dm, dax: Make sure dm_dax_flush() is called if device supports it

Currently dm_dax_flush() is not being called, even if underlying dax
device supports write cache, because DAXDEV_WRITE_CACHE is not being
propagated up to the DM dax device.

If the underlying dax device supports write cache, set
DAXDEV_WRITE_CACHE on the DM dax device.  This will cause dm_dax_flush()
to be called.

Fixes: abebfbe2f7 ("dm: add ->flush() dax operation support")
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Vivek Goyal 2017-07-26 09:35:09 -04:00 committed by Mike Snitzer
parent 34c96507e8
commit 273752c9ff
3 changed files with 42 additions and 0 deletions

View file

@ -278,6 +278,12 @@ void dax_write_cache(struct dax_device *dax_dev, bool wc)
}
EXPORT_SYMBOL_GPL(dax_write_cache);
bool dax_write_cache_enabled(struct dax_device *dax_dev)
{
return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
}
EXPORT_SYMBOL_GPL(dax_write_cache_enabled);
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);

View file

@ -20,6 +20,7 @@
#include <linux/atomic.h>
#include <linux/blk-mq.h>
#include <linux/mount.h>
#include <linux/dax.h>
#define DM_MSG_PREFIX "table"
@ -1630,6 +1631,37 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
return false;
}
static int device_dax_write_cache_enabled(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
struct dax_device *dax_dev = dev->dax_dev;
if (!dax_dev)
return false;
if (dax_write_cache_enabled(dax_dev))
return true;
return false;
}
static int dm_table_supports_dax_write_cache(struct dm_table *t)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti,
device_dax_write_cache_enabled, NULL))
return true;
}
return false;
}
static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
@ -1785,6 +1817,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
}
blk_queue_write_cache(q, wc, fua);
if (dm_table_supports_dax_write_cache(t))
dax_write_cache(t->md->dax_dev, true);
/* Ensure that all underlying devices are non-rotational. */
if (dm_table_all_devices_attribute(t, device_is_nonrot))
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);

View file

@ -87,6 +87,7 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
size_t size);
void dax_write_cache(struct dax_device *dax_dev, bool wc);
bool dax_write_cache_enabled(struct dax_device *dax_dev);
/*
* We use lowest available bit in exceptional entry for locking, one bit for