* Leonardo Bras (leob...@redhat.com) wrote:
> Currently, if a qemu instance is started with "-incoming defer" and
> an incorect parameter is passed to "migrate_incoming", it will print the
> expected error and reply with "duplicate yank instance" for any upcoming
> "migrate_incoming" command.
>
> This renders current qemu process unusable, and requires a new qemu
> process to be started before accepting a migration.
>
> This is caused by a yank_register_instance() that happens in
> qemu_start_incoming_migration() but is never reverted if any error
> happens.
>
> Solves this by unregistering the instance if anything goes wrong
> in the function, allowing a new "migrate_incoming" command to be
> accepted.
>
> Fixes: b5eea99ec2f ("migration: Add yank feature", 2021-01-13)
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1974366
> Signed-off-by: Leonardo Bras <leob...@redhat.com>
> Reviewed-by: Peter Xu <pet...@redhat.com>
>
> ---
> Changes since v1:
> - Add ERRP_GUARD() at the beginning of the function, so it deals with
> errp passed as NULL, and does correct error propagation.
Thanks;
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> migration/migration.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 4228635d18..af0c72609f 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -454,6 +454,7 @@ void migrate_add_address(SocketAddress *address)
>
> static void qemu_start_incoming_migration(const char *uri, Error **errp)
> {
> + ERRP_GUARD();
> const char *p = NULL;
>
> if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
> @@ -474,9 +475,13 @@ static void qemu_start_incoming_migration(const char
> *uri, Error **errp)
> } else if (strstart(uri, "fd:", &p)) {
> fd_start_incoming_migration(p, errp);
> } else {
> - yank_unregister_instance(MIGRATION_YANK_INSTANCE);
> error_setg(errp, "unknown migration protocol: %s", uri);
> }
> +
> + if (*errp) {
> + yank_unregister_instance(MIGRATION_YANK_INSTANCE);
> + }
> +
> }
>
> static void process_incoming_migration_bh(void *opaque)
> --
> 2.32.0
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
