Relevant merging during 2.4

zerocopy sendfile (2.4.4)
ext2 directories in pagecache (2.4.6)
VM rewrite (2.4.10)
blkdev-pagecache (2.4.10, part of it done better in 2.4.11 with the physical address space abstraction and removal of update_buffers not coherent hack)
O_DIRECT (2.4.10)
rbtree for vma (2.4.10)
ext3 (2.4.15)