[PATCH v3 11/11] PM / hibernate: update the resume offset on SNAPSHOT_SET_SWAP_AREA

[Anchal Agarwal <anchalag@amazon.com>]

From: Aleksei Besogonov <cyberax@amazon.com>

The SNAPSHOT_SET_SWAP_AREA is supposed to be used to set the hibernation
offset on a running kernel to enable hibernating to a swap file.
However, it doesn't actually update the swsusp_resume_block variable. As
a result, the hibernation fails at the last step (after all the data is
written out) in the validation of the swap signature in
mark_swapfiles().

Before this patch, the command line processing was the only place where
swsusp_resume_block was set.
[Anchal Agarwal: Changelog: Resolved patch conflict as code fragmented to
snapshot_set_swap_area]
Signed-off-by: Aleksei Besogonov <cyberax@amazon.com>
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Anchal Agarwal <anchalag@amazon.com>
---
 kernel/power/user.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/power/user.c b/kernel/power/user.c
index d5eedc2baa2a..704a7173e99c 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -242,9 +242,12 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
 		return -EINVAL;
 	}
 	data->swap = swap_type_of(swdev, offset, &bdev);
-	if (data->swap < 0)
+	if (data->swap < 0) {
 		return -ENODEV;
-
+	} else {
+		swsusp_resume_device = swdev;
+		swsusp_resume_block = offset;
+	}
 	data->bd_inode = bdev->bd_inode;
 	bdput(bdev);
 	return 0;
-- 
2.16.6