PM/hibernate: fix "swap breaks after hibernation failures"
http://bugzilla.kernel.org/show_bug.cgi?id=12239
The image writing code dropped a reference to the current swap device.
This doesn't show up if the hibernation succeeds - because it doesn't
affect the image which gets resumed. But it means multiple _failed_
hibernations end up freeing the swap device while it is still use!
swsusp_write() finds the block device for the swap file using swap_type_of().
It then uses blkdev_get() / blkdev_put() to open and close the block device.
Unfortunately, blkdev_get() assumes ownership of the inode of the block_device
passed to it. So blkdev_put() calls iput() on the inode. This is by design
and other callers expect this behaviour. The fix is for swap_type_of() to take
a reference on the inode using bdget().
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 7e6304d..312fafe 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -635,7 +635,7 @@
if (!bdev) {
if (bdev_p)
- *bdev_p = sis->bdev;
+ *bdev_p = bdget(sis->bdev->bd_dev);
spin_unlock(&swap_lock);
return i;
@@ -647,7 +647,7 @@
struct swap_extent, list);
if (se->start_block == offset) {
if (bdev_p)
- *bdev_p = sis->bdev;
+ *bdev_p = bdget(sis->bdev->bd_dev);
spin_unlock(&swap_lock);
bdput(bdev);