[PATCH] loop allow highmem

[Hugh Dickins]

The loop driver forces the underlying inode's gfp_mask to GFP_NOIO.
But its own code seems fully kmapped, and if the underlying filesystem
says it can handle __GFP_HIGHMEM in its gfp_mask, why limit it?

--- 2.5.42-mm3/drivers/block/loop.c	Sat Oct 12 08:25:59 2002
+++ linux/drivers/block/loop.c	Tue Oct 15 13:14:34 2002
@@ -715,7 +715,7 @@
 		goto out_putf;
 	}
 	lo->old_gfp_mask = inode->i_mapping->gfp_mask;
-	inode->i_mapping->gfp_mask = GFP_NOIO;
+	inode->i_mapping->gfp_mask &= ~(__GFP_IO|__GFP_HIGHIO|__GFP_FS);
 
 	set_blocksize(bdev, block_size(lo_device));