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