From: Long Li <longli@microsoft.com>
Date: Wed, 31 Oct 2018 22:13:11 +0000
Subject: [PATCH] CIFS: Add direct I/O functions to file_operations
Git-commit: be4eb68846dc4450a9a4998d7c16d9f4955f9988
Patch-mainline: v4.20-rc1
References: bsc#1144333

With direct read/write functions implemented, add them to file_operations.

Dircet I/O is used under two conditions:
1. When mounting with "cache=none", CIFS uses direct I/O for all user file
data transfer.
2. When opening a file with O_DIRECT, CIFS uses direct I/O for all data
transfer on this file.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
 fs/cifs/cifsfs.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index b7ac09e38159..1b21262ec874 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1180,9 +1180,8 @@ const struct file_operations cifs_file_strict_ops = {
 };
 
 const struct file_operations cifs_file_direct_ops = {
-	/* BB reevaluate whether they can be done with directio, no cache */
-	.read_iter = cifs_user_readv,
-	.write_iter = cifs_user_writev,
+	.read_iter = cifs_direct_readv,
+	.write_iter = cifs_direct_writev,
 	.open = cifs_open,
 	.release = cifs_close,
 	.lock = cifs_lock,
@@ -1236,9 +1235,8 @@ const struct file_operations cifs_file_strict_nobrl_ops = {
 };
 
 const struct file_operations cifs_file_direct_nobrl_ops = {
-	/* BB reevaluate whether they can be done with directio, no cache */
-	.read_iter = cifs_user_readv,
-	.write_iter = cifs_user_writev,
+	.read_iter = cifs_direct_readv,
+	.write_iter = cifs_direct_writev,
 	.open = cifs_open,
 	.release = cifs_close,
 	.fsync = cifs_fsync,
-- 
2.16.4