[PATCH 4.14 08/20] dm table: fix DAX iterate_devices based device capability checks

gregkh
2021-03-10T13:28:54Z

From: Jeffle Xu <jefflexu@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: stable@vger.kernel.org
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
[jeffle: no dax synchronous]
Signed-off-by: Greg Kroah-Hartman <gregkh@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
@@ -889,10 +889,10 @@ 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)
@@ -908,7 +908,7 @@ 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;
}

@@ -1690,23 +1690,6 @@ 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)
{
@@ -1854,7 +1837,7 @@ void dm_table_set_restrictions(struct dm
else
queue_flag_clear_unlocked(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. */