fix: check for O_DIRECT support for reads and writes (#11331)

In-case user enables O_DIRECT for reads and backend does
not support it we shall proceed to turn it off instead
and print a warning. This validation avoids any unexpected
downtimes that users may incur.

cmd/fs-v1.go

@@ -123,7 +123,7 @@ func NewFSObjectLayer(fsPath string) (ObjectLayer, error) {
 	}
 
 	var err error
-	if fsPath, err = getValidPath(fsPath, false); err != nil {
+	if fsPath, err = getValidPath(fsPath); err != nil {
 		if err == errMinDiskSize {
 			return nil, config.ErrUnableToWriteInBackend(err).Hint(err.Error())
 		}