[PATCH 4.9 33/64] SMB3: Dont ignore O_SYNC/O_DSYNC and O_DIRECT flags

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Steve French <smfrench@xxxxxxxxx>

commit 1013e760d10e614dc10b5624ce9fc41563ba2e65 upstream.

Signed-off-by: Steve French <smfrench@xxxxxxxxx>
Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Reviewed-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/cifs/file.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -224,6 +224,13 @@ cifs_nt_open(char *full_path, struct ino
 	if (backup_cred(cifs_sb))
 		create_options |= CREATE_OPEN_BACKUP_INTENT;
 
+	/* O_SYNC also has bit for O_DSYNC so following check picks up either */
+	if (f_flags & O_SYNC)
+		create_options |= CREATE_WRITE_THROUGH;
+
+	if (f_flags & O_DIRECT)
+		create_options |= CREATE_NO_BUFFER;
+
 	oparms.tcon = tcon;
 	oparms.cifs_sb = cifs_sb;
 	oparms.desired_access = desired_access;