Commit 2a68553e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Dan Williams
Browse files

dm-stripe: add a stripe_dax_pgoff helper 



Add a helper to perform the entire remapping for DAX accesses.  This
helper open codes bdev_dax_pgoff given that the alignment checks have
already been done by the submitting file system and don't need to be
repeated.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20211129102203.2243509-12-hch@lst.de


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent d19bd675

drivers/md/dm-stripe.c

+15 −48
Original line number Diff line number Diff line
@@ -301,83 +301,50 @@ static int stripe_map(struct dm_target *ti, struct bio *bio) 
}



#if IS_ENABLED(CONFIG_FS_DAX)

static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

static struct dax_device *stripe_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)

{

	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	struct stripe_c *sc = ti->private;

	struct dax_device *dax_dev;

	struct block_device *bdev;

	sector_t dev_sector;

	uint32_t stripe;

	long ret;



	stripe_map_sector(sc, sector, &stripe, &dev_sector);

	stripe_map_sector(sc, *pgoff * PAGE_SECTORS, &stripe, &dev_sector);

	dev_sector += sc->stripe[stripe].physical_start;

	dax_dev = sc->stripe[stripe].dev->dax_dev;

	bdev = sc->stripe[stripe].dev->bdev;



	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);

	if (ret)

		return ret;

	*pgoff = (get_start_sect(bdev) + dev_sector) >> PAGE_SECTORS_SHIFT;

	return sc->stripe[stripe].dev->dax_dev;

}



static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);



	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);

}



static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,

		void *addr, size_t bytes, struct iov_iter *i)

{

	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	struct stripe_c *sc = ti->private;

	struct dax_device *dax_dev;

	struct block_device *bdev;

	uint32_t stripe;

	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);



	stripe_map_sector(sc, sector, &stripe, &dev_sector);

	dev_sector += sc->stripe[stripe].physical_start;

	dax_dev = sc->stripe[stripe].dev->dax_dev;

	bdev = sc->stripe[stripe].dev->bdev;



	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))

		return 0;

	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);

}



static size_t stripe_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,

		void *addr, size_t bytes, struct iov_iter *i)

{

	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	struct stripe_c *sc = ti->private;

	struct dax_device *dax_dev;

	struct block_device *bdev;

	uint32_t stripe;



	stripe_map_sector(sc, sector, &stripe, &dev_sector);

	dev_sector += sc->stripe[stripe].physical_start;

	dax_dev = sc->stripe[stripe].dev->dax_dev;

	bdev = sc->stripe[stripe].dev->bdev;

	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);



	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))

		return 0;

	return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);

}



static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,

				      size_t nr_pages)

{

	int ret;

	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	struct stripe_c *sc = ti->private;

	struct dax_device *dax_dev;

	struct block_device *bdev;

	uint32_t stripe;



	stripe_map_sector(sc, sector, &stripe, &dev_sector);

	dev_sector += sc->stripe[stripe].physical_start;

	dax_dev = sc->stripe[stripe].dev->dax_dev;

	bdev = sc->stripe[stripe].dev->bdev;

	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);



	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);

	if (ret)

		return ret;

	return dax_zero_page_range(dax_dev, pgoff, nr_pages);

}