Re: [Qemu-devel] [PATCH] block: Cleanup BMDS in bdrv_close_all

[Juan Quintela <quintela@redhat.com>]

Fam Zheng <famz@redhat.com> wrote:
> This fixes the assertion due to op blockers added by BMDS:
>
> block.c:3248: bdrv_delete: Assertion `bdrv_op_blocker_is_empty(bs)' failed.
>
> Reproducer: simply start block migration and quit QEMU before it ends.
>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Fam Zheng <famz@redhat.com>

No need for one stub, see later.


> ---
>  block.c                 | 2 ++
>  migration/block.c       | 2 +-
>  migration/block.h       | 1 +
>  stubs/Makefile.objs     | 1 +
>  stubs/block-migration.c | 6 ++++++
>  5 files changed, 11 insertions(+), 1 deletion(-)
>  create mode 100644 stubs/block-migration.c
>
> diff --git a/block.c b/block.c
> index 3308814bba..508a57274d 100644
> --- a/block.c
> +++ b/block.c
> @@ -43,6 +43,7 @@
>  #include "qemu/cutils.h"
>  #include "qemu/id.h"
>  #include "qapi/util.h"
> +#include "migration/block.h"

this should be misc.h

>  
>  #ifdef CONFIG_BSD
>  #include <sys/ioctl.h>
> @@ -3111,6 +3112,7 @@ static void bdrv_close(BlockDriverState *bs)
>  
>  void bdrv_close_all(void)
>  {
> +    block_migration_cleanup_bmds();
>      block_job_cancel_sync_all();
>      nbd_export_close_all();
>  

> diff --git a/migration/block.h b/migration/block.h
> index 22ebe94259..8bae1cf55a 100644
> --- a/migration/block.h
> +++ b/migration/block.h
> @@ -42,4 +42,5 @@ static inline uint64_t blk_mig_bytes_total(void)
>  #endif /* CONFIG_LIVE_BLOCK_MIGRATION */
>  
>  void migrate_set_block_enabled(bool value, Error **errp);
> +void block_migration_cleanup_bmds(void);
>  #endif /* MIGRATION_BLOCK_H */
> diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
> index e69c217aff..7540913767 100644
> --- a/stubs/Makefile.objs
> +++ b/stubs/Makefile.objs
> @@ -19,6 +19,7 @@ stub-obj-y += is-daemonized.o
>  stub-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
>  stub-obj-y += machine-init-done.o
>  stub-obj-y += migr-blocker.o
> +stub-obj-y += block-migration.o
>  stub-obj-y += change-state-handler.o
>  stub-obj-y += monitor.o
>  stub-obj-y += notify-event.o
> diff --git a/stubs/block-migration.c b/stubs/block-migration.c
> new file mode 100644
> index 0000000000..855f15c757
> --- /dev/null
> +++ b/stubs/block-migration.c
> @@ -0,0 +1,6 @@
> +#include "qemu/osdep.h"
> +#include "migration/block.h"
> +
> +void block_migration_cleanup_bmds(void)
> +{
> +}

You can add this inside include/migration/misc.h

#ifdef CONFIG_LIVE_BLOCK_MIGRATION
void blk_mig_init(void);
#else
static inline void blk_mig_init(void) {}

// And then you add the stub here?

#endif


Once here, I would consider to give one error/warning if we quit qemu
and we are in the middle of a block migration, no?

Thanks, Juan.