Quelle  dlmdebug.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * dlmdebug.c
 *
 * debug functionality for the dlm
 *
 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/sysctl.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/export.h>
#include <linux/string_choices.h>

#include "../cluster/heartbeat.h"
#include "../cluster/nodemanager.h"
#include "../cluster/tcp.h"

#include "dlmapi.h"
#include "dlmcommon.h"
#include "dlmdomain.h"
#include "dlmdebug.h"

#define MLOG_MASK_PREFIX ML_DLM
#include "../cluster/masklog.h"

static int stringify_lockname(const char *lockname, int locklen, char *buf,
         int len);

void dlm_print_one_lock_resource(struct dlm_lock_resource *res)
{
 spin_lock(&res->spinlock);
 __dlm_print_one_lock_resource(res);
 spin_unlock(&res->spinlock);
}

static void dlm_print_lockres_refmap(struct dlm_lock_resource *res)
{
 int bit;
 assert_spin_locked(&res->spinlock);

 printk(" refmap nodes: [ ");
 bit = 0;
 while (1) {
  bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
  if (bit >= O2NM_MAX_NODES)
   break;
  printk("%u ", bit);
  bit++;
 }
 printk("], inflight=%u\n", res->inflight_locks);
}

static void __dlm_print_lock(struct dlm_lock *lock)
{
 spin_lock(&lock->spinlock);

 printk(" type=%d, conv=%d, node=%u, cookie=%u:%llu, "
        "ref=%u, ast=(empty=%c,pend=%c), bast=(empty=%c,pend=%c), "
        "pending=(conv=%c,lock=%c,cancel=%c,unlock=%c)\n",
        lock->ml.type, lock->ml.convert_type, lock->ml.node,
        dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
        dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
        kref_read(&lock->lock_refs),
        (list_empty(&lock->ast_list) ? 'y' : 'n'),
        (lock->ast_pending ? 'y' : 'n'),
        (list_empty(&lock->bast_list) ? 'y' : 'n'),
        (lock->bast_pending ? 'y' : 'n'),
        (lock->convert_pending ? 'y' : 'n'),
        (lock->lock_pending ? 'y' : 'n'),
        (lock->cancel_pending ? 'y' : 'n'),
        (lock->unlock_pending ? 'y' : 'n'));

 spin_unlock(&lock->spinlock);
}

void __dlm_print_one_lock_resource(struct dlm_lock_resource *res)
{
 struct dlm_lock *lock;
 char buf[DLM_LOCKID_NAME_MAX];

 assert_spin_locked(&res->spinlock);

 stringify_lockname(res->lockname.name, res->lockname.len,
      buf, sizeof(buf));
 printk("lockres: %s, owner=%u, state=%u\n",
        buf, res->owner, res->state);
 printk(" last used: %lu, refcnt: %u, on purge list: %s\n",
        res->last_used, kref_read(&res->refs),
        str_no_yes(list_empty(&res->purge)));
 printk(" on dirty list: %s, on reco list: %s, "
        "migrating pending: %s\n",
        str_no_yes(list_empty(&res->dirty)),
        str_no_yes(list_empty(&res->recovering)),
        str_yes_no(res->migration_pending));
 printk(" inflight locks: %d, asts reserved: %d\n",
        res->inflight_locks, atomic_read(&res->asts_reserved));
 dlm_print_lockres_refmap(res);
 printk(" granted queue:\n");
 list_for_each_entry(lock, &res->granted, list) {
  __dlm_print_lock(lock);
 }
 printk(" converting queue:\n");
 list_for_each_entry(lock, &res->converting, list) {
  __dlm_print_lock(lock);
 }
 printk(" blocked queue:\n");
 list_for_each_entry(lock, &res->blocked, list) {
  __dlm_print_lock(lock);
 }
}

void dlm_print_one_lock(struct dlm_lock *lockid)
{
 dlm_print_one_lock_resource(lockid->lockres);
}
EXPORT_SYMBOL_GPL(dlm_print_one_lock);

static const char *dlm_errnames[] = {
 [DLM_NORMAL] =   "DLM_NORMAL",
 [DLM_GRANTED] =   "DLM_GRANTED",
 [DLM_DENIED] =   "DLM_DENIED",
 [DLM_DENIED_NOLOCKS] =  "DLM_DENIED_NOLOCKS",
 [DLM_WORKING] =   "DLM_WORKING",
 [DLM_BLOCKED] =   "DLM_BLOCKED",
 [DLM_BLOCKED_ORPHAN] =  "DLM_BLOCKED_ORPHAN",
 [DLM_DENIED_GRACE_PERIOD] = "DLM_DENIED_GRACE_PERIOD",
 [DLM_SYSERR] =   "DLM_SYSERR",
 [DLM_NOSUPPORT] =  "DLM_NOSUPPORT",
 [DLM_CANCELGRANT] =  "DLM_CANCELGRANT",
 [DLM_IVLOCKID] =  "DLM_IVLOCKID",
 [DLM_SYNC] =   "DLM_SYNC",
 [DLM_BADTYPE] =   "DLM_BADTYPE",
 [DLM_BADRESOURCE] =  "DLM_BADRESOURCE",
 [DLM_MAXHANDLES] =  "DLM_MAXHANDLES",
 [DLM_NOCLINFO] =  "DLM_NOCLINFO",
 [DLM_NOLOCKMGR] =  "DLM_NOLOCKMGR",
 [DLM_NOPURGED] =  "DLM_NOPURGED",
 [DLM_BADARGS] =   "DLM_BADARGS",
 [DLM_VOID] =   "DLM_VOID",
 [DLM_NOTQUEUED] =  "DLM_NOTQUEUED",
 [DLM_IVBUFLEN] =  "DLM_IVBUFLEN",
 [DLM_CVTUNGRANT] =  "DLM_CVTUNGRANT",
 [DLM_BADPARAM] =  "DLM_BADPARAM",
 [DLM_VALNOTVALID] =  "DLM_VALNOTVALID",
 [DLM_REJECTED] =  "DLM_REJECTED",
 [DLM_ABORT] =   "DLM_ABORT",
 [DLM_CANCEL] =   "DLM_CANCEL",
 [DLM_IVRESHANDLE] =  "DLM_IVRESHANDLE",
 [DLM_DEADLOCK] =  "DLM_DEADLOCK",
 [DLM_DENIED_NOASTS] =  "DLM_DENIED_NOASTS",
 [DLM_FORWARD] =   "DLM_FORWARD",
 [DLM_TIMEOUT] =   "DLM_TIMEOUT",
 [DLM_IVGROUPID] =  "DLM_IVGROUPID",
 [DLM_VERS_CONFLICT] =  "DLM_VERS_CONFLICT",
 [DLM_BAD_DEVICE_PATH] =  "DLM_BAD_DEVICE_PATH",
 [DLM_NO_DEVICE_PERMISSION] = "DLM_NO_DEVICE_PERMISSION",
 [DLM_NO_CONTROL_DEVICE ] = "DLM_NO_CONTROL_DEVICE ",
 [DLM_RECOVERING] =  "DLM_RECOVERING",
 [DLM_MIGRATING] =  "DLM_MIGRATING",
 [DLM_MAXSTATS] =  "DLM_MAXSTATS",
};

const char *dlm_errname(enum dlm_status err)
{
 if (err >= DLM_MAXSTATS || err < 0)
  return dlm_errnames[DLM_MAXSTATS];
 return dlm_errnames[err];
}
EXPORT_SYMBOL_GPL(dlm_errname);

/* NOTE: This function converts a lockname into a string. It uses knowledge
 * of the format of the lockname that should be outside the purview of the dlm.
 * We are adding only to make dlm debugging slightly easier.
 *
 * For more on lockname formats, please refer to dlmglue.c and ocfs2_lockid.h.
 */
static int stringify_lockname(const char *lockname, int locklen, char *buf,
         int len)
{
 int out = 0;
 __be64 inode_blkno_be;

#define OCFS2_DENTRY_LOCK_INO_START 18
 if (*lockname == 'N') {
  memcpy((__be64 *)&inode_blkno_be,
         (char *)&lockname[OCFS2_DENTRY_LOCK_INO_START],
         sizeof(__be64));
  out += scnprintf(buf + out, len - out, "%.*s%08x",
    OCFS2_DENTRY_LOCK_INO_START - 1, lockname,
    (unsigned int)be64_to_cpu(inode_blkno_be));
 } else
  out += scnprintf(buf + out, len - out, "%.*s",
    locklen, lockname);
 return out;
}

static int stringify_nodemap(unsigned long *nodemap, int maxnodes,
        char *buf, int len)
{
 int out = 0;
 int i = -1;

 while ((i = find_next_bit(nodemap, maxnodes, i + 1)) < maxnodes)
  out += scnprintf(buf + out, len - out, "%d ", i);

 return out;
}

static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
{
 int out = 0;
 char *mle_type;

 if (mle->type == DLM_MLE_BLOCK)
  mle_type = "BLK";
 else if (mle->type == DLM_MLE_MASTER)
  mle_type = "MAS";
 else
  mle_type = "MIG";

 out += stringify_lockname(mle->mname, mle->mnamelen, buf + out, len - out);
 out += scnprintf(buf + out, len - out,
   "\t%3s\tmas=%3u\tnew=%3u\tevt=%1d\tuse=%1d\tref=%3d\n",
   mle_type, mle->master, mle->new_master,
   !list_empty(&mle->hb_events),
   !!mle->inuse,
   kref_read(&mle->mle_refs));

 out += scnprintf(buf + out, len - out, "Maybe=");
 out += stringify_nodemap(mle->maybe_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 out += scnprintf(buf + out, len - out, "Vote=");
 out += stringify_nodemap(mle->vote_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 out += scnprintf(buf + out, len - out, "Response=");
 out += stringify_nodemap(mle->response_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 out += scnprintf(buf + out, len - out, "Node=");
 out += stringify_nodemap(mle->node_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 out += scnprintf(buf + out, len - out, "\n");

 return out;
}

void dlm_print_one_mle(struct dlm_master_list_entry *mle)
{
 char *buf;

 buf = (char *) get_zeroed_page(GFP_ATOMIC);
 if (buf) {
  dump_mle(mle, buf, PAGE_SIZE - 1);
  free_page((unsigned long)buf);
 }
}

#ifdef CONFIG_DEBUG_FS

static struct dentry *dlm_debugfs_root;

#define DLM_DEBUGFS_DIR    "o2dlm"
#define DLM_DEBUGFS_DLM_STATE   "dlm_state"
#define DLM_DEBUGFS_LOCKING_STATE  "locking_state"
#define DLM_DEBUGFS_MLE_STATE   "mle_state"
#define DLM_DEBUGFS_PURGE_LIST   "purge_list"

/* begin - utils funcs */
static int debug_release(struct inode *inode, struct file *file)
{
 free_page((unsigned long)file->private_data);
 return 0;
}

static ssize_t debug_read(struct file *file, char __user *buf,
     size_t nbytes, loff_t *ppos)
{
 return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
           i_size_read(file->f_mapping->host));
}
/* end - util funcs */

/* begin - purge list funcs */
static int debug_purgelist_print(struct dlm_ctxt *dlm, char *buf, int len)
{
 struct dlm_lock_resource *res;
 int out = 0;
 unsigned long total = 0;

 out += scnprintf(buf + out, len - out,
   "Dumping Purgelist for Domain: %s\n", dlm->name);

 spin_lock(&dlm->spinlock);
 list_for_each_entry(res, &dlm->purge_list, purge) {
  ++total;
  if (len - out < 100)
   continue;
  spin_lock(&res->spinlock);
  out += stringify_lockname(res->lockname.name,
       res->lockname.len,
       buf + out, len - out);
  out += scnprintf(buf + out, len - out, "\t%ld\n",
    (jiffies - res->last_used)/HZ);
  spin_unlock(&res->spinlock);
 }
 spin_unlock(&dlm->spinlock);

 out += scnprintf(buf + out, len - out, "Total on list: %lu\n", total);

 return out;
}

static int debug_purgelist_open(struct inode *inode, struct file *file)
{
 struct dlm_ctxt *dlm = inode->i_private;
 char *buf = NULL;

 buf = (char *) get_zeroed_page(GFP_NOFS);
 if (!buf)
  goto bail;

 i_size_write(inode, debug_purgelist_print(dlm, buf, PAGE_SIZE - 1));

 file->private_data = buf;

 return 0;
bail:
 return -ENOMEM;
}

static const struct file_operations debug_purgelist_fops = {
 .open =  debug_purgelist_open,
 .release = debug_release,
 .read =  debug_read,
 .llseek = generic_file_llseek,
};
/* end - purge list funcs */

/* begin - debug mle funcs */
static int debug_mle_print(struct dlm_ctxt *dlm, char *buf, int len)
{
 struct dlm_master_list_entry *mle;
 struct hlist_head *bucket;
 int i, out = 0;
 unsigned long total = 0, longest = 0, bucket_count = 0;

 out += scnprintf(buf + out, len - out,
   "Dumping MLEs for Domain: %s\n", dlm->name);

 spin_lock(&dlm->master_lock);
 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
  bucket = dlm_master_hash(dlm, i);
  hlist_for_each_entry(mle, bucket, master_hash_node) {
   ++total;
   ++bucket_count;
   if (len - out < 200)
    continue;
   out += dump_mle(mle, buf + out, len - out);
  }
  longest = max(longest, bucket_count);
  bucket_count = 0;
 }
 spin_unlock(&dlm->master_lock);

 out += scnprintf(buf + out, len - out,
   "Total: %lu, Longest: %lu\n", total, longest);
 return out;
}

static int debug_mle_open(struct inode *inode, struct file *file)
{
 struct dlm_ctxt *dlm = inode->i_private;
 char *buf = NULL;

 buf = (char *) get_zeroed_page(GFP_NOFS);
 if (!buf)
  goto bail;

 i_size_write(inode, debug_mle_print(dlm, buf, PAGE_SIZE - 1));

 file->private_data = buf;

 return 0;
bail:
 return -ENOMEM;
}

static const struct file_operations debug_mle_fops = {
 .open =  debug_mle_open,
 .release = debug_release,
 .read =  debug_read,
 .llseek = generic_file_llseek,
};

/* end - debug mle funcs */

/* begin - debug lockres funcs */
static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
{
 int out;

#define DEBUG_LOCK_VERSION 1
 spin_lock(&lock->spinlock);
 out = scnprintf(buf, len, "LOCK:%d,%d,%d,%d,%d,%d:%lld,%d,%d,%d,%d,%d,"
         "%d,%d,%d,%d\n",
         DEBUG_LOCK_VERSION,
         list_type, lock->ml.type, lock->ml.convert_type,
         lock->ml.node,
         dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
         dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
         !list_empty(&lock->ast_list),
         !list_empty(&lock->bast_list),
         lock->ast_pending, lock->bast_pending,
         lock->convert_pending, lock->lock_pending,
         lock->cancel_pending, lock->unlock_pending,
         kref_read(&lock->lock_refs));
 spin_unlock(&lock->spinlock);

 return out;
}

static int dump_lockres(struct dlm_lock_resource *res, char *buf, int len)
{
 struct dlm_lock *lock;
 int i;
 int out = 0;

 out += scnprintf(buf + out, len - out, "NAME:");
 out += stringify_lockname(res->lockname.name, res->lockname.len,
      buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

#define DEBUG_LRES_VERSION 1
 out += scnprintf(buf + out, len - out,
   "LRES:%d,%d,%d,%ld,%d,%d,%d,%d,%d,%d,%d\n",
   DEBUG_LRES_VERSION,
   res->owner, res->state, res->last_used,
   !list_empty(&res->purge),
   !list_empty(&res->dirty),
   !list_empty(&res->recovering),
   res->inflight_locks, res->migration_pending,
   atomic_read(&res->asts_reserved),
   kref_read(&res->refs));

 /* refmap */
 out += scnprintf(buf + out, len - out, "RMAP:");
 out += stringify_nodemap(res->refmap, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 /* lvb */
 out += scnprintf(buf + out, len - out, "LVBX:");
 for (i = 0; i < DLM_LVB_LEN; i++)
  out += scnprintf(buf + out, len - out,
     "%02x", (unsigned char)res->lvb[i]);
 out += scnprintf(buf + out, len - out, "\n");

 /* granted */
 list_for_each_entry(lock, &res->granted, list)
  out += dump_lock(lock, 0, buf + out, len - out);

 /* converting */
 list_for_each_entry(lock, &res->converting, list)
  out += dump_lock(lock, 1, buf + out, len - out);

 /* blocked */
 list_for_each_entry(lock, &res->blocked, list)
  out += dump_lock(lock, 2, buf + out, len - out);

 out += scnprintf(buf + out, len - out, "\n");

 return out;
}

static void *lockres_seq_start(struct seq_file *m, loff_t *pos)
{
 struct debug_lockres *dl = m->private;
 struct dlm_ctxt *dlm = dl->dl_ctxt;
 struct dlm_lock_resource *oldres = dl->dl_res;
 struct dlm_lock_resource *res = NULL, *iter;
 struct list_head *track_list;

 spin_lock(&dlm->track_lock);
 if (oldres)
  track_list = &oldres->tracking;
 else {
  track_list = &dlm->tracking_list;
  if (list_empty(track_list)) {
   dl = NULL;
   spin_unlock(&dlm->track_lock);
   goto bail;
  }
 }

 list_for_each_entry(iter, track_list, tracking) {
  if (&iter->tracking != &dlm->tracking_list) {
   dlm_lockres_get(iter);
   res = iter;
  }
  break;
 }
 spin_unlock(&dlm->track_lock);

 if (oldres)
  dlm_lockres_put(oldres);

 dl->dl_res = res;

 if (res) {
  spin_lock(&res->spinlock);
  dump_lockres(res, dl->dl_buf, dl->dl_len - 1);
  spin_unlock(&res->spinlock);
 } else
  dl = NULL;

bail:
 /* passed to seq_show */
 return dl;
}

static void lockres_seq_stop(struct seq_file *m, void *v)
{
}

static void *lockres_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
 return NULL;
}

static int lockres_seq_show(struct seq_file *s, void *v)
{
 struct debug_lockres *dl = (struct debug_lockres *)v;

 seq_printf(s, "%s", dl->dl_buf);

 return 0;
}

static const struct seq_operations debug_lockres_ops = {
 .start = lockres_seq_start,
 .stop =  lockres_seq_stop,
 .next =  lockres_seq_next,
 .show =  lockres_seq_show,
};

static int debug_lockres_open(struct inode *inode, struct file *file)
{
 struct dlm_ctxt *dlm = inode->i_private;
 struct debug_lockres *dl;
 void *buf;

 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 if (!buf)
  goto bail;

 dl = __seq_open_private(file, &debug_lockres_ops, sizeof(*dl));
 if (!dl)
  goto bailfree;

 dl->dl_len = PAGE_SIZE;
 dl->dl_buf = buf;

 dlm_grab(dlm);
 dl->dl_ctxt = dlm;

 return 0;

bailfree:
 kfree(buf);
bail:
 mlog_errno(-ENOMEM);
 return -ENOMEM;
}

static int debug_lockres_release(struct inode *inode, struct file *file)
{
 struct seq_file *seq = file->private_data;
 struct debug_lockres *dl = (struct debug_lockres *)seq->private;

 if (dl->dl_res)
  dlm_lockres_put(dl->dl_res);
 dlm_put(dl->dl_ctxt);
 kfree(dl->dl_buf);
 return seq_release_private(inode, file);
}

static const struct file_operations debug_lockres_fops = {
 .open =  debug_lockres_open,
 .release = debug_lockres_release,
 .read =  seq_read,
 .llseek = seq_lseek,
};
/* end - debug lockres funcs */

/* begin - debug state funcs */
static int debug_state_print(struct dlm_ctxt *dlm, char *buf, int len)
{
 int out = 0;
 struct dlm_reco_node_data *node;
 char *state;
 int cur_mles = 0, tot_mles = 0;
 int i;

 spin_lock(&dlm->spinlock);

 switch (dlm->dlm_state) {
 case DLM_CTXT_NEW:
  state = "NEW"; break;
 case DLM_CTXT_JOINED:
  state = "JOINED"; break;
 case DLM_CTXT_IN_SHUTDOWN:
  state = "SHUTDOWN"; break;
 case DLM_CTXT_LEAVING:
  state = "LEAVING"; break;
 default:
  state = "UNKNOWN"; break;
 }

 /* Domain: xxxxxxxxxx  Key: 0xdfbac769 */
 out += scnprintf(buf + out, len - out,
   "Domain: %s Key: 0x%08x Protocol: %d.%d\n",
   dlm->name, dlm->key, dlm->dlm_locking_proto.pv_major,
   dlm->dlm_locking_proto.pv_minor);

 /* Thread Pid: xxx  Node: xxx  State: xxxxx */
 out += scnprintf(buf + out, len - out,
   "Thread Pid: %d Node: %d State: %s\n",
   task_pid_nr(dlm->dlm_thread_task), dlm->node_num, state);

 /* Number of Joins: xxx  Joining Node: xxx */
 out += scnprintf(buf + out, len - out,
   "Number of Joins: %d Joining Node: %d\n",
   dlm->num_joins, dlm->joining_node);

 /* Domain Map: xx xx xx */
 out += scnprintf(buf + out, len - out, "Domain Map: ");
 out += stringify_nodemap(dlm->domain_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 /* Exit Domain Map: xx xx xx */
 out += scnprintf(buf + out, len - out, "Exit Domain Map: ");
 out += stringify_nodemap(dlm->exit_domain_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 /* Live Map: xx xx xx */
 out += scnprintf(buf + out, len - out, "Live Map: ");
 out += stringify_nodemap(dlm->live_nodes_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 /* Lock Resources: xxx (xxx) */
 out += scnprintf(buf + out, len - out,
   "Lock Resources: %d (%d)\n",
   atomic_read(&dlm->res_cur_count),
   atomic_read(&dlm->res_tot_count));

 for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
  tot_mles += atomic_read(&dlm->mle_tot_count[i]);

 for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
  cur_mles += atomic_read(&dlm->mle_cur_count[i]);

 /* MLEs: xxx (xxx) */
 out += scnprintf(buf + out, len - out,
   "MLEs: %d (%d)\n", cur_mles, tot_mles);

 /*  Blocking: xxx (xxx) */
 out += scnprintf(buf + out, len - out,
   " Blocking: %d (%d)\n",
   atomic_read(&dlm->mle_cur_count[DLM_MLE_BLOCK]),
   atomic_read(&dlm->mle_tot_count[DLM_MLE_BLOCK]));

 /*  Mastery: xxx (xxx) */
 out += scnprintf(buf + out, len - out,
   " Mastery: %d (%d)\n",
   atomic_read(&dlm->mle_cur_count[DLM_MLE_MASTER]),
   atomic_read(&dlm->mle_tot_count[DLM_MLE_MASTER]));

 /*  Migration: xxx (xxx) */
 out += scnprintf(buf + out, len - out,
   " Migration: %d (%d)\n",
   atomic_read(&dlm->mle_cur_count[DLM_MLE_MIGRATION]),
   atomic_read(&dlm->mle_tot_count[DLM_MLE_MIGRATION]));

 /* Lists: Dirty=Empty  Purge=InUse  PendingASTs=Empty  ... */
 out += scnprintf(buf + out, len - out,
   "Lists: Dirty=%s Purge=%s PendingASTs=%s "
   "PendingBASTs=%s\n",
   (list_empty(&dlm->dirty_list) ? "Empty" : "InUse"),
   (list_empty(&dlm->purge_list) ? "Empty" : "InUse"),
   (list_empty(&dlm->pending_asts) ? "Empty" : "InUse"),
   (list_empty(&dlm->pending_basts) ? "Empty" : "InUse"));

 /* Purge Count: xxx  Refs: xxx */
 out += scnprintf(buf + out, len - out,
   "Purge Count: %d Refs: %d\n", dlm->purge_count,
   kref_read(&dlm->dlm_refs));

 /* Dead Node: xxx */
 out += scnprintf(buf + out, len - out,
   "Dead Node: %d\n", dlm->reco.dead_node);

 /* What about DLM_RECO_STATE_FINALIZE? */
 if (dlm->reco.state == DLM_RECO_STATE_ACTIVE)
  state = "ACTIVE";
 else
  state = "INACTIVE";

 /* Recovery Pid: xxxx  Master: xxx  State: xxxx */
 out += scnprintf(buf + out, len - out,
   "Recovery Pid: %d Master: %d State: %s\n",
   task_pid_nr(dlm->dlm_reco_thread_task),
   dlm->reco.new_master, state);

 /* Recovery Map: xx xx */
 out += scnprintf(buf + out, len - out, "Recovery Map: ");
 out += stringify_nodemap(dlm->recovery_map, O2NM_MAX_NODES,
     buf + out, len - out);
 out += scnprintf(buf + out, len - out, "\n");

 /* Recovery Node State: */
 out += scnprintf(buf + out, len - out, "Recovery Node State:\n");
 list_for_each_entry(node, &dlm->reco.node_data, list) {
  switch (node->state) {
  case DLM_RECO_NODE_DATA_INIT:
   state = "INIT";
   break;
  case DLM_RECO_NODE_DATA_REQUESTING:
   state = "REQUESTING";
   break;
  case DLM_RECO_NODE_DATA_DEAD:
   state = "DEAD";
   break;
  case DLM_RECO_NODE_DATA_RECEIVING:
   state = "RECEIVING";
   break;
  case DLM_RECO_NODE_DATA_REQUESTED:
   state = "REQUESTED";
   break;
  case DLM_RECO_NODE_DATA_DONE:
   state = "DONE";
   break;
  case DLM_RECO_NODE_DATA_FINALIZE_SENT:
   state = "FINALIZE-SENT";
   break;
  default:
   state = "BAD";
   break;
  }
  out += scnprintf(buf + out, len - out, "\t%u - %s\n",
    node->node_num, state);
 }

 spin_unlock(&dlm->spinlock);

 return out;
}

static int debug_state_open(struct inode *inode, struct file *file)
{
 struct dlm_ctxt *dlm = inode->i_private;
 char *buf = NULL;

 buf = (char *) get_zeroed_page(GFP_NOFS);
 if (!buf)
  goto bail;

 i_size_write(inode, debug_state_print(dlm, buf, PAGE_SIZE - 1));

 file->private_data = buf;

 return 0;
bail:
 return -ENOMEM;
}

static const struct file_operations debug_state_fops = {
 .open =  debug_state_open,
 .release = debug_release,
 .read =  debug_read,
 .llseek = generic_file_llseek,
};
/* end  - debug state funcs */

/* files in subroot */
void dlm_debug_init(struct dlm_ctxt *dlm)
{
 /* for dumping dlm_ctxt */
 debugfs_create_file(DLM_DEBUGFS_DLM_STATE, S_IFREG|S_IRUSR,
       dlm->dlm_debugfs_subroot, dlm, &debug_state_fops);

 /* for dumping lockres */
 debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE, S_IFREG|S_IRUSR,
       dlm->dlm_debugfs_subroot, dlm, &debug_lockres_fops);

 /* for dumping mles */
 debugfs_create_file(DLM_DEBUGFS_MLE_STATE, S_IFREG|S_IRUSR,
       dlm->dlm_debugfs_subroot, dlm, &debug_mle_fops);

 /* for dumping lockres on the purge list */
 debugfs_create_file(DLM_DEBUGFS_PURGE_LIST, S_IFREG|S_IRUSR,
       dlm->dlm_debugfs_subroot, dlm,
       &debug_purgelist_fops);
}

/* subroot - domain dir */
void dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
{
 dlm->dlm_debugfs_subroot = debugfs_create_dir(dlm->name,
            dlm_debugfs_root);
}

void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
{
 debugfs_remove_recursive(dlm->dlm_debugfs_subroot);
}

/* debugfs root */
void dlm_create_debugfs_root(void)
{
 dlm_debugfs_root = debugfs_create_dir(DLM_DEBUGFS_DIR, NULL);
}

void dlm_destroy_debugfs_root(void)
{
 debugfs_remove(dlm_debugfs_root);
}
#endif /* CONFIG_DEBUG_FS */