Merge patch series "Rework simple xattrs"

Christian Brauner (Amutable) <brauner@kernel.org> says:

Rework the simple xattrs api to make it more efficient and easier to
use for all consumers.

* patches from https://patch.msgid.link/20260605135322.2632068-1-mszeredi@redhat.com:
  simpe_xattr: use per-sb cache
  simple_xattr: change interface to pass struct simple_xattrs **
  tmpfs: simplify constructing "security.foo" xattr names
  kernfs: fix xattr race condition with multiple superblocks

Link: https://patch.msgid.link/20260605135322.2632068-1-mszeredi@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>