fs/dlm/debug_fs.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) 2005 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
  19 #include "dlm_internal.h"
  20 #include "lock.h"
  21
  22 #define DLM_DEBUG_BUF_LEN 4096
  23 static char debug_buf[DLM_DEBUG_BUF_LEN];
  24 static struct mutex debug_buf_lock;
  25
  26 static struct dentry *dlm_root;
  27
  28 struct rsb_iter {
  29         int entry;
  30         int locks;
  31         int header;
  32         struct dlm_ls *ls;
  33         struct list_head *next;
  34         struct dlm_rsb *rsb;
  35 };
  36
  37 /*
  38  * dump all rsb's in the lockspace hash table
  39  */
  40
  41 static char *print_lockmode(int mode)
  42 {
  43         switch (mode) {
  44         case DLM_LOCK_IV:
  45                 return "--";
  46         case DLM_LOCK_NL:
  47                 return "NL";
  48         case DLM_LOCK_CR:
  49                 return "CR";
  50         case DLM_LOCK_CW:
  51                 return "CW";
  52         case DLM_LOCK_PR:
  53                 return "PR";
  54         case DLM_LOCK_PW:
  55                 return "PW";
  56         case DLM_LOCK_EX:
  57                 return "EX";
  58         default:
  59                 return "??";
  60         }
  61 }
  62
  63 static void print_resource_lock(struct seq_file *s, struct dlm_lkb *lkb,
  64                                 struct dlm_rsb *res)
  65 {
  66         seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
  67
  68         if (lkb->lkb_status == DLM_LKSTS_CONVERT
  69             || lkb->lkb_status == DLM_LKSTS_WAITING)
  70                 seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
  71
  72         if (lkb->lkb_nodeid) {
  73                 if (lkb->lkb_nodeid != res->res_nodeid)
  74                         seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
  75                                    lkb->lkb_remid);
  76                 else
  77                         seq_printf(s, " Master:     %08x", lkb->lkb_remid);
  78         }
  79
  80         if (lkb->lkb_wait_type)
  81                 seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
  82
  83         seq_printf(s, "\n");
  84 }
  85
  86 static int print_resource(struct dlm_rsb *res, struct seq_file *s)
  87 {
  88         struct dlm_lkb *lkb;
  89         int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
  90
  91         lock_rsb(res);
  92
  93         seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
  94         for (i = 0; i < res->res_length; i++) {
  95                 if (isprint(res->res_name[i]))
  96                         seq_printf(s, "%c", res->res_name[i]);
  97                 else
  98                         seq_printf(s, "%c", '.');
  99         }
 100         if (res->res_nodeid > 0)
 101                 seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
 102                            res->res_nodeid);
 103         else if (res->res_nodeid == 0)
 104                 seq_printf(s, "\"  \nMaster Copy\n");
 105         else if (res->res_nodeid == -1)
 106                 seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
 107                            res->res_first_lkid);
 108         else
 109                 seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
 110
 111         /* Print the LVB: */
 112         if (res->res_lvbptr) {
 113                 seq_printf(s, "LVB: ");
 114                 for (i = 0; i < lvblen; i++) {
 115                         if (i == lvblen / 2)
 116                                 seq_printf(s, "\n     ");
 117                         seq_printf(s, "%02x ",
 118                                    (unsigned char) res->res_lvbptr[i]);
 119                 }
 120                 if (rsb_flag(res, RSB_VALNOTVALID))
 121                         seq_printf(s, " (INVALID)");
 122                 seq_printf(s, "\n");
 123         }
 124
 125         root_list = !list_empty(&res->res_root_list);
 126         recover_list = !list_empty(&res->res_recover_list);
 127
 128         if (root_list || recover_list) {
 129                 seq_printf(s, "Recovery: root %d recover %d flags %lx "
 130                            "count %d\n", root_list, recover_list,
 131                            res->res_flags, res->res_recover_locks_count);
 132         }
 133
 134         /* Print the locks attached to this resource */
 135         seq_printf(s, "Granted Queue\n");
 136         list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
 137                 print_resource_lock(s, lkb, res);
 138
 139         seq_printf(s, "Conversion Queue\n");
 140         list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
 141                 print_resource_lock(s, lkb, res);
 142
 143         seq_printf(s, "Waiting Queue\n");
 144         list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
 145                 print_resource_lock(s, lkb, res);
 146
 147         if (list_empty(&res->res_lookup))
 148                 goto out;
 149
 150         seq_printf(s, "Lookup Queue\n");
 151         list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
 152                 seq_printf(s, "%08x %s", lkb->lkb_id,
 153                            print_lockmode(lkb->lkb_rqmode));
 154                 if (lkb->lkb_wait_type)
 155                         seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
 156                 seq_printf(s, "\n");
 157         }
 158  out:
 159         unlock_rsb(res);
 160         return 0;
 161 }
 162
 163 static void print_lock(struct seq_file *s, struct dlm_lkb *lkb, struct dlm_rsb *r)
 164 {
 165         struct dlm_user_args *ua;
 166         unsigned int waiting = 0;
 167         uint64_t xid = 0;
 168
 169         if (lkb->lkb_flags & DLM_IFL_USER) {
 170                 ua = (struct dlm_user_args *) lkb->lkb_astparam;
 171                 if (ua)
 172                         xid = ua->xid;
 173         }
 174
 175         if (lkb->lkb_timestamp)
 176                 waiting = jiffies_to_msecs(jiffies - lkb->lkb_timestamp);
 177
 178         /* id nodeid remid pid xid exflags flags sts grmode rqmode time_ms
 179            r_nodeid r_len r_name */
 180
 181         seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %u %u %d \"%s\"\n",
 182                    lkb->lkb_id,
 183                    lkb->lkb_nodeid,
 184                    lkb->lkb_remid,
 185                    lkb->lkb_ownpid,
 186                    (unsigned long long)xid,
 187                    lkb->lkb_exflags,
 188                    lkb->lkb_flags,
 189                    lkb->lkb_status,
 190                    lkb->lkb_grmode,
 191                    lkb->lkb_rqmode,
 192                    waiting,
 193                    r->res_nodeid,
 194                    r->res_length,
 195                    r->res_name);
 196 }
 197
 198 static int print_locks(struct dlm_rsb *r, struct seq_file *s)
 199 {
 200         struct dlm_lkb *lkb;
 201
 202         lock_rsb(r);
 203
 204         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
 205                 print_lock(s, lkb, r);
 206
 207         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
 208                 print_lock(s, lkb, r);
 209
 210         list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
 211                 print_lock(s, lkb, r);
 212
 213         unlock_rsb(r);
 214         return 0;
 215 }
 216
 217 static int rsb_iter_next(struct rsb_iter *ri)
 218 {
 219         struct dlm_ls *ls = ri->ls;
 220         int i;
 221
 222         if (!ri->next) {
 223  top:
 224                 /* Find the next non-empty hash bucket */
 225                 for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
 226                         read_lock(&ls->ls_rsbtbl[i].lock);
 227                         if (!list_empty(&ls->ls_rsbtbl[i].list)) {
 228                                 ri->next = ls->ls_rsbtbl[i].list.next;
 229                                 ri->rsb = list_entry(ri->next, struct dlm_rsb,
 230                                                         res_hashchain);
 231                                 dlm_hold_rsb(ri->rsb);
 232                                 read_unlock(&ls->ls_rsbtbl[i].lock);
 233                                 break;
 234                         }
 235                         read_unlock(&ls->ls_rsbtbl[i].lock);
 236                 }
 237                 ri->entry = i;
 238
 239                 if (ri->entry >= ls->ls_rsbtbl_size)
 240                         return 1;
 241         } else {
 242                 struct dlm_rsb *old = ri->rsb;
 243                 i = ri->entry;
 244                 read_lock(&ls->ls_rsbtbl[i].lock);
 245                 ri->next = ri->next->next;
 246                 if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
 247                         /* End of list - move to next bucket */
 248                         ri->next = NULL;
 249                         ri->entry++;
 250                         read_unlock(&ls->ls_rsbtbl[i].lock);
 251                         dlm_put_rsb(old);
 252                         goto top;
 253                 }
 254                 ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
 255                 dlm_hold_rsb(ri->rsb);
 256                 read_unlock(&ls->ls_rsbtbl[i].lock);
 257                 dlm_put_rsb(old);
 258         }
 259
 260         return 0;
 261 }
 262
 263 static void rsb_iter_free(struct rsb_iter *ri)
 264 {
 265         kfree(ri);
 266 }
 267
 268 static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
 269 {
 270         struct rsb_iter *ri;
 271
 272         ri = kzalloc(sizeof *ri, GFP_KERNEL);
 273         if (!ri)
 274                 return NULL;
 275
 276         ri->ls = ls;
 277         ri->entry = 0;
 278         ri->next = NULL;
 279
 280         if (rsb_iter_next(ri)) {
 281                 rsb_iter_free(ri);
 282                 return NULL;
 283         }
 284
 285         return ri;
 286 }
 287
 288 static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
 289 {
 290         struct rsb_iter *ri;
 291         loff_t n = *pos;
 292
 293         ri = rsb_iter_init(file->private);
 294         if (!ri)
 295                 return NULL;
 296
 297         while (n--) {
 298                 if (rsb_iter_next(ri)) {
 299                         rsb_iter_free(ri);
 300                         return NULL;
 301                 }
 302         }
 303
 304         return ri;
 305 }
 306
 307 static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
 308 {
 309         struct rsb_iter *ri = iter_ptr;
 310
 311         (*pos)++;
 312
 313         if (rsb_iter_next(ri)) {
 314                 rsb_iter_free(ri);
 315                 return NULL;
 316         }
 317
 318         return ri;
 319 }
 320
 321 static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
 322 {
 323         /* nothing for now */
 324 }
 325
 326 static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
 327 {
 328         struct rsb_iter *ri = iter_ptr;
 329
 330         if (ri->locks) {
 331                 if (ri->header) {
 332                         seq_printf(file, "id nodeid remid pid xid exflags flags "
 333                                          "sts grmode rqmode time_ms r_nodeid "
 334                                          "r_len r_name\n");
 335                         ri->header = 0;
 336                 }
 337                 print_locks(ri->rsb, file);
 338         } else {
 339                 print_resource(ri->rsb, file);
 340         }
 341
 342         return 0;
 343 }
 344
 345 static struct seq_operations rsb_seq_ops = {
 346         .start = rsb_seq_start,
 347         .next  = rsb_seq_next,
 348         .stop  = rsb_seq_stop,
 349         .show  = rsb_seq_show,
 350 };
 351
 352 static int rsb_open(struct inode *inode, struct file *file)
 353 {
 354         struct seq_file *seq;
 355         int ret;
 356
 357         ret = seq_open(file, &rsb_seq_ops);
 358         if (ret)
 359                 return ret;
 360
 361         seq = file->private_data;
 362         seq->private = inode->i_private;
 363
 364         return 0;
 365 }
 366
 367 static const struct file_operations rsb_fops = {
 368         .owner   = THIS_MODULE,
 369         .open    = rsb_open,
 370         .read    = seq_read,
 371         .llseek  = seq_lseek,
 372         .release = seq_release
 373 };
 374
 375 /*
 376  * Dump state in compact per-lock listing
 377  */
 378
 379 static struct rsb_iter *locks_iter_init(struct dlm_ls *ls, loff_t *pos)
 380 {
 381         struct rsb_iter *ri;
 382
 383         ri = kzalloc(sizeof *ri, GFP_KERNEL);
 384         if (!ri)
 385                 return NULL;
 386
 387         ri->ls = ls;
 388         ri->entry = 0;
 389         ri->next = NULL;
 390         ri->locks = 1;
 391
 392         if (*pos == 0)
 393                 ri->header = 1;
 394
 395         if (rsb_iter_next(ri)) {
 396                 rsb_iter_free(ri);
 397                 return NULL;
 398         }
 399
 400         return ri;
 401 }
 402
 403 static void *locks_seq_start(struct seq_file *file, loff_t *pos)
 404 {
 405         struct rsb_iter *ri;
 406         loff_t n = *pos;
 407
 408         ri = locks_iter_init(file->private, pos);
 409         if (!ri)
 410                 return NULL;
 411
 412         while (n--) {
 413                 if (rsb_iter_next(ri)) {
 414                         rsb_iter_free(ri);
 415                         return NULL;
 416                 }
 417         }
 418
 419         return ri;
 420 }
 421
 422 static struct seq_operations locks_seq_ops = {
 423         .start = locks_seq_start,
 424         .next  = rsb_seq_next,
 425         .stop  = rsb_seq_stop,
 426         .show  = rsb_seq_show,
 427 };
 428
 429 static int locks_open(struct inode *inode, struct file *file)
 430 {
 431         struct seq_file *seq;
 432         int ret;
 433
 434         ret = seq_open(file, &locks_seq_ops);
 435         if (ret)
 436                 return ret;
 437
 438         seq = file->private_data;
 439         seq->private = inode->i_private;
 440
 441         return 0;
 442 }
 443
 444 static const struct file_operations locks_fops = {
 445         .owner   = THIS_MODULE,
 446         .open    = locks_open,
 447         .read    = seq_read,
 448         .llseek  = seq_lseek,
 449         .release = seq_release
 450 };
 451
 452 /*
 453  * dump lkb's on the ls_waiters list
 454  */
 455
 456 static int waiters_open(struct inode *inode, struct file *file)
 457 {
 458         file->private_data = inode->i_private;
 459         return 0;
 460 }
 461
 462 static ssize_t waiters_read(struct file *file, char __user *userbuf,
 463                             size_t count, loff_t *ppos)
 464 {
 465         struct dlm_ls *ls = file->private_data;
 466         struct dlm_lkb *lkb;
 467         size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
 468
 469         mutex_lock(&debug_buf_lock);
 470         mutex_lock(&ls->ls_waiters_mutex);
 471         memset(debug_buf, 0, sizeof(debug_buf));
 472
 473         list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
 474                 ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
 475                                lkb->lkb_id, lkb->lkb_wait_type,
 476                                lkb->lkb_nodeid, lkb->lkb_resource->res_name);
 477                 if (ret >= len - pos)
 478                         break;
 479                 pos += ret;
 480         }
 481         mutex_unlock(&ls->ls_waiters_mutex);
 482
 483         rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
 484         mutex_unlock(&debug_buf_lock);
 485         return rv;
 486 }
 487
 488 static const struct file_operations waiters_fops = {
 489         .owner   = THIS_MODULE,
 490         .open    = waiters_open,
 491         .read    = waiters_read
 492 };
 493
 494 int dlm_create_debug_file(struct dlm_ls *ls)
 495 {
 496         char name[DLM_LOCKSPACE_LEN+8];
 497
 498         ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
 499                                                       S_IFREG | S_IRUGO,
 500                                                       dlm_root,
 501                                                       ls,
 502                                                       &rsb_fops);
 503         if (!ls->ls_debug_rsb_dentry)
 504                 return -ENOMEM;
 505
 506         memset(name, 0, sizeof(name));
 507         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
 508
 509         ls->ls_debug_waiters_dentry = debugfs_create_file(name,
 510                                                           S_IFREG | S_IRUGO,
 511                                                           dlm_root,
 512                                                           ls,
 513                                                           &waiters_fops);
 514         if (!ls->ls_debug_waiters_dentry) {
 515                 debugfs_remove(ls->ls_debug_rsb_dentry);
 516                 return -ENOMEM;
 517         }
 518
 519         memset(name, 0, sizeof(name));
 520         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_locks", ls->ls_name);
 521
 522         ls->ls_debug_locks_dentry = debugfs_create_file(name,
 523                                                         S_IFREG | S_IRUGO,
 524                                                         dlm_root,
 525                                                         ls,
 526                                                         &locks_fops);
 527         if (!ls->ls_debug_locks_dentry) {
 528                 debugfs_remove(ls->ls_debug_waiters_dentry);
 529                 debugfs_remove(ls->ls_debug_rsb_dentry);
 530                 return -ENOMEM;
 531         }
 532
 533         return 0;
 534 }
 535
 536 void dlm_delete_debug_file(struct dlm_ls *ls)
 537 {
 538         if (ls->ls_debug_rsb_dentry)
 539                 debugfs_remove(ls->ls_debug_rsb_dentry);
 540         if (ls->ls_debug_waiters_dentry)
 541                 debugfs_remove(ls->ls_debug_waiters_dentry);
 542         if (ls->ls_debug_locks_dentry)
 543                 debugfs_remove(ls->ls_debug_locks_dentry);
 544 }
 545
 546 int dlm_register_debugfs(void)
 547 {
 548         mutex_init(&debug_buf_lock);
 549         dlm_root = debugfs_create_dir("dlm", NULL);
 550         return dlm_root ? 0 : -ENOMEM;
 551 }
 552
 553 void dlm_unregister_debugfs(void)
 554 {
 555         debugfs_remove(dlm_root);
 556 }
 557