[net-next-2.6.git] / fs / dlm / plock.c

/*
 * Copyright (C) 2005-2008 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/fs.h>
#include <linux/miscdevice.h>
#include <linux/poll.h>
#include <linux/dlm.h>
#include <linux/dlm_plock.h>

#include "dlm_internal.h"
#include "lockspace.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 dlm_plock_info info;
};

struct plock_xop {
	struct plock_op xop;
	void *callback;
	void *fl;
	void *file;
	struct file_lock flc;
};


static inline void set_version(struct dlm_plock_info *info)
{
	info->version[0] = DLM_PLOCK_VERSION_MAJOR;
	info->version[1] = DLM_PLOCK_VERSION_MINOR;
	info->version[2] = DLM_PLOCK_VERSION_PATCH;
}

static int check_version(struct dlm_plock_info *info)
{
	if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
	    (DLM_PLOCK_VERSION_MINOR < info->version[1])) {
		log_print("plock device version mismatch: "
			  "kernel (%u.%u.%u), user (%u.%u.%u)",
			  DLM_PLOCK_VERSION_MAJOR,
			  DLM_PLOCK_VERSION_MINOR,
			  DLM_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 dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
		   int cmd, struct file_lock *fl)
{
	struct dlm_ls *ls;
	struct plock_op *op;
	struct plock_xop *xop;
	int rv;

	ls = dlm_find_lockspace_local(lockspace);
	if (!ls)
		return -EINVAL;

	xop = kzalloc(sizeof(*xop), GFP_KERNEL);
	if (!xop) {
		rv = -ENOMEM;
		goto out;
	}

	op = &xop->xop;
	op->info.optype		= DLM_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->ls_global_id;
	op->info.number		= number;
	op->info.start		= fl->fl_start;
	op->info.end		= fl->fl_end;
	if (fl->fl_lmops && fl->fl_lmops->fl_grant) {
		/* fl_owner is lockd which doesn't distinguish
		   processes on the nfs client */
		op->info.owner	= (__u64) fl->fl_pid;
		xop->callback	= fl->fl_lmops->fl_grant;
		locks_init_lock(&xop->flc);
		locks_copy_lock(&xop->flc, fl);
		xop->fl		= fl;
		xop->file	= file;
	} else {
		op->info.owner	= (__u64)(long) fl->fl_owner;
		xop->callback	= NULL;
	}

	send_op(op);

	if (xop->callback == NULL)
		wait_event(recv_wq, (op->done != 0));
	else {
		rv = -EINPROGRESS;
		goto out;
	}

	spin_lock(&ops_lock);
	if (!list_empty(&op->list)) {
		log_error(ls, "dlm_posix_lock: op on list %llx",
			  (unsigned long long)number);
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	rv = op->info.rv;

	if (!rv) {
		if (posix_lock_file_wait(file, fl) < 0)
			log_error(ls, "dlm_posix_lock: vfs lock error %llx",
				  (unsigned long long)number);
	}

	kfree(xop);
out:
	dlm_put_lockspace(ls);
	return rv;
}
EXPORT_SYMBOL_GPL(dlm_posix_lock);

/* Returns failure iff a succesful lock operation should be canceled */
static int dlm_plock_callback(struct plock_op *op)
{
	struct file *file;
	struct file_lock *fl;
	struct file_lock *flc;
	int (*notify)(void *, void *, int) = NULL;
	struct plock_xop *xop = (struct plock_xop *)op;
	int rv = 0;

	spin_lock(&ops_lock);
	if (!list_empty(&op->list)) {
		log_print("dlm_plock_callback: op on list %llx",
			  (unsigned long long)op->info.number);
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	/* check if the following 2 are still valid or make a copy */
	file = xop->file;
	flc = &xop->flc;
	fl = xop->fl;
	notify = xop->callback;

	if (op->info.rv) {
		notify(flc, NULL, op->info.rv);
		goto out;
	}

	/* got fs lock; bookkeep locally as well: */
	flc->fl_flags &= ~FL_SLEEP;
	if (posix_lock_file(file, flc, NULL)) {
		/*
		 * This can only happen in the case of kmalloc() failure.
		 * The filesystem's own lock is the authoritative lock,
		 * so a failure to get the lock locally is not a disaster.
		 * As long as the fs cannot reliably cancel locks (especially
		 * in a low-memory situation), we're better off ignoring
		 * this failure than trying to recover.
		 */
		log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
			  (unsigned long long)op->info.number, file, fl);
	}

	rv = notify(flc, NULL, 0);
	if (rv) {
		/* XXX: We need to cancel the fs lock here: */
		log_print("dlm_plock_callback: lock granted after lock request "
			  "failed; dangling lock!\n");
		goto out;
	}

out:
	kfree(xop);
	return rv;
}

int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
		     struct file_lock *fl)
{
	struct dlm_ls *ls;
	struct plock_op *op;
	int rv;

	ls = dlm_find_lockspace_local(lockspace);
	if (!ls)
		return -EINVAL;

	op = kzalloc(sizeof(*op), GFP_KERNEL);
	if (!op) {
		rv = -ENOMEM;
		goto out;
	}

	if (posix_lock_file_wait(file, fl) < 0)
		log_error(ls, "dlm_posix_unlock: vfs unlock error %llx",
			  (unsigned long long)number);

	op->info.optype		= DLM_PLOCK_OP_UNLOCK;
	op->info.pid		= fl->fl_pid;
	op->info.fsid		= ls->ls_global_id;
	op->info.number		= number;
	op->info.start		= fl->fl_start;
	op->info.end		= fl->fl_end;
	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
		op->info.owner	= (__u64) fl->fl_pid;
	else
		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)) {
		log_error(ls, "dlm_posix_unlock: op on list %llx",
			  (unsigned long long)number);
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	rv = op->info.rv;

	if (rv == -ENOENT)
		rv = 0;

	kfree(op);
out:
	dlm_put_lockspace(ls);
	return rv;
}
EXPORT_SYMBOL_GPL(dlm_posix_unlock);

int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
		  struct file_lock *fl)
{
	struct dlm_ls *ls;
	struct plock_op *op;
	int rv;

	ls = dlm_find_lockspace_local(lockspace);
	if (!ls)
		return -EINVAL;

	op = kzalloc(sizeof(*op), GFP_KERNEL);
	if (!op) {
		rv = -ENOMEM;
		goto out;
	}

	op->info.optype		= DLM_PLOCK_OP_GET;
	op->info.pid		= fl->fl_pid;
	op->info.ex		= (fl->fl_type == F_WRLCK);
	op->info.fsid		= ls->ls_global_id;
	op->info.number		= number;
	op->info.start		= fl->fl_start;
	op->info.end		= fl->fl_end;
	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
		op->info.owner	= (__u64) fl->fl_pid;
	else
		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)) {
		log_error(ls, "dlm_posix_get: op on list %llx",
			  (unsigned long long)number);
		list_del(&op->list);
	}
	spin_unlock(&ops_lock);

	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
	   -ENOENT if there are no locks on the file */

	rv = op->info.rv;

	fl->fl_type = F_UNLCK;
	if (rv == -ENOENT)
		rv = 0;
	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;
		rv = 0;
	}

	kfree(op);
out:
	dlm_put_lockspace(ls);
	return rv;
}
EXPORT_SYMBOL_GPL(dlm_posix_get);

/* 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 dlm_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 dlm_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) {
		struct plock_xop *xop;
		xop = (struct plock_xop *)op;
		if (xop->callback)
			count = dlm_plock_callback(op);
		else
			wake_up(&recv_wq);
	} else
		log_print("dev_write no op %x %llx", info.fsid,
			  (unsigned long long)info.number);
	return count;
}

static unsigned int dev_poll(struct file *file, poll_table *wait)
{
	unsigned int mask = 0;

	poll_wait(file, &send_wq, wait);

	spin_lock(&ops_lock);
	if (!list_empty(&send_list))
		mask = POLLIN | POLLRDNORM;
	spin_unlock(&ops_lock);

	return mask;
}

static const 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 = DLM_PLOCK_MISC_NAME,
	.fops = &dev_fops
};

int dlm_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)
		log_print("dlm_plock_init: misc_register failed %d", rv);
	return rv;
}

void dlm_plock_exit(void)
{
	if (misc_deregister(&plock_dev_misc) < 0)
		log_print("dlm_plock_exit: misc_deregister failed");
}
Commit	Line	Data
869d81df	1	/*
2402211a	2	* Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
869d81df DT	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	*/
869d81df DT	8
2402211a	9	#include <linux/fs.h>
869d81df	10	#include <linux/miscdevice.h>
bd01f843	11	#include <linux/poll.h>
2402211a DT	12	#include <linux/dlm.h>
2402211a DT	13	#include <linux/dlm_plock.h>
869d81df	14
2402211a DT	15	#include "dlm_internal.h"
2402211a DT	16	#include "lockspace.h"
869d81df DT	17
	18	static spinlock_t ops_lock;
	19	static struct list_head send_list;
	20	static struct list_head recv_list;
	21	static wait_queue_head_t send_wq;
	22	static wait_queue_head_t recv_wq;
	23
	24	struct plock_op {
	25	struct list_head list;
	26	int done;
2402211a	27	struct dlm_plock_info info;
869d81df DT	28	};
869d81df DT	29
586759f0 ME	30	struct plock_xop {
	31	struct plock_op xop;
	32	void *callback;
	33	void *fl;
	34	void *file;
	35	struct file_lock flc;
	36	};
	37
	38
2402211a	39	static inline void set_version(struct dlm_plock_info *info)
869d81df	40	{
2402211a DT	41	info->version[0] = DLM_PLOCK_VERSION_MAJOR;
	42	info->version[1] = DLM_PLOCK_VERSION_MINOR;
	43	info->version[2] = DLM_PLOCK_VERSION_PATCH;
869d81df DT	44	}
869d81df DT	45
2402211a	46	static int check_version(struct dlm_plock_info *info)
869d81df	47	{
2402211a DT	48	if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) \|\|
	49	(DLM_PLOCK_VERSION_MINOR < info->version[1])) {
	50	log_print("plock device version mismatch: "
869d81df	51	"kernel (%u.%u.%u), user (%u.%u.%u)",
2402211a DT	52	DLM_PLOCK_VERSION_MAJOR,
	53	DLM_PLOCK_VERSION_MINOR,
	54	DLM_PLOCK_VERSION_PATCH,
869d81df DT	55	info->version[0],
	56	info->version[1],
	57	info->version[2]);
	58	return -EINVAL;
	59	}
	60	return 0;
	61	}
	62
	63	static void send_op(struct plock_op *op)
	64	{
	65	set_version(&op->info);
	66	INIT_LIST_HEAD(&op->list);
	67	spin_lock(&ops_lock);
	68	list_add_tail(&op->list, &send_list);
	69	spin_unlock(&ops_lock);
	70	wake_up(&send_wq);
	71	}
	72
2402211a DT	73	int dlm_posix_lock(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	74	int cmd, struct file_lock *fl)
869d81df	75	{
2402211a	76	struct dlm_ls *ls;
869d81df	77	struct plock_op *op;
586759f0	78	struct plock_xop *xop;
869d81df DT	79	int rv;
869d81df DT	80
2402211a DT	81	ls = dlm_find_lockspace_local(lockspace);
	82	if (!ls)
	83	return -EINVAL;
	84
586759f0	85	xop = kzalloc(sizeof(*xop), GFP_KERNEL);
2402211a DT	86	if (!xop) {
	87	rv = -ENOMEM;
	88	goto out;
	89	}
869d81df	90
586759f0	91	op = &xop->xop;
2402211a	92	op->info.optype = DLM_PLOCK_OP_LOCK;
3a2a9c96	93	op->info.pid = fl->fl_pid;
869d81df DT	94	op->info.ex = (fl->fl_type == F_WRLCK);
869d81df DT	95	op->info.wait = IS_SETLKW(cmd);
2402211a DT	96	op->info.fsid = ls->ls_global_id;
2402211a DT	97	op->info.number = number;
869d81df DT	98	op->info.start = fl->fl_start;
869d81df DT	99	op->info.end = fl->fl_end;
586759f0	100	if (fl->fl_lmops && fl->fl_lmops->fl_grant) {
2066b58b DT	101	/* fl_owner is lockd which doesn't distinguish
	102	processes on the nfs client */
	103	op->info.owner = (__u64) fl->fl_pid;
586759f0 ME	104	xop->callback = fl->fl_lmops->fl_grant;
	105	locks_init_lock(&xop->flc);
	106	locks_copy_lock(&xop->flc, fl);
	107	xop->fl = fl;
	108	xop->file = file;
2066b58b DT	109	} else {
2066b58b DT	110	op->info.owner = (__u64)(long) fl->fl_owner;
586759f0	111	xop->callback = NULL;
2066b58b	112	}
869d81df DT	113
869d81df DT	114	send_op(op);
586759f0 ME	115
	116	if (xop->callback == NULL)
	117	wait_event(recv_wq, (op->done != 0));
2402211a DT	118	else {
	119	rv = -EINPROGRESS;
	120	goto out;
	121	}
869d81df DT	122
	123	spin_lock(&ops_lock);
	124	if (!list_empty(&op->list)) {
2402211a DT	125	log_error(ls, "dlm_posix_lock: op on list %llx",
2402211a DT	126	(unsigned long long)number);
869d81df DT	127	list_del(&op->list);
	128	}
	129	spin_unlock(&ops_lock);
	130
	131	rv = op->info.rv;
	132
	133	if (!rv) {
	134	if (posix_lock_file_wait(file, fl) < 0)
2402211a DT	135	log_error(ls, "dlm_posix_lock: vfs lock error %llx",
2402211a DT	136	(unsigned long long)number);
869d81df DT	137	}
869d81df DT	138
586759f0	139	kfree(xop);
2402211a DT	140	out:
2402211a DT	141	dlm_put_lockspace(ls);
586759f0 ME	142	return rv;
586759f0 ME	143	}
2402211a	144	EXPORT_SYMBOL_GPL(dlm_posix_lock);
586759f0 ME	145
586759f0 ME	146	/* Returns failure iff a succesful lock operation should be canceled */
2402211a	147	static int dlm_plock_callback(struct plock_op *op)
586759f0 ME	148	{
	149	struct file *file;
	150	struct file_lock *fl;
	151	struct file_lock *flc;
	152	int (notify)(void , void *, int) = NULL;
	153	struct plock_xop xop = (struct plock_xop )op;
	154	int rv = 0;
	155
	156	spin_lock(&ops_lock);
	157	if (!list_empty(&op->list)) {
2402211a DT	158	log_print("dlm_plock_callback: op on list %llx",
2402211a DT	159	(unsigned long long)op->info.number);
586759f0 ME	160	list_del(&op->list);
	161	}
	162	spin_unlock(&ops_lock);
	163
	164	/* check if the following 2 are still valid or make a copy */
	165	file = xop->file;
	166	flc = &xop->flc;
	167	fl = xop->fl;
	168	notify = xop->callback;
	169
	170	if (op->info.rv) {
	171	notify(flc, NULL, op->info.rv);
	172	goto out;
	173	}
	174
	175	/* got fs lock; bookkeep locally as well: */
	176	flc->fl_flags &= ~FL_SLEEP;
	177	if (posix_lock_file(file, flc, NULL)) {
	178	/*
	179	* This can only happen in the case of kmalloc() failure.
	180	* The filesystem's own lock is the authoritative lock,
	181	* so a failure to get the lock locally is not a disaster.
2402211a	182	* As long as the fs cannot reliably cancel locks (especially
586759f0 ME	183	* in a low-memory situation), we're better off ignoring
	184	* this failure than trying to recover.
	185	*/
2402211a DT	186	log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
2402211a DT	187	(unsigned long long)op->info.number, file, fl);
586759f0 ME	188	}
	189
	190	rv = notify(flc, NULL, 0);
	191	if (rv) {
	192	/* XXX: We need to cancel the fs lock here: */
2402211a DT	193	log_print("dlm_plock_callback: lock granted after lock request "
2402211a DT	194	"failed; dangling lock!\n");
586759f0 ME	195	goto out;
	196	}
	197
	198	out:
	199	kfree(xop);
869d81df DT	200	return rv;
	201	}
	202
2402211a DT	203	int dlm_posix_unlock(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	204	struct file_lock *fl)
869d81df	205	{
2402211a	206	struct dlm_ls *ls;
869d81df DT	207	struct plock_op *op;
	208	int rv;
	209
2402211a DT	210	ls = dlm_find_lockspace_local(lockspace);
	211	if (!ls)
	212	return -EINVAL;
	213
869d81df	214	op = kzalloc(sizeof(*op), GFP_KERNEL);
2402211a DT	215	if (!op) {
	216	rv = -ENOMEM;
	217	goto out;
	218	}
869d81df DT	219
869d81df DT	220	if (posix_lock_file_wait(file, fl) < 0)
2402211a DT	221	log_error(ls, "dlm_posix_unlock: vfs unlock error %llx",
2402211a DT	222	(unsigned long long)number);
869d81df	223
2402211a	224	op->info.optype = DLM_PLOCK_OP_UNLOCK;
3a2a9c96	225	op->info.pid = fl->fl_pid;
2402211a DT	226	op->info.fsid = ls->ls_global_id;
2402211a DT	227	op->info.number = number;
869d81df DT	228	op->info.start = fl->fl_start;
869d81df DT	229	op->info.end = fl->fl_end;
2066b58b DT	230	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
	231	op->info.owner = (__u64) fl->fl_pid;
	232	else
	233	op->info.owner = (__u64)(long) fl->fl_owner;
869d81df DT	234
	235	send_op(op);
	236	wait_event(recv_wq, (op->done != 0));
	237
	238	spin_lock(&ops_lock);
	239	if (!list_empty(&op->list)) {
2402211a DT	240	log_error(ls, "dlm_posix_unlock: op on list %llx",
2402211a DT	241	(unsigned long long)number);
869d81df DT	242	list_del(&op->list);
	243	}
	244	spin_unlock(&ops_lock);
	245
	246	rv = op->info.rv;
	247
586759f0 ME	248	if (rv == -ENOENT)
	249	rv = 0;
	250
869d81df	251	kfree(op);
2402211a DT	252	out:
2402211a DT	253	dlm_put_lockspace(ls);
869d81df DT	254	return rv;
869d81df DT	255	}
2402211a	256	EXPORT_SYMBOL_GPL(dlm_posix_unlock);
869d81df	257
2402211a DT	258	int dlm_posix_get(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	259	struct file_lock *fl)
869d81df	260	{
2402211a	261	struct dlm_ls *ls;
869d81df DT	262	struct plock_op *op;
	263	int rv;
	264
2402211a DT	265	ls = dlm_find_lockspace_local(lockspace);
	266	if (!ls)
	267	return -EINVAL;
	268
869d81df	269	op = kzalloc(sizeof(*op), GFP_KERNEL);
2402211a DT	270	if (!op) {
	271	rv = -ENOMEM;
	272	goto out;
	273	}
869d81df	274
2402211a	275	op->info.optype = DLM_PLOCK_OP_GET;
3a2a9c96	276	op->info.pid = fl->fl_pid;
869d81df	277	op->info.ex = (fl->fl_type == F_WRLCK);
2402211a DT	278	op->info.fsid = ls->ls_global_id;
2402211a DT	279	op->info.number = number;
869d81df DT	280	op->info.start = fl->fl_start;
869d81df DT	281	op->info.end = fl->fl_end;
2066b58b DT	282	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
	283	op->info.owner = (__u64) fl->fl_pid;
	284	else
	285	op->info.owner = (__u64)(long) fl->fl_owner;
586759f0	286
869d81df DT	287	send_op(op);
	288	wait_event(recv_wq, (op->done != 0));
	289
	290	spin_lock(&ops_lock);
	291	if (!list_empty(&op->list)) {
2402211a DT	292	log_error(ls, "dlm_posix_get: op on list %llx",
2402211a DT	293	(unsigned long long)number);
869d81df DT	294	list_del(&op->list);
	295	}
	296	spin_unlock(&ops_lock);
	297
a7a2ff8a DT	298	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
	299	-ENOENT if there are no locks on the file */
	300
869d81df DT	301	rv = op->info.rv;
869d81df DT	302
586759f0 ME	303	fl->fl_type = F_UNLCK;
	304	if (rv == -ENOENT)
	305	rv = 0;
a7a2ff8a	306	else if (rv > 0) {
869d81df DT	307	fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
	308	fl->fl_pid = op->info.pid;
	309	fl->fl_start = op->info.start;
	310	fl->fl_end = op->info.end;
a7a2ff8a	311	rv = 0;
869d81df DT	312	}
	313
	314	kfree(op);
2402211a DT	315	out:
2402211a DT	316	dlm_put_lockspace(ls);
869d81df DT	317	return rv;
869d81df DT	318	}
2402211a	319	EXPORT_SYMBOL_GPL(dlm_posix_get);
869d81df DT	320
	321	/* a read copies out one plock request from the send list */
	322	static ssize_t dev_read(struct file file, char __user u, size_t count,
	323	loff_t *ppos)
	324	{
2402211a	325	struct dlm_plock_info info;
869d81df DT	326	struct plock_op *op = NULL;
	327
	328	if (count < sizeof(info))
	329	return -EINVAL;
	330
	331	spin_lock(&ops_lock);
	332	if (!list_empty(&send_list)) {
	333	op = list_entry(send_list.next, struct plock_op, list);
	334	list_move(&op->list, &recv_list);
	335	memcpy(&info, &op->info, sizeof(info));
	336	}
	337	spin_unlock(&ops_lock);
	338
	339	if (!op)
	340	return -EAGAIN;
	341
	342	if (copy_to_user(u, &info, sizeof(info)))
	343	return -EFAULT;
	344	return sizeof(info);
	345	}
	346
	347	/* a write copies in one plock result that should match a plock_op
	348	on the recv list */
	349	static ssize_t dev_write(struct file file, const char __user u, size_t count,
	350	loff_t *ppos)
	351	{
2402211a	352	struct dlm_plock_info info;
869d81df DT	353	struct plock_op *op;
	354	int found = 0;
	355
	356	if (count != sizeof(info))
	357	return -EINVAL;
	358
	359	if (copy_from_user(&info, u, sizeof(info)))
	360	return -EFAULT;
	361
	362	if (check_version(&info))
	363	return -EINVAL;
	364
	365	spin_lock(&ops_lock);
	366	list_for_each_entry(op, &recv_list, list) {
9b47c11d	367	if (op->info.fsid == info.fsid && op->info.number == info.number &&
08eac93a	368	op->info.owner == info.owner) {
869d81df DT	369	list_del_init(&op->list);
	370	found = 1;
	371	op->done = 1;
	372	memcpy(&op->info, &info, sizeof(info));
	373	break;
	374	}
	375	}
	376	spin_unlock(&ops_lock);
	377
586759f0 ME	378	if (found) {
	379	struct plock_xop *xop;
	380	xop = (struct plock_xop *)op;
	381	if (xop->callback)
2402211a	382	count = dlm_plock_callback(op);
586759f0 ME	383	else
	384	wake_up(&recv_wq);
	385	} else
2402211a DT	386	log_print("dev_write no op %x %llx", info.fsid,
2402211a DT	387	(unsigned long long)info.number);
869d81df DT	388	return count;
	389	}
	390
	391	static unsigned int dev_poll(struct file file, poll_table wait)
	392	{
cee23c79 DC	393	unsigned int mask = 0;
cee23c79 DC	394
869d81df DT	395	poll_wait(file, &send_wq, wait);
	396
	397	spin_lock(&ops_lock);
cee23c79 DC	398	if (!list_empty(&send_list))
cee23c79 DC	399	mask = POLLIN \| POLLRDNORM;
869d81df	400	spin_unlock(&ops_lock);
cee23c79 DC	401
cee23c79 DC	402	return mask;
869d81df DT	403	}
869d81df DT	404
00977a59	405	static const struct file_operations dev_fops = {
869d81df DT	406	.read = dev_read,
	407	.write = dev_write,
	408	.poll = dev_poll,
	409	.owner = THIS_MODULE
	410	};
	411
	412	static struct miscdevice plock_dev_misc = {
	413	.minor = MISC_DYNAMIC_MINOR,
2402211a	414	.name = DLM_PLOCK_MISC_NAME,
869d81df DT	415	.fops = &dev_fops
	416	};
	417
2402211a	418	int dlm_plock_init(void)
869d81df DT	419	{
	420	int rv;
	421
	422	spin_lock_init(&ops_lock);
	423	INIT_LIST_HEAD(&send_list);
	424	INIT_LIST_HEAD(&recv_list);
	425	init_waitqueue_head(&send_wq);
	426	init_waitqueue_head(&recv_wq);
	427
	428	rv = misc_register(&plock_dev_misc);
	429	if (rv)
2402211a	430	log_print("dlm_plock_init: misc_register failed %d", rv);
869d81df DT	431	return rv;
	432	}
	433
2402211a	434	void dlm_plock_exit(void)
869d81df DT	435	{
869d81df DT	436	if (misc_deregister(&plock_dev_misc) < 0)
2402211a	437	log_print("dlm_plock_exit: misc_deregister failed");
869d81df DT	438	}
869d81df DT	439