fs/gfs2/locking/dlm/plock.c - arm/linux-arm64-legacy - Git at Google

 /*
  * 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 <linux/poll.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");
 }
	/*
	* 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 <linux/poll.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");
	}