LU-13805 llite: add flag to disable unaligned DIO

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

diff --git a/lustre/llite/rw26.c b/lustre/llite/rw26.c
index 8f9511d..791feb0 100644 (file)
--- a/lustre/llite/rw26.c
+++ b/lustre/llite/rw26.c
@@ -498,10 +498,6 @@ ll_direct_IO_impl(struct kiocb *iocb, struct iov_iter *iter, int rw)
 
        ENTRY;
 
-       /* Check EOF by ourselves */
-       if (rw == READ && file_offset >= i_size_read(inode))
-               RETURN(0);
-
        if (file_offset & ~PAGE_MASK)
                unaligned = true;
 
@@ -519,6 +515,14 @@ ll_direct_IO_impl(struct kiocb *iocb, struct iov_iter *iter, int rw)
               (count >> PAGE_SHIFT) + !!(count & ~PAGE_MASK),
               MAX_DIO_SIZE >> PAGE_SHIFT, unaligned ? ", unaligned" : "");
 
+       /* Check EOF by ourselves */
+       if (rw == READ && file_offset >= i_size_read(inode))
+               RETURN(0);
+
+       /* unaligned DIO support can be turned off, so is it on? */
+       if (unaligned && !ll_sbi_has_unaligned_dio(ll_i2sbi(inode)))
+               RETURN(-EINVAL);
+
        /* the requirement to not return EIOCBQUEUED for pipes (see bottom of
         * this function) plays havoc with the unaligned I/O lifecycle, so
         * don't allow unaligned I/O on pipes