4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> commit 15256f6cc4b44f2e70503758150267fd2a53c0d6 upstream. 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@xxxxxxxxxxxxxxx> Suggested-by: Mike Snitzer <snitzer@xxxxxxxxxx> 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/dax/super.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -84,6 +84,7 @@ EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); bool __bdev_dax_supported(struct block_device *bdev, int blocksize) { struct dax_device *dax_dev; + struct request_queue *q; pgoff_t pgoff; int err, id; void *kaddr; @@ -96,6 +97,13 @@ bool __bdev_dax_supported(struct block_d bdevname(bdev, buf)); 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) {