kernel/drivers/staging/lustre/lustre/libcfs/tracefile.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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2012, Intel Corporation.
  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 "../../include/linux/libcfs/libcfs.h"
  48
  49 /* XXX move things up to the top, comment */
  50 union cfs_trace_data_union (*cfs_trace_data[TCD_MAX_TYPES])[NR_CPUS] __cacheline_aligned;
  51
  52 char cfs_tracefile[TRACEFILE_NAME_SIZE];
  53 long long cfs_tracefile_size = CFS_TRACEFILE_SIZE;
  54 static struct tracefiled_ctl trace_tctl;
  55 struct mutex cfs_trace_thread_mutex;
  56 static int thread_running;
  57
  58 static atomic_t cfs_tage_allocated = ATOMIC_INIT(0);
  59
  60 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
  61                                          struct cfs_trace_cpu_data *tcd);
  62
  63 static inline struct cfs_trace_page *
  64 cfs_tage_from_list(struct list_head *list)
  65 {
  66         return list_entry(list, struct cfs_trace_page, linkage);
  67 }
  68
  69 static struct cfs_trace_page *cfs_tage_alloc(gfp_t gfp)
  70 {
  71         struct page         *page;
  72         struct cfs_trace_page *tage;
  73
  74         /* My caller is trying to free memory */
  75         if (!in_interrupt() && memory_pressure_get())
  76                 return NULL;
  77
  78         /*
  79          * Don't spam console with allocation failures: they will be reported
  80          * by upper layer anyway.
  81          */
  82         gfp |= __GFP_NOWARN;
  83         page = alloc_page(gfp);
  84         if (page == NULL)
  85                 return NULL;
  86
  87         tage = kmalloc(sizeof(*tage), gfp);
  88         if (tage == NULL) {
  89                 __free_page(page);
  90                 return NULL;
  91         }
  92
  93         tage->page = page;
  94         atomic_inc(&cfs_tage_allocated);
  95         return tage;
  96 }
  97
  98 static void cfs_tage_free(struct cfs_trace_page *tage)
  99 {
 100         __LASSERT(tage != NULL);
 101         __LASSERT(tage->page != NULL);
 102
 103         __free_page(tage->page);
 104         kfree(tage);
 105         atomic_dec(&cfs_tage_allocated);
 106 }
 107
 108 static void cfs_tage_to_tail(struct cfs_trace_page *tage,
 109                              struct list_head *queue)
 110 {
 111         __LASSERT(tage != NULL);
 112         __LASSERT(queue != NULL);
 113
 114         list_move_tail(&tage->linkage, queue);
 115 }
 116
 117 int cfs_trace_refill_stock(struct cfs_trace_cpu_data *tcd, gfp_t gfp,
 118                            struct list_head *stock)
 119 {
 120         int i;
 121
 122         /*
 123          * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
 124          * from here: this will lead to infinite recursion.
 125          */
 126
 127         for (i = 0; i + tcd->tcd_cur_stock_pages < TCD_STOCK_PAGES ; ++ i) {
 128                 struct cfs_trace_page *tage;
 129
 130                 tage = cfs_tage_alloc(gfp);
 131                 if (tage == NULL)
 132                         break;
 133                 list_add_tail(&tage->linkage, stock);
 134         }
 135         return i;
 136 }
 137
 138 /* return a page that has 'len' bytes left at the end */
 139 static struct cfs_trace_page *
 140 cfs_trace_get_tage_try(struct cfs_trace_cpu_data *tcd, unsigned long len)
 141 {
 142         struct cfs_trace_page *tage;
 143
 144         if (tcd->tcd_cur_pages > 0) {
 145                 __LASSERT(!list_empty(&tcd->tcd_pages));
 146                 tage = cfs_tage_from_list(tcd->tcd_pages.prev);
 147                 if (tage->used + len <= PAGE_CACHE_SIZE)
 148                         return tage;
 149         }
 150
 151         if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
 152                 if (tcd->tcd_cur_stock_pages > 0) {
 153                         tage = cfs_tage_from_list(tcd->tcd_stock_pages.prev);
 154                         --tcd->tcd_cur_stock_pages;
 155                         list_del_init(&tage->linkage);
 156                 } else {
 157                         tage = cfs_tage_alloc(GFP_ATOMIC);
 158                         if (unlikely(tage == NULL)) {
 159                                 if ((!memory_pressure_get() ||
 160                                      in_interrupt()) && printk_ratelimit())
 161                                         printk(KERN_WARNING
 162                                                "cannot allocate a tage (%ld)\n",
 163                                                tcd->tcd_cur_pages);
 164                                 return NULL;
 165                         }
 166                 }
 167
 168                 tage->used = 0;
 169                 tage->cpu = smp_processor_id();
 170                 tage->type = tcd->tcd_type;
 171                 list_add_tail(&tage->linkage, &tcd->tcd_pages);
 172                 tcd->tcd_cur_pages++;
 173
 174                 if (tcd->tcd_cur_pages > 8 && thread_running) {
 175                         struct tracefiled_ctl *tctl = &trace_tctl;
 176                         /*
 177                          * wake up tracefiled to process some pages.
 178                          */
 179                         wake_up(&tctl->tctl_waitq);
 180                 }
 181                 return tage;
 182         }
 183         return NULL;
 184 }
 185
 186 static void cfs_tcd_shrink(struct cfs_trace_cpu_data *tcd)
 187 {
 188         int pgcount = tcd->tcd_cur_pages / 10;
 189         struct page_collection pc;
 190         struct cfs_trace_page *tage;
 191         struct cfs_trace_page *tmp;
 192
 193         /*
 194          * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
 195          * from here: this will lead to infinite recursion.
 196          */
 197
 198         if (printk_ratelimit())
 199                 printk(KERN_WARNING "debug daemon buffer overflowed; discarding 10%% of pages (%d of %ld)\n",
 200                        pgcount + 1, tcd->tcd_cur_pages);
 201
 202         INIT_LIST_HEAD(&pc.pc_pages);
 203         spin_lock_init(&pc.pc_lock);
 204
 205         list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
 206                 if (pgcount-- == 0)
 207                         break;
 208
 209                 list_move_tail(&tage->linkage, &pc.pc_pages);
 210                 tcd->tcd_cur_pages--;
 211         }
 212         put_pages_on_tcd_daemon_list(&pc, tcd);
 213 }
 214
 215 /* return a page that has 'len' bytes left at the end */
 216 static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
 217                                                  unsigned long len)
 218 {
 219         struct cfs_trace_page *tage;
 220
 221         /*
 222          * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
 223          * from here: this will lead to infinite recursion.
 224          */
 225
 226         if (len > PAGE_CACHE_SIZE) {
 227                 pr_err("cowardly refusing to write %lu bytes in a page\n", len);
 228                 return NULL;
 229         }
 230
 231         tage = cfs_trace_get_tage_try(tcd, len);
 232         if (tage != NULL)
 233                 return tage;
 234         if (thread_running)
 235                 cfs_tcd_shrink(tcd);
 236         if (tcd->tcd_cur_pages > 0) {
 237                 tage = cfs_tage_from_list(tcd->tcd_pages.next);
 238                 tage->used = 0;
 239                 cfs_tage_to_tail(tage, &tcd->tcd_pages);
 240         }
 241         return tage;
 242 }
 243
 244 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
 245                      const char *format, ...)
 246 {
 247         va_list args;
 248         int     rc;
 249
 250         va_start(args, format);
 251         rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
 252         va_end(args);
 253
 254         return rc;
 255 }
 256 EXPORT_SYMBOL(libcfs_debug_msg);
 257
 258 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
 259                        const char *format1, va_list args,
 260                        const char *format2, ...)
 261 {
 262         struct cfs_trace_cpu_data *tcd = NULL;
 263         struct ptldebug_header     header = {0};
 264         struct cfs_trace_page     *tage;
 265         /* string_buf is used only if tcd != NULL, and is always set then */
 266         char                  *string_buf = NULL;
 267         char                  *debug_buf;
 268         int                     known_size;
 269         int                     needed = 85; /* average message length */
 270         int                     max_nob;
 271         va_list             ap;
 272         int                     depth;
 273         int                     i;
 274         int                     remain;
 275         int                     mask = msgdata->msg_mask;
 276         const char              *file = kbasename(msgdata->msg_file);
 277         struct cfs_debug_limit_state   *cdls = msgdata->msg_cdls;
 278
 279         tcd = cfs_trace_get_tcd();
 280
 281         /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
 282          * pins us to a particular CPU.  This avoids an smp_processor_id()
 283          * warning on Linux when debugging is enabled. */
 284         cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
 285
 286         if (tcd == NULL)                /* arch may not log in IRQ context */
 287                 goto console;
 288
 289         if (tcd->tcd_cur_pages == 0)
 290                 header.ph_flags |= PH_FLAG_FIRST_RECORD;
 291
 292         if (tcd->tcd_shutting_down) {
 293                 cfs_trace_put_tcd(tcd);
 294                 tcd = NULL;
 295                 goto console;
 296         }
 297
 298         depth = __current_nesting_level();
 299         known_size = strlen(file) + 1 + depth;
 300         if (msgdata->msg_fn)
 301                 known_size += strlen(msgdata->msg_fn) + 1;
 302
 303         if (libcfs_debug_binary)
 304                 known_size += sizeof(header);
 305
 306         /*/
 307          * '2' used because vsnprintf return real size required for output
 308          * _without_ terminating NULL.
 309          * if needed is to small for this format.
 310          */
 311         for (i = 0; i < 2; i++) {
 312                 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
 313                 if (tage == NULL) {
 314                         if (needed + known_size > PAGE_CACHE_SIZE)
 315                                 mask |= D_ERROR;
 316
 317                         cfs_trace_put_tcd(tcd);
 318                         tcd = NULL;
 319                         goto console;
 320                 }
 321
 322                 string_buf = (char *)page_address(tage->page) +
 323                                         tage->used + known_size;
 324
 325                 max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
 326                 if (max_nob <= 0) {
 327                         printk(KERN_EMERG "negative max_nob: %d\n",
 328                                max_nob);
 329                         mask |= D_ERROR;
 330                         cfs_trace_put_tcd(tcd);
 331                         tcd = NULL;
 332                         goto console;
 333                 }
 334
 335                 needed = 0;
 336                 if (format1) {
 337                         va_copy(ap, args);
 338                         needed = vsnprintf(string_buf, max_nob, format1, ap);
 339                         va_end(ap);
 340                 }
 341
 342                 if (format2) {
 343                         remain = max_nob - needed;
 344                         if (remain < 0)
 345                                 remain = 0;
 346
 347                         va_start(ap, format2);
 348                         needed += vsnprintf(string_buf + needed, remain,
 349                                             format2, ap);
 350                         va_end(ap);
 351                 }
 352
 353                 if (needed < max_nob) /* well. printing ok.. */
 354                         break;
 355         }
 356
 357         if (*(string_buf+needed-1) != '\n')
 358                 printk(KERN_INFO "format at %s:%d:%s doesn't end in newline\n",
 359                        file, msgdata->msg_line, msgdata->msg_fn);
 360
 361         header.ph_len = known_size + needed;
 362         debug_buf = (char *)page_address(tage->page) + tage->used;
 363
 364         if (libcfs_debug_binary) {
 365                 memcpy(debug_buf, &header, sizeof(header));
 366                 tage->used += sizeof(header);
 367                 debug_buf += sizeof(header);
 368         }
 369
 370         /* indent message according to the nesting level */
 371         while (depth-- > 0) {
 372                 *(debug_buf++) = '.';
 373                 ++ tage->used;
 374         }
 375
 376         strcpy(debug_buf, file);
 377         tage->used += strlen(file) + 1;
 378         debug_buf += strlen(file) + 1;
 379
 380         if (msgdata->msg_fn) {
 381                 strcpy(debug_buf, msgdata->msg_fn);
 382                 tage->used += strlen(msgdata->msg_fn) + 1;
 383                 debug_buf += strlen(msgdata->msg_fn) + 1;
 384         }
 385
 386         __LASSERT(debug_buf == string_buf);
 387
 388         tage->used += needed;
 389         __LASSERT (tage->used <= PAGE_CACHE_SIZE);
 390
 391 console:
 392         if ((mask & libcfs_printk) == 0) {
 393                 /* no console output requested */
 394                 if (tcd != NULL)
 395                         cfs_trace_put_tcd(tcd);
 396                 return 1;
 397         }
 398
 399         if (cdls != NULL) {
 400                 if (libcfs_console_ratelimit &&
 401                     cdls->cdls_next != 0 &&     /* not first time ever */
 402                     !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
 403                         /* skipping a console message */
 404                         cdls->cdls_count++;
 405                         if (tcd != NULL)
 406                                 cfs_trace_put_tcd(tcd);
 407                         return 1;
 408                 }
 409
 410                 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
 411                                                        libcfs_console_max_delay
 412                                                        + cfs_time_seconds(10))) {
 413                         /* last timeout was a long time ago */
 414                         cdls->cdls_delay /= libcfs_console_backoff * 4;
 415                 } else {
 416                         cdls->cdls_delay *= libcfs_console_backoff;
 417                 }
 418
 419                 if (cdls->cdls_delay < libcfs_console_min_delay)
 420                         cdls->cdls_delay = libcfs_console_min_delay;
 421                 else if (cdls->cdls_delay > libcfs_console_max_delay)
 422                         cdls->cdls_delay = libcfs_console_max_delay;
 423
 424                 /* ensure cdls_next is never zero after it's been seen */
 425                 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
 426         }
 427
 428         if (tcd != NULL) {
 429                 cfs_print_to_console(&header, mask, string_buf, needed, file,
 430                                      msgdata->msg_fn);
 431                 cfs_trace_put_tcd(tcd);
 432         } else {
 433                 string_buf = cfs_trace_get_console_buffer();
 434
 435                 needed = 0;
 436                 if (format1 != NULL) {
 437                         va_copy(ap, args);
 438                         needed = vsnprintf(string_buf,
 439                                            CFS_TRACE_CONSOLE_BUFFER_SIZE,
 440                                            format1, ap);
 441                         va_end(ap);
 442                 }
 443                 if (format2 != NULL) {
 444                         remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
 445                         if (remain > 0) {
 446                                 va_start(ap, format2);
 447                                 needed += vsnprintf(string_buf+needed, remain,
 448                                                     format2, ap);
 449                                 va_end(ap);
 450                         }
 451                 }
 452                 cfs_print_to_console(&header, mask,
 453                                      string_buf, needed, file, msgdata->msg_fn);
 454
 455                 cfs_trace_put_console_buffer(string_buf);
 456         }
 457
 458         if (cdls != NULL && cdls->cdls_count != 0) {
 459                 string_buf = cfs_trace_get_console_buffer();
 460
 461                 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
 462                                   "Skipped %d previous similar message%s\n",
 463                                   cdls->cdls_count,
 464                                   (cdls->cdls_count > 1) ? "s" : "");
 465
 466                 cfs_print_to_console(&header, mask,
 467                                      string_buf, needed, file, msgdata->msg_fn);
 468
 469                 cfs_trace_put_console_buffer(string_buf);
 470                 cdls->cdls_count = 0;
 471         }
 472
 473         return 0;
 474 }
 475 EXPORT_SYMBOL(libcfs_debug_vmsg2);
 476
 477 void
 478 cfs_trace_assertion_failed(const char *str,
 479                            struct libcfs_debug_msg_data *msgdata)
 480 {
 481         struct ptldebug_header hdr;
 482
 483         libcfs_panic_in_progress = 1;
 484         libcfs_catastrophe = 1;
 485         mb();
 486
 487         cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
 488
 489         cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
 490                              msgdata->msg_file, msgdata->msg_fn);
 491
 492         panic("Lustre debug assertion failure\n");
 493
 494         /* not reached */
 495 }
 496
 497 static void
 498 panic_collect_pages(struct page_collection *pc)
 499 {
 500         /* Do the collect_pages job on a single CPU: assumes that all other
 501          * CPUs have been stopped during a panic.  If this isn't true for some
 502          * arch, this will have to be implemented separately in each arch.  */
 503         int                     i;
 504         int                     j;
 505         struct cfs_trace_cpu_data *tcd;
 506
 507         INIT_LIST_HEAD(&pc->pc_pages);
 508
 509         cfs_tcd_for_each(tcd, i, j) {
 510                 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 511                 tcd->tcd_cur_pages = 0;
 512
 513                 if (pc->pc_want_daemon_pages) {
 514                         list_splice_init(&tcd->tcd_daemon_pages,
 515                                              &pc->pc_pages);
 516                         tcd->tcd_cur_daemon_pages = 0;
 517                 }
 518         }
 519 }
 520
 521 static void collect_pages_on_all_cpus(struct page_collection *pc)
 522 {
 523         struct cfs_trace_cpu_data *tcd;
 524         int i, cpu;
 525
 526         spin_lock(&pc->pc_lock);
 527         for_each_possible_cpu(cpu) {
 528                 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
 529                         list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 530                         tcd->tcd_cur_pages = 0;
 531                         if (pc->pc_want_daemon_pages) {
 532                                 list_splice_init(&tcd->tcd_daemon_pages,
 533                                                      &pc->pc_pages);
 534                                 tcd->tcd_cur_daemon_pages = 0;
 535                         }
 536                 }
 537         }
 538         spin_unlock(&pc->pc_lock);
 539 }
 540
 541 static void collect_pages(struct page_collection *pc)
 542 {
 543         INIT_LIST_HEAD(&pc->pc_pages);
 544
 545         if (libcfs_panic_in_progress)
 546                 panic_collect_pages(pc);
 547         else
 548                 collect_pages_on_all_cpus(pc);
 549 }
 550
 551 static void put_pages_back_on_all_cpus(struct page_collection *pc)
 552 {
 553         struct cfs_trace_cpu_data *tcd;
 554         struct list_head *cur_head;
 555         struct cfs_trace_page *tage;
 556         struct cfs_trace_page *tmp;
 557         int i, cpu;
 558
 559         spin_lock(&pc->pc_lock);
 560         for_each_possible_cpu(cpu) {
 561                 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
 562                         cur_head = tcd->tcd_pages.next;
 563
 564                         list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
 565                                                  linkage) {
 566
 567                                 __LASSERT_TAGE_INVARIANT(tage);
 568
 569                                 if (tage->cpu != cpu || tage->type != i)
 570                                         continue;
 571
 572                                 cfs_tage_to_tail(tage, cur_head);
 573                                 tcd->tcd_cur_pages++;
 574                         }
 575                 }
 576         }
 577         spin_unlock(&pc->pc_lock);
 578 }
 579
 580 static void put_pages_back(struct page_collection *pc)
 581 {
 582         if (!libcfs_panic_in_progress)
 583                 put_pages_back_on_all_cpus(pc);
 584 }
 585
 586 /* Add pages to a per-cpu debug daemon ringbuffer.  This buffer makes sure that
 587  * we have a good amount of data at all times for dumping during an LBUG, even
 588  * if we have been steadily writing (and otherwise discarding) pages via the
 589  * debug daemon. */
 590 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
 591                                          struct cfs_trace_cpu_data *tcd)
 592 {
 593         struct cfs_trace_page *tage;
 594         struct cfs_trace_page *tmp;
 595
 596         spin_lock(&pc->pc_lock);
 597         list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
 598
 599                 __LASSERT_TAGE_INVARIANT(tage);
 600
 601                 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
 602                         continue;
 603
 604                 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
 605                 tcd->tcd_cur_daemon_pages++;
 606
 607                 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
 608                         struct cfs_trace_page *victim;
 609
 610                         __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
 611                         victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
 612
 613                         __LASSERT_TAGE_INVARIANT(victim);
 614
 615                         list_del(&victim->linkage);
 616                         cfs_tage_free(victim);
 617                         tcd->tcd_cur_daemon_pages--;
 618                 }
 619         }
 620         spin_unlock(&pc->pc_lock);
 621 }
 622
 623 static void put_pages_on_daemon_list(struct page_collection *pc)
 624 {
 625         struct cfs_trace_cpu_data *tcd;
 626         int i, cpu;
 627
 628         for_each_possible_cpu(cpu) {
 629                 cfs_tcd_for_each_type_lock(tcd, i, cpu)
 630                         put_pages_on_tcd_daemon_list(pc, tcd);
 631         }
 632 }
 633
 634 void cfs_trace_debug_print(void)
 635 {
 636         struct page_collection pc;
 637         struct cfs_trace_page *tage;
 638         struct cfs_trace_page *tmp;
 639
 640         spin_lock_init(&pc.pc_lock);
 641
 642         pc.pc_want_daemon_pages = 1;
 643         collect_pages(&pc);
 644         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 645                 char *p, *file, *fn;
 646                 struct page *page;
 647
 648                 __LASSERT_TAGE_INVARIANT(tage);
 649
 650                 page = tage->page;
 651                 p = page_address(page);
 652                 while (p < ((char *)page_address(page) + tage->used)) {
 653                         struct ptldebug_header *hdr;
 654                         int len;
 655                         hdr = (void *)p;
 656                         p += sizeof(*hdr);
 657                         file = p;
 658                         p += strlen(file) + 1;
 659                         fn = p;
 660                         p += strlen(fn) + 1;
 661                         len = hdr->ph_len - (int)(p - (char *)hdr);
 662
 663                         cfs_print_to_console(hdr, D_EMERG, p, len, file, fn);
 664
 665                         p += len;
 666                 }
 667
 668                 list_del(&tage->linkage);
 669                 cfs_tage_free(tage);
 670         }
 671 }
 672
 673 int cfs_tracefile_dump_all_pages(char *filename)
 674 {
 675         struct page_collection  pc;
 676         struct file             *filp;
 677         struct cfs_trace_page   *tage;
 678         struct cfs_trace_page   *tmp;
 679         char                    *buf;
 680         int rc;
 681
 682         DECL_MMSPACE;
 683
 684         cfs_tracefile_write_lock();
 685
 686         filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
 687         if (IS_ERR(filp)) {
 688                 rc = PTR_ERR(filp);
 689                 filp = NULL;
 690                 pr_err("LustreError: can't open %s for dump: rc %d\n",
 691                         filename, rc);
 692                 goto out;
 693         }
 694
 695         spin_lock_init(&pc.pc_lock);
 696         pc.pc_want_daemon_pages = 1;
 697         collect_pages(&pc);
 698         if (list_empty(&pc.pc_pages)) {
 699                 rc = 0;
 700                 goto close;
 701         }
 702
 703         /* ok, for now, just write the pages.  in the future we'll be building
 704          * iobufs with the pages and calling generic_direct_IO */
 705         MMSPACE_OPEN;
 706         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 707
 708                 __LASSERT_TAGE_INVARIANT(tage);
 709
 710                 buf = kmap(tage->page);
 711                 rc = vfs_write(filp, (__force const char __user *)buf,
 712                                tage->used, &filp->f_pos);
 713                 kunmap(tage->page);
 714
 715                 if (rc != (int)tage->used) {
 716                         printk(KERN_WARNING "wanted to write %u but wrote %d\n",
 717                                tage->used, rc);
 718                         put_pages_back(&pc);
 719                         __LASSERT(list_empty(&pc.pc_pages));
 720                         break;
 721                 }
 722                 list_del(&tage->linkage);
 723                 cfs_tage_free(tage);
 724         }
 725         MMSPACE_CLOSE;
 726         rc = vfs_fsync(filp, 1);
 727         if (rc)
 728                 pr_err("sync returns %d\n", rc);
 729 close:
 730         filp_close(filp, NULL);
 731 out:
 732         cfs_tracefile_write_unlock();
 733         return rc;
 734 }
 735
 736 void cfs_trace_flush_pages(void)
 737 {
 738         struct page_collection pc;
 739         struct cfs_trace_page *tage;
 740         struct cfs_trace_page *tmp;
 741
 742         spin_lock_init(&pc.pc_lock);
 743
 744         pc.pc_want_daemon_pages = 1;
 745         collect_pages(&pc);
 746         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 747
 748                 __LASSERT_TAGE_INVARIANT(tage);
 749
 750                 list_del(&tage->linkage);
 751                 cfs_tage_free(tage);
 752         }
 753 }
 754
 755 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
 756                             const char __user *usr_buffer, int usr_buffer_nob)
 757 {
 758         int    nob;
 759
 760         if (usr_buffer_nob > knl_buffer_nob)
 761                 return -EOVERFLOW;
 762
 763         if (copy_from_user((void *)knl_buffer,
 764                            usr_buffer, usr_buffer_nob))
 765                 return -EFAULT;
 766
 767         nob = strnlen(knl_buffer, usr_buffer_nob);
 768         while (nob-- >= 0)                    /* strip trailing whitespace */
 769                 if (!isspace(knl_buffer[nob]))
 770                         break;
 771
 772         if (nob < 0)                        /* empty string */
 773                 return -EINVAL;
 774
 775         if (nob == knl_buffer_nob)            /* no space to terminate */
 776                 return -EOVERFLOW;
 777
 778         knl_buffer[nob + 1] = 0;                /* terminate */
 779         return 0;
 780 }
 781 EXPORT_SYMBOL(cfs_trace_copyin_string);
 782
 783 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
 784                              const char *knl_buffer, char *append)
 785 {
 786         /* NB if 'append' != NULL, it's a single character to append to the
 787          * copied out string - usually "\n", for /proc entries and "" (i.e. a
 788          * terminating zero byte) for sysctl entries */
 789         int   nob = strlen(knl_buffer);
 790
 791         if (nob > usr_buffer_nob)
 792                 nob = usr_buffer_nob;
 793
 794         if (copy_to_user(usr_buffer, knl_buffer, nob))
 795                 return -EFAULT;
 796
 797         if (append != NULL && nob < usr_buffer_nob) {
 798                 if (copy_to_user(usr_buffer + nob, append, 1))
 799                         return -EFAULT;
 800
 801                 nob++;
 802         }
 803
 804         return nob;
 805 }
 806 EXPORT_SYMBOL(cfs_trace_copyout_string);
 807
 808 int cfs_trace_allocate_string_buffer(char **str, int nob)
 809 {
 810         if (nob > 2 * PAGE_CACHE_SIZE)      /* string must be "sensible" */
 811                 return -EINVAL;
 812
 813         *str = kmalloc(nob, GFP_IOFS | __GFP_ZERO);
 814         if (*str == NULL)
 815                 return -ENOMEM;
 816
 817         return 0;
 818 }
 819
 820 void cfs_trace_free_string_buffer(char *str, int nob)
 821 {
 822         kfree(str);
 823 }
 824
 825 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
 826 {
 827         char     *str;
 828         int        rc;
 829
 830         rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
 831         if (rc != 0)
 832                 return rc;
 833
 834         rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
 835                                      usr_str, usr_str_nob);
 836         if (rc != 0)
 837                 goto out;
 838
 839         if (str[0] != '/') {
 840                 rc = -EINVAL;
 841                 goto out;
 842         }
 843         rc = cfs_tracefile_dump_all_pages(str);
 844 out:
 845         cfs_trace_free_string_buffer(str, usr_str_nob + 1);
 846         return rc;
 847 }
 848
 849 int cfs_trace_daemon_command(char *str)
 850 {
 851         int       rc = 0;
 852
 853         cfs_tracefile_write_lock();
 854
 855         if (strcmp(str, "stop") == 0) {
 856                 cfs_tracefile_write_unlock();
 857                 cfs_trace_stop_thread();
 858                 cfs_tracefile_write_lock();
 859                 memset(cfs_tracefile, 0, sizeof(cfs_tracefile));
 860
 861         } else if (strncmp(str, "size=", 5) == 0) {
 862                 cfs_tracefile_size = simple_strtoul(str + 5, NULL, 0);
 863                 if (cfs_tracefile_size < 10 || cfs_tracefile_size > 20480)
 864                         cfs_tracefile_size = CFS_TRACEFILE_SIZE;
 865                 else
 866                         cfs_tracefile_size <<= 20;
 867
 868         } else if (strlen(str) >= sizeof(cfs_tracefile)) {
 869                 rc = -ENAMETOOLONG;
 870         } else if (str[0] != '/') {
 871                 rc = -EINVAL;
 872         } else {
 873                 strcpy(cfs_tracefile, str);
 874
 875                 printk(KERN_INFO
 876                        "Lustre: debug daemon will attempt to start writing to %s (%lukB max)\n",
 877                        cfs_tracefile,
 878                        (long)(cfs_tracefile_size >> 10));
 879
 880                 cfs_trace_start_thread();
 881         }
 882
 883         cfs_tracefile_write_unlock();
 884         return rc;
 885 }
 886
 887 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
 888 {
 889         char *str;
 890         int   rc;
 891
 892         rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
 893         if (rc != 0)
 894                 return rc;
 895
 896         rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
 897                                  usr_str, usr_str_nob);
 898         if (rc == 0)
 899                 rc = cfs_trace_daemon_command(str);
 900
 901         cfs_trace_free_string_buffer(str, usr_str_nob + 1);
 902         return rc;
 903 }
 904
 905 int cfs_trace_set_debug_mb(int mb)
 906 {
 907         int i;
 908         int j;
 909         int pages;
 910         int limit = cfs_trace_max_debug_mb();
 911         struct cfs_trace_cpu_data *tcd;
 912
 913         if (mb < num_possible_cpus()) {
 914                 printk(KERN_WARNING
 915                        "Lustre: %d MB is too small for debug buffer size, setting it to %d MB.\n",
 916                        mb, num_possible_cpus());
 917                 mb = num_possible_cpus();
 918         }
 919
 920         if (mb > limit) {
 921                 printk(KERN_WARNING
 922                        "Lustre: %d MB is too large for debug buffer size, setting it to %d MB.\n",
 923                        mb, limit);
 924                 mb = limit;
 925         }
 926
 927         mb /= num_possible_cpus();
 928         pages = mb << (20 - PAGE_CACHE_SHIFT);
 929
 930         cfs_tracefile_write_lock();
 931
 932         cfs_tcd_for_each(tcd, i, j)
 933                 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
 934
 935         cfs_tracefile_write_unlock();
 936
 937         return 0;
 938 }
 939
 940 int cfs_trace_set_debug_mb_usrstr(void __user *usr_str, int usr_str_nob)
 941 {
 942         char     str[32];
 943         int      rc;
 944
 945         rc = cfs_trace_copyin_string(str, sizeof(str), usr_str, usr_str_nob);
 946         if (rc < 0)
 947                 return rc;
 948
 949         return cfs_trace_set_debug_mb(simple_strtoul(str, NULL, 0));
 950 }
 951
 952 int cfs_trace_get_debug_mb(void)
 953 {
 954         int i;
 955         int j;
 956         struct cfs_trace_cpu_data *tcd;
 957         int total_pages = 0;
 958
 959         cfs_tracefile_read_lock();
 960
 961         cfs_tcd_for_each(tcd, i, j)
 962                 total_pages += tcd->tcd_max_pages;
 963
 964         cfs_tracefile_read_unlock();
 965
 966         return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
 967 }
 968
 969 static int tracefiled(void *arg)
 970 {
 971         struct page_collection pc;
 972         struct tracefiled_ctl *tctl = arg;
 973         struct cfs_trace_page *tage;
 974         struct cfs_trace_page *tmp;
 975         struct file *filp;
 976         char *buf;
 977         int last_loop = 0;
 978         int rc;
 979
 980         DECL_MMSPACE;
 981
 982         /* we're started late enough that we pick up init's fs context */
 983         /* this is so broken in uml?  what on earth is going on? */
 984
 985         spin_lock_init(&pc.pc_lock);
 986         complete(&tctl->tctl_start);
 987
 988         while (1) {
 989                 wait_queue_t __wait;
 990
 991                 pc.pc_want_daemon_pages = 0;
 992                 collect_pages(&pc);
 993                 if (list_empty(&pc.pc_pages))
 994                         goto end_loop;
 995
 996                 filp = NULL;
 997                 cfs_tracefile_read_lock();
 998                 if (cfs_tracefile[0] != 0) {
 999                         filp = filp_open(cfs_tracefile,
1000                                          O_CREAT | O_RDWR | O_LARGEFILE,
1001                                          0600);
1002                         if (IS_ERR(filp)) {
1003                                 rc = PTR_ERR(filp);
1004                                 filp = NULL;
1005                                 printk(KERN_WARNING "couldn't open %s: %d\n",
1006                                        cfs_tracefile, rc);
1007                         }
1008                 }
1009                 cfs_tracefile_read_unlock();
1010                 if (filp == NULL) {
1011                         put_pages_on_daemon_list(&pc);
1012                         __LASSERT(list_empty(&pc.pc_pages));
1013                         goto end_loop;
1014                 }
1015
1016                 MMSPACE_OPEN;
1017
1018                 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1019                                                    linkage) {
1020                         static loff_t f_pos;
1021
1022                         __LASSERT_TAGE_INVARIANT(tage);
1023
1024                         if (f_pos >= (off_t)cfs_tracefile_size)
1025                                 f_pos = 0;
1026                         else if (f_pos > i_size_read(file_inode(filp)))
1027                                 f_pos = i_size_read(file_inode(filp));
1028
1029                         buf = kmap(tage->page);
1030                         rc = vfs_write(filp, (__force const char __user *)buf,
1031                                        tage->used, &f_pos);
1032                         kunmap(tage->page);
1033
1034                         if (rc != (int)tage->used) {
1035                                 printk(KERN_WARNING "wanted to write %u but wrote %d\n",
1036                                        tage->used, rc);
1037                                 put_pages_back(&pc);
1038                                 __LASSERT(list_empty(&pc.pc_pages));
1039                                 break;
1040                         }
1041                 }
1042                 MMSPACE_CLOSE;
1043
1044                 filp_close(filp, NULL);
1045                 put_pages_on_daemon_list(&pc);
1046                 if (!list_empty(&pc.pc_pages)) {
1047                         int i;
1048
1049                         printk(KERN_ALERT "Lustre: trace pages aren't empty\n");
1050                         pr_err("total cpus(%d): ",
1051                                 num_possible_cpus());
1052                         for (i = 0; i < num_possible_cpus(); i++)
1053                                 if (cpu_online(i))
1054                                         pr_cont("%d(on) ", i);
1055                                 else
1056                                         pr_cont("%d(off) ", i);
1057                         pr_cont("\n");
1058
1059                         i = 0;
1060                         list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1061                                                      linkage)
1062                                 pr_err("page %d belongs to cpu %d\n",
1063                                         ++i, tage->cpu);
1064                         pr_err("There are %d pages unwritten\n", i);
1065                 }
1066                 __LASSERT(list_empty(&pc.pc_pages));
1067 end_loop:
1068                 if (atomic_read(&tctl->tctl_shutdown)) {
1069                         if (last_loop == 0) {
1070                                 last_loop = 1;
1071                                 continue;
1072                         } else {
1073                                 break;
1074                         }
1075                 }
1076                 init_waitqueue_entry(&__wait, current);
1077                 add_wait_queue(&tctl->tctl_waitq, &__wait);
1078                 set_current_state(TASK_INTERRUPTIBLE);
1079                 schedule_timeout(cfs_time_seconds(1));
1080                 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1081         }
1082         complete(&tctl->tctl_stop);
1083         return 0;
1084 }
1085
1086 int cfs_trace_start_thread(void)
1087 {
1088         struct tracefiled_ctl *tctl = &trace_tctl;
1089         int rc = 0;
1090
1091         mutex_lock(&cfs_trace_thread_mutex);
1092         if (thread_running)
1093                 goto out;
1094
1095         init_completion(&tctl->tctl_start);
1096         init_completion(&tctl->tctl_stop);
1097         init_waitqueue_head(&tctl->tctl_waitq);
1098         atomic_set(&tctl->tctl_shutdown, 0);
1099
1100         if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1101                 rc = -ECHILD;
1102                 goto out;
1103         }
1104
1105         wait_for_completion(&tctl->tctl_start);
1106         thread_running = 1;
1107 out:
1108         mutex_unlock(&cfs_trace_thread_mutex);
1109         return rc;
1110 }
1111
1112 void cfs_trace_stop_thread(void)
1113 {
1114         struct tracefiled_ctl *tctl = &trace_tctl;
1115
1116         mutex_lock(&cfs_trace_thread_mutex);
1117         if (thread_running) {
1118                 printk(KERN_INFO
1119                        "Lustre: shutting down debug daemon thread...\n");
1120                 atomic_set(&tctl->tctl_shutdown, 1);
1121                 wait_for_completion(&tctl->tctl_stop);
1122                 thread_running = 0;
1123         }
1124         mutex_unlock(&cfs_trace_thread_mutex);
1125 }
1126
1127 int cfs_tracefile_init(int max_pages)
1128 {
1129         struct cfs_trace_cpu_data *tcd;
1130         int                 i;
1131         int                 j;
1132         int                 rc;
1133         int                 factor;
1134
1135         rc = cfs_tracefile_init_arch();
1136         if (rc != 0)
1137                 return rc;
1138
1139         cfs_tcd_for_each(tcd, i, j) {
1140                 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1141                 factor = tcd->tcd_pages_factor;
1142                 INIT_LIST_HEAD(&tcd->tcd_pages);
1143                 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1144                 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1145                 tcd->tcd_cur_pages = 0;
1146                 tcd->tcd_cur_stock_pages = 0;
1147                 tcd->tcd_cur_daemon_pages = 0;
1148                 tcd->tcd_max_pages = (max_pages * factor) / 100;
1149                 LASSERT(tcd->tcd_max_pages > 0);
1150                 tcd->tcd_shutting_down = 0;
1151         }
1152
1153         return 0;
1154 }
1155
1156 static void trace_cleanup_on_all_cpus(void)
1157 {
1158         struct cfs_trace_cpu_data *tcd;
1159         struct cfs_trace_page *tage;
1160         struct cfs_trace_page *tmp;
1161         int i, cpu;
1162
1163         for_each_possible_cpu(cpu) {
1164                 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1165                         tcd->tcd_shutting_down = 1;
1166
1167                         list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
1168                                                            linkage) {
1169                                 __LASSERT_TAGE_INVARIANT(tage);
1170
1171                                 list_del(&tage->linkage);
1172                                 cfs_tage_free(tage);
1173                         }
1174
1175                         tcd->tcd_cur_pages = 0;
1176                 }
1177         }
1178 }
1179
1180 static void cfs_trace_cleanup(void)
1181 {
1182         struct page_collection pc;
1183
1184         INIT_LIST_HEAD(&pc.pc_pages);
1185         spin_lock_init(&pc.pc_lock);
1186
1187         trace_cleanup_on_all_cpus();
1188
1189         cfs_tracefile_fini_arch();
1190 }
1191
1192 void cfs_tracefile_exit(void)
1193 {
1194         cfs_trace_stop_thread();
1195         cfs_trace_cleanup();
1196 }