[093/151] xen: improve error handling in do_suspend.

Greg KH
2009-12-17T04:05:53Z

From: Ian Campbell <ian.campbell@citrix.com>

commit 65f63384b391bf4d384327d8a7c6de9860290b5c upstream.

The existing error handling has a few issues:
- If freeze_processes() fails it exits with shutting_down = SHUTDOWN_SUSPEND.
- If dpm_suspend_noirq() fails it exits without resuming xenbus.
- If stop_machine() fails it exits without resuming xenbus or calling
dpm_resume_end().
- xs_suspend()/xs_resume() and dpm_suspend_noirq()/dpm_resume_noirq() were not
nested in the obvious way.

Fix by ensuring each failure case goto's the correct label. Treat a failure of
stop_machine() as a cancelled suspend in order to follow the correct resume
path.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/xen/manage.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -86,32 +86,32 @@ static void do_suspend(void)
err = freeze_processes();
if (err) {
printk(KERN_ERR "xen suspend: freeze failed %d\n", err);
- return;
+ goto out;
}
#endif

err = dpm_suspend_start(PMSG_SUSPEND);
if (err) {
printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err);
- goto out;
+ goto out_thaw;
}

- printk(KERN_DEBUG "suspending xenstore...\n");
- xs_suspend();
-
err = dpm_suspend_noirq(PMSG_SUSPEND);
if (err) {
printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err);
- goto resume_devices;
+ goto out_resume;
}

+ printk(KERN_DEBUG "suspending xenstore...\n");
+ xs_suspend();
+
err = stop_machine(xen_suspend, &cancelled, cpumask_of(0));

dpm_resume_noirq(PMSG_RESUME);

if (err) {
printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
- goto out;
+ cancelled = 1;
}

if (!cancelled) {
@@ -120,15 +120,17 @@ static void do_suspend(void)
} else
xs_suspend_cancel();

-resume_devices:
+out_resume:
dpm_resume_end(PMSG_RESUME);

/* Make sure timer events get retriggered on all CPUs */
clock_was_set();
-out:
+
+out_thaw:
#ifdef CONFIG_PREEMPT
thaw_processes();
#endif
+out:
shutting_down = SHUTDOWN_INVALID;
}
#endif /* CONFIG_PM_SLEEP */