Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 952 insertions, 0 deletions

diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
new file mode 100644
index 000000000..8fb04ebba
--- /dev/null
+++ b/fs/dlm/debug_fs.c
@@ -0,0 +1,952 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/******************************************************************************
+*******************************************************************************
+**
+**  Copyright (C) 2005-2009 Red Hat, Inc.  All rights reserved.
+**
+**
+*******************************************************************************
+******************************************************************************/
+
+#include <linux/pagemap.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+
+#include "dlm_internal.h"
+#include "midcomms.h"
+#include "lock.h"
+
+#define DLM_DEBUG_BUF_LEN 4096
+static char debug_buf[DLM_DEBUG_BUF_LEN];
+static struct mutex debug_buf_lock;
+
+static struct dentry *dlm_root;
+static struct dentry *dlm_comms;
+
+static char *print_lockmode(int mode)
+{
+	switch (mode) {
+	case DLM_LOCK_IV:
+		return "--";
+	case DLM_LOCK_NL:
+		return "NL";
+	case DLM_LOCK_CR:
+		return "CR";
+	case DLM_LOCK_CW:
+		return "CW";
+	case DLM_LOCK_PR:
+		return "PR";
+	case DLM_LOCK_PW:
+		return "PW";
+	case DLM_LOCK_EX:
+		return "EX";
+	default:
+		return "??";
+	}
+}
+
+static void print_format1_lock(struct seq_file *s, struct dlm_lkb *lkb,
+			       struct dlm_rsb *res)
+{
+	seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
+
+	if (lkb->lkb_status == DLM_LKSTS_CONVERT ||
+	    lkb->lkb_status == DLM_LKSTS_WAITING)
+		seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
+
+	if (lkb->lkb_nodeid) {
+		if (lkb->lkb_nodeid != res->res_nodeid)
+			seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
+				   lkb->lkb_remid);
+		else
+			seq_printf(s, " Master:     %08x", lkb->lkb_remid);
+	}
+
+	if (lkb->lkb_wait_type)
+		seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
+
+	seq_putc(s, '\n');
+}
+
+static void print_format1(struct dlm_rsb *res, struct seq_file *s)
+{
+	struct dlm_lkb *lkb;
+	int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
+
+	lock_rsb(res);
+
+	seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
+
+	for (i = 0; i < res->res_length; i++) {
+		if (isprint(res->res_name[i]))
+			seq_printf(s, "%c", res->res_name[i]);
+		else
+			seq_printf(s, "%c", '.');
+	}
+
+	if (res->res_nodeid > 0)
+		seq_printf(s, "\"\nLocal Copy, Master is node %d\n",
+			   res->res_nodeid);
+	else if (res->res_nodeid == 0)
+		seq_puts(s, "\"\nMaster Copy\n");
+	else if (res->res_nodeid == -1)
+		seq_printf(s, "\"\nLooking up master (lkid %x)\n",
+			   res->res_first_lkid);
+	else
+		seq_printf(s, "\"\nInvalid master %d\n", res->res_nodeid);
+	if (seq_has_overflowed(s))
+		goto out;
+
+	/* Print the LVB: */
+	if (res->res_lvbptr) {
+		seq_puts(s, "LVB: ");
+		for (i = 0; i < lvblen; i++) {
+			if (i == lvblen / 2)
+				seq_puts(s, "\n     ");
+			seq_printf(s, "%02x ",
+				   (unsigned char) res->res_lvbptr[i]);
+		}
+		if (rsb_flag(res, RSB_VALNOTVALID))
+			seq_puts(s, " (INVALID)");
+		seq_putc(s, '\n');
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	root_list = !list_empty(&res->res_root_list);
+	recover_list = !list_empty(&res->res_recover_list);
+
+	if (root_list || recover_list) {
+		seq_printf(s, "Recovery: root %d recover %d flags %lx count %d\n",
+			   root_list, recover_list,
+			   res->res_flags, res->res_recover_locks_count);
+	}
+
+	/* Print the locks attached to this resource */
+	seq_puts(s, "Granted Queue\n");
+	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue) {
+		print_format1_lock(s, lkb, res);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	seq_puts(s, "Conversion Queue\n");
+	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue) {
+		print_format1_lock(s, lkb, res);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	seq_puts(s, "Waiting Queue\n");
+	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue) {
+		print_format1_lock(s, lkb, res);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	if (list_empty(&res->res_lookup))
+		goto out;
+
+	seq_puts(s, "Lookup Queue\n");
+	list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
+		seq_printf(s, "%08x %s",
+			   lkb->lkb_id, print_lockmode(lkb->lkb_rqmode));
+		if (lkb->lkb_wait_type)
+			seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
+		seq_putc(s, '\n');
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+ out:
+	unlock_rsb(res);
+}
+
+static void print_format2_lock(struct seq_file *s, struct dlm_lkb *lkb,
+			       struct dlm_rsb *r)
+{
+	u64 xid = 0;
+	u64 us;
+
+	if (lkb->lkb_flags & DLM_IFL_USER) {
+		if (lkb->lkb_ua)
+			xid = lkb->lkb_ua->xid;
+	}
+
+	/* microseconds since lkb was added to current queue */
+	us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_timestamp));
+
+	/* id nodeid remid pid xid exflags flags sts grmode rqmode time_us
+	   r_nodeid r_len r_name */
+
+	seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %llu %u %d \"%s\"\n",
+		   lkb->lkb_id,
+		   lkb->lkb_nodeid,
+		   lkb->lkb_remid,
+		   lkb->lkb_ownpid,
+		   (unsigned long long)xid,
+		   lkb->lkb_exflags,
+		   lkb->lkb_flags,
+		   lkb->lkb_status,
+		   lkb->lkb_grmode,
+		   lkb->lkb_rqmode,
+		   (unsigned long long)us,
+		   r->res_nodeid,
+		   r->res_length,
+		   r->res_name);
+}
+
+static void print_format2(struct dlm_rsb *r, struct seq_file *s)
+{
+	struct dlm_lkb *lkb;
+
+	lock_rsb(r);
+
+	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
+		print_format2_lock(s, lkb, r);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
+		print_format2_lock(s, lkb, r);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
+		print_format2_lock(s, lkb, r);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+ out:
+	unlock_rsb(r);
+}
+
+static void print_format3_lock(struct seq_file *s, struct dlm_lkb *lkb,
+			      int rsb_lookup)
+{
+	u64 xid = 0;
+
+	if (lkb->lkb_flags & DLM_IFL_USER) {
+		if (lkb->lkb_ua)
+			xid = lkb->lkb_ua->xid;
+	}
+
+	seq_printf(s, "lkb %x %d %x %u %llu %x %x %d %d %d %d %d %d %u %llu %llu\n",
+		   lkb->lkb_id,
+		   lkb->lkb_nodeid,
+		   lkb->lkb_remid,
+		   lkb->lkb_ownpid,
+		   (unsigned long long)xid,
+		   lkb->lkb_exflags,
+		   lkb->lkb_flags,
+		   lkb->lkb_status,
+		   lkb->lkb_grmode,
+		   lkb->lkb_rqmode,
+		   lkb->lkb_last_bast.mode,
+		   rsb_lookup,
+		   lkb->lkb_wait_type,
+		   lkb->lkb_lvbseq,
+		   (unsigned long long)ktime_to_ns(lkb->lkb_timestamp),
+		   (unsigned long long)ktime_to_ns(lkb->lkb_last_bast_time));
+}
+
+static void print_format3(struct dlm_rsb *r, struct seq_file *s)
+{
+	struct dlm_lkb *lkb;
+	int i, lvblen = r->res_ls->ls_lvblen;
+	int print_name = 1;
+
+	lock_rsb(r);
+
+	seq_printf(s, "rsb %p %d %x %lx %d %d %u %d ",
+		   r,
+		   r->res_nodeid,
+		   r->res_first_lkid,
+		   r->res_flags,
+		   !list_empty(&r->res_root_list),
+		   !list_empty(&r->res_recover_list),
+		   r->res_recover_locks_count,
+		   r->res_length);
+	if (seq_has_overflowed(s))
+		goto out;
+
+	for (i = 0; i < r->res_length; i++) {
+		if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
+			print_name = 0;
+	}
+
+	seq_puts(s, print_name ? "str " : "hex");
+
+	for (i = 0; i < r->res_length; i++) {
+		if (print_name)
+			seq_printf(s, "%c", r->res_name[i]);
+		else
+			seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
+	}
+	seq_putc(s, '\n');
+	if (seq_has_overflowed(s))
+		goto out;
+
+	if (!r->res_lvbptr)
+		goto do_locks;
+
+	seq_printf(s, "lvb %u %d", r->res_lvbseq, lvblen);
+
+	for (i = 0; i < lvblen; i++)
+		seq_printf(s, " %02x", (unsigned char)r->res_lvbptr[i]);
+	seq_putc(s, '\n');
+	if (seq_has_overflowed(s))
+		goto out;
+
+ do_locks:
+	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
+		print_format3_lock(s, lkb, 0);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
+		print_format3_lock(s, lkb, 0);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
+		print_format3_lock(s, lkb, 0);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+
+	list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup) {
+		print_format3_lock(s, lkb, 1);
+		if (seq_has_overflowed(s))
+			goto out;
+	}
+ out:
+	unlock_rsb(r);
+}
+
+static void print_format4(struct dlm_rsb *r, struct seq_file *s)
+{
+	int our_nodeid = dlm_our_nodeid();
+	int print_name = 1;
+	int i;
+
+	lock_rsb(r);
+
+	seq_printf(s, "rsb %p %d %d %d %d %lu %lx %d ",
+		   r,
+		   r->res_nodeid,
+		   r->res_master_nodeid,
+		   r->res_dir_nodeid,
+		   our_nodeid,
+		   r->res_toss_time,
+		   r->res_flags,
+		   r->res_length);
+
+	for (i = 0; i < r->res_length; i++) {
+		if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
+			print_name = 0;
+	}
+
+	seq_puts(s, print_name ? "str " : "hex");
+
+	for (i = 0; i < r->res_length; i++) {
+		if (print_name)
+			seq_printf(s, "%c", r->res_name[i]);
+		else
+			seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
+	}
+	seq_putc(s, '\n');
+	unlock_rsb(r);
+}
+
+struct rsbtbl_iter {
+	struct dlm_rsb *rsb;
+	unsigned bucket;
+	int format;
+	int header;
+};
+
+/*
+ * If the buffer is full, seq_printf can be called again, but it
+ * does nothing.  So, the these printing routines periodically check
+ * seq_has_overflowed to avoid wasting too much time trying to print to
+ * a full buffer.
+ */
+
+static int table_seq_show(struct seq_file *seq, void *iter_ptr)
+{
+	struct rsbtbl_iter *ri = iter_ptr;
+
+	switch (ri->format) {
+	case 1:
+		print_format1(ri->rsb, seq);
+		break;
+	case 2:
+		if (ri->header) {
+			seq_puts(seq, "id nodeid remid pid xid exflags flags sts grmode rqmode time_ms r_nodeid r_len r_name\n");
+			ri->header = 0;
+		}
+		print_format2(ri->rsb, seq);
+		break;
+	case 3:
+		if (ri->header) {
+			seq_puts(seq, "version rsb 1.1 lvb 1.1 lkb 1.1\n");
+			ri->header = 0;
+		}
+		print_format3(ri->rsb, seq);
+		break;
+	case 4:
+		if (ri->header) {
+			seq_puts(seq, "version 4 rsb 2\n");
+			ri->header = 0;
+		}
+		print_format4(ri->rsb, seq);
+		break;
+	}
+
+	return 0;
+}
+
+static const struct seq_operations format1_seq_ops;
+static const struct seq_operations format2_seq_ops;
+static const struct seq_operations format3_seq_ops;
+static const struct seq_operations format4_seq_ops;
+
+static void *table_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct rb_root *tree;
+	struct rb_node *node;
+	struct dlm_ls *ls = seq->private;
+	struct rsbtbl_iter *ri;
+	struct dlm_rsb *r;
+	loff_t n = *pos;
+	unsigned bucket, entry;
+	int toss = (seq->op == &format4_seq_ops);
+
+	bucket = n >> 32;
+	entry = n & ((1LL << 32) - 1);
+
+	if (bucket >= ls->ls_rsbtbl_size)
+		return NULL;
+
+	ri = kzalloc(sizeof(*ri), GFP_NOFS);
+	if (!ri)
+		return NULL;
+	if (n == 0)
+		ri->header = 1;
+	if (seq->op == &format1_seq_ops)
+		ri->format = 1;
+	if (seq->op == &format2_seq_ops)
+		ri->format = 2;
+	if (seq->op == &format3_seq_ops)
+		ri->format = 3;
+	if (seq->op == &format4_seq_ops)
+		ri->format = 4;
+
+	tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
+
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
+	if (!RB_EMPTY_ROOT(tree)) {
+		for (node = rb_first(tree); node; node = rb_next(node)) {
+			r = rb_entry(node, struct dlm_rsb, res_hashnode);
+			if (!entry--) {
+				dlm_hold_rsb(r);
+				ri->rsb = r;
+				ri->bucket = bucket;
+				spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+				return ri;
+			}
+		}
+	}
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+
+	/*
+	 * move to the first rsb in the next non-empty bucket
+	 */
+
+	/* zero the entry */
+	n &= ~((1LL << 32) - 1);
+
+	while (1) {
+		bucket++;
+		n += 1LL << 32;
+
+		if (bucket >= ls->ls_rsbtbl_size) {
+			kfree(ri);
+			return NULL;
+		}
+		tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
+
+		spin_lock(&ls->ls_rsbtbl[bucket].lock);
+		if (!RB_EMPTY_ROOT(tree)) {
+			node = rb_first(tree);
+			r = rb_entry(node, struct dlm_rsb, res_hashnode);
+			dlm_hold_rsb(r);
+			ri->rsb = r;
+			ri->bucket = bucket;
+			spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+			*pos = n;
+			return ri;
+		}
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+	}
+}
+
+static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
+{
+	struct dlm_ls *ls = seq->private;
+	struct rsbtbl_iter *ri = iter_ptr;
+	struct rb_root *tree;
+	struct rb_node *next;
+	struct dlm_rsb *r, *rp;
+	loff_t n = *pos;
+	unsigned bucket;
+	int toss = (seq->op == &format4_seq_ops);
+
+	bucket = n >> 32;
+
+	/*
+	 * move to the next rsb in the same bucket
+	 */
+
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
+	rp = ri->rsb;
+	next = rb_next(&rp->res_hashnode);
+
+	if (next) {
+		r = rb_entry(next, struct dlm_rsb, res_hashnode);
+		dlm_hold_rsb(r);
+		ri->rsb = r;
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+		dlm_put_rsb(rp);
+		++*pos;
+		return ri;
+	}
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+	dlm_put_rsb(rp);
+
+	/*
+	 * move to the first rsb in the next non-empty bucket
+	 */
+
+	/* zero the entry */
+	n &= ~((1LL << 32) - 1);
+
+	while (1) {
+		bucket++;
+		n += 1LL << 32;
+
+		if (bucket >= ls->ls_rsbtbl_size) {
+			kfree(ri);
+			++*pos;
+			return NULL;
+		}
+		tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
+
+		spin_lock(&ls->ls_rsbtbl[bucket].lock);
+		if (!RB_EMPTY_ROOT(tree)) {
+			next = rb_first(tree);
+			r = rb_entry(next, struct dlm_rsb, res_hashnode);
+			dlm_hold_rsb(r);
+			ri->rsb = r;
+			ri->bucket = bucket;
+			spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+			*pos = n;
+			return ri;
+		}
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+	}
+}
+
+static void table_seq_stop(struct seq_file *seq, void *iter_ptr)
+{
+	struct rsbtbl_iter *ri = iter_ptr;
+
+	if (ri) {
+		dlm_put_rsb(ri->rsb);
+		kfree(ri);
+	}
+}
+
+static const struct seq_operations format1_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
+static const struct seq_operations format2_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
+static const struct seq_operations format3_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
+static const struct seq_operations format4_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
+static const struct file_operations format1_fops;
+static const struct file_operations format2_fops;
+static const struct file_operations format3_fops;
+static const struct file_operations format4_fops;
+
+static int table_open1(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq;
+	int ret;
+
+	ret = seq_open(file, &format1_seq_ops);
+	if (ret)
+		return ret;
+
+	seq = file->private_data;
+	seq->private = inode->i_private; /* the dlm_ls */
+	return 0;
+}
+
+static int table_open2(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq;
+	int ret;
+
+	ret = seq_open(file, &format2_seq_ops);
+	if (ret)
+		return ret;
+
+	seq = file->private_data;
+	seq->private = inode->i_private; /* the dlm_ls */
+	return 0;
+}
+
+static ssize_t table_write2(struct file *file, const char __user *user_buf,
+			    size_t count, loff_t *ppos)
+{
+	struct seq_file *seq = file->private_data;
+	int n, len, lkb_nodeid, lkb_status, error;
+	char name[DLM_RESNAME_MAXLEN + 1] = {};
+	struct dlm_ls *ls = seq->private;
+	unsigned int lkb_flags;
+	char buf[256] = {};
+	uint32_t lkb_id;
+
+	if (copy_from_user(buf, user_buf,
+			   min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	n = sscanf(buf, "%x %" __stringify(DLM_RESNAME_MAXLEN) "s %x %d %d",
+		   &lkb_id, name, &lkb_flags, &lkb_nodeid, &lkb_status);
+	if (n != 5)
+		return -EINVAL;
+
+	len = strnlen(name, DLM_RESNAME_MAXLEN);
+	error = dlm_debug_add_lkb(ls, lkb_id, name, len, lkb_flags,
+				  lkb_nodeid, lkb_status);
+	if (error)
+		return error;
+
+	return count;
+}
+
+static int table_open3(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq;
+	int ret;
+
+	ret = seq_open(file, &format3_seq_ops);
+	if (ret)
+		return ret;
+
+	seq = file->private_data;
+	seq->private = inode->i_private; /* the dlm_ls */
+	return 0;
+}
+
+static int table_open4(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq;
+	int ret;
+
+	ret = seq_open(file, &format4_seq_ops);
+	if (ret)
+		return ret;
+
+	seq = file->private_data;
+	seq->private = inode->i_private; /* the dlm_ls */
+	return 0;
+}
+
+static const struct file_operations format1_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open1,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+static const struct file_operations format2_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open2,
+	.read    = seq_read,
+	.write   = table_write2,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+static const struct file_operations format3_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open3,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+static const struct file_operations format4_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open4,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+/*
+ * dump lkb's on the ls_waiters list
+ */
+static ssize_t waiters_read(struct file *file, char __user *userbuf,
+			    size_t count, loff_t *ppos)
+{
+	struct dlm_ls *ls = file->private_data;
+	struct dlm_lkb *lkb;
+	size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
+
+	mutex_lock(&debug_buf_lock);
+	mutex_lock(&ls->ls_waiters_mutex);
+	memset(debug_buf, 0, sizeof(debug_buf));
+
+	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
+		ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
+			       lkb->lkb_id, lkb->lkb_wait_type,
+			       lkb->lkb_nodeid, lkb->lkb_resource->res_name);
+		if (ret >= len - pos)
+			break;
+		pos += ret;
+	}
+	mutex_unlock(&ls->ls_waiters_mutex);
+
+	rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
+	mutex_unlock(&debug_buf_lock);
+	return rv;
+}
+
+static ssize_t waiters_write(struct file *file, const char __user *user_buf,
+			     size_t count, loff_t *ppos)
+{
+	struct dlm_ls *ls = file->private_data;
+	int mstype, to_nodeid;
+	char buf[128] = {};
+	uint32_t lkb_id;
+	int n, error;
+
+	if (copy_from_user(buf, user_buf,
+			   min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	n = sscanf(buf, "%x %d %d", &lkb_id, &mstype, &to_nodeid);
+	if (n != 3)
+		return -EINVAL;
+
+	error = dlm_debug_add_lkb_to_waiters(ls, lkb_id, mstype, to_nodeid);
+	if (error)
+		return error;
+
+	return count;
+}
+
+static const struct file_operations waiters_fops = {
+	.owner   = THIS_MODULE,
+	.open    = simple_open,
+	.read    = waiters_read,
+	.write   = waiters_write,
+	.llseek  = default_llseek,
+};
+
+void dlm_delete_debug_file(struct dlm_ls *ls)
+{
+	debugfs_remove(ls->ls_debug_rsb_dentry);
+	debugfs_remove(ls->ls_debug_waiters_dentry);
+	debugfs_remove(ls->ls_debug_locks_dentry);
+	debugfs_remove(ls->ls_debug_all_dentry);
+	debugfs_remove(ls->ls_debug_toss_dentry);
+}
+
+static int dlm_state_show(struct seq_file *file, void *offset)
+{
+	seq_printf(file, "%s\n", dlm_midcomms_state(file->private));
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(dlm_state);
+
+static int dlm_flags_show(struct seq_file *file, void *offset)
+{
+	seq_printf(file, "%lu\n", dlm_midcomms_flags(file->private));
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(dlm_flags);
+
+static int dlm_send_queue_cnt_show(struct seq_file *file, void *offset)
+{
+	seq_printf(file, "%d\n", dlm_midcomms_send_queue_cnt(file->private));
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(dlm_send_queue_cnt);
+
+static int dlm_version_show(struct seq_file *file, void *offset)
+{
+	seq_printf(file, "0x%08x\n", dlm_midcomms_version(file->private));
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(dlm_version);
+
+static ssize_t dlm_rawmsg_write(struct file *fp, const char __user *user_buf,
+				size_t count, loff_t *ppos)
+{
+	void *buf;
+	int ret;
+
+	if (count > PAGE_SIZE || count < sizeof(struct dlm_header))
+		return -EINVAL;
+
+	buf = kmalloc(PAGE_SIZE, GFP_NOFS);
+	if (!buf)
+		return -ENOMEM;
+
+	if (copy_from_user(buf, user_buf, count)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	ret = dlm_midcomms_rawmsg_send(fp->private_data, buf, count);
+	if (ret)
+		goto out;
+
+	kfree(buf);
+	return count;
+
+out:
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations dlm_rawmsg_fops = {
+	.open	= simple_open,
+	.write	= dlm_rawmsg_write,
+	.llseek	= no_llseek,
+};
+
+void *dlm_create_debug_comms_file(int nodeid, void *data)
+{
+	struct dentry *d_node;
+	char name[256];
+
+	memset(name, 0, sizeof(name));
+	snprintf(name, 256, "%d", nodeid);
+
+	d_node = debugfs_create_dir(name, dlm_comms);
+	debugfs_create_file("state", 0444, d_node, data, &dlm_state_fops);
+	debugfs_create_file("flags", 0444, d_node, data, &dlm_flags_fops);
+	debugfs_create_file("send_queue_count", 0444, d_node, data,
+			    &dlm_send_queue_cnt_fops);
+	debugfs_create_file("version", 0444, d_node, data, &dlm_version_fops);
+	debugfs_create_file("rawmsg", 0200, d_node, data, &dlm_rawmsg_fops);
+
+	return d_node;
+}
+
+void dlm_delete_debug_comms_file(void *ctx)
+{
+	debugfs_remove(ctx);
+}
+
+void dlm_create_debug_file(struct dlm_ls *ls)
+{
+	char name[DLM_LOCKSPACE_LEN + 8];
+
+	/* format 1 */
+
+	ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
+						      S_IFREG | S_IRUGO,
+						      dlm_root,
+						      ls,
+						      &format1_fops);
+
+	/* format 2 */
+
+	memset(name, 0, sizeof(name));
+	snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_locks", ls->ls_name);
+
+	ls->ls_debug_locks_dentry = debugfs_create_file(name,
+							0644,
+							dlm_root,
+							ls,
+							&format2_fops);
+
+	/* format 3 */
+
+	memset(name, 0, sizeof(name));
+	snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_all", ls->ls_name);
+
+	ls->ls_debug_all_dentry = debugfs_create_file(name,
+						      S_IFREG | S_IRUGO,
+						      dlm_root,
+						      ls,
+						      &format3_fops);
+
+	/* format 4 */
+
+	memset(name, 0, sizeof(name));
+	snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_toss", ls->ls_name);
+
+	ls->ls_debug_toss_dentry = debugfs_create_file(name,
+						       S_IFREG | S_IRUGO,
+						       dlm_root,
+						       ls,
+						       &format4_fops);
+
+	memset(name, 0, sizeof(name));
+	snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_waiters", ls->ls_name);
+
+	ls->ls_debug_waiters_dentry = debugfs_create_file(name,
+							  0644,
+							  dlm_root,
+							  ls,
+							  &waiters_fops);
+}
+
+void __init dlm_register_debugfs(void)
+{
+	mutex_init(&debug_buf_lock);
+	dlm_root = debugfs_create_dir("dlm", NULL);
+	dlm_comms = debugfs_create_dir("comms", dlm_root);
+}
+
+void dlm_unregister_debugfs(void)
+{
+	debugfs_remove(dlm_root);
+}
+