From d58f574bf39796ed2396dfd1e308352fbb03f944 Mon Sep 17 00:00:00 2001 From: "Michael R. Hines" Date: Mon, 22 Jul 2013 10:01:56 -0400 Subject: [PATCH] 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: Juan Quintela Tested-by: Michael R. Hines Signed-off-by: Michael R. Hines Signed-off-by: Juan Quintela --- migration.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/migration.c b/migration.c index 261975d0d1..fcdcf6196a 100644 --- a/migration.c +++ b/migration.c @@ -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);