commit bcda53faf5814c0c6025a0bd47108adfcbe9f199
author Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Wed Dec 07 22:29:54 2011 +0100
committer Rafael J. Wysocki <rjw@sisk.pl> Thu Dec 08 23:22:29 2011 +0100
tree a8768204a16b24436f33fac00c1bb4dcfb4fafd5
parent 9b6fc5dc879bc90f765db0e95eefcf123d0d06dd

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>

kernel/power/hibernate.c

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 605149a..6d6d288 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -69,14 +69,14 @@
 		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 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 @@
 	pm_restore_console();
 	atomic_inc(&snapshot_device_available);
  Unlock:
-	mutex_unlock(&pm_mutex);
+	unlock_system_sleep();
 	return error;
 }
 
@@ -893,7 +893,7 @@
 	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 @@
 	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 @@
 	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();