cifs: Allow directIO read/write during cache=strict

Currently cifs have all or nothing approach for directIO operations.
cache=strict mode does not allow directIO while cache=none mode performs
all the operations as directIO even when user does not specify O_DIRECT
flag. This patch enables strict cache mode to honour directIO semantics.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 3db0c5fd9a11..6cbd9c688cfe 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -497,6 +497,14 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
                 goto out;
         }
 
+        if (file->f_flags & O_DIRECT &&
+            CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
+                if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
+                        file->f_op = &cifs_file_direct_nobrl_ops;
+                else
+                        file->f_op = &cifs_file_direct_ops;
+                }
+
         file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
         if (file_info == NULL) {
                 if (server->ops->close)