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 06ea33df8560..98ade217da6c 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;
 }