* Peter Xu (pet...@redhat.com) wrote:
> It's efficient, but hackish to call yank unregister calls in channel_close(),
> especially it'll be hard to debug when qemu crashed with some yank function
> leaked.
>
> Remove that hack, but instead explicitly unregister yank functions at the
> places where needed, they are:
>
> (on src)
> - migrate_fd_cleanup
> - postcopy_pause
>
> (on dst)
> - migration_incoming_state_destroy
> - postcopy_pause_incoming
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
> ---
> migration/migration.c | 5 +++++
> migration/qemu-file-channel.c | 3 ---
> migration/savevm.c | 7 +++++++
> migration/yank_functions.c | 14 ++++++++++++++
> migration/yank_functions.h | 1 +
> 5 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index fa70400f98..bfeb65b8f7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -59,6 +59,7 @@
> #include "multifd.h"
> #include "qemu/yank.h"
> #include "sysemu/cpus.h"
> +#include "yank_functions.h"
>
> #define MAX_THROTTLE (128 << 20) /* Migration transfer speed
> throttling */
>
> @@ -273,6 +274,7 @@ void migration_incoming_state_destroy(void)
> }
>
> if (mis->from_src_file) {
> + migration_ioc_unregister_yank_from_file(mis->from_src_file);
> qemu_fclose(mis->from_src_file);
> mis->from_src_file = NULL;
> }
> @@ -1811,6 +1813,7 @@ static void migrate_fd_cleanup(MigrationState *s)
> * Close the file handle without the lock to make sure the
> * critical section won't block for long.
> */
> + migration_ioc_unregister_yank_from_file(tmp);
> qemu_fclose(tmp);
> }
>
> @@ -3352,6 +3355,8 @@ static MigThrError postcopy_pause(MigrationState *s)
>
> /* Current channel is possibly broken. Release it. */
> assert(s->to_dst_file);
> + /* Unregister yank for current channel */
> + migration_ioc_unregister_yank_from_file(s->to_dst_file);
Should this go inside the lock?
Dave
> qemu_mutex_lock(&s->qemu_file_lock);
> file = s->to_dst_file;
> s->to_dst_file = NULL;
> diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
> index 2f8b1fcd46..bb5a5752df 100644
> --- a/migration/qemu-file-channel.c
> +++ b/migration/qemu-file-channel.c
> @@ -107,9 +107,6 @@ static int channel_close(void *opaque, Error **errp)
> int ret;
> QIOChannel *ioc = QIO_CHANNEL(opaque);
> ret = qio_channel_close(ioc, errp);
> - if (OBJECT(ioc)->ref == 1) {
> - migration_ioc_unregister_yank(ioc);
> - }
> object_unref(OBJECT(ioc));
> return ret;
> }
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 96b5e5d639..7b7b64bd13 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -65,6 +65,7 @@
> #include "qemu/bitmap.h"
> #include "net/announce.h"
> #include "qemu/yank.h"
> +#include "yank_functions.h"
>
> const unsigned int postcopy_ram_discard_version;
>
> @@ -2568,6 +2569,12 @@ static bool
> postcopy_pause_incoming(MigrationIncomingState *mis)
> /* Clear the triggered bit to allow one recovery */
> mis->postcopy_recover_triggered = false;
>
> + /*
> + * Unregister yank with either from/to src would work, since ioc behind
> it
> + * is the same
> + */
> + migration_ioc_unregister_yank_from_file(mis->from_src_file);
> +
> assert(mis->from_src_file);
> qemu_file_shutdown(mis->from_src_file);
> qemu_fclose(mis->from_src_file);
> diff --git a/migration/yank_functions.c b/migration/yank_functions.c
> index 23697173ae..8c08aef14a 100644
> --- a/migration/yank_functions.c
> +++ b/migration/yank_functions.c
> @@ -14,6 +14,7 @@
> #include "qemu/yank.h"
> #include "io/channel-socket.h"
> #include "io/channel-tls.h"
> +#include "qemu-file.h"
>
> void migration_yank_iochannel(void *opaque)
> {
> @@ -46,3 +47,16 @@ void migration_ioc_unregister_yank(QIOChannel *ioc)
> QIO_CHANNEL(ioc));
> }
> }
> +
> +void migration_ioc_unregister_yank_from_file(QEMUFile *file)
> +{
> + QIOChannel *ioc = qemu_file_get_ioc(file);
> +
> + if (ioc) {
> + /*
> + * For migration qemufiles, we'll always reach here. Though we'll
> skip
> + * calls from e.g. savevm/loadvm as they don't use yank.
> + */
> + migration_ioc_unregister_yank(ioc);
> + }
> +}
> diff --git a/migration/yank_functions.h b/migration/yank_functions.h
> index 74c7f18c91..a7577955ed 100644
> --- a/migration/yank_functions.h
> +++ b/migration/yank_functions.h
> @@ -17,3 +17,4 @@
> void migration_yank_iochannel(void *opaque);
> void migration_ioc_register_yank(QIOChannel *ioc);
> void migration_ioc_unregister_yank(QIOChannel *ioc);
> +void migration_ioc_unregister_yank_from_file(QEMUFile *file);
> --
> 2.31.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
