[v3,0/3] ovl: metacopy/verity fixes and improvements

Message

Miklos Szeredi April 8, 2025, 3:40 p.m. UTC

The main purpose of this patchset is allowing metadata/data-only layers to
be usable in user namespaces (without super user privs).  The main use case
is composefs in unprivileged containers.

Will post xfstests testcases shortly.

v3:
 - consistently refuse following redirect/metacopy for upper found through
   index (dropped RVB's due to this change)
 - move redirect/metacopy check into helper
 - remove verity -> metacopy dependency (Amir)
 - stable fixes moved to git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs.git#ovl-fixes

v2:
 - drop broken hunk in param.c (Amir)
 - patch header improvements (Amir)


---
Miklos Szeredi (3):
  ovl: make redirect/metacopy rejection consistent
  ovl: relax redirect/metacopy requirements for lower -> data redirect
  ovl: don't require "metacopy=on" for "verity"

 Documentation/filesystems/overlayfs.rst |  7 ++
 fs/overlayfs/namei.c                    | 89 +++++++++++++++++--------
 fs/overlayfs/params.c                   | 31 +--------
 3 files changed, 71 insertions(+), 56 deletions(-)