On Thu, Oct 14, 2021 at 10:39:27AM -0500, Alex Sierra wrote:

From: Ralph Campbell <redacted>

There are several places where ZONE_DEVICE struct pages assume a reference
count == 1 means the page is idle and free. Instead of open coding this,
add a helper function to hide this detail.

Signed-off-by: Ralph Campbell <redacted>
Signed-off-by: Alex Sierra <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>