diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 0554c48..d53e20f5 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -117,11 +117,33 @@
 		struct ext4_extent *ex;
 		depth = path->p_depth;
 
-		/* try to predict block placement */
+		/*
+		 * Try to predict block placement assuming that we are
+		 * filling in a file which will eventually be
+		 * non-sparse --- i.e., in the case of libbfd writing
+		 * an ELF object sections out-of-order but in a way
+		 * the eventually results in a contiguous object or
+		 * executable file, or some database extending a table
+		 * space file.  However, this is actually somewhat
+		 * non-ideal if we are writing a sparse file such as
+		 * qemu or KVM writing a raw image file that is going
+		 * to stay fairly sparse, since it will end up
+		 * fragmenting the file system's free space.  Maybe we
+		 * should have some hueristics or some way to allow
+		 * userspace to pass a hint to file system,
+		 * especiially if the latter case turns out to be
+		 * common.
+		 */
 		ex = path[depth].p_ext;
-		if (ex)
-			return (ext4_ext_pblock(ex) +
-				(block - le32_to_cpu(ex->ee_block)));
+		if (ex) {
+			ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
+			ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
+
+			if (block > ext_block)
+				return ext_pblk + (block - ext_block);
+			else
+				return ext_pblk - (ext_block - block);
+		}
 
 		/* it looks like index is empty;
 		 * try to find starting block from index itself */