[04/24] PM: hibernate: move finding the resume device out of software_resume

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 78696aa04f5ca3..45e24b02cd50b6 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -907,7 +907,7 @@  int hibernate_quiet_exec(int (*func)(void *data), void *data)
 }
 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 
-static int find_resume_device(void)
+static int __init find_resume_device(void)
 {
 	if (!strlen(resume_file))
 		return -ENOENT;
@@ -942,53 +942,16 @@  static int find_resume_device(void)
 	return 0;
 }
 
-/**
- * software_resume - Resume from a saved hibernation image.
- *
- * This routine is called as a late initcall, when all devices have been
- * discovered and initialized already.
- *
- * The image reading code is called to see if there is a hibernation image
- * available for reading.  If that is the case, devices are quiesced and the
- * contents of memory is restored from the saved image.
- *
- * If this is successful, control reappears in the restored target kernel in
- * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
- * attempts to recover gracefully and make the kernel return to the normal mode
- * of operation.
- */
 static int software_resume(void)
 {
 	int error;
 
-	/*
-	 * If the user said "noresume".. bail out early.
-	 */
-	if (noresume || !hibernation_available())
-		return 0;
-
-	/*
-	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
-	 * is configured into the kernel. Since the regular hibernate
-	 * trigger path is via sysfs which takes a buffer mutex before
-	 * calling hibernate functions (which take system_transition_mutex)
-	 * this can cause lockdep to complain about a possible ABBA deadlock
-	 * which cannot happen since we're in the boot code here and
-	 * sysfs can't be invoked yet. Therefore, we use a subclass
-	 * here to avoid lockdep complaining.
-	 */
-	mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
-
-	if (!swsusp_resume_device) {
-		error = find_resume_device();
-		if (error)
-			goto Unlock;
-	}
-
 	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 
 	pm_pr_dbg("Looking for hibernation image.\n");
+
+	mutex_lock(&system_transition_mutex);
 	error = swsusp_check(false);
 	if (error)
 		goto Unlock;
@@ -1035,7 +998,39 @@  static int software_resume(void)
 	goto Finish;
 }
 
-late_initcall_sync(software_resume);
+/**
+ * software_resume_initcall - Resume from a saved hibernation image.
+ *
+ * This routine is called as a late initcall, when all devices have been
+ * discovered and initialized already.
+ *
+ * The image reading code is called to see if there is a hibernation image
+ * available for reading.  If that is the case, devices are quiesced and the
+ * contents of memory is restored from the saved image.
+ *
+ * If this is successful, control reappears in the restored target kernel in
+ * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
+ * attempts to recover gracefully and make the kernel return to the normal mode
+ * of operation.
+ */
+static int __init software_resume_initcall(void)
+{
+	/*
+	 * If the user said "noresume".. bail out early.
+	 */
+	if (noresume || !hibernation_available())
+		return 0;
+
+	if (!swsusp_resume_device) {
+		int error = find_resume_device();
+
+		if (error)
+			return error;
+	}
+
+	return software_resume();
+}
+late_initcall_sync(software_resume_initcall);
 
 
 static const char * const hibernation_modes[] = {
@@ -1176,6 +1171,9 @@  static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
 	char *name;
 	dev_t res;
 
+	if (!hibernation_available())
+		return 0;
+
 	if (len && buf[len-1] == '\n')
 		len--;
 	name = kstrndup(buf, len, GFP_KERNEL);