[PATCH 4.19 23/39] dm table: fix DAX iterate_devices based device capability checks

[gregkh]

From: Greg Kroah-Hartman <gre...@linuxfoundation.org>

From: Jeffle Xu <jeffl...@linux.alibaba.com>

commit 5b0fab508992c2e120971da658ce80027acbc405 upstream.

Fix dm_table_supports_dax() and invert logic of both
iterate_devices_callout_fn so that all devices' DAX capabilities are
properly checked.

Fixes: 545ed20e6df6 ("dm: add infrastructure for DAX support")
Cc: sta...@vger.kernel.org
Signed-off-by: Jeffle Xu <jeffl...@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snit...@redhat.com>
[jeffle: no dax synchronous]
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/md/dm-table.c |   25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -891,10 +891,10 @@ void dm_table_set_type(struct dm_table *
 }
 EXPORT_SYMBOL_GPL(dm_table_set_type);
 
-static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
+static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
                               sector_t start, sector_t len, void *data)
 {
-       return bdev_dax_supported(dev->bdev, PAGE_SIZE);
+       return !bdev_dax_supported(dev->bdev, PAGE_SIZE);
 }
 
 static bool dm_table_supports_dax(struct dm_table *t)
@@ -910,7 +910,7 @@ static bool dm_table_supports_dax(struct
                        return false;
 
                if (!ti->type->iterate_devices ||
-                   !ti->type->iterate_devices(ti, device_supports_dax, NULL))
+                   ti->type->iterate_devices(ti, device_not_dax_capable, NULL))
                        return false;
        }
 
@@ -1731,23 +1731,6 @@ static int device_dax_write_cache_enable
        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_rotational(struct dm_target *ti, struct dm_dev *dev,
                                sector_t start, sector_t len, void *data)
 {
@@ -1946,7 +1929,7 @@ void dm_table_set_restrictions(struct dm
        else
                blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
 
-       if (dm_table_supports_dax_write_cache(t))
+       if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled))
                dax_write_cache(t->md->dax_dev, true);
 
        /* Ensure that all underlying devices are non-rotational. */