On Thu, Oct 30, 2008 at 11:49:07AM -0700, Curt Wohlgemuth wrote: > > I'm working on a kernel tree based on 2.6.26, with patches from > > http://www2.kernel.org/pub/linux/kernel/people/tytso/ext4-patches/2.6.26-ext4-6/ > > applied as well. I'm trying to update our tree to a more recent set > of ext4 patches, and am having difficulty. > > Is there a simple recipe for this? Or am what I'm trying to do (use > latest patches with an older kernel) just asking for trouble? In general, the answer is "just asking for trouble", but git does have a way of making this easier. Effectively, what you'll need to do is forward-port fs/ext4 and fs/jbd2 so that you have the latest version into 2.6.26. As it turns out the latest ext4 patch queue (which has some bug fixes you'll want) is based on 2.6.28-rc2, so you'll want to extract out all patches that touch the fs/ext4 directory between 2.6.26 and 2.6.28-rc2. I happen to know that since 2.6.26 some of the changes in fs/ext4 depend on two changes that we made to include/linux/percpu_counter.h (and I've checked to make sure those were the only two changes we cared about between 2.6.26 and 2.6.28-rc2). So to generate the list of SHA1 hashes, we use git in a Linux 2.6 repository: git rev-list --reverse v2.6.26..v2.6.28-rc2 -- fs/ext4 fs/jbd2 include/linux/percpu_counter.h Documentation/filesystems/ext4.txt > /tmp/revs We can then create a Unix mbox of all of these patches: git show --pretty=email `cat /tmp/revs` > /tmp/ext4-patches I then reviewed this list using my favoriate mailreader (which happens to be mutt, but you can use any mail reader that understands Unix mbox), and found a few patches that will probably depend on other changes that were made since 2.6.26: 51cc50685a4275c6a02653670af9f108a64e01cf e6305c43eda10ebfd2ad9e35d6e172ccc7bb3695 77e69dac3cefacee939cb107ae9cd520a62338e0 8f616cd5249e03c9e1b371623d85e76d4b86bbc1 529ae9aaa08378cfe2a4350bded76f32cc8ff0ce 4f3e7524b2e703d9f8b02ac338153a53dd7ede66 3295f0ef9ff048a4619ede597ad9ec9cab725654 23a0ee908cbfba3264d19729c67c22b20fa73886 6da0b38f4433fb0f24615449d7966471b6e5eae0 9a1c3542768b5a58e45a9216921cd10a3bae1205 8264613def2e5c4f12bc3167713090fd172e6055 440037287c5ebb07033ab927ca16bb68c291d309 22484856402bfa1ff3defe47f6029ab0418240d9 If you were to then remove these SHA1 hashes from the /tmp/revs list, and then re-run the "git show --pretty=email..." command, I *think* that if you take that resulting set of patches, it *should* apply to 2.6.26, and that it *should* compile and result in a valid kernel. I haven't tried it myself, though. I would then take the patches from the ext4 patch queue to get some latest patches that you'll probably need. Hope this helps, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
