[Virtio-fs] [PATCH 0/3][V2] virtio-fs: Create a read-write mapping only if needed

[Vivek Goyal]

This is V2 of patches.

Changes since V1:

- Fixed the issue of dropping lock (liu bo)
- Mapping could already be made writable by another thread after
  dropping read lock and acquiring write-lock. So check for that. 

Do not always create a read-write mapping. Create it read-write only if
caller asked for it. Otherwise create a read-only mapping and upgrade
it to read-write later when needed.

Vivek Goyal (3):
  fuse: Get rid of file parameter from setup mapping
  fuse: Move new mapping setup code in a function
  fuse: Add logic to upgrade a read-only mapping to read-write

 fs/fuse/file.c   | 253 +++++++++++++++++++++++++++++------------------
 fs/fuse/fuse_i.h |   3 +
 2 files changed, 162 insertions(+), 94 deletions(-)

-- 
2.17.2