The patch below does not apply to the 4.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 15256f6cc4b44f2e70503758150267fd2a53c0d6 Mon Sep 17 00:00:00 2001

From: Ross Zwisler ross.zwisler@linux.intel.com Date: Tue, 26 Jun 2018 16:30:40 -0600 Subject: [PATCH] dax: check for QUEUE_FLAG_DAX in bdev_dax_supported()

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 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

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",