On Tue, Jul 19, 2022 at 02:25:18PM +0200, Greg KH wrote:
95% of the time we take a patch that is not in Linus's tree, it is buggy and causes problems in the long run.
So if we really want a 4.19 LTS specific patch, I'd be OK with signing off on it from an ext4 perspective.... IF AND ONLY IF someone is willing to tell me that they ran "kvm-xfstests -c ext4/all -g auto" or the equivalent before and after applying the patch, and is willing to certify that there are no test regressions.
Helpful links:
* https://thunk.org/gce-xfstests * https://thunk.org/android-xfstests * Documentation links from https://github.com/tytso/xfstests-bld * https://github.com/tytso/xfstests-bld/blob/master/Documentation/kvm-quicksta... * https://github.com/tytso/xfstests-bld/blob/master/Documentation/gce-xfstests...
(Note that running "-c ext4/all -g auto" will take some 12+ hours if the tests are run serially, which is why using gce-xfstests's lightweight test manager to run the file system test configurations in parallel is a big win.)
Or better yet, take the effort here and move off of 4.19 to a newer kernel without this problem in it. What is preventing you from doing that today? 4.19 is not going to be around for forever, and will probably not even be getting fixes for stuff like RETBLEED, so are you _SURE_ you want to keep using it?
Or yeah, maybe it's better/cheaper/time for you to move off of 4.19. :-)
- Ted
P.S. If we go down this path, Greg K-H may also insist on getting the bug fix to the 5.4 LTS kernel, so that a bug isn't just fixed in 4.19 LTS but not 5.4 LTS. In which case, the same requirement of running "-c ext4/all -g auto" and showing that there are no test regressions is going to be a requirement for 5.4 LTS as well.