libcfs/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, 2014, 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 <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 = 0;
  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; "
 200                         "discarding 10%% of pages (%d of %ld)\n",
 201                         pgcount + 1, tcd->tcd_cur_pages);
 202
 203         INIT_LIST_HEAD(&pc.pc_pages);
 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                 printk(KERN_ERR
 228                        "cowardly refusing to write %lu bytes in a page\n", len);
 229                 return NULL;
 230         }
 231
 232         tage = cfs_trace_get_tage_try(tcd, len);
 233         if (tage != NULL)
 234                 return tage;
 235         if (thread_running)
 236                 cfs_tcd_shrink(tcd);
 237         if (tcd->tcd_cur_pages > 0) {
 238                 tage = cfs_tage_from_list(tcd->tcd_pages.next);
 239                 tage->used = 0;
 240                 cfs_tage_to_tail(tage, &tcd->tcd_pages);
 241         }
 242         return tage;
 243 }
 244
 245 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
 246                      const char *format, ...)
 247 {
 248         va_list args;
 249         int     rc;
 250
 251         va_start(args, format);
 252         rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
 253         va_end(args);
 254
 255         return rc;
 256 }
 257 EXPORT_SYMBOL(libcfs_debug_msg);
 258
 259 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
 260                        const char *format1, va_list args,
 261                        const char *format2, ...)
 262 {
 263         struct cfs_trace_cpu_data *tcd = NULL;
 264         struct ptldebug_header     header = {0};
 265         struct cfs_trace_page     *tage;
 266         /* string_buf is used only if tcd != NULL, and is always set then */
 267         char                      *string_buf = NULL;
 268         char                      *debug_buf;
 269         int                        known_size;
 270         int                        needed = 85; /* average message length */
 271         int                        max_nob;
 272         va_list                    ap;
 273         int                        i;
 274         int                        remain;
 275         int                        mask = msgdata->msg_mask;
 276         char                      *file = (char *)msgdata->msg_file;
 277         cfs_debug_limit_state_t   *cdls = msgdata->msg_cdls;
 278
 279         if (strchr(file, '/'))
 280                 file = strrchr(file, '/') + 1;
 281
 282         tcd = cfs_trace_get_tcd();
 283
 284         /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
 285          * pins us to a particular CPU.  This avoids an smp_processor_id()
 286          * warning on Linux when debugging is enabled. */
 287         cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
 288
 289         if (tcd == NULL)                /* arch may not log in IRQ context */
 290                 goto console;
 291
 292         if (tcd->tcd_cur_pages == 0)
 293                 header.ph_flags |= PH_FLAG_FIRST_RECORD;
 294
 295         if (tcd->tcd_shutting_down) {
 296                 cfs_trace_put_tcd(tcd);
 297                 tcd = NULL;
 298                 goto console;
 299         }
 300
 301         known_size = strlen(file) + 1;
 302         if (msgdata->msg_fn)
 303                 known_size += strlen(msgdata->msg_fn) + 1;
 304
 305         if (libcfs_debug_binary)
 306                 known_size += sizeof(header);
 307
 308         /*/
 309          * '2' used because vsnprintf return real size required for output
 310          * _without_ terminating NULL.
 311          * if needed is to small for this format.
 312          */
 313         for (i = 0; i < 2; i++) {
 314                 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
 315                 if (tage == NULL) {
 316                         if (needed + known_size > PAGE_CACHE_SIZE)
 317                                 mask |= D_ERROR;
 318
 319                         cfs_trace_put_tcd(tcd);
 320                         tcd = NULL;
 321                         goto console;
 322                 }
 323
 324                 string_buf = (char *)page_address(tage->page) +
 325                                         tage->used + known_size;
 326
 327                 max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
 328                 if (max_nob <= 0) {
 329                         printk(KERN_EMERG "negative max_nob: %d\n",
 330                                max_nob);
 331                         mask |= D_ERROR;
 332                         cfs_trace_put_tcd(tcd);
 333                         tcd = NULL;
 334                         goto console;
 335                 }
 336
 337                 needed = 0;
 338                 if (format1) {
 339                         va_copy(ap, args);
 340                         needed = vsnprintf(string_buf, max_nob, format1, ap);
 341                         va_end(ap);
 342                 }
 343
 344                 if (format2) {
 345                         remain = max_nob - needed;
 346                         if (remain < 0)
 347                                 remain = 0;
 348
 349                         va_start(ap, format2);
 350                         needed += vsnprintf(string_buf + needed, remain,
 351                                             format2, ap);
 352                         va_end(ap);
 353                 }
 354
 355                 if (needed < max_nob) /* well. printing ok.. */
 356                         break;
 357         }
 358
 359         if (*(string_buf+needed-1) != '\n')
 360                 printk(KERN_INFO "format at %s:%d:%s doesn't end in "
 361                        "newline\n", file, msgdata->msg_line, msgdata->msg_fn);
 362
 363         header.ph_len = known_size + needed;
 364         debug_buf = (char *)page_address(tage->page) + tage->used;
 365
 366         if (libcfs_debug_binary) {
 367                 memcpy(debug_buf, &header, sizeof(header));
 368                 tage->used += sizeof(header);
 369                 debug_buf += sizeof(header);
 370         }
 371
 372         strcpy(debug_buf, file);
 373         tage->used += strlen(file) + 1;
 374         debug_buf += strlen(file) + 1;
 375
 376         if (msgdata->msg_fn) {
 377                 strcpy(debug_buf, msgdata->msg_fn);
 378                 tage->used += strlen(msgdata->msg_fn) + 1;
 379                 debug_buf += strlen(msgdata->msg_fn) + 1;
 380         }
 381
 382         __LASSERT(debug_buf == string_buf);
 383
 384         tage->used += needed;
 385         __LASSERT(tage->used <= PAGE_CACHE_SIZE);
 386
 387 console:
 388         if ((mask & libcfs_printk) == 0) {
 389                 /* no console output requested */
 390                 if (tcd != NULL)
 391                         cfs_trace_put_tcd(tcd);
 392                 return 1;
 393         }
 394
 395         if (cdls != NULL) {
 396                 if (libcfs_console_ratelimit &&
 397                     cdls->cdls_next != 0 &&     /* not first time ever */
 398                     !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
 399                         /* skipping a console message */
 400                         cdls->cdls_count++;
 401                         if (tcd != NULL)
 402                                 cfs_trace_put_tcd(tcd);
 403                         return 1;
 404                 }
 405
 406                 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
 407                                                        libcfs_console_max_delay
 408                                                        + cfs_time_seconds(10))) {
 409                         /* last timeout was a long time ago */
 410                         cdls->cdls_delay /= libcfs_console_backoff * 4;
 411                 } else {
 412                         cdls->cdls_delay *= libcfs_console_backoff;
 413                 }
 414
 415                 if (cdls->cdls_delay < libcfs_console_min_delay)
 416                         cdls->cdls_delay = libcfs_console_min_delay;
 417                 else if (cdls->cdls_delay > libcfs_console_max_delay)
 418                         cdls->cdls_delay = libcfs_console_max_delay;
 419
 420                 /* ensure cdls_next is never zero after it's been seen */
 421                 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
 422         }
 423
 424         if (tcd != NULL) {
 425                 cfs_print_to_console(&header, mask, string_buf, needed, file,
 426                                      msgdata->msg_fn);
 427                 cfs_trace_put_tcd(tcd);
 428         } else {
 429                 string_buf = cfs_trace_get_console_buffer();
 430
 431                 needed = 0;
 432                 if (format1 != NULL) {
 433                         va_copy(ap, args);
 434                         needed = vsnprintf(string_buf,
 435                                            CFS_TRACE_CONSOLE_BUFFER_SIZE,
 436                                            format1, ap);
 437                         va_end(ap);
 438                 }
 439                 if (format2 != NULL) {
 440                         remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
 441                         if (remain > 0) {
 442                                 va_start(ap, format2);
 443                                 needed += vsnprintf(string_buf+needed, remain,
 444                                                     format2, ap);
 445                                 va_end(ap);
 446                         }
 447                 }
 448                 cfs_print_to_console(&header, mask,
 449                                      string_buf, needed, file, msgdata->msg_fn);
 450
 451                 cfs_trace_put_console_buffer(string_buf);
 452         }
 453
 454         if (cdls != NULL && cdls->cdls_count != 0) {
 455                 string_buf = cfs_trace_get_console_buffer();
 456
 457                 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
 458                                   "Skipped %d previous similar message%s\n",
 459                                   cdls->cdls_count,
 460                                   (cdls->cdls_count > 1) ? "s" : "");
 461
 462                 cfs_print_to_console(&header, mask,
 463                                      string_buf, needed, file, msgdata->msg_fn);
 464
 465                 cfs_trace_put_console_buffer(string_buf);
 466                 cdls->cdls_count = 0;
 467         }
 468
 469         return 0;
 470 }
 471 EXPORT_SYMBOL(libcfs_debug_vmsg2);
 472
 473 void
 474 cfs_trace_assertion_failed(const char *str,
 475                            struct libcfs_debug_msg_data *msgdata)
 476 {
 477         struct ptldebug_header hdr;
 478
 479         libcfs_panic_in_progress = 1;
 480         libcfs_catastrophe = 1;
 481         smp_mb();
 482
 483         cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
 484
 485         cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
 486                              msgdata->msg_file, msgdata->msg_fn);
 487
 488         panic("Lustre debug assertion failure\n");
 489
 490         /* not reached */
 491 }
 492
 493 static void
 494 panic_collect_pages(struct page_collection *pc)
 495 {
 496         /* Do the collect_pages job on a single CPU: assumes that all other
 497          * CPUs have been stopped during a panic.  If this isn't true for some
 498          * arch, this will have to be implemented separately in each arch.  */
 499         int                        i;
 500         int                        j;
 501         struct cfs_trace_cpu_data *tcd;
 502
 503         INIT_LIST_HEAD(&pc->pc_pages);
 504
 505         cfs_tcd_for_each(tcd, i, j) {
 506                 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 507                 tcd->tcd_cur_pages = 0;
 508
 509                 if (pc->pc_want_daemon_pages) {
 510                         list_splice_init(&tcd->tcd_daemon_pages,
 511                                                 &pc->pc_pages);
 512                         tcd->tcd_cur_daemon_pages = 0;
 513                 }
 514         }
 515 }
 516
 517 static void collect_pages_on_all_cpus(struct page_collection *pc)
 518 {
 519         struct cfs_trace_cpu_data *tcd;
 520         int i, cpu;
 521
 522         for_each_possible_cpu(cpu) {
 523                 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
 524                         list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
 525                         tcd->tcd_cur_pages = 0;
 526                         if (pc->pc_want_daemon_pages) {
 527                                 list_splice_init(&tcd->tcd_daemon_pages,
 528                                                         &pc->pc_pages);
 529                                 tcd->tcd_cur_daemon_pages = 0;
 530                         }
 531                 }
 532         }
 533 }
 534
 535 static void collect_pages(struct page_collection *pc)
 536 {
 537         INIT_LIST_HEAD(&pc->pc_pages);
 538
 539         if (libcfs_panic_in_progress)
 540                 panic_collect_pages(pc);
 541         else
 542                 collect_pages_on_all_cpus(pc);
 543 }
 544
 545 static void put_pages_back_on_all_cpus(struct page_collection *pc)
 546 {
 547         struct cfs_trace_cpu_data *tcd;
 548         struct list_head *cur_head;
 549         struct cfs_trace_page *tage;
 550         struct cfs_trace_page *tmp;
 551         int i, cpu;
 552
 553         for_each_possible_cpu(cpu) {
 554                 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
 555                         cur_head = tcd->tcd_pages.next;
 556
 557                         list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
 558                                                  linkage) {
 559
 560                                 __LASSERT_TAGE_INVARIANT(tage);
 561
 562                                 if (tage->cpu != cpu || tage->type != i)
 563                                         continue;
 564
 565                                 cfs_tage_to_tail(tage, cur_head);
 566                                 tcd->tcd_cur_pages++;
 567                         }
 568                 }
 569         }
 570 }
 571
 572 static void put_pages_back(struct page_collection *pc)
 573 {
 574         if (!libcfs_panic_in_progress)
 575                 put_pages_back_on_all_cpus(pc);
 576 }
 577
 578 /* Add pages to a per-cpu debug daemon ringbuffer.  This buffer makes sure that
 579  * we have a good amount of data at all times for dumping during an LBUG, even
 580  * if we have been steadily writing (and otherwise discarding) pages via the
 581  * debug daemon. */
 582 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
 583                                          struct cfs_trace_cpu_data *tcd)
 584 {
 585         struct cfs_trace_page *tage;
 586         struct cfs_trace_page *tmp;
 587
 588         list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
 589                 __LASSERT_TAGE_INVARIANT(tage);
 590
 591                 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
 592                         continue;
 593
 594                 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
 595                 tcd->tcd_cur_daemon_pages++;
 596
 597                 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
 598                         struct cfs_trace_page *victim;
 599
 600                         __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
 601                         victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
 602
 603                         __LASSERT_TAGE_INVARIANT(victim);
 604
 605                         list_del(&victim->linkage);
 606                         cfs_tage_free(victim);
 607                         tcd->tcd_cur_daemon_pages--;
 608                 }
 609         }
 610 }
 611
 612 static void put_pages_on_daemon_list(struct page_collection *pc)
 613 {
 614         struct cfs_trace_cpu_data *tcd;
 615         int i, cpu;
 616
 617         for_each_possible_cpu(cpu) {
 618                 cfs_tcd_for_each_type_lock(tcd, i, cpu)
 619                         put_pages_on_tcd_daemon_list(pc, tcd);
 620         }
 621 }
 622
 623 void cfs_trace_debug_print(void)
 624 {
 625         struct page_collection pc;
 626         struct cfs_trace_page *tage;
 627         struct cfs_trace_page *tmp;
 628
 629         pc.pc_want_daemon_pages = 1;
 630         collect_pages(&pc);
 631         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 632                 char *p, *file, *fn;
 633                 struct page *page;
 634
 635                 __LASSERT_TAGE_INVARIANT(tage);
 636
 637                 page = tage->page;
 638                 p = page_address(page);
 639                 while (p < ((char *)page_address(page) + tage->used)) {
 640                         struct ptldebug_header *hdr;
 641                         int len;
 642                         hdr = (void *)p;
 643                         p += sizeof(*hdr);
 644                         file = p;
 645                         p += strlen(file) + 1;
 646                         fn = p;
 647                         p += strlen(fn) + 1;
 648                         len = hdr->ph_len - (int)(p - (char *)hdr);
 649
 650                         cfs_print_to_console(hdr, D_EMERG, p, len, file, fn);
 651
 652                         p += len;
 653                 }
 654
 655                 list_del(&tage->linkage);
 656                 cfs_tage_free(tage);
 657         }
 658 }
 659
 660 int cfs_tracefile_dump_all_pages(char *filename)
 661 {
 662         struct page_collection  pc;
 663         struct file             *filp;
 664         struct cfs_trace_page   *tage;
 665         struct cfs_trace_page   *tmp;
 666         int rc;
 667
 668         DECL_MMSPACE;
 669
 670         cfs_tracefile_write_lock();
 671
 672         filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
 673         if (IS_ERR(filp)) {
 674                 rc = PTR_ERR(filp);
 675                 filp = NULL;
 676                 printk(KERN_ERR "LustreError: can't open %s for dump: rc %d\n",
 677                       filename, rc);
 678                 goto out;
 679         }
 680
 681         pc.pc_want_daemon_pages = 1;
 682         collect_pages(&pc);
 683         if (list_empty(&pc.pc_pages)) {
 684                 rc = 0;
 685                 goto close;
 686         }
 687
 688         /* ok, for now, just write the pages.  in the future we'll be building
 689          * iobufs with the pages and calling generic_direct_IO */
 690         MMSPACE_OPEN;
 691         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 692
 693                 __LASSERT_TAGE_INVARIANT(tage);
 694
 695                 rc = filp_write(filp, page_address(tage->page),
 696                                 tage->used, 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                 cfs_tage_free(tage);
 706         }
 707         MMSPACE_CLOSE;
 708         rc = ll_vfs_fsync_range(filp, 0, LLONG_MAX, 1);
 709         if (rc)
 710                 printk(KERN_ERR "sync returns %d\n", rc);
 711 close:
 712         filp_close(filp, NULL);
 713 out:
 714         cfs_tracefile_write_unlock();
 715         return rc;
 716 }
 717
 718 void cfs_trace_flush_pages(void)
 719 {
 720         struct page_collection pc;
 721         struct cfs_trace_page *tage;
 722         struct cfs_trace_page *tmp;
 723
 724         pc.pc_want_daemon_pages = 1;
 725         collect_pages(&pc);
 726         list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 727
 728                 __LASSERT_TAGE_INVARIANT(tage);
 729
 730                 list_del(&tage->linkage);
 731                 cfs_tage_free(tage);
 732         }
 733 }
 734
 735 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
 736                             const char __user *usr_buffer, int usr_buffer_nob)
 737 {
 738         int    nob;
 739
 740         if (usr_buffer_nob > knl_buffer_nob)
 741                 return -EOVERFLOW;
 742
 743         if (copy_from_user(knl_buffer, usr_buffer, usr_buffer_nob))
 744                 return -EFAULT;
 745
 746         nob = strnlen(knl_buffer, usr_buffer_nob);
 747         while (nob-- >= 0)                      /* strip trailing whitespace */
 748                 if (!isspace(knl_buffer[nob]))
 749                         break;
 750
 751         if (nob < 0)                            /* empty string */
 752                 return -EINVAL;
 753
 754         if (nob == knl_buffer_nob)              /* no space to terminate */
 755                 return -EOVERFLOW;
 756
 757         knl_buffer[nob + 1] = 0;                /* terminate */
 758         return 0;
 759 }
 760 EXPORT_SYMBOL(cfs_trace_copyin_string);
 761
 762 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
 763                              const char *knl_buffer, char *append)
 764 {
 765         /* NB if 'append' != NULL, it's a single character to append to the
 766          * copied out string - usually "\n", for /proc entries and "" (i.e. a
 767          * terminating zero byte) for sysctl entries */
 768         int   nob = strlen(knl_buffer);
 769
 770         if (nob > usr_buffer_nob)
 771                 nob = usr_buffer_nob;
 772
 773         if (copy_to_user(usr_buffer, knl_buffer, nob))
 774                 return -EFAULT;
 775
 776         if (append != NULL && nob < usr_buffer_nob) {
 777                 if (copy_to_user(usr_buffer + nob, append, 1))
 778                         return -EFAULT;
 779
 780                 nob++;
 781         }
 782
 783         return nob;
 784 }
 785 EXPORT_SYMBOL(cfs_trace_copyout_string);
 786
 787 int cfs_trace_allocate_string_buffer(char **str, int nob)
 788 {
 789         if (nob > 2 * PAGE_CACHE_SIZE)  /* string must be "sensible" */
 790                 return -EINVAL;
 791
 792         *str = kmalloc(nob, GFP_IOFS | __GFP_ZERO);
 793         if (*str == NULL)
 794                 return -ENOMEM;
 795
 796         return 0;
 797 }
 798
 799 void cfs_trace_free_string_buffer(char *str, int nob)
 800 {
 801         kfree(str);
 802 }
 803
 804 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
 805 {
 806         char         *str;
 807         int           rc;
 808
 809         rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
 810         if (rc != 0)
 811                 return rc;
 812
 813         rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
 814                                      usr_str, usr_str_nob);
 815         if (rc != 0)
 816                 goto out;
 817
 818         if (str[0] != '/') {
 819                 rc = -EINVAL;
 820                 goto out;
 821         }
 822         rc = cfs_tracefile_dump_all_pages(str);
 823 out:
 824         cfs_trace_free_string_buffer(str, usr_str_nob + 1);
 825         return rc;
 826 }
 827
 828 int cfs_trace_daemon_command(char *str)
 829 {
 830         int       rc = 0;
 831
 832         cfs_tracefile_write_lock();
 833
 834         if (strcmp(str, "stop") == 0) {
 835                 cfs_tracefile_write_unlock();
 836                 cfs_trace_stop_thread();
 837                 cfs_tracefile_write_lock();
 838                 memset(cfs_tracefile, 0, sizeof(cfs_tracefile));
 839
 840         } else if (strncmp(str, "size=", 5) == 0) {
 841                 cfs_tracefile_size = simple_strtoul(str + 5, NULL, 0);
 842                 if (cfs_tracefile_size < 10 || cfs_tracefile_size > 20480)
 843                         cfs_tracefile_size = CFS_TRACEFILE_SIZE;
 844                 else
 845                         cfs_tracefile_size <<= 20;
 846
 847         } else if (strlen(str) >= sizeof(cfs_tracefile)) {
 848                 rc = -ENAMETOOLONG;
 849         } else if (str[0] != '/') {
 850                 rc = -EINVAL;
 851         } else {
 852                 strcpy(cfs_tracefile, str);
 853
 854                 printk(KERN_INFO
 855                        "Lustre: debug daemon will attempt to start writing "
 856                        "to %s (%lukB max)\n", cfs_tracefile,
 857                        (long)(cfs_tracefile_size >> 10));
 858
 859                 cfs_trace_start_thread();
 860         }
 861
 862         cfs_tracefile_write_unlock();
 863         return rc;
 864 }
 865
 866 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
 867 {
 868         char *str;
 869         int   rc;
 870
 871         rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
 872         if (rc != 0)
 873                 return rc;
 874
 875         rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
 876                                  usr_str, usr_str_nob);
 877         if (rc == 0)
 878                 rc = cfs_trace_daemon_command(str);
 879
 880         cfs_trace_free_string_buffer(str, usr_str_nob + 1);
 881         return rc;
 882 }
 883
 884 int cfs_trace_set_debug_mb(int mb)
 885 {
 886         int i;
 887         int j;
 888         int pages;
 889         int limit = cfs_trace_max_debug_mb();
 890         struct cfs_trace_cpu_data *tcd;
 891
 892         if (mb < num_possible_cpus()) {
 893                 printk(KERN_WARNING
 894                        "Lustre: %d MB is too small for debug buffer size, "
 895                        "setting it to %d MB.\n", mb, num_possible_cpus());
 896                 mb = num_possible_cpus();
 897         }
 898
 899         if (mb > limit) {
 900                 printk(KERN_WARNING
 901                        "Lustre: %d MB is too large for debug buffer size, "
 902                        "setting it to %d MB.\n", mb, limit);
 903                 mb = limit;
 904         }
 905
 906         mb /= num_possible_cpus();
 907         pages = mb << (20 - PAGE_CACHE_SHIFT);
 908
 909         cfs_tracefile_write_lock();
 910
 911         cfs_tcd_for_each(tcd, i, j)
 912                 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
 913
 914         cfs_tracefile_write_unlock();
 915
 916         return 0;
 917 }
 918
 919 int cfs_trace_set_debug_mb_usrstr(void __user *usr_str, int usr_str_nob)
 920 {
 921         char     str[32];
 922         int      rc;
 923
 924         rc = cfs_trace_copyin_string(str, sizeof(str), usr_str, usr_str_nob);
 925         if (rc < 0)
 926                 return rc;
 927
 928         return cfs_trace_set_debug_mb(simple_strtoul(str, NULL, 0));
 929 }
 930
 931 int cfs_trace_get_debug_mb(void)
 932 {
 933         int i;
 934         int j;
 935         struct cfs_trace_cpu_data *tcd;
 936         int total_pages = 0;
 937
 938         cfs_tracefile_read_lock();
 939
 940         cfs_tcd_for_each(tcd, i, j)
 941                 total_pages += tcd->tcd_max_pages;
 942
 943         cfs_tracefile_read_unlock();
 944
 945         return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
 946 }
 947
 948 static int tracefiled(void *arg)
 949 {
 950         struct page_collection pc;
 951         struct tracefiled_ctl *tctl = arg;
 952         struct cfs_trace_page *tage;
 953         struct cfs_trace_page *tmp;
 954         struct file *filp;
 955         int last_loop = 0;
 956         int rc;
 957
 958         DECL_MMSPACE;
 959
 960         /* we're started late enough that we pick up init's fs context */
 961         /* this is so broken in uml?  what on earth is going on? */
 962
 963         complete(&tctl->tctl_start);
 964
 965         while (1) {
 966                 wait_queue_t __wait;
 967
 968                 pc.pc_want_daemon_pages = 0;
 969                 collect_pages(&pc);
 970                 if (list_empty(&pc.pc_pages))
 971                         goto end_loop;
 972
 973                 filp = NULL;
 974                 cfs_tracefile_read_lock();
 975                 if (cfs_tracefile[0] != 0) {
 976                         filp = filp_open(cfs_tracefile,
 977                                          O_CREAT | O_RDWR | O_LARGEFILE,
 978                                          0600);
 979                         if (IS_ERR(filp)) {
 980                                 rc = PTR_ERR(filp);
 981                                 filp = NULL;
 982                                 printk(KERN_WARNING "couldn't open %s: "
 983                                        "%d\n", cfs_tracefile, rc);
 984                         }
 985                 }
 986                 cfs_tracefile_read_unlock();
 987                 if (filp == NULL) {
 988                         put_pages_on_daemon_list(&pc);
 989                         __LASSERT(list_empty(&pc.pc_pages));
 990                         goto end_loop;
 991                 }
 992
 993                 MMSPACE_OPEN;
 994
 995                 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 996                         static loff_t f_pos;
 997
 998                         __LASSERT_TAGE_INVARIANT(tage);
 999
1000                         if (f_pos >= (off_t)cfs_tracefile_size)
1001                                 f_pos = 0;
1002                         else if (f_pos > (off_t)filp_size(filp))
1003                                 f_pos = filp_size(filp);
1004
1005                         rc = filp_write(filp, page_address(tage->page),
1006                                         tage->used, &f_pos);
1007                         if (rc != (int)tage->used) {
1008                                 printk(KERN_WARNING "wanted to write %u "
1009                                        "but wrote %d\n", tage->used, rc);
1010                                 put_pages_back(&pc);
1011                                 __LASSERT(list_empty(&pc.pc_pages));
1012                                 break;
1013                         }
1014                 }
1015                 MMSPACE_CLOSE;
1016
1017                 filp_close(filp, NULL);
1018                 put_pages_on_daemon_list(&pc);
1019                 if (!list_empty(&pc.pc_pages)) {
1020                         int i;
1021
1022                         printk(KERN_ALERT "Lustre: trace pages aren't "
1023                                " empty\n");
1024                         printk(KERN_ERR "total cpus(%d): ",
1025                                num_possible_cpus());
1026                         for (i = 0; i < num_possible_cpus(); i++)
1027                                 if (cpu_online(i))
1028                                         printk(KERN_ERR "%d(on) ", i);
1029                                 else
1030                                         printk(KERN_ERR "%d(off) ", i);
1031                         printk(KERN_ERR "\n");
1032
1033                         i = 0;
1034                         list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1035                                                      linkage)
1036                                 printk(KERN_ERR "page %d belongs to cpu "
1037                                        "%d\n", ++i, tage->cpu);
1038                         printk(KERN_ERR "There are %d pages unwritten\n",
1039                                i);
1040                 }
1041                 __LASSERT(list_empty(&pc.pc_pages));
1042 end_loop:
1043                 if (atomic_read(&tctl->tctl_shutdown)) {
1044                         if (last_loop == 0) {
1045                                 last_loop = 1;
1046                                 continue;
1047                         } else {
1048                                 break;
1049                         }
1050                 }
1051                 init_waitqueue_entry_current(&__wait);
1052                 add_wait_queue(&tctl->tctl_waitq, &__wait);
1053                 set_current_state(TASK_INTERRUPTIBLE);
1054                 waitq_timedwait(&__wait, TASK_INTERRUPTIBLE,
1055                                 cfs_time_seconds(1));
1056                 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1057         }
1058         complete(&tctl->tctl_stop);
1059         return 0;
1060 }
1061
1062 int cfs_trace_start_thread(void)
1063 {
1064         struct tracefiled_ctl *tctl = &trace_tctl;
1065         int rc = 0;
1066
1067         mutex_lock(&cfs_trace_thread_mutex);
1068         if (thread_running)
1069                 goto out;
1070
1071         init_completion(&tctl->tctl_start);
1072         init_completion(&tctl->tctl_stop);
1073         init_waitqueue_head(&tctl->tctl_waitq);
1074         atomic_set(&tctl->tctl_shutdown, 0);
1075
1076         if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1077                 rc = -ECHILD;
1078                 goto out;
1079         }
1080
1081         wait_for_completion(&tctl->tctl_start);
1082         thread_running = 1;
1083 out:
1084         mutex_unlock(&cfs_trace_thread_mutex);
1085         return rc;
1086 }
1087
1088 void cfs_trace_stop_thread(void)
1089 {
1090         struct tracefiled_ctl *tctl = &trace_tctl;
1091
1092         mutex_lock(&cfs_trace_thread_mutex);
1093         if (thread_running) {
1094                 printk(KERN_INFO
1095                        "Lustre: shutting down debug daemon thread...\n");
1096                 atomic_set(&tctl->tctl_shutdown, 1);
1097                 wait_for_completion(&tctl->tctl_stop);
1098                 thread_running = 0;
1099         }
1100         mutex_unlock(&cfs_trace_thread_mutex);
1101 }
1102
1103 int cfs_tracefile_init(int max_pages)
1104 {
1105         struct cfs_trace_cpu_data *tcd;
1106         int     i;
1107         int     j;
1108         int     rc;
1109         int     factor;
1110
1111         rc = cfs_tracefile_init_arch();
1112         if (rc != 0)
1113                 return rc;
1114
1115         cfs_tcd_for_each(tcd, i, j) {
1116                 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1117                 factor = tcd->tcd_pages_factor;
1118                 INIT_LIST_HEAD(&tcd->tcd_pages);
1119                 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1120                 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1121                 tcd->tcd_cur_pages = 0;
1122                 tcd->tcd_cur_stock_pages = 0;
1123                 tcd->tcd_cur_daemon_pages = 0;
1124                 tcd->tcd_max_pages = (max_pages * factor) / 100;
1125                 LASSERT(tcd->tcd_max_pages > 0);
1126                 tcd->tcd_shutting_down = 0;
1127         }
1128         return 0;
1129 }
1130
1131 static void trace_cleanup_on_all_cpus(void)
1132 {
1133         struct cfs_trace_cpu_data *tcd;
1134         struct cfs_trace_page *tage;
1135         struct cfs_trace_page *tmp;
1136         int i, cpu;
1137
1138         for_each_possible_cpu(cpu) {
1139                 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1140                         tcd->tcd_shutting_down = 1;
1141
1142                         list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
1143                                 __LASSERT_TAGE_INVARIANT(tage);
1144
1145                                 list_del(&tage->linkage);
1146                                 cfs_tage_free(tage);
1147                         }
1148                         tcd->tcd_cur_pages = 0;
1149                 }
1150         }
1151 }
1152
1153 static void cfs_trace_cleanup(void)
1154 {
1155         struct page_collection pc;
1156
1157         INIT_LIST_HEAD(&pc.pc_pages);
1158
1159         trace_cleanup_on_all_cpus();
1160
1161         cfs_tracefile_fini_arch();
1162 }
1163
1164 void cfs_tracefile_exit(void)
1165 {
1166         cfs_trace_stop_thread();
1167         cfs_trace_cleanup();
1168 }