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/hibernate.c b/kernel/power/hibernate.c
index 605149a6d219..6d6d28870335 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -69,14 +69,14 @@ void hibernation_set_ops(const struct platform_hibernation_ops *ops)
                 WARN_ON(1);
                 return;
         }
-        mutex_lock(&pm_mutex);
+        lock_system_sleep();
         hibernation_ops = ops;
         if (ops)
                 hibernation_mode = HIBERNATION_PLATFORM;
         else if (hibernation_mode == HIBERNATION_PLATFORM)
                 hibernation_mode = HIBERNATION_SHUTDOWN;
 
-        mutex_unlock(&pm_mutex);
+        unlock_system_sleep();
 }
 
 static bool entering_platform_hibernation;
@@ -597,7 +597,7 @@ int hibernate(void)
 {
         int error;
 
-        mutex_lock(&pm_mutex);
+        lock_system_sleep();
         /* The snapshot device should not be opened while we're running */
         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
                 error = -EBUSY;
@@ -665,7 +665,7 @@ int hibernate(void)
         pm_restore_console();
         atomic_inc(&snapshot_device_available);
  Unlock:
-        mutex_unlock(&pm_mutex);
+        unlock_system_sleep();
         return error;
 }
 
@@ -893,7 +893,7 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
         p = memchr(buf, '\n', n);
         len = p ? p - buf : n;
 
-        mutex_lock(&pm_mutex);
+        lock_system_sleep();
         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
                 if (len == strlen(hibernation_modes[i])
                     && !strncmp(buf, hibernation_modes[i], len)) {
@@ -919,7 +919,7 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
         if (!error)
                 pr_debug("PM: Hibernation mode set to '%s'\n",
                          hibernation_modes[mode]);
-        mutex_unlock(&pm_mutex);
+        unlock_system_sleep();
         return error ? error : n;
 }
 
@@ -946,9 +946,9 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
         if (maj != MAJOR(res) || min != MINOR(res))
                 goto out;
 
-        mutex_lock(&pm_mutex);
+        lock_system_sleep();
         swsusp_resume_device = res;
-        mutex_unlock(&pm_mutex);
+        unlock_system_sleep();
         printk(KERN_INFO "PM: Starting manual resume from disk\n");
         noresume = 0;
         software_resume();