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         struct dlm_ls *ls;
  31         struct list_head *next;
  32         struct dlm_rsb *rsb;
  33 };
  34
  35 /*
  36  * dump all rsb's in the lockspace hash table
  37  */
  38
  39 static char *print_lockmode(int mode)
  40 {
  41         switch (mode) {
  42         case DLM_LOCK_IV:
  43                 return "--";
  44         case DLM_LOCK_NL:
  45                 return "NL";
  46         case DLM_LOCK_CR:
  47                 return "CR";
  48         case DLM_LOCK_CW:
  49                 return "CW";
  50         case DLM_LOCK_PR:
  51                 return "PR";
  52         case DLM_LOCK_PW:
  53                 return "PW";
  54         case DLM_LOCK_EX:
  55                 return "EX";
  56         default:
  57                 return "??";
  58         }
  59 }
  60
  61 static void print_lock(struct seq_file *s, struct dlm_lkb *lkb,
  62                        struct dlm_rsb *res)
  63 {
  64         seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
  65
  66         if (lkb->lkb_status == DLM_LKSTS_CONVERT
  67             || lkb->lkb_status == DLM_LKSTS_WAITING)
  68                 seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
  69
  70         if (lkb->lkb_nodeid) {
  71                 if (lkb->lkb_nodeid != res->res_nodeid)
  72                         seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
  73                                    lkb->lkb_remid);
  74                 else
  75                         seq_printf(s, " Master:     %08x", lkb->lkb_remid);
  76         }
  77
  78         if (lkb->lkb_wait_type)
  79                 seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
  80
  81         seq_printf(s, "\n");
  82 }
  83
  84 static int print_resource(struct dlm_rsb *res, struct seq_file *s)
  85 {
  86         struct dlm_lkb *lkb;
  87         int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
  88
  89         seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
  90         for (i = 0; i < res->res_length; i++) {
  91                 if (isprint(res->res_name[i]))
  92                         seq_printf(s, "%c", res->res_name[i]);
  93                 else
  94                         seq_printf(s, "%c", '.');
  95         }
  96         if (res->res_nodeid > 0)
  97                 seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
  98                            res->res_nodeid);
  99         else if (res->res_nodeid == 0)
 100                 seq_printf(s, "\"  \nMaster Copy\n");
 101         else if (res->res_nodeid == -1)
 102                 seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
 103                            res->res_first_lkid);
 104         else
 105                 seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
 106
 107         /* Print the LVB: */
 108         if (res->res_lvbptr) {
 109                 seq_printf(s, "LVB: ");
 110                 for (i = 0; i < lvblen; i++) {
 111                         if (i == lvblen / 2)
 112                                 seq_printf(s, "\n     ");
 113                         seq_printf(s, "%02x ",
 114                                    (unsigned char) res->res_lvbptr[i]);
 115                 }
 116                 if (rsb_flag(res, RSB_VALNOTVALID))
 117                         seq_printf(s, " (INVALID)");
 118                 seq_printf(s, "\n");
 119         }
 120
 121         root_list = !list_empty(&res->res_root_list);
 122         recover_list = !list_empty(&res->res_recover_list);
 123
 124         if (root_list || recover_list) {
 125                 seq_printf(s, "Recovery: root %d recover %d flags %lx "
 126                            "count %d\n", root_list, recover_list,
 127                            res->res_flags, res->res_recover_locks_count);
 128         }
 129
 130         /* Print the locks attached to this resource */
 131         seq_printf(s, "Granted Queue\n");
 132         list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
 133                 print_lock(s, lkb, res);
 134
 135         seq_printf(s, "Conversion Queue\n");
 136         list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
 137                 print_lock(s, lkb, res);
 138
 139         seq_printf(s, "Waiting Queue\n");
 140         list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
 141                 print_lock(s, lkb, res);
 142
 143         if (list_empty(&res->res_lookup))
 144                 goto out;
 145
 146         seq_printf(s, "Lookup Queue\n");
 147         list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
 148                 seq_printf(s, "%08x %s", lkb->lkb_id,
 149                            print_lockmode(lkb->lkb_rqmode));
 150                 if (lkb->lkb_wait_type)
 151                         seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
 152                 seq_printf(s, "\n");
 153         }
 154  out:
 155         return 0;
 156 }
 157
 158 static int rsb_iter_next(struct rsb_iter *ri)
 159 {
 160         struct dlm_ls *ls = ri->ls;
 161         int i;
 162
 163         if (!ri->next) {
 164  top:
 165                 /* Find the next non-empty hash bucket */
 166                 for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
 167                         read_lock(&ls->ls_rsbtbl[i].lock);
 168                         if (!list_empty(&ls->ls_rsbtbl[i].list)) {
 169                                 ri->next = ls->ls_rsbtbl[i].list.next;
 170                                 ri->rsb = list_entry(ri->next, struct dlm_rsb,
 171                                                         res_hashchain);
 172                                 dlm_hold_rsb(ri->rsb);
 173                                 read_unlock(&ls->ls_rsbtbl[i].lock);
 174                                 break;
 175                         }
 176                         read_unlock(&ls->ls_rsbtbl[i].lock);
 177                 }
 178                 ri->entry = i;
 179
 180                 if (ri->entry >= ls->ls_rsbtbl_size)
 181                         return 1;
 182         } else {
 183                 struct dlm_rsb *old = ri->rsb;
 184                 i = ri->entry;
 185                 read_lock(&ls->ls_rsbtbl[i].lock);
 186                 ri->next = ri->next->next;
 187                 if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
 188                         /* End of list - move to next bucket */
 189                         ri->next = NULL;
 190                         ri->entry++;
 191                         read_unlock(&ls->ls_rsbtbl[i].lock);
 192                         dlm_put_rsb(old);
 193                         goto top;
 194                 }
 195                 ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
 196                 read_unlock(&ls->ls_rsbtbl[i].lock);
 197                 dlm_put_rsb(old);
 198         }
 199
 200         return 0;
 201 }
 202
 203 static void rsb_iter_free(struct rsb_iter *ri)
 204 {
 205         kfree(ri);
 206 }
 207
 208 static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
 209 {
 210         struct rsb_iter *ri;
 211
 212         ri = kmalloc(sizeof *ri, GFP_KERNEL);
 213         if (!ri)
 214                 return NULL;
 215
 216         ri->ls = ls;
 217         ri->entry = 0;
 218         ri->next = NULL;
 219
 220         if (rsb_iter_next(ri)) {
 221                 rsb_iter_free(ri);
 222                 return NULL;
 223         }
 224
 225         return ri;
 226 }
 227
 228 static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
 229 {
 230         struct rsb_iter *ri;
 231         loff_t n = *pos;
 232
 233         ri = rsb_iter_init(file->private);
 234         if (!ri)
 235                 return NULL;
 236
 237         while (n--) {
 238                 if (rsb_iter_next(ri)) {
 239                         rsb_iter_free(ri);
 240                         return NULL;
 241                 }
 242         }
 243
 244         return ri;
 245 }
 246
 247 static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
 248 {
 249         struct rsb_iter *ri = iter_ptr;
 250
 251         (*pos)++;
 252
 253         if (rsb_iter_next(ri)) {
 254                 rsb_iter_free(ri);
 255                 return NULL;
 256         }
 257
 258         return ri;
 259 }
 260
 261 static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
 262 {
 263         /* nothing for now */
 264 }
 265
 266 static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
 267 {
 268         struct rsb_iter *ri = iter_ptr;
 269
 270         print_resource(ri->rsb, file);
 271
 272         return 0;
 273 }
 274
 275 static struct seq_operations rsb_seq_ops = {
 276         .start = rsb_seq_start,
 277         .next  = rsb_seq_next,
 278         .stop  = rsb_seq_stop,
 279         .show  = rsb_seq_show,
 280 };
 281
 282 static int rsb_open(struct inode *inode, struct file *file)
 283 {
 284         struct seq_file *seq;
 285         int ret;
 286
 287         ret = seq_open(file, &rsb_seq_ops);
 288         if (ret)
 289                 return ret;
 290
 291         seq = file->private_data;
 292         seq->private = inode->i_private;
 293
 294         return 0;
 295 }
 296
 297 static const struct file_operations rsb_fops = {
 298         .owner   = THIS_MODULE,
 299         .open    = rsb_open,
 300         .read    = seq_read,
 301         .llseek  = seq_lseek,
 302         .release = seq_release
 303 };
 304
 305 /*
 306  * dump lkb's on the ls_waiters list
 307  */
 308
 309 static int waiters_open(struct inode *inode, struct file *file)
 310 {
 311         file->private_data = inode->i_private;
 312         return 0;
 313 }
 314
 315 static ssize_t waiters_read(struct file *file, char __user *userbuf,
 316                             size_t count, loff_t *ppos)
 317 {
 318         struct dlm_ls *ls = file->private_data;
 319         struct dlm_lkb *lkb;
 320         size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
 321
 322         mutex_lock(&debug_buf_lock);
 323         mutex_lock(&ls->ls_waiters_mutex);
 324         memset(debug_buf, 0, sizeof(debug_buf));
 325
 326         list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
 327                 ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
 328                                lkb->lkb_id, lkb->lkb_wait_type,
 329                                lkb->lkb_nodeid, lkb->lkb_resource->res_name);
 330                 if (ret >= len - pos)
 331                         break;
 332                 pos += ret;
 333         }
 334         mutex_unlock(&ls->ls_waiters_mutex);
 335
 336         rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
 337         mutex_unlock(&debug_buf_lock);
 338         return rv;
 339 }
 340
 341 static const struct file_operations waiters_fops = {
 342         .owner   = THIS_MODULE,
 343         .open    = waiters_open,
 344         .read    = waiters_read
 345 };
 346
 347 int dlm_create_debug_file(struct dlm_ls *ls)
 348 {
 349         char name[DLM_LOCKSPACE_LEN+8];
 350
 351         ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
 352                                                       S_IFREG | S_IRUGO,
 353                                                       dlm_root,
 354                                                       ls,
 355                                                       &rsb_fops);
 356         if (!ls->ls_debug_rsb_dentry)
 357                 return -ENOMEM;
 358
 359         memset(name, 0, sizeof(name));
 360         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
 361
 362         ls->ls_debug_waiters_dentry = debugfs_create_file(name,
 363                                                           S_IFREG | S_IRUGO,
 364                                                           dlm_root,
 365                                                           ls,
 366                                                           &waiters_fops);
 367         if (!ls->ls_debug_waiters_dentry) {
 368                 debugfs_remove(ls->ls_debug_rsb_dentry);
 369                 return -ENOMEM;
 370         }
 371
 372         return 0;
 373 }
 374
 375 void dlm_delete_debug_file(struct dlm_ls *ls)
 376 {
 377         if (ls->ls_debug_rsb_dentry)
 378                 debugfs_remove(ls->ls_debug_rsb_dentry);
 379         if (ls->ls_debug_waiters_dentry)
 380                 debugfs_remove(ls->ls_debug_waiters_dentry);
 381 }
 382
 383 int dlm_register_debugfs(void)
 384 {
 385         mutex_init(&debug_buf_lock);
 386         dlm_root = debugfs_create_dir("dlm", NULL);
 387         return dlm_root ? 0 : -ENOMEM;
 388 }
 389
 390 void dlm_unregister_debugfs(void)
 391 {
 392         debugfs_remove(dlm_root);
 393 }
 394