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From:   Chen Yu <yu.c.chen@intel.com>
To:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <len.brown@intel.com>
Cc:     Ye Bin <yebin10@huawei.com>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Pavankumar Kondeti <quic_pkondeti@quicinc.com>,
        Yifan Li <yifan2.li@intel.com>, Chen Yu <yu.c.chen@intel.com>
Subject: [PATCH v3 1/2] PM: hibernate: Turn snapshot_test into global variable
Date:   Fri, 14 Apr 2023 20:10:26 +0800
Message-Id: <5235527bde72c568fb26d268cf3091e8ce080306.1681443714.git.yu.c.chen@intel.com>
In-Reply-To: <cover.1681443714.git.yu.c.chen@intel.com>
References: <cover.1681443714.git.yu.c.chen@intel.com>
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There is need to check snapshot_test and open block device
in different mode, so as to avoid the race condition.

No functional changes intended.

Suggested-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 kernel/power/hibernate.c | 7 ++++++-
 kernel/power/power.h     | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 793c55a2becb..aa551b093c3f 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -64,6 +64,7 @@ enum {
 static int hibernation_mode = HIBERNATION_SHUTDOWN;
 
 bool freezer_test_done;
+bool snapshot_test;
 
 static const struct platform_hibernation_ops *hibernation_ops;
 
@@ -716,7 +717,6 @@ static int load_image_and_restore(void)
  */
 int hibernate(void)
 {
-	bool snapshot_test = false;
 	unsigned int sleep_flags;
 	int error;
 
@@ -744,6 +744,9 @@ int hibernate(void)
 	if (error)
 		goto Exit;
 
+	/* protected by system_transition_mutex */
+	snapshot_test = false;
+
 	lock_device_hotplug();
 	/* Allocate memory management structures */
 	error = create_basic_memory_bitmaps();
@@ -940,6 +943,8 @@ static int software_resume(void)
 	 */
 	mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 
+	snapshot_test = false;
+
 	if (swsusp_resume_device)
 		goto Check_image;
 
diff --git a/kernel/power/power.h b/kernel/power/power.h
index b4f433943209..b83c8d5e188d 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -59,6 +59,7 @@ asmlinkage int swsusp_save(void);
 
 /* kernel/power/hibernate.c */
 extern bool freezer_test_done;
+extern bool snapshot_test;
 
 extern int hibernation_snapshot(int platform_mode);
 extern int hibernation_restore(int platform_mode);
-- 
2.25.1