PAGE_SIZE) {
 222                 printk(KERN_ERR
 223                        "cowardly refusing to write %lu bytes in a page\n", len);
 224                 return NULL;
 225         }
 226
 227         tage = trace_get_tage_try(tcd, len);
 228         if (tage != NULL)
 229                 return tage;
 230         if (thread_running)
 231                 tcd_shrink(tcd);
 232         if (tcd->tcd_cur_pages > 0) {
 233                 tage = tage_from_list(tcd->tcd_pages.next);
 234                 tage->used = 0;
 235                 tage_to_tail(tage, &tcd->tcd_pages);
 236         }
 237         return tage;
 238 }
 239
 240 int libcfs_debug_vmsg2(cfs_debug_limit_state_t *cdls, int subsys, int mask,
 241                        const char *file, const char *fn, const int line,
 242                        const char *format1, va_list args,
 243                        const char *format2, ...)
 244 {
 245         struct trace_cpu_data   *tcd = NULL;
 246         struct ptldebug_header   header;
 247         struct trace_page       *tage;
 248         /* string_buf is used only if tcd != NULL, and is always set then */
 249         char                    *string_buf = NULL;
 250         char                    *debug_buf;
 251         int                      known_size;
 252         int                      needed = 85; /* average message length */
 253         int                      max_nob;
 254         va_list                  ap;
 255         int                      depth;
 256         int                      i;
 257         int                      remain;
 258
 259         if (strchr(file, '/'))
 260                 file = strrchr(file, '/') + 1;
 261
 262
 263         set_ptldebug_header(&header, subsys, mask, line, CDEBUG_STACK());
 264
 265         tcd = trace_get_tcd();
 266         if (tcd == NULL)                /* arch may not log in IRQ context */
 267                 goto console;
 268
 269         if (tcd->tcd_shutting_down) {
 270                 trace_put_tcd(tcd);
 271                 tcd = NULL;
 272                 goto console;
 273         }
 274
 275         depth = __current_nesting_level();
 276         known_size = strlen(file) + 1 + depth;
 277         if (fn)
 278                 known_size += strlen(fn) + 1;
 279
 280         if (libcfs_debug_binary)
 281                 known_size += sizeof(header);
 282
 283         /*/
 284          * '2' used because vsnprintf return real size required for output
 285          * _without_ terminating NULL.
 286          * if needed is to small for this format.
 287          */
 288         for (i = 0; i < 2; i++) {
 289                 tage = trace_get_tage(tcd, needed + known_size + 1);
 290                 if (tage == NULL) {
 291                         if (needed + known_size > CFS_PAGE_SIZE)
 292                                 mask |= D_ERROR;
 293
 294                         trace_put_tcd(tcd);
 295                         tcd = NULL;
 296                         goto console;
 297                 }
 298
 299                 string_buf = (char *)cfs_page_address(tage->page) +
 300                                         tage->used + known_size;
 301
 302                 max_nob = CFS_PAGE_SIZE - tage->used - known_size;
 303                 if (max_nob <= 0) {
 304                         printk(KERN_EMERG "negative max_nob: %i\n", max_nob);
 305                         mask |= D_ERROR;
 306                         trace_put_tcd(tcd);
 307                         tcd = NULL;
 308                         goto console;
 309                 }
 310
 311                 needed = 0;
 312                 if (format1) {
 313                         va_copy(ap, args);
 314                         needed = vsnprintf(string_buf, max_nob, format1, ap);
 315                         va_end(ap);
 316                 }
 317
 318                 if (format2) {
 319                         remain = max_nob - needed;
 320                         if (remain < 0)
 321                                 remain = 0;
 322
 323                         va_start(ap, format2);
 324                         needed += vsnprintf(string_buf + needed, remain,
 325                                             format2, ap);
 326                         va_end(ap);
 327                 }
 328
 329                 if (needed < max_nob) /* well. printing ok.. */
 330                         break;
 331         }
 332
 333         if (*(string_buf+needed-1) != '\n')
 334                 printk(KERN_INFO "format at %s:%d:%s doesn't end in newline\n",
 335                        file, line, fn);
 336
 337         header.ph_len = known_size + needed;
 338         debug_buf = (char *)cfs_page_address(tage->page) + tage->used;
 339
 340         if (libcfs_debug_binary) {
 341                 memcpy(debug_buf, &header, sizeof(header));
 342                 tage->used += sizeof(header);
 343                 debug_buf += sizeof(header);
 344         }
 345
 346         /* indent message according to the nesting level */
 347         while (depth-- > 0) {
 348                 *(debug_buf++) = '.';
 349                 ++ tage->used;
 350         }
 351
 352         strcpy(debug_buf, file);
 353         tage->used += strlen(file) + 1;
 354         debug_buf += strlen(file) + 1;
 355
 356         if (fn) {
 357                 strcpy(debug_buf, fn);
 358                 tage->used += strlen(fn) + 1;
 359                 debug_buf += strlen(fn) + 1;
 360         }
 361
 362         __LASSERT(debug_buf == string_buf);
 363
 364         tage->used += needed;
 365         __LASSERT (tage->used <= CFS_PAGE_SIZE);
 366
 367 console:
 368         if ((mask & libcfs_printk) == 0) {
 369                 /* no console output requested */
 370                 if (tcd != NULL)
 371                         trace_put_tcd(tcd);
 372                 return 1;
 373         }
 374
 375         if (cdls != NULL) {
 376                 if (libcfs_console_ratelimit &&
 377                     cdls->cdls_next != 0 &&     /* not first time ever */
 378                     !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
 379                         /* skipping a console message */
 380                         cdls->cdls_count++;
 381                         if (tcd != NULL)
 382                                 trace_put_tcd(tcd);
 383                         return 1;
 384                 }
 385
 386                 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
 387                                                        libcfs_console_max_delay
 388                                                        + cfs_time_seconds(10))) {
 389                         /* last timeout was a long time ago */
 390                         cdls->cdls_delay /= libcfs_console_backoff * 4;
 391                 } else {
 392                         cdls->cdls_delay *= libcfs_console_backoff;
 393
 394                         if (cdls->cdls_delay < libcfs_console_min_delay)
 395                                 cdls->cdls_delay = libcfs_console_min_delay;
 396                         else if (cdls->cdls_delay > libcfs_console_max_delay)
 397                                 cdls->cdls_delay = libcfs_console_max_delay;
 398                 }
 399
 400                 /* ensure cdls_next is never zero after it's been seen */
 401                 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
 402         }
 403
 404         if (tcd != NULL) {
 405                 print_to_console(&header, mask, string_buf, needed, file, fn);
 406                 trace_put_tcd(tcd);
 407         } else {
 408                 string_buf = trace_get_console_buffer();
 409
 410                 needed = 0;
 411                 if (format1 != NULL) {
 412                         va_copy(ap, args);
 413                         needed = vsnprintf(string_buf, TRACE_CONSOLE_BUFFER_SIZE, format1, ap);
 414                         va_end(ap);
 415                 }
 416                 if (format2 != NULL) {
 417                         remain = TRACE_CONSOLE_BUFFER_SIZE - needed;
 418                         if (remain > 0) {
 419                                 va_start(ap, format2);
 420                                 needed += vsnprintf(string_buf+needed, remain, format2, ap);
 421                                 va_end(ap);
 422                         }
 423                 }
 424                 print_to_console(&header, mask,
 425                                  string_buf, needed, file, fn);
 426
 427                 trace_put_console_buffer(string_buf);
 428         }
 429
 430         if (cdls != NULL && cdls->cdls_count != 0) {
 431                 string_buf = trace_get_console_buffer();
 432
 433                 needed = snprintf(string_buf, TRACE_CONSOLE_BUFFER_SIZE,
 434                          "Skipped %d previous similar message%s\n",
 435                          cdls->cdls_count, (cdls->cdls_count > 1) ? "s" : "");
 436
 437                 print_to_console(&header, mask,
 438                                  string_buf, needed, file, fn);
 439
 440                 trace_put_console_buffer(string_buf);
 441                 cdls->cdls_count = 0;
 442         }
 443
 444         return 0;
 445 }
 446 EXPORT_SYMBOL(libcfs_debug_vmsg2);
 447
 448 void
 449 libcfs_assertion_failed(const char *expr, const char *file,
 450                         const char *func, const int line)
 451 {
 452         libcfs_debug_msg(NULL, 0, D_EMERG, file, func, line,
 453                          "ASSERTION(%s) failed\n", expr);
 454         /* cfs_enter_debugger(); */
 455         lbug_with_loc(file, func, line);
 456 }
 457 EXPORT_SYMBOL(libcfs_assertion_failed);
 458
 459 void
 460 trace_assertion_failed(const char *str,
 461                        const char *fn, const char *file, int line)
 462 {
 463         struct ptldebug_header hdr;
 464
 465         libcfs_panic_in_progress = 1;
 466         libcfs_catastrophe = 1;
 467         mb();
 468
 469         set_ptldebug_header(&hdr, DEBUG_SUBSYSTEM, D_EMERG, line,
 470                             CDEBUG_STACK());
 471
 472         print_to_console(&hdr, D_EMERG, str, strlen(str), file, fn);
 473
 474         LIBCFS_PANIC("Lustre debug assertion failure\n");
 475
 476         /* not reached */
 477 }
 478
 479 static void
 480 panic_collect_pages(struct page_collection *pc)
 481 {
 482         /* Do the collect_pages job on a single CPU: assumes that all other
 483          * CPUs have been stopped during a panic.  If this isn't true for some
 484          * arch, this will have to be implemented separately in each arch.  */
 485         int                    i;
 486         int                    j;
 487         struct trace_cpu_data *tcd;
 488
 489         CFS_INIT_LIST_HEAD(&pc->pc_pages);
 490
 491         tcd_for_each(tcd, i, j) {
 492                 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 493                 tcd->tcd_cur_pages = 0;
 494
 495                 if (pc->pc_want_daemon_pages) {
 496                         list_splice_init(&tcd->tcd_daemon_pages, &pc->pc_pages);
 497                         tcd->tcd_cur_daemon_pages = 0;
 498                 }
 499         }
 500 }
 501
 502 static void collect_pages_on_all_cpus(struct page_collection *pc)
 503 {
 504         struct trace_cpu_data *tcd;
 505         int i, cpu;
 506
 507         spin_lock(&pc->pc_lock);
 508         for_each_possible_cpu(cpu) {
 509                 tcd_for_each_type_lock(tcd, i, cpu) {
 510                         list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 511                         tcd->tcd_cur_pages = 0;
 512                         if (pc->pc_want_daemon_pages) {
 513                                 list_splice_init(&tcd->tcd_daemon_pages,
 514                                                  &pc->pc_pages);
 515                                 tcd->tcd_cur_daemon_pages = 0;
 516                         }
 517                 }
 518         }
 519         spin_unlock(&pc->pc_lock);
 520 }
 521
 522 static void collect_pages(struct page_collection *pc)
 523 {
 524         CFS_INIT_LIST_HEAD(&pc->pc_pages);
 525
 526         if (libcfs_panic_in_progress)
 527                 panic_collect_pages(pc);
 528         else
 529                 collect_pages_on_all_cpus(pc);
 530 }
 531
 532 static void put_pages_back_on_all_cpus(struct page_collection *pc)
 533 {
 534         struct trace_cpu_data *tcd;
 535         struct list_head *cur_head;
 536         struct trace_page *tage;
 537         struct trace_page *tmp;
 538         int i, cpu;
 539
 540         spin_lock(&pc->pc_lock);
 541         for_each_possible_cpu(cpu) {
 542                 tcd_for_each_type_lock(tcd, i, cpu) {
 543                         cur_head = tcd->tcd_pages.next;
 544
 545                         cfs_list_for_each_entry_safe_typed(tage, tmp,
 546                                                            &pc->pc_pages,
 547                                                            struct trace_page,
 548                                                            linkage) {
 549
 550                                 __LASSERT_TAGE_INVARIANT(tage);
 551
 552                                 if (tage->cpu != cpu || tage->type != i)
 553                                         continue;
 554
 555                                 tage_to_tail(tage, cur_head);
 556                                 tcd->tcd_cur_pages++;
 557                         }
 558                 }
 559         }
 560         spin_unlock(&pc->pc_lock);
 561 }
 562
 563 static void put_pages_back(struct page_collection *pc)
 564 {
 565         if (!libcfs_panic_in_progress)
 566                 put_pages_back_on_all_cpus(pc);
 567 }
 568
 569 /* Add pages to a per-cpu debug daemon ringbuffer.  This buffer makes sure that
 570  * we have a good amount of data at all times for dumping during an LBUG, even
 571  * if we have been steadily writing (and otherwise discarding) pages via the
 572  * debug daemon. */
 573 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
 574                                          struct trace_cpu_data *tcd)
 575 {
 576         struct trace_page *tage;
 577         struct trace_page *tmp;
 578
 579         spin_lock(&pc->pc_lock);
 580         cfs_list_for_each_entry_safe_typed(tage, tmp, &pc->pc_pages,
 581                                            struct trace_page, linkage) {
 582
 583                 __LASSERT_TAGE_INVARIANT(tage);
 584
 585                 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
 586                         continue;
 587
 588                 tage_to_tail(tage, &tcd->tcd_daemon_pages);
 589                 tcd->tcd_cur_daemon_pages++;
 590
 591                 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
 592                         struct trace_page *victim;
 593
 594                         __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
 595                         victim = tage_from_list(tcd->tcd_daemon_pages.next);
 596
 597                         __LASSERT_TAGE_INVARIANT(victim);
 598
 599                         list_del(&victim->linkage);
 600                         tage_free(victim);
 601                         tcd->tcd_cur_daemon_pages--;
 602                 }
 603         }
 604         spin_unlock(&pc->pc_lock);
 605 }
 606
 607 static void put_pages_on_daemon_list(struct page_collection *pc)
 608 {
 609         struct trace_cpu_data *tcd;
 610         int i, cpu;
 611
 612         for_each_possible_cpu(cpu) {
 613                 tcd_for_each_type_lock(tcd, i, cpu)
 614                         put_pages_on_tcd_daemon_list(pc, tcd);
 615         }
 616 }
 617
 618 void trace_debug_print(void)
 619 {
 620         struct page_collection pc;
 621         struct trace_page *tage;
 622         struct trace_page *tmp;
 623
 624         spin_lock_init(&pc.pc_lock);
 625
 626         pc.pc_want_daemon_pages = 1;
 627         collect_pages(&pc);
 628         cfs_list_for_each_entry_safe_typed(tage, tmp, &pc.pc_pages,
 629                                            struct trace_page, linkage) {
 630                 char *p, *file, *fn;
 631                 cfs_page_t *page;
 632
 633                 __LASSERT_TAGE_INVARIANT(tage);
 634
 635                 page = tage->page;
 636                 p = cfs_page_address(page);
 637                 while (p < ((char *)cfs_page_address(page) + tage->used)) {
 638                         struct ptldebug_header *hdr;
 639                         int len;
 640                         hdr = (void *)p;
 641                         p += sizeof(*hdr);
 642                         file = p;
 643                         p += strlen(file) + 1;
 644                         fn = p;
 645                         p += strlen(fn) + 1;
 646                         len = hdr->ph_len - (int)(p - (char *)hdr);
 647
 648                         print_to_console(hdr, D_EMERG, p, len, file, fn);
 649
 650                         p += len;
 651                 }
 652
 653                 list_del(&tage->linkage);
 654                 tage_free(tage);
 655         }
 656 }
 657
 658 int tracefile_dump_all_pages(char *filename)
 659 {
 660         struct page_collection pc;
 661         cfs_file_t *filp;
 662         struct trace_page *tage;
 663         struct trace_page *tmp;
 664         int rc;
 665
 666         CFS_DECL_MMSPACE;
 667
 668         tracefile_write_lock();
 669
 670         filp = cfs_filp_open(filename,
 671                              O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600, &rc);
 672         if (!filp) {
 673                 if (rc != -EEXIST)
 674                         printk(KERN_ERR "LustreError: can't open %s for dump: rc %d\n",
 675                                filename, rc);
 676                 goto out;
 677         }
 678
 679         spin_lock_init(&pc.pc_lock);
 680         pc.pc_want_daemon_pages = 1;
 681         collect_pages(&pc);
 682         if (list_empty(&pc.pc_pages)) {
 683                 rc = 0;
 684                 goto close;
 685         }
 686
 687         /* ok, for now, just write the pages.  in the future we'll be building
 688          * iobufs with the pages and calling generic_direct_IO */
 689         CFS_MMSPACE_OPEN;
 690         cfs_list_for_each_entry_safe_typed(tage, tmp, &pc.pc_pages,
 691                                            struct trace_page, linkage) {
 692
 693                 __LASSERT_TAGE_INVARIANT(tage);
 694
 695                 rc = cfs_filp_write(filp, cfs_page_address(tage->page),
 696                                     tage->used, cfs_filp_poff(filp));
 697                 if (rc != (int)tage->used) {
 698                         printk(KERN_WARNING "wanted to write %u but wrote "
 699                                "%d\n", tage->used, rc);
 700                         put_pages_back(&pc);
 701                         __LASSERT(list_empty(&pc.pc_pages));
 702                         break;
 703                 }
 704                 list_del(&tage->linkage);
 705                 tage_free(tage);
 706         }
 707         CFS_MMSPACE_CLOSE;
 708         rc = cfs_filp_fsync(filp);
 709         if (rc)
 710                 printk(KERN_ERR "sync returns %d\n", rc);
 711  close:
 712         cfs_filp_close(filp);
 713  out:
 714         tracefile_write_unlock();
 715         return rc;
 716 }
 717
 718 void trace_flush_pages(void)
 719 {
 720         struct page_collection pc;
 721         struct trace_page *tage;
 722         struct trace_page *tmp;
 723
 724         spin_lock_init(&pc.pc_lock);
 725
 726         pc.pc_want_daemon_pages = 1;
 727         collect_pages(&pc);
 728         cfs_list_for_each_entry_safe_typed(tage, tmp, &pc.pc_pages,
 729                                            struct trace_page, linkage) {
 730
 731                 __LASSERT_TAGE_INVARIANT(tage);
 732
 733                 list_del(&tage->linkage);
 734                 tage_free(tage);
 735         }
 736 }
 737
 738 int trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
 739                         const char *usr_buffer, int usr_buffer_nob)
 740 {
 741         int    nob;
 742
 743         if (usr_buffer_nob > knl_buffer_nob)
 744                 return -EOVERFLOW;
 745
 746         if (copy_from_user((void *)knl_buffer,
 747                            (void *)usr_buffer, usr_buffer_nob))
 748                 return -EFAULT;
 749
 750         nob = strnlen(knl_buffer, usr_buffer_nob);
 751         while (nob-- >= 0)                      /* strip trailing whitespace */
 752                 if (!isspace(knl_buffer[nob]))
 753                         break;
 754
 755         if (nob < 0)                            /* empty string */
 756                 return -EINVAL;
 757
 758         if (nob == knl_buffer_nob)              /* no space to terminate */
 759                 return -EOVERFLOW;
 760
 761         knl_buffer[nob + 1] = 0;                /* terminate */
 762         return 0;
 763 }
 764
 765 int trace_copyout_string(char *usr_buffer, int usr_buffer_nob,
 766                          const char *knl_buffer, char *append)
 767 {
 768         /* NB if 'append' != NULL, it's a single character to append to the
 769          * copied out string - usually "\n", for /proc entries and "" (i.e. a
 770          * terminating zero byte) for sysctl entries */
 771         int   nob = strlen(knl_buffer);
 772
 773         if (nob > usr_buffer_nob)
 774                 nob = usr_buffer_nob;
 775
 776         if (copy_to_user(usr_buffer, knl_buffer, nob))
 777                 return -EFAULT;
 778
 779         if (append != NULL && nob < usr_buffer_nob) {
 780                 if (copy_to_user(usr_buffer + nob, append, 1))
 781                         return -EFAULT;
 782
 783                 nob++;
 784         }
 785
 786         return nob;
 787 }
 788 EXPORT_SYMBOL(trace_copyout_string);
 789
 790 int trace_allocate_string_buffer(char **str, int nob)
 791 {
 792         if (nob > 2 * CFS_PAGE_SIZE)            /* string must be "sensible" */
 793                 return -EINVAL;
 794
 795         *str = cfs_alloc(nob, CFS_ALLOC_STD | CFS_ALLOC_ZERO);
 796         if (*str == NULL)
 797                 return -ENOMEM;
 798
 799         return 0;
 800 }
 801
 802 void trace_free_string_buffer(char *str, int nob)
 803 {
 804         cfs_free(str);
 805 }
 806
 807 int trace_dump_debug_buffer_usrstr(void *usr_str, int usr_str_nob)
 808 {
 809         char         *str;
 810         int           rc;
 811
 812         rc = trace_allocate_string_buffer(&str, usr_str_nob + 1);
 813         if (rc != 0)
 814                 return rc;
 815
 816         rc = trace_copyin_string(str, usr_str_nob + 1,
 817                                  usr_str, usr_str_nob);
 818         if (rc != 0)
 819                 goto out;
 820
 821 #if !defined(__WINNT__)
 822         if (str[0] != '/') {
 823                 rc = -EINVAL;
 824                 goto out;
 825         }
 826 #endif
 827         rc = tracefile_dump_all_pages(str);
 828 out:
 829         trace_free_string_buffer(str, usr_str_nob + 1);
 830         return rc;
 831 }
 832
 833 int trace_daemon_command(char *str)
 834 {
 835         int       rc = 0;
 836
 837         tracefile_write_lock();
 838
 839         if (strcmp(str, "stop") == 0) {
 840                 tracefile_write_unlock();
 841                 trace_stop_thread();
 842                 tracefile_write_lock();
 843                 memset(tracefile, 0, sizeof(tracefile));
 844
 845         } else if (strncmp(str, "size=", 5) == 0) {
 846                 tracefile_size = simple_strtoul(str + 5, NULL, 0);
 847                 if (tracefile_size < 10 || tracefile_size > 20480)
 848                         tracefile_size = TRACEFILE_SIZE;
 849                 else
 850                         tracefile_size <<= 20;
 851
 852         } else if (strlen(str) >= sizeof(tracefile)) {
 853                 rc = -ENAMETOOLONG;
 854 #ifndef __WINNT__
 855         } else if (str[0] != '/') {
 856                 rc = -EINVAL;
 857 #endif
 858         } else {
 859                 strcpy(tracefile, str);
 860
 861                 printk(KERN_INFO "Lustre: debug daemon will attempt to start writing "
 862                        "to %s (%lukB max)\n", tracefile,
 863                        (long)(tracefile_size >> 10));
 864
 865                 trace_start_thread();
 866         }
 867
 868         tracefile_write_unlock();
 869         return rc;
 870 }
 871
 872 int trace_daemon_command_usrstr(void *usr_str, int usr_str_nob)
 873 {
 874         char *str;
 875         int   rc;
 876
 877         rc = trace_allocate_string_buffer(&str, usr_str_nob + 1);
 878         if (rc != 0)
 879                 return rc;
 880
 881         rc = trace_copyin_string(str, usr_str_nob + 1,
 882                                  usr_str, usr_str_nob);
 883         if (rc == 0)
 884                 rc = trace_daemon_command(str);
 885
 886         trace_free_string_buffer(str, usr_str_nob + 1);
 887         return rc;
 888 }
 889
 890 int trace_set_debug_mb(int mb)
 891 {
 892         int i;
 893         int j;
 894         int pages;
 895         int limit = trace_max_debug_mb();
 896         struct trace_cpu_data *tcd;
 897
 898         if (mb < num_possible_cpus())
 899                 return -EINVAL;
 900
 901         if (mb > limit) {
 902                 printk(KERN_ERR "Lustre: Refusing to set debug buffer size to "
 903                        "%dMB - limit is %d\n", mb, limit);
 904                 return -EINVAL;
 905         }
 906
 907         mb /= num_possible_cpus();
 908         pages = mb << (20 - CFS_PAGE_SHIFT);
 909
 910         tracefile_write_lock();
 911
 912         tcd_for_each(tcd, i, j)
 913                 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
 914
 915         tracefile_write_unlock();
 916
 917         return 0;
 918 }
 919
 920 int trace_set_debug_mb_usrstr(void *usr_str, int usr_str_nob)
 921 {
 922         char     str[32];
 923         int      rc;
 924
 925         rc = trace_copyin_string(str, sizeof(str), usr_str, usr_str_nob);
 926         if (rc < 0)
 927                 return rc;
 928
 929         return trace_set_debug_mb(simple_strtoul(str, NULL, 0));
 930 }
 931
 932 int trace_get_debug_mb(void)
 933 {
 934         int i;
 935         int j;
 936         struct trace_cpu_data *tcd;
 937         int total_pages = 0;
 938
 939         tracefile_read_lock();
 940
 941         tcd_for_each(tcd, i, j)
 942                 total_pages += tcd->tcd_max_pages;
 943
 944         tracefile_read_unlock();
 945
 946         return (total_pages >> (20 - CFS_PAGE_SHIFT)) + 1;
 947 }
 948
 949 static int tracefiled(void *arg)
 950 {
 951         struct page_collection pc;
 952         struct tracefiled_ctl *tctl = arg;
 953         struct trace_page *tage;
 954         struct trace_page *tmp;
 955         struct ptldebug_header *hdr;
 956         cfs_file_t *filp;
 957         int last_loop = 0;
 958         int rc;
 959
 960         CFS_DECL_MMSPACE;
 961
 962         /* we're started late enough that we pick up init's fs context */
 963         /* this is so broken in uml?  what on earth is going on? */
 964         cfs_daemonize("ktracefiled");
 965
 966         spin_lock_init(&pc.pc_lock);
 967         complete(&tctl->tctl_start);
 968
 969         while (1) {
 970                 cfs_waitlink_t __wait;
 971
 972                 pc.pc_want_daemon_pages = 0;
 973                 collect_pages(&pc);
 974                 if (list_empty(&pc.pc_pages))
 975                         goto end_loop;
 976
 977                 filp = NULL;
 978                 tracefile_read_lock();
 979                 if (tracefile[0] != 0) {
 980                         filp = cfs_filp_open(tracefile,
 981                                              O_CREAT | O_RDWR | O_LARGEFILE,
 982                                              0600, &rc);
 983                         if (!(filp))
 984                                 printk(KERN_WARNING "couldn't open %s: %d\n",
 985                                        tracefile, rc);
 986                 }
 987                 tracefile_read_unlock();
 988                 if (filp == NULL) {
 989                         put_pages_on_daemon_list(&pc);
 990                         __LASSERT(list_empty(&pc.pc_pages));
 991                         goto end_loop;
 992                 }
 993
 994                 CFS_MMSPACE_OPEN;
 995
 996                 /* mark the first header, so we can sort in chunks */
 997                 tage = tage_from_list(pc.pc_pages.next);
 998                 __LASSERT_TAGE_INVARIANT(tage);
 999
1000                 hdr = cfs_page_address(tage->page);
1001                 hdr->ph_flags |= PH_FLAG_FIRST_RECORD;
1002
1003                 cfs_list_for_each_entry_safe_typed(tage, tmp, &pc.pc_pages,
1004                                                    struct trace_page, linkage) {
1005                         static loff_t f_pos;
1006
1007                         __LASSERT_TAGE_INVARIANT(tage);
1008
1009                         if (f_pos >= (off_t)tracefile_size)
1010                                 f_pos = 0;
1011                         else if (f_pos > (off_t)cfs_filp_size(filp))
1012                                 f_pos = cfs_filp_size(filp);
1013
1014                         rc = cfs_filp_write(filp, cfs_page_address(tage->page),
1015                                             tage->used, &f_pos);
1016                         if (rc != (int)tage->used) {
1017                                 printk(KERN_WARNING "wanted to write %u but "
1018                                        "wrote %d\n", tage->used, rc);
1019                                 put_pages_back(&pc);
1020                                 __LASSERT(list_empty(&pc.pc_pages));
1021                         }
1022                 }
1023                 CFS_MMSPACE_CLOSE;
1024
1025                 cfs_filp_close(filp);
1026                 put_pages_on_daemon_list(&pc);
1027                 if (!list_empty(&pc.pc_pages)) {
1028                         int i;
1029
1030                         printk(KERN_ALERT "Lustre: trace pages aren't empty\n");
1031                         printk(KERN_ERR "total cpus(%d): ", num_possible_cpus());
1032                         for (i = 0; i < num_possible_cpus(); i++)
1033                                 if (cpu_online(i))
1034                                         printk(KERN_ERR "%d(on) ", i);
1035                                 else
1036                                         printk(KERN_ERR "%d(off) ", i);
1037                         printk(KERN_ERR "\n");
1038
1039                         i = 0;
1040                         list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1041                                                  linkage)
1042                                 printk(KERN_ERR "page %d belongs to cpu %d\n",
1043                                        ++i, tage->cpu);
1044                         printk(KERN_ERR "There are %d pages unwritten\n", i);
1045                 }
1046                 __LASSERT(list_empty(&pc.pc_pages));
1047 end_loop:
1048                 if (atomic_read(&tctl->tctl_shutdown)) {
1049                         if (last_loop == 0) {
1050                                 last_loop = 1;
1051                                 continue;
1052                         } else {
1053                                 break;
1054                         }
1055                 }
1056                 cfs_waitlink_init(&__wait);
1057                 cfs_waitq_add(&tctl->tctl_waitq, &__wait);
1058                 set_current_state(TASK_INTERRUPTIBLE);
1059                 cfs_waitq_timedwait(&__wait, CFS_TASK_INTERRUPTIBLE,
1060                                     cfs_time_seconds(1));
1061                 cfs_waitq_del(&tctl->tctl_waitq, &__wait);
1062         }
1063         complete(&tctl->tctl_stop);
1064         return 0;
1065 }
1066
1067 int trace_start_thread(void)
1068 {
1069         struct tracefiled_ctl *tctl = &trace_tctl;
1070         int rc = 0;
1071
1072         mutex_down(&trace_thread_sem);
1073         if (thread_running)
1074                 goto out;
1075
1076         init_completion(&tctl->tctl_start);
1077         init_completion(&tctl->tctl_stop);
1078         cfs_waitq_init(&tctl->tctl_waitq);
1079         atomic_set(&tctl->tctl_shutdown, 0);
1080
1081         if (cfs_kernel_thread(tracefiled, tctl, 0) < 0) {
1082                 rc = -ECHILD;
1083                 goto out;
1084         }
1085
1086         wait_for_completion(&tctl->tctl_start);
1087         thread_running = 1;
1088 out:
1089         mutex_up(&trace_thread_sem);
1090         return rc;
1091 }
1092
1093 void trace_stop_thread(void)
1094 {
1095         struct tracefiled_ctl *tctl = &trace_tctl;
1096
1097         mutex_down(&trace_thread_sem);
1098         if (thread_running) {
1099                 printk(KERN_INFO "Lustre: shutting down debug daemon thread...\n");
1100                 atomic_set(&tctl->tctl_shutdown, 1);
1101                 wait_for_completion(&tctl->tctl_stop);
1102                 thread_running = 0;
1103         }
1104         mutex_up(&trace_thread_sem);
1105 }
1106
1107 int tracefile_init(int max_pages)
1108 {
1109         struct trace_cpu_data *tcd;
1110         int                    i;
1111         int                    j;
1112         int                    rc;
1113         int                    factor;
1114
1115         rc = tracefile_init_arch();
1116         if (rc != 0)
1117                 return rc;
1118
1119         tcd_for_each(tcd, i, j) {
1120                 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1121                 factor = tcd->tcd_pages_factor;
1122                 CFS_INIT_LIST_HEAD(&tcd->tcd_pages);
1123                 CFS_INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1124                 CFS_INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1125                 tcd->tcd_cur_pages = 0;
1126                 tcd->tcd_cur_stock_pages = 0;
1127                 tcd->tcd_cur_daemon_pages = 0;
1128                 tcd->tcd_max_pages = (max_pages * factor) / 100;
1129                 LASSERT(tcd->tcd_max_pages > 0);
1130                 tcd->tcd_shutting_down = 0;
1131         }
1132
1133         return 0;
1134 }
1135
1136 static void trace_cleanup_on_all_cpus(void)
1137 {
1138         struct trace_cpu_data *tcd;
1139         struct trace_page *tage;
1140         struct trace_page *tmp;
1141         int i, cpu;
1142
1143         for_each_possible_cpu(cpu) {
1144                 tcd_for_each_type_lock(tcd, i, cpu) {
1145                         tcd->tcd_shutting_down = 1;
1146
1147                         cfs_list_for_each_entry_safe_typed(tage, tmp,
1148                                                            &tcd->tcd_pages,
1149                                                            struct trace_page,
1150                                                            linkage) {
1151                                 __LASSERT_TAGE_INVARIANT(tage);
1152
1153                                 list_del(&tage->linkage);
1154                                 tage_free(tage);
1155                         }
1156
1157                         tcd->tcd_cur_pages = 0;
1158                 }
1159         }
1160 }
1161
1162 static void trace_cleanup(void)
1163 {
1164         struct page_collection pc;
1165
1166         CFS_INIT_LIST_HEAD(&pc.pc_pages);
1167         spin_lock_init(&pc.pc_lock);
1168
1169         trace_cleanup_on_all_cpus();
1170
1171         tracefile_fini_arch();
1172 }
1173
1174 void tracefile_exit(void)
1175 {
1176         trace_stop_thread();
1177         trace_cleanup();
1178 }