[PATCH v9 00/22] Support ext4 on NV-DIMMs

From: Matthew Wilcox
Date: Fri Aug 01 2014 - 09:33:12 EST


From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>

One of the primary uses for NV-DIMMs is to expose them as a block device
and use a filesystem to store files on the NV-DIMM. While that works,
it currently wastes memory and CPU time buffering the files in the page
cache. We have support in ext2 for bypassing the page cache, but it
has some races which are unfixable in the current design. This series
of patches rewrite the underlying support, and add support for direct
access to ext4.

This iteration of the patchset rebases to 3.16-rc7 and makes substantial
changes based on feedback from Jan Kara, Boaz Harrosh and Kirill Shutemov:

- Fixes a double-unlock on i_mmap_mutex
- Switch the order of calling delete_from_page_cache() and
unmap_mapping_range() to match the truncate path
- Make dax_mkwrite a macro (Kirill)
- Drop vm_replace_mixed(); instead call unmap_mapping_range() before calling
vm_insert_mixed() (Kirill)
- Avoid lock inversion between i_mmap_mutex and transaction start (Jan)
- Move alignment & length checks into bdev_direct_access() (Boaz)
- Fix bugs in COW code; unfortunately this means reintroducing the knowledge
that the i_mmap_mutex protects PFNs to the core MM code.

Jan Kara (1):
ext4: Avoid lock inversion between i_mmap_mutex and transaction start

Matthew Wilcox (20):
axonram: Fix bug in direct_access
Change direct_access calling convention
Fix XIP fault vs truncate race
Allow page fault handlers to perform the COW
Introduce IS_DAX(inode)
Add copy_to_iter(), copy_from_iter() and iov_iter_zero()
Replace XIP read and write with DAX I/O
Replace ext2_clear_xip_target with dax_clear_blocks
Replace the XIP page fault handler with the DAX page fault handler
Replace xip_truncate_page with dax_truncate_page
Replace XIP documentation with DAX documentation
Remove get_xip_mem
ext2: Remove ext2_xip_verify_sb()
ext2: Remove ext2_use_xip
ext2: Remove xip.c and xip.h
Remove CONFIG_EXT2_FS_XIP and rename CONFIG_FS_XIP to CONFIG_FS_DAX
ext2: Remove ext2_aops_xip
Get rid of most mentions of XIP in ext2
xip: Add xip_zero_page_range
brd: Rename XIP to DAX

Ross Zwisler (1):
ext4: Add DAX functionality

Documentation/filesystems/Locking | 3 -
Documentation/filesystems/dax.txt | 91 +++++++
Documentation/filesystems/ext4.txt | 2 +
Documentation/filesystems/xip.txt | 68 ------
arch/powerpc/sysdev/axonram.c | 19 +-
drivers/block/Kconfig | 13 +-
drivers/block/brd.c | 26 +-
drivers/s390/block/dcssblk.c | 21 +-
fs/Kconfig | 21 +-
fs/Makefile | 1 +
fs/block_dev.c | 34 +++
fs/dax.c | 476 ++++++++++++++++++++++++++++++++++++
fs/exofs/inode.c | 1 -
fs/ext2/Kconfig | 11 -
fs/ext2/Makefile | 1 -
fs/ext2/ext2.h | 10 +-
fs/ext2/file.c | 45 +++-
fs/ext2/inode.c | 38 +--
fs/ext2/namei.c | 13 +-
fs/ext2/super.c | 53 ++--
fs/ext2/xip.c | 91 -------
fs/ext2/xip.h | 26 --
fs/ext4/ext4.h | 6 +
fs/ext4/file.c | 53 +++-
fs/ext4/indirect.c | 18 +-
fs/ext4/inode.c | 65 +++--
fs/ext4/namei.c | 10 +-
fs/ext4/super.c | 39 ++-
fs/open.c | 5 +-
include/linux/blkdev.h | 6 +-
include/linux/fs.h | 49 +++-
include/linux/mm.h | 1 +
include/linux/uio.h | 3 +
mm/Makefile | 1 -
mm/fadvise.c | 6 +-
mm/filemap.c | 6 +-
mm/filemap_xip.c | 483 -------------------------------------
mm/iov_iter.c | 237 ++++++++++++++++--
mm/madvise.c | 2 +-
mm/memory.c | 33 ++-
40 files changed, 1206 insertions(+), 881 deletions(-)
create mode 100644 Documentation/filesystems/dax.txt
delete mode 100644 Documentation/filesystems/xip.txt
create mode 100644 fs/dax.c
delete mode 100644 fs/ext2/xip.c
delete mode 100644 fs/ext2/xip.h
delete mode 100644 mm/filemap_xip.c

--
2.0.1

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