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

Commit 5904de0d73 ("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: 5904de0d73 ("PM: hibernate: Do not get block device exclusively in test_resume mode")
Closes: https://lore.kernel.org/lkml/000000000000761f5f0603324129@google.com/
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: Chenzhou Feng <chenzhoux.feng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Chen Yu 2023-09-06 12:18:52 +08:00 committed by Rafael J. Wysocki
parent 40d84e198b
commit 148b6f4cc3

View File

@ -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;
}