Re: [PATCH 0/4] kernfs: remove kernfs_rwsem from dentry revalidation

[Christian Brauner]

On Thu, 20 Aug 2026 22:05:03 -0700, Shakeel Butt wrote:
> kernfs: remove kernfs_rwsem from dentry revalidation
> 
> At Meta, we are seeing important system daemons that poll cgroupfs and
> sysfs geth stuck in kernfs_dop_revalidate() for minutes. The two that
> hurt most are the ones we can least afford to lose: oomd, which decides
> what to kill when a machine runs out of memory, and below[1], which
> records the telemetry used to understand what happened afterwards.
> 
> [...]

Applied to the vfs-7.4.kernfs branch of the vfs/vfs.git tree.
Patches in the vfs-7.4.kernfs branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.4.kernfs

[1/4] kernfs: Use VFS lookup context in d_revalidate()
      https://git.kernel.org/vfs/vfs/c/b3c97f5cb084
[2/4] kernfs: Prepare directory revisions for lockless reads
      https://git.kernel.org/vfs/vfs/c/272e0997df44
[3/4] kernfs: Avoid namespace dereference in d_revalidate()
      https://git.kernel.org/vfs/vfs/c/e1c629a8dbc7
[4/4] kernfs: Remove kernfs_rwsem from dentry revalidation
      https://git.kernel.org/vfs/vfs/c/8c6ad578e2f0