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Christoph Hellwig

2021-Oct-18 04:40 UTC

[PATCH 10/11] 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: Christoph Hellwig <hch at lst.de>
---
 drivers/md/dm-stripe.c | 63 ++++++++++--------------------------------
 1 file changed, 15 insertions(+), 48 deletions(-)

diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index f084607220293..50dba3f39274c 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -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;
-
-	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_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;
+	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;
-
-	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);
 }
 
-- 
2.30.2

Dan Williams

2021-Oct-28 01:41 UTC

head link

[PATCH 10/11] dm-stripe: add a stripe_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.
Again, looks good. Kind of embarrassing when the open-coded version is
less LOC than using the helper.

Mike, ack?
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/md/dm-stripe.c | 63 ++++++++++--------------------------------
>  1 file changed, 15 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
> index f084607220293..50dba3f39274c 100644
> --- a/drivers/md/dm-stripe.c
> +++ b/drivers/md/dm-stripe.c
> @@ -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;
> -
> -       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_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;
> +       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;
> -
> -       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);
>  }
>
> --
> 2.30.2
>

Mike Snitzer

2021-Nov-01 16:21 UTC

head link

[PATCH 10/11] dm-stripe: add a stripe_dax_pgoff helper

On Wed, Oct 27 2021 at  9:41P -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.
> 
> Again, looks good. Kind of embarrassing when the open-coded version is
> less LOC than using the helper.
> 
> Mike, ack?
Acked-by: Mike Snitzer <snitzer at redhat.com>

Virtualization - Nov 2021 - [PATCH 10/11] dm-stripe: add a stripe_dax_pgoff helper

[PATCH 10/11] dm-stripe: add a stripe_dax_pgoff helper

[PATCH 10/11] dm-stripe: add a stripe_dax_pgoff helper

[PATCH 10/11] dm-stripe: add a stripe_dax_pgoff helper