Add an explicit check for QUEUE_FLAG_DAX to __bdev_dax_supported(). This is needed for DM configurations where the first element in the dm-linear or dm-stripe target supports DAX, but other elements do not. Without this check __bdev_dax_supported() will pass for such devices, letting a filesystem on that device mount with the DAX option.

Signed-off-by: Ross Zwisler ross.zwisler@linux.intel.com Suggested-by: Mike Snitzer snitzer@redhat.com Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support") Cc: stable@vger.kernel.org --- drivers/dax/super.c | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 903d9c473749..45276abf03aa 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -86,6 +86,7 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) { struct dax_device *dax_dev; bool dax_enabled = false; + struct request_queue *q; pgoff_t pgoff; int err, id; void *kaddr; @@ -99,6 +100,13 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) return false; }

+ q = bdev_get_queue(bdev); + if (!q || !blk_queue_dax(q)) { + pr_debug("%s: error: request queue doesn't support dax\n", + bdevname(bdev, buf)); + return false; + } + err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); if (err) { pr_debug("%s: error: unaligned partition for dax\n",