[PATCH] w1: use kthread_ API
From: Christoph Hellwig
Date: Tue Feb 14 2006 - 12:46:32 EST
Use the kthread_ API instead of opencoding lots of hairy code for kernel
thread creation and teardown.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: linux-2.6/drivers/w1/w1.c
===================================================================
--- linux-2.6.orig/drivers/w1/w1.c 2006-01-05 16:43:19.000000000 +0100
+++ linux-2.6/drivers/w1/w1.c 2006-02-14 18:01:58.000000000 +0100
@@ -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 @@
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)
{
@@ -712,22 +711,16 @@
{
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.
@@ -738,18 +731,9 @@
continue;
}
- if (control_needs_exit) {
- set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
+ if (kthread_should_stop()) {
+ kthread_stop(dev->thread);
- 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);
list_del(&dev->w1_master_entry);
spin_unlock_bh(&w1_mlock);
@@ -784,7 +768,7 @@
}
}
- complete_and_exit(&w1_control_complete, 0);
+ return 0;
}
int w1_process(void *data)
@@ -792,17 +776,11 @@
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()) {
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())
break;
if (!dev->initialized)
@@ -835,8 +813,6 @@
}
atomic_dec(&dev->refcnt);
- complete_and_exit(&dev->dev_exited, 0);
-
return 0;
}
@@ -868,11 +844,11 @@
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;
}
@@ -898,8 +874,7 @@
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);
Index: linux-2.6/drivers/w1/w1.h
===================================================================
--- linux-2.6.orig/drivers/w1/w1.h 2005-12-27 18:30:31.000000000 +0100
+++ linux-2.6/drivers/w1/w1.h 2006-02-14 18:01:34.000000000 +0100
@@ -149,7 +149,6 @@
void (*search)(unsigned long, w1_slave_found_callback);
};
-#define W1_MASTER_NEED_EXIT 0
#define W1_MASTER_NEED_RECONNECT 1
struct w1_master
@@ -172,12 +171,11 @@
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;
Index: linux-2.6/drivers/w1/w1_int.c
===================================================================
--- linux-2.6.orig/drivers/w1/w1_int.c 2005-12-27 18:30:31.000000000 +0100
+++ linux-2.6/drivers/w1/w1_int.c 2006-02-14 18:02:26.000000000 +0100
@@ -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"
@@ -65,7 +66,6 @@
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;
@@ -76,8 +76,6 @@
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);
@@ -125,12 +123,12 @@
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;
}
@@ -147,20 +145,14 @@
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);
@@ -169,15 +161,10 @@
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",
@@ -188,7 +175,7 @@
}
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);
-
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