[PATCH 3/3] debugging w1_therm race condition

[David Fries]

---
 drivers/w1/slaves/w1_therm.c |    4 ++++
 drivers/w1/w1.c              |    4 ++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index cb46e85..cb0fe1b 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -80,11 +80,13 @@ static int w1_therm_add_slave(struct w1_slave *sl)
 
 static void w1_therm_remove_slave(struct w1_slave *sl)
 {
+	printk(KERN_NOTICE "%s about to lock faily_data->lock\n", __func__);
 	/* Getting the lock means w1_slave_show isn't sleeping and the
 	 * family_data can be freed.
 	 */
 	mutex_lock(THERM_LOCK(sl));
 	mutex_unlock(THERM_LOCK(sl));
+	printk(KERN_NOTICE "%s unlocked faily_data->lock\n", __func__);
 	kfree(sl->family_data);
 	sl->family_data = NULL;
 }
@@ -248,7 +250,9 @@ static ssize_t w1_slave_show(struct device *device,
 				mutex_unlock(&dev->bus_mutex);
 
 				//sleep_rem = msleep_interruptible(tm);
+				printk(KERN_NOTICE "start sleep %p refcnt %u\n", sl, atomic_read(&sl->refcnt));
 				sleep_rem = msleep_interruptible(10*1000);
+				printk(KERN_NOTICE "end sleep %p refcnt %u\n", sl, atomic_read(&sl->refcnt));
 				if (sleep_rem != 0) {
 					ret = -EINTR;
 					goto post_unlock;
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 181f41c..9bb3116 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -650,8 +650,10 @@ static int w1_family_notify(unsigned long action, struct w1_slave *sl)
 	case BUS_NOTIFY_DEL_DEVICE:
 		if (fops->remove_slave)
 			sl->family->fops->remove_slave(sl);
+		printk(KERN_NOTICE "calling sysfs_remove_groups\n");
 		if (fops->groups)
 			sysfs_remove_groups(&sl->dev.kobj, fops->groups);
+		printk(KERN_NOTICE "returned sysfs_remove_groups\n");
 		break;
 	}
 	return 0;
@@ -769,6 +771,7 @@ int w1_unref_slave(struct w1_slave *sl)
 	int refcnt;
 	mutex_lock(&dev->list_mutex);
 	refcnt = atomic_sub_return(1, &sl->refcnt);
+	printk(KERN_NOTICE "%s slave %p refcnt now %u\n", __func__, sl, refcnt);
 	if (refcnt == 0) {
 		struct w1_netlink_msg msg;
 
@@ -788,6 +791,7 @@ int w1_unref_slave(struct w1_slave *sl)
 		memset(sl, 0, sizeof(*sl));
 		#endif
 		kfree(sl);
+		printk(KERN_NOTICE "%s w1_slave %p\n", __func__, sl);
 	}
 	atomic_dec(&dev->refcnt);
 	mutex_unlock(&dev->list_mutex);
-- 
1.7.10.4

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