[PATCH for-11.0 v2 0/7] migration: Error reporting cleanups

[Peter Xu <peterx@redhat.com>]

Based-on: <20251125070554.2256181-1-armbru@redhat.com>

This series is based on Markus's recent fix:

[PATCH] migration: Fix double-free on error path
https://lore.kernel.org/r/20251125070554.2256181-1-armbru@redhat.com

v2:
- Added R-bs
- Patch 1:
  - update commit message on s/accidentally merged/merged without proper
    review/ [Markus]
- Patch 2:
  - Added a new follow up patch here from Markus to poison Error's autoptr
- Patch 3:
  - Rename migration_connect_set_error to migration_connect_error_propagate
    [Markus]
  - Add comments in commit log for both migrate_connect() and the rename
    [Markus]
- Patch 4:
  - Rename multifd_send_set_error to multifd_send_error_propagate [Markus]
- Patch 6:
  - Make migrate_error_propagate() take MigrationState* as before [Markus]
  - Remove the one use case of g_clear_pointer() [Markus]
  - Touch up commit message for the change

This series should address the issues discussed in this thread here:

https://lore.kernel.org/r/871plmk1bc.fsf@pond.sub.org

The problem is Error is not a good candidate of g_autoptr, however the
cleanup function was merged without enough review.  Luckily, we only have
two users so far (after Markus's patch above lands).  This series removes
the last two in migration code and reverts the auto cleanup function for
Error.  Instead, poison the auto cleanup function.

When at it, it'll also change migrate_set_error() to start taking ownership
of errors, just like what most error APIs do.  When at it, it is renamed to
migrate_error_propagate() to imply migration version of error_propagate().

Comments welcomed, thanks.

Markus Armbruster (1):
  error: Poison g_autoptr(Error) to prevent its use

Peter Xu (6):
  migration: Use explicit error_free() instead of g_autoptr
  Revert "error: define g_autoptr() cleanup function for the Error type"
  migration: Make migration_connect_set_error() own the error
  migration: Make multifd_send_set_error() own the error
  migration: Make multifd_recv_terminate_threads() own the error
  migration: Replace migrate_set_error() with migrate_error_propagate()

 include/qapi/error.h             | 20 ++++++++++++-
 migration/migration.h            |  2 +-
 migration/channel.c              |  1 -
 migration/cpr-exec.c             |  5 ++--
 migration/migration.c            | 51 +++++++++++++++-----------------
 migration/multifd-device-state.c |  6 ++--
 migration/multifd.c              | 30 +++++++++----------
 migration/postcopy-ram.c         |  5 ++--
 migration/ram.c                  |  4 +--
 migration/savevm.c               | 17 +++++------
 10 files changed, 73 insertions(+), 68 deletions(-)

-- 
2.50.1