From 273752c9ff03eb83856601b2a3458218bb949e46 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 26 Jul 2017 09:35:09 -0400 Subject: [PATCH] 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 Acked-by: Dan Williams Signed-off-by: Mike Snitzer --- drivers/dax/super.c | 6 ++++++ drivers/md/dm-table.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/dax.h | 1 + 3 files changed, 42 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index ce9e563e6e1d..938eb4868f7f 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -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); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index a39bcd9b982a..28a4071cdf85 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -20,6 +20,7 @@ #include #include #include +#include #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); 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 -- 2.39.2