[07/35] PM: Free memory bitmaps if opening /dev/snapshot fails

From: Greg KH
Date: Sat Jul 09 2011 - 01:58:28 EST


2.6.32-longterm review patch. If anyone has any objections, please let us know.

------------------

From: Michal Kubecek <mkubecek@xxxxxxx>

commit 8440f4b19494467883f8541b7aa28c7bbf6ac92b upstream.

When opening /dev/snapshot device, snapshot_open() creates memory
bitmaps which are freed in snapshot_release(). But if any of the
callbacks called by pm_notifier_call_chain() returns NOTIFY_BAD, open()
fails, snapshot_release() is never called and bitmaps are not freed.
Next attempt to open /dev/snapshot then triggers BUG_ON() check in
create_basic_memory_bitmaps(). This happens e.g. when vmwatchdog module
is active on s390x.

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
kernel/power/user.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -113,8 +113,10 @@ static int snapshot_open(struct inode *i
if (error)
pm_notifier_call_chain(PM_POST_RESTORE);
}
- if (error)
+ if (error) {
+ free_basic_memory_bitmaps();
atomic_inc(&snapshot_device_available);
+ }
data->frozen = 0;
data->ready = 0;
data->platform_support = 0;


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