blkdev: generalize flags for blkdev_issue_fn functions

The patch just convert all blkdev_issue_xxx function to common
set of flags. Wait/allocation semantics preserved.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c
index 8209f26..9492f60 100644
--- a/fs/ext3/fsync.c
+++ b/fs/ext3/fsync.c
@@ -91,7 +91,8 @@
 	 * storage
 	 */
 	if (test_opt(inode->i_sb, BARRIER))
-		blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
+		blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
+				BLKDEV_IFL_WAIT);
 out:
 	return ret;
 }