4.14-stable review patch. If anyone has any objections, please let me know.
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From: Ross Zwisler ross.zwisler@linux.intel.com
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@linux.intel.com Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support") Cc: stable@vger.kernel.org Acked-by: Dan Williams dan.j.williams@intel.com Reviewed-by: Toshi Kani toshi.kani@hpe.com Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);