Commit 148b6f4c authored by Chen Yu's avatar Chen Yu Committed by Rafael J. Wysocki
Browse files

PM: hibernate: Fix the exclusive get block device in test_resume mode 

Commit 5904de0d ("PM: hibernate: Do not get block device exclusively
in test_resume mode") fixes a hibernation issue under test_resume mode.
That commit is supposed to open the block device in non-exclusive mode
when in test_resume. However the code does the opposite, which is against
its description.

In summary, the swap device is only opened exclusively by swsusp_check()
with its corresponding *close(), and must be in non test_resume mode.
This is to avoid the race condition that different processes scribble the
device at the same time. All the other cases should use non-exclusive mode.

Fix it by really disabling exclusive mode under test_resume.

Fixes: 5904de0d ("PM: hibernate: Do not get block device exclusively in test_resume mode")
Closes: https://lore.kernel.org/lkml/000000000000761f5f0603324129@google.com/


Reported-by: default avatarPengfei Xu <pengfei.xu@intel.com>
Signed-off-by: default avatarChen Yu <yu.c.chen@intel.com>
Tested-by: default avatarChenzhou Feng <chenzhoux.feng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 40d84e19

kernel/power/hibernate.c

+6 −6
Original line number Diff line number Diff line
@@ -786,9 +786,9 @@ int hibernate(void) 
	unlock_device_hotplug();

	if (snapshot_test) {

		pm_pr_dbg("Checking hibernation image\n");

		error = swsusp_check(snapshot_test);

		error = swsusp_check(false);

		if (!error)

			error = load_image_and_restore(snapshot_test);

			error = load_image_and_restore(false);

	}

	thaw_processes();
@@ -945,14 +945,14 @@ static int software_resume(void) 
	pm_pr_dbg("Looking for hibernation image.\n");



	mutex_lock(&system_transition_mutex);

	error = swsusp_check(false);

	error = swsusp_check(true);

	if (error)

		goto Unlock;



	/* The snapshot device should not be opened while we're running */

	if (!hibernate_acquire()) {

		error = -EBUSY;

		swsusp_close(false);

		swsusp_close(true);

		goto Unlock;

	}
@@ -973,7 +973,7 @@ static int software_resume(void) 
		goto Close_Finish;

	}



	error = load_image_and_restore(false);

	error = load_image_and_restore(true);

	thaw_processes();

 Finish:

	pm_notifier_call_chain(PM_POST_RESTORE);
@@ -987,7 +987,7 @@ static int software_resume(void) 
	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");

	return error;

 Close_Finish:

	swsusp_close(false);

	swsusp_close(true);

	goto Finish;

}