From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ross Zwisler Subject: [PATCH v4 3/3] dm: prevent DAX mounts if not supported Date: Tue, 26 Jun 2018 13:01:29 -0600 Message-ID: <20180626190129.18112-1-ross.zwisler@linux.intel.com> References: <20180626175932.8899-4-ross.zwisler@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <20180626175932.8899-4-ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Toshi Kani , Mike Snitzer , dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org Cc: linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: dm-devel.ids 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. Conditionally set QUEUE_FLAG_DAX on the DM device's request queue based on whether all underlying devices support DAX. Now that bdev_dax_supported() explicitly checks for this flag, 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 Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support") Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --- Changes in v4: * Set/clear QUEUE_FLAG_DAX in dm_table_set_restrictions(). (Mike) --- drivers/md/dm-table.c | 7 ++++--- drivers/md/dm.c | 3 +-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 938766794c2e..3d0e2c198f06 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -885,9 +885,7 @@ 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) @@ -1907,6 +1905,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, if (dm_table_supports_dax(t)) blk_queue_flag_set(QUEUE_FLAG_DAX, q); + else + blk_queue_flag_clear(QUEUE_FLAG_DAX, q); + if (dm_table_supports_dax_write_cache(t)) dax_write_cache(t->md->dax_dev, true); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index e65429a29c06..bef5a3f243ed 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1056,8 +1056,7 @@ static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, 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); -- 2.14.4