On Mon 04-06-18 16:12:06, Dan Williams wrote:
> In support of enabling memory_failure() handling for filesystem-dax
> mappings, set ->index to the pgoff of the page. The rmap implementation
> requires ->index to bound the search through the vma interval tree. The
> index is set and cleared at dax_associate_entry() and
> dax_disassociate_entry() time respectively.
>
> Cc: Jan Kara <jack@xxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Looks good to me. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/dax.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index aaec72ded1b6..cccf6cad1a7a 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -319,18 +319,27 @@ static unsigned long dax_radix_end_pfn(void *entry)
> for (pfn = dax_radix_pfn(entry); \
> pfn < dax_radix_end_pfn(entry); pfn++)
>
> -static void dax_associate_entry(void *entry, struct address_space *mapping)
> +/*
> + * TODO: for reflink+dax we need a way to associate a single page with
> + * multiple address_space instances at different linear_page_index()
> + * offsets.
> + */
> +static void dax_associate_entry(void *entry, struct address_space *mapping,
> + struct vm_area_struct *vma, unsigned long address)
> {
> - unsigned long pfn;
> + unsigned long size = dax_entry_size(entry), pfn, index;
> + int i = 0;
>
> if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
> return;
>
> + index = linear_page_index(vma, address & ~(size - 1));
> for_each_mapped_pfn(entry, pfn) {
> struct page *page = pfn_to_page(pfn);
>
> WARN_ON_ONCE(page->mapping);
> page->mapping = mapping;
> + page->index = index + i++;
> }
> }
>
> @@ -348,6 +357,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping,
> WARN_ON_ONCE(trunc && page_ref_count(page) > 1);
> WARN_ON_ONCE(page->mapping && page->mapping != mapping);
> page->mapping = NULL;
> + page->index = 0;
> }
> }
>
> @@ -604,7 +614,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
> new_entry = dax_radix_locked_entry(pfn, flags);
> if (dax_entry_size(entry) != dax_entry_size(new_entry)) {
> dax_disassociate_entry(entry, mapping, false);
> - dax_associate_entry(new_entry, mapping);
> + dax_associate_entry(new_entry, mapping, vmf->vma, vmf->address);
> }
>
> if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) {
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
