On Thu, Jun 17, 2021 at 10:16:58AM -0500, Alex Sierra wrote:
> From: Ralph Campbell <rcampbell@xxxxxxxxxx>
>
> 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.
>
> v2:
> [AS]: rename dax_layout_is_idle_page func to dax_page_unused
Did you even compile test this?
> Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
> Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
> ---
> fs/dax.c | 4 ++--
> fs/ext4/inode.c | 5 +----
> fs/xfs/xfs_file.c | 4 +---
> include/linux/dax.h | 10 ++++++++++
> 4 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index 26d5dcd2d69e..321f4ddc6643 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping,
> for_each_mapped_pfn(entry, pfn) {
> struct page *page = pfn_to_page(pfn);
>
> - WARN_ON_ONCE(trunc && page_ref_count(page) > 1);
> + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page));
Because you still use dax_layout_is_idle_page() here, not
dax_page_unused()...
> WARN_ON_ONCE(page->mapping && page->mapping != mapping);
> page->mapping = NULL;
> page->index = 0;
> @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry)
> for_each_mapped_pfn(entry, pfn) {
> struct page *page = pfn_to_page(pfn);
>
> - if (page_ref_count(page) > 1)
> + if (!dax_layout_is_idle_page(page))
Here too.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
