dm: teach dm-targets to use a dax_device + dax_operations

Arrange for dm to lookup the dax services available from member devices.
Update the dax-capable targets, linear and stripe, to route dax
operations to the underlying device. Changes the target-internal
->direct_access() method to more closely align with the dax_operations
->direct_access() calling convention.

Cc: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams
2017-04-12 13:37:44 -07:00
parent f26c5719b2
commit 817bf40265
6 changed files with 42 additions and 47 deletions

View File

@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/log2.h>
@@ -308,27 +309,25 @@ static int stripe_map(struct dm_target *ti, struct bio *bio)
return DM_MAPIO_REMAPPED;
}
static long stripe_direct_access(struct dm_target *ti, sector_t sector,
void **kaddr, pfn_t *pfn, long size)
static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
long nr_pages, void **kaddr, pfn_t *pfn)
{
sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
struct stripe_c *sc = ti->private;
uint32_t stripe;
struct dax_device *dax_dev;
struct block_device *bdev;
struct blk_dax_ctl dax = {
.size = size,
};
uint32_t stripe;
long ret;
stripe_map_sector(sc, sector, &stripe, &dax.sector);
dax.sector += sc->stripe[stripe].physical_start;
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_direct_access(bdev, &dax);
*kaddr = dax.addr;
*pfn = dax.pfn;
return ret;
ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
if (ret)
return ret;
return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
}
/*
@@ -448,7 +447,7 @@ static struct target_type stripe_target = {
.status = stripe_status,
.iterate_devices = stripe_iterate_devices,
.io_hints = stripe_io_hints,
.direct_access = stripe_direct_access,
.direct_access = stripe_dax_direct_access,
};
int __init dm_stripe_init(void)