On Tue, Jun 17, 2025 at 10:55:33PM +0200, Amir Goldstein wrote:
Sasha,
This 5.15 backport is needed to fix a regression introduced to test generic/417 in kernel v5.15.176. With this backport, kernel v5.15.185 passed the fstests quick run.
As you may have noticed, 5.15.y (and 5.10.y) are not being actively maintained by xfs stable maintainer who moved their focus to 6.*.y LTS kernels.
The $SUBJECT commit is a dependency of commit 74ad4693b647, as hinted by the wording: "In the next patch, we're going to... This requires...".
Indeed, Leah has backported commit 74ad4693b647 to 6.1.y along with its dependency, yet somehow, commit 74ad4693b647 found its way to v5.15.176, without the dependency and without the xfs stable review process.
Judging by the line: Stable-dep-of: 652f03db897b ("xfs: remove unknown compat feature check in superblock write validation") that exists only in the 5.15.y tree, I deduce that your bot has auto selected this patch in the process of backporting the commit 652f03db897b, which was explicitly marked for stable v4.19+ [1].
I don't know if there is a lesson to be learned from this incident. Applying xfs backports without running fstests regression is always going to be a gamble. I will leave it up to you to decide if anything in the process of applying xfs patches to <= v5.15.y needs to change.
My scripts don't filter out commits with a stable tag like they do for commits without. This was safe until they also started pulling in more commits as dependencies to resolve conflicts.
I'll fix it on my end by adding the same filter for stable tagged commits as well.
Thanks for the fix! I'll queue it up for this upcoming release.