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[PATCH] w1: use kthread api.
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This patch removes old-style kernel thread initialization
and changes w1 to use kthread api.
It is based on Christoph Hellwig <[email protected]> work.

Signed-off-by: Evgeniy Polyakov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Evgeniy Polyakov authored and gregkh committed Mar 24, 2006
1 parent f73b5e7 commit 674a396
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Showing 3 changed files with 28 additions and 65 deletions.
56 changes: 16 additions & 40 deletions drivers/w1/w1.c
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kthread.h>

#include <asm/atomic.h>

Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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.
Expand All @@ -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) {
Expand Down Expand Up @@ -789,25 +773,19 @@ static int w1_control(void *data)
}
}

complete_and_exit(&w1_control_complete, 0);
return 0;
}

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)
Expand Down Expand Up @@ -840,7 +818,6 @@ int w1_process(void *data)
}

atomic_dec(&dev->refcnt);
complete_and_exit(&dev->dev_exited, 0);

return 0;
}
Expand Down Expand Up @@ -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;
}

Expand All @@ -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);
Expand Down
3 changes: 1 addition & 2 deletions drivers/w1/w1.h
Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand Down
34 changes: 11 additions & 23 deletions drivers/w1/w1_int.c
Original file line number Diff line number Diff line change
Expand Up @@ -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"
Expand Down Expand Up @@ -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;
Expand All @@ -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);
Expand Down Expand Up @@ -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;
}

Expand All @@ -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);

Expand All @@ -160,26 +152,22 @@ 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))
flush_signals(current);
}

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);

Expand Down

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