cifs: Allow using O_DIRECT with cache=loose

Currently O_DIRECT is supported with cache=none and cache=strict, but
not cache=loose. Add support for using O_DIRECT when mounted with
cache=loose.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 53e343d073bb..565a4c0d2ee9 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -754,6 +754,9 @@ cifs_loose_read_iter(struct kiocb *iocb, struct iov_iter *iter)
         ssize_t rc;
         struct inode *inode = file_inode(iocb->ki_filp);
 
+        if (iocb->ki_filp->f_flags & O_DIRECT)
+                return cifs_user_readv(iocb, iter);
+
         rc = cifs_revalidate_mapping(inode);
         if (rc)
                 return rc;
@@ -768,6 +771,18 @@ static ssize_t cifs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
         ssize_t written;
         int rc;
 
+        if (iocb->ki_filp->f_flags & O_DIRECT) {
+                written = cifs_user_writev(iocb, from);
+                if (written > 0 && CIFS_CACHE_READ(cinode)) {
+                        cifs_zap_mapping(inode);
+                        cifs_dbg(FYI,
+                                 "Set no oplock for inode=%p after a write operation\n",
+                                 inode);
+                        cinode->oplock = 0;
+                }
+                return written;
+        }
+
         written = cifs_get_writer(cinode);
         if (written)
                 return written;