[PATCH v4 0/3] fuse: add a new fuse init flag to relax restrictions in no cache mode

[Hao Xu <hao.xu@linux.dev>]

From: Hao Xu <howeyxu@tencent.com>

Patch 1 is a fix for private mmap in FOPEN_DIRECT_IO mode
  This is added here together since the later two depends on it.
Patch 2 is the main dish
Patch 3 is to maintain direct io logic for shared mmap in FOPEN_DIRECT_IO mode

v3 -> v4
    fix race condition for buffered write and direct read by flushing
    pages before direct read to avoid to get stale data

v2 -> v3
    add patch 1 fix here, and adjust it follow Bernd's comment
    add patch 3 which does right thing for shared mmap in FOPEN_DIRECT_IO mode

v1 -> v2:
     make the new flag a fuse init one rather than a open flag since it's
     not common that different files in a filesystem has different
     strategy of shared mmap.


Hao Xu (3):
  fuse: invalidate page cache pages before direct write
  fuse: add a new fuse init flag to relax restrictions in no cache mode
  fuse: write back dirty pages before direct write in direct_io_relax
    mode

 fs/fuse/file.c            | 26 +++++++++++++++++++++++---
 fs/fuse/fuse_i.h          |  3 +++
 fs/fuse/inode.c           |  5 ++++-
 include/uapi/linux/fuse.h |  4 ++++
 4 files changed, 34 insertions(+), 4 deletions(-)


base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
-- 
2.25.1