[PATCH v2 0/2] memfd_luo: keep memfd frozen until finish

[Pratyush Yadav <pratyush@kernel.org>]

From: "Pratyush Yadav (Google)" <pratyush@kernel.org>

Hi,

This series keeps a retrieved memfd frozen until finish. The main
motivation is to let dependents like iommufd have a chance to acquire a
reference. It also fits conceptually: finish is the point when the file
should be back to "normal".

Patch 1 allows keeping private_data from retrieve to finish. This is
needed by memfd to keep hold of folios_ser, which it uses to give up its
pins.

Patch 2 does the main change.

The series is based on
https://lore.kernel.org/kexec/20261103172251.2348370-1-pratyush@kernel.org/T/#u.

Changes in v2:
- Replace the stale reference to the 'data' field in the struct
liveupdate_file_op_args kerneldoc with 'file', 'serialized_data' and
'private_data'. (Pasha)
- Collect Reviewed-by tags from Pasha.
- Rebase on the latest liveupdate/next.

v1: https://lore.kernel.org/all/20261103181916.2462825-1-pratyush@kernel.org/

Regards,
Pratyush Yadav

Pratyush Yadav (Google) (2):
  liveupdate: luo_file: allow keeping private_data from retrieve until
    finish
  mm/memfd_luo: keep memfd frozen until finish

 include/linux/liveupdate.h   | 11 +++--
 kernel/liveupdate/luo_file.c | 11 +++--
 mm/memfd_luo.c               | 87 ++++++++++++++++++++++++++++--------
 3 files changed, 83 insertions(+), 26 deletions(-)

-- 
2.56.0.542.g3ef89b7020-goog