On Sat, Dec 23, 2017 at 04:56:38PM -0800, Dan Williams wrote:
> In preparation for examining the busy state of dax pages in the truncate
> path, switch from sectors to pfns in the radix.
>
> Cc: Jan Kara <jack@xxxxxxx>
> Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
> 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>
> ---
> drivers/dax/super.c | 15 ++++++++--
> fs/dax.c | 75 ++++++++++++++++++---------------------------------
> 2 files changed, 39 insertions(+), 51 deletions(-)
<>
> @@ -688,7 +685,7 @@ static int dax_writeback_one(struct block_device *bdev,
> * compare sectors as we must not bail out due to difference in lockbit
> * or entry type.
> */
Can you please also fix the comment above this test so it talks about pfns
instead of sectors?
> - if (dax_radix_sector(entry2) != dax_radix_sector(entry))
> + if (dax_radix_pfn(entry2) != dax_radix_pfn(entry))
> goto put_unlocked;
> if (WARN_ON_ONCE(dax_is_empty_entry(entry) ||
> dax_is_zero_entry(entry))) {
> @@ -718,29 +715,11 @@ static int dax_writeback_one(struct block_device *bdev,
> * 'entry'. This allows us to flush for PMD_SIZE and not have to
> * worry about partial PMD writebacks.
> */
Ditto for this comment ^^^
> - sector = dax_radix_sector(entry);
> + pfn = dax_radix_pfn(entry);
> size = PAGE_SIZE << dax_radix_order(entry);
>
> - id = dax_read_lock();
> - ret = bdev_dax_pgoff(bdev, sector, size, &pgoff);
> - if (ret)
> - goto dax_unlock;
> -
> - /*
> - * dax_direct_access() may sleep, so cannot hold tree_lock over
> - * its invocation.
> - */
> - ret = dax_direct_access(dax_dev, pgoff, size / PAGE_SIZE, &kaddr, &pfn);
> - if (ret < 0)
> - goto dax_unlock;
> -
> - if (WARN_ON_ONCE(ret < size / PAGE_SIZE)) {
> - ret = -EIO;
> - goto dax_unlock;
> - }
> -
> - dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(pfn));
> - dax_flush(dax_dev, kaddr, size);
> + dax_mapping_entry_mkclean(mapping, index, pfn);
> + dax_flush(dax_dev, page_address(pfn_to_page(pfn)), size);
> /*
> * After we have flushed the cache, we can clear the dirty tag. There
> * cannot be new dirty data in the pfn after the flush has completed as
