Sorry for the delay in taking a look at things; this week has been horribly crazy busy for me. The conflict is with the folio changes in mm-stable and with Jan's "ext4: Cleanup data=journal writeback path" patch series. Both of these touch mpage_prepare_extent_to_map() in fs/ext4/inode.c quite extensively. [1] https://lore.kernel.org/r/20230111152736.9608-1-jack@xxxxxxx I've just tried taking Jan's patch series and applying it linux-next (which contains the mm-stable branch). Dealing with each chage one by one, there were conflits with patches #1, #4, #5, and #7. One at the time, the conflict resolutions weren't _that_ bad, but looking at the combined conflict after doing a "git merge" it was quite scary indeed. Maybe Linus's git merging-fu is much stronger than mine, but I certainly wouldn't wnat to try to resolve it just using "git merge"! So here's my proposed path forawrd. 1) So far the only testing Jan's patch series (modified so it sits on top of linux-next) is "it builds, ship it". So I'll kick off a full xfstests test on that series, and make sure I don't see any regressions. After that, I'll post it on linux-ext4 for Jan to examine. (Since it's well after work hours in Europe on a Friday, Jan probably won't get to it until Monday, which is fine.) 2) I'll drop Jan's patch set from the ext4 dev branch, and run the following full xfstests runs on this dev "lite" branch. (a) the dev "lite" branch by itself. (b) the dev "lite" branch merged with tip of Linux's tree. (c) the dev "lite" branch merged with linux-next. 99.9% of the time, when there are problems, they are detected by my full set of xfstests regression testing, since random users running linux-next tend not stress file system all that much, and the 0-day bot doesn't do nearly as much testing as I do. (I test a dozen different ext4 fs configs[2], while the 0-day tests only a single one.) [2] https://github.com/tytso/xfstests-bld/blob/master/test-appliance/files/root/fs/ext4/cfg/all.list 3) I'll then send the ext4 dev branch (minus the data=writepage cleanups) as a pull request to Linus. Next week, after Jan has a chance to review my patch conflict resolutions, I'll send a second pull request with the data=writepage cleanups. (As usual, I'll do my full set of test runs before sending the pull request.) Linus, are you OK with this plan? - Ted
