[Patch v3 00/16] CIFS: add support for direct I/O

From: Long Li
Date: Fri Sep 07 2018 - 22:15:27 EST


From: Long Li <longli@xxxxxxxxxxxxx>

This patch set implements direct I/O.

In normal code path (even with cache=none), CIFS copies I/O data from
user-space to kernel-space for security reasons of possible protocol
required signing and encryption on user data.

With this patch set, CIFS passes the I/O data directly from user-space
buffer to the transport layer, when file system is mounted with
"cache-none".

Patch v2 addressed comments from Christoph Hellwig <hch@xxxxxx> and
Tom Talpey <ttalpey@xxxxxxxxxxxxx> to implement direct I/O for both
socket and RDMA.

Patch v3 added support for kernel AIO.


Long Li (16):
CIFS: Add support for direct pages in rdata
CIFS: Use offset when reading pages
CIFS: Add support for direct pages in wdata
CIFS: pass page offset when issuing SMB write
CIFS: Calculate the correct request length based on page offset and
tail size
CIFS: Introduce helper function to get page offset and length in
smb_rqst
CIFS: When sending data on socket, pass the correct page offset
CIFS: SMBD: Support page offset in RDMA send
CIFS: SMBD: Support page offset in RDMA recv
CIFS: SMBD: Do not call ib_dereg_mr on invalidated memory registration
CIFS: SMBD: Support page offset in memory registration
CIFS: Pass page offset for calculating signature
CIFS: Pass page offset for encrypting
CIFS: Add support for direct I/O read
CIFS: Add support for direct I/O write
CIFS: Add direct I/O functions to file_operations

fs/cifs/cifsencrypt.c | 9 +-
fs/cifs/cifsfs.c | 10 +-
fs/cifs/cifsfs.h | 2 +
fs/cifs/cifsglob.h | 11 +-
fs/cifs/cifsproto.h | 9 +-
fs/cifs/cifssmb.c | 19 +-
fs/cifs/connect.c | 5 +-
fs/cifs/file.c | 477 ++++++++++++++++++++++++++++++++++++++++++--------
fs/cifs/misc.c | 17 ++
fs/cifs/smb2ops.c | 22 ++-
fs/cifs/smb2pdu.c | 20 ++-
fs/cifs/smbdirect.c | 156 ++++++++++-------
fs/cifs/smbdirect.h | 2 +-
fs/cifs/transport.c | 34 ++--
14 files changed, 606 insertions(+), 187 deletions(-)

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2.7.4