fs/dlm/debug_fs.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) 2005-2009 Red Hat, Inc.  All rights reserved.
   5 **
   6 **  This copyrighted material is made available to anyone wishing to use,
   7 **  modify, copy, or redistribute it subject to the terms and conditions
   8 **  of the GNU General Public License v.2.
   9 **
  10 *******************************************************************************
  11 ******************************************************************************/
  12
  13 #include <linux/pagemap.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/module.h>
  16 #include <linux/ctype.h>
  17 #include <linux/debugfs.h>
  18 #include <linux/slab.h>
  19
  20 #include "dlm_internal.h"
  21 #include "lock.h"
  22
  23 #define DLM_DEBUG_BUF_LEN 4096
  24 static char debug_buf[DLM_DEBUG_BUF_LEN];
  25 static struct mutex debug_buf_lock;
  26
  27 static struct dentry *dlm_root;
  28
  29 static char *print_lockmode(int mode)
  30 {
  31         switch (mode) {
  32         case DLM_LOCK_IV:
  33                 return "--";
  34         case DLM_LOCK_NL:
  35                 return "NL";
  36         case DLM_LOCK_CR:
  37                 return "CR";
  38         case DLM_LOCK_CW:
  39                 return "CW";
  40         case DLM_LOCK_PR:
  41                 return "PR";
  42         case DLM_LOCK_PW:
  43                 return "PW";
  44         case DLM_LOCK_EX:
  45                 return "EX";
  46         default:
  47                 return "??";
  48         }
  49 }
  50
  51 static int print_format1_lock(struct seq_file *s, struct dlm_lkb *lkb,
  52                               struct dlm_rsb *res)
  53 {
  54         seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
  55
  56         if (lkb->lkb_status == DLM_LKSTS_CONVERT ||
  57             lkb->lkb_status == DLM_LKSTS_WAITING)
  58                 seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
  59
  60         if (lkb->lkb_nodeid) {
  61                 if (lkb->lkb_nodeid != res->res_nodeid)
  62                         seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
  63                                    lkb->lkb_remid);
  64                 else
  65                         seq_printf(s, " Master:     %08x", lkb->lkb_remid);
  66         }
  67
  68         if (lkb->lkb_wait_type)
  69                 seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
  70
  71         return seq_printf(s, "\n");
  72 }
  73
  74 static int print_format1(struct dlm_rsb *res, struct seq_file *s)
  75 {
  76         struct dlm_lkb *lkb;
  77         int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
  78         int rv;
  79
  80         lock_rsb(res);
  81
  82         rv = seq_printf(s, "\nResource %p Name (len=%d) \"",
  83                         res, res->res_length);
  84         if (rv)
  85                 goto out;
  86
  87         for (i = 0; i < res->res_length; i++) {
  88                 if (isprint(res->res_name[i]))
  89                         seq_printf(s, "%c", res->res_name[i]);
  90                 else
  91                         seq_printf(s, "%c", '.');
  92         }
  93
  94         if (res->res_nodeid > 0)
  95                 rv = seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
  96                                 res->res_nodeid);
  97         else if (res->res_nodeid == 0)
  98                 rv = seq_printf(s, "\"  \nMaster Copy\n");
  99         else if (res->res_nodeid == -1)
 100                 rv = seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
 101                                 res->res_first_lkid);
 102         else
 103                 rv = seq_printf(s, "\"  \nInvalid master %d\n",
 104                                 res->res_nodeid);
 105         if (rv)
 106                 goto out;
 107
 108         /* Print the LVB: */
 109         if (res->res_lvbptr) {
 110                 seq_printf(s, "LVB: ");
 111                 for (i = 0; i < lvblen; i++) {
 112                         if (i == lvblen / 2)
 113                                 seq_printf(s, "\n     ");
 114                         seq_printf(s, "%02x ",
 115                                    (unsigned char) res->res_lvbptr[i]);
 116                 }
 117                 if (rsb_flag(res, RSB_VALNOTVALID))
 118                         seq_printf(s, " (INVALID)");
 119                 rv = seq_printf(s, "\n");
 120                 if (rv)
 121                         goto out;
 122         }
 123
 124         root_list = !list_empty(&res->res_root_list);
 125         recover_list = !list_empty(&res->res_recover_list);
 126
 127         if (root_list || recover_list) {
 128                 rv = seq_printf(s, "Recovery: root %d recover %d flags %lx "
 129                                 "count %d\n", root_list, recover_list,
 130                                 res->res_flags, res->res_recover_locks_count);
 131                 if (rv)
 132                         goto out;
 133         }
 134
 135         /* Print the locks attached to this resource */
 136         seq_printf(s, "Granted Queue\n");
 137         list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue) {
 138                 rv = print_format1_lock(s, lkb, res);
 139                 if (rv)
 140                         goto out;
 141         }
 142
 143         seq_printf(s, "Conversion Queue\n");
 144         list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue) {
 145                 rv = print_format1_lock(s, lkb, res);
 146                 if (rv)
 147                         goto out;
 148         }
 149
 150         seq_printf(s, "Waiting Queue\n");
 151         list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue) {
 152                 rv = print_format1_lock(s, lkb, res);
 153                 if (rv)
 154                         goto out;
 155         }
 156
 157         if (list_empty(&res->res_lookup))
 158                 goto out;
 159
 160         seq_printf(s, "Lookup Queue\n");
 161         list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
 162                 rv = seq_printf(s, "%08x %s", lkb->lkb_id,
 163                                 print_lockmode(lkb->lkb_rqmode));
 164                 if (lkb->lkb_wait_type)
 165                         seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
 166                 rv = seq_printf(s, "\n");
 167         }
 168  out:
 169         unlock_rsb(res);
 170         return rv;
 171 }
 172
 173 static int print_format2_lock(struct seq_file *s, struct dlm_lkb *lkb,
 174                               struct dlm_rsb *r)
 175 {
 176         u64 xid = 0;
 177         u64 us;
 178         int rv;
 179
 180         if (lkb->lkb_flags & DLM_IFL_USER) {
 181                 if (lkb->lkb_ua)
 182                         xid = lkb->lkb_ua->xid;
 183         }
 184
 185         /* microseconds since lkb was added to current queue */
 186         us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_timestamp));
 187
 188         /* id nodeid remid pid xid exflags flags sts grmode rqmode time_us
 189            r_nodeid r_len r_name */
 190
 191         rv = seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %llu %u %d \"%s\"\n",
 192                         lkb->lkb_id,
 193                         lkb->lkb_nodeid,
 194                         lkb->lkb_remid,
 195                         lkb->lkb_ownpid,
 196                         (unsigned long long)xid,
 197                         lkb->lkb_exflags,
 198                         lkb->lkb_flags,
 199                         lkb->lkb_status,
 200                         lkb->lkb_grmode,
 201                         lkb->lkb_rqmode,
 202                         (unsigned long long)us,
 203                         r->res_nodeid,
 204                         r->res_length,
 205                         r->res_name);
 206         return rv;
 207 }
 208
 209 static int print_format2(struct dlm_rsb *r, struct seq_file *s)
 210 {
 211         struct dlm_lkb *lkb;
 212         int rv = 0;
 213
 214         lock_rsb(r);
 215
 216         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
 217                 rv = print_format2_lock(s, lkb, r);
 218                 if (rv)
 219                         goto out;
 220         }
 221
 222         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
 223                 rv = print_format2_lock(s, lkb, r);
 224                 if (rv)
 225                         goto out;
 226         }
 227
 228         list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
 229                 rv = print_format2_lock(s, lkb, r);
 230                 if (rv)
 231                         goto out;
 232         }
 233  out:
 234         unlock_rsb(r);
 235         return rv;
 236 }
 237
 238 static int print_format3_lock(struct seq_file *s, struct dlm_lkb *lkb,
 239                               int rsb_lookup)
 240 {
 241         u64 xid = 0;
 242         int rv;
 243
 244         if (lkb->lkb_flags & DLM_IFL_USER) {
 245                 if (lkb->lkb_ua)
 246                         xid = lkb->lkb_ua->xid;
 247         }
 248
 249         rv = seq_printf(s, "lkb %x %d %x %u %llu %x %x %d %d %d %d %d %d %u %llu %llu\n",
 250                         lkb->lkb_id,
 251                         lkb->lkb_nodeid,
 252                         lkb->lkb_remid,
 253                         lkb->lkb_ownpid,
 254                         (unsigned long long)xid,
 255                         lkb->lkb_exflags,
 256                         lkb->lkb_flags,
 257                         lkb->lkb_status,
 258                         lkb->lkb_grmode,
 259                         lkb->lkb_rqmode,
 260                         lkb->lkb_last_bast.mode,
 261                         rsb_lookup,
 262                         lkb->lkb_wait_type,
 263                         lkb->lkb_lvbseq,
 264                         (unsigned long long)ktime_to_ns(lkb->lkb_timestamp),
 265                         (unsigned long long)ktime_to_ns(lkb->lkb_last_bast_time));
 266         return rv;
 267 }
 268
 269 static int print_format3(struct dlm_rsb *r, struct seq_file *s)
 270 {
 271         struct dlm_lkb *lkb;
 272         int i, lvblen = r->res_ls->ls_lvblen;
 273         int print_name = 1;
 274         int rv;
 275
 276         lock_rsb(r);
 277
 278         rv = seq_printf(s, "rsb %p %d %x %lx %d %d %u %d ",
 279                         r,
 280                         r->res_nodeid,
 281                         r->res_first_lkid,
 282                         r->res_flags,
 283                         !list_empty(&r->res_root_list),
 284                         !list_empty(&r->res_recover_list),
 285                         r->res_recover_locks_count,
 286                         r->res_length);
 287         if (rv)
 288                 goto out;
 289
 290         for (i = 0; i < r->res_length; i++) {
 291                 if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
 292                         print_name = 0;
 293         }
 294
 295         seq_printf(s, "%s", print_name ? "str " : "hex");
 296
 297         for (i = 0; i < r->res_length; i++) {
 298                 if (print_name)
 299                         seq_printf(s, "%c", r->res_name[i]);
 300                 else
 301                         seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
 302         }
 303         rv = seq_printf(s, "\n");
 304         if (rv)
 305                 goto out;
 306
 307         if (!r->res_lvbptr)
 308                 goto do_locks;
 309
 310         seq_printf(s, "lvb %u %d", r->res_lvbseq, lvblen);
 311
 312         for (i = 0; i < lvblen; i++)
 313                 seq_printf(s, " %02x", (unsigned char)r->res_lvbptr[i]);
 314         rv = seq_printf(s, "\n");
 315         if (rv)
 316                 goto out;
 317
 318  do_locks:
 319         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
 320                 rv = print_format3_lock(s, lkb, 0);
 321                 if (rv)
 322                         goto out;
 323         }
 324
 325         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
 326                 rv = print_format3_lock(s, lkb, 0);
 327                 if (rv)
 328                         goto out;
 329         }
 330
 331         list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
 332                 rv = print_format3_lock(s, lkb, 0);
 333                 if (rv)
 334                         goto out;
 335         }
 336
 337         list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup) {
 338                 rv = print_format3_lock(s, lkb, 1);
 339                 if (rv)
 340                         goto out;
 341         }
 342  out:
 343         unlock_rsb(r);
 344         return rv;
 345 }
 346
 347 static int print_format4(struct dlm_rsb *r, struct seq_file *s)
 348 {
 349         int our_nodeid = dlm_our_nodeid();
 350         int print_name = 1;
 351         int i, rv;
 352
 353         lock_rsb(r);
 354
 355         rv = seq_printf(s, "rsb %p %d %d %d %d %lu %lx %d ",
 356                         r,
 357                         r->res_nodeid,
 358                         r->res_master_nodeid,
 359                         r->res_dir_nodeid,
 360                         our_nodeid,
 361                         r->res_toss_time,
 362                         r->res_flags,
 363                         r->res_length);
 364         if (rv)
 365                 goto out;
 366
 367         for (i = 0; i < r->res_length; i++) {
 368                 if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
 369                         print_name = 0;
 370         }
 371
 372         seq_printf(s, "%s", print_name ? "str " : "hex");
 373
 374         for (i = 0; i < r->res_length; i++) {
 375                 if (print_name)
 376                         seq_printf(s, "%c", r->res_name[i]);
 377                 else
 378                         seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
 379         }
 380         rv = seq_printf(s, "\n");
 381  out:
 382         unlock_rsb(r);
 383         return rv;
 384 }
 385
 386 struct rsbtbl_iter {
 387         struct dlm_rsb *rsb;
 388         unsigned bucket;
 389         int format;
 390         int header;
 391 };
 392
 393 /* seq_printf returns -1 if the buffer is full, and 0 otherwise.
 394    If the buffer is full, seq_printf can be called again, but it
 395    does nothing and just returns -1.  So, the these printing routines
 396    periodically check the return value to avoid wasting too much time
 397    trying to print to a full buffer. */
 398
 399 static int table_seq_show(struct seq_file *seq, void *iter_ptr)
 400 {
 401         struct rsbtbl_iter *ri = iter_ptr;
 402         int rv = 0;
 403
 404         switch (ri->format) {
 405         case 1:
 406                 rv = print_format1(ri->rsb, seq);
 407                 break;
 408         case 2:
 409                 if (ri->header) {
 410                         seq_printf(seq, "id nodeid remid pid xid exflags "
 411                                         "flags sts grmode rqmode time_ms "
 412                                         "r_nodeid r_len r_name\n");
 413                         ri->header = 0;
 414                 }
 415                 rv = print_format2(ri->rsb, seq);
 416                 break;
 417         case 3:
 418                 if (ri->header) {
 419                         seq_printf(seq, "version rsb 1.1 lvb 1.1 lkb 1.1\n");
 420                         ri->header = 0;
 421                 }
 422                 rv = print_format3(ri->rsb, seq);
 423                 break;
 424         case 4:
 425                 if (ri->header) {
 426                         seq_printf(seq, "version 4 rsb 2\n");
 427                         ri->header = 0;
 428                 }
 429                 rv = print_format4(ri->rsb, seq);
 430                 break;
 431         }
 432
 433         return rv;
 434 }
 435
 436 static const struct seq_operations format1_seq_ops;
 437 static const struct seq_operations format2_seq_ops;
 438 static const struct seq_operations format3_seq_ops;
 439 static const struct seq_operations format4_seq_ops;
 440
 441 static void *table_seq_start(struct seq_file *seq, loff_t *pos)
 442 {
 443         struct rb_root *tree;
 444         struct rb_node *node;
 445         struct dlm_ls *ls = seq->private;
 446         struct rsbtbl_iter *ri;
 447         struct dlm_rsb *r;
 448         loff_t n = *pos;
 449         unsigned bucket, entry;
 450         int toss = (seq->op == &format4_seq_ops);
 451
 452         bucket = n >> 32;
 453         entry = n & ((1LL << 32) - 1);
 454
 455         if (bucket >= ls->ls_rsbtbl_size)
 456                 return NULL;
 457
 458         ri = kzalloc(sizeof(struct rsbtbl_iter), GFP_NOFS);
 459         if (!ri)
 460                 return NULL;
 461         if (n == 0)
 462                 ri->header = 1;
 463         if (seq->op == &format1_seq_ops)
 464                 ri->format = 1;
 465         if (seq->op == &format2_seq_ops)
 466                 ri->format = 2;
 467         if (seq->op == &format3_seq_ops)
 468                 ri->format = 3;
 469         if (seq->op == &format4_seq_ops)
 470                 ri->format = 4;
 471
 472         tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 473
 474         spin_lock(&ls->ls_rsbtbl[bucket].lock);
 475         if (!RB_EMPTY_ROOT(tree)) {
 476                 for (node = rb_first(tree); node; node = rb_next(node)) {
 477                         r = rb_entry(node, struct dlm_rsb, res_hashnode);
 478                         if (!entry--) {
 479                                 dlm_hold_rsb(r);
 480                                 ri->rsb = r;
 481                                 ri->bucket = bucket;
 482                                 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 483                                 return ri;
 484                         }
 485                 }
 486         }
 487         spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 488
 489         /*
 490          * move to the first rsb in the next non-empty bucket
 491          */
 492
 493         /* zero the entry */
 494         n &= ~((1LL << 32) - 1);
 495
 496         while (1) {
 497                 bucket++;
 498                 n += 1LL << 32;
 499
 500                 if (bucket >= ls->ls_rsbtbl_size) {
 501                         kfree(ri);
 502                         return NULL;
 503                 }
 504                 tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 505
 506                 spin_lock(&ls->ls_rsbtbl[bucket].lock);
 507                 if (!RB_EMPTY_ROOT(tree)) {
 508                         node = rb_first(tree);
 509                         r = rb_entry(node, struct dlm_rsb, res_hashnode);
 510                         dlm_hold_rsb(r);
 511                         ri->rsb = r;
 512                         ri->bucket = bucket;
 513                         spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 514                         *pos = n;
 515                         return ri;
 516                 }
 517                 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 518         }
 519 }
 520
 521 static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
 522 {
 523         struct dlm_ls *ls = seq->private;
 524         struct rsbtbl_iter *ri = iter_ptr;
 525         struct rb_root *tree;
 526         struct rb_node *next;
 527         struct dlm_rsb *r, *rp;
 528         loff_t n = *pos;
 529         unsigned bucket;
 530         int toss = (seq->op == &format4_seq_ops);
 531
 532         bucket = n >> 32;
 533
 534         /*
 535          * move to the next rsb in the same bucket
 536          */
 537
 538         spin_lock(&ls->ls_rsbtbl[bucket].lock);
 539         rp = ri->rsb;
 540         next = rb_next(&rp->res_hashnode);
 541
 542         if (next) {
 543                 r = rb_entry(next, struct dlm_rsb, res_hashnode);
 544                 dlm_hold_rsb(r);
 545                 ri->rsb = r;
 546                 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 547                 dlm_put_rsb(rp);
 548                 ++*pos;
 549                 return ri;
 550         }
 551         spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 552         dlm_put_rsb(rp);
 553
 554         /*
 555          * move to the first rsb in the next non-empty bucket
 556          */
 557
 558         /* zero the entry */
 559         n &= ~((1LL << 32) - 1);
 560
 561         while (1) {
 562                 bucket++;
 563                 n += 1LL << 32;
 564
 565                 if (bucket >= ls->ls_rsbtbl_size) {
 566                         kfree(ri);
 567                         return NULL;
 568                 }
 569                 tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 570
 571                 spin_lock(&ls->ls_rsbtbl[bucket].lock);
 572                 if (!RB_EMPTY_ROOT(tree)) {
 573                         next = rb_first(tree);
 574                         r = rb_entry(next, struct dlm_rsb, res_hashnode);
 575                         dlm_hold_rsb(r);
 576                         ri->rsb = r;
 577                         ri->bucket = bucket;
 578                         spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 579                         *pos = n;
 580                         return ri;
 581                 }
 582                 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 583         }
 584 }
 585
 586 static void table_seq_stop(struct seq_file *seq, void *iter_ptr)
 587 {
 588         struct rsbtbl_iter *ri = iter_ptr;
 589
 590         if (ri) {
 591                 dlm_put_rsb(ri->rsb);
 592                 kfree(ri);
 593         }
 594 }
 595
 596 static const struct seq_operations format1_seq_ops = {
 597         .start = table_seq_start,
 598         .next  = table_seq_next,
 599         .stop  = table_seq_stop,
 600         .show  = table_seq_show,
 601 };
 602
 603 static const struct seq_operations format2_seq_ops = {
 604         .start = table_seq_start,
 605         .next  = table_seq_next,
 606         .stop  = table_seq_stop,
 607         .show  = table_seq_show,
 608 };
 609
 610 static const struct seq_operations format3_seq_ops = {
 611         .start = table_seq_start,
 612         .next  = table_seq_next,
 613         .stop  = table_seq_stop,
 614         .show  = table_seq_show,
 615 };
 616
 617 static const struct seq_operations format4_seq_ops = {
 618         .start = table_seq_start,
 619         .next  = table_seq_next,
 620         .stop  = table_seq_stop,
 621         .show  = table_seq_show,
 622 };
 623
 624 static const struct file_operations format1_fops;
 625 static const struct file_operations format2_fops;
 626 static const struct file_operations format3_fops;
 627 static const struct file_operations format4_fops;
 628
 629 static int table_open(struct inode *inode, struct file *file)
 630 {
 631         struct seq_file *seq;
 632         int ret = -1;
 633
 634         if (file->f_op == &format1_fops)
 635                 ret = seq_open(file, &format1_seq_ops);
 636         else if (file->f_op == &format2_fops)
 637                 ret = seq_open(file, &format2_seq_ops);
 638         else if (file->f_op == &format3_fops)
 639                 ret = seq_open(file, &format3_seq_ops);
 640         else if (file->f_op == &format4_fops)
 641                 ret = seq_open(file, &format4_seq_ops);
 642
 643         if (ret)
 644                 return ret;
 645
 646         seq = file->private_data;
 647         seq->private = inode->i_private; /* the dlm_ls */
 648         return 0;
 649 }
 650
 651 static const struct file_operations format1_fops = {
 652         .owner   = THIS_MODULE,
 653         .open    = table_open,
 654         .read    = seq_read,
 655         .llseek  = seq_lseek,
 656         .release = seq_release
 657 };
 658
 659 static const struct file_operations format2_fops = {
 660         .owner   = THIS_MODULE,
 661         .open    = table_open,
 662         .read    = seq_read,
 663         .llseek  = seq_lseek,
 664         .release = seq_release
 665 };
 666
 667 static const struct file_operations format3_fops = {
 668         .owner   = THIS_MODULE,
 669         .open    = table_open,
 670         .read    = seq_read,
 671         .llseek  = seq_lseek,
 672         .release = seq_release
 673 };
 674
 675 static const struct file_operations format4_fops = {
 676         .owner   = THIS_MODULE,
 677         .open    = table_open,
 678         .read    = seq_read,
 679         .llseek  = seq_lseek,
 680         .release = seq_release
 681 };
 682
 683 /*
 684  * dump lkb's on the ls_waiters list
 685  */
 686 static ssize_t waiters_read(struct file *file, char __user *userbuf,
 687                             size_t count, loff_t *ppos)
 688 {
 689         struct dlm_ls *ls = file->private_data;
 690         struct dlm_lkb *lkb;
 691         size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
 692
 693         mutex_lock(&debug_buf_lock);
 694         mutex_lock(&ls->ls_waiters_mutex);
 695         memset(debug_buf, 0, sizeof(debug_buf));
 696
 697         list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
 698                 ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
 699                                lkb->lkb_id, lkb->lkb_wait_type,
 700                                lkb->lkb_nodeid, lkb->lkb_resource->res_name);
 701                 if (ret >= len - pos)
 702                         break;
 703                 pos += ret;
 704         }
 705         mutex_unlock(&ls->ls_waiters_mutex);
 706
 707         rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
 708         mutex_unlock(&debug_buf_lock);
 709         return rv;
 710 }
 711
 712 static const struct file_operations waiters_fops = {
 713         .owner   = THIS_MODULE,
 714         .open    = simple_open,
 715         .read    = waiters_read,
 716         .llseek  = default_llseek,
 717 };
 718
 719 void dlm_delete_debug_file(struct dlm_ls *ls)
 720 {
 721         if (ls->ls_debug_rsb_dentry)
 722                 debugfs_remove(ls->ls_debug_rsb_dentry);
 723         if (ls->ls_debug_waiters_dentry)
 724                 debugfs_remove(ls->ls_debug_waiters_dentry);
 725         if (ls->ls_debug_locks_dentry)
 726                 debugfs_remove(ls->ls_debug_locks_dentry);
 727         if (ls->ls_debug_all_dentry)
 728                 debugfs_remove(ls->ls_debug_all_dentry);
 729         if (ls->ls_debug_toss_dentry)
 730                 debugfs_remove(ls->ls_debug_toss_dentry);
 731 }
 732
 733 int dlm_create_debug_file(struct dlm_ls *ls)
 734 {
 735         char name[DLM_LOCKSPACE_LEN+8];
 736
 737         /* format 1 */
 738
 739         ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
 740                                                       S_IFREG | S_IRUGO,
 741                                                       dlm_root,
 742                                                       ls,
 743                                                       &format1_fops);
 744         if (!ls->ls_debug_rsb_dentry)
 745                 goto fail;
 746
 747         /* format 2 */
 748
 749         memset(name, 0, sizeof(name));
 750         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_locks", ls->ls_name);
 751
 752         ls->ls_debug_locks_dentry = debugfs_create_file(name,
 753                                                         S_IFREG | S_IRUGO,
 754                                                         dlm_root,
 755                                                         ls,
 756                                                         &format2_fops);
 757         if (!ls->ls_debug_locks_dentry)
 758                 goto fail;
 759
 760         /* format 3 */
 761
 762         memset(name, 0, sizeof(name));
 763         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_all", ls->ls_name);
 764
 765         ls->ls_debug_all_dentry = debugfs_create_file(name,
 766                                                       S_IFREG | S_IRUGO,
 767                                                       dlm_root,
 768                                                       ls,
 769                                                       &format3_fops);
 770         if (!ls->ls_debug_all_dentry)
 771                 goto fail;
 772
 773         /* format 4 */
 774
 775         memset(name, 0, sizeof(name));
 776         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_toss", ls->ls_name);
 777
 778         ls->ls_debug_toss_dentry = debugfs_create_file(name,
 779                                                        S_IFREG | S_IRUGO,
 780                                                        dlm_root,
 781                                                        ls,
 782                                                        &format4_fops);
 783         if (!ls->ls_debug_toss_dentry)
 784                 goto fail;
 785
 786         memset(name, 0, sizeof(name));
 787         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
 788
 789         ls->ls_debug_waiters_dentry = debugfs_create_file(name,
 790                                                           S_IFREG | S_IRUGO,
 791                                                           dlm_root,
 792                                                           ls,
 793                                                           &waiters_fops);
 794         if (!ls->ls_debug_waiters_dentry)
 795                 goto fail;
 796
 797         return 0;
 798
 799  fail:
 800         dlm_delete_debug_file(ls);
 801         return -ENOMEM;
 802 }
 803
 804 int __init dlm_register_debugfs(void)
 805 {
 806         mutex_init(&debug_buf_lock);
 807         dlm_root = debugfs_create_dir("dlm", NULL);
 808         return dlm_root ? 0 : -ENOMEM;
 809 }
 810
 811 void dlm_unregister_debugfs(void)
 812 {
 813         debugfs_remove(dlm_root);
 814 }
 815