Hi all,

This series removes the fixed limits on the number of files that can
be preserved within a single session, and the total number of sessions
managed by the Live Update Orchestrator (LUO).

The core of the change is a transition from single contiguous memory
blocks for metadata serialization to a chain of linked blocks. This
allows LUO to scale dynamically.

1.  ABI Evolution:
    - Introduced linked-block headers for both file and session
      serialization.
    - Bumped session ABI version to v4.

2.  Memory Management & Security:
    - Implemented a dynamic block allocation and reuse strategy. Blocks
      are allocated only when existing ones are exhausted and are reused
      during session/file removal cycles.
    - Introduced KHO_MAX_BLOCKS (10000) as a safeguard against stupid
      excessive allocations or corrupted cyclic lists during restore.

3.  Expanded Selftests:
    - Added new kexec-based tests verifying preservation of
      2000 sessions and 500 files per session.
    - Added self-tests for many sessions and many files management.

Tree: git.kernel.org/pub/scm/linux/kernel/git/tatashin/linux.git
Branch: luo-remove-max-files-sessions-limits/v6

Changes v7:
- Addressed comments from Mike.
- For changes in kho_block.c, and updated to use gloval KHO compatability.
- Collected review-by's and acks.

Please review.

Thanks,
Pasha

Pasha Tatashin (13):
  liveupdate: change file_set->count type to u64 for type safety
  liveupdate: avoid mixing cleanup guards with goto in
    luo_session_retrieve_fd
  liveupdate: centralize state management into struct luo_ser
  liveupdate: register luo_ser as KHO subtree
  liveupdate: Extract luo_file_deserialize_one helper
  liveupdate: Extract luo_session_deserialize_one helper
  kho: add support for linked-block serialization
  liveupdate: defer session block allocation and physical address
    setting
  liveupdate: Remove limit on the number of sessions
  liveupdate: Remove limit on the number of files per session
  selftests/liveupdate: Test session and file limit removal
  selftests/liveupdate: Add stress-sessions kexec test
  selftests/liveupdate: Add stress-files kexec test

 Documentation/core-api/kho/abi.rst            |   5 +
 Documentation/core-api/kho/index.rst          |  11 +
 MAINTAINERS                                   |   1 +
 include/linux/kho/abi/block.h                 |  54 +++
 include/linux/kho/abi/kexec_handover.h        |   2 +-
 include/linux/kho/abi/luo.h                   | 148 ++-----
 include/linux/kho_block.h                     | 106 +++++
 kernel/liveupdate/Makefile                    |   1 +
 kernel/liveupdate/kho_block.c                 | 416 ++++++++++++++++++
 kernel/liveupdate/luo_core.c                  |  99 ++---
 kernel/liveupdate/luo_file.c                  | 205 ++++-----
 kernel/liveupdate/luo_flb.c                   |  60 +--
 kernel/liveupdate/luo_internal.h              |  16 +-
 kernel/liveupdate/luo_session.c               | 219 +++++----
 tools/testing/selftests/liveupdate/Makefile   |   2 +
 .../testing/selftests/liveupdate/liveupdate.c |  75 ++++
 .../selftests/liveupdate/luo_stress_files.c   |  97 ++++
 .../liveupdate/luo_stress_sessions.c          | 102 +++++
 .../selftests/liveupdate/luo_test_utils.c     |  24 +
 .../selftests/liveupdate/luo_test_utils.h     |   2 +
 20 files changed, 1199 insertions(+), 446 deletions(-)
 create mode 100644 include/linux/kho/abi/block.h
 create mode 100644 include/linux/kho_block.h
 create mode 100644 kernel/liveupdate/kho_block.c
 create mode 100644 tools/testing/selftests/liveupdate/luo_stress_files.c
 create mode 100644 tools/testing/selftests/liveupdate/luo_stress_sessions.c


base-commit: 2935777b418d2bfcbfe96705bb2c0fa6c0d94e18
-- 
2.53.0

On Wed, 03 Jun 2026 15:43:49 +0000, Pasha Tatashin wrote:
> liveupdate: Remove limits on sessions and files
> 
> Hi all,
> 
> This series removes the fixed limits on the number of files that can
> be preserved within a single session, and the total number of sessions
> managed by the Live Update Orchestrator (LUO).
> 
> [...]

Applied to next branch of liveupdate/linux.git tree, thanks!

[01/13] liveupdate: change file_set->count type to u64 for type safety
        commit: 81fbb909ec07868415f6b2269922c8d1cc6a215a
[02/13] liveupdate: avoid mixing cleanup guards with goto in luo_session_retrieve_fd
        commit: 6af06e11bd48bdefaf9381f6ff0bd65b1e5d98ab
[03/13] liveupdate: centralize state management into struct luo_ser
        commit: d376e4b55c9a0adb3e701c7eaff21d9ba655a1c6
[04/13] liveupdate: register luo_ser as KHO subtree
        commit: cf071b3536df76a2a75b83ca1fe8c043824352c3
[05/13] liveupdate: Extract luo_file_deserialize_one helper
        commit: 51b71af922a7145e63fdc0cab075d681ecd89e4a
[06/13] liveupdate: Extract luo_session_deserialize_one helper
        commit: be9d10d167652e11283cd07c7daf187222808db1
[07/13] kho: add support for linked-block serialization
        commit: 0349ff2887059112ce06831ab29aec47a2a7285a
[08/13] liveupdate: defer session block allocation and physical address setting
        commit: b5a58a922e6f2f9f40faddd8e0e1fe3ce0ea9c56
[09/13] liveupdate: Remove limit on the number of sessions
        commit: 2a441a14c2c03b39d1c89438dd28cef9d8fa57d5
[10/13] liveupdate: Remove limit on the number of files per session
        commit: 1d1153097f4dd417e2ea00404edec9fbd1d88f28
[11/13] selftests/liveupdate: Test session and file limit removal
        commit: 5ba3f30643cbdd79fb82e525aa1ca55b62fcc7ac
[12/13] selftests/liveupdate: Add stress-sessions kexec test
        commit: 3432292fb9130191dca57953941f7ae3888d52d8
[13/13] selftests/liveupdate: Add stress-files kexec test
        commit: 46429a15a6dfe522880d5085f1f6999357758872

tree: https://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux
branch: next

--
Sincerely yours,
Mike.