[RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

[Long Li]

From: Long Li <longli@xxxxxxxxxxxxx>

This patchset implements direct user I/O through RDMA.

In normal code path (even with cache=none), CIFS copies I/O data from
user-space to kernel-space for security reasons.

With this patchset, a new mounting option is introduced to have CIFS pin the 
user-space buffer into memory and performs I/O through RDMA. This avoids memory
copy, at the cost of added security risk.

This patchset is RFC. The work is in progress, do not merge.


Long Li (9):
  Introduce offset for the 1st page in data transfer structures
  Change wdata alloc to support direct pages
  Change rdata alloc to support direct pages
  Change function to support offset when reading pages
  Change RDMA send to regonize page offset in the 1st page
  Change RDMA recv to support offset in the 1st page
  Support page offset in memory regsitrations
  Implement no-copy file I/O interfaces
  Introduce cache=rdma moutning option
 

 fs/cifs/cifs_fs_sb.h      |   2 +
 fs/cifs/cifsfs.c          |  19 +++
 fs/cifs/cifsfs.h          |   3 +
 fs/cifs/cifsglob.h        |   6 +
 fs/cifs/cifsproto.h       |   4 +-
 fs/cifs/cifssmb.c         |  10 +-
 fs/cifs/connect.c         |  13 +-
 fs/cifs/dir.c             |   5 +
 fs/cifs/file.c            | 351 ++++++++++++++++++++++++++++++++++++++++++----
 fs/cifs/inode.c           |   4 +-
 fs/cifs/smb2ops.c         |   2 +-
 fs/cifs/smb2pdu.c         |  22 ++-
 fs/cifs/smbdirect.c       | 132 ++++++++++-------
 fs/cifs/smbdirect.h       |   2 +-
 fs/read_write.c           |   7 +
 include/linux/ratelimit.h |   2 +-
 16 files changed, 489 insertions(+), 95 deletions(-)

-- 
2.7.4