[PATCH] kthread: airo.c

The airo driver is currently caching a pid for later use, but with the
implementation of containers, pids themselves do not uniquely identify a
task.  The driver is also using kernel_thread() which is deprecated in
drivers.

This patch essentially replaces the kernel_thread() with kthread_create().
It also stores the task_struct of the airo_thread rather than its pid.
Since this introduces a second task_struct in struct airo_info, the patch
renames airo_info.task to airo_info.list_bss_task.

As an extension of these changes, the patch further:

	 - replaces kill_proc() with kthread_stop()
	 - replaces signal_pending() with kthread_should_stop()
	 - removes thread completion synchronisation which is handled by
	   kthread_stop().

[akpm@osdl.org: fix races]
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Javier Achirica <achirica@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Sukadev Bhattiprolu 2006-08-14 23:12:03 -07:00 committed by John W. Linville
parent e4ac2663ea
commit 3b4c7d6403

View File

@ -47,6 +47,7 @@
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <net/ieee80211.h>
#include <linux/kthread.h>
#include "airo.h"
@ -1187,11 +1188,10 @@ struct airo_info {
int whichbap);
unsigned short *flash;
tdsRssiEntry *rssi;
struct task_struct *task;
struct task_struct *list_bss_task;
struct task_struct *airo_thread_task;
struct semaphore sem;
pid_t thr_pid;
wait_queue_head_t thr_wait;
struct completion thr_exited;
unsigned long expires;
struct {
struct sk_buff *skb;
@ -1733,12 +1733,12 @@ static int readBSSListRid(struct airo_info *ai, int first,
cmd.cmd=CMD_LISTBSS;
if (down_interruptible(&ai->sem))
return -ERESTARTSYS;
ai->list_bss_task = current;
issuecommand(ai, &cmd, &rsp);
up(&ai->sem);
/* Let the command take effect */
ai->task = current;
ssleep(3);
ai->task = NULL;
schedule_timeout_uninterruptible(3 * HZ);
ai->list_bss_task = NULL;
}
rc = PC4500_readrid(ai, first ? ai->bssListFirst : ai->bssListNext,
list, ai->bssListRidLen, 1);
@ -2400,8 +2400,7 @@ void stop_airo_card( struct net_device *dev, int freeres )
clear_bit(FLAG_REGISTERED, &ai->flags);
}
set_bit(JOB_DIE, &ai->jobs);
kill_proc(ai->thr_pid, SIGTERM, 1);
wait_for_completion(&ai->thr_exited);
kthread_stop(ai->airo_thread_task);
/*
* Clean out tx queue
@ -2811,9 +2810,8 @@ static struct net_device *_init_airo_card( unsigned short irq, int port,
ai->config.len = 0;
ai->pci = pci;
init_waitqueue_head (&ai->thr_wait);
init_completion (&ai->thr_exited);
ai->thr_pid = kernel_thread(airo_thread, dev, CLONE_FS | CLONE_FILES);
if (ai->thr_pid < 0)
ai->airo_thread_task = kthread_run(airo_thread, dev, dev->name);
if (IS_ERR(ai->airo_thread_task))
goto err_out_free;
ai->tfm = NULL;
rc = add_airo_dev( dev );
@ -2930,8 +2928,7 @@ err_out_unlink:
del_airo_dev(dev);
err_out_thr:
set_bit(JOB_DIE, &ai->jobs);
kill_proc(ai->thr_pid, SIGTERM, 1);
wait_for_completion(&ai->thr_exited);
kthread_stop(ai->airo_thread_task);
err_out_free:
free_netdev(dev);
return NULL;
@ -3063,13 +3060,7 @@ static int airo_thread(void *data) {
struct airo_info *ai = dev->priv;
int locked;
daemonize("%s", dev->name);
allow_signal(SIGTERM);
while(1) {
if (signal_pending(current))
flush_signals(current);
/* make swsusp happy with our thread */
try_to_freeze();
@ -3097,7 +3088,7 @@ static int airo_thread(void *data) {
set_bit(JOB_AUTOWEP, &ai->jobs);
break;
}
if (!signal_pending(current)) {
if (!kthread_should_stop()) {
unsigned long wake_at;
if (!ai->expires || !ai->scan_timeout) {
wake_at = max(ai->expires,
@ -3109,7 +3100,7 @@ static int airo_thread(void *data) {
schedule_timeout(wake_at - jiffies);
continue;
}
} else if (!signal_pending(current)) {
} else if (!kthread_should_stop()) {
schedule();
continue;
}
@ -3154,7 +3145,8 @@ static int airo_thread(void *data) {
else /* Shouldn't get here, but we make sure to unlock */
up(&ai->sem);
}
complete_and_exit (&ai->thr_exited, 0);
return 0;
}
static irqreturn_t airo_interrupt ( int irq, void* dev_id, struct pt_regs *regs) {
@ -3235,8 +3227,8 @@ static irqreturn_t airo_interrupt ( int irq, void* dev_id, struct pt_regs *regs)
if(newStatus == ASSOCIATED || newStatus == REASSOCIATED) {
if (auto_wep)
apriv->expires = 0;
if (apriv->task)
wake_up_process (apriv->task);
if (apriv->list_bss_task)
wake_up_process(apriv->list_bss_task);
set_bit(FLAG_UPDATE_UNI, &apriv->flags);
set_bit(FLAG_UPDATE_MULTI, &apriv->flags);