LU-13805 llite: Implement unaligned DIO connect flag

[fs/lustre-release.git] / lustre / llite / rw26.c

diff --git a/lustre/llite/rw26.c b/lustre/llite/rw26.c
index 142a693..4b45abc 100644 (file)
--- a/lustre/llite/rw26.c
+++ b/lustre/llite/rw26.c
@@ -540,6 +540,12 @@ ll_direct_IO_impl(struct kiocb *iocb, struct iov_iter *iter, int rw)
        io = lcc->lcc_io;
        LASSERT(io != NULL);
 
+       /* this means we encountered an old server which can't safely support
+        * unaligned DIO, so we have to disable it
+        */
+       if (unaligned && !cl_io_top(io)->ci_allow_unaligned_dio)
+               RETURN(-EINVAL);
+
        /* if one part of an I/O is unaligned, just handle all of it that way -
         * otherwise we create significant complexities with managing the iovec
         * in different ways, etc, all for very marginal benefits