[RFC 00/11] DAX fsynx/msync support

Ross Zwisler
2015-10-29T20:12:33Z

This patch series adds support for fsync/msync to DAX.

Patches 1 through 8 add various utilities that the DAX code will eventually
need, and the DAX code itself is added by patch 9. Patches 10 and 11 are
filesystem changes that are needed after the DAX code is added, but these
patches may change slightly as the filesystem fault handling for DAX is
being modified ([1] and [2]).

I've marked this series as RFC because I'm still testing, but I wanted to
get this out there so people would see the direction I was going and
hopefully comment on any big red flags sooner rather than later.

I realize that we are getting pretty dang close to the v4.4 merge window,
but I think that if we can get this reviewed and working it's a much better
solution than the "big hammer" approach that blindly flushes entire PMEM
namespaces [3].

[1] http://oss.sgi.com/archives/xfs/2015-10/msg00523.html
[2] http://marc.info/?l=linux-ext4&m=144550211312472&w=2
[3] https://lists.01.org/pipermail/linux-nvdimm/2015-October/002614.html

Ross Zwisler (11):
pmem: add wb_cache_pmem() to the PMEM API
mm: add pmd_mkclean()
pmem: enable REQ_FLUSH handling
dax: support dirty DAX entries in radix tree
mm: add follow_pte_pmd()
mm: add pgoff_mkclean()
mm: add find_get_entries_tag()
fs: add get_block() to struct inode_operations
dax: add support for fsync/sync
xfs, ext2: call dax_pfn_mkwrite() on write fault
ext4: add ext4_dax_pfn_mkwrite()

arch/x86/include/asm/pgtable.h | 5 ++
arch/x86/include/asm/pmem.h | 11 +--
drivers/nvdimm/pmem.c | 3 +-
fs/dax.c | 161 +++++++++++++++++++++++++++++++++++++++--
fs/ext2/file.c | 5 +-
fs/ext4/file.c | 23 +++++-
fs/inode.c | 1 +
fs/xfs/xfs_file.c | 9 ++-
fs/xfs/xfs_iops.c | 1 +
include/linux/dax.h | 6 ++
include/linux/fs.h | 5 +-
include/linux/mm.h | 2 +
include/linux/pagemap.h | 3 +
include/linux/pmem.h | 22 +++++-
include/linux/radix-tree.h | 3 +
include/linux/rmap.h | 5 ++
mm/filemap.c | 73 ++++++++++++++++++-
mm/huge_memory.c | 14 ++--
mm/memory.c | 41 +++++++++--
mm/page-writeback.c | 9 +++
mm/rmap.c | 53 ++++++++++++++
mm/truncate.c | 5 +-
22 files changed, 418 insertions(+), 42 deletions(-)

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2.1.0