dm: add ->flush() dax operation support
Allow device-mapper to route flush 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 flush 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>
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 0841ec1..25e6619 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -173,6 +173,20 @@
return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
}
+static void linear_dax_flush(struct dm_target *ti, pgoff_t pgoff, void *addr,
+ size_t size)
+{
+ 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);
+ if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(size, PAGE_SIZE), &pgoff))
+ return;
+ dax_flush(dax_dev, pgoff, addr, size);
+}
+
static struct target_type linear_target = {
.name = "linear",
.version = {1, 3, 0},
@@ -186,6 +200,7 @@
.iterate_devices = linear_iterate_devices,
.direct_access = linear_dax_direct_access,
.dax_copy_from_iter = linear_dax_copy_from_iter,
+ .dax_flush = linear_dax_flush,
};
int __init dm_linear_init(void)