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
  21 #define DLM_DEBUG_BUF_LEN 4096
  22 static char debug_buf[DLM_DEBUG_BUF_LEN];
  23 static struct mutex debug_buf_lock;
  24
  25 static struct dentry *dlm_root;
  26
  27 struct rsb_iter {
  28         int entry;
  29         struct dlm_ls *ls;
  30         struct list_head *next;
  31         struct dlm_rsb *rsb;
  32 };
  33
  34 /*
  35  * dump all rsb's in the lockspace hash table
  36  */
  37
  38 static char *print_lockmode(int mode)
  39 {
  40         switch (mode) {
  41         case DLM_LOCK_IV:
  42                 return "--";
  43         case DLM_LOCK_NL:
  44                 return "NL";
  45         case DLM_LOCK_CR:
  46                 return "CR";
  47         case DLM_LOCK_CW:
  48                 return "CW";
  49         case DLM_LOCK_PR:
  50                 return "PR";
  51         case DLM_LOCK_PW:
  52                 return "PW";
  53         case DLM_LOCK_EX:
  54                 return "EX";
  55         default:
  56                 return "??";
  57         }
  58 }
  59
  60 static void print_lock(struct seq_file *s, struct dlm_lkb *lkb,
  61                        struct dlm_rsb *res)
  62 {
  63         seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
  64
  65         if (lkb->lkb_status == DLM_LKSTS_CONVERT
  66             || lkb->lkb_status == DLM_LKSTS_WAITING)
  67                 seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
  68
  69         if (lkb->lkb_nodeid) {
  70                 if (lkb->lkb_nodeid != res->res_nodeid)
  71                         seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
  72                                    lkb->lkb_remid);
  73                 else
  74                         seq_printf(s, " Master:     %08x", lkb->lkb_remid);
  75         }
  76
  77         if (lkb->lkb_wait_type)
  78                 seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
  79
  80         seq_printf(s, "\n");
  81 }
  82
  83 static int print_resource(struct dlm_rsb *res, struct seq_file *s)
  84 {
  85         struct dlm_lkb *lkb;
  86         int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
  87
  88         seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
  89         for (i = 0; i < res->res_length; i++) {
  90                 if (isprint(res->res_name[i]))
  91                         seq_printf(s, "%c", res->res_name[i]);
  92                 else
  93                         seq_printf(s, "%c", '.');
  94         }
  95         if (res->res_nodeid > 0)
  96                 seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
  97                            res->res_nodeid);
  98         else if (res->res_nodeid == 0)
  99                 seq_printf(s, "\"  \nMaster Copy\n");
 100         else if (res->res_nodeid == -1)
 101                 seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
 102                            res->res_first_lkid);
 103         else
 104                 seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
 105
 106         /* Print the LVB: */
 107         if (res->res_lvbptr) {
 108                 seq_printf(s, "LVB: ");
 109                 for (i = 0; i < lvblen; i++) {
 110                         if (i == lvblen / 2)
 111                                 seq_printf(s, "\n     ");
 112                         seq_printf(s, "%02x ",
 113                                    (unsigned char) res->res_lvbptr[i]);
 114                 }
 115                 if (rsb_flag(res, RSB_VALNOTVALID))
 116                         seq_printf(s, " (INVALID)");
 117                 seq_printf(s, "\n");
 118         }
 119
 120         root_list = !list_empty(&res->res_root_list);
 121         recover_list = !list_empty(&res->res_recover_list);
 122
 123         if (root_list || recover_list) {
 124                 seq_printf(s, "Recovery: root %d recover %d flags %lx "
 125                            "count %d\n", root_list, recover_list,
 126                            res->res_flags, res->res_recover_locks_count);
 127         }
 128
 129         /* Print the locks attached to this resource */
 130         seq_printf(s, "Granted Queue\n");
 131         list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
 132                 print_lock(s, lkb, res);
 133
 134         seq_printf(s, "Conversion Queue\n");
 135         list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
 136                 print_lock(s, lkb, res);
 137
 138         seq_printf(s, "Waiting Queue\n");
 139         list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
 140                 print_lock(s, lkb, res);
 141
 142         if (list_empty(&res->res_lookup))
 143                 goto out;
 144
 145         seq_printf(s, "Lookup Queue\n");
 146         list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
 147                 seq_printf(s, "%08x %s", lkb->lkb_id,
 148                            print_lockmode(lkb->lkb_rqmode));
 149                 if (lkb->lkb_wait_type)
 150                         seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
 151                 seq_printf(s, "\n");
 152         }
 153  out:
 154         return 0;
 155 }
 156
 157 static int rsb_iter_next(struct rsb_iter *ri)
 158 {
 159         struct dlm_ls *ls = ri->ls;
 160         int i;
 161
 162         if (!ri->next) {
 163  top:
 164                 /* Find the next non-empty hash bucket */
 165                 for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
 166                         read_lock(&ls->ls_rsbtbl[i].lock);
 167                         if (!list_empty(&ls->ls_rsbtbl[i].list)) {
 168                                 ri->next = ls->ls_rsbtbl[i].list.next;
 169                                 read_unlock(&ls->ls_rsbtbl[i].lock);
 170                                 break;
 171                         }
 172                         read_unlock(&ls->ls_rsbtbl[i].lock);
 173                 }
 174                 ri->entry = i;
 175
 176                 if (ri->entry >= ls->ls_rsbtbl_size)
 177                         return 1;
 178         } else {
 179                 i = ri->entry;
 180                 read_lock(&ls->ls_rsbtbl[i].lock);
 181                 ri->next = ri->next->next;
 182                 if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
 183                         /* End of list - move to next bucket */
 184                         ri->next = NULL;
 185                         ri->entry++;
 186                         read_unlock(&ls->ls_rsbtbl[i].lock);
 187                         goto top;
 188                 }
 189                 read_unlock(&ls->ls_rsbtbl[i].lock);
 190         }
 191         ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
 192
 193         return 0;
 194 }
 195
 196 static void rsb_iter_free(struct rsb_iter *ri)
 197 {
 198         kfree(ri);
 199 }
 200
 201 static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
 202 {
 203         struct rsb_iter *ri;
 204
 205         ri = kmalloc(sizeof *ri, GFP_KERNEL);
 206         if (!ri)
 207                 return NULL;
 208
 209         ri->ls = ls;
 210         ri->entry = 0;
 211         ri->next = NULL;
 212
 213         if (rsb_iter_next(ri)) {
 214                 rsb_iter_free(ri);
 215                 return NULL;
 216         }
 217
 218         return ri;
 219 }
 220
 221 static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
 222 {
 223         struct rsb_iter *ri;
 224         loff_t n = *pos;
 225
 226         ri = rsb_iter_init(file->private);
 227         if (!ri)
 228                 return NULL;
 229
 230         while (n--) {
 231                 if (rsb_iter_next(ri)) {
 232                         rsb_iter_free(ri);
 233                         return NULL;
 234                 }
 235         }
 236
 237         return ri;
 238 }
 239
 240 static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
 241 {
 242         struct rsb_iter *ri = iter_ptr;
 243
 244         (*pos)++;
 245
 246         if (rsb_iter_next(ri)) {
 247                 rsb_iter_free(ri);
 248                 return NULL;
 249         }
 250
 251         return ri;
 252 }
 253
 254 static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
 255 {
 256         /* nothing for now */
 257 }
 258
 259 static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
 260 {
 261         struct rsb_iter *ri = iter_ptr;
 262
 263         print_resource(ri->rsb, file);
 264
 265         return 0;
 266 }
 267
 268 static struct seq_operations rsb_seq_ops = {
 269         .start = rsb_seq_start,
 270         .next  = rsb_seq_next,
 271         .stop  = rsb_seq_stop,
 272         .show  = rsb_seq_show,
 273 };
 274
 275 static int rsb_open(struct inode *inode, struct file *file)
 276 {
 277         struct seq_file *seq;
 278         int ret;
 279
 280         ret = seq_open(file, &rsb_seq_ops);
 281         if (ret)
 282                 return ret;
 283
 284         seq = file->private_data;
 285         seq->private = inode->i_private;
 286
 287         return 0;
 288 }
 289
 290 static const struct file_operations rsb_fops = {
 291         .owner   = THIS_MODULE,
 292         .open    = rsb_open,
 293         .read    = seq_read,
 294         .llseek  = seq_lseek,
 295         .release = seq_release
 296 };
 297
 298 /*
 299  * dump lkb's on the ls_waiters list
 300  */
 301
 302 static int waiters_open(struct inode *inode, struct file *file)
 303 {
 304         file->private_data = inode->i_private;
 305         return 0;
 306 }
 307
 308 static ssize_t waiters_read(struct file *file, char __user *userbuf,
 309                             size_t count, loff_t *ppos)
 310 {
 311         struct dlm_ls *ls = file->private_data;
 312         struct dlm_lkb *lkb;
 313         size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
 314
 315         mutex_lock(&debug_buf_lock);
 316         mutex_lock(&ls->ls_waiters_mutex);
 317         memset(debug_buf, 0, sizeof(debug_buf));
 318
 319         list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
 320                 ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
 321                                lkb->lkb_id, lkb->lkb_wait_type,
 322                                lkb->lkb_nodeid, lkb->lkb_resource->res_name);
 323                 if (ret >= len - pos)
 324                         break;
 325                 pos += ret;
 326         }
 327         mutex_unlock(&ls->ls_waiters_mutex);
 328
 329         rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
 330         mutex_unlock(&debug_buf_lock);
 331         return rv;
 332 }
 333
 334 static const struct file_operations waiters_fops = {
 335         .owner   = THIS_MODULE,
 336         .open    = waiters_open,
 337         .read    = waiters_read
 338 };
 339
 340 int dlm_create_debug_file(struct dlm_ls *ls)
 341 {
 342         char name[DLM_LOCKSPACE_LEN+8];
 343
 344         ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
 345                                                       S_IFREG | S_IRUGO,
 346                                                       dlm_root,
 347                                                       ls,
 348                                                       &rsb_fops);
 349         if (!ls->ls_debug_rsb_dentry)
 350                 return -ENOMEM;
 351
 352         memset(name, 0, sizeof(name));
 353         snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
 354
 355         ls->ls_debug_waiters_dentry = debugfs_create_file(name,
 356                                                           S_IFREG | S_IRUGO,
 357                                                           dlm_root,
 358                                                           ls,
 359                                                           &waiters_fops);
 360         if (!ls->ls_debug_waiters_dentry) {
 361                 debugfs_remove(ls->ls_debug_rsb_dentry);
 362                 return -ENOMEM;
 363         }
 364
 365         return 0;
 366 }
 367
 368 void dlm_delete_debug_file(struct dlm_ls *ls)
 369 {
 370         if (ls->ls_debug_rsb_dentry)
 371                 debugfs_remove(ls->ls_debug_rsb_dentry);
 372         if (ls->ls_debug_waiters_dentry)
 373                 debugfs_remove(ls->ls_debug_waiters_dentry);
 374 }
 375
 376 int dlm_register_debugfs(void)
 377 {
 378         mutex_init(&debug_buf_lock);
 379         dlm_root = debugfs_create_dir("dlm", NULL);
 380         return dlm_root ? 0 : -ENOMEM;
 381 }
 382
 383 void dlm_unregister_debugfs(void)
 384 {
 385         debugfs_remove(dlm_root);
 386 }
 387