From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ross Zwisler Subject: [PATCH v3 0/3] Fix DM DAX handling Date: Tue, 26 Jun 2018 11:59:29 -0600 Message-ID: <20180626175932.8899-1-ross.zwisler@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: 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-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org List-Id: dm-devel.ids This series fixes a few issues that I found with DM's handling of DAX devices. Here are some of the issues I found: * We can create a dm-stripe or dm-linear device which is made up of an fsdax PMEM namespace and a raw PMEM namespace but which can hold a filesystem mounted with the -o dax mount option. DAX operations to the raw PMEM namespace part lack struct page and can fail in interesting/unexpected ways when doing things like fork(), examining memory with gdb, etc. * We can create a dm-stripe or dm-linear device which is made up of an fsdax PMEM namespace and a BRD ramdisk which can hold a filesystem mounted with the -o dax mount option. All I/O to this filesystem will fail. --- Changes since v2: * Only set QUEUE_FLAG_DAX for fsdax mode PMEM namespaces. (Mike) * Check for QUEUE_FLAG_DAX in __bdev_dax_supported(). (Mike) * Get rid of DM_TYPE_DAX_BIO_BASED reworks. (Mike) * Dropped the first 2 prep patches of v2 since they were merged for v4.18-rc1. (Thanks, Darrick!) --- Mike, can you take this series through your tree? Personally I think this should be treated as a bug fix and merged in the v4.18-rc* series. Ross Zwisler (3): pmem: only set QUEUE_FLAG_DAX for fsdax mode dax: bdev_dax_supported() check for QUEUE_FLAG_DAX dm: prevent DAX mounts if not supported drivers/dax/super.c | 8 ++++++++ drivers/md/dm-ioctl.c | 5 +++++ drivers/md/dm-table.c | 7 +++---- drivers/md/dm.c | 3 +-- drivers/nvdimm/pmem.c | 3 ++- include/linux/device-mapper.h | 5 +++++ 6 files changed, 24 insertions(+), 7 deletions(-) -- 2.14.4