[PATCH v2 11/11] PM / hibernate: update the resume offset on SNAPSHOT_SET_SWAP_AREA

[Anchal Agarwal <anchalag@xxxxxxxxxx>]

From: Aleksei Besogonov <cyberax@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Munehisa Kamata <kamatam@xxxxxxxxxx>
Signed-off-by: Anchal Agarwal <anchalag@xxxxxxxxxx>
---
 kernel/power/user.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/power/user.c b/kernel/power/user.c
index d5eedc2baa2a..e1209cefc103 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -242,8 +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);
-- 
2.20.1