Linux swapfiles use bmap which has no ability to tell the swap code
that the blocks its reporting aren't actually on the data device.
Therefore, swapon on a realtime file could corrupt random blocks on
the data device, so we must ensure that swapon cannot happen.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eryu Guan <eguan@redhat.com>
Darrick J. Wong