PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()

Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock()
on 'pm_mutex', since the latter could lead to freezing failures. Hence convert
all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs
instead.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 8 insertions, 8 deletions

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 06ea33d..98ade21 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -71,7 +71,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	struct snapshot_data *data;
 	int error;
 
-	mutex_lock(&pm_mutex);
+	lock_system_sleep();
 
 	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 		error = -EBUSY;
@@ -123,7 +123,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	data->platform_support = 0;
 
  Unlock:
-	mutex_unlock(&pm_mutex);
+	unlock_system_sleep();
 
 	return error;
 }
@@ -132,7 +132,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 {
 	struct snapshot_data *data;
 
-	mutex_lock(&pm_mutex);
+	lock_system_sleep();
 
 	swsusp_free();
 	free_basic_memory_bitmaps();
@@ -146,7 +146,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 			PM_POST_HIBERNATION : PM_POST_RESTORE);
 	atomic_inc(&snapshot_device_available);
 
-	mutex_unlock(&pm_mutex);
+	unlock_system_sleep();
 
 	return 0;
 }
@@ -158,7 +158,7 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
 	ssize_t res;
 	loff_t pg_offp = *offp & ~PAGE_MASK;
 
-	mutex_lock(&pm_mutex);
+	lock_system_sleep();
 
 	data = filp->private_data;
 	if (!data->ready) {
@@ -179,7 +179,7 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
 		*offp += res;
 
  Unlock:
-	mutex_unlock(&pm_mutex);
+	unlock_system_sleep();
 
 	return res;
 }
@@ -191,7 +191,7 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
 	ssize_t res;
 	loff_t pg_offp = *offp & ~PAGE_MASK;
 
-	mutex_lock(&pm_mutex);
+	lock_system_sleep();
 
 	data = filp->private_data;
 
@@ -208,7 +208,7 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
 	if (res > 0)
 		*offp += res;
 unlock:
-	mutex_unlock(&pm_mutex);
+	unlock_system_sleep();
 
 	return res;
 }