Changes since v4 [1]: * Fix the changelog of "dax: introduce IS_DEVDAX() and IS_FSDAX()" to better clarify the need for new helpers (Jan) * Replace dax_sem_is_locked() with dax_sem_assert_held() (Jan) * Use file_inode() in vma_is_dax() (Jan) * Resend the full series to linux-xfs@ (Dave) * Collect Jan's Reviewed-by [1]: https://lists.01.org/pipermail/linux-nvdimm/2018-February/014271.html --- The vfio interface, like RDMA, wants to setup long term (indefinite) pins of the pages backing an address range so that a guest or userspace driver can perform DMA to the with physical address. Given that this pinning may lead to filesystem operations deadlocking in the filesystem-dax case, the pinning request needs to be rejected. The longer term fix for vfio, RDMA, and any other long term pin user, is to provide a 'pin with lease' mechanism. Similar to the leases that are hold for pNFS RDMA layouts, this userspace lease gives the kernel a way to notify userspace that the block layout of the file is changing and the kernel is revoking access to pinned pages. Related to this change is the discovery that vma_is_fsdax() was causing device-dax inode detection to fail. That lead to series of fixes and cleanups to make sure that S_DAX is defined correctly in the CONFIG_FS_DAX=n + CONFIG_DEV_DAX=y case. --- Dan Williams (12): dax: fix vma_is_fsdax() helper dax: introduce IS_DEVDAX() and IS_FSDAX() ext2, dax: finish implementing dax_sem helpers ext2, dax: define ext2_dax_*() infrastructure in all cases ext4, dax: define ext4_dax_*() infrastructure in all cases ext2, dax: replace IS_DAX() with IS_FSDAX() ext4, dax: replace IS_DAX() with IS_FSDAX() xfs, dax: replace IS_DAX() with IS_FSDAX() mm, dax: replace IS_DAX() with IS_DEVDAX() or IS_FSDAX() fs, dax: kill IS_DAX() dax: fix S_DAX definition vfio: disable filesystem-dax page pinning drivers/vfio/vfio_iommu_type1.c | 18 ++++++++++++++-- fs/ext2/ext2.h | 6 +++++ fs/ext2/file.c | 19 +++++------------ fs/ext2/inode.c | 10 ++++----- fs/ext4/file.c | 18 +++++----------- fs/ext4/inode.c | 4 ++-- fs/ext4/ioctl.c | 2 +- fs/ext4/super.c | 2 +- fs/iomap.c | 2 +- fs/xfs/xfs_file.c | 14 ++++++------- fs/xfs/xfs_ioctl.c | 4 ++-- fs/xfs/xfs_iomap.c | 6 +++-- fs/xfs/xfs_reflink.c | 2 +- include/linux/dax.h | 12 ++++++++--- include/linux/fs.h | 43 ++++++++++++++++++++++++++++----------- mm/fadvise.c | 3 ++- mm/filemap.c | 4 ++-- mm/huge_memory.c | 4 +++- mm/madvise.c | 3 ++- 19 files changed, 102 insertions(+), 74 deletions(-)