Initial import

1 files changed, 1000 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
new file mode 100644
index 000000000..825136070
--- /dev/null
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -0,0 +1,1000 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * dlmdebug.c
+ *
+ * debug functionality for the dlm
+ *
+ * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ */
+
+#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 "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)),
+	       atomic_read(&lock->lock_refs.refcount),
+	       (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, atomic_read(&res->refs.refcount),
+	       list_empty(&res->purge) ? "no" : "yes");
+	printk("  on dirty list: %s, on reco list: %s, "
+	       "migrating pending: %s\n",
+	       list_empty(&res->dirty) ? "no" : "yes",
+	       list_empty(&res->recovering) ? "no" : "yes",
+	       res->migration_pending ? "yes" : "no");
+	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",
+};
+
+static const char *dlm_errmsgs[] = {
+	[DLM_NORMAL] = 			"request in progress",
+	[DLM_GRANTED] = 		"request granted",
+	[DLM_DENIED] = 			"request denied",
+	[DLM_DENIED_NOLOCKS] = 		"request denied, out of system resources",
+	[DLM_WORKING] = 		"async request in progress",
+	[DLM_BLOCKED] = 		"lock request blocked",
+	[DLM_BLOCKED_ORPHAN] = 		"lock request blocked by a orphan lock",
+	[DLM_DENIED_GRACE_PERIOD] = 	"topological change in progress",
+	[DLM_SYSERR] = 			"system error",
+	[DLM_NOSUPPORT] = 		"unsupported",
+	[DLM_CANCELGRANT] = 		"can't cancel convert: already granted",
+	[DLM_IVLOCKID] = 		"bad lockid",
+	[DLM_SYNC] = 			"synchronous request granted",
+	[DLM_BADTYPE] = 		"bad resource type",
+	[DLM_BADRESOURCE] = 		"bad resource handle",
+	[DLM_MAXHANDLES] = 		"no more resource handles",
+	[DLM_NOCLINFO] = 		"can't contact cluster manager",
+	[DLM_NOLOCKMGR] = 		"can't contact lock manager",
+	[DLM_NOPURGED] = 		"can't contact purge daemon",
+	[DLM_BADARGS] = 		"bad api args",
+	[DLM_VOID] = 			"no status",
+	[DLM_NOTQUEUED] = 		"NOQUEUE was specified and request failed",
+	[DLM_IVBUFLEN] = 		"invalid resource name length",
+	[DLM_CVTUNGRANT] = 		"attempted to convert ungranted lock",
+	[DLM_BADPARAM] = 		"invalid lock mode specified",
+	[DLM_VALNOTVALID] = 		"value block has been invalidated",
+	[DLM_REJECTED] = 		"request rejected, unrecognized client",
+	[DLM_ABORT] = 			"blocked lock request cancelled",
+	[DLM_CANCEL] = 			"conversion request cancelled",
+	[DLM_IVRESHANDLE] = 		"invalid resource handle",
+	[DLM_DEADLOCK] = 		"deadlock recovery refused this request",
+	[DLM_DENIED_NOASTS] = 		"failed to allocate AST",
+	[DLM_FORWARD] = 		"request must wait for primary's response",
+	[DLM_TIMEOUT] = 		"timeout value for lock has expired",
+	[DLM_IVGROUPID] = 		"invalid group specification",
+	[DLM_VERS_CONFLICT] = 		"version conflicts prevent request handling",
+	[DLM_BAD_DEVICE_PATH] = 	"Locks device does not exist or path wrong",
+	[DLM_NO_DEVICE_PERMISSION] = 	"Client has insufficient perms for device",
+	[DLM_NO_CONTROL_DEVICE] = 	"Cannot set options on opened device ",
+	[DLM_RECOVERING] = 		"lock resource being recovered",
+	[DLM_MIGRATING] = 		"lock resource being migrated",
+	[DLM_MAXSTATS] = 		"invalid error number",
+};
+
+const char *dlm_errmsg(enum dlm_status err)
+{
+	if (err >= DLM_MAXSTATS || err < 0)
+		return dlm_errmsgs[DLM_MAXSTATS];
+	return dlm_errmsgs[err];
+}
+EXPORT_SYMBOL_GPL(dlm_errmsg);
+
+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 += snprintf(buf + out, len - out, "%.*s%08x",
+				OCFS2_DENTRY_LOCK_INO_START - 1, lockname,
+				(unsigned int)be64_to_cpu(inode_blkno_be));
+	} else
+		out += snprintf(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 += snprintf(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 += snprintf(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,
+			atomic_read(&mle->mle_refs.refcount));
+
+	out += snprintf(buf + out, len - out, "Maybe=");
+	out += stringify_nodemap(mle->maybe_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	out += snprintf(buf + out, len - out, "Vote=");
+	out += stringify_nodemap(mle->vote_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	out += snprintf(buf + out, len - out, "Response=");
+	out += stringify_nodemap(mle->response_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	out += snprintf(buf + out, len - out, "Node=");
+	out += stringify_nodemap(mle->node_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	out += snprintf(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_NOFS);
+	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 void dlm_debug_free(struct kref *kref)
+{
+	struct dlm_debug_ctxt *dc;
+
+	dc = container_of(kref, struct dlm_debug_ctxt, debug_refcnt);
+
+	kfree(dc);
+}
+
+static void dlm_debug_put(struct dlm_debug_ctxt *dc)
+{
+	if (dc)
+		kref_put(&dc->debug_refcnt, dlm_debug_free);
+}
+
+static void dlm_debug_get(struct dlm_debug_ctxt *dc)
+{
+	kref_get(&dc->debug_refcnt);
+}
+
+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 += snprintf(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 += snprintf(buf + out, len - out, "\t%ld\n",
+				(jiffies - res->last_used)/HZ);
+		spin_unlock(&res->spinlock);
+	}
+	spin_unlock(&dlm->spinlock);
+
+	out += snprintf(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 += snprintf(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 += snprintf(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 = snprintf(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,
+		       atomic_read(&lock->lock_refs.refcount));
+	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 += snprintf(buf + out, len - out, "NAME:");
+	out += stringify_lockname(res->lockname.name, res->lockname.len,
+				  buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+#define DEBUG_LRES_VERSION	1
+	out += snprintf(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),
+			atomic_read(&res->refs.refcount));
+
+	/* refmap */
+	out += snprintf(buf + out, len - out, "RMAP:");
+	out += stringify_nodemap(res->refmap, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	/* lvb */
+	out += snprintf(buf + out, len - out, "LVBX:");
+	for (i = 0; i < DLM_LVB_LEN; i++)
+		out += snprintf(buf + out, len - out,
+					"%02x", (unsigned char)res->lvb[i]);
+	out += snprintf(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 += snprintf(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;
+	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(res, track_list, tracking) {
+		if (&res->tracking == &dlm->tracking_list)
+			res = NULL;
+		else
+			dlm_lockres_get(res);
+		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 += snprintf(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 += snprintf(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 += snprintf(buf + out, len - out,
+			"Number of Joins: %d  Joining Node: %d\n",
+			dlm->num_joins, dlm->joining_node);
+
+	/* Domain Map: xx xx xx */
+	out += snprintf(buf + out, len - out, "Domain Map: ");
+	out += stringify_nodemap(dlm->domain_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	/* Exit Domain Map: xx xx xx */
+	out += snprintf(buf + out, len - out, "Exit Domain Map: ");
+	out += stringify_nodemap(dlm->exit_domain_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	/* Live Map: xx xx xx */
+	out += snprintf(buf + out, len - out, "Live Map: ");
+	out += stringify_nodemap(dlm->live_nodes_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	/* Lock Resources: xxx (xxx) */
+	out += snprintf(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 += snprintf(buf + out, len - out,
+			"MLEs: %d (%d)\n", cur_mles, tot_mles);
+
+	/*  Blocking: xxx (xxx) */
+	out += snprintf(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 += snprintf(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 += snprintf(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 += snprintf(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 += snprintf(buf + out, len - out,
+			"Purge Count: %d  Refs: %d\n", dlm->purge_count,
+			atomic_read(&dlm->dlm_refs.refcount));
+
+	/* Dead Node: xxx */
+	out += snprintf(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 += snprintf(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 += snprintf(buf + out, len - out, "Recovery Map: ");
+	out += stringify_nodemap(dlm->recovery_map, O2NM_MAX_NODES,
+				 buf + out, len - out);
+	out += snprintf(buf + out, len - out, "\n");
+
+	/* Recovery Node State: */
+	out += snprintf(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 += snprintf(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 */
+int dlm_debug_init(struct dlm_ctxt *dlm)
+{
+	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
+
+	/* for dumping dlm_ctxt */
+	dc->debug_state_dentry = debugfs_create_file(DLM_DEBUGFS_DLM_STATE,
+						     S_IFREG|S_IRUSR,
+						     dlm->dlm_debugfs_subroot,
+						     dlm, &debug_state_fops);
+	if (!dc->debug_state_dentry) {
+		mlog_errno(-ENOMEM);
+		goto bail;
+	}
+
+	/* for dumping lockres */
+	dc->debug_lockres_dentry =
+			debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE,
+					    S_IFREG|S_IRUSR,
+					    dlm->dlm_debugfs_subroot,
+					    dlm, &debug_lockres_fops);
+	if (!dc->debug_lockres_dentry) {
+		mlog_errno(-ENOMEM);
+		goto bail;
+	}
+
+	/* for dumping mles */
+	dc->debug_mle_dentry = debugfs_create_file(DLM_DEBUGFS_MLE_STATE,
+						   S_IFREG|S_IRUSR,
+						   dlm->dlm_debugfs_subroot,
+						   dlm, &debug_mle_fops);
+	if (!dc->debug_mle_dentry) {
+		mlog_errno(-ENOMEM);
+		goto bail;
+	}
+
+	/* for dumping lockres on the purge list */
+	dc->debug_purgelist_dentry =
+			debugfs_create_file(DLM_DEBUGFS_PURGE_LIST,
+					    S_IFREG|S_IRUSR,
+					    dlm->dlm_debugfs_subroot,
+					    dlm, &debug_purgelist_fops);
+	if (!dc->debug_purgelist_dentry) {
+		mlog_errno(-ENOMEM);
+		goto bail;
+	}
+
+	dlm_debug_get(dc);
+	return 0;
+
+bail:
+	dlm_debug_shutdown(dlm);
+	return -ENOMEM;
+}
+
+void dlm_debug_shutdown(struct dlm_ctxt *dlm)
+{
+	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
+
+	if (dc) {
+		debugfs_remove(dc->debug_purgelist_dentry);
+		debugfs_remove(dc->debug_mle_dentry);
+		debugfs_remove(dc->debug_lockres_dentry);
+		debugfs_remove(dc->debug_state_dentry);
+		dlm_debug_put(dc);
+	}
+}
+
+/* subroot - domain dir */
+int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
+{
+	dlm->dlm_debugfs_subroot = debugfs_create_dir(dlm->name,
+						      dlm_debugfs_root);
+	if (!dlm->dlm_debugfs_subroot) {
+		mlog_errno(-ENOMEM);
+		goto bail;
+	}
+
+	dlm->dlm_debug_ctxt = kzalloc(sizeof(struct dlm_debug_ctxt),
+				      GFP_KERNEL);
+	if (!dlm->dlm_debug_ctxt) {
+		mlog_errno(-ENOMEM);
+		goto bail;
+	}
+	kref_init(&dlm->dlm_debug_ctxt->debug_refcnt);
+
+	return 0;
+bail:
+	dlm_destroy_debugfs_subroot(dlm);
+	return -ENOMEM;
+}
+
+void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
+{
+	debugfs_remove(dlm->dlm_debugfs_subroot);
+}
+
+/* debugfs root */
+int dlm_create_debugfs_root(void)
+{
+	dlm_debugfs_root = debugfs_create_dir(DLM_DEBUGFS_DIR, NULL);
+	if (!dlm_debugfs_root) {
+		mlog_errno(-ENOMEM);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void dlm_destroy_debugfs_root(void)
+{
+	debugfs_remove(dlm_debugfs_root);
+}
+#endif	/* CONFIG_DEBUG_FS */