If users clearly know which file-backed pages to reclaim in system view, they
can use this ioctl() to register in advance and reclaim all at once later.

Change log from v2:
 - add more boundary checks
 - de-register the range, if len is zero

Jaegeuk Kim (2):
  f2fs: register inodes which is able to donate pages
  f2fs: add a sysfs entry to request donate file-backed pages

 Documentation/ABI/testing/sysfs-fs-f2fs |  7 +++
 fs/f2fs/debug.c                         |  3 ++
 fs/f2fs/f2fs.h                          | 14 +++++-
 fs/f2fs/file.c                          | 64 +++++++++++++++++++++++++
 fs/f2fs/inode.c                         | 14 ++++++
 fs/f2fs/shrinker.c                      | 27 +++++++++++
 fs/f2fs/super.c                         |  1 +
 fs/f2fs/sysfs.c                         |  8 ++++
 include/uapi/linux/f2fs.h               |  7 +++
 9 files changed, 144 insertions(+), 1 deletion(-)

-- 
2.48.0.rc2.279.g1de40edade-goog