Right now, dm_dax_flush() is not being called and I think it is not being called becuase DAXDEV_WRITE_CACHE is not set on dm dax device.
If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on dm dax device. This will get dm_dax_flush() being called. Signed-off-by: Vivek Goyal <[email protected]> --- drivers/dax/super.c | 5 +++++ drivers/md/dm-table.c | 33 +++++++++++++++++++++++++++++++++ include/linux/dax.h | 1 + 3 files changed, 39 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index ce9e563e6e1d..5c5e7b9f6831 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -278,6 +278,11 @@ 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); +} + bool dax_alive(struct dax_device *dax_dev) { lockdep_assert_held(&dax_srcu); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index a39bcd9b982a..3be0ab2a71c8 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -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 +1631,35 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush) return false; } +static int device_dax_flush_capable(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_flush(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_flush_capable, 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 +1815,9 @@ 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_flush(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); diff --git a/include/linux/dax.h b/include/linux/dax.h index 794811875732..df97b7af7e2c 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -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 -- 2.13.3 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
