[deliverable/linux.git] / fs / gfs2 / locking / dlm / plock.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 version 2.
 */

#include <linux/miscdevice.h>
#include <linux/lock_dlm_plock.h>

#include "lock_dlm.h"


static spinlock_t ops_lock;
static struct list_head send_list;
static struct list_head recv_list;
static wait_queue_head_t send_wq;
static wait_queue_head_t recv_wq;

struct plock_op {
	struct list_head list;
	int done;
	struct gdlm_plock_info info;
};

static inline void set_version(struct gdlm_plock_info *info)
{
	info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
	info->version[1] = GDLM_PLOCK_VERSION_MINOR;
	info->version[2] = GDLM_PLOCK_VERSION_PATCH;
}

static int check_version(struct gdlm_plock_info *info)
{
	if ((GDLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
	    (GDLM_PLOCK_VERSION_MINOR < info->version[1])) {
		log_error("plock device version mismatch: "
			  "kernel (%u.%u.%u), user (%u.%u.%u)",
			  GDLM_PLOCK_VERSION_MAJOR,
			  GDLM_PLOCK_VERSION_MINOR,
			  GDLM_PLOCK_VERSION_PATCH,
			  info->version[0],
			  info->version[1],
			  info->version[2]);
		return -EINVAL;
	}
	return 0;
}

static void send_op(struct plock_op *op)
{
	set_version(&op->info);
	INIT_LIST_HEAD(&op->list);
	spin_lock(&ops_lock);
	list_add_tail(&op->list, &send_list);
	spin_unlock(&ops_lock);
	wake_up(&send_wq);
}

int gdlm_plock(void *lockspace, struct lm_lockname *name,
	       struct file *file, int cmd, struct file_lock *fl)
{
	struct gdlm_ls *ls = lockspace;
	struct plock_op *op;
	int rv;

	op = kzalloc(sizeof(*op), GFP_KERNEL);
	if (!op)
		return -ENOMEM;

	op->info.optype		= GDLM_PLOCK_OP_LOCK;
	op->info.pid		= fl->fl_pid;
	op->info.ex		= (fl->fl_type == F_WRLCK);
	op->info.wait		= IS_SETLKW(cmd);
	op->info.fsid		= ls->id;
	op->info.number		= name->ln_number;
	op->info.start		= fl->fl_start;
	op->info.end		= fl->fl_end;
	op->info.owner		= (__u64)(long) fl->fl_owner;

	send_op(op);
	wait_event(recv_wq, (op->done != 0));

	spin_lock(&ops_lock);
	if (!list_empty(&op->list)) {
		printk(KERN_INFO "plock op on list\n");
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	rv = op->info.rv;

	if (!rv) {
		if (posix_lock_file_wait(file, fl) < 0)
			log_error("gdlm_plock: vfs lock error %x,%llx",
				  name->ln_type,
				  (unsigned long long)name->ln_number);
	}

	kfree(op);
	return rv;
}

int gdlm_punlock(void *lockspace, struct lm_lockname *name,
		 struct file *file, struct file_lock *fl)
{
	struct gdlm_ls *ls = lockspace;
	struct plock_op *op;
	int rv;

	op = kzalloc(sizeof(*op), GFP_KERNEL);
	if (!op)
		return -ENOMEM;

	if (posix_lock_file_wait(file, fl) < 0)
		log_error("gdlm_punlock: vfs unlock error %x,%llx",
			  name->ln_type, (unsigned long long)name->ln_number);

	op->info.optype		= GDLM_PLOCK_OP_UNLOCK;
	op->info.pid		= fl->fl_pid;
	op->info.fsid		= ls->id;
	op->info.number		= name->ln_number;
	op->info.start		= fl->fl_start;
	op->info.end		= fl->fl_end;
	op->info.owner		= (__u64)(long) fl->fl_owner;

	send_op(op);
	wait_event(recv_wq, (op->done != 0));

	spin_lock(&ops_lock);
	if (!list_empty(&op->list)) {
		printk(KERN_INFO "punlock op on list\n");
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	rv = op->info.rv;

	kfree(op);
	return rv;
}

int gdlm_plock_get(void *lockspace, struct lm_lockname *name,
		   struct file *file, struct file_lock *fl)
{
	struct gdlm_ls *ls = lockspace;
	struct plock_op *op;
	int rv;

	op = kzalloc(sizeof(*op), GFP_KERNEL);
	if (!op)
		return -ENOMEM;

	op->info.optype		= GDLM_PLOCK_OP_GET;
	op->info.pid		= fl->fl_pid;
	op->info.ex		= (fl->fl_type == F_WRLCK);
	op->info.fsid		= ls->id;
	op->info.number		= name->ln_number;
	op->info.start		= fl->fl_start;
	op->info.end		= fl->fl_end;

	send_op(op);
	wait_event(recv_wq, (op->done != 0));

	spin_lock(&ops_lock);
	if (!list_empty(&op->list)) {
		printk(KERN_INFO "plock_get op on list\n");
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	rv = op->info.rv;

	if (rv == 0)
		fl->fl_type = F_UNLCK;
	else if (rv > 0) {
		fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
		fl->fl_pid = op->info.pid;
		fl->fl_start = op->info.start;
		fl->fl_end = op->info.end;
	}

	kfree(op);
	return rv;
}

/* a read copies out one plock request from the send list */
static ssize_t dev_read(struct file *file, char __user *u, size_t count,
			loff_t *ppos)
{
	struct gdlm_plock_info info;
	struct plock_op *op = NULL;

	if (count < sizeof(info))
		return -EINVAL;

	spin_lock(&ops_lock);
	if (!list_empty(&send_list)) {
		op = list_entry(send_list.next, struct plock_op, list);
		list_move(&op->list, &recv_list);
		memcpy(&info, &op->info, sizeof(info));
	}
	spin_unlock(&ops_lock);

	if (!op)
		return -EAGAIN;

	if (copy_to_user(u, &info, sizeof(info)))
		return -EFAULT;
	return sizeof(info);
}

/* a write copies in one plock result that should match a plock_op
   on the recv list */
static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
			 loff_t *ppos)
{
	struct gdlm_plock_info info;
	struct plock_op *op;
	int found = 0;

	if (count != sizeof(info))
		return -EINVAL;

	if (copy_from_user(&info, u, sizeof(info)))
		return -EFAULT;

	if (check_version(&info))
		return -EINVAL;

	spin_lock(&ops_lock);
	list_for_each_entry(op, &recv_list, list) {
		if (op->info.fsid == info.fsid && op->info.number == info.number &&
		    op->info.owner == info.owner) {
			list_del_init(&op->list);
			found = 1;
			op->done = 1;
			memcpy(&op->info, &info, sizeof(info));
			break;
		}
	}
	spin_unlock(&ops_lock);

	if (found)
		wake_up(&recv_wq);
	else
		printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,
			(unsigned long long)info.number);
	return count;
}

static unsigned int dev_poll(struct file *file, poll_table *wait)
{
	poll_wait(file, &send_wq, wait);

	spin_lock(&ops_lock);
	if (!list_empty(&send_list)) {
		spin_unlock(&ops_lock);
		return POLLIN | POLLRDNORM;
	}
	spin_unlock(&ops_lock);
	return 0;
}

static struct file_operations dev_fops = {
	.read    = dev_read,
	.write   = dev_write,
	.poll    = dev_poll,
	.owner   = THIS_MODULE
};

static struct miscdevice plock_dev_misc = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = GDLM_PLOCK_MISC_NAME,
	.fops = &dev_fops
};

int gdlm_plock_init(void)
{
	int rv;

	spin_lock_init(&ops_lock);
	INIT_LIST_HEAD(&send_list);
	INIT_LIST_HEAD(&recv_list);
	init_waitqueue_head(&send_wq);
	init_waitqueue_head(&recv_wq);

	rv = misc_register(&plock_dev_misc);
	if (rv)
		printk(KERN_INFO "gdlm_plock_init: misc_register failed %d",
		       rv);
	return rv;
}

void gdlm_plock_exit(void)
{
	if (misc_deregister(&plock_dev_misc) < 0)
		printk(KERN_INFO "gdlm_plock_exit: misc_deregister failed");
}
Commit	Line	Data
869d81df DT	1	/*
	2	* Copyright (C) 2005 Red Hat, Inc. All rights reserved.
	3	*
	4	* This copyrighted material is made available to anyone wishing to use,
	5	* modify, copy, or redistribute it subject to the terms and conditions
e9fc2aa0	6	* of the GNU General Public License version 2.
869d81df DT	7	*/
	8
	9	#include <linux/miscdevice.h>
	10	#include <linux/lock_dlm_plock.h>
	11
	12	#include "lock_dlm.h"
	13
	14
	15	static spinlock_t ops_lock;
	16	static struct list_head send_list;
	17	static struct list_head recv_list;
	18	static wait_queue_head_t send_wq;
	19	static wait_queue_head_t recv_wq;
	20
	21	struct plock_op {
	22	struct list_head list;
	23	int done;
	24	struct gdlm_plock_info info;
	25	};
	26
	27	static inline void set_version(struct gdlm_plock_info *info)
	28	{
	29	info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
	30	info->version[1] = GDLM_PLOCK_VERSION_MINOR;
	31	info->version[2] = GDLM_PLOCK_VERSION_PATCH;
	32	}
	33
	34	static int check_version(struct gdlm_plock_info *info)
	35	{
	36	if ((GDLM_PLOCK_VERSION_MAJOR != info->version[0]) \|\|
	37	(GDLM_PLOCK_VERSION_MINOR < info->version[1])) {
	38	log_error("plock device version mismatch: "
	39	"kernel (%u.%u.%u), user (%u.%u.%u)",
	40	GDLM_PLOCK_VERSION_MAJOR,
	41	GDLM_PLOCK_VERSION_MINOR,
	42	GDLM_PLOCK_VERSION_PATCH,
	43	info->version[0],
	44	info->version[1],
	45	info->version[2]);
	46	return -EINVAL;
	47	}
	48	return 0;
	49	}
	50
	51	static void send_op(struct plock_op *op)
	52	{
	53	set_version(&op->info);
	54	INIT_LIST_HEAD(&op->list);
	55	spin_lock(&ops_lock);
	56	list_add_tail(&op->list, &send_list);
	57	spin_unlock(&ops_lock);
	58	wake_up(&send_wq);
	59	}
	60
9b47c11d	61	int gdlm_plock(void lockspace, struct lm_lockname name,
869d81df DT	62	struct file file, int cmd, struct file_lock fl)
869d81df DT	63	{
9b47c11d	64	struct gdlm_ls *ls = lockspace;
869d81df DT	65	struct plock_op *op;
	66	int rv;
	67
	68	op = kzalloc(sizeof(*op), GFP_KERNEL);
	69	if (!op)
	70	return -ENOMEM;
	71
	72	op->info.optype = GDLM_PLOCK_OP_LOCK;
3a2a9c96	73	op->info.pid = fl->fl_pid;
869d81df DT	74	op->info.ex = (fl->fl_type == F_WRLCK);
	75	op->info.wait = IS_SETLKW(cmd);
	76	op->info.fsid = ls->id;
	77	op->info.number = name->ln_number;
	78	op->info.start = fl->fl_start;
	79	op->info.end = fl->fl_end;
de9b75d3	80	op->info.owner = (__u64)(long) fl->fl_owner;
869d81df DT	81
	82	send_op(op);
	83	wait_event(recv_wq, (op->done != 0));
	84
	85	spin_lock(&ops_lock);
	86	if (!list_empty(&op->list)) {
d92a8d48	87	printk(KERN_INFO "plock op on list\n");
869d81df DT	88	list_del(&op->list);
	89	}
	90	spin_unlock(&ops_lock);
	91
	92	rv = op->info.rv;
	93
	94	if (!rv) {
	95	if (posix_lock_file_wait(file, fl) < 0)
	96	log_error("gdlm_plock: vfs lock error %x,%llx",
9229f013 DT	97	name->ln_type,
9229f013 DT	98	(unsigned long long)name->ln_number);
869d81df DT	99	}
	100
	101	kfree(op);
	102	return rv;
	103	}
	104
9b47c11d	105	int gdlm_punlock(void lockspace, struct lm_lockname name,
869d81df DT	106	struct file file, struct file_lock fl)
869d81df DT	107	{
9b47c11d	108	struct gdlm_ls *ls = lockspace;
869d81df DT	109	struct plock_op *op;
	110	int rv;
	111
	112	op = kzalloc(sizeof(*op), GFP_KERNEL);
	113	if (!op)
	114	return -ENOMEM;
	115
	116	if (posix_lock_file_wait(file, fl) < 0)
	117	log_error("gdlm_punlock: vfs unlock error %x,%llx",
9229f013	118	name->ln_type, (unsigned long long)name->ln_number);
869d81df DT	119
869d81df DT	120	op->info.optype = GDLM_PLOCK_OP_UNLOCK;
3a2a9c96	121	op->info.pid = fl->fl_pid;
869d81df DT	122	op->info.fsid = ls->id;
	123	op->info.number = name->ln_number;
	124	op->info.start = fl->fl_start;
	125	op->info.end = fl->fl_end;
de9b75d3	126	op->info.owner = (__u64)(long) fl->fl_owner;
869d81df DT	127
	128	send_op(op);
	129	wait_event(recv_wq, (op->done != 0));
	130
	131	spin_lock(&ops_lock);
	132	if (!list_empty(&op->list)) {
d92a8d48	133	printk(KERN_INFO "punlock op on list\n");
869d81df DT	134	list_del(&op->list);
	135	}
	136	spin_unlock(&ops_lock);
	137
	138	rv = op->info.rv;
	139
	140	kfree(op);
	141	return rv;
	142	}
	143
9b47c11d	144	int gdlm_plock_get(void lockspace, struct lm_lockname name,
869d81df DT	145	struct file file, struct file_lock fl)
869d81df DT	146	{
9b47c11d	147	struct gdlm_ls *ls = lockspace;
869d81df DT	148	struct plock_op *op;
	149	int rv;
	150
	151	op = kzalloc(sizeof(*op), GFP_KERNEL);
	152	if (!op)
	153	return -ENOMEM;
	154
	155	op->info.optype = GDLM_PLOCK_OP_GET;
3a2a9c96	156	op->info.pid = fl->fl_pid;
869d81df DT	157	op->info.ex = (fl->fl_type == F_WRLCK);
	158	op->info.fsid = ls->id;
	159	op->info.number = name->ln_number;
	160	op->info.start = fl->fl_start;
	161	op->info.end = fl->fl_end;
	162
	163	send_op(op);
	164	wait_event(recv_wq, (op->done != 0));
	165
	166	spin_lock(&ops_lock);
	167	if (!list_empty(&op->list)) {
d92a8d48	168	printk(KERN_INFO "plock_get op on list\n");
869d81df DT	169	list_del(&op->list);
	170	}
	171	spin_unlock(&ops_lock);
	172
	173	rv = op->info.rv;
	174
	175	if (rv == 0)
	176	fl->fl_type = F_UNLCK;
	177	else if (rv > 0) {
	178	fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
	179	fl->fl_pid = op->info.pid;
	180	fl->fl_start = op->info.start;
	181	fl->fl_end = op->info.end;
	182	}
	183
	184	kfree(op);
	185	return rv;
	186	}
	187
	188	/* a read copies out one plock request from the send list */
	189	static ssize_t dev_read(struct file file, char __user u, size_t count,
	190	loff_t *ppos)
	191	{
	192	struct gdlm_plock_info info;
	193	struct plock_op *op = NULL;
	194
	195	if (count < sizeof(info))
	196	return -EINVAL;
	197
	198	spin_lock(&ops_lock);
	199	if (!list_empty(&send_list)) {
	200	op = list_entry(send_list.next, struct plock_op, list);
	201	list_move(&op->list, &recv_list);
	202	memcpy(&info, &op->info, sizeof(info));
	203	}
	204	spin_unlock(&ops_lock);
	205
	206	if (!op)
	207	return -EAGAIN;
	208
	209	if (copy_to_user(u, &info, sizeof(info)))
	210	return -EFAULT;
	211	return sizeof(info);
	212	}
	213
	214	/* a write copies in one plock result that should match a plock_op
	215	on the recv list */
	216	static ssize_t dev_write(struct file file, const char __user u, size_t count,
	217	loff_t *ppos)
	218	{
	219	struct gdlm_plock_info info;
	220	struct plock_op *op;
	221	int found = 0;
	222
	223	if (count != sizeof(info))
	224	return -EINVAL;
	225
	226	if (copy_from_user(&info, u, sizeof(info)))
	227	return -EFAULT;
	228
	229	if (check_version(&info))
	230	return -EINVAL;
	231
	232	spin_lock(&ops_lock);
233	list_for_each_entry(op, &recv_list, list) {
9b47c11d	234	if (op->info.fsid == info.fsid && op->info.number == info.number &&
08eac93a	235	op->info.owner == info.owner) {
869d81df DT	236	list_del_init(&op->list);
	237	found = 1;
	238	op->done = 1;
	239	memcpy(&op->info, &info, sizeof(info));
	240	break;
	241	}
	242	}
	243	spin_unlock(&ops_lock);
	244
	245	if (found)
	246	wake_up(&recv_wq);
	247	else
d92a8d48	248	printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,
9229f013	249	(unsigned long long)info.number);
869d81df DT	250	return count;
	251	}
	252
	253	static unsigned int dev_poll(struct file file, poll_table wait)
	254	{
	255	poll_wait(file, &send_wq, wait);
	256
	257	spin_lock(&ops_lock);
	258	if (!list_empty(&send_list)) {
	259	spin_unlock(&ops_lock);
	260	return POLLIN \| POLLRDNORM;
	261	}
	262	spin_unlock(&ops_lock);
	263	return 0;
	264	}
	265
	266	static struct file_operations dev_fops = {
	267	.read = dev_read,
	268	.write = dev_write,
	269	.poll = dev_poll,
	270	.owner = THIS_MODULE
	271	};
	272
	273	static struct miscdevice plock_dev_misc = {
	274	.minor = MISC_DYNAMIC_MINOR,
	275	.name = GDLM_PLOCK_MISC_NAME,
	276	.fops = &dev_fops
	277	};
	278
	279	int gdlm_plock_init(void)
	280	{
	281	int rv;
	282
	283	spin_lock_init(&ops_lock);
	284	INIT_LIST_HEAD(&send_list);
	285	INIT_LIST_HEAD(&recv_list);
	286	init_waitqueue_head(&send_wq);
	287	init_waitqueue_head(&recv_wq);
	288
	289	rv = misc_register(&plock_dev_misc);
	290	if (rv)
d92a8d48 SW	291	printk(KERN_INFO "gdlm_plock_init: misc_register failed %d",
d92a8d48 SW	292	rv);
869d81df DT	293	return rv;
	294	}
	295
	296	void gdlm_plock_exit(void)
	297	{
	298	if (misc_deregister(&plock_dev_misc) < 0)
d92a8d48	299	printk(KERN_INFO "gdlm_plock_exit: misc_deregister failed");
869d81df DT	300	}
869d81df DT	301