Commit d58f574b authored by Michael R. Hines's avatar Michael R. Hines Committed by Juan Quintela
Browse files

rdma: allow state transitions between other states besides ACTIVE 



This patch is in preparation for the next ones: Until now the MIG_STATE_SETUP
state was not really a 'formal' state. It has been used as a 'zero' state
and QEMU has been unconditionally transitioning into this state when
the QMP migrate command was called. In preparation for timing this state,
we have to make this state a a 'real' state which actually gets transitioned
from later in the migration_thread() from SETUP => ACTIVE, rather than just
automatically dropping into this state at the beginninig of the migration.

This means that the state transition function (migration_finish_set_state())
needs to be capable of transitioning from valid states _other_ than just
MIG_STATE_ACTIVE.

The function is in fact already capable of doing that, but was not allowing the
old state to be a parameter specified as an input.

This patch fixes that and only makes the transition if the current state
matches the old state that the caller intended to transition from.

Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Tested-by: default avatarMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: default avatarMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent 0033b8b4

migration.c

+6 −6
Original line number Diff line number Diff line
@@ -295,9 +295,9 @@ static void migrate_fd_cleanup(void *opaque) 
    notifier_list_notify(&migration_state_notifiers, s);

}



static void migrate_finish_set_state(MigrationState *s, int new_state)

static void migrate_set_state(MigrationState *s, int old_state, int new_state)

{

    if (atomic_cmpxchg(&s->state, MIG_STATE_ACTIVE, new_state) == new_state) {

    if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) {

        trace_migrate_set_state(new_state);

    }

}
@@ -315,7 +315,7 @@ static void migrate_fd_cancel(MigrationState *s) 
{

    DPRINTF("cancelling migration\n");



    migrate_finish_set_state(s, MIG_STATE_CANCELLED);

    migrate_set_state(s, s->state, MIG_STATE_CANCELLED);

}



void add_migration_state_change_notifier(Notifier *notify)
@@ -569,19 +569,19 @@ static void *migration_thread(void *opaque) 
                qemu_mutex_unlock_iothread();



                if (ret < 0) {

                    migrate_finish_set_state(s, MIG_STATE_ERROR);

                    migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);

                    break;

                }



                if (!qemu_file_get_error(s->file)) {

                    migrate_finish_set_state(s, MIG_STATE_COMPLETED);

                    migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);

                    break;

                }

            }

        }



        if (qemu_file_get_error(s->file)) {

            migrate_finish_set_state(s, MIG_STATE_ERROR);

            migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);

            break;

        }

        current_time = qemu_get_clock_ms(rt_clock);