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Christoph Hellwig

2021-Oct-18 04:40 UTC

[PATCH 08/11] dm-linear: add a linear_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: Christoph Hellwig <hch at lst.de>
---
 drivers/md/dm-linear.c | 49 +++++++++++++-----------------------------
 1 file changed, 15 insertions(+), 34 deletions(-)

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 32fbab11bf90c..bf03f73fd0f36 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -164,63 +164,44 @@ static int linear_iterate_devices(struct dm_target *ti,
 }
 
 #if IS_ENABLED(CONFIG_FS_DAX)
+static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t
*pgoff)
+{
+	struct linear_c *lc = ti->private;
+	sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT);
+
+	*pgoff = (get_start_sect(lc->dev->bdev) + sector) >>
PAGE_SECTORS_SHIFT;
+	return lc->dev->dax_dev;
+}
+
 static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 		long nr_pages, void **kaddr, pfn_t *pfn)
 {
-	long ret;
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-
-	dev_sector = linear_map_sector(ti, sector);
-	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
-	if (ret)
-		return ret;
+	struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
+
 	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
 }
 
 static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+	struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
 
-	dev_sector = linear_map_sector(ti, sector);
-	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 linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+	struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
 
-	dev_sector = linear_map_sector(ti, sector);
-	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 linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
 				      size_t nr_pages)
 {
-	int ret;
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-
-	dev_sector = linear_map_sector(ti, sector);
-	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT,
&pgoff);
-	if (ret)
-		return ret;
+	struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
+
 	return dax_zero_page_range(dax_dev, pgoff, nr_pages);
 }
 
-- 
2.30.2

Dan Williams

2021-Oct-28 01:32 UTC

head link

[PATCH 08/11] dm-linear: add a linear_dax_pgoff helper

On Sun, Oct 17, 2021 at 9:41 PM Christoph Hellwig <hch at lst.de>
wrote:>
> 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.
Looks good.

Mike, ack?
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/md/dm-linear.c | 49 +++++++++++++-----------------------------
>  1 file changed, 15 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
> index 32fbab11bf90c..bf03f73fd0f36 100644
> --- a/drivers/md/dm-linear.c
> +++ b/drivers/md/dm-linear.c
> @@ -164,63 +164,44 @@ static int linear_iterate_devices(struct dm_target
*ti,
>  }
>
>  #if IS_ENABLED(CONFIG_FS_DAX)
> +static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t
*pgoff)
> +{
> +       struct linear_c *lc = ti->private;
> +       sector_t sector = linear_map_sector(ti, *pgoff <<
PAGE_SECTORS_SHIFT);
> +
> +       *pgoff = (get_start_sect(lc->dev->bdev) + sector) >>
PAGE_SECTORS_SHIFT;
> +       return lc->dev->dax_dev;
> +}
> +
>  static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
>                 long nr_pages, void **kaddr, pfn_t *pfn)
>  {
> -       long ret;
> -       struct linear_c *lc = ti->private;
> -       struct block_device *bdev = lc->dev->bdev;
> -       struct dax_device *dax_dev = lc->dev->dax_dev;
> -       sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
> -
> -       dev_sector = linear_map_sector(ti, sector);
> -       ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE,
&pgoff);
> -       if (ret)
> -               return ret;
> +       struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
> +
>         return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
>  }
>
>  static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t
pgoff,
>                 void *addr, size_t bytes, struct iov_iter *i)
>  {
> -       struct linear_c *lc = ti->private;
> -       struct block_device *bdev = lc->dev->bdev;
> -       struct dax_device *dax_dev = lc->dev->dax_dev;
> -       sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
> +       struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
>
> -       dev_sector = linear_map_sector(ti, sector);
> -       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 linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
>                 void *addr, size_t bytes, struct iov_iter *i)
>  {
> -       struct linear_c *lc = ti->private;
> -       struct block_device *bdev = lc->dev->bdev;
> -       struct dax_device *dax_dev = lc->dev->dax_dev;
> -       sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
> +       struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
>
> -       dev_sector = linear_map_sector(ti, sector);
> -       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 linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
>                                       size_t nr_pages)
>  {
> -       int ret;
> -       struct linear_c *lc = ti->private;
> -       struct block_device *bdev = lc->dev->bdev;
> -       struct dax_device *dax_dev = lc->dev->dax_dev;
> -       sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
> -
> -       dev_sector = linear_map_sector(ti, sector);
> -       ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages <<
PAGE_SHIFT, &pgoff);
> -       if (ret)
> -               return ret;
> +       struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
> +
>         return dax_zero_page_range(dax_dev, pgoff, nr_pages);
>  }
>
> --
> 2.30.2
>

Mike Snitzer

2021-Nov-01 16:18 UTC

head link

[PATCH 08/11] dm-linear: add a linear_dax_pgoff helper

On Wed, Oct 27 2021 at  9:32P -0400,
Dan Williams <dan.j.williams at intel.com> wrote:
> On Sun, Oct 17, 2021 at 9:41 PM Christoph Hellwig <hch at lst.de>
wrote:
> >
> > 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.
> 
> Looks good.
> 
> Mike, ack?
Acked-by: Mike Snitzer <snitzer at redhat.com>

Virtualization - Nov 2021 - [PATCH 08/11] dm-linear: add a linear_dax_pgoff helper

[PATCH 08/11] dm-linear: add a linear_dax_pgoff helper

[PATCH 08/11] dm-linear: add a linear_dax_pgoff helper

[PATCH 08/11] dm-linear: add a linear_dax_pgoff helper