[mirror_ubuntu-artful-kernel.git] / fs / dlm / debug_fs.c

/******************************************************************************
*******************************************************************************
**
**  Copyright (C) 2005 Red Hat, Inc.  All rights reserved.
**
**  This copyrighted material is made available to anyone wishing to use,
**  modify, copy, or redistribute it subject to the terms and conditions
**  of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/

#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>

#include "dlm_internal.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;

struct rsb_iter {
	int entry;
	int master;
	int header;
	struct dlm_ls *ls;
	struct list_head *next;
	struct dlm_rsb *rsb;
};

/*
 * dump all rsb's in the lockspace hash table
 */

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_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_printf(s, "\n");
}

static int print_resource(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_printf(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);

	/* Print the LVB: */
	if (res->res_lvbptr) {
		seq_printf(s, "LVB: ");
		for (i = 0; i < lvblen; i++) {
			if (i == lvblen / 2)
				seq_printf(s, "\n     ");
			seq_printf(s, "%02x ",
				   (unsigned char) res->res_lvbptr[i]);
		}
		if (rsb_flag(res, RSB_VALNOTVALID))
			seq_printf(s, " (INVALID)");
		seq_printf(s, "\n");
	}

	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_printf(s, "Granted Queue\n");
	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
		print_lock(s, lkb, res);

	seq_printf(s, "Conversion Queue\n");
	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
		print_lock(s, lkb, res);

	seq_printf(s, "Waiting Queue\n");
	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
		print_lock(s, lkb, res);

	if (list_empty(&res->res_lookup))
		goto out;

	seq_printf(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_printf(s, "\n");
	}
 out:
	unlock_rsb(res);
	return 0;
}

static void print_master_lock(struct seq_file *s, struct dlm_lkb *lkb,
			      struct dlm_rsb *r)
{
	struct dlm_user_args *ua;
	unsigned int waiting = 0;
	uint64_t xid = 0;

	if (lkb->lkb_flags & DLM_IFL_USER) {
		ua = (struct dlm_user_args *) lkb->lkb_astparam;
		if (ua)
			xid = ua->xid;
	}

	if (lkb->lkb_timestamp)
		waiting = jiffies_to_msecs(jiffies - lkb->lkb_timestamp);

	/* id nodeid remid pid xid flags sts grmode rqmode time_ms len name */

	seq_printf(s, "%x %d %x %u %llu %x %d %d %d %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_status,
		   lkb->lkb_grmode,
		   lkb->lkb_rqmode,
		   waiting,
		   r->res_length,
		   r->res_name);
}

static int print_master_resource(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_master_lock(s, lkb, r);

	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
		print_master_lock(s, lkb, r);

	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
		print_master_lock(s, lkb, r);

	unlock_rsb(r);
	return 0;
}

static int rsb_iter_next(struct rsb_iter *ri)
{
	struct dlm_ls *ls = ri->ls;
	int i;

	if (!ri->next) {
 top:
		/* Find the next non-empty hash bucket */
		for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
			read_lock(&ls->ls_rsbtbl[i].lock);
			if (!list_empty(&ls->ls_rsbtbl[i].list)) {
				ri->next = ls->ls_rsbtbl[i].list.next;
				ri->rsb = list_entry(ri->next, struct dlm_rsb,
							res_hashchain);
				dlm_hold_rsb(ri->rsb);
				read_unlock(&ls->ls_rsbtbl[i].lock);
				break;
			}
			read_unlock(&ls->ls_rsbtbl[i].lock);
                }
		ri->entry = i;

		if (ri->entry >= ls->ls_rsbtbl_size)
			return 1;
	} else {
		struct dlm_rsb *old = ri->rsb;
		i = ri->entry;
		read_lock(&ls->ls_rsbtbl[i].lock);
		ri->next = ri->next->next;
		if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
			/* End of list - move to next bucket */
			ri->next = NULL;
			ri->entry++;
			read_unlock(&ls->ls_rsbtbl[i].lock);
			dlm_put_rsb(old);
			goto top;
                }
		ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
		dlm_hold_rsb(ri->rsb);
		read_unlock(&ls->ls_rsbtbl[i].lock);
		dlm_put_rsb(old);
	}

	return 0;
}

static void rsb_iter_free(struct rsb_iter *ri)
{
	kfree(ri);
}

static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
{
	struct rsb_iter *ri;

	ri = kzalloc(sizeof *ri, GFP_KERNEL);
	if (!ri)
		return NULL;

	ri->ls = ls;
	ri->entry = 0;
	ri->next = NULL;

	if (rsb_iter_next(ri)) {
		rsb_iter_free(ri);
		return NULL;
	}

	return ri;
}

static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
{
	struct rsb_iter *ri;
	loff_t n = *pos;

	ri = rsb_iter_init(file->private);
	if (!ri)
		return NULL;

	while (n--) {
		if (rsb_iter_next(ri)) {
			rsb_iter_free(ri);
			return NULL;
		}
	}

	return ri;
}

static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
{
	struct rsb_iter *ri = iter_ptr;

	(*pos)++;

	if (rsb_iter_next(ri)) {
		rsb_iter_free(ri);
		return NULL;
	}

	return ri;
}

static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
{
	/* nothing for now */
}

static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
{
	struct rsb_iter *ri = iter_ptr;

	if (ri->master) {
		if (ri->header) {
			seq_printf(file, "id nodeid remid pid xid flags sts "
					 "grmode rqmode time_ms len name\n");
			ri->header = 0;
		}
		if (is_master(ri->rsb))
			print_master_resource(ri->rsb, file);
	} else {
		print_resource(ri->rsb, file);
	}

	return 0;
}

static struct seq_operations rsb_seq_ops = {
	.start = rsb_seq_start,
	.next  = rsb_seq_next,
	.stop  = rsb_seq_stop,
	.show  = rsb_seq_show,
};

static int rsb_open(struct inode *inode, struct file *file)
{
	struct seq_file *seq;
	int ret;

	ret = seq_open(file, &rsb_seq_ops);
	if (ret)
		return ret;

	seq = file->private_data;
	seq->private = inode->i_private;

	return 0;
}

static const struct file_operations rsb_fops = {
	.owner   = THIS_MODULE,
	.open    = rsb_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release
};

/*
 * Dump master lock state
 */

static struct rsb_iter *master_iter_init(struct dlm_ls *ls, loff_t *pos)
{
	struct rsb_iter *ri;

	ri = kzalloc(sizeof *ri, GFP_KERNEL);
	if (!ri)
		return NULL;

	ri->ls = ls;
	ri->entry = 0;
	ri->next = NULL;
	ri->master = 1;

	if (*pos == 0)
		ri->header = 1;

	if (rsb_iter_next(ri)) {
		rsb_iter_free(ri);
		return NULL;
	}

	return ri;
}

static void *master_seq_start(struct seq_file *file, loff_t *pos)
{
	struct rsb_iter *ri;
	loff_t n = *pos;

	ri = master_iter_init(file->private, pos);
	if (!ri)
		return NULL;

	while (n--) {
		if (rsb_iter_next(ri)) {
			rsb_iter_free(ri);
			return NULL;
		}
	}

	return ri;
}

static struct seq_operations master_seq_ops = {
	.start = master_seq_start,
	.next  = rsb_seq_next,
	.stop  = rsb_seq_stop,
	.show  = rsb_seq_show,
};

static int master_open(struct inode *inode, struct file *file)
{
	struct seq_file *seq;
	int ret;

	ret = seq_open(file, &master_seq_ops);
	if (ret)
		return ret;

	seq = file->private_data;
	seq->private = inode->i_private;

	return 0;
}

static const struct file_operations master_fops = {
	.owner   = THIS_MODULE,
	.open    = master_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release
};

/*
 * dump lkb's on the ls_waiters list
 */

static int waiters_open(struct inode *inode, struct file *file)
{
	file->private_data = inode->i_private;
	return 0;
}

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 const struct file_operations waiters_fops = {
	.owner   = THIS_MODULE,
	.open    = waiters_open,
	.read    = waiters_read
};

int dlm_create_debug_file(struct dlm_ls *ls)
{
	char name[DLM_LOCKSPACE_LEN+8];

	ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
						      S_IFREG | S_IRUGO,
						      dlm_root,
						      ls,
						      &rsb_fops);
	if (!ls->ls_debug_rsb_dentry)
		return -ENOMEM;

	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,
							  S_IFREG | S_IRUGO,
							  dlm_root,
							  ls,
							  &waiters_fops);
	if (!ls->ls_debug_waiters_dentry) {
		debugfs_remove(ls->ls_debug_rsb_dentry);
		return -ENOMEM;
	}

	memset(name, 0, sizeof(name));
	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_master", ls->ls_name);

	ls->ls_debug_master_dentry = debugfs_create_file(name,
							 S_IFREG | S_IRUGO,
							 dlm_root,
							 ls,
							 &master_fops);
	if (!ls->ls_debug_master_dentry) {
		debugfs_remove(ls->ls_debug_waiters_dentry);
		debugfs_remove(ls->ls_debug_rsb_dentry);
		return -ENOMEM;
	}

	return 0;
}

void dlm_delete_debug_file(struct dlm_ls *ls)
{
	if (ls->ls_debug_rsb_dentry)
		debugfs_remove(ls->ls_debug_rsb_dentry);
	if (ls->ls_debug_waiters_dentry)
		debugfs_remove(ls->ls_debug_waiters_dentry);
	if (ls->ls_debug_master_dentry)
		debugfs_remove(ls->ls_debug_master_dentry);
}

int dlm_register_debugfs(void)
{
	mutex_init(&debug_buf_lock);
	dlm_root = debugfs_create_dir("dlm", NULL);
	return dlm_root ? 0 : -ENOMEM;
}

void dlm_unregister_debugfs(void)
{
	debugfs_remove(dlm_root);
}
Commit	Line	Data
e7fd4179 DT	1	/******************************************************************************
	2	*******************************************************************************
	3	**
	4	** Copyright (C) 2005 Red Hat, Inc. All rights reserved.
	5	**
	6	** This copyrighted material is made available to anyone wishing to use,
	7	** modify, copy, or redistribute it subject to the terms and conditions
	8	** of the GNU General Public License v.2.
	9	**
	10	*******************************************************************************
	11	******************************************************************************/
	12
	13	#include <linux/pagemap.h>
	14	#include <linux/seq_file.h>
	15	#include <linux/module.h>
	16	#include <linux/ctype.h>
	17	#include <linux/debugfs.h>
	18
	19	#include "dlm_internal.h"
916297aa	20	#include "lock.h"
e7fd4179	21
5de6319b DT	22	#define DLM_DEBUG_BUF_LEN 4096
	23	static char debug_buf[DLM_DEBUG_BUF_LEN];
	24	static struct mutex debug_buf_lock;
e7fd4179 DT	25
	26	static struct dentry *dlm_root;
	27
	28	struct rsb_iter {
	29	int entry;
9dd592d7 DT	30	int master;
9dd592d7 DT	31	int header;
e7fd4179 DT	32	struct dlm_ls *ls;
	33	struct list_head *next;
	34	struct dlm_rsb *rsb;
	35	};
	36
5de6319b DT	37	/*
	38	* dump all rsb's in the lockspace hash table
	39	*/
	40
e7fd4179 DT	41	static char *print_lockmode(int mode)
	42	{
	43	switch (mode) {
	44	case DLM_LOCK_IV:
	45	return "--";
	46	case DLM_LOCK_NL:
	47	return "NL";
	48	case DLM_LOCK_CR:
	49	return "CR";
	50	case DLM_LOCK_CW:
	51	return "CW";
	52	case DLM_LOCK_PR:
	53	return "PR";
	54	case DLM_LOCK_PW:
	55	return "PW";
	56	case DLM_LOCK_EX:
	57	return "EX";
	58	default:
	59	return "??";
	60	}
	61	}
	62
	63	static void print_lock(struct seq_file s, struct dlm_lkb lkb,
	64	struct dlm_rsb *res)
	65	{
	66	seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
	67
	68	if (lkb->lkb_status == DLM_LKSTS_CONVERT
	69	\|\| lkb->lkb_status == DLM_LKSTS_WAITING)
	70	seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
	71
e7fd4179 DT	72	if (lkb->lkb_nodeid) {
	73	if (lkb->lkb_nodeid != res->res_nodeid)
	74	seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
	75	lkb->lkb_remid);
	76	else
	77	seq_printf(s, " Master: %08x", lkb->lkb_remid);
	78	}
	79
	80	if (lkb->lkb_wait_type)
	81	seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
	82
	83	seq_printf(s, "\n");
	84	}
	85
	86	static int print_resource(struct dlm_rsb res, struct seq_file s)
	87	{
	88	struct dlm_lkb *lkb;
5de6319b	89	int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
e7fd4179	90
9dd592d7 DT	91	lock_rsb(res);
9dd592d7 DT	92
e7fd4179 DT	93	seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
	94	for (i = 0; i < res->res_length; i++) {
	95	if (isprint(res->res_name[i]))
	96	seq_printf(s, "%c", res->res_name[i]);
	97	else
	98	seq_printf(s, "%c", '.');
	99	}
	100	if (res->res_nodeid > 0)
	101	seq_printf(s, "\" \nLocal Copy, Master is node %d\n",
	102	res->res_nodeid);
	103	else if (res->res_nodeid == 0)
	104	seq_printf(s, "\" \nMaster Copy\n");
	105	else if (res->res_nodeid == -1)
	106	seq_printf(s, "\" \nLooking up master (lkid %x)\n",
	107	res->res_first_lkid);
	108	else
	109	seq_printf(s, "\" \nInvalid master %d\n", res->res_nodeid);
	110
	111	/* Print the LVB: */
	112	if (res->res_lvbptr) {
	113	seq_printf(s, "LVB: ");
	114	for (i = 0; i < lvblen; i++) {
	115	if (i == lvblen / 2)
	116	seq_printf(s, "\n ");
	117	seq_printf(s, "%02x ",
	118	(unsigned char) res->res_lvbptr[i]);
	119	}
	120	if (rsb_flag(res, RSB_VALNOTVALID))
	121	seq_printf(s, " (INVALID)");
	122	seq_printf(s, "\n");
	123	}
	124
5de6319b DT	125	root_list = !list_empty(&res->res_root_list);
	126	recover_list = !list_empty(&res->res_recover_list);
	127
	128	if (root_list \|\| recover_list) {
	129	seq_printf(s, "Recovery: root %d recover %d flags %lx "
	130	"count %d\n", root_list, recover_list,
20abf975	131	res->res_flags, res->res_recover_locks_count);
5de6319b DT	132	}
5de6319b DT	133
e7fd4179 DT	134	/* Print the locks attached to this resource */
	135	seq_printf(s, "Granted Queue\n");
	136	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
	137	print_lock(s, lkb, res);
	138
	139	seq_printf(s, "Conversion Queue\n");
	140	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
	141	print_lock(s, lkb, res);
	142
	143	seq_printf(s, "Waiting Queue\n");
	144	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
	145	print_lock(s, lkb, res);
	146
5de6319b DT	147	if (list_empty(&res->res_lookup))
	148	goto out;
	149
	150	seq_printf(s, "Lookup Queue\n");
	151	list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
	152	seq_printf(s, "%08x %s", lkb->lkb_id,
	153	print_lockmode(lkb->lkb_rqmode));
	154	if (lkb->lkb_wait_type)
	155	seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
	156	seq_printf(s, "\n");
	157	}
	158	out:
9dd592d7 DT	159	unlock_rsb(res);
	160	return 0;
	161	}
	162
	163	static void print_master_lock(struct seq_file s, struct dlm_lkb lkb,
	164	struct dlm_rsb *r)
	165	{
	166	struct dlm_user_args *ua;
	167	unsigned int waiting = 0;
	168	uint64_t xid = 0;
	169
	170	if (lkb->lkb_flags & DLM_IFL_USER) {
	171	ua = (struct dlm_user_args *) lkb->lkb_astparam;
	172	if (ua)
	173	xid = ua->xid;
	174	}
	175
	176	if (lkb->lkb_timestamp)
	177	waiting = jiffies_to_msecs(jiffies - lkb->lkb_timestamp);
	178
	179	/* id nodeid remid pid xid flags sts grmode rqmode time_ms len name */
	180
	181	seq_printf(s, "%x %d %x %u %llu %x %d %d %d %u %d \"%s\"\n",
	182	lkb->lkb_id,
	183	lkb->lkb_nodeid,
	184	lkb->lkb_remid,
	185	lkb->lkb_ownpid,
	186	(unsigned long long)xid,
	187	lkb->lkb_exflags,
	188	lkb->lkb_status,
	189	lkb->lkb_grmode,
	190	lkb->lkb_rqmode,
	191	waiting,
	192	r->res_length,
	193	r->res_name);
	194	}
	195
	196	static int print_master_resource(struct dlm_rsb r, struct seq_file s)
	197	{
	198	struct dlm_lkb *lkb;
	199
	200	lock_rsb(r);
	201
	202	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
	203	print_master_lock(s, lkb, r);
	204
	205	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
	206	print_master_lock(s, lkb, r);
	207
	208	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
	209	print_master_lock(s, lkb, r);
	210
	211	unlock_rsb(r);
e7fd4179 DT	212	return 0;
	213	}
	214
	215	static int rsb_iter_next(struct rsb_iter *ri)
	216	{
	217	struct dlm_ls *ls = ri->ls;
	218	int i;
	219
	220	if (!ri->next) {
	221	top:
	222	/* Find the next non-empty hash bucket */
	223	for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
	224	read_lock(&ls->ls_rsbtbl[i].lock);
	225	if (!list_empty(&ls->ls_rsbtbl[i].list)) {
	226	ri->next = ls->ls_rsbtbl[i].list.next;
916297aa JB	227	ri->rsb = list_entry(ri->next, struct dlm_rsb,
	228	res_hashchain);
	229	dlm_hold_rsb(ri->rsb);
e7fd4179 DT	230	read_unlock(&ls->ls_rsbtbl[i].lock);
	231	break;
	232	}
	233	read_unlock(&ls->ls_rsbtbl[i].lock);
	234	}
	235	ri->entry = i;
	236
	237	if (ri->entry >= ls->ls_rsbtbl_size)
	238	return 1;
	239	} else {
916297aa	240	struct dlm_rsb *old = ri->rsb;
e7fd4179 DT	241	i = ri->entry;
	242	read_lock(&ls->ls_rsbtbl[i].lock);
	243	ri->next = ri->next->next;
	244	if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
	245	/* End of list - move to next bucket */
	246	ri->next = NULL;
	247	ri->entry++;
	248	read_unlock(&ls->ls_rsbtbl[i].lock);
916297aa	249	dlm_put_rsb(old);
e7fd4179 DT	250	goto top;
e7fd4179 DT	251	}
916297aa	252	ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
292e539e	253	dlm_hold_rsb(ri->rsb);
e7fd4179	254	read_unlock(&ls->ls_rsbtbl[i].lock);
916297aa	255	dlm_put_rsb(old);
e7fd4179	256	}
e7fd4179 DT	257
	258	return 0;
	259	}
	260
	261	static void rsb_iter_free(struct rsb_iter *ri)
	262	{
	263	kfree(ri);
	264	}
	265
	266	static struct rsb_iter rsb_iter_init(struct dlm_ls ls)
	267	{
	268	struct rsb_iter *ri;
	269
9dd592d7	270	ri = kzalloc(sizeof *ri, GFP_KERNEL);
e7fd4179 DT	271	if (!ri)
	272	return NULL;
	273
	274	ri->ls = ls;
	275	ri->entry = 0;
	276	ri->next = NULL;
	277
	278	if (rsb_iter_next(ri)) {
	279	rsb_iter_free(ri);
	280	return NULL;
	281	}
	282
	283	return ri;
	284	}
	285
5de6319b	286	static void rsb_seq_start(struct seq_file file, loff_t *pos)
e7fd4179 DT	287	{
	288	struct rsb_iter *ri;
	289	loff_t n = *pos;
	290
	291	ri = rsb_iter_init(file->private);
	292	if (!ri)
	293	return NULL;
	294
	295	while (n--) {
	296	if (rsb_iter_next(ri)) {
	297	rsb_iter_free(ri);
	298	return NULL;
	299	}
	300	}
	301
	302	return ri;
	303	}
	304
5de6319b	305	static void rsb_seq_next(struct seq_file file, void iter_ptr, loff_t pos)
e7fd4179 DT	306	{
	307	struct rsb_iter *ri = iter_ptr;
	308
	309	(*pos)++;
	310
	311	if (rsb_iter_next(ri)) {
	312	rsb_iter_free(ri);
	313	return NULL;
	314	}
	315
	316	return ri;
	317	}
	318
5de6319b	319	static void rsb_seq_stop(struct seq_file file, void iter_ptr)
e7fd4179 DT	320	{
	321	/* nothing for now */
	322	}
	323
5de6319b	324	static int rsb_seq_show(struct seq_file file, void iter_ptr)
e7fd4179 DT	325	{
	326	struct rsb_iter *ri = iter_ptr;
	327
9dd592d7 DT	328	if (ri->master) {
	329	if (ri->header) {
	330	seq_printf(file, "id nodeid remid pid xid flags sts "
	331	"grmode rqmode time_ms len name\n");
	332	ri->header = 0;
	333	}
	334	if (is_master(ri->rsb))
	335	print_master_resource(ri->rsb, file);
	336	} else {
	337	print_resource(ri->rsb, file);
	338	}
e7fd4179 DT	339
	340	return 0;
	341	}
	342
5de6319b DT	343	static struct seq_operations rsb_seq_ops = {
	344	.start = rsb_seq_start,
	345	.next = rsb_seq_next,
	346	.stop = rsb_seq_stop,
	347	.show = rsb_seq_show,
e7fd4179 DT	348	};
e7fd4179 DT	349
5de6319b	350	static int rsb_open(struct inode inode, struct file file)
e7fd4179 DT	351	{
	352	struct seq_file *seq;
	353	int ret;
	354
20abf975	355	ret = seq_open(file, &rsb_seq_ops);
e7fd4179 DT	356	if (ret)
	357	return ret;
	358
	359	seq = file->private_data;
bba9dfd8	360	seq->private = inode->i_private;
e7fd4179 DT	361
	362	return 0;
	363	}
	364
00977a59	365	static const struct file_operations rsb_fops = {
e7fd4179	366	.owner = THIS_MODULE,
5de6319b	367	.open = rsb_open,
e7fd4179 DT	368	.read = seq_read,
	369	.llseek = seq_lseek,
	370	.release = seq_release
	371	};
	372
9dd592d7 DT	373	/*
	374	* Dump master lock state
	375	*/
	376
	377	static struct rsb_iter master_iter_init(struct dlm_ls ls, loff_t *pos)
	378	{
	379	struct rsb_iter *ri;
	380
	381	ri = kzalloc(sizeof *ri, GFP_KERNEL);
	382	if (!ri)
	383	return NULL;
	384
	385	ri->ls = ls;
	386	ri->entry = 0;
	387	ri->next = NULL;
	388	ri->master = 1;
	389
	390	if (*pos == 0)
	391	ri->header = 1;
	392
	393	if (rsb_iter_next(ri)) {
	394	rsb_iter_free(ri);
	395	return NULL;
	396	}
	397
	398	return ri;
	399	}
	400
	401	static void master_seq_start(struct seq_file file, loff_t *pos)
	402	{
	403	struct rsb_iter *ri;
	404	loff_t n = *pos;
	405
	406	ri = master_iter_init(file->private, pos);
	407	if (!ri)
	408	return NULL;
	409
	410	while (n--) {
	411	if (rsb_iter_next(ri)) {
	412	rsb_iter_free(ri);
	413	return NULL;
	414	}
	415	}
	416
	417	return ri;
	418	}
	419
	420	static struct seq_operations master_seq_ops = {
	421	.start = master_seq_start,
	422	.next = rsb_seq_next,
	423	.stop = rsb_seq_stop,
	424	.show = rsb_seq_show,
	425	};
	426
	427	static int master_open(struct inode inode, struct file file)
	428	{
	429	struct seq_file *seq;
	430	int ret;
	431
	432	ret = seq_open(file, &master_seq_ops);
	433	if (ret)
	434	return ret;
	435
	436	seq = file->private_data;
437	seq->private = inode->i_private;
438
439	return 0;
440	}
441
442	static const struct file_operations master_fops = {
443	.owner = THIS_MODULE,
444	.open = master_open,
445	.read = seq_read,
446	.llseek = seq_lseek,
447	.release = seq_release
448	};
449
5de6319b DT	450	/*
	451	* dump lkb's on the ls_waiters list
	452	*/
	453
	454	static int waiters_open(struct inode inode, struct file file)
	455	{
bba9dfd8	456	file->private_data = inode->i_private;
5de6319b DT	457	return 0;
	458	}
	459
	460	static ssize_t waiters_read(struct file file, char __user userbuf,
	461	size_t count, loff_t *ppos)
	462	{
	463	struct dlm_ls *ls = file->private_data;
	464	struct dlm_lkb *lkb;
06442440	465	size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
5de6319b DT	466
	467	mutex_lock(&debug_buf_lock);
	468	mutex_lock(&ls->ls_waiters_mutex);
	469	memset(debug_buf, 0, sizeof(debug_buf));
	470
	471	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
06442440 DT	472	ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
	473	lkb->lkb_id, lkb->lkb_wait_type,
	474	lkb->lkb_nodeid, lkb->lkb_resource->res_name);
	475	if (ret >= len - pos)
	476	break;
	477	pos += ret;
5de6319b DT	478	}
	479	mutex_unlock(&ls->ls_waiters_mutex);
	480
	481	rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
	482	mutex_unlock(&debug_buf_lock);
	483	return rv;
	484	}
	485
00977a59	486	static const struct file_operations waiters_fops = {
5de6319b DT	487	.owner = THIS_MODULE,
	488	.open = waiters_open,
	489	.read = waiters_read
	490	};
	491
e7fd4179 DT	492	int dlm_create_debug_file(struct dlm_ls *ls)
e7fd4179 DT	493	{
5de6319b DT	494	char name[DLM_LOCKSPACE_LEN+8];
	495
	496	ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
	497	S_IFREG \| S_IRUGO,
	498	dlm_root,
	499	ls,
	500	&rsb_fops);
20abf975	501	if (!ls->ls_debug_rsb_dentry)
5de6319b DT	502	return -ENOMEM;
	503
	504	memset(name, 0, sizeof(name));
	505	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
	506
	507	ls->ls_debug_waiters_dentry = debugfs_create_file(name,
	508	S_IFREG \| S_IRUGO,
	509	dlm_root,
	510	ls,
	511	&waiters_fops);
	512	if (!ls->ls_debug_waiters_dentry) {
	513	debugfs_remove(ls->ls_debug_rsb_dentry);
	514	return -ENOMEM;
	515	}
	516
9dd592d7 DT	517	memset(name, 0, sizeof(name));
	518	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_master", ls->ls_name);
	519
	520	ls->ls_debug_master_dentry = debugfs_create_file(name,
	521	S_IFREG \| S_IRUGO,
	522	dlm_root,
	523	ls,
	524	&master_fops);
	525	if (!ls->ls_debug_master_dentry) {
	526	debugfs_remove(ls->ls_debug_waiters_dentry);
	527	debugfs_remove(ls->ls_debug_rsb_dentry);
	528	return -ENOMEM;
	529	}
	530
5de6319b	531	return 0;
e7fd4179 DT	532	}
	533
	534	void dlm_delete_debug_file(struct dlm_ls *ls)
	535	{
5de6319b DT	536	if (ls->ls_debug_rsb_dentry)
	537	debugfs_remove(ls->ls_debug_rsb_dentry);
	538	if (ls->ls_debug_waiters_dentry)
	539	debugfs_remove(ls->ls_debug_waiters_dentry);
9dd592d7 DT	540	if (ls->ls_debug_master_dentry)
9dd592d7 DT	541	debugfs_remove(ls->ls_debug_master_dentry);
e7fd4179 DT	542	}
	543
	544	int dlm_register_debugfs(void)
	545	{
5de6319b	546	mutex_init(&debug_buf_lock);
e7fd4179 DT	547	dlm_root = debugfs_create_dir("dlm", NULL);
	548	return dlm_root ? 0 : -ENOMEM;
	549	}
	550
	551	void dlm_unregister_debugfs(void)
	552	{
	553	debugfs_remove(dlm_root);
	554	}
	555