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/dax/super.c b/drivers/dax/super.c
index dd299e5..b7729e4 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -185,6 +185,17 @@
}
EXPORT_SYMBOL_GPL(dax_copy_from_iter);
+void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+ size_t size)
+{
+ if (!dax_alive(dax_dev))
+ return;
+
+ if (dax_dev->ops->flush)
+ dax_dev->ops->flush(dax_dev, pgoff, addr, size);
+}
+EXPORT_SYMBOL_GPL(dax_flush);
+
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);
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)
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 1ef914f..8e73517 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -351,6 +351,25 @@
return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
}
+static void stripe_dax_flush(struct dm_target *ti, pgoff_t pgoff, void *addr,
+ size_t size)
+{
+ 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(size, PAGE_SIZE), &pgoff))
+ return;
+ dax_flush(dax_dev, pgoff, addr, size);
+}
+
/*
* Stripe status:
*
@@ -471,6 +490,7 @@
.io_hints = stripe_io_hints,
.direct_access = stripe_dax_direct_access,
.dax_copy_from_iter = stripe_dax_copy_from_iter,
+ .dax_flush = stripe_dax_flush,
};
int __init dm_stripe_init(void)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7faaceb..09b3efd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -994,6 +994,24 @@
return ret;
}
+static void dm_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+ size_t size)
+{
+ struct mapped_device *md = dax_get_private(dax_dev);
+ sector_t sector = pgoff * PAGE_SECTORS;
+ struct dm_target *ti;
+ int srcu_idx;
+
+ ti = dm_dax_get_live_target(md, sector, &srcu_idx);
+
+ if (!ti)
+ goto out;
+ if (ti->type->dax_flush)
+ ti->type->dax_flush(ti, pgoff, addr, size);
+ out:
+ dm_put_live_table(md, srcu_idx);
+}
+
/*
* A target may call dm_accept_partial_bio only from the map routine. It is
* allowed for all bio types except REQ_PREFLUSH.
@@ -2885,6 +2903,7 @@
static const struct dax_operations dm_dax_ops = {
.direct_access = dm_dax_direct_access,
.copy_from_iter = dm_dax_copy_from_iter,
+ .flush = dm_dax_flush,
};
/*