[mirror_ubuntu-jammy-kernel.git] / fs / dlm / plock.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2008 Red Hat, Inc.  All rights reserved.
 */

#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;
	int (*callback)(struct file_lock *fl, int result);
	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->lm_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->lm_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->lm_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_interruptible(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 (locks_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)(struct file_lock *fl, int result) = 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, 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, 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;
	unsigned char fl_flags = fl->fl_flags;

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

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

	/* cause the vfs unlock to return ENOENT if lock is not found */
	fl->fl_flags |= FL_EXISTS;

	rv = locks_lock_file_wait(file, fl);
	if (rv == -ENOENT) {
		rv = 0;
		goto out_free;
	}
	if (rv < 0) {
		log_error(ls, "dlm_posix_unlock: vfs unlock error %d %llx",
			  rv, (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->lm_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;

out_free:
	kfree(op);
out:
	dlm_put_lockspace(ls);
	fl->fl_flags = fl_flags;
	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->lm_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 __poll_t dev_poll(struct file *file, poll_table *wait)
{
	__poll_t mask = 0;

	poll_wait(file, &send_wq, wait);

	spin_lock(&ops_lock);
	if (!list_empty(&send_list))
		mask = EPOLLIN | EPOLLRDNORM;
	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)
{
	misc_deregister(&plock_dev_misc);
}
Commit	Line	Data
7336d0e6	1	// SPDX-License-Identifier: GPL-2.0-only
869d81df	2	/*
2402211a	3	* Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
869d81df DT	4	*/
869d81df DT	5
2402211a	6	#include <linux/fs.h>
869d81df	7	#include <linux/miscdevice.h>
bd01f843	8	#include <linux/poll.h>
2402211a DT	9	#include <linux/dlm.h>
2402211a DT	10	#include <linux/dlm_plock.h>
5a0e3ad6	11	#include <linux/slab.h>
869d81df	12
2402211a DT	13	#include "dlm_internal.h"
2402211a DT	14	#include "lockspace.h"
869d81df DT	15
	16	static spinlock_t ops_lock;
	17	static struct list_head send_list;
	18	static struct list_head recv_list;
	19	static wait_queue_head_t send_wq;
	20	static wait_queue_head_t recv_wq;
	21
	22	struct plock_op {
	23	struct list_head list;
	24	int done;
2402211a	25	struct dlm_plock_info info;
869d81df DT	26	};
869d81df DT	27
586759f0 ME	28	struct plock_xop {
586759f0 ME	29	struct plock_op xop;
d0449b90	30	int (callback)(struct file_lock fl, int result);
586759f0 ME	31	void *fl;
	32	void *file;
	33	struct file_lock flc;
	34	};
	35
	36
2402211a	37	static inline void set_version(struct dlm_plock_info *info)
869d81df	38	{
2402211a DT	39	info->version[0] = DLM_PLOCK_VERSION_MAJOR;
	40	info->version[1] = DLM_PLOCK_VERSION_MINOR;
	41	info->version[2] = DLM_PLOCK_VERSION_PATCH;
869d81df DT	42	}
869d81df DT	43
2402211a	44	static int check_version(struct dlm_plock_info *info)
869d81df	45	{
2402211a DT	46	if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) \|\|
	47	(DLM_PLOCK_VERSION_MINOR < info->version[1])) {
	48	log_print("plock device version mismatch: "
869d81df	49	"kernel (%u.%u.%u), user (%u.%u.%u)",
2402211a DT	50	DLM_PLOCK_VERSION_MAJOR,
	51	DLM_PLOCK_VERSION_MINOR,
	52	DLM_PLOCK_VERSION_PATCH,
869d81df DT	53	info->version[0],
	54	info->version[1],
	55	info->version[2]);
	56	return -EINVAL;
	57	}
	58	return 0;
	59	}
	60
	61	static void send_op(struct plock_op *op)
	62	{
	63	set_version(&op->info);
	64	INIT_LIST_HEAD(&op->list);
	65	spin_lock(&ops_lock);
	66	list_add_tail(&op->list, &send_list);
	67	spin_unlock(&ops_lock);
	68	wake_up(&send_wq);
	69	}
	70
901025d2 DT	71	/* If a process was killed while waiting for the only plock on a file,
	72	locks_remove_posix will not see any lock on the file so it won't
	73	send an unlock-close to us to pass on to userspace to clean up the
	74	abandoned waiter. So, we have to insert the unlock-close when the
	75	lock call is interrupted. */
	76
	77	static void do_unlock_close(struct dlm_ls *ls, u64 number,
	78	struct file file, struct file_lock fl)
	79	{
	80	struct plock_op *op;
	81
	82	op = kzalloc(sizeof(*op), GFP_NOFS);
	83	if (!op)
	84	return;
	85
	86	op->info.optype = DLM_PLOCK_OP_UNLOCK;
	87	op->info.pid = fl->fl_pid;
	88	op->info.fsid = ls->ls_global_id;
	89	op->info.number = number;
	90	op->info.start = 0;
	91	op->info.end = OFFSET_MAX;
8fb47a4f	92	if (fl->fl_lmops && fl->fl_lmops->lm_grant)
901025d2 DT	93	op->info.owner = (__u64) fl->fl_pid;
	94	else
	95	op->info.owner = (__u64)(long) fl->fl_owner;
	96
	97	op->info.flags \|= DLM_PLOCK_FL_CLOSE;
	98	send_op(op);
	99	}
	100
2402211a DT	101	int dlm_posix_lock(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	102	int cmd, struct file_lock *fl)
869d81df	103	{
2402211a	104	struct dlm_ls *ls;
869d81df	105	struct plock_op *op;
586759f0	106	struct plock_xop *xop;
869d81df DT	107	int rv;
869d81df DT	108
2402211a DT	109	ls = dlm_find_lockspace_local(lockspace);
	110	if (!ls)
	111	return -EINVAL;
	112
573c24c4	113	xop = kzalloc(sizeof(*xop), GFP_NOFS);
2402211a DT	114	if (!xop) {
	115	rv = -ENOMEM;
	116	goto out;
	117	}
869d81df	118
586759f0	119	op = &xop->xop;
2402211a	120	op->info.optype = DLM_PLOCK_OP_LOCK;
3a2a9c96	121	op->info.pid = fl->fl_pid;
869d81df DT	122	op->info.ex = (fl->fl_type == F_WRLCK);
869d81df DT	123	op->info.wait = IS_SETLKW(cmd);
2402211a DT	124	op->info.fsid = ls->ls_global_id;
2402211a DT	125	op->info.number = number;
869d81df DT	126	op->info.start = fl->fl_start;
869d81df DT	127	op->info.end = fl->fl_end;
8fb47a4f	128	if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
2066b58b DT	129	/* fl_owner is lockd which doesn't distinguish
	130	processes on the nfs client */
	131	op->info.owner = (__u64) fl->fl_pid;
8fb47a4f	132	xop->callback = fl->fl_lmops->lm_grant;
586759f0 ME	133	locks_init_lock(&xop->flc);
	134	locks_copy_lock(&xop->flc, fl);
	135	xop->fl = fl;
	136	xop->file = file;
2066b58b DT	137	} else {
2066b58b DT	138	op->info.owner = (__u64)(long) fl->fl_owner;
586759f0	139	xop->callback = NULL;
2066b58b	140	}
869d81df DT	141
869d81df DT	142	send_op(op);
586759f0	143
901025d2	144	if (xop->callback == NULL) {
a6b1533e	145	rv = wait_event_interruptible(recv_wq, (op->done != 0));
901025d2 DT	146	if (rv == -ERESTARTSYS) {
	147	log_debug(ls, "dlm_posix_lock: wait killed %llx",
	148	(unsigned long long)number);
	149	spin_lock(&ops_lock);
	150	list_del(&op->list);
	151	spin_unlock(&ops_lock);
	152	kfree(xop);
	153	do_unlock_close(ls, number, file, fl);
	154	goto out;
	155	}
	156	} else {
bde74e4b	157	rv = FILE_LOCK_DEFERRED;
2402211a DT	158	goto out;
2402211a DT	159	}
869d81df DT	160
	161	spin_lock(&ops_lock);
	162	if (!list_empty(&op->list)) {
2402211a DT	163	log_error(ls, "dlm_posix_lock: op on list %llx",
2402211a DT	164	(unsigned long long)number);
869d81df DT	165	list_del(&op->list);
	166	}
	167	spin_unlock(&ops_lock);
	168
	169	rv = op->info.rv;
	170
	171	if (!rv) {
4f656367	172	if (locks_lock_file_wait(file, fl) < 0)
2402211a DT	173	log_error(ls, "dlm_posix_lock: vfs lock error %llx",
2402211a DT	174	(unsigned long long)number);
869d81df DT	175	}
869d81df DT	176
586759f0	177	kfree(xop);
2402211a DT	178	out:
2402211a DT	179	dlm_put_lockspace(ls);
586759f0 ME	180	return rv;
586759f0 ME	181	}
2402211a	182	EXPORT_SYMBOL_GPL(dlm_posix_lock);
586759f0	183
af901ca1	184	/* Returns failure iff a successful lock operation should be canceled */
2402211a	185	static int dlm_plock_callback(struct plock_op *op)
586759f0 ME	186	{
	187	struct file *file;
	188	struct file_lock *fl;
	189	struct file_lock *flc;
d0449b90	190	int (notify)(struct file_lock fl, int result) = NULL;
586759f0 ME	191	struct plock_xop xop = (struct plock_xop )op;
	192	int rv = 0;
	193
	194	spin_lock(&ops_lock);
	195	if (!list_empty(&op->list)) {
2402211a DT	196	log_print("dlm_plock_callback: op on list %llx",
2402211a DT	197	(unsigned long long)op->info.number);
586759f0 ME	198	list_del(&op->list);
	199	}
	200	spin_unlock(&ops_lock);
	201
	202	/* check if the following 2 are still valid or make a copy */
	203	file = xop->file;
	204	flc = &xop->flc;
	205	fl = xop->fl;
	206	notify = xop->callback;
	207
	208	if (op->info.rv) {
d0449b90	209	notify(fl, op->info.rv);
586759f0 ME	210	goto out;
	211	}
	212
	213	/* got fs lock; bookkeep locally as well: */
	214	flc->fl_flags &= ~FL_SLEEP;
	215	if (posix_lock_file(file, flc, NULL)) {
	216	/*
	217	* This can only happen in the case of kmalloc() failure.
	218	* The filesystem's own lock is the authoritative lock,
	219	* so a failure to get the lock locally is not a disaster.
2402211a	220	* As long as the fs cannot reliably cancel locks (especially
586759f0 ME	221	* in a low-memory situation), we're better off ignoring
	222	* this failure than trying to recover.
	223	*/
2402211a DT	224	log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
2402211a DT	225	(unsigned long long)op->info.number, file, fl);
586759f0 ME	226	}
586759f0 ME	227
d0449b90	228	rv = notify(fl, 0);
586759f0 ME	229	if (rv) {
586759f0 ME	230	/* XXX: We need to cancel the fs lock here: */
2402211a DT	231	log_print("dlm_plock_callback: lock granted after lock request "
2402211a DT	232	"failed; dangling lock!\n");
586759f0 ME	233	goto out;
	234	}
	235
	236	out:
	237	kfree(xop);
869d81df DT	238	return rv;
	239	}
	240
2402211a DT	241	int dlm_posix_unlock(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	242	struct file_lock *fl)
869d81df	243	{
2402211a	244	struct dlm_ls *ls;
869d81df DT	245	struct plock_op *op;
869d81df DT	246	int rv;
90008318	247	unsigned char fl_flags = fl->fl_flags;
869d81df	248
2402211a DT	249	ls = dlm_find_lockspace_local(lockspace);
	250	if (!ls)
	251	return -EINVAL;
	252
573c24c4	253	op = kzalloc(sizeof(*op), GFP_NOFS);
2402211a DT	254	if (!op) {
	255	rv = -ENOMEM;
	256	goto out;
	257	}
869d81df	258
90008318 DT	259	/* cause the vfs unlock to return ENOENT if lock is not found */
	260	fl->fl_flags \|= FL_EXISTS;
	261
4f656367	262	rv = locks_lock_file_wait(file, fl);
90008318 DT	263	if (rv == -ENOENT) {
	264	rv = 0;
	265	goto out_free;
	266	}
	267	if (rv < 0) {
	268	log_error(ls, "dlm_posix_unlock: vfs unlock error %d %llx",
	269	rv, (unsigned long long)number);
	270	}
869d81df	271
2402211a	272	op->info.optype = DLM_PLOCK_OP_UNLOCK;
3a2a9c96	273	op->info.pid = fl->fl_pid;
2402211a DT	274	op->info.fsid = ls->ls_global_id;
2402211a DT	275	op->info.number = number;
869d81df DT	276	op->info.start = fl->fl_start;
869d81df DT	277	op->info.end = fl->fl_end;
8fb47a4f	278	if (fl->fl_lmops && fl->fl_lmops->lm_grant)
2066b58b DT	279	op->info.owner = (__u64) fl->fl_pid;
	280	else
	281	op->info.owner = (__u64)(long) fl->fl_owner;
869d81df	282
901025d2 DT	283	if (fl->fl_flags & FL_CLOSE) {
	284	op->info.flags \|= DLM_PLOCK_FL_CLOSE;
	285	send_op(op);
	286	rv = 0;
	287	goto out;
	288	}
	289
869d81df DT	290	send_op(op);
	291	wait_event(recv_wq, (op->done != 0));
	292
	293	spin_lock(&ops_lock);
	294	if (!list_empty(&op->list)) {
2402211a DT	295	log_error(ls, "dlm_posix_unlock: op on list %llx",
2402211a DT	296	(unsigned long long)number);
869d81df DT	297	list_del(&op->list);
	298	}
	299	spin_unlock(&ops_lock);
	300
	301	rv = op->info.rv;
	302
586759f0 ME	303	if (rv == -ENOENT)
	304	rv = 0;
	305
90008318	306	out_free:
869d81df	307	kfree(op);
2402211a DT	308	out:
2402211a DT	309	dlm_put_lockspace(ls);
90008318	310	fl->fl_flags = fl_flags;
869d81df DT	311	return rv;
869d81df DT	312	}
2402211a	313	EXPORT_SYMBOL_GPL(dlm_posix_unlock);
869d81df	314
2402211a DT	315	int dlm_posix_get(dlm_lockspace_t lockspace, u64 number, struct file file,
2402211a DT	316	struct file_lock *fl)
869d81df	317	{
2402211a	318	struct dlm_ls *ls;
869d81df DT	319	struct plock_op *op;
	320	int rv;
	321
2402211a DT	322	ls = dlm_find_lockspace_local(lockspace);
	323	if (!ls)
	324	return -EINVAL;
	325
573c24c4	326	op = kzalloc(sizeof(*op), GFP_NOFS);
2402211a DT	327	if (!op) {
	328	rv = -ENOMEM;
	329	goto out;
	330	}
869d81df	331
2402211a	332	op->info.optype = DLM_PLOCK_OP_GET;
3a2a9c96	333	op->info.pid = fl->fl_pid;
869d81df	334	op->info.ex = (fl->fl_type == F_WRLCK);
2402211a DT	335	op->info.fsid = ls->ls_global_id;
2402211a DT	336	op->info.number = number;
869d81df DT	337	op->info.start = fl->fl_start;
869d81df DT	338	op->info.end = fl->fl_end;
8fb47a4f	339	if (fl->fl_lmops && fl->fl_lmops->lm_grant)
2066b58b DT	340	op->info.owner = (__u64) fl->fl_pid;
	341	else
	342	op->info.owner = (__u64)(long) fl->fl_owner;
586759f0	343
869d81df DT	344	send_op(op);
	345	wait_event(recv_wq, (op->done != 0));
	346
	347	spin_lock(&ops_lock);
	348	if (!list_empty(&op->list)) {
2402211a DT	349	log_error(ls, "dlm_posix_get: op on list %llx",
2402211a DT	350	(unsigned long long)number);
869d81df DT	351	list_del(&op->list);
	352	}
	353	spin_unlock(&ops_lock);
	354
a7a2ff8a DT	355	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
	356	-ENOENT if there are no locks on the file */
	357
869d81df DT	358	rv = op->info.rv;
869d81df DT	359
586759f0 ME	360	fl->fl_type = F_UNLCK;
	361	if (rv == -ENOENT)
	362	rv = 0;
a7a2ff8a	363	else if (rv > 0) {
20d5a399	364	locks_init_lock(fl);
869d81df	365	fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
20d5a399	366	fl->fl_flags = FL_POSIX;
9d5b86ac	367	fl->fl_pid = -op->info.pid;
869d81df DT	368	fl->fl_start = op->info.start;
869d81df DT	369	fl->fl_end = op->info.end;
a7a2ff8a	370	rv = 0;
869d81df DT	371	}
	372
	373	kfree(op);
2402211a DT	374	out:
2402211a DT	375	dlm_put_lockspace(ls);
869d81df DT	376	return rv;
869d81df DT	377	}
2402211a	378	EXPORT_SYMBOL_GPL(dlm_posix_get);
869d81df DT	379
	380	/* a read copies out one plock request from the send list */
	381	static ssize_t dev_read(struct file file, char __user u, size_t count,
	382	loff_t *ppos)
	383	{
2402211a	384	struct dlm_plock_info info;
869d81df DT	385	struct plock_op *op = NULL;
	386
	387	if (count < sizeof(info))
	388	return -EINVAL;
	389
	390	spin_lock(&ops_lock);
	391	if (!list_empty(&send_list)) {
	392	op = list_entry(send_list.next, struct plock_op, list);
901025d2 DT	393	if (op->info.flags & DLM_PLOCK_FL_CLOSE)
	394	list_del(&op->list);
	395	else
	396	list_move(&op->list, &recv_list);
869d81df DT	397	memcpy(&info, &op->info, sizeof(info));
	398	}
	399	spin_unlock(&ops_lock);
	400
	401	if (!op)
	402	return -EAGAIN;
	403
901025d2 DT	404	/* there is no need to get a reply from userspace for unlocks
	405	that were generated by the vfs cleaning up for a close
	406	(the process did not make an unlock call). */
	407
	408	if (op->info.flags & DLM_PLOCK_FL_CLOSE)
	409	kfree(op);
	410
869d81df DT	411	if (copy_to_user(u, &info, sizeof(info)))
	412	return -EFAULT;
	413	return sizeof(info);
	414	}
	415
	416	/* a write copies in one plock result that should match a plock_op
	417	on the recv list */
	418	static ssize_t dev_write(struct file file, const char __user u, size_t count,
	419	loff_t *ppos)
	420	{
2402211a	421	struct dlm_plock_info info;
869d81df	422	struct plock_op *op;
c78a87d0	423	int found = 0, do_callback = 0;
869d81df DT	424
	425	if (count != sizeof(info))
	426	return -EINVAL;
	427
	428	if (copy_from_user(&info, u, sizeof(info)))
	429	return -EFAULT;
	430
	431	if (check_version(&info))
	432	return -EINVAL;
	433
	434	spin_lock(&ops_lock);
	435	list_for_each_entry(op, &recv_list, list) {
c78a87d0 DT	436	if (op->info.fsid == info.fsid &&
c78a87d0 DT	437	op->info.number == info.number &&
08eac93a	438	op->info.owner == info.owner) {
c78a87d0	439	struct plock_xop xop = (struct plock_xop )op;
869d81df	440	list_del_init(&op->list);
869d81df	441	memcpy(&op->info, &info, sizeof(info));
c78a87d0 DT	442	if (xop->callback)
	443	do_callback = 1;
	444	else
	445	op->done = 1;
	446	found = 1;
869d81df DT	447	break;
	448	}
	449	}
	450	spin_unlock(&ops_lock);
	451
586759f0	452	if (found) {
c78a87d0	453	if (do_callback)
817d10ba	454	dlm_plock_callback(op);
586759f0 ME	455	else
	456	wake_up(&recv_wq);
	457	} else
2402211a DT	458	log_print("dev_write no op %x %llx", info.fsid,
2402211a DT	459	(unsigned long long)info.number);
869d81df DT	460	return count;
	461	}
	462
076ccb76	463	static __poll_t dev_poll(struct file file, poll_table wait)
869d81df	464	{
076ccb76	465	__poll_t mask = 0;
cee23c79	466
869d81df DT	467	poll_wait(file, &send_wq, wait);
	468
	469	spin_lock(&ops_lock);
cee23c79	470	if (!list_empty(&send_list))
a9a08845	471	mask = EPOLLIN \| EPOLLRDNORM;
869d81df	472	spin_unlock(&ops_lock);
cee23c79 DC	473
cee23c79 DC	474	return mask;
869d81df DT	475	}
869d81df DT	476
00977a59	477	static const struct file_operations dev_fops = {
869d81df DT	478	.read = dev_read,
	479	.write = dev_write,
	480	.poll = dev_poll,
6038f373 AB	481	.owner = THIS_MODULE,
6038f373 AB	482	.llseek = noop_llseek,
869d81df DT	483	};
	484
	485	static struct miscdevice plock_dev_misc = {
	486	.minor = MISC_DYNAMIC_MINOR,
2402211a	487	.name = DLM_PLOCK_MISC_NAME,
869d81df DT	488	.fops = &dev_fops
	489	};
	490
2402211a	491	int dlm_plock_init(void)
869d81df DT	492	{
	493	int rv;
	494
	495	spin_lock_init(&ops_lock);
	496	INIT_LIST_HEAD(&send_list);
	497	INIT_LIST_HEAD(&recv_list);
	498	init_waitqueue_head(&send_wq);
	499	init_waitqueue_head(&recv_wq);
	500
	501	rv = misc_register(&plock_dev_misc);
	502	if (rv)
2402211a	503	log_print("dlm_plock_init: misc_register failed %d", rv);
869d81df DT	504	return rv;
	505	}
	506
2402211a	507	void dlm_plock_exit(void)
869d81df	508	{
f368ed60	509	misc_deregister(&plock_dev_misc);
869d81df DT	510	}
869d81df DT	511