Re: [PATCH v2 3/9] migration: Change migrate_fd_ to migration_

[Peter Xu <peterx@redhat.com>]

On Tue, Feb 11, 2025 at 12:01:30PM -0300, Fabiano Rosas wrote:
> Remove all instances of _fd_ from the migration generic code. These
> functions have grown over time and the _fd_ part is now just
> confusing.
> 
> migration_fd_error() -> migration_error() makes it a little vague, so
> change it to migration_set_error_state().

I am ok on even renaming all of them if you prefer, but let me comment on
something, as not all of them apply to "fd is old concept"..

> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>  migration/channel.c    |  4 ++--
>  migration/migration.c  | 30 +++++++++++++++---------------
>  migration/migration.h  |  2 +-
>  migration/multifd.c    |  2 +-
>  migration/rdma.c       |  2 +-
>  migration/trace-events |  2 +-
>  6 files changed, 21 insertions(+), 21 deletions(-)
> 
> diff --git a/migration/channel.c b/migration/channel.c
> index f9de064f3b..24a91ef911 100644
> --- a/migration/channel.c
> +++ b/migration/channel.c
> @@ -74,7 +74,7 @@ void migration_channel_connect(MigrationState *s,
>              if (!error) {
>                  /* tls_channel_connect will call back to this
>                   * function after the TLS handshake,
> -                 * so we mustn't call migrate_fd_connect until then
> +                 * so we mustn't call migration_connect until then

migrate_fd_connect() makes some point only because of rdma, which can set
to_dst_file on its own.. which is indeed an fd (if we say fd~=qemufile)..

>                   */
>  
>                  return;
> @@ -89,7 +89,7 @@ void migration_channel_connect(MigrationState *s,
>              qemu_mutex_unlock(&s->qemu_file_lock);
>          }
>      }
> -    migrate_fd_connect(s, error);
> +    migration_connect(s, error);
>      error_free(error);
>  }
>  
> diff --git a/migration/migration.c b/migration/migration.c
> index e37842fdd2..db8d6e8ea7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1423,12 +1423,12 @@ static void migration_cleanup_json_writer(MigrationState *s)
>      g_clear_pointer(&s->vmdesc, json_writer_free);
>  }
>  
> -static void migrate_fd_cleanup(MigrationState *s)
> +static void migration_cleanup(MigrationState *s)
>  {
>      MigrationEventType type;
>      QEMUFile *tmp = NULL;
>  
> -    trace_migrate_fd_cleanup();
> +    trace_migration_cleanup();
>  
>      migration_cleanup_json_writer(s);
>  
> @@ -1485,9 +1485,9 @@ static void migrate_fd_cleanup(MigrationState *s)
>      yank_unregister_instance(MIGRATION_YANK_INSTANCE);
>  }
>  
> -static void migrate_fd_cleanup_bh(void *opaque)
> +static void migration_cleanup_bh(void *opaque)
>  {
> -    migrate_fd_cleanup(opaque);
> +    migration_cleanup(opaque);
>  }
>  
>  void migrate_set_error(MigrationState *s, const Error *error)
> @@ -1517,7 +1517,7 @@ static void migrate_error_free(MigrationState *s)
>      }
>  }
>  
> -static void migrate_fd_error(MigrationState *s, const Error *error)
> +static void migration_set_error_state(MigrationState *s, const Error *error)

This one also is slightly tricky, on that it is only used when fd connect
fails, so it has:

    assert(s->to_dst_file == NULL);

To avoid it being wrongly used during migration active, maybe rename it to
migration_connect_set_error()?

All look good otherwise.

>  {
>      MigrationStatus current = s->state;
>      MigrationStatus next;
> @@ -2198,7 +2198,7 @@ void qmp_migrate(const char *uri, bool has_channels,
>  
>  out:
>      if (local_err) {
> -        migrate_fd_error(s, local_err);
> +        migration_set_error_state(s, local_err);
>          error_propagate(errp, local_err);
>      }
>  }
> @@ -2243,7 +2243,7 @@ static void qmp_migrate_finish(MigrationAddress *addr, bool resume_requested,
>          if (!resume_requested) {
>              yank_unregister_instance(MIGRATION_YANK_INSTANCE);
>          }
> -        migrate_fd_error(s, local_err);
> +        migration_set_error_state(s, local_err);
>          error_propagate(errp, local_err);
>          return;
>      }
> @@ -3427,7 +3427,7 @@ static void migration_iteration_finish(MigrationState *s)
>          break;
>      }
>  
> -    migration_bh_schedule(migrate_fd_cleanup_bh, s);
> +    migration_bh_schedule(migration_cleanup_bh, s);
>      bql_unlock();
>  }
>  
> @@ -3455,7 +3455,7 @@ static void bg_migration_iteration_finish(MigrationState *s)
>          break;
>      }
>  
> -    migration_bh_schedule(migrate_fd_cleanup_bh, s);
> +    migration_bh_schedule(migration_cleanup_bh, s);
>      bql_unlock();
>  }
>  
> @@ -3837,7 +3837,7 @@ fail_setup:
>      return NULL;
>  }
>  
> -void migrate_fd_connect(MigrationState *s, Error *error_in)
> +void migration_connect(MigrationState *s, Error *error_in)
>  {
>      Error *local_err = NULL;
>      uint64_t rate_limit;
> @@ -3847,24 +3847,24 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
>      /*
>       * If there's a previous error, free it and prepare for another one.
>       * Meanwhile if migration completes successfully, there won't have an error
> -     * dumped when calling migrate_fd_cleanup().
> +     * dumped when calling migration_cleanup().
>       */
>      migrate_error_free(s);
>  
>      s->expected_downtime = migrate_downtime_limit();
>      if (error_in) {
> -        migrate_fd_error(s, error_in);
> +        migration_set_error_state(s, error_in);
>          if (resume) {
>              /*
>               * Don't do cleanup for resume if channel is invalid, but only dump
>               * the error.  We wait for another channel connect from the user.
>               * The error_report still gives HMP user a hint on what failed.
> -             * It's normally done in migrate_fd_cleanup(), but call it here
> +             * It's normally done in migration_cleanup(), but call it here
>               * explicitly.
>               */
>              error_report_err(error_copy(s->error));
>          } else {
> -            migrate_fd_cleanup(s);
> +            migration_cleanup(s);
>          }
>          return;
>      }
> @@ -3944,7 +3944,7 @@ fail:
>      migrate_set_error(s, local_err);
>      migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
>      error_report_err(local_err);
> -    migrate_fd_cleanup(s);
> +    migration_cleanup(s);
>  }
>  
>  static void migration_class_init(ObjectClass *klass, void *data)
> diff --git a/migration/migration.h b/migration/migration.h
> index 3547420c52..76afef34c4 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -484,7 +484,7 @@ bool  migration_has_all_channels(void);
>  void migrate_set_error(MigrationState *s, const Error *error);
>  bool migrate_has_error(MigrationState *s);
>  
> -void migrate_fd_connect(MigrationState *s, Error *error_in);
> +void migration_connect(MigrationState *s, Error *error_in);
>  
>  int migration_call_notifiers(MigrationState *s, MigrationEventType type,
>                               Error **errp);
> diff --git a/migration/multifd.c b/migration/multifd.c
> index ab73d6d984..d7ea8668ad 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -444,7 +444,7 @@ static bool multifd_send_cleanup_channel(MultiFDSendParams *p, Error **errp)
>           * channels have no I/O handler callback registered when reaching
>           * here, because migration thread will wait for all multifd channel
>           * establishments to complete during setup.  Since
> -         * migrate_fd_cleanup() will be scheduled in main thread too, all
> +         * migration_cleanup() will be scheduled in main thread too, all
>           * previous callbacks should guarantee to be completed when
>           * reaching here.  See multifd_send_state.channels_created and its
>           * usage.  In the future, we could replace this with an assert
> diff --git a/migration/rdma.c b/migration/rdma.c
> index 855753c671..76fb034923 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -4174,7 +4174,7 @@ void rdma_start_outgoing_migration(void *opaque,
>  
>      s->to_dst_file = rdma_new_output(rdma);
>      s->rdma_migration = true;
> -    migrate_fd_connect(s, NULL);
> +    migration_connect(s, NULL);
>      return;
>  return_path_err:
>      qemu_rdma_cleanup(rdma);
> diff --git a/migration/trace-events b/migration/trace-events
> index d22600abe6..58c0f07f5b 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -154,7 +154,7 @@ multifd_set_outgoing_channel(void *ioc, const char *ioctype, const char *hostnam
>  
>  # migration.c
>  migrate_set_state(const char *new_state) "new state %s"
> -migrate_fd_cleanup(void) ""
> +migration_cleanup(void) ""
>  migrate_error(const char *error_desc) "error=%s"
>  migration_cancel(void) ""
>  migrate_handle_rp_req_pages(const char *rbname, size_t start, size_t len) "in %s at 0x%zx len 0x%zx"
> -- 
> 2.35.3
> 

-- 
Peter Xu