root/fs/ocfs2/dlm/dlmdebug.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 */