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
  22 static struct dentry *dlm_root;
  23
  24 struct rsb_iter {
  25         int entry;
  26         struct dlm_ls *ls;
  27         struct list_head *next;
  28         struct dlm_rsb *rsb;
  29 };
  30
  31 static char *print_lockmode(int mode)
  32 {
  33         switch (mode) {
  34         case DLM_LOCK_IV:
  35                 return "--";
  36         case DLM_LOCK_NL:
  37                 return "NL";
  38         case DLM_LOCK_CR:
  39                 return "CR";
  40         case DLM_LOCK_CW:
  41                 return "CW";
  42         case DLM_LOCK_PR:
  43                 return "PR";
  44         case DLM_LOCK_PW:
  45                 return "PW";
  46         case DLM_LOCK_EX:
  47                 return "EX";
  48         default:
  49                 return "??";
  50         }
  51 }
  52
  53 static void print_lock(struct seq_file *s, struct dlm_lkb *lkb,
  54                        struct dlm_rsb *res)
  55 {
  56         seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
  57
  58         if (lkb->lkb_status == DLM_LKSTS_CONVERT
  59             || lkb->lkb_status == DLM_LKSTS_WAITING)
  60                 seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
  61
  62         if (lkb->lkb_nodeid) {
  63                 if (lkb->lkb_nodeid != res->res_nodeid)
  64                         seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
  65                                    lkb->lkb_remid);
  66                 else
  67                         seq_printf(s, " Master:     %08x", lkb->lkb_remid);
  68         }
  69
  70         if (lkb->lkb_wait_type)
  71                 seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
  72
  73         seq_printf(s, "\n");
  74 }
  75
  76 static int print_resource(struct dlm_rsb *res, struct seq_file *s)
  77 {
  78         struct dlm_lkb *lkb;
  79         int i, lvblen = res->res_ls->ls_lvblen;
  80
  81         seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
  82         for (i = 0; i < res->res_length; i++) {
  83                 if (isprint(res->res_name[i]))
  84                         seq_printf(s, "%c", res->res_name[i]);
  85                 else
  86                         seq_printf(s, "%c", '.');
  87         }
  88         if (res->res_nodeid > 0)
  89                 seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
  90                            res->res_nodeid);
  91         else if (res->res_nodeid == 0)
  92                 seq_printf(s, "\"  \nMaster Copy\n");
  93         else if (res->res_nodeid == -1)
  94                 seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
  95                            res->res_first_lkid);
  96         else
  97                 seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
  98
  99         /* Print the LVB: */
 100         if (res->res_lvbptr) {
 101                 seq_printf(s, "LVB: ");
 102                 for (i = 0; i < lvblen; i++) {
 103                         if (i == lvblen / 2)
 104                                 seq_printf(s, "\n     ");
 105                         seq_printf(s, "%02x ",
 106                                    (unsigned char) res->res_lvbptr[i]);
 107                 }
 108                 if (rsb_flag(res, RSB_VALNOTVALID))
 109                         seq_printf(s, " (INVALID)");
 110                 seq_printf(s, "\n");
 111         }
 112
 113         /* Print the locks attached to this resource */
 114         seq_printf(s, "Granted Queue\n");
 115         list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
 116                 print_lock(s, lkb, res);
 117
 118         seq_printf(s, "Conversion Queue\n");
 119         list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
 120                 print_lock(s, lkb, res);
 121
 122         seq_printf(s, "Waiting Queue\n");
 123         list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
 124                 print_lock(s, lkb, res);
 125
 126         return 0;
 127 }
 128
 129 static int rsb_iter_next(struct rsb_iter *ri)
 130 {
 131         struct dlm_ls *ls = ri->ls;
 132         int i;
 133
 134         if (!ri->next) {
 135  top:
 136                 /* Find the next non-empty hash bucket */
 137                 for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
 138                         read_lock(&ls->ls_rsbtbl[i].lock);
 139                         if (!list_empty(&ls->ls_rsbtbl[i].list)) {
 140                                 ri->next = ls->ls_rsbtbl[i].list.next;
 141                                 read_unlock(&ls->ls_rsbtbl[i].lock);
 142                                 break;
 143                         }
 144                         read_unlock(&ls->ls_rsbtbl[i].lock);
 145                 }
 146                 ri->entry = i;
 147
 148                 if (ri->entry >= ls->ls_rsbtbl_size)
 149                         return 1;
 150         } else {
 151                 i = ri->entry;
 152                 read_lock(&ls->ls_rsbtbl[i].lock);
 153                 ri->next = ri->next->next;
 154                 if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
 155                         /* End of list - move to next bucket */
 156                         ri->next = NULL;
 157                         ri->entry++;
 158                         read_unlock(&ls->ls_rsbtbl[i].lock);
 159                         goto top;
 160                 }
 161                 read_unlock(&ls->ls_rsbtbl[i].lock);
 162         }
 163         ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
 164
 165         return 0;
 166 }
 167
 168 static void rsb_iter_free(struct rsb_iter *ri)
 169 {
 170         kfree(ri);
 171 }
 172
 173 static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
 174 {
 175         struct rsb_iter *ri;
 176
 177         ri = kmalloc(sizeof *ri, GFP_KERNEL);
 178         if (!ri)
 179                 return NULL;
 180
 181         ri->ls = ls;
 182         ri->entry = 0;
 183         ri->next = NULL;
 184
 185         if (rsb_iter_next(ri)) {
 186                 rsb_iter_free(ri);
 187                 return NULL;
 188         }
 189
 190         return ri;
 191 }
 192
 193 static void *seq_start(struct seq_file *file, loff_t *pos)
 194 {
 195         struct rsb_iter *ri;
 196         loff_t n = *pos;
 197
 198         ri = rsb_iter_init(file->private);
 199         if (!ri)
 200                 return NULL;
 201
 202         while (n--) {
 203                 if (rsb_iter_next(ri)) {
 204                         rsb_iter_free(ri);
 205                         return NULL;
 206                 }
 207         }
 208
 209         return ri;
 210 }
 211
 212 static void *seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
 213 {
 214         struct rsb_iter *ri = iter_ptr;
 215
 216         (*pos)++;
 217
 218         if (rsb_iter_next(ri)) {
 219                 rsb_iter_free(ri);
 220                 return NULL;
 221         }
 222
 223         return ri;
 224 }
 225
 226 static void seq_stop(struct seq_file *file, void *iter_ptr)
 227 {
 228         /* nothing for now */
 229 }
 230
 231 static int seq_show(struct seq_file *file, void *iter_ptr)
 232 {
 233         struct rsb_iter *ri = iter_ptr;
 234
 235         print_resource(ri->rsb, file);
 236
 237         return 0;
 238 }
 239
 240 static struct seq_operations dlm_seq_ops = {
 241         .start = seq_start,
 242         .next  = seq_next,
 243         .stop  = seq_stop,
 244         .show  = seq_show,
 245 };
 246
 247 static int do_open(struct inode *inode, struct file *file)
 248 {
 249         struct seq_file *seq;
 250         int ret;
 251
 252         ret = seq_open(file, &dlm_seq_ops);
 253         if (ret)
 254                 return ret;
 255
 256         seq = file->private_data;
 257         seq->private = inode->u.generic_ip;
 258
 259         return 0;
 260 }
 261
 262 static struct file_operations dlm_fops = {
 263         .owner   = THIS_MODULE,
 264         .open    = do_open,
 265         .read    = seq_read,
 266         .llseek  = seq_lseek,
 267         .release = seq_release
 268 };
 269
 270 int dlm_create_debug_file(struct dlm_ls *ls)
 271 {
 272         ls->ls_debug_dentry = debugfs_create_file(ls->ls_name,
 273                                                   S_IFREG | S_IRUGO,
 274                                                   dlm_root,
 275                                                   ls,
 276                                                   &dlm_fops);
 277         return ls->ls_debug_dentry ? 0 : -ENOMEM;
 278 }
 279
 280 void dlm_delete_debug_file(struct dlm_ls *ls)
 281 {
 282         if (ls->ls_debug_dentry)
 283                 debugfs_remove(ls->ls_debug_dentry);
 284 }
 285
 286 int dlm_register_debugfs(void)
 287 {
 288         dlm_root = debugfs_create_dir("dlm", NULL);
 289         return dlm_root ? 0 : -ENOMEM;
 290 }
 291
 292 void dlm_unregister_debugfs(void)
 293 {
 294         debugfs_remove(dlm_root);
 295 }
 296