No code changes from v1. Just CCing the xfs mailing list & adding one Reviewed-by from Darrick. --- 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. * In DM you can't transition a dm target which could possibly support DAX (mode DM_TYPE_DAX_BIO_BASED) to one which can't support DAX (mode DM_TYPE_BIO_BASED), even if you never use DAX. The first 2 patches in this series are prep work from Darrick and Dave which improve bdev_dax_supported(). The last 5 problems fix the above mentioned problems in DM. I feel that this series simplifies the handling of DAX devices in DM, and the last 5 DM-related patches have a net code reduction of 50 lines. Darrick J. Wong (1): fs: allow per-device dax status checking for filesystems Dave Jiang (1): dax: change bdev_dax_supported() to support boolean returns Ross Zwisler (5): dm: fix test for DAX device support dm: prevent DAX mounts if not supported dm: remove DM_TYPE_DAX_BIO_BASED dm_queue_mode dm-snap: remove unnecessary direct_access() stub dm-error: remove unnecessary direct_access() stub drivers/dax/super.c | 44 +++++++++++++++++++++---------------------- drivers/md/dm-ioctl.c | 16 ++++++---------- drivers/md/dm-snap.c | 8 -------- drivers/md/dm-table.c | 29 +++++++++++----------------- drivers/md/dm-target.c | 7 ------- drivers/md/dm.c | 7 ++----- fs/ext2/super.c | 3 +-- fs/ext4/super.c | 3 +-- fs/xfs/xfs_ioctl.c | 3 ++- fs/xfs/xfs_iops.c | 30 ++++++++++++++++++++++++----- fs/xfs/xfs_super.c | 10 ++++++++-- include/linux/dax.h | 12 ++++-------- include/linux/device-mapper.h | 8 ++++++-- 13 files changed, 88 insertions(+), 92 deletions(-) -- 2.14.3
