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 v4: * No code changes. * Updated the changelogs for patches 1 and 3. * Removed the Cc: stable from patch 1. * Added a Fixes: tag to patch 2. 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-table.c | 7 ++++--- drivers/md/dm.c | 3 +-- drivers/nvdimm/pmem.c | 3 ++- 4 files changed, 15 insertions(+), 6 deletions(-) -- 2.14.4
