diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2017-05-29 22:57:56 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2017-06-09 19:22:21 +0300 |
| commit | 7e026c8c0a4200da86bc51edeaad79dcdccf78ca (patch) | |
| tree | b1e30796161a6b1696ce75c2098d2fb980cb6a44 /drivers/md/dm-stripe.c | |
| parent | 0aed55af88345b5d673240f90e671d79662fb01e (diff) | |
| download | linux-7e026c8c0a4200da86bc51edeaad79dcdccf78ca.tar.xz | |
dm: add ->copy_from_iter() dax operation support
Allow device-mapper to route copy_from_iter operations to the
per-target implementation. In order for the device stacking to work we
need a dax_dev and a pgoff relative to that device. This gives each
layer of the stack the information it needs to look up the operation
pointer for the next level.
This conceptually allows for an array of mixed device drivers with
varying copy_from_iter implementations.
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/md/dm-stripe.c')
| -rw-r--r-- | drivers/md/dm-stripe.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index 75152482f3ad..1ef914f9ca72 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -332,6 +332,25 @@ static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t 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; + + 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); +} + /* * Stripe status: * @@ -451,6 +470,7 @@ static struct target_type stripe_target = { .iterate_devices = stripe_iterate_devices, .io_hints = stripe_io_hints, .direct_access = stripe_dax_direct_access, + .dax_copy_from_iter = stripe_dax_copy_from_iter, }; int __init dm_stripe_init(void) |