[linux.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 <linux/slab.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);
}

/* If a process was killed while waiting for the only plock on a file,
   locks_remove_posix will not see any lock on the file so it won't
   send an unlock-close to us to pass on to userspace to clean up the
   abandoned waiter.  So, we have to insert the unlock-close when the
   lock call is interrupted. */

static void do_unlock_close(struct dlm_ls *ls, u64 number,
			    struct file *file, struct file_lock *fl)
{
	struct plock_op *op;

	op = kzalloc(sizeof(*op), GFP_NOFS);
	if (!op)
		return;

	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		= 0;
	op->info.end		= OFFSET_MAX;
	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;

	op->info.flags |= DLM_PLOCK_FL_CLOSE;
	send_op(op);
}

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_NOFS);
	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) {
		rv = wait_event_killable(recv_wq, (op->done != 0));
		if (rv == -ERESTARTSYS) {
			log_debug(ls, "dlm_posix_lock: wait killed %llx",
				  (unsigned long long)number);
			spin_lock(&ops_lock);
			list_del(&op->list);
			spin_unlock(&ops_lock);
			kfree(xop);
			do_unlock_close(ls, number, file, fl);
			goto out;
		}
	} else {
		rv = FILE_LOCK_DEFERRED;
		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 successful 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(fl, 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(fl, 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_NOFS);
	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;

	if (fl->fl_flags & FL_CLOSE) {
		op->info.flags |= DLM_PLOCK_FL_CLOSE;
		send_op(op);
		rv = 0;
		goto out;
	}

	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_NOFS);
	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) {
		locks_init_lock(fl);
		fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
		fl->fl_flags = FL_POSIX;
		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);
		if (op->info.flags & DLM_PLOCK_FL_CLOSE)
			list_del(&op->list);
		else
			list_move(&op->list, &recv_list);
		memcpy(&info, &op->info, sizeof(info));
	}
	spin_unlock(&ops_lock);

	if (!op)
		return -EAGAIN;

	/* there is no need to get a reply from userspace for unlocks
	   that were generated by the vfs cleaning up for a close
	   (the process did not make an unlock call). */

	if (op->info.flags & DLM_PLOCK_FL_CLOSE)
		kfree(op);

	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, do_callback = 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) {
			struct plock_xop *xop = (struct plock_xop *)op;
			list_del_init(&op->list);
			memcpy(&op->info, &info, sizeof(info));
			if (xop->callback)
				do_callback = 1;
			else
				op->done = 1;
			found = 1;
			break;
		}
	}
	spin_unlock(&ops_lock);

	if (found) {
		if (do_callback)
			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,
	.llseek  = noop_llseek,
};

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>
5a0e3ad6	14	#include <linux/slab.h>
869d81df	15
2402211a DT	16	#include "dlm_internal.h"
2402211a DT	17	#include "lockspace.h"
869d81df DT	18
	19	static spinlock_t ops_lock;
	20	static struct list_head send_list;
	21	static struct list_head recv_list;
	22	static wait_queue_head_t send_wq;
	23	static wait_queue_head_t recv_wq;
	24
	25	struct plock_op {
	26	struct list_head list;
	27	int done;
2402211a	28	struct dlm_plock_info info;
869d81df DT	29	};
869d81df DT	30
586759f0 ME	31	struct plock_xop {
	32	struct plock_op xop;
	33	void *callback;
	34	void *fl;
	35	void *file;
	36	struct file_lock flc;
	37	};
	38
	39
2402211a	40	static inline void set_version(struct dlm_plock_info *info)
869d81df	41	{
2402211a DT	42	info->version[0] = DLM_PLOCK_VERSION_MAJOR;
	43	info->version[1] = DLM_PLOCK_VERSION_MINOR;
	44	info->version[2] = DLM_PLOCK_VERSION_PATCH;
869d81df DT	45	}
869d81df DT	46
2402211a	47	static int check_version(struct dlm_plock_info *info)
869d81df	48	{
2402211a DT	49	if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) \|\|
	50	(DLM_PLOCK_VERSION_MINOR < info->version[1])) {
	51	log_print("plock device version mismatch: "
869d81df	52	"kernel (%u.%u.%u), user (%u.%u.%u)",
2402211a DT	53	DLM_PLOCK_VERSION_MAJOR,
	54	DLM_PLOCK_VERSION_MINOR,
	55	DLM_PLOCK_VERSION_PATCH,
869d81df DT	56	info->version[0],
	57	info->version[1],
	58	info->version[2]);
	59	return -EINVAL;
	60	}
	61	return 0;
	62	}
	63
	64	static void send_op(struct plock_op *op)
	65	{
	66	set_version(&op->info);
	67	INIT_LIST_HEAD(&op->list);
	68	spin_lock(&ops_lock);
	69	list_add_tail(&op->list, &send_list);
	70	spin_unlock(&ops_lock);
	71	wake_up(&send_wq);
	72	}
	73
901025d2 DT	74	/* If a process was killed while waiting for the only plock on a file,
	75	locks_remove_posix will not see any lock on the file so it won't
	76	send an unlock-close to us to pass on to userspace to clean up the
	77	abandoned waiter. So, we have to insert the unlock-close when the
	78	lock call is interrupted. */
	79
	80	static void do_unlock_close(struct dlm_ls *ls, u64 number,
	81	struct file file, struct file_lock fl)
	82	{
	83	struct plock_op *op;
	84
	85	op = kzalloc(sizeof(*op), GFP_NOFS);
	86	if (!op)
	87	return;
	88
	89	op->info.optype = DLM_PLOCK_OP_UNLOCK;
	90	op->info.pid = fl->fl_pid;
	91	op->info.fsid = ls->ls_global_id;
	92	op->info.number = number;
	93	op->info.start = 0;
	94	op->info.end = OFFSET_MAX;
	95	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
	96	op->info.owner = (__u64) fl->fl_pid;
	97	else
	98	op->info.owner = (__u64)(long) fl->fl_owner;
	99
	100	op->info.flags \|= DLM_PLOCK_FL_CLOSE;
	101	send_op(op);
	102	}
	103
2402211a DT	104	int dlm_posix_lock(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	105	int cmd, struct file_lock *fl)
869d81df	106	{
2402211a	107	struct dlm_ls *ls;
869d81df	108	struct plock_op *op;
586759f0	109	struct plock_xop *xop;
869d81df DT	110	int rv;
869d81df DT	111
2402211a DT	112	ls = dlm_find_lockspace_local(lockspace);
	113	if (!ls)
	114	return -EINVAL;
	115
573c24c4	116	xop = kzalloc(sizeof(*xop), GFP_NOFS);
2402211a DT	117	if (!xop) {
	118	rv = -ENOMEM;
	119	goto out;
	120	}
869d81df	121
586759f0	122	op = &xop->xop;
2402211a	123	op->info.optype = DLM_PLOCK_OP_LOCK;
3a2a9c96	124	op->info.pid = fl->fl_pid;
869d81df DT	125	op->info.ex = (fl->fl_type == F_WRLCK);
869d81df DT	126	op->info.wait = IS_SETLKW(cmd);
2402211a DT	127	op->info.fsid = ls->ls_global_id;
2402211a DT	128	op->info.number = number;
869d81df DT	129	op->info.start = fl->fl_start;
869d81df DT	130	op->info.end = fl->fl_end;
586759f0	131	if (fl->fl_lmops && fl->fl_lmops->fl_grant) {
2066b58b DT	132	/* fl_owner is lockd which doesn't distinguish
	133	processes on the nfs client */
	134	op->info.owner = (__u64) fl->fl_pid;
586759f0 ME	135	xop->callback = fl->fl_lmops->fl_grant;
	136	locks_init_lock(&xop->flc);
	137	locks_copy_lock(&xop->flc, fl);
	138	xop->fl = fl;
	139	xop->file = file;
2066b58b DT	140	} else {
2066b58b DT	141	op->info.owner = (__u64)(long) fl->fl_owner;
586759f0	142	xop->callback = NULL;
2066b58b	143	}
869d81df DT	144
869d81df DT	145	send_op(op);
586759f0	146
901025d2 DT	147	if (xop->callback == NULL) {
	148	rv = wait_event_killable(recv_wq, (op->done != 0));
	149	if (rv == -ERESTARTSYS) {
	150	log_debug(ls, "dlm_posix_lock: wait killed %llx",
	151	(unsigned long long)number);
	152	spin_lock(&ops_lock);
	153	list_del(&op->list);
	154	spin_unlock(&ops_lock);
	155	kfree(xop);
	156	do_unlock_close(ls, number, file, fl);
	157	goto out;
	158	}
	159	} else {
bde74e4b	160	rv = FILE_LOCK_DEFERRED;
2402211a DT	161	goto out;
2402211a DT	162	}
869d81df DT	163
	164	spin_lock(&ops_lock);
	165	if (!list_empty(&op->list)) {
2402211a DT	166	log_error(ls, "dlm_posix_lock: op on list %llx",
2402211a DT	167	(unsigned long long)number);
869d81df DT	168	list_del(&op->list);
	169	}
	170	spin_unlock(&ops_lock);
	171
	172	rv = op->info.rv;
	173
	174	if (!rv) {
	175	if (posix_lock_file_wait(file, fl) < 0)
2402211a DT	176	log_error(ls, "dlm_posix_lock: vfs lock error %llx",
2402211a DT	177	(unsigned long long)number);
869d81df DT	178	}
869d81df DT	179
586759f0	180	kfree(xop);
2402211a DT	181	out:
2402211a DT	182	dlm_put_lockspace(ls);
586759f0 ME	183	return rv;
586759f0 ME	184	}
2402211a	185	EXPORT_SYMBOL_GPL(dlm_posix_lock);
586759f0	186
af901ca1	187	/* Returns failure iff a successful lock operation should be canceled */
2402211a	188	static int dlm_plock_callback(struct plock_op *op)
586759f0 ME	189	{
	190	struct file *file;
	191	struct file_lock *fl;
	192	struct file_lock *flc;
	193	int (notify)(void , void *, int) = NULL;
	194	struct plock_xop xop = (struct plock_xop )op;
	195	int rv = 0;
	196
	197	spin_lock(&ops_lock);
	198	if (!list_empty(&op->list)) {
2402211a DT	199	log_print("dlm_plock_callback: op on list %llx",
2402211a DT	200	(unsigned long long)op->info.number);
586759f0 ME	201	list_del(&op->list);
	202	}
	203	spin_unlock(&ops_lock);
	204
	205	/* check if the following 2 are still valid or make a copy */
	206	file = xop->file;
	207	flc = &xop->flc;
	208	fl = xop->fl;
	209	notify = xop->callback;
	210
	211	if (op->info.rv) {
24179f48	212	notify(fl, NULL, op->info.rv);
586759f0 ME	213	goto out;
	214	}
	215
	216	/* got fs lock; bookkeep locally as well: */
	217	flc->fl_flags &= ~FL_SLEEP;
	218	if (posix_lock_file(file, flc, NULL)) {
	219	/*
	220	* This can only happen in the case of kmalloc() failure.
	221	* The filesystem's own lock is the authoritative lock,
	222	* so a failure to get the lock locally is not a disaster.
2402211a	223	* As long as the fs cannot reliably cancel locks (especially
586759f0 ME	224	* in a low-memory situation), we're better off ignoring
	225	* this failure than trying to recover.
	226	*/
2402211a DT	227	log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
2402211a DT	228	(unsigned long long)op->info.number, file, fl);
586759f0 ME	229	}
586759f0 ME	230
24179f48	231	rv = notify(fl, NULL, 0);
586759f0 ME	232	if (rv) {
586759f0 ME	233	/* XXX: We need to cancel the fs lock here: */
2402211a DT	234	log_print("dlm_plock_callback: lock granted after lock request "
2402211a DT	235	"failed; dangling lock!\n");
586759f0 ME	236	goto out;
	237	}
	238
	239	out:
	240	kfree(xop);
869d81df DT	241	return rv;
	242	}
	243
2402211a DT	244	int dlm_posix_unlock(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	245	struct file_lock *fl)
869d81df	246	{
2402211a	247	struct dlm_ls *ls;
869d81df DT	248	struct plock_op *op;
	249	int rv;
	250
2402211a DT	251	ls = dlm_find_lockspace_local(lockspace);
	252	if (!ls)
	253	return -EINVAL;
	254
573c24c4	255	op = kzalloc(sizeof(*op), GFP_NOFS);
2402211a DT	256	if (!op) {
	257	rv = -ENOMEM;
	258	goto out;
	259	}
869d81df DT	260
869d81df DT	261	if (posix_lock_file_wait(file, fl) < 0)
2402211a DT	262	log_error(ls, "dlm_posix_unlock: vfs unlock error %llx",
2402211a DT	263	(unsigned long long)number);
869d81df	264
2402211a	265	op->info.optype = DLM_PLOCK_OP_UNLOCK;
3a2a9c96	266	op->info.pid = fl->fl_pid;
2402211a DT	267	op->info.fsid = ls->ls_global_id;
2402211a DT	268	op->info.number = number;
869d81df DT	269	op->info.start = fl->fl_start;
869d81df DT	270	op->info.end = fl->fl_end;
2066b58b DT	271	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
	272	op->info.owner = (__u64) fl->fl_pid;
	273	else
	274	op->info.owner = (__u64)(long) fl->fl_owner;
869d81df	275
901025d2 DT	276	if (fl->fl_flags & FL_CLOSE) {
	277	op->info.flags \|= DLM_PLOCK_FL_CLOSE;
	278	send_op(op);
	279	rv = 0;
	280	goto out;
	281	}
	282
869d81df DT	283	send_op(op);
	284	wait_event(recv_wq, (op->done != 0));
	285
	286	spin_lock(&ops_lock);
	287	if (!list_empty(&op->list)) {
2402211a DT	288	log_error(ls, "dlm_posix_unlock: op on list %llx",
2402211a DT	289	(unsigned long long)number);
869d81df DT	290	list_del(&op->list);
	291	}
	292	spin_unlock(&ops_lock);
	293
	294	rv = op->info.rv;
	295
586759f0 ME	296	if (rv == -ENOENT)
	297	rv = 0;
	298
869d81df	299	kfree(op);
2402211a DT	300	out:
2402211a DT	301	dlm_put_lockspace(ls);
869d81df DT	302	return rv;
869d81df DT	303	}
2402211a	304	EXPORT_SYMBOL_GPL(dlm_posix_unlock);
869d81df	305
2402211a DT	306	int dlm_posix_get(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	307	struct file_lock *fl)
869d81df	308	{
2402211a	309	struct dlm_ls *ls;
869d81df DT	310	struct plock_op *op;
	311	int rv;
	312
2402211a DT	313	ls = dlm_find_lockspace_local(lockspace);
	314	if (!ls)
	315	return -EINVAL;
	316
573c24c4	317	op = kzalloc(sizeof(*op), GFP_NOFS);
2402211a DT	318	if (!op) {
	319	rv = -ENOMEM;
	320	goto out;
	321	}
869d81df	322
2402211a	323	op->info.optype = DLM_PLOCK_OP_GET;
3a2a9c96	324	op->info.pid = fl->fl_pid;
869d81df	325	op->info.ex = (fl->fl_type == F_WRLCK);
2402211a DT	326	op->info.fsid = ls->ls_global_id;
2402211a DT	327	op->info.number = number;
869d81df DT	328	op->info.start = fl->fl_start;
869d81df DT	329	op->info.end = fl->fl_end;
2066b58b DT	330	if (fl->fl_lmops && fl->fl_lmops->fl_grant)
	331	op->info.owner = (__u64) fl->fl_pid;
	332	else
	333	op->info.owner = (__u64)(long) fl->fl_owner;
586759f0	334
869d81df DT	335	send_op(op);
	336	wait_event(recv_wq, (op->done != 0));
	337
	338	spin_lock(&ops_lock);
	339	if (!list_empty(&op->list)) {
2402211a DT	340	log_error(ls, "dlm_posix_get: op on list %llx",
2402211a DT	341	(unsigned long long)number);
869d81df DT	342	list_del(&op->list);
	343	}
	344	spin_unlock(&ops_lock);
	345
a7a2ff8a DT	346	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
	347	-ENOENT if there are no locks on the file */
	348
869d81df DT	349	rv = op->info.rv;
869d81df DT	350
586759f0 ME	351	fl->fl_type = F_UNLCK;
	352	if (rv == -ENOENT)
	353	rv = 0;
a7a2ff8a	354	else if (rv > 0) {
20d5a399	355	locks_init_lock(fl);
869d81df	356	fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
20d5a399	357	fl->fl_flags = FL_POSIX;
869d81df DT	358	fl->fl_pid = op->info.pid;
	359	fl->fl_start = op->info.start;
	360	fl->fl_end = op->info.end;
a7a2ff8a	361	rv = 0;
869d81df DT	362	}
	363
	364	kfree(op);
2402211a DT	365	out:
2402211a DT	366	dlm_put_lockspace(ls);
869d81df DT	367	return rv;
869d81df DT	368	}
2402211a	369	EXPORT_SYMBOL_GPL(dlm_posix_get);
869d81df DT	370
	371	/* a read copies out one plock request from the send list */
	372	static ssize_t dev_read(struct file file, char __user u, size_t count,
	373	loff_t *ppos)
	374	{
2402211a	375	struct dlm_plock_info info;
869d81df DT	376	struct plock_op *op = NULL;
	377
	378	if (count < sizeof(info))
	379	return -EINVAL;
	380
	381	spin_lock(&ops_lock);
	382	if (!list_empty(&send_list)) {
	383	op = list_entry(send_list.next, struct plock_op, list);
901025d2 DT	384	if (op->info.flags & DLM_PLOCK_FL_CLOSE)
	385	list_del(&op->list);
	386	else
	387	list_move(&op->list, &recv_list);
869d81df DT	388	memcpy(&info, &op->info, sizeof(info));
	389	}
	390	spin_unlock(&ops_lock);
	391
	392	if (!op)
	393	return -EAGAIN;
	394
901025d2 DT	395	/* there is no need to get a reply from userspace for unlocks
	396	that were generated by the vfs cleaning up for a close
	397	(the process did not make an unlock call). */
	398
	399	if (op->info.flags & DLM_PLOCK_FL_CLOSE)
	400	kfree(op);
	401
869d81df DT	402	if (copy_to_user(u, &info, sizeof(info)))
	403	return -EFAULT;
	404	return sizeof(info);
	405	}
	406
	407	/* a write copies in one plock result that should match a plock_op
	408	on the recv list */
	409	static ssize_t dev_write(struct file file, const char __user u, size_t count,
	410	loff_t *ppos)
	411	{
2402211a	412	struct dlm_plock_info info;
869d81df	413	struct plock_op *op;
c78a87d0	414	int found = 0, do_callback = 0;
869d81df DT	415
	416	if (count != sizeof(info))
	417	return -EINVAL;
	418
	419	if (copy_from_user(&info, u, sizeof(info)))
	420	return -EFAULT;
	421
	422	if (check_version(&info))
	423	return -EINVAL;
	424
	425	spin_lock(&ops_lock);
	426	list_for_each_entry(op, &recv_list, list) {
c78a87d0 DT	427	if (op->info.fsid == info.fsid &&
c78a87d0 DT	428	op->info.number == info.number &&
08eac93a	429	op->info.owner == info.owner) {
c78a87d0	430	struct plock_xop xop = (struct plock_xop )op;
869d81df	431	list_del_init(&op->list);
869d81df	432	memcpy(&op->info, &info, sizeof(info));
c78a87d0 DT	433	if (xop->callback)
	434	do_callback = 1;
	435	else
	436	op->done = 1;
	437	found = 1;
869d81df DT	438	break;
	439	}
	440	}
	441	spin_unlock(&ops_lock);
	442
586759f0	443	if (found) {
c78a87d0	444	if (do_callback)
817d10ba	445	dlm_plock_callback(op);
586759f0 ME	446	else
	447	wake_up(&recv_wq);
	448	} else
2402211a DT	449	log_print("dev_write no op %x %llx", info.fsid,
2402211a DT	450	(unsigned long long)info.number);
869d81df DT	451	return count;
	452	}
	453
	454	static unsigned int dev_poll(struct file file, poll_table wait)
	455	{
cee23c79 DC	456	unsigned int mask = 0;
cee23c79 DC	457
869d81df DT	458	poll_wait(file, &send_wq, wait);
	459
	460	spin_lock(&ops_lock);
cee23c79 DC	461	if (!list_empty(&send_list))
cee23c79 DC	462	mask = POLLIN \| POLLRDNORM;
869d81df	463	spin_unlock(&ops_lock);
cee23c79 DC	464
cee23c79 DC	465	return mask;
869d81df DT	466	}
869d81df DT	467
00977a59	468	static const struct file_operations dev_fops = {
869d81df DT	469	.read = dev_read,
	470	.write = dev_write,
	471	.poll = dev_poll,
6038f373 AB	472	.owner = THIS_MODULE,
6038f373 AB	473	.llseek = noop_llseek,
869d81df DT	474	};
	475
	476	static struct miscdevice plock_dev_misc = {
	477	.minor = MISC_DYNAMIC_MINOR,
2402211a	478	.name = DLM_PLOCK_MISC_NAME,
869d81df DT	479	.fops = &dev_fops
	480	};
	481
2402211a	482	int dlm_plock_init(void)
869d81df DT	483	{
	484	int rv;
	485
	486	spin_lock_init(&ops_lock);
	487	INIT_LIST_HEAD(&send_list);
	488	INIT_LIST_HEAD(&recv_list);
	489	init_waitqueue_head(&send_wq);
	490	init_waitqueue_head(&recv_wq);
	491
	492	rv = misc_register(&plock_dev_misc);
	493	if (rv)
2402211a	494	log_print("dlm_plock_init: misc_register failed %d", rv);
869d81df DT	495	return rv;
	496	}
	497
2402211a	498	void dlm_plock_exit(void)
869d81df DT	499	{
869d81df DT	500	if (misc_deregister(&plock_dev_misc) < 0)
2402211a	501	log_print("dlm_plock_exit: misc_deregister failed");
869d81df DT	502	}
869d81df DT	503