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         unsigned int waiting = 0;
 166         uint64_t xid = 0;
 167
 168         if (lkb->lkb_flags & DLM_IFL_USER) {
 169                 if (lkb->lkb_ua)
 170                         xid = lkb->lkb_ua->xid;
 171         }
 172
 173         if (lkb->lkb_timestamp)
 174                 waiting = jiffies_to_msecs(jiffies - lkb->lkb_timestamp);
 175
 176         /* id nodeid remid pid xid exflags flags sts grmode rqmode time_ms
 177            r_nodeid r_len r_name */
 178
 179         seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %u %u %d \"%s\"\n",
 180                    lkb->lkb_id,
 181                    lkb->lkb_nodeid,
 182                    lkb->lkb_remid,
 183                    lkb->lkb_ownpid,
 184                    (unsigned long long)xid,
 185                    lkb->lkb_exflags,
 186                    lkb->lkb_flags,
 187                    lkb->lkb_status,
 188                    lkb->lkb_grmode,
 189                    lkb->lkb_rqmode,
 190                    waiting,
 191                    r->res_nodeid,
 192                    r->res_length,
 193                    r->res_name);
 194 }
 195
 196 static int print_locks(struct dlm_rsb *r, struct seq_file *s)
 197 {
 198         struct dlm_lkb *lkb;
 199
 200         lock_rsb(r);
 201
 202         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
 203                 print_lock(s, lkb, r);
 204
 205         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
 206                 print_lock(s, lkb, r);
 207
 208         list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
 209                 print_lock(s, lkb, r);
 210
 211         unlock_rsb(r);
 212         return 0;
 213 }
 214
 215 static int rsb_iter_next(struct rsb_iter *ri)
 216 {
 217         struct dlm_ls *ls = ri->ls;
 218         int i;
 219
 220         if (!ri->next) {
 221  top:
 222                 /* Find the next non-empty hash bucket */
 223                 for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
 224                         read_lock(&ls->ls_rsbtbl[i].lock);
 225                         if (!list_empty(&ls->ls_rsbtbl[i].list)) {
 226                                 ri->next = ls->ls_rsbtbl[i].list.next;
 227                                 ri->rsb = list_entry(ri->next, struct dlm_rsb,
 228                                                         res_hashchain);
 229                                 dlm_hold_rsb(ri->rsb);
 230                                 read_unlock(&ls->ls_rsbtbl[i].lock);
 231                                 break;
 232                         }
 233                         read_unlock(&ls->ls_rsbtbl[i].lock);
 234                 }
 235                 ri->entry = i;
 236
 237                 if (ri->entry >= ls->ls_rsbtbl_size)
 238                         return 1;
 239         } else {
 240                 struct dlm_rsb *old = ri->rsb;
 241                 i = ri->entry;
 242                 read_lock(&ls->ls_rsbtbl[i].lock);
 243                 ri->next = ri->next->next;
 244                 if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
 245                         /* End of list - move to next bucket */
 246                         ri->next = NULL;
 247                         ri->entry++;
 248                         read_unlock(&ls->ls_rsbtbl[i].lock);
 249                         dlm_put_rsb(old);
 250                         goto top;
 251                 }
 252                 ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
 253                 dlm_hold_rsb(ri->rsb);
 254                 read_unlock(&ls->ls_rsbtbl[i].lock);
 255                 dlm_put_rsb(old);
 256         }
 257
 258         return 0;
 259 }
 260
 261 static void rsb_iter_free(struct rsb_iter *ri)
 262 {
 263         kfree(ri);
 264 }
 265
 266 static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
 267 {
 268         struct rsb_iter *ri;
 269
 270         ri = kzalloc(sizeof *ri, GFP_KERNEL);
 271         if (!ri)
 272                 return NULL;
 273
 274         ri->ls = ls;
 275         ri->entry = 0;
 276         ri->next = NULL;
 277
 278         if (rsb_iter_next(ri)) {
 279                 rsb_iter_free(ri);
 280                 return NULL;
 281         }
 282
 283         return ri;
 284 }
 285
 286 static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
 287 {
 288         struct rsb_iter *ri;
 289         loff_t n = *pos;
 290
 291         ri = rsb_iter_init(file->private);
 292         if (!ri)
 293                 return NULL;
 294
 295         while (n--) {
 296                 if (rsb_iter_next(ri)) {
 297                         rsb_iter_free(ri);
 298                         return NULL;
 299                 }
 300         }
 301
 302         return ri;
 303 }
 304
 305 static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
 306 {
 307         struct rsb_iter *ri = iter_ptr;
 308
 309         (*pos)++;
 310
 311         if (rsb_iter_next(ri)) {
 312                 rsb_iter_free(ri);
 313                 return NULL;
 314         }
 315
 316         return ri;
 317 }
 318
 319 static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
 320 {
 321         /* nothing for now */
 322 }
 323
 324 static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
 325 {
 326         struct rsb_iter *ri = iter_ptr;
 327
 328         if (ri->locks) {
 329                 if (ri->header) {
 330                         seq_printf(file, "id nodeid remid pid xid exflags flags "
 331                                          "sts grmode rqmode time_ms r_nodeid "
 332                                          "r_len r_name\n");
 333                         ri->header = 0;
 334                 }
 335                 print_locks(ri->rsb, file);
 336         } else {
 337                 print_resource(ri->rsb, file);
 338         }
 339
 340         return 0;
 341 }
 342
 343 static struct seq_operations rsb_seq_ops = {
 344         .start = rsb_seq_start,
 345         .next  = rsb_seq_next,
 346         .stop  = rsb_seq_stop,
 347         .show  = rsb_seq_show,
 348 };
 349
 350 static int rsb_open(struct inode *inode, struct file *file)
 351 {
 352         struct seq_file *seq;
 353         int ret;
 354
 355         ret = seq_open(file, &rsb_seq_ops);
 356         if (ret)
 357                 return ret;
 358
 359         seq = file->private_data;
 360         seq->private = inode->i_private;
 361
 362         return 0;
 363 }
 364
 365 static const struct file_operations rsb_fops = {
 366         .owner   = THIS_MODULE,
 367         .open    = rsb_open,
 368         .read    = seq_read,
 369         .llseek  = seq_lseek,
 370         .release = seq_release
 371 };
 372
 373 /*
 374  * Dump state in compact per-lock listing
 375  */
 376
 377 static struct rsb_iter *locks_iter_init(struct dlm_ls *ls, loff_t *pos)
 378 {
 379         struct rsb_iter *ri;
 380
 381         ri = kzalloc(sizeof *ri, GFP_KERNEL);
 382         if (!ri)
 383                 return NULL;
 384
 385         ri->ls = ls;
 386         ri->entry = 0;
 387         ri->next = NULL;
 388         ri->locks = 1;
 389
 390         if (*pos == 0)
 391                 ri->header = 1;
 392
 393         if (rsb_iter_next(ri)) {
 394                 rsb_iter_free(ri);
 395                 return NULL;
 396         }
 397
 398         return ri;
 399 }
 400
 401 static void *locks_seq_start(struct seq_file *file, loff_t *pos)
 402 {
 403         struct rsb_iter *ri;
 404         loff_t n = *pos;
 405
 406         ri = locks_iter_init(file->private, pos);
 407         if (!ri)
 408                 return NULL;
 409
 410         while (n--) {
 411                 if (rsb_iter_next(ri)) {
 412                         rsb_iter_free(ri);
 413                         return NULL;
 414                 }
 415         }
 416
 417         return ri;
 418 }
 419
 420 static struct seq_operations locks_seq_ops = {
 421         .start = locks_seq_start,
 422         .next  = rsb_seq_next,
 423         .stop  = rsb_seq_stop,
 424         .show  = rsb_seq_show,
 425 };
 426
 427 static int locks_open(struct inode *inode, struct file *file)
 428 {
 429         struct seq_file *seq;
 430         int ret;
 431
 432         ret = seq_open(file, &locks_seq_ops);
 433         if (ret)
 434                 return ret;
 435
 436         seq = file->private_data;
 437         seq->private = inode->i_private;
 438
 439         return 0;
 440 }
 441
 442 static const struct file_operations locks_fops = {
 443         .owner   = THIS_MODULE,
 444         .open    = locks_open,
 445         .read    = seq_read,
 446         .llseek  = seq_lseek,
 447         .release = seq_release
 448 };
 449
 450 /*
 451  * dump lkb's on the ls_waiters list
 452  */
 453
 454 static int waiters_open(struct inode *inode, struct file *file)
 455 {
 456         file->private_data = inode->i_private;
 457         return 0;
 458 }
 459
 460 static ssize_t waiters_read(struct file *file, char __user *userbuf,
 461                             size_t count, loff_t *ppos)
 462 {
 463         struct dlm_ls *ls = file->private_data;
 464         struct dlm_lkb *lkb;
 465         size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
 466
 467         mutex_lock(&debug_buf_lock);
 468         mutex_lock(&ls->ls_waiters_mutex);
 469         memset(debug_buf, 0, sizeof(debug_buf));
 470
 471         list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
 472                 ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
 473                                lkb->lkb_id, lkb->lkb_wait_type,
 474                                lkb->lkb_nodeid, lkb->lkb_resource->res_name);
 475                 if (ret >= len - pos)
 476                         break;
 477                 pos += ret;
 478         }
 479         mutex_unlock(&ls->ls_waiters_mutex);
 480
 481         rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
 482         mutex_unlock(&debug_buf_lock);
 483         return rv;
 484 }
 485
 486 static const struct file_operations waiters_fops = {
 487         .owner   = THIS_MODULE,
 488         .open    = waiters_open,
 489         .read    = waiters_read
 490 };
 491
 492 int dlm_create_debug_file(struct dlm_ls *ls)
 493 {
 494         char name[DLM_LOCKSPACE_LEN+8];
 495
 496         ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
 497                                                       S_IFREG | S_IRUGO,
 498                                                       dlm_root,
 499                                                       ls,
 500                                                       &rsb_fops);
 501         if (!ls->ls_debug_rsb_dentry)
 502                 return -ENOMEM;
 503
 504         memset(name, 0, sizeof(name));
 505         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
 506
 507         ls->ls_debug_waiters_dentry = debugfs_create_file(name,
 508                                                           S_IFREG | S_IRUGO,
 509                                                           dlm_root,
 510                                                           ls,
 511                                                           &waiters_fops);
 512         if (!ls->ls_debug_waiters_dentry) {
 513                 debugfs_remove(ls->ls_debug_rsb_dentry);
 514                 return -ENOMEM;
 515         }
 516
 517         memset(name, 0, sizeof(name));
 518         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_locks", ls->ls_name);
 519
 520         ls->ls_debug_locks_dentry = debugfs_create_file(name,
 521                                                         S_IFREG | S_IRUGO,
 522                                                         dlm_root,
 523                                                         ls,
 524                                                         &locks_fops);
 525         if (!ls->ls_debug_locks_dentry) {
 526                 debugfs_remove(ls->ls_debug_waiters_dentry);
 527                 debugfs_remove(ls->ls_debug_rsb_dentry);
 528                 return -ENOMEM;
 529         }
 530
 531         return 0;
 532 }
 533
 534 void dlm_delete_debug_file(struct dlm_ls *ls)
 535 {
 536         if (ls->ls_debug_rsb_dentry)
 537                 debugfs_remove(ls->ls_debug_rsb_dentry);
 538         if (ls->ls_debug_waiters_dentry)
 539                 debugfs_remove(ls->ls_debug_waiters_dentry);
 540         if (ls->ls_debug_locks_dentry)
 541                 debugfs_remove(ls->ls_debug_locks_dentry);
 542 }
 543
 544 int __init dlm_register_debugfs(void)
 545 {
 546         mutex_init(&debug_buf_lock);
 547         dlm_root = debugfs_create_dir("dlm", NULL);
 548         return dlm_root ? 0 : -ENOMEM;
 549 }
 550
 551 void dlm_unregister_debugfs(void)
 552 {
 553         debugfs_remove(dlm_root);
 554 }
 555