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Commit 674a396c authored by Evgeniy Polyakov's avatar Evgeniy Polyakov Committed by Greg Kroah-Hartman
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[PATCH] w1: use kthread api. 



This patch removes old-style kernel thread initialization
and changes w1 to use kthread api.
It is based on Christoph Hellwig <hch@lst.de> work.

Signed-off-by: default avatarEvgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent f73b5e79

drivers/w1/w1.c

+16 −40
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/device.h>

#include <linux/slab.h>

#include <linux/sched.h>

#include <linux/kthread.h>



#include <asm/atomic.h>
@@ -57,9 +58,7 @@ module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); 
DEFINE_SPINLOCK(w1_mlock);

LIST_HEAD(w1_masters);



static pid_t control_thread;

static int control_needs_exit;

static DECLARE_COMPLETION(w1_control_complete);

static struct task_struct *w1_control_thread;



static int w1_master_match(struct device *dev, struct device_driver *drv)

{
@@ -717,22 +716,16 @@ static int w1_control(void *data) 
{

	struct w1_slave *sl, *sln;

	struct w1_master *dev, *n;

	int err, have_to_wait = 0;

	int have_to_wait = 0;



	daemonize("w1_control");

	allow_signal(SIGTERM);



	while (!control_needs_exit || have_to_wait) {

	while (!kthread_should_stop() || have_to_wait) {

		have_to_wait = 0;



		try_to_freeze();

		msleep_interruptible(w1_control_timeout * 1000);



		if (signal_pending(current))

			flush_signals(current);



		list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {

			if (!control_needs_exit && !dev->flags)

			if (!kthread_should_stop() && !dev->flags)

				continue;

			/*

			 * Little race: we can create thread but not set the flag.
@@ -743,21 +736,12 @@ static int w1_control(void *data) 
				continue;

			}



			if (control_needs_exit) {

			if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {

				set_bit(W1_MASTER_NEED_EXIT, &dev->flags);



				err = kill_proc(dev->kpid, SIGTERM, 1);

				if (err)

					dev_err(&dev->dev,

						 "Failed to send signal to w1 kernel thread %d.\n",

						 dev->kpid);

			}



			if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {

				wait_for_completion(&dev->dev_exited);

				spin_lock_bh(&w1_mlock);

				spin_lock(&w1_mlock);

				list_del(&dev->w1_master_entry);

				spin_unlock_bh(&w1_mlock);

				spin_unlock(&w1_mlock);



				down(&dev->mutex);

				list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
@@ -789,7 +773,7 @@ static int w1_control(void *data) 
		}

	}



	complete_and_exit(&w1_control_complete, 0);

	return 0;

}



int w1_process(void *data)
@@ -797,17 +781,11 @@ int w1_process(void *data) 
	struct w1_master *dev = (struct w1_master *) data;

	struct w1_slave *sl, *sln;



	daemonize("%s", dev->name);

	allow_signal(SIGTERM);



	while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {

	while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {

		try_to_freeze();

		msleep_interruptible(w1_timeout * 1000);



		if (signal_pending(current))

			flush_signals(current);



		if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags))

		if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags))

			break;



		if (!dev->initialized)
@@ -840,7 +818,6 @@ int w1_process(void *data) 
	}



	atomic_dec(&dev->refcnt);

	complete_and_exit(&dev->dev_exited, 0);



	return 0;

}
@@ -873,11 +850,11 @@ static int w1_init(void) 
		goto err_out_master_unregister;

	}



	control_thread = kernel_thread(&w1_control, NULL, 0);

	if (control_thread < 0) {

	w1_control_thread = kthread_run(w1_control, NULL, "w1_control");

	if (IS_ERR(w1_control_thread)) {

		retval = PTR_ERR(w1_control_thread);

		printk(KERN_ERR "Failed to create control thread. err=%d\n",

			control_thread);

		retval = control_thread;

			retval);

		goto err_out_slave_unregister;

	}
@@ -903,8 +880,7 @@ static void w1_fini(void) 
	list_for_each_entry(dev, &w1_masters, w1_master_entry)

		__w1_remove_master_device(dev);



	control_needs_exit = 1;

	wait_for_completion(&w1_control_complete);

	kthread_stop(w1_control_thread);



	driver_unregister(&w1_slave_driver);

	driver_unregister(&w1_master_driver);

drivers/w1/w1.h

+1 −2
Original line number Diff line number Diff line
@@ -172,12 +172,11 @@ struct w1_master 


	long			flags;



	pid_t			kpid;

	struct task_struct	*thread;

	struct semaphore	mutex;



	struct device_driver	*driver;

	struct device		dev;

	struct completion	dev_exited;



	struct w1_bus_master	*bus_master;

drivers/w1/w1_int.c

+11 −23
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/kernel.h>

#include <linux/list.h>

#include <linux/delay.h>

#include <linux/kthread.h>



#include "w1.h"

#include "w1_log.h"
@@ -56,7 +57,6 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, 
	dev->max_slave_count	= slave_count;

	dev->slave_count	= 0;

	dev->attempts		= 0;

	dev->kpid		= -1;

	dev->initialized	= 0;

	dev->id			= id;

	dev->slave_ttl		= slave_ttl;
@@ -67,8 +67,6 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, 
	INIT_LIST_HEAD(&dev->slist);

	init_MUTEX(&dev->mutex);



	init_completion(&dev->dev_exited);



	memcpy(&dev->dev, device, sizeof(struct device));

	snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),

		  "w1_bus_master%u", dev->id);
@@ -116,12 +114,12 @@ int w1_add_master_device(struct w1_bus_master *master) 
	if (!dev)

		return -ENOMEM;



	dev->kpid = kernel_thread(&w1_process, dev, 0);

	if (dev->kpid < 0) {

	dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);

	if (IS_ERR(dev->thread)) {

		retval = PTR_ERR(dev->thread);

		dev_err(&dev->dev,

			 "Failed to create new kernel thread. err=%d\n",

			 dev->kpid);

		retval = dev->kpid;

			 retval);

		goto err_out_free_dev;

	}
@@ -138,20 +136,14 @@ int w1_add_master_device(struct w1_bus_master *master) 
	spin_unlock(&w1_mlock);



	msg.id.mst.id = dev->id;

	msg.id.mst.pid = dev->kpid;

	msg.id.mst.pid = dev->thread->pid;

	msg.type = W1_MASTER_ADD;

	w1_netlink_send(dev, &msg);



	return 0;



err_out_kill_thread:

	set_bit(W1_MASTER_NEED_EXIT, &dev->flags);

	if (kill_proc(dev->kpid, SIGTERM, 1))

		dev_err(&dev->dev,

			 "Failed to send signal to w1 kernel thread %d.\n",

			 dev->kpid);

	wait_for_completion(&dev->dev_exited);



	kthread_stop(dev->thread);

err_out_free_dev:

	w1_free_dev(dev);
@@ -160,18 +152,14 @@ int w1_add_master_device(struct w1_bus_master *master) 


void __w1_remove_master_device(struct w1_master *dev)

{

	int err;

	struct w1_netlink_msg msg;

	pid_t pid = dev->thread->pid;



	set_bit(W1_MASTER_NEED_EXIT, &dev->flags);

	err = kill_proc(dev->kpid, SIGTERM, 1);

	if (err)

		dev_err(&dev->dev,

			 "%s: Failed to send signal to w1 kernel thread %d.\n",

			 __func__, dev->kpid);

	kthread_stop(dev->thread);



	while (atomic_read(&dev->refcnt)) {

		dev_dbg(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",

		dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",

				dev->name, atomic_read(&dev->refcnt));



		if (msleep_interruptible(1000))
@@ -179,7 +167,7 @@ void __w1_remove_master_device(struct w1_master *dev) 
	}



	msg.id.mst.id = dev->id;

	msg.id.mst.pid = dev->kpid;

	msg.id.mst.pid = pid;

	msg.type = W1_MASTER_REMOVE;

	w1_netlink_send(dev, &msg);