4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
commit dbc626597c39b24cefce09fbd8e9dea85869a801 upstream.
Currently device_supports_dax() just checks to see if the QUEUE_FLAG_DAX
flag is set on the device's request queue to decide whether or not the
device supports filesystem DAX. Really we should be using
bdev_dax_supported() like filesystems do at mount time. This performs
other tests like checking to make sure the dax_direct_access() path works.
We also explicitly clear QUEUE_FLAG_DAX on the DM device's request queue if
any of the underlying devices do not support DAX. This makes the handling
of QUEUE_FLAG_DAX consistent with the setting/clearing of most other flags
in dm_table_set_restrictions().
Now that bdev_dax_supported() explicitly checks for QUEUE_FLAG_DAX, this
will ensure that filesystems built upon DM devices will only be able to
mount with DAX if all underlying devices also support DAX.
Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support")
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Reviewed-by: Toshi Kani <toshi.kani@xxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-table.c | 7 ++++---
drivers/md/dm.c | 3 +--
2 files changed, 5 insertions(+), 5 deletions(-)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -883,9 +883,7 @@ EXPORT_SYMBOL_GPL(dm_table_set_type);
static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
- struct request_queue *q = bdev_get_queue(dev->bdev);
-
- return q && blk_queue_dax(q);
+ return bdev_dax_supported(dev->bdev, PAGE_SIZE);
}
static bool dm_table_supports_dax(struct dm_table *t)
@@ -1815,6 +1813,9 @@ void dm_table_set_restrictions(struct dm
if (dm_table_supports_dax(t))
queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
+ else
+ queue_flag_clear_unlocked(QUEUE_FLAG_DAX, q);
+
if (dm_table_supports_dax_write_cache(t))
dax_write_cache(t->md->dax_dev, true);
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -961,8 +961,7 @@ static long dm_dax_direct_access(struct
if (len < 1)
goto out;
nr_pages = min(len, nr_pages);
- if (ti->type->direct_access)
- ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
+ ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
out:
dm_put_live_table(md, srcu_idx);
